@article{AbdelhafezFawzyFahimetal.2018,
  author    = {Abdelhafez, Omnia Hesham and Fawzy, Michael Atef and Fahim, John Refaat and Desoukey, Samar Yehia and Krischke, Markus and Mueller, Martin J. and Abdelmohsen, Usama Ramadan},
  title     = {Hepatoprotective potential of Malvaviscus arboreus against carbon tetrachloride-induced liver injury in rats},
  series = {PLoS ONE},
  volume    = {13},
  journal   = {PLoS ONE},
  number    = {8},
  doi       = {10.1371/journal.pone.0202362},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177243},
  pages     = {e0202362},
  year      = {2018},
  abstract  = {Malvaviscus arboreus Cav. is a medicinal plant belonging to family Malvaceae with both ethnomedical and culinary value; however, its phytochemical and biological profiles have been scarcely studied. Accordingly, this work was designed to explore the chemical composition and the hepatoprotective potential of M. arboreus against carbon tetrachloride (CCl\(_4\))-induced hepatotoxicity. The total extract of the aerial parts and its derived fractions (petroleum ether, dichloromethane, ethyl acetate, and aqueous) were orally administered to rats for six consecutive days, followed by injection of CCl\(_4\) (1:1 v/v, in olive oil, 1.5 ml/kg, i.p.) on the next day. Results showed that the ethyl acetate and dichloromethane fractions significantly alleviated liver injury in rats as indicated by the reduced levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TB), and malondialdehyde (MDA), along with enhancement of the total antioxidant capacities of their livers, with the maximum effects were recorded by the ethyl acetate fraction. Moreover, the protective actions of both fractions were comparable to those of silymarin (100 mg/kg), and have been also substantiated by histopathological evaluations. On the other hand, liquid chromatography-high resolution electrospray ionization mass spectrometry (LC‒HR‒ESI‒MS) metabolomic profiling of the crude extract of M. arboreus aerial parts showed the presence of a variety of phytochemicals, mostly phenolics, whereas the detailed chemical analysis of the most active fraction (i.e. ethyl acetate) resulted in the isolation and identification of six compounds for the first time in the genus, comprising four phenolic acids; β-resorcylic, caffeic, protocatechuic, and 4-hydroxyphenylacetic acids, in addition to two flavonoids; trifolin and astragalin. Such phenolic principles, together with their probable synergistic antioxidant and liver-protecting properties, seem to contribute to the observed hepatoprotective potential of M. arboreus.},
  language  = {en}
}
@phdthesis{Abdelmohsen2010,
  author    = {Abdelmohsen, Usama Ramadan},
  title     = {Antimicrobial Activities from Plant Cell Cultures and Marine Sponge-Associated Actinomycetes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51483},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {This thesis is divided into three parts with the main goal allocating novel antimicrobial compounds that could be used as future antibiotics. The first part aimed to evaluate the potential of plant suspension cultures for the production of antimicrobial proteins. The extracellular, intracellular and cell wall bound fractions of seven heterotrophic and photomixotrophic plant cell suspension cultures treated with nine different elicitors were tested for the elicitor dependent production of antimicrobial proteins. Bioactivities were tested against a selected panel of human isolates including Gram-positive and Gram-negative bacteria as well as fungi using the disc diffusion assay. The intracellular fractions of elicited cell cultures were more active than extracellular fractions while the cell wall bound fractions showed lowest activities. Among the 21 fractions tested, the intracellular fraction of Lavendula angustifolia elicited with DC3000 was most active against Candida maltosa. The second most active fraction was the intracellular fraction of Arabidopsis thaliana elicited with salicylic acid which was moreover active against all test strains. The antimicrobial activity of elicited Arabidopsis thaliana cell cultures was tested by bioautography to locate the antimicrobial proteins in the crude extract. The intracellular fraction of photomixotrophic Arabidopsis thaliana cells elicited with salicylic acid was selected for further gel filtration chromatography on S-200 column leading to the purification of one 19 kDa antimicrobially active protein, designated, AtAMP. Our findings suggest that elicited plant cell cultures may present a new promising alternative source of antimicrobial proteins. The second part comprises the isolation of actinomycetes associated with marine sponges and testing the bioactivities of new species for further investigations. Actinobacterial communities of eleven taxonomically different sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia) were investigated by a culture-based approach using different standard media for isolation of actinomycetes and media enriched with aqueous sponge extract to target rare and new actinomycete species. Phylogenetic characterization of 52 representative isolates out of 90 based on almost complete sequences of genes encoding 16S rRNA supported their assignment to 18 different actinomycete genera. Altogether 14 putatively new species were identified based on sequence similarity values below 98.2\% to other strains in the NCBI database. The use of M1 agar amended with aqueous sponge extract yielded a putative new genus related to Rubrobacter which highlighting the need for innovative cultivation protocols. Biological activity testing showed that five isolates were active against Gram-positives only, one isolate was active against Candida albicans only and one isolate showed activity against both groups of pathogens. Moreover, the antiparasistic activity was documented for four isolates. These results showed a high diversity of actinomycetes associated with marine sponges as well as highlighted their potential to produce anti-infective agents. The third part of the thesis focused on the isolation and structure elucidation of new bioactive compounds. Streptomyces strain RV15 recovered from sponge Dysidea tupha, was selected for further chemical analysis by virtue of the fact that it exhibited the greatest antimicrobial potential against Staphylococcus aureus as well as Candida albicans among the all tested strains. Moreover, members of the genus Streptomyces are well known as prolific producers of interesting pharmacologically active metabolites. Chemical analysis of the methanolic crude extract using different chromatographic tools yielded four new compounds. The structures of the new compounds were spectroscopically elucidated to be four new cyclic peptides, namely, cyclodysidins A-D. Their bioactivity was tested against different proteases, bacteria and Candida as well as tumor cell lines. The compounds did not show any significant activities at this point.},
  subject      = {Antimikrobieller Wirkstoff},
  language  = {en}
}
@article{AbdelmohsenChengViegelmannetal.2014,
  author    = {Abdelmohsen, Usama Ramadan and Cheng, Cheng and Viegelmann, Christina and Zhang, Tong and Grkovic, Tanja and Ahmed, Safwat and Quinn, Ronald J. and Hentschel, Ute and Edrada-Ebel, RuAngelie},
  title     = {Dereplication Strategies for Targeted Isolation of New Antitrypanosomal Actinosporins A and B from a Marine Sponge Associated-Actinokineospora sp EG49},
  series = {Marine Drugs},
  volume    = {12},
  journal   = {Marine Drugs},
  number    = {3},
  issn      = {1660-3397},
  doi       = {10.3390/md12031220},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119876},
  pages     = {1220-44},
  year      = {2014},
  abstract  = {High resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy were employed as complementary metabolomic tools to dereplicate the chemical profile of the new and antitrypanosomally active sponge-associated bacterium Actinokineospora sp. EG49 extract. Principal Component (PCA), hierarchical clustering (HCA), and orthogonal partial least square-discriminant analysis (OPLS-DA) were used to evaluate the HRFTMS and NMR data of crude extracts from four different fermentation approaches. Statistical analysis identified the best culture one-strain-many-compounds (OSMAC) condition and extraction procedure, which was used for the isolation of novel bioactive metabolites. As a result, two new O-glycosylated angucyclines, named actinosporins A (1) and B (2), were isolated from the broth culture of Actinokineospora sp. strain EG49, which was cultivated from the Red Sea sponge Spheciospongia vagabunda. The structures of actinosporins A and B were determined by 1D- and 2D-NMR techniques, as well as high resolution tandem mass spectrometry. Testing for antiparasitic properties showed that actinosporin A exhibited activity against Trypanosoma brucei brucei with an IC₅₀ value of 15 µM; however no activity was detected against Leishmania major and Plasmodium falciparum, therefore suggesting its selectivity against the parasite Trypanosoma brucei brucei; the causative agent of sleeping sickness.},
  language  = {en}
}
@article{AbdelmohsenPimentelElardoHanoraetal.2010,
  author    = {Abdelmohsen, Usama Ramadan and Pimentel-Elardo, Sheila M. and Hanora, Amro and Radwan, Mona and Abou-El-Ela, Soad H. and Ahmed, Safwat and Hentschel, Ute},
  title     = {Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68307},
  year      = {2010},
  abstract  = {Terrestrial actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2\% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents.},
  subject      = {Biologie},
  language  = {en}
}
@article{AbdelmohsenSzesnyOthmanetal.2012,
  author    = {Abdelmohsen, Usama Ramadan and Szesny, Matthias and Othman, Eman Maher and Schirmeister, Tanja and Grond, Stepanie and Stopper, Helga and Hentschel, Ute},
  title     = {Antioxidant and Anti-Protease Activities of Diazepinomicin from the Sponge-Associated Micromonospora Strain RV115},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76279},
  year      = {2012},
  abstract  = {Diazepinomicin is a dibenzodiazepine alkaloid with an unusual structure among the known microbial metabolites discovered so far. Diazepinomicin was isolated from the marine sponge-associated strain Micromonospora sp. RV115 and was identified by spectroscopic analysis and by comparison to literature data. In addition to its interesting preclinical broad-spectrum antitumor potential, we report here new antioxidant and anti-protease activities for this compound. Using the ferric reducing antioxidant power (FRAP) assay, a strong antioxidant potential of diazepinomicin was demonstrated. Moreover, diazepinomicin showed a significant antioxidant and protective capacity from genomic damage induced by the reactive oxygen species hydrogen peroxide in human kidney (HK-2) and human promyelocytic (HL-60) cell lines. Additionally, diazepinomicin inhibited the proteases rhodesain and cathepsin L at an IC50 of 70-90 μM. It also showed antiparasitic activity against trypomastigote forms of Trypanosoma brucei with an IC50 of 13.5 μM. These results showed unprecedented antioxidant and anti-protease activities of diazepinomicin, thus further highlighting its potential as a future drug candidate.},
  subject      = {Biologie},
  language  = {en}
}
@article{AbdelmohsenYangHornetal.2014,
  author    = {Abdelmohsen, Usama Ramadan and Yang, Chen and Horn, Hannes and Hajjar, Dina and Ravasi, Timothy and Hentschel, Ute},
  title     = {Actinomycetes from Red Sea Sponges: Sources for Chemical and Phylogenetic Diversity},
  doi       = {10.3390/md12052771},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112882},
  year      = {2014},
  abstract  = {The diversity of actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2\% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive actinomycetes with potential for drug discovery.},
  subject      = {Meeresschw{\"a}mme},
  language  = {en}
}
@article{AdelfingerBesslerCeciletal.2015,
  author    = {Adelfinger, Marion and Bessler, Simon and Cecil, Alexander and Langbein-Laugwitz, Johanna and Frentzen, Alexa and Gentschev, Ivaylo and Szalay, Aladar A.},
  title     = {Preclinical Testing Oncolytic Vaccinia Virus Strain GLV-5b451 Expressing an Anti-VEGF Single-Chain Antibody for Canine Cancer Therapy},
  series = {Viruses},
  volume    = {7},
  journal   = {Viruses},
  doi       = {10.3390/v7072811},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125705},
  pages     = {4075-4092},
  year      = {2015},
  abstract  = {Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for canine cancer therapy. Here we describe, for the first time, the characterization and the use of VACV strain GLV-5b451 expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as therapeutic agent against different canine cancers. Cell culture data demonstrated that GLV-5b451 efficiently infected and destroyed all four tested canine cancer cell lines including: mammary carcinoma (MTH52c), mammary adenoma (ZMTH3), prostate carcinoma (CT1258), and soft tissue sarcoma (STSA-1). The GLV-5b451 virus-mediated production of GLAF-2 antibody was observed in all four cancer cell lines. In addition, this antibody specifically recognized canine VEGF. Finally, in canine soft tissue sarcoma (CSTS) xenografted mice, a single systemic administration of GLV-5b451 was found to be safe and led to anti-tumor effects resulting in the significant reduction and substantial long-term inhibition of tumor growth. A CD31-based immuno-staining showed significantly decreased neo-angiogenesis in GLV-5b451-treated tumors compared to the controls. In summary, these findings indicate that GLV-5b451 has potential for use as a therapeutic agent in the treatment of CSTS.},
  language  = {en}
}
@phdthesis{Ali2007,
  author    = {Ali, Walid Wahid},
  title     = {Screening of plant suspension cultures for antimicrobial activities and characterization of antimicrobial proteins from Arabidopsis thaliana},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-24358},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2007},
  abstract  = {Die zunehmende Resistenz humanpathogener Mikroorganismen gegen bekannte Antibiotika bedingt die Notwendigkeit, nach neuen Quellen f{\"u}r die Produktion antimikrobieller Stoffe zu suchen. Als eine solche Quelle gelten besonders Pflanzen, da viele antimikrobielle Stoffe bei der Abwehr gegen invasierende Mikroorganismen bilden. Das Ziel der vorliegenden Arbeit besteht in der Charakterisierung von pflanzlichen Zellkulturen im Hinblick auf ihre F{\"a}higkeit, anitimkrobielle Aktivit{\"a}t gegen humanpathogene Mikroorganismen zu entwickeln. Dabei sollen aktive Proteine aufgereinigt und die kodierenden Gene isoliert werden. Dazu wurden zehn verschiede pflanzliche Suspensionskulturen in Anwesenheit von neun Elicitoren auf ihre antimikrobielle Aktivit{\"a}t gegen f{\"u}nf humanpathogene Mikroorganismen getestet. Dabei erwiesen sich die heterotrophen Kulturen im Vergleich zu den autotrophen als aktiver. Die h{\"o}chste antimikrobielle Aktivit{\"a}t wurde bei der intrazellul{\"a}ren Fraktion der mixotrophen Kultur von Arabidopsis thaliana nach Elicitierung mit Salicyls{\"a}ure nachgewiesen. Da in einem Pr{\"a}zipitat mit Ammoniumsulfat Aktivit{\"a}t gegen Candida maltosa nachgewiesen wurde, konnte angenommen werden, dass es sich bei der aktiven Komponente um ein Protein handelt. Durch Hochgeschwindigkeitszentrifugation wurde eine partielle Aufreinigung dieser aktiven Komponente erreicht. Die proteinoide Natur wurde durch Bioautographie best{\"a}tigt und das Molekulargewicht auf ca. 26kDa gesch{\"a}tzt. Mittels Gelfiltration und Massenspektrometrie wurde das Protein aufgereinigt. Die Mikrosequenzierung ergab ein Protein mit bisher unbekannter Funktion, das eine pflanzliche Stressdom{\"a}ne (PLAT) enth{\"a}lt. Das Protein wurde daraufhin als AtPDP1 (Arabidopsis thaliana Plat-Domain Protein 1) bezeichnet. Das Gen und ein zweites mit hochgradiger Homologie (AtPDP2) wurden in E. coli kloniert. Der Digital Northern zeigt an, das beide Gene durch verschiedene Pathogene induziert werden, sowie von Chemikalien, die pflanzliche Abwehr hervorrufen und weiterhin von Phytohormonen. Der Versuch, AtPDP1 unter die Kontrolle eines Promors einer Proteinase zu stellen, der Induzierbarkeit durch Elicitoren vermittelt, blieb erfolglos. Weiterhin wurden 13 Thaumatingene aus Arabidopsis thaliana in E. coli kloniert, da ihre antimikrobielle Aktivit{\"a}t bekannt ist, und ihre Expression durch verschiedene Stimuli induziert wird. Von diesen Genen zeigt der Digital Northern bei allen Stimuli eine maximale Expression f{\"u}r At1g75800, w{\"a}hrend At1g75050 minimal induziert ist. Diese Gene stehen f{\"u}r zuk{\"u}nftige Studien zur Verf{\"u}gung.},
  subject      = {-},
  language  = {en}
}
@article{AmatobiOzbekUnalSchaebleretal.2023,
  author    = {Amatobi, Kelechi M. and Ozbek-Unal, Ayten Gizem and Sch{\"a}bler, Stefan and Deppisch, Peter and Helfrich-F{\"o}rster, Charlotte and Mueller, Martin J. and Wegener, Christian and Fekete, Agnes},
  title     = {The circadian clock is required for rhythmic lipid transport in Drosophila in interaction with diet and photic condition},
  series = {Journal of Lipid Research},
  volume    = {64},
  journal   = {Journal of Lipid Research},
  number    = {10},
  doi       = {10.1016/j.jlr.2023.100417},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349961},
  pages     = {100417},
  year      = {2023},
  abstract  = {Modern lifestyle is often at odds with endogenously driven rhythmicity, which can lead to circadian disruption and metabolic syndrome. One signature for circadian disruption is a reduced or altered metabolite cycling in the circulating tissue reflecting the current metabolic status. Drosophila is a well-established model in chronobiology, but day-time dependent variations of transport metabolites in the fly circulation are poorly characterized. Here, we sampled fly hemolymph throughout the day and analyzed diacylglycerols (DGs), phosphoethanolamines (PEs) and phosphocholines (PCs) using LC-MS. In wild-type flies kept on sugar-only medium under a light-dark cycle, all transport lipid species showed a synchronized bimodal oscillation pattern with maxima at the beginning and end of the light phase which were impaired in period01 clock mutants. In wild-type flies under constant dark conditions, the oscillation became monophasic with a maximum in the middle of the subjective day. In strong support of clock-driven oscillations, levels of the targeted lipids peaked once in the middle of the light phase under time-restricted feeding independent of the time of food intake. When wild-type flies were reared on full standard medium, the rhythmic alterations of hemolymph lipid levels were greatly attenuated. Our data suggest that the circadian clock aligns daily oscillations of DGs, PEs, and PCs in the hemolymph to the anabolic siesta phase, with a strong influence of light on phase and modality.},
  language  = {en}
}
@phdthesis{Angermeier2011,
  author    = {Angermeier, Hilde Gabriele},
  title     = {Molecular and ecological investigations of Caribbean sponge diseases},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-56855},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {W{\"a}hrend gewinnbringende Assoziationen von Schw{\"a}mmen mit Mikroorganismen in den letzten Jahren viel Aufmerksamkeit erhalten haben, wurde weit weniger in die Interaktion von Schw{\"a}mmen mit m{\"o}glicherweise pathogenen Mikroben investiert. Somit war es das Ziel dieser Studie zwei ausgew{\"a}hlte Karibische Schwammkrankheiten namens „Sponge Orange Band" und „Sponge White Patch" mittels {\"o}kologischer und molekularer Methoden zu untersuchen. Die Sponge Orange Band (SOB) Erkrankung bef{\"a}llt den bedeutenden karibischen Fass-Schwamm Xestospongia muta, der zu den bakterienhaltigen (HMA) Schw{\"a}mmen gez{\"a}hlt wird, w{\"a}hrend die Sponge White Patch (SWP) Erkrankung den h{\"a}ufig vorkommenden Seil-Schwamm Amphimedon compressa betrifft, der zu den bakterienarmen (LMA) Schw{\"a}mmen geh{\"o}rt. F{\"u}r beide Karibischen Schwammkrankheiten konnte ich einen Krankheitsverlauf beschreiben, der mit massiver Gewebszerst{\"o}rung und dem Verlust charakteristischer mikrobieller Signaturen einhergeht. Obwohl ich zeigen konnte, dass zus{\"a}tzliche Bakterienarten die gebleichten Schwammbereiche kolonisieren, lieferten meine Infektionsversuche in beiden F{\"a}llen keinen Beweis f{\"u}r die Beteiligung eines mikrobiellen Pathogens als Krankheitserreger. Somit liegen die eigentlichen Ausl{\"o}ser der Erkrankungen Sponge Orange Band als auch Sponge White Patch noch immer im Dunkeln.},
  subject      = {Meeresschw{\"a}mme},
  language  = {en}
}
@phdthesis{Anschuetz2008,
  author    = {Ansch{\"u}tz, Uta},
  title     = {Physiologie und Biophysik der pflanzlichen Glutamatrezeptoren},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29438},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {In vorausgegangenen Experimenten unseres Labors war bereits gezeigt worden, dass die Applikation von Glutamat zur transienten Erh{\"o}hung der cytosolischen Calciumkonzentration sowie zu einer Depolarisation der Plasmamembran von Mesophyllzellen f{\"u}hrt. Pharmakologische Studien weisen auf m{\"o}gliche Orthologe tierischer ionotroper Glutamatrezeptoren (iGLuRs) hin. Ziel dieser Arbeit war eine vertiefte molekulare und funktionelle Analyse der Glutamatrezeptoren (GLRs) aus Arabidopsis thaliana. Dabei konnten folgende Erkenntnisse gewonnen werden: i. Zugabe von extrazellul{\"a}rem Glutamat in Kombination mit Glycin f{\"u}hrt in Abh{\"a}ngigkeit der extrazellul{\"a}ren ATP-Konzentration (eATP) zu einer transienten Erh{\"o}hung der Calciumkonzentration in Mesophyllzellen. ii. Die Reaktion von Mesophyllprotoplasten auf die Applikation von Glutamat und Glycin ist im Vergleich zum intakten Blatt stark reduziert, kann jedoch in Gegenwart von eATP oder Glucose signifikant gesteigert werden. iii. Diese Responsibilit{\"a}t von Mesophyllprotoplasten ist zum Zeitpunkt des Einsetzens der Zellwandsynthese (48h) am h{\"o}chsten. iv. In Patch-Clamp Experimenten f{\"u}hrt die photolytische Freisetzung von extrazellul{\"a}rem caged-Glutamat bei 34 \% der gemessenen A. thaliana Mesophyllprotoplasten zu einem verst{\"a}rkten Kationentransport {\"u}ber die Plasmamembran. Dieser Kationenstrom kann durch gleichzeitige Anwesenheit von extrazellul{\"a}rem ATP noch verst{\"a}rkt werden und ist durch einen Desensitivierungsprozess gekennzeichnet. Die Empfindlichkeit dieser Str{\"o}me gegen{\"u}ber Antagonisten tierischer iGluRs stellt eine Verbindung zu der Genfamilie der AtGLRs dar. v. Coexpressionexperimente ausgew{\"a}hlter AtGLRs geben erste Hinweise auf eine Homo- bzw. eine Heteromerbildung von AtGLR1.1 und AtGLR1.4. Aufgrund fehlender Kanalaktivit{\"a}t konnten einzelne, in Oozyten exprimierte AtGLRs bislang nicht funktionell charakterisiert werden. vi. Studien zur transienten und stabilen {\"U}berexpression im homologen Expressionssystem zeigen einen cytotoxischen Effekt bei funktioneller {\"U}berexpression ausgew{\"a}hlter AtGLRs. vii. Die Analyse der Stellung des Glutamatrezeptors 3.4 in k{\"a}lteregulierten Signalnetzwerken via Microarrays weist auf ein {\"u}berlappendes Aufgabenspektrum der Familie der AtGLRs hin. viii. Im Rahmen von Microarray Transkriptionsanalysen an der glr3.4-1 Mutante konnte ein bisher nicht charakterisiertes, co-reguliertes Protein identifiziert werden. Dieses Protein ist durch den Besitz einer transmembranen Region sowie einer ATP-Bindedom{\"a}ne charakterisiert und k{\"o}nnte einen m{\"o}glichen Regulator des AtGLR3.4-Kanals darstellen. ix. Die {\"U}berpr{\"u}fung einer m{\"o}glichen Beteiligung der pflanzlichen Glutamatrezeptoren an der Generierung der glutamatabh{\"a}ngigen Ca2+-Signale sowie die Suche nach Regulatoren bzw. fehlenden Untereinheiten erfolgte mithilfe Mutanten-„Sreenings". Die Analyse der bis dato identifizierten, Glutamat-insensitiven Mutanten konnte im Rahmen dieser Arbeit nicht abgeschlossen werden.},
  subject      = {Glutamate},
  language  = {de}
}
@phdthesis{Arand2010,
  author    = {Arand, Katja},
  title     = {Charakterisierung hydrophiler Permeationswege in der pflanzlichen Kutikula anhand der Permeationseigenschaften ionischer Aminos{\"a}uren},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49954},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Um sich vor dem Austrocknen zu sch{\"u}tzen, haben Pflanzen eine Transpirationsbarriere entwickelt, die als Membran alle prim{\"a}ren, oberirdischen Pflanzenteile {\"u}berzieht. Diese so genannte Kutikula besteht haupts{\"a}chlich aus den lipophilen Komponenten Kutin und Wachs und reduziert so effektiv den Verlust von Wasser und wasserl{\"o}slichen N{\"a}hrstoffen aus dem Blattinneren. Trotzdem ist sie nicht vollst{\"a}ndig undurchl{\"a}ssig, und so k{\"o}nnen Wasser und gel{\"o}ste Substanzen wie organische und anorganische N{\"a}hrstoffe, Pestizide oder Umweltchemikalien die Kutikula in beiden Richtungen permeieren. Dabei ist offensichtlich, dass die zu Grunde liegenden Transportmechanismen den Ern{\"a}hrungszustand der Pflanzen, die Effizienz von Pestiziden und die Wirkung von Umweltchemikalien beeinflussen. Ein genaues Verst{\"a}ndnis der Transportprozesse auf denen die kutikul{\"a}re Permeation basiert, kann helfen die Wirkweise von blattapplizierten D{\"u}nge- und Pflanzenschutzmitteln zu optimieren, indem gezielt Wirk- oder Zusatzstoffe modelliert werden k{\"o}nnen, welche die Aufnahme steigern. In der vorliegenden Arbeit sollte deshalb der Einfluss physiko-chemischer Eigenschaften von hydrophilen Verbindungen auf die kutikul{\"a}re Permeation untersucht werden. Nicht zuletzt wegen ihrer strukturellen {\"A}hnlichkeit mit den blattapplizierten Herbiziden Glufosinat und Glyphosat wurden Aminos{\"a}uren als Modellsubstenzen ausgew{\"a}hlt. Die verwendeten Aminos{\"a}uren sind gut wasserl{\"o}slich, wobei alle Oktanol/Wasser Verteilungskoeffizienten kleiner als 1 sind. Zus{\"a}tzlich liegen alle Aminos{\"a}uren in gel{\"o}ster Form als Ionen vor, was zu einer Hydratisierung der Molek{\"u}le f{\"u}hrt. Es wird spekuliert, dass hydratisierte Molek{\"u}le keinen Zugang zur lipophilen Phase der Kutikula haben. Welche Rolle die Hydrath{\"u}lle bei der Permeation tats{\"a}chlich spielt, ist allerdings noch unklar. Viele Aktivwirkstoffe liegen nur unter ganz bestimmten Bedingungen in geladener Form vor, w{\"a}hrend die Richtung der kontinuierlichen Nettoladung der Aminos{\"a}uren durch den pH Wert modifiziert wird. Damit kann der Einfluss verschiedener Ladungszust{\"a}nde auf die kutikul{\"a}re Permeation unter Verwendung eines einheitlichen Sets von Modellsubstanzen untersucht werden. Unter nat{\"u}rlichen Bedingungen sind Aminos{\"a}uren unter anderem auf Blattoberfl{\"a}chen zu finden, wo sie blattassoziierten Mikroorganismen eine profitable Nahrungsquelle bieten. Ob {\"a}ußere Faktoren f{\"u}r die Deposition dieser Recourcen verantwortlich sind, oder ob der Ursprung innerhalb des Blattgewebes liegt, wird kontrovers diskutiert. Die Sorption von Aminos{\"a}uren in isolierte Kutikularmembranen ist sehr gering, und korreliert - anders als bei lipophilen Substanzen - nicht mit dem Oktanol/Wasser Verteilungskoeffizienten. Das zeigt, dass der Verteilung von lipophilen und hydrophilen Substanzen innerhalb der Kutikula verschiedene Mechanismen zu Grunde liegen. Unter einer gegebenen Bedingung werden die kutikul{\"a}ren Leitwerte der Aminos{\"a}uren negativ vom Molvolumen beeinflusst. Zudem {\"u}bersteigt die L{\"a}nge des Permeationswegs die eigentliche Dicke der Membran um ein Vielfaches. Diese Zusammenh{\"a}nge kennzeichnen eine gehinderte Diffusion innerhalb einer engporigen und weit verzweigten Umgebung. Eine {\"A}nderung des pH Wertes wirkt sich in unterschiedlicher Form auf die Leitwerte von Wasser und Aminos{\"a}uren aus. Mit steigendem pH Wert erh{\"o}ht sich die Wasserpermeabilit{\"a}t isolierter Kutikularmembranen, was durch eine zunehmende, messbare Wassersorption in die Kutikula erkl{\"a}rt werden kann. Eine pH abh{\"a}ngige Dissoziation funktioneller Gruppen bewirkt eine Schwellung des polaren Weges, weshalb auch f{\"u}r die anionischen Aminos{\"a}uren bei pH 11 die h{\"o}chsten Leitwerte gemessen wurden. Die zwitterionischen Aminos{\"a}uren bei pH 6 wiesen hingegen die geringsten Leitwerte auf, was im Widerspruch zu der Beobachtung steht, dass bei pH 1 die geringste Wassersorption in die Kutikula stattfindet. Eine Erkl{\"a}rung hierf{\"u}r liefern die Hydrath{\"u}llen, die bei den zwitterionischen Aminos{\"a}uren am st{\"a}rksten und bei den anionischen Species am geringsten ausgepr{\"a}gt sind. Eine negative Korrelation aller gemessenen Aminos{\"a}ureleitwerte mit den entsprechenden hydratisierten Molvolumen zeigt eindeutig, dass die Hydrath{\"u}lle eine wichtige Gr{\"o}ße f{\"u}r die Permeation durch die Kutikula darstellt. Dabei nimmt der Leitwert einer hydrophilen Substanz mit definiertem Molvolumen mit kleiner werdender Hydrath{\"u}lle zu. Intakte Bl{\"a}tter wurden in fl{\"u}ssiges Wasser als Rezeptorl{\"o}sung getaucht, um steady-state Bedingungen aufrecht zu erhalten. Dabei konnte gezeigt werden, dass die Permeabilit{\"a}ten von intakten Kutikularmembranen, die anhand der nat{\"u}rlichen Aminos{\"a}urekonzentration innerhalb der Bl{\"a}tter bestimmt wurden, in derselben Gr{\"o}ßenordnung liegen, wie die f{\"u}r isolierte Membranen gemessenen. Außerdem konnte ein Vergleich der Flussraten auf der Ober- und Unterseite der Bl{\"a}tter zeigen, dass die stomat{\"a}ren Poren nicht direkt in den Leachingprozess involviert sind.},
  subject      = {Permeation},
  language  = {de}
}
@phdthesis{Asmus2016,
  author    = {Asmus, Elisabeth},
  title     = {Mode of Action of Adjuvants for Foliar Application},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-138159},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {Adjuvants are compounds added to an agrochemical spray formulation to improve or modify the action of an active ingredient (AI) or the physico-chemical characteristics of the spray liquid. Adjuvants can have more than only one distinct mode of action (MoA) during the foliar spray application process and they are generally known to be the best tools to improve agrochemical formulations. The main objective for this work was to elucidate the basic MoA of adjuvants by uncoupling different aspects of the spray application. Laboratory experiments, beginning from retention and spreading characteristics, followed by humectant effects concerning the spray deposit on the leaf surface and ultimately the cuticular penetration of an AI, were figured out to evaluate overall in vivo effects of adjuvants which were also obtained in a greenhouse spray test. For this comprehensive study, the surfactant classes of non-ionic sorbitan esters (Span), polysorbates (Tween) and oleyl alcohol polyglycol ether (Genapol O) were generally considered because of their common promoting potential in agrochemical formulations and their structural diversity. The reduction of interfacial tension is one of the most crucial physico-chemical properties of surfactants. The dynamic surface tension (DST) was monitored to characterise the surface tension lowering behaviour which is known to influence the droplet formation and retention characteristics. The DST is a function of time and the critical time frame of droplet impact might be at about 100 ms. None of the selected surfactants were found to lower the surface tension sufficiently during this short timeframe (chapter I). At ca. 100 ms, Tween 20 resulted in the lowest DST value. When surfactant monomers are fully saturated at the droplet-air-interface, an equilibrium surface tension (STeq) value can be determined which may be used to predict spreading or run-off effects. The majority of selected surfactants resulted in a narrow distribution of STeq values, ranging between 30 and 45 mN m- 1. Nevertheless, all surfactants were able to decrease the surface tension considerably compared to pure water (72 mN m- 1). The influence of different surfactants on the wetting process was evaluated by studying time-dependent static contact angles on different surfaces and the droplet spread area on Triticum aestivum leaves after water evaporation. The spreading potential was observed to be better for Spans than for Tweens. Especially Span 20 showed maximum spreading results. To transfer laboratory findings to spray application, related to field conditions, retention and leaf coverage was measured quantitatively on wheat leaves by using a variable track sprayer. Since the retention process involves short time dynamics, it is well-known that the spray retention on a plant surface is not correlated to STeq but to DST values. The relationship between DST at ca. 100 ms and results from the track sprayer showed increasing retention results with decreasing DST, whereas at DST values below ca. 60 mN m- 1 no further retention improvement could be observed. Under field conditions, water evaporates from the droplet within a few seconds to minutes after droplet deposition on the leaf surface. Since precipitation of the AI must essentially being avoided by holding the AI in solution, so-called humectants are used as tank-mix adjuvants. The ability of pure surfactants to absorb water from the surrounding atmosphere was investigated comprehensively by analysing water sorption isotherms (chapter II). These isotherms showed an exponential shape with a steep water sorption increase starting at 60\% to 70\% RH. Water sorption was low for Spans and much more distinct for the polyethoxylated surfactants (Tweens and Genapol O series). The relationship between the water sorption behaviour and the molecular structure of surfactants was considered as the so-called humectant activity. With an increasing ethylene oxide (EO) content, the humectant activity increased concerning the particular class of Genapol O. However, it could be shown that the moisture absorption across all classes of selected surfactants correlates rather better with their hydrophilic-lipophilic balance values with the EO content. All aboveground organs of plants are covered by the cuticular membrane which is therefore the first rate limiting barrier for AI uptake. In vitro penetration experiments through an astomatous model cuticle were performed to study the effects of adjuvants on the penetration of the lipophilic herbicide Pinoxaden (PXD) (chapter III). In order to understand the influence of different adjuvant MoA like humectancy, experiments were performed under three different humidity levels. No explicit relationship could be found between humidity levels and the PXD penetration which might be explained by the fact that humidity effects would rather affect hydrophilic AIs than lipophilic ones. Especially for Tween 20, it became obvious that a complex balance between multiple MoA like spreading, humectancy and plasticising effects have to be considered. Greenhouse trials, focussing the adjuvant impact on in vivo action of PXD, were evaluated on five different grass-weed species (chapter III). Since agrochemical spray application and its following action on living plants also includes translocation processes in planta and species dependent physiological effects, this investigation may help to simulate the situation on the field. Even though the absolute weed damage was different, depending both on plant species and also on PXD rates, adjuvant effects in greenhouse experiments displayed the same ranking as in cuticular penetration studies: Tween 20 > Tween 80 > Span 20 ≥ Span 80. Thus, the present work shows for the first time that findings obtained in laboratory experiments can be successfully transferred to spray application studies on living plants concerning adjuvant MoA. A comparative analysis, using radar charts, could demonstrate systematic derivations from structural similarities of adjuvants to their MoA (summarising discussion and outlook). Exemplarily, Tween 20 and Tween 80 cover a wide range of selected variables by having no outstanding MoA improving one distinct process during foliar application, compared to non-ethoxylated Span 20 and Span 80 which primarily revealed a surface active action. Most adjuvants used in this study represent polydisperse mixtures bearing a complex distribution of EO and aliphatic chains. From this study it seems alike that adjuvants having a wide EO distribution offer broader potential than adjuvants with a small EO distribution. It might be a speculation that due to this broad distribution of single molecules, all bearing their individual specific physico-chemical nature, a wide range of properties concerning their MoA is covered.},
  subject      = {Adjuvans},
  language  = {en}
}
@phdthesis{Attaran2010,
  author    = {Attaran, Elham},
  title     = {Regulation of pathogen-inducible volatile compounds in Arabidopsis and their role in plant defense},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46715},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Plants are constantly attacked by pathogenic microbes. As a result, they have evolved a plethora of constitutive and inducible defense responses to defend against attempted pathogen infection. Although volatile organic compounds have been implicated in plant defense, direct evidence of their function in plant resistance is still lacking. I have examined the role of VOCs in Arabidopsis defense against the hemibiotrophic bacterial pathogen Pseudomonas syringae pv. maculicola. The obtained results show that the vegetative parts of Arabidopsis produces and emits the volatile phenylpropanoid MeSA and three kinds of terpenoids, (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT), alpha-ionon and beta-farnesen, upon avirulent and virulent P. syringae inoculation. Whereas the most abundant volatiles, MeSA and TMTT, are already produced at early stages of infection in the compatible and incompatible interaction, enhanced emission of alpha-ionon and beta-farnesen can only be detected in later stages of the compatible interaction. It was revealed that pathogen-induced synthesis of TMTT in Arabidopsis requires the JA signaling pathway but occurs independently of SA defense signaling. Similarly, the production of MeSA is dependent on JA signaling but not on the SA defense signaling pathway. Furthermore, production of MeSA is dependent on the function of ISOCHORISMATE SYNTHASE1, which produces its precursor SA. Upon inoculation with avirulent P. syringae, endogenously produced JA activates the JA signalling pathway to mediate MeSA and TMTT synthesis. By contrast, in the compatible Arabidopsis-Psm interaction, production of MeSA predominantly depends on the P. syringea the virulence factor coronatine, which activates JA downstream signaling. To learn more about the role of inducible VOCs in plant defense responses, I have identified an Arabidopsis T-DNA insertions line with a defect in the TERPENE SYNTHASE4 (TPS4) gene. Emission profiles from this mutant revealed that the induced production of TMTT but not of alpha-ionone, beta-farnesene or MeSA are abolished, demonstrating that TPS4 specifically regulates the P. syringae-induced synthesis of TMTT in Arabidopsis. The lack of TMTT in tps4 mutants, however, does not affect plant defense responses and resistance induction against P. syringae. This excludes a role of the terpenoid as an effective phytoalexin in Arabidopsis leaves against the bacterial pathogen. Moreover, tps4 mutant plants are still able to mount a SAR response, excluding a signaling function of TMTT during SAR. An important aim of our studies was to address the defensive role of MeSA, the major VOC emitted from P. syringae-inoculated Arabidopsis leaves. MeSA has been recently proposed as a critical long distance signal in the development of SAR. I found that two independent T-DNA insertions lines with defects in expression of the pathogen-inducible SA methyl transferase gene BSMT1 are completely devoid of pathogen-induced production of MeSA. However, bsmt1 mutant plants are capable to increase the level of SA in systemic, non-infected leaves of Arabodopsis and develop SAR like wild-type plants upon local P. syringae-inoculation. Thus, MeSA does not function as a critical SAR signal in Arabidopsis. Further experiments showed that SA accumulation in distant leaves occurs due to de novo synthesis through isochorismate synthase. In addition, we also ruled out a critical defensive role of MeSA at inoculation sites, because bsmt1 mutants are able to build up SA-dependent defense responses and local resistance in a wild-type-like manner. The conversion of SA to MeSA and subsequently emission of MeSA from the plant might help the plant to detoxify an excess of SA. This process is regulated by the JA pathway and might be one means to mediate negative crosstalk between JA and SA signaling. Moreover, the COR-triggered conversion of SA to MeSA and emission of the volatile methyl ester could be a way by which virulent P. syringae is able to attenuate the SA-defense pathway.},
  subject      = {Ackerschmalwand},
  language  = {en}
}
@article{BalasubramanianOthmanKampiketal.2017,
  author    = {Balasubramanian, Srikkanth and Othman, Eman M. and Kampik, Daniel and Stopper, Helga and Hentschel, Ute and Ziebuhr, Wilma and Oelschlaeger, Tobias A. and Abdelmohsen, Usama R.},
  title     = {Marine sponge-derived Streptomyces sp SBT343 extract inhibits staphylococcal biofilm formation},
  series = {Frontiers in Microbiology},
  volume    = {8},
  journal   = {Frontiers in Microbiology},
  doi       = {10.3389/fmicb.2017.00236},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171844},
  year      = {2017},
  abstract  = {Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and non-proteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation without interfering with bacterial cell viability. Due to absence of cell toxicity, the extract might represent a good starting material to develop a future remedy to block staphylococcal biofilm formation on contact lenses and thereby to prevent intractable contact lens-mediated ocular infections.},
  language  = {en}
}
@phdthesis{Baumann2013,
  author    = {Baumann, Melanie},
  title     = {Optogenetische Simulation und Analyse elektrischer und Calcium-basierter Signale in Pflanzen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87974},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Funktionelle Expression von ChR2 in Pflanzen In der vorliegenden Arbeit konnte erstmalig die funktionelle Expression des licht-aktivierten Channelrhodopsin-2 aus Chlamydomonas reinhardtii in h{\"o}heren Pflanzen gezeigt werden. Obwohl die erfolgreiche Transformation auf der Basis der Integration einer Expressionskassette f{\"u}r WT-ChR2 in Pflanzen genetisch nachgewiesen werden konnte, war ein funktioneller Nachweis nicht m{\"o}glich. Demgegen{\"u}ber war die funktio-nelle Expression aller getesteten ChR2-Mutanten im transienten Expressionsansatz er-folgreich und konnte schließlich auf der Basis der im Rahmen dieser Arbeit generierten Konstrukte auch f{\"u}r stabil transformierte Arabidopsis-Pflanzen best{\"a}tigt werden. ChR2 wurde in Arabidopsis-Protoplasten sowie Tabak-Epidermis- und Mesophyllzellen an der Plasmamembran lokalisiert, zeigte jedoch aufgrund der {\"U}berexpression eine starke {\"U}berladung des Endomembransystems. Elektrophysiologische Messungen mit Hilfe der Einstichtechnik belegten, dass ChR2 sowohl in Arabidopsis-Keimlingen als auch im Tabakmesophyll funktionell ist, wobei sich die erzeugten Blaulicht-vermittelten Depolarisationen weitaus erfolgreicher im Ta-baksystem darstellten. Alle eingesetzten ChR2-Mutanten waren funktionell und zeigten in Einstichmessungen mit Oozytendaten korrelierende Kinetiken. Die Mutante C128A wurde hinsichtlich der erzielten lichtinduzierten Membranpotentialdepolarisationen als effektivste ChR2-Variante identifiziert. Calcium-Messungen mit dem Reporterprotein Aequorin lieferten keinen Beweis f{\"u}r einen direkt durch ChR2-C128A vermittelten Calcium-Einstrom in Arabidopsis-Protoplasten. Jedoch konnte ein cytosolischer Calcium-Anstieg ca. 3min nach Blau-lichtapplikation beobachtet werden. Dies deutet darauf hin, dass die durch ChR2 vermittelten Membranpotential{\"a}nderungen zu einer Aktivierung endogener, Calcium-permeabler Ionenkan{\"a}le f{\"u}hren k{\"o}nnte. F{\"u}r die ChR2-L132C Mutante konnte allerdings in ersten Messungen ein direkter Calcium-Anstieg nach Lichtgabe beobachtet werden.   Transkriptionelle {\"A}nderungen aufgrund ChR2-basierter, elektrischer Signalmuster In RNA-Seq-Analysen mit transient transformierten Tabakbl{\"a}ttern konnte die Bedeu-tung der Signalsignatur elektrischer bzw. Calcium-basierter Signale verifiziert werden: Die Applikation zweier in ihrer Form g{\"a}nzlich unterschiedlicher elektrischer Signal-muster lieferte ein signifikant unterschiedlich reguliertes Set an Genen, wobei einige wenige durch beide Behandlungen induziert werden konnten. Langanhaltende Depolari-sationen regulierten deutlich mehr Gene und waren daher in ihrer Wirkung weitaus ef-fektiver als kurze, repetitive Depolarisationen. Die bioinformatische Analyse dieser Daten zeigte, dass die Nachahmung eines im Zuge der Pathogenantwort bekannten, langen Depolarisationspulses Gene der Flagellin-induzierten Signaltransduktion adressierte, w{\"a}hrend kurze, wiederkehrende Pulse mit gleichem Informationsgehalt diese nicht regulierten.},
  subject      = {Channelrhodopsin-2},
  language  = {de}
}
@phdthesis{Beck2019,
  author    = {Beck, Sebastian},
  title     = {Using optogenetics to influence the circadian clock of \(Drosophila\) \(melanogaster\)},
  doi       = {10.25972/OPUS-18495},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184952},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Almost all life forms on earth have adapted to the most impactful and most predictable recurring change in environmental condition, the cycle of day and night, caused by the axial rotation of the planet. As a result many animals have evolved intricate endogenous clocks, which adapt and synchronize the organisms' physiology, metabolism and behaviour to the daily change in environmental conditions. The scientific field researching these endogenous clocks is called chronobiology and has steadily grown in size, scope and relevance since the works of the earliest pioneers in the 1960s. The number one model organism for the research of circadian clocks is the fruit fly, Drosophila melanogaster, whose clock serves as the entry point to understanding the basic inner workings of such an intricately constructed endogenous timekeeping system. In this thesis it was attempted to combine the research on the circadian clock with the techniques of optogenetics, a fairly new scientific field, launched by the discovery of Channelrhodopsin 2 just over 15 years ago. Channelrhodopsin 2 is a light-gated ion channel found in the green alga Chlamydomonas reinhardtii. In optogenetics, researches use these light-gated ion channels like Channelrhodopsin 2 by heterologously expressing them in cells and tissues of other organisms, which can then be stimulated by the application of light. This is most useful when studying neurons, as these channels provide an almost non-invasive tool to depolarize the neuronal plasma membranes at will. The goal of this thesis was to develop an optogenetic tool, which would be able to influence and phase shift the circadian clock of Drosophila melanogaster upon illumination. A phase shift is the adaptive response of the circadian clock to an outside stimulus that signals a change in the environmental light cycle. An optogenetic tool, able to influence and phase shift the circadian clock predictably and reliably, would open up many new ways and methods of researching the neuronal network of the clock and which neurons communicate to what extent, ultimately synchronizing the network. The first optogenetic tool to be tested in the circadian clock of Drosophila melanogaster was ChR2-XXL, a channelrhodopsin variant with dramatically increased expression levels and photocurrents combined with a prolonged open state. The specific expression of ChR2-XXL and of later constructs was facilitated by deploying the three different clock-specific GAL4-driver lines, clk856-gal4, pdf-gal4 and mai179-gal4. Although ChR2-XXL was shown to be highly effective at depolarizing neurons, these stimulations proved to be unable to significantly phase shift the circadian clock of Drosophila. The second series of experiments was conducted with the conceptually novel optogenetic tools Olf-bPAC and SthK-bPAC, which respectively combine a cyclic nucleotide-gated ion channel (Olf and SthK) with the light-activated adenylyl-cyclase bPAC. These tools proved to be quite useful when expressed in the motor neurons of instar-3 larvae of Drosophila, paralyzing the larvae upon illumination, as well as affecting body length. This way, these new tools could be precisely characterized, spawning a successfully published research paper, centered around their electrophysiological characterization and their applicability in model organisms like Drosophila. In the circadian clock however, these tools caused substantial damage, producing severe arrhythmicity and anomalies in neuronal development. Using a temperature-sensitive GAL80-line to delay the expression until after the flies had eclosed, yielded no positive results either. The last series of experiments saw the use of another new series of optogenetic tools, modelled after the Olf-bPAC, with bPAC swapped out for CyclOp, a membrane-bound guanylyl-cyclase, coupled with less potent versions of the Olf. This final attempt however also ended up being unsuccessful. While these tools could efficiently depolarize neuronal membranes upon illumination, they were ultimately unable to stimulate the circadian clock in way that would cause it to phase shift. Taken together, these mostly negative results indicate that an optogenetic manipulation of the circadian clock of Drosophila melanogaster is an extremely challenging subject. As light already constitutes the most impactful environmental factor on the circadian clock, the combination of chronobiology with optogenetics demands the parameters of the conducted experiments to be tuned with an extremely high degree of precision, if one hopes to receive positive results from these types of experiments at all.},
  subject      = {Chronobiologie},
  language  = {en}
}
@article{BeckYuStrzelczykPaulsetal.2018,
  author    = {Beck, Sebastian and Yu-Strzelczyk, Jing and Pauls, Dennis and Constantin, Oana M. and Gee, Christine E. and Ehmann, Nadine and Kittel, Robert J. and Nagel, Georg and Gao, Shiqiang},
  title     = {Synthetic light-activated ion channels for optogenetic activation and inhibition},
  series = {Frontiers in Neuroscience},
  volume    = {12},
  journal   = {Frontiers in Neuroscience},
  number    = {643},
  doi       = {10.3389/fnins.2018.00643},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177520},
  year      = {2018},
  abstract  = {Optogenetic manipulation of cells or living organisms became widely used in neuroscience following the introduction of the light-gated ion channel channelrhodopsin-2 (ChR2). ChR2 is a non-selective cation channel, ideally suited to depolarize and evoke action potentials in neurons. However, its calcium (Ca2\(^{2+}\)) permeability and single channel conductance are low and for some applications longer-lasting increases in intracellular Ca\(^{2+}\) might be desirable. Moreover, there is need for an efficient light-gated potassium (K\(^{+}\)) channel that can rapidly inhibit spiking in targeted neurons. Considering the importance of Ca\(^{2+}\) and K\(^{+}\) in cell physiology, light-activated Ca\(^{2+}\)-permeant and K\(^{+}\)-specific channels would be welcome additions to the optogenetic toolbox. Here we describe the engineering of novel light-gated Ca\(^{2+}\)-permeant and K\(^{+}\)-specific channels by fusing a bacterial photoactivated adenylyl cyclase to cyclic nucleotide-gated channels with high permeability for Ca\(^{2+}\) or for K\(^{+}\), respectively. Optimized fusion constructs showed strong light-gated conductance in Xenopus laevis oocytes and in rat hippocampal neurons. These constructs could also be used to control the motility of Drosophila melanogaster larvae, when expressed in motoneurons. Illumination led to body contraction when motoneurons expressed the light-sensitive Ca\(^{2+}\)-permeant channel, and to body extension when expressing the light-sensitive K\(^{+}\) channel, both effectively and reversibly paralyzing the larvae. Further optimization of these constructs will be required for application in adult flies since both constructs led to eclosion failure when expressed in motoneurons.},
  language  = {en}
}
@phdthesis{Beckert2002,
  author    = {Beckert, Cornelia},
  title     = {Biosynthese, Akkumulation und Strukturen von Styrylpyronen in gametophytischen und sporophytischen Geweben von Equisetum},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-3454},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2002},
  abstract  = {Untersuchungen zur Akkumulation phenolischer Inhaltsstoffe von Equisetum an gametophytischen und unterirdisch wachsenden sporophytischen Geweben vervollst{\"a}ndigten den Kenntnisstand der phenolischen Inhaltsstoffe in dieser Gattung. In beiden Geweben konnten - wie in oberirdischen sporophytischen Geweben - Hydroxyzimts{\"a}urederivate nachgewiesen werden. Styrylpyrone und Protoflavonoide ersetzen hier die in oberirdischen sporophytischen Geweben nachgewiesenen Flavonoide. Hydroxyzimts{\"a}urederivate wurden in Prothallien aller untersuchter Arten gefunden wohingegen in Rhizomen der jeweiligen Arten einzelne Hydroxyzimts{\"a}urederivate fehlten. Die Inhaltsstoffmuster der Styrylpyrone bei verschiedenen Arten entsprachen sich weitgehend. Die sukzessive Analyse des {\"U}bergangsbereiches - unterirdisch wachsendes Rhizom zu oberirdischem Spross - zeigte einen ebenso sukzessiven Wechsel im Akkumulationsmuster. Der Gehalt l{\"o}slicher Styrylpyrone nahm - von unten nach oben betrachtet - in gleichem Maße ab, wie der Gehalt an Flavonoiden anstieg. In lokal braun pigmentierten Sprossbereichen, die vereinzelt an oberirdisch wachsenden Sporophyten auftraten, wurden neben den in Rhizomen konstitutiv akkumulierten Styrylpyronen auch, offenbar durch Verwundung induziert, Styrylpyrone detektiert. In den gr{\"u}nen, nicht pigmentierten Bereichen dieser Sprosse wurden dagegen ausschließlich Flavonoide und Hydroxyzimts{\"a}urederivate detektiert. Fluoreszenzmikroskopische Untersuchungen belegten eine vakuol{\"a}re Speicherung der l{\"o}slichen Inhaltsstoffe Styrylpyrone und Hydroxyzimts{\"a}urederivate in Rhizomen und Prothallien. Hydroxyzimts{\"a}urederivate wurden vorwiegend in zentral liegenden Rhizombereichen detektiert, w{\"a}hrend Styrylpyrone {\"u}ber den gesamten Rhizomquerschnitt verteilt sichtbar gemacht werden konnten. Folgende Styrylpyrone wurden aus Rhizomen von E. arvense isoliert und mit Hilfe spektroskopischer Methoden in ihrer Struktur aufgekl{\"a}rt: 3,4-Dihydroxy-6-(4´-hydroxy-E-styryl)-2-pyron-3-O-ß-D-glucopyranosid und 3,4-Dihydroxy-6-(3´-hydroxy-4´methoxy-E-styryl)-2-pyron-3-O-ß-glucopyranosid. Untersuchungen zur Biosynthese von Styrylpyronen zeigten eine enzymkatalysierte Bildung von Hispidin und Bisnoryangonin in Gametophyten verschiedener Equisetum-Arten sowie in Rhizomen und fertilen Sporophyten von E. arvense. Ebenso gelang der Nachweis der enzymatischen Glycosilierung von 3-Hydroxyhispidin zu Equisetumpyron in Gametophyten von E. arvense. Eine Styrylpyronsynthase wurde charakterisiert: Das pH-Optimum f{\"u}r die Bildung von Bisnoryangonin lag bei pH 7,5-7,8 und f{\"u}r die Bildung von Hispidin bei 6,8-7,0, jeweils in 0,5 M KPi-Puffer. Das Temperaturoptimum f{\"u}r die Bildung von Bisnoryangonin betrug 30° C bzw. 37°C f{\"u}r die Bildung von Hispidin. Die Substanzen Natriumascorbat in einer Konzentration von 20 mM, BSA (0,1 \% w/V), Dithiothreitol (2,5 mM) bzw. Mercaptoethanol (7 mM) konnten die Enzymaktivit{\"a}t deutlich steigern. Die Km\&\#64979;Werte wurden f{\"u}r die Substrate Kaffeoyl-CoA und Malonyl-CoA bei 116 µM bzw. 141 µM ermittelt. F{\"u}r die Substrate p-Cumaroyl-CoA und Malonyl-CoA lagen die Km\&\#64979;Werte bei 182 µM bzw. 238 µM. Das relative Molekulargewicht des nativen Enzyms wurde mittels Gelfiltration mit 78-80 kD bestimmt. Im Rahmen der Proteinreinigung wurde eine auf chromatographischen Techniken basierende Methode entwickelt, mit der die Styrylpyronsynthase mit einem Anreicherungsfaktor von 1107 bei einer Ausbeute von 0,08 \% gereinigt werden konnte.},
  subject      = {Schachtelhalm},
  language  = {de}
}
@phdthesis{Bellwon2015,
  author    = {Bellwon, Patricia},
  title     = {Kinetic assessment by in vitro approaches - A contribution to reduce animals in toxicity testing},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122693},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {The adoption of directives and regulations by the EU requires the development of alternative testing strategies as opposed to animal testing for risk assessment of xenobiotics. Additionally, high attrition rates of drugs late in the discovery phase demand improvement of current test batteries applied in the preclinical phase within the pharmaceutical area. These issues were taken up by the EU founded 7th Framework Program "Predict-IV"; with the overall goal to improve the predictability of safety of an investigational product, after repeated exposure, by integration of "omics" technologies applied on well established in vitro approaches. Three major target organs for drug-induced toxicity were in focus: liver, kidney and central nervous system. To relate obtained dynamic data with the in vivo situation, kinetics of the test compounds have to be evaluated and extrapolated by physiologically based pharmacokinetic modeling. This thesis assessed in vitro kinetics of the selected test compounds (cyclosporine A, adefovir dipivoxil and cisplatinum) regarding their reliability and relevance to respective in vivo pharmacokinetics. Cells were exposed daily or every other day to the test compounds at two concentration levels (toxic and non-toxic) for up to 14 days. Concentrations of the test compounds or their major biotransformation products were determined by LC-MS/MS or ICP-MS in vehicle, media, cells and plastic adsorption samples generated at five different time-points on the first and the last treatment day. Cyclosporine A bioaccumulation was evident in primary rat hepatocytes (PRH) at the high concentration, while efficient biotransformation mediated by CYP3A4 and CYP3A5 was determined in primary human hepatocytes (PHH) and HepaRG cells. The lower biotransformation in PRH is in accordance with observation made in vivo with the rat being a poor model for CYP3A biotransformation. Further, inter-assay variability was noticed in PHH caused by biological variability in CYP3A4 and CYP3A5 activity in human donors. The inter-assay variability observed for PRH and HepaRG cells was a result of differences between vehicles regarding their cyclosporine A content. Cyclosporine A biotransformation was more prominent in HepaRG cells due to stable and high CYP3A4 and CYP3A5 activity. In addition, in vitro clearances were calculated and scaled to in vivo. All scaled in vitro clearances were overestimated (PRH: 10-fold, PHH: 2-fold, HepaRG cells: 2-fold). These results should be proven by physiologically-based pharmacokinetic modeling and additional experiments, in order to verify that these overestimations are constant for each system and subsequently can be diminished by implementation of further scaling factors. Brain cell cultures, primary neuronal culture of mouse cortex cells and primary aggregating rat brain cells, revealed fast achieved steady state levels of cyclosporine A. This indicates a chemical distribution of cyclosporine A between the aqueous and organic phases and only minor involvement of biological processes such as active transport and biotransformation. Hence, cyclosporine A uptake into cells is presumably transport mediated, supported by findings of transporter experiments performed on a parallel artificial membrane and Caco-2 cells. Plastic adsorption of cyclosporine A was significant, but different for each model, and should be considered by physiologically based pharmacokinetic modeling. Kinetics of adefovir dipivoxil highlights the limits of in vitro approaches. Active transporters are required for adefovir uptake, but were not functional in RPTECT/TERT1. Therefore, adefovir uptake was limited to passive diffusion of adefovir dipivoxil, which itself degrades time-dependently under culture conditions. Cisplatinum kinetics, studied in RPTEC/TERT1 cells, indicated intracellular enrichment of platinum, while significant bioaccumulation was not noted. This could be due to cisplatinum not reaching steady state levels within 14 days repeated exposure. As shown in vivo, active transport occurred from the basolateral to apical side, but with lower velocity. Hence, obtained data need to be modeled to estimate cellular processes, which can be scaled and compared to in vivo. Repeated daily exposure to two different drug concentrations makes it possible to account for bioaccumulation at toxic concentrations or biotransformation/extrusion at non-toxic concentrations. Potential errors leading to misinterpretation of data were reduced by analyses of the vehicles as the applied drug concentrations do not necessarily correspond to the nominal concentrations. Finally, analyses of separate compartments (medium, cells, plastic) give insights into a compound's distribution, reduce misprediction of cellular processes, e.g. biotransformation, and help to interpret kinetic data. On the other hand, the limits of in vitro approaches have also been pointed out. For correct extrapolation to in vivo, it is essential that the studied in vitro system exhibits the functionality of proteins, which play a key role in the specific drug induced toxicity. Considering the benefits and limitations, it is worth to validate this long-term treatment experimental set-up and expand it on co-culture systems and on organs-on-chips with regard to alternative toxicity testing strategies for repeated dose toxicity studies.},
  subject      = {Zellkultur},
  language  = {en}
}
@article{BerendzenWeisteWankeetal.2012,
  author    = {Berendzen, Kenneth W. and Weiste, Christoph and Wanke, Dierk and Kilian, Joachim and Harter, Klaus and Dr{\"o}ge-Laser, Wolfgang},
  title     = {Bioinformatic cis-element analyses performed in Arabidopsis and rice disclose bZIP- and MYB-related binding sites as potential AuxRE-coupling elements in auxin-mediated transcription},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75138},
  year      = {2012},
  abstract  = {Background: In higher plants, a diverse array of developmental and growth-related processes is regulated by the plant hormone auxin. Recent publications have proposed that besides the well-characterized Auxin Response Factors (ARFs) that bind Auxin Response Elements (AuxREs), also members of the bZIP- and MYB-transcription factor (TF) families participate in transcriptional control of auxin-regulated genes via bZIP Response Elements (ZREs) or Myb Response Elements (MREs), respectively. Results: Applying a novel bioinformatic algorithm, we demonstrate on a genome-wide scale that singular motifs or composite modules of AuxREs, ZREs, MREs but also of MYC2 related elements are significantly enriched in promoters of auxin-inducible genes. Despite considerable, species-specific differences in the genome structure in terms of the GC content, this enrichment is generally conserved in dicot (Arabidopsis thaliana) and monocot (Oryza sativa) model plants. Moreover, an enrichment of defined composite modules has been observed in selected auxin-related gene families. Consistently, a bipartite module, which encompasses a bZIP-associated G-box Related Element (GRE) and an AuxRE motif, has been found to be highly enriched. Making use of transient reporter studies in protoplasts, these findings were experimentally confirmed, demonstrating that GREs functionally interact with AuxREs in regulating auxin-mediated transcription. Conclusions: Using genome-wide bioinformatic analyses, evolutionary conserved motifs have been defined which potentially function as AuxRE-dependent coupling elements to establish auxin-specific expression patterns. Based on these findings, experimental approaches can be designed to broaden our understanding of combinatorial, auxin-controlled gene regulation.},
  subject      = {Arabidopsis},
  language  = {en}
}
@article{BergerEllersiekKinzeltetal.1993,
  author    = {Berger, Susanne and Ellersiek, Ulrike and Kinzelt, Dagmar and Steinm{\"u}ller, Klaus},
  title     = {Immunopurification of a subcomplex of the NAD(P)H-plastoquinone-oxidoreductase from the cyanobacterium Synechocystis sp. PCC6803},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31249},
  year      = {1993},
  abstract  = {An antibody against the NDH-K subunit of the NAD(P)H-dehydrogenase from the cyanobacterium Synechocystis sp. PCC6803 was used to isolate a subcomplex ofthe enzyme from Triton X-lOO solubilized total membranes by immunoaffinity chromatography. The isolated subcomplex consisted of seven major polypeptides with molecular masses of 43, 27, 24, 21, 18, 14 and 7 kDa. The amino-terminal amino acid sequences of the polypeptides were determined. By comparing the sequences with the amino acid sequences deduced from DNA. three proteins were identified as NDH-H (43 kDa). NDH-K (27 kDa) and NDH-J (24 kDa). A fourth subunit (NDH-J, 21 kDa) was identified by Western blot analysis with an NDH-J antibody.},
  language  = {en}
}
@article{BergerEllersiekSteinmueller1991,
  author    = {Berger, Susanne and Ellersiek, Ulrike and Steinm{\"u}ller, Klaus},
  title     = {Cyanobacteria contain a mitochrondrial complex I-homologous NADH-dehydrogenase},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31223},
  year      = {1991},
  abstract  = {Thylakoid and cytoplasmic membranes of the cyanobacterium Syncchocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhKand ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADHubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria, The NADH-dehydrogenase can be solubilized with the detergent /-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex.},
  language  = {en}
}
@article{BergerEllersiekWesthoffetal.1993,
  author    = {Berger, Susanne and Ellersiek, Ulrike and Westhoff, Peter and Steinm{\"u}ller, Klaus},
  title     = {Studies on the expression of NDH-H, a subunit of the NAD(P)H-plastoquinone-oxidoreductase of higher-plant chloroplasts},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31283},
  year      = {1993},
  abstract  = {The plastid genomes of higher plants contain eleven reading frames (ndhA-K) that are homologous to genes encoding subunits of the mitochondrial NADH-ubiquinone-oxidoreductase (complex I). The carboxyterminal end of the NDH-H subunit from rice (Oryza sativa L.) was expressed as a fusion protein in Escherichia coli and antibodies against the fusion protein were generated in rabbits. The antibody was used to study the expression of NDH-H, and the following results were obtained: (i) NDH-H is expressed in mono- and dicotyledonous plants, (ii) NDH-H is localized on the stroma lamellae of the thylakoid membrane and (iii) NDH-H is expressed in etioplasts. Together with the finding that two other ndh genes (ndhI and ndhK) are expressed in plastids, these results point to the existence of an NAD(P)H-plastoquinone-oxidoreductase on the thylakoid membrane. The possible function of the enzyme in plastids is discussed and it is suggested that it works in balancing the ATP/ADP and the NADPH/NADP ratios during changing external (i.e. light) or internal (i.e. ATP and NADPH demands of biosynthetic pathways of the plastid) conditions.},
  language  = {en}
}
@phdthesis{BergmannBueno2021,
  author    = {Bergmann Bueno, Amauri},
  title     = {Ecophysiological adaptations of cuticular water permeability of plants to hot arid biomes},
  doi       = {10.25972/OPUS-16783},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167832},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Arid environments cover almost one-third of the land over the world. Plant life in hot arid regions is prone to the water shortage and associated high temperatures. Drought-stressed plants close the stomata to reduce water loss. Under such conditions, the remaining water loss exclusively happens across the plant cuticle. The cuticular water permeability equals the minimum and inevitable water loss from the epidermal cells to the atmosphere under maximally stomatal closure. Thus, low cuticular water permeability is primordial for plant survival and viability under limited water source. The assumption that non-succulent xerophytes retard water loss due to the secretion of a heavier cuticle is often found in the literature. Intuitively, this seems to be plausible, but few studies have been conducted to evaluate the cuticular permeability of xerophilous plants. In chapter one, we investigated whether the cuticular permeability of Quercus coccifera L. grown in the aridest Mediterranean-subtype climate is indeed lower than that of individuals grown under temperate climate conditions. Also, the cuticular wax chemical compositions of plants grown in both habitats were qualitatively and quantitatively analysed by gas-chromatography. In few words, our findings showed that although the cuticular wax deposition increased in plants under Mediterranean climate, the cuticular permeability remained unaltered, regardless of habitat. The associated high temperatures in arid regions can drastically increase the cuticular water permeability. Thereby, the thermal stability of the cuticular transpirational barrier is decisive for safeguarding non-succulent xerophytes against desiccation. The successful adaptation of plants to hot deserts might be based on finding different solutions to cope with water and heat stresses. Water-saver plants close the stomata before the leaf water potential drastically changes in order to prevent damage, whereas water-spender plants reduce the leaf water potential by opening the stomata, which allow them to extract water from the deep soil to compensate the high water loss by stomatal transpiration. In chapter two, we compare the thermal stability of the cuticular transpiration barrier of the desert water-saver Phoenix dactylifera L. and the water-spender Citrullus colocynthis (L.) Schrad. In short, the temperature-dependent increase of the cuticular permeability of P. dactylifera was linear over the whole temperature range (25-50°C), while that of C. colocynthis was biphasic with a steep increase at temperatures ≥ 40°C. This drastic increase of cuticular permeability indicates a thermally induced breakdown of the C. colocynthis cuticular transpiration barrier, which does not occur in P. dactylifera. We further discussed how the specific chemical composition of the cutin and cuticular waxes might contribute to the pronounced thermal resistance of the P. dactylifera cuticular transpiration barrier. A multitude of morpho and physiological modifications, including photosynthetic thermal tolerance and traits related to water balance, led to the successful plant colonisation of hot arid regions over the globe. High evaporative demand and elevated temperatures very often go along together, thereby constraining the plant life in arid environments. In chapter 3, we surveyed cuticular permeability, leaf thermal tolerance, and cuticular wax chemical composition of 14 non-succulent plant species native from some of the hottest and driest biomes in South-America, Europe, and Asia. Our findings showed that xerophilous flowering plants present high variability for cuticular permeability and leaf thermal tolerance, but both physiological features could not be associated with the species original habitat. We also provide substantial evidence that non-succulent xerophytes with more efficient cuticular transpirational barrier have higher leaf thermal tolerance, which might indicate a potential coevolution of these features in hot arid biomes. We further discussed the efficiency of the cuticular transpiration barrier in function to the cuticular wax chemical composition in the general discussion section.},
  subject      = {Plant cuticle},
  language  = {en}
}
@article{BhavsarSinghSharmaetal.2016,
  author    = {Bhavsar, Shefalee K. and Singh, Yogesh and Sharma, Piyush and Khairnar, Vishal and Hosseinzadeh, Zohreh and Zhang, Shaqiu and Palmada, Monica and Sabolic, Ivan and Koepsell, Hermann and Lang, Karl S. and Lang, Philipp A. and Lang, Florian},
  title     = {Expression of JAK3 Sensitive Na\(^+\) Coupled Glucose Carrier SGLT1 in Activated Cytotoxic T Lymphocytes},
  series = {Cellular Physiology and Biochemistry},
  volume    = {39},
  journal   = {Cellular Physiology and Biochemistry},
  number    = {3},
  doi       = {10.1159/000447827},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164900},
  pages     = {1209-1228},
  year      = {2016},
  abstract  = {Background: Similar to tumor cells, activated T-lymphocytes generate ATP mainly by glycolytic degradation of glucose. Lymphocyte glucose uptake involves non-concentrative glucose carriers of the GLUT family. In contrast to GLUT isoforms, Na+-coupled glucose-carrier SGLT1 accumulates glucose against glucose gradients and is effective at low extracellular glucose concentrations. The present study explored expression and regulation of SGLT1 in activated murine splenic cytotoxic T cells (CTLs) and human Jurkat T cells. Methods: FACS analysis, immunofluorescence, confocal microscopy, chemiluminescence and Western blotting were employed to estimate SGLT1 expression, function and regulation in lymphocytes, as well as dual electrode voltage clamp in SGLT1 ± JAK3 expressing Xenopus oocytes to quantify the effect of janus kinase3 (JAK3) on SGLT1 function. Results: SGLT1 is expressed in murine CTLs and also in human Jurkat T cells. 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose uptake was significantly decreased by SGLT1-blocker phloridzin (0.2 mM) and by pharmacological inhibition of JAK3 with WHI-P131 (156 µM), WHI-P154 (11.2 µM) and JAK3 inhibitor VI (0.5 µM). Electrogenic glucose transport (Iglucose) in Xenopus oocytes expressing human SGLT1 was increased by additional expression of human wild type JAK3, active A568VJAK3 but not inactive K851AJAK3. Coexpression of JAK3 enhanced the maximal transport rate without significantly modifying affinity of the carrier. Iglucose in SGLT1+JAK3 expressing oocytes was significantly decreased by WHI-P154 (11.2 µM). JAK3 increased the SGLT1 protein abundance in the cell membrane. Inhibition of carrier insertion by brefeldin A (5 µM) in SGLT1+JAK3 expressing oocytes resulted in a decline of Iglucose, which was similar in presence and absence of JAK3. Conclusions: SGLT1 is expressed in murine cytotoxic T cells and human Jurkat T cells and significantly contributes to glucose uptake in those cells post activation. JAK3 up-regulates SGLT1 activity by increasing the carrier protein abundance in the cell membrane, an effect enforcing cellular glucose uptake into activated lymphocytes and thus contributing to the immune response.},
  language  = {en}
}
@phdthesis{Bieber2013,
  author    = {Bieber, Michael},
  title     = {Funktionelle Charakterisierung zweier Lipid Transfer Proteine in der Arabidopsis thaliana Pathogenantwort},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97682},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Die Multigenfamilie der Lipid Transfer Proteine (LTP) stellt eine Gruppe von kleinen Proteinen dar, welche in allen h{\"o}heren Landpflanzen vorkommen. In der Modellpflanze Arabidopsis thaliana werden 92 Proteine zur Klasse der LTPs gez{\"a}hlt. Die Benennung der Proteinfamilie basiert auf dem beobachteten in vitro Transfer von Lipiden zwischen zwei Membranen. Alle LTPs weisen ein konserviertes, 8 Cysteine beinhaltendes Motiv und eine hydrophobe Tasche auf, welche f{\"u}r die Bindung hydrophober Molek{\"u}le verantwortlich ist. Aufgrund ihrer Signalsequenz werden LTPs {\"u}ber den sekretorischen Weg in den extrazellul{\"a}ren Raum geschleust. F{\"u}r einige pflanzliche LTPs konnte eine derartige Sekretion bereits nachgewiesen werden. F{\"u}r andere LTPs wird eine Funktion in der Kutinbildung, der Embryogenese oder der pflanzlichen Immunantwort gegen Phytopathogene postuliert. Letzteres wurde f{\"u}r DIR1 (DEFECTIVE IN INDUCED RESISTANCE 1) und AZI1 (AZELAIC ACID INDUCED 1) nachgewiesen, w{\"a}hrend von LTPIV.4 (At4g55450) nur bekannt ist, dass die Expression spezifisch in Antwort auf Pathogene induziert ist. Aus diesem Grund wurde in der vorliegenden Arbeit die Funktion von LTPIV.4 und AZI1 in Bezug auf die pflanzliche Pathogenantwort in Arabidopsis thaliana untersucht. Anhand von GFP-Fusionsproteinen konnte f{\"u}r LTPIV.4 und AZI1 eine Endoplasmatische Retikulum-Lokalisierung detektiert werden. Auch eine gewebespezifische Promotoraktivit{\"a}t von LTPIV.4 an den Leitgeweben und in jungen sich entwickelnden Bl{\"a}ttern konnte identifiziert werden. Diese Erkenntnisse lassen darauf schließen, dass LTPIV.4 m{\"o}glicherweise an der Signaltransduktion am/im Leitgewebe mitverantwortlich ist. Im Fokus dieser Arbeit stand die spezifische Einordnung von LTPIV.4 in der Ausbildung der lokalen bzw. systemischen Immunantwort von Arabidopsis thaliana. Anhand einer Infektion von Wildtyppflanzen und LTPIV.4 Mutanten mit zwei verschiedenen Pseudomonasst{\"a}mmen konnte eine LTPIV.4-abh{\"a}ngige Steigerung der pflanzlichen Resistenz gegen die biotrophen Bakterien nachgewiesen werden. In der Resistenz gegen den nekrotrophen Pilz Sclerotinia hingegen zeigte sich keine LTPIV.4 Abh{\"a}ngigkeit. Da die Hormone Salicyls{\"a}ure (SA) und Jasmons{\"a}ure (JA) in der Ausbildung der pflanzlichen Abwehr gegen verschiedene Pathogene wichtig sind, wurden die Hormonlevel von SA und JA in ltpIV.4, 35S::LTPIV.4 sowie in Wildtyppflanzen analysiert. Die untersuchten Phytohormongehalte zeigten eine LTPIV.4 unabh{\"a}ngige, schnelle Akkumulation von SA nach der Infektion mit virulenten (vir) Pseudomonas syringae pv. maculicola (Psm) und eine sp{\"a}tere Erh{\"o}hung der JA-Gehalte. Es konnte somit kein regulatorischer Effekt von LTPIV.4 auf die SA- sowie die JA-Gehalte detektiert werden. Die Expression von SAG13 (SENESCENCE-ASSOCIATED GENE 13) und OXI1 (OXIDATIVE SIGNAL-INDUCIBLE 1), welche eine Funktion im programmierten Zelltod (PCD) haben beziehungsweise durch oxidativen Stress induziert werden, war hingegen erh{\"o}ht in konstitutiv LTPIV.4 exprimierenden Pflanzen, verglichen mit dem Wildtyp von LTPIV.4. Als ein weiterer Ansatzpunkt f{\"u}r die funktionelle Charakterisierung von LTPIV.4 wurde die in vitro Identifizierung m{\"o}glicher Substrate mittels Lipid-Protein-Interaktionsanalysen, sowie einer unspezifischen Metabolomanalyse herangezogen. Bei den Interaktionsanalysen konnten Phosphatids{\"a}uren (PA), Phosphatidylglycerine (PG), Monogalactosyldiacylglycerole (MGDG) und auch Digalactosyldiacylglycerole (DGDG) als Interaktionspartner von LTPIV.4 identifiziert werden. Die Metabolomanalyse zeigte einen quantitativen Unterschied zwischen Wildtyp/35S::LTPIV.4 und ltpIV.4 bei einigen MGDG, DGDG und PG Spezies. Aus den in dieser Arbeit gewonnen Daten l{\"a}sst sich somit schließen, dass LTPIV.4 nach Pathogen/Schaden-assoziierte molekulare Muster- (PAMP/ DAMP-) Erkennung, z.B. von Psm, SA-abh{\"a}ngig vermehrt gebildet wird. Da die konstitutive Expression von LTPIV.4 sowohl zu erh{\"o}hter OXI1 und SAG13 Expression als auch zu erh{\"o}hter Resistenz gegen{\"u}ber Psm f{\"u}hrt, l{\"a}sst sich ein Modell aufstellen, in dem LTPIV.4 als positiver Regulator des PCD die Pathogenresistenz von Arabidopsis erh{\"o}ht. Der zugrunde liegende Mechanismus ist unbekannt. Die Bindung von PAs, PGs, MGDGs und DGDGs an LTPIV.4 in vitro k{\"o}nnte darauf hindeuten, dass auch in vivo hydrophobe Molek{\"u}le gebunden und m{\"o}glicherweise transportiert werden und dies ein Teil der Pathogenantwort ist. Es w{\"a}re z.B. denkbar, dass eine m{\"o}gliche Translokation von LTPIV.4 {\"u}ber das ER in das Zytoplasma oder den apoplastischen Raum erfolgt. Dort interagiert LTPIV.4 mit durch ROS gebildeten, oxidierten Lipiden oder DAMPs und l{\"o}st entweder symplastisch durch eine Interaktion in der Infizierten Zelle oder in intakten Nachbarzellen durch eine weitere Signaltransduktionskaskade den PCD sowie eine erh{\"o}hte ROS Bildung aus, oder das LTP interagiert spezifisch mit oxidierten Lipiden oder DAMPs von abgestorbenen Nachbarzellen, und l{\"o}st eine intrazellul{\"a}re Signalkaskade mit Initiierung des PCD sowie erh{\"o}hter ROS-Bildung aus. AZI1 wurde als zweites LTP in dieser Arbeit einbezogen. Ausgehend von der Beobachtung, dass die konstitutive Expression von AZI1 die Resistenz gegen das nekrotrophe Pathogene Botrytis cinerea erh{\"o}ht, sollte in der vorliegenden Arbeit detailiert untersucht werden, ob AZI1 eine Rolle in der Resistenz gegen das nekrotrophe Pathogen Sclerotinia sclerotiorum spielt. Die azi1-1 Mutante zeigte hierbei jedoch eine erh{\"o}hte Resistenz gegen den nekrotrophen Pilz Sclerotinia sclerotiorum. Da bisher keine Unterschiede in der Genexpression von spezifischen Markergenen in WT und azi1-1 Pflanzen nach Sklerotiniainfektion festgestellt werden konnte und es auch f{\"u}r LTPs bekannt ist, dass sie eine Rolle in der Kutikulasynthese spielen, w{\"a}re eine Hypothese, dass die unterschiedlichen Infektionsph{\"a}notypen mit Sclerotinia und Botrytis auf eine strukturelle Ver{\"a}nderung der Kutikulabeschaffenheit zur{\"u}ckzuf{\"u}hren sind. Weiterhin konnte f{\"u}r AZI1 eine m{\"o}gliche Rolle in der Verwundungsantwort detektiert werden, da sowohl die AZI1 Genexpression, als auch die erhaltenen basal signifikant erh{\"o}hten 12-oxo-Phytodiens{\"a}ure (OPDA)-Gehalte auf eine negativ regulatorische Rolle von AZI1 in der Verwundungs-abh{\"a}ngigen JA-Signaltransduktion hindeuten.},
  subject      = {Lipid-Carrier-Proteine},
  language  = {de}
}
@phdthesis{Biela2000,
  author    = {Biela, Alexander},
  title     = {Molekulare und funktionelle Charakterisierung von pflanzlichen Aquaporinen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-3207},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2000},
  abstract  = {In der vorliegenden Arbeit wurden pflanzliche Aquaporine aus Nicotiana tabacum und Samanea saman mit molekularbiologischen Methoden analysiert und durch heterologe Expression in Oozyten von Xenopus laevis funktionell charakterisiert. Das aus Tabak isolierte Aquaporin NtAQP1 wird am h{\"o}chsten in Wurzeln exprimiert, ist trotz vorhandener Cysteine nicht quecksilbersensitiv und permeabel f{\"u}r Glycerin und Harnstoff. Sowohl eine Ionenleitf{\"a}higkeit, als auch eine Regulation auf Proteinebene konnten im Oozytensystem nicht nachgewiesen werden. Die Leguminose Samanea saman bewegt im Tag-/Nachtrhythmus ihre Fiederbl{\"a}tter und -stengel. Dieses wird durch Variieren des Turgors im Flexorgewebe von Pulvini realisiert. W{\"a}hrend SsAQP1 in seinen Charakteristika mit NtAQP1 {\"u}bereinstimmt, ist SsAQP2 quecksilbersensitiv und hoch selektiv f{\"u}r Wasser. Der f{\"u}r SsAQP2 ermittelte Permeabilit{\"a}tskoeffizient war um den Faktor 10 h{\"o}her als der von SsAQP1. Northern Experimente zeigten, dass SsAQP2 ausschließlich im Flexorgewebe exprimiert wird. Die Expression ist zum Zeitpunkt der Streckungsbewegung des Pulvinus um 7 Uhr am st{\"a}rksten. Dagegen wurde SsAQP1 zu allen untersuchten Zeitpunkten nur schwach in Pulvini exprimiert.},
  subject      = {Tabak},
  language  = {de}
}
@phdthesis{Blachutzik2012,
  author    = {Blachutzik, J{\"o}rg O.},
  title     = {Visualisierung von Plasmamembran-Dom{\"a}nen in Arabidopsis thaliana},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71925},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Unter Verwendung fluoreszenzmarkierter Remorine der taxonomischen Gruppe 1b wurden Nanodom{\"a}nen in Arabidopsis Plasmamembranen (PM) unter Verwendung hoch aufl{\"o}sender Laser Scanning-Systeme sichtbar gemacht. In diesen kompartimentierten Membranbereichen lagerten sich Sterol-abh{\"a}ngige Remorine aus verschiedenen Pflanzen-familien zusammen und zeigten dort Kolokalisation. Dies wurde statistisch belegt durch hohe Pearson und Spearman Korrelationskoeffizienten. Remorine konnten schließlich als pflanzliche Markerproteine f{\"u}r kompartimentierte Membranbereiche etabliert werden. Die Nanodom{\"a}nen zeigten zu keinem Zeitpunkt laterale Bewegungen in der PM und scheinen sowohl von zytoskelett{\"a}ren Strukturen als auch von Komponenten der Zellwand stabilisiert zu werden. M{\"o}glicherweise spielen transmembrane Tetraspanine sowie GPI-verankerte SKU5-Proteine eine Rolle bei der stabilen Verankerung. F{\"u}r zwei native Arabidopsis Remorine wurden posttranslationale Modifikationsstellen aufgedeckt, die der Anheftung dieser hydrophilen Proteine an die PM dienen. Weiterhin scheinen gleichartige Remorine miteinander zu interagieren. Beispielsweise waren im Zytosol lokalisierte Remorin-Mutanten bei einer gleichzeitigen Expression der entsprechenden Voll{\"a}ngenproteine erneut an der PM zu finden. F{\"u}r die Remorine wurde postuliert, dass sie mit anderen Proteinen interagieren und dabei makromolekulare Strukturen ausbilden. Den Remorinen k{\"o}nnte daher eine Aufgabe bei der molekularen Organisation pflanzlicher Membrandom{\"a}nen zukommen, indem sie ein filamentartiges Netzwerk innerhalb distinkter Dom{\"a}nen ausbilden, das m{\"o}glicherweise zur Stabilit{\"a}t und Aufrechterhaltung dieser spezialisierten Bereiche beitr{\"a}gt. Unter Einbeziehung der STED-Mikroskopie wurde eine empirische Gr{\"o}ßenverteilung von 97±4nm Durchmesser f{\"u}r PM-st{\"a}ndige Dom{\"a}nen in Arabidopsis ermittelt. Hinsichtlich der physiologischen Relevanz konnte gezeigt werden, dass die Dom{\"a}nen eine Rolle bei der ABA-vermittelten, kalziumabh{\"a}ngigen Regulation des Anionenkanals SLAH3 einnehmen. SLAH3 wird durch kalziumabh{\"a}ngige Kinasen aus der CDPK-Familie aktiviert, im Speziellen durch CPK21 und CPK23. Beide Kinasen werden durch die ABA-sensitiven Phosphatasen ABI1 und ABI2 reguliert. Die spezifisch stattfindenden Interaktionen zwischen SLAH3 und CPK21, sowie zwischen CPK21 und ABI1 waren auf Nanodom{\"a}nen beschr{\"a}nkt und wurden durch die Methodik der bimolekularen Fluoreszenzkomplementation erstmals in planta nachgewiesen, mit Remorinen der taxonomischen Gruppe 1b als etablierte Markerproteine f{\"u}r Membrandom{\"a}nen.},
  subject      = {Plasmamembran},
  language  = {de}
}
@article{BlachutzikDemirKreuzeretal.2012,
  author    = {Blachutzik, J{\"o}rg O. and Demir, Faith and Kreuzer, Ines and Hedrich, Rainer and Harms, Gregory S.},
  title     = {Methods of staining and visualization of sphingolipid enriched and non-enriched plasma membrane regions of Arabidopsis thaliana with fluorescent dyes and lipid analogues},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75433},
  year      = {2012},
  abstract  = {Background: Sterols and Sphingolipids form lipid clusters in the plasma membranes of cell types throughout the animal and plant kingdoms. These lipid domains provide a medium for protein signaling complexes at the plasma membrane and are also observed to be principal regions of membrane contact at the inception of infection. We visualized different specific fluorescent lipophilic stains of the both sphingolipid enriched and non-sphingolipid enriched regions in the plasma membranes of live protoplasts of Arabidopsis thaliana. Results: Lipid staining protocols for several fluorescent lipid analogues in plants are presented. The most emphasis was placed on successful protocols for the single and dual staining of sphingolipid enriched regions and exclusion of sphingolipid enriched regions on the plasma membrane of Arabidopsis thaliana protoplasts. A secondary focus was placed to ensure that these staining protocols presented still maintain cell viability. Furthermore, the protocols were successfully tested with the spectrally sensitive dye Laurdan. Conclusion: Almost all existing staining procedures of the plasma membrane with fluorescent lipid analogues are specified for animal cells and tissues. In order to develop lipid staining protocols for plants, procedures were established with critical steps for the plasma membrane staining of Arabidopsis leaf tissue and protoplasts. The success of the plasma membrane staining protocols was additionally verified by measurements of lipid dynamics by the fluorescence recovery after photobleaching technique and by the observation of new phenomena such as time dependent lipid polarization events in living protoplasts, for which a putative physiological relevance is suggested.},
  subject      = {Arabidopsis thaliana},
  language  = {de}
}
@phdthesis{Bonfig2008,
  author    = {Bonfig, Katharina Barbara},
  title     = {Untersuchungen zur Rolle des Kohlenhydratmetabolismus w{\"a}hrend Pflanze-Pathogen-Interaktionen und der Keimlingsentwicklung},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32488},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Invertasen sind Schl{\"u}sselenzyme in der Kohlenhydratverteilung und haben m{\"o}glicherweise auch w{\"a}hrend einer Pathogeninfektion eine zentrale Bedeutung. In vorliegender Arbeit wurde zun{\"a}chst die Regulation verschiedener Stoffwechselwege in Arabidopsis thaliana nach Infektionen mit einem virulenten oder avirulenten Stamm von Pseudomonas syringae untersucht. Mit Hilfe der Chlorophyllfluoreszenz-Bildgebung konnten r{\"a}umliche und zeitliche Ver{\"a}nderungen der Photosynthese verfolgt werden. Verschiedene Parameter waren unterschiedlich reguliert. In beiden Interaktionen waren Effekte nur lokal um die Infektionsstellen erkennbar und qualitativ {\"a}hnlich. Unterschiede waren im zeitlichen Eintreten und Verlauf sichtbar. Die Methode schien geeignet f{\"u}r die sensitive, nicht-invasive Pathogenfr{\"u}herkennung vor dem Auftreten sichtbarer Symptome. Die Regulation verschiedener Gene innerhalb von Source-Sink-{\"U}berg{\"a}ngen und die Aktivit{\"a}t von Invertasen war in den beiden Interaktionen qualitativ unterschiedlich. Die Infektion mit virulenten Bakterien resultierte in einer Repression photosynthetischer Gene. Die Aktivit{\"a}t vakuol{\"a}rer Invertasen stieg vor{\"u}bergehend nach Infektion mit virulenten Bakterien an, w{\"a}hrend sie nach Infektion mit avirulenten Bakterien sank. Die Aktivit{\"a}t extrazellul{\"a}rer Invertasen war in beiden Interaktionen reprimiert. Die erfolgreiche Generierung verschiedener Bakterienst{\"a}mme von P. syringae, die das gr{\"u}n fluoreszierende Protein exprimieren, kann bei der weiteren Charakterisierung von Pflanze-Pathogen-Interaktionen helfen. Die Regulation von Invertasen erfolgt auf transkriptioneller und posttranslationaler Ebene. Um die Funktion von Invertasen in Pflanze-Pathogen-Interaktionen zu verstehen, wurde zun{\"a}chst die Regulation von Invertasen durch endogene proteinogene Invertaseinhibitoren untersucht. In {\"U}bereinstimmung mit in silico Expressionsdaten konnte durch Untersuchung von Reportergenlinien und in Northern Blot Analysen eine starke Expression von Invertaseinhibitoren in Bl{\"a}ttern von A. thaliana festgestellt werden. Nach Applikation biotischer und abiotischer Stressfaktoren wurde diese Expression nahezu vollst{\"a}ndig reprimiert. Die indirekte Bestimmung der Invertaseinhibitoraktivit{\"a}t durch Messung der Invertaseaktivit{\"a}t in Mischextrakten zeigte, dass diese nach einer Pathogeninfektion vollst{\"a}ndig reprimiert war. In funktionellen Ans{\"a}tzen wurden transgene Pflanzen generiert, die Invertaseinhibitoren unter Kontrolle induzierbarer Promotoren exprimieren. Die Induktion der Invertaseinhibitorexpression {\"a}nderte die Sensitivit{\"a}t gegen{\"u}ber verschiedenen Pathogenen nicht signifikant. In einem pharmakologischen Ansatz wurde der chemische Inhibitor Acarbose zur Hemmung der Invertaseaktivit{\"a}t in A. thaliana verwendet. Eine Behandlung von Bl{\"a}ttern bei gleichzeitiger Infektion mit Bakterien verursachte eine erh{\"o}hte Sensitivit{\"a}t der Pflanzen gegen{\"u}ber der Infektion, eine st{\"a}rkere Repression verschiedener Chlorophyllfluoreszenzparameter sowie ein erh{\"o}htes Bakterienwachstum im Vergleich zu einer Infektion mit den Bakterien allein. Keine Effekte wurden auf transkriptioneller Ebene bei der Untersuchung von Genen verschiedener Stoffwechselwege gefunden. Die Invertaseaktivit{\"a}t nach zus{\"a}tzlicher Behandlung mit Acarbose war tendenziell niedriger als die Aktivit{\"a}t nach einer Pathogeninfektion alleine. Acarbose erh{\"o}hte die Spiegel an Salicyls{\"a}ure unabh{\"a}ngig von einer Pathogeninfektion. Da das Bakterienwachstum in Mutanten des Salicyls{\"a}ure-vermittelten Abwehrweges bei zus{\"a}tzlicher Behandlung mit Acarbose ebenfalls erh{\"o}ht war, kann eine Beteiligung dieses Abwehrweges am Acarboseeffekt bisher ausgeschlossen werden. Invertasen sind neben ihrer Beteiligung an der Abwehr f{\"u}r die Regulation von Entwicklungsprozessen wichtig. In einem funktionellen Ansatz mit Pflanzen, die Invertaseinhibitoren induzierbar produzieren, wurde die Funktion von Invertasen getestet. Zur Generierung spezifischer Effekte wurden die Inhibitoren unter Kontrolle synthetischer Promotoren in A. thaliana exprimiert. Unerwarteterweise war das Wachstum putativ transgener Keimlinge jedoch im 4-Blatt-Stadium arretiert. Eine Analyse der Aktivit{\"a}t der ß-Glucuronidase in den entsprechenden Reporterlinien zeigte eine Korrelation zwischen der Wachstumsarretierung und einer hohen Aktivit{\"a}t dieser Promotoren unter verschiedenen in vitro Bedingungen. Dieser negative Effekt der Invertaseinhibition auf das Keimlingswachstum wurde in transgenen Tabakpflanzen bekr{\"a}ftigt, die Invertaseinhibitoren unter Kontrolle eines Tetracyclin-induzierbaren Promotors exprimierten. Eine erfolgreiche Induktion des Promotors resultierte in einer Reduktion des Frischgewichtes der Keimlinge. Mittels in silico Expressionsdaten und Northern Blot Analysen konnte f{\"u}r A. thaliana eine spezifische und starke Expression verschiedener Invertaseisoformen in Keimlingen nachgewiesen werden. Diese komplement{\"a}ren Ergebnisse zeigen die Notwendigkeit der Invertaseaktivit{\"a}t f{\"u}r eine normale Keimlingsentwicklung.},
  subject      = {Invertase},
  language  = {de}
}
@article{BoschertFrischBacketal.2016,
  author    = {Boschert, V. and Frisch, C. and Back, J. W. and van Pee,, K. and Weidauer, S. E. and Muth, E.-M. and Schmieder, P. and Beerbaum, M. and Knappik, A. and Timmerman, P. and Mueller, T. D.},
  title     = {The sclerostin-neutralizing antibody AbD09097 recognizes an epitope adjacent to sclerostin's binding site for the Wnt co-receptor LRP6},
  series = {Open Biology},
  volume    = {6},
  journal   = {Open Biology},
  doi       = {10.1098/rsob.160120},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177925},
  year      = {2016},
  abstract  = {The glycoprotein sclerostin has been identified as a negative regulator of bone growth. It exerts its function by interacting with the Wnt co-receptor LRP5/6, blocks the binding of Wnt factors and thereby inhibits Wnt signalling. Neutralizing anti-sclerostin antibodies are able to restore Wnt activity and enhance bone growth thereby presenting a new osteoanabolic therapy approach for diseases such as osteoporosis. We have generated various Fab antibodies against human and murine sclerostin using a phage display set-up. Biochemical analyses have identified one Fab developed against murine sclerostin, AbD09097 that efficiently neutralizes sclerostin's Wnt inhibitory activity. In vitro interaction analysis using sclerostin variants revealed that this neutralizing Fab binds to sclerostin's flexible second loop, which has been shown to harbour the LRP5/6 binding motif. Affinity maturation was then applied to AbD09097, providing a set of improved neutralizing Fab antibodies which particularly bind human sclerostin with enhanced affinity. Determining the crystal structure of AbD09097 provides first insights into how this antibody might recognize and neutralize sclerostin. Together with the structure-function relationship derived from affinity maturation these new data will foster the rational design of new and highly efficient anti-sclerostin antibodies for the therapy of bone loss diseases such as osteoporosis.},
  language  = {en}
}
@article{BoschertvanDintherWeidaueretal.2013,
  author    = {Boschert, Verena and van Dinther, Maarten and Weidauer, Stella and van Pee, Katharina and Muth, Eva-Maria and ten Dijke, Peter and Mueller, Thomas D.},
  title     = {Mutational Analysis of Sclerostin Shows Importance of the Flexible Loop and the Cystine-Knot for Wnt-Signaling Inhibition},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {11},
  doi       = {10.1371/journal.pone.0081710},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129862},
  pages     = {e81710},
  year      = {2013},
  abstract  = {The cystine-knot containing protein Sclerostin is an important negative regulator of bone growth and therefore represents a promising therapeutic target. It exerts its biological task by inhibiting the Wnt (wingless and int1) signaling pathway, which participates in bone formation by promoting the differentiation of mesenchymal stem cells to osteoblasts. The core structure of Sclerostin consists of three loops with the first and third loop (Finger 1 and Finger 2) forming a structured \(\beta\)-sheet and the second loop being unstructured and highly flexible. Biochemical data showed that the flexible loop is important for binding of Sclerostin to Wnt co-receptors of the low-density lipoprotein related-protein family (LRP), by interacting with the Wnt co-receptors LRP5 or -6 it inhibits Wnt signaling. To further examine the structural requirements for Wnt inhibition, we performed an extensive mutational study within all three loops of the Sclerostin core domain involving single and multiple mutations as well as truncation of important regions. By this approach we could confirm the importance of the second loop and especially of amino acids Asn92 and Ile94 for binding to LRP6. Based on a Sclerostin variant found in a Turkish family suffering from Sclerosteosis we generated a Sclerostin mutant with cysteines 84 and 142 exchanged thereby removing the third disulfide bond of the cystine-knot. This mutant binds to LRP6 with reduced binding affinity and also exhibits a strongly reduced inhibitory activity against Wnt1 thereby showing that also elements outside the flexible loop are important for inhibition of Wnt by Sclerostin. Additionally, we examined the effect of the mutations on the inhibition of two different Wnt proteins, Wnt3a and Wnt1. We could detect clear differences in the inhibition of these proteins, suggesting that the mechanism by which Sclerostin antagonizes Wnt1 and Wnt3a is fundamentally different.},
  language  = {en}
}
@article{BurgsdorfSlabyHandleyetal.2015,
  author    = {Burgsdorf, Ilia and Slaby, Beate M. and Handley, Kim M. and Haber, Markus and Blom, Jochen and Marshall, Christopher W. and Gilbert, Jack A. and Hentschel, Ute and Steindler, Laura},
  title     = {Lifestyle Evolution in Cyanobacterial Symbionts of Sponges},
  series = {mBio},
  volume    = {6},
  journal   = {mBio},
  number    = {3},
  doi       = {10.1128/mBio.00391-15},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143117},
  pages     = {e00391-15},
  year      = {2015},
  abstract  = {The "Candidatus Synechococcus spongiarum" group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99\%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a "Ca. Synechococcus spongiarum" group member was recently published, providing evidence of genome reduction by loss of genes involved in several nonessential functions. However, "Ca. Synechococcus spongiarum" includes a variety of clades that may differ widely in genomic repertoire and consequently in physiology and symbiotic function. Here, we present three additional draft genomes of "Ca. Synechococcus spongiarum," each from a different clade. By comparing all four symbiont genomes to those of free-living cyanobacteria, we revealed general adaptations to life inside sponges and specific adaptations of each phylotype. Symbiont genomes shared about half of their total number of coding genes. Common traits of "Ca. Synechococcus spongiarum" members were a high abundance of DNA modification and recombination genes and a reduction in genes involved in inorganic ion transport and metabolism, cell wall biogenesis, and signal transduction mechanisms. Moreover, these symbionts were characterized by a reduced number of antioxidant enzymes and low-weight peptides of photosystem II compared to their free-living relatives. Variability within the "Ca. Synechococcus spongiarum" group was mostly related to immune system features, potential for siderophore-mediated iron transport, and dependency on methionine from external sources. The common absence of genes involved in synthesis of residues, typical of the O antigen of free-living Synechococcus species, suggests a novel mechanism utilized by these symbionts to avoid sponge predation and phage attack. IMPORTANCE While the Synechococcus/Prochlorococcus-type cyanobacteria are widely distributed in the world's oceans, a subgroup has established its niche within marine sponge tissues. Recently, the first genome of sponge-associated cyanobacteria, " Candidatus Synechococcus spongiarum," was described. The sequencing of three representatives of different clades within this cyanobacterial group has enabled us to investigate intraspecies diversity, as well as to give a more comprehensive understanding of the common symbiotic features that adapt "Ca. Synechococcus spongiarum" to its life within the sponge host.},
  language  = {en}
}
@article{BoehmScherzerShabalaetal.2016,
  author    = {B{\"o}hm, J. and Scherzer, S. and Shabala, S. and Krol, E. and Neher, E. and Mueller, T. D. and Hedrich, R.},
  title     = {Venus flytrap HKT1-type channel provides for prey sodium uptake into carnivorous plant without conflicting with electrical excitability},
  series = {Molecular Plant},
  volume    = {9},
  journal   = {Molecular Plant},
  number    = {3},
  doi       = {10.1016/j.molp.2015.09.017},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189803},
  pages     = {428-436},
  year      = {2016},
  abstract  = {The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na\(^+\)- and K\(^+\)-permeable mutants function as ion channels rather than K\(^+\) transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na\(^+\)-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.},
  language  = {en}
}
@phdthesis{Boehm2015,
  author    = {B{\"o}hm, Jennifer},
  title     = {Die N{\"a}hrstoffresorption in den Fallen von Dionaea muscipula weist Parallelen zur N{\"a}hrsalzaufnahme in Wurzeln auf},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123958},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Die Venusfliegenfalle, Dionaea muscipula, weckte aufgrund ihrer karnivoren Lebensweise schon sehr fr{\"u}h das Interesse vieler Wissenschaftler. F{\"u}r karnivore Pflanzen, die auf N{\"a}hrstoff-armen B{\"o}den wachsen, spielen Insekten als Beute und somit als N{\"a}hrstofflieferant eine entscheidende Rolle. So k{\"o}nnen die Pflanzen durch die Verdauung der Beute mit wichtigen Makro- und Mikron{\"a}hrstoffen, wie Stickstoff, Phosphat, Kalium oder Natrium versorgt werden. Aus diesem Grund sollte im Rahmen meiner Arbeit ein besonderes Augenmerk auf die molekularen Mechanismen der Kationenaufnahme w{\"a}hrend der N{\"a}hrstoffresorption gerichtet werden. Insbesondere die aus dem Insekt stammenden N{\"a}hrstoffe Kalium und Natrium waren dabei von großem Interesse. Im Allgemeinen sind Kaliumionen f{\"u}r Pflanzen eine essentielle anorganische Substanz und von großer physiologischer Bedeutung f{\"u}r die Entwicklung, den Metabolismus, die Osmoregulation, das Membranpotential und viele zellul{\"a}re Prozesse. Analysen der Kaliumaufnahme an Wurzeln von Modellpflanzen wie Arabidopsis thaliana und Reis zeigten, dass die Aufnahme von K+ ein Zusammenspiel von hoch-affinen K+-Transportern der HAK5-Familie und nieder-affinen Kaliumkan{\"a}len (AKT1/AtKC1) erfordert, die in ein komplexes (De-)Phosphorylierungsnetzwerk eingebunden sind. In der vorliegenden Arbeit war es mir m{\"o}glich das Netzwerk zur Kaliumaufnahme in den Dr{\"u}sen der Venusfliegenfalle zu entschl{\"u}sseln. Es konnten Orthologe zum Kaliumtransporter HAK5 aus Arabidopsis (DmHAK5) und zum Kaliumkanal AKT1 (DmKT1) identifiziert und im heterologen Expressionssystem der Xenopus laevis Oozyten elektrophysiologisch charakterisiert werden. Dabei zeigte sich, das DmKT1 durch einen Ca2+-Sensor/Kinase-Komplex aus der CBL/CIPK-Familie phosphoryliert und somit aktiviert wird. Phylogenetische Analysen von DmKT1 best{\"a}tigten die Eingruppierung dieses Kaliumkanals in die Gruppe der pflanzlichen Shaker-Kaliumkan{\"a}le des AKT1-Typs. Die Transporteigenschaften zeigten zudem, dass DmKT1 bei hyperpolarisierenden Membranpotentialen aktiviert wird und einen K+-selektiven Einw{\"a}rtsstrom vermittelt. In Oozyten konnte eine Kaliumaufnahme bis zu einer externen Konzentration von ≥1 mM beobachtet werden. DmKT1 repr{\"a}sentiert also einen Kaliumkanal mit einer hohen Transportkapazit{\"a}t, der die nieder-affine Kaliumaufnahme in die Dr{\"u}senzellen der Venusfliegenfalle vermitteln kann. Unterhalb einer externen Kaliumkonzentration von 1 mM w{\"u}rde der anliegende elektrochemische Kaliumgradient einen Kaliumausstrom und somit einen Verlust von Kalium favorisieren. Hoch-affine K+/H+-Symporter k{\"o}nnen durch die Ausnutzung des Protonengradienten eine Kaliumaufnahme im mikromolaren Bereich gew{\"a}hrleisten. In Wurzelhaaren von Arabidopsis vermittelt der Transporter AtHAK5 die Kaliumaufnahme unter Kaliummangelbedingungen. DmHAK5, ein Ortholog zu AtHAK5, ist in Dionaea Dr{\"u}sen exprimiert und konnte zum ersten Mal im heterologen Expressionssystem der Xenopus Oozyten im Detail charakterisiert werden. Interessanterweise zeigte sich, dass DmHAK5 wie der K+-Kanal DmKT1 durch denselben CBL/CIPK-Komplex posttranslational reguliert und aktiviert wird. Die Transporteigenschaften von DmHAK5 wiesen auf einen Transporter mit einer breiten Substratspezifit{\"a}t hin, sodass sich DmHAK5 neben Kalium auch f{\"u}r Ammonium permeabel zeigte. Affinit{\"a}tsuntersuchungen von DmHAK5 zu seinem Substrat Kalium klassifizierten das Protein als einen hoch-affinen Kaliumtransporter, der im Symport mit Protonen die Kaliumaufnahme im mikromolaren Konzentrationsbereich vermitteln kann. Das Kaliumtransportmodul besteht also aus dem K+-selektiven Kanal DmKT1 und dem K+/H+-Symporter DmHAK5, die die hoch- und nieder-affine Kaliumaufnahme in den Dr{\"u}senzellen w{\"a}hrend der Beuteverdauung in Dionaea muscipula Fallen erm{\"o}glichen. Beide Transportmodule werden Kalzium-abh{\"a}ngig durch die Kinase CIPK23 und den Ca2+-Sensor CBL9 auf posttranslationaler Ebene reguliert. Zusammenfassend gelang es in dieser Arbeit Einblicke in die Kationenaufnahme w{\"a}hrend der N{\"a}hrstoffresorptionsphase der Venusfliegenfalle, Dionaea muscipula, zu gewinnen. Dabei wurde klar, dass Dionaea muscipula im Laufe ihrer Evolution zu einer karnivoren Pflanze, nicht neue Transportmodule zur N{\"a}hrstoffresorption aus der Beute entwickelte, sondern bekannte aus Wurzeln stammende Transportmodule umfunktionierte. Auf molekularer Ebene konnten die biophysikalischen Charakteristika der K+- und Na+-Transportproteine, sowie ihre Regulation entschl{\"u}sselt werden. Diese Erkenntnisse wurden schließlich in den Kontext des Beutefangs der Venusfliegenfalle gebracht und diskutiert.},
  subject      = {Venusfliegenfalle},
  language  = {de}
}
@article{BoehmScherzerKroletal.2016,
  author    = {B{\"o}hm, Jennifer and Scherzer, S{\"o}nke and Krol, Elzbieta and Kreuzer, Ines and von Meyer, Katharina and Lorey, Christian and Mueller, Thomas D. and Shabala, Lana and Monte, Isabel and Salano, Roberto and Al-Rasheid, Khaled A. S. and Rennenberg, Heinz and Shabala, Sergey and Neher, Erwin and Hedrich, Rainer},
  title     = {The Venus Flytrap Dionaea muscipula Counts Prey-Induced Action Potentials to Induce Sodium Uptake},
  series = {Current Biology},
  volume    = {26},
  journal   = {Current Biology},
  number    = {3},
  doi       = {10.1016/j.cub.2015.11.057},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128054},
  pages     = {286-295},
  year      = {2016},
  abstract  = {Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na+-rich animal and nutrition for the plant.},
  subject      = {Venusfliegenfalle},
  language  = {en}
}
@article{BoehmScherzerKroletal.2016,
  author    = {B{\"o}hm, Jennifer and Scherzer, S{\"o}nke and Krol, Elzbieta and Kreuzer, Ines and von Meyer, Katharina and Lorey, Christian and Mueller, Thomas D. and Shabala, Lana and Monte, Isabel and Solano, Roberto and Al-Rasheid, Khaled A. S. and Rennenberg, Heinz and Shabala, Sergey and Neher, Erwin and Hedrich, Rainer},
  title     = {The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake},
  series = {Current Biology},
  volume    = {26},
  journal   = {Current Biology},
  number    = {3},
  doi       = {10.1016/j.cub.2015.11.057},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190870},
  pages     = {286-295},
  year      = {2016},
  abstract  = {Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na\(^+\)-rich animal and nutrition for the plant.},
  language  = {en}
}
@phdthesis{Buechsenschuetz2005,
  author    = {B{\"u}chsensch{\"u}tz, Kai},
  title     = {Struktur und r{\"a}umlich-zeitliches Expressionsverhalten von Kaliumkan{\"a}len bei Zea mays},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-17522},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2005},
  abstract  = {Bei Zea mays wurden neue Kaliumkan{\"a}le der Shaker-Familie isoliert, charakterisiert und zusammen mit bereits bekannten Vertretern dieser Familie hinsichtlich m{\"o}glicher Aufgaben und Interaktionen untersucht.},
  subject      = {Mais},
  language  = {de}
}
@article{BuedelVivasLange2013,
  author    = {B{\"u}del, Burkhard and Vivas, Mercedes and Lange, Otto L.},
  title     = {Lichen species dominance and the resulting photosynthetic behavior of sonoran desert soil crust types (Baja California, Mexico)},
  series = {Ecological Processes},
  volume    = {2},
  journal   = {Ecological Processes},
  number    = {6},
  doi       = {http://dx.doi.org/10.1186/2192-1709-2-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131878},
  year      = {2013},
  abstract  = {Introduction: Lichen dominated biological soil crusts (BSCs) occur over large areas in the Sonoran Desert of the southwestern USA and northwest Mexico. In Baja California BSCs show a distinct patchiness and several types can be distinguished. Two chlorolichen- and two cyanolichen-dominated BSCs were selected. We hypothesize that patchiness and the resulting domination of certain functional lichen groups will result in patchiness of photosynthetic CO2-uptake related to environmental factors as well. Methods: Four different soil crust samples were placed in cuvettes and their CO2 exchange was recorded in an open system with an infrared gas analyzer. Air blown over the BSCs had a controlled CO2 content of 350 ppm. Four cuvettes were operated in parallel. Photosynthetic CO2 exchange was continually recorded throughout the experiment. Results: Besides the dominating chlorolichens Psora decipiens and Placidium squamulosum and the cyanolichens Peltula patellata and P. richardsii, several other lichen species and 12 cyanobacterial species were found in the biological soil crusts sampled. The chlorolichen BSCs already gained positive net photosynthesis with high air humidity alone, while the cyanolichen types did not, but showed smaller CO2-uptake depression after water suprasaturation. Such specific net photosynthesis responses to mode of hydration and to crust water content seem to correlate with precipitation characteristics of their habitat. Conclusions: Species specific photosynthetic performance related to activation of respiration and net photosynthesis as well as to crust water content help to explain niche occupation and species composition of BSCs. Different functional types have to be considered when they have a patchy distribution.},
  language  = {en}
}
@article{CardaniSardiLaFerlaetal.2014,
  author    = {Cardani, Diego and Sardi, Claudia and La Ferla, Barbara and D'Orazio, Guiseppe and Sommariva, Michele and Marcucci, Fabrizio and Olivero, Daniela and Tagliabue, Elda and Koepsell, Hermann and Nicotra, Francesco and Balsari, Andrea and Rumio, Christiano},
  title     = {Sodium glucose cotransporter 1 ligand BLF501 as a novel tool for management of gastrointestinal mucositis},
  series = {Molecular Cancer},
  volume    = {13},
  journal   = {Molecular Cancer},
  number    = {23},
  issn      = {1476-4598},
  doi       = {10.1186/1476-4598-13-23},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117352},
  year      = {2014},
  abstract  = {Background: Recent studies demonstrated that engagement of sodium glucose transporter 1 (SGLT-1) by orally administered D-glucose protects the intestinal mucosa from lipopolysaccharide (LPS)-induced injury. We tested whether SGLT-1 engagement might protect the intestinal mucosa from doxorubicin (DXR)- and 5-fluorouracil (5-FU)-induced injury in animal models mimicking acute or chronic mucositis. Methods: Mice were treated intraperitoneally with DXR, alone or in combination with 5-FU, and orally with BLF501, a glucose-derived synthetic compound with high affinity for SGLT-1. Intestinal mucosal epithelium integrity was assessed by histological analysis, cellular proliferation assays, real-time PCR gene expression assays and Western blot assays. Student's t-test (paired two-tailed) and X-2 analyses were used for comparisons between groups. Differences were considered significant at p < 0.05. Results: BLF501 administration in mice treated with DXR and/or 5-FU decreased the injuries to the mucosa in terms of epithelial integrity and cellular proliferative ability. Co-treatment with BLF501 led to a normal expression and distribution of both zonula occludens-1 (ZO-1) and beta-catenin, which were underexpressed after treatment with either chemotherapeutic agent alone. BLF501 administration also restored normal expression of caspase-3 and ezrin/radixin/moesin (ERM), which were overexpressed after treatment with DXR and 5-FU. In SGLT1-/- mice, BLF501 had no detectable effects. BLF501 administration in wild-type mice with growing A431 tumors did not modify antitumor activity of DXR. Conclusions: BLF501-induced protection of the intestinal mucosa is a promising novel therapeutic approach to reducing the severity of chemotherapy-induced mucositis.},
  language  = {en}
}
@phdthesis{CarmonaArana2015,
  author    = {Carmona Arana, Jos{\´e} Antonio},
  title     = {Regulation Tumornekrosefaktor (TNF) Rezeptor assoziierter Signalwege durch das Adapterprotein TRAF1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128735},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {TWEAK ist ein zu der TNF-Superfamilie (Tumor Necrosis Factor) zugeh{\"o}riges Zytokin, welches in Form l{\"o}slicher und membranst{\"a}ndiger Molek{\"u}le vorkommt. Beide Formen des Liganden k{\"o}nnen an den Rezeptor (Fn14) binden. Viele verschiedene intrazellul{\"a}re Signalwege werden durch den Fn14 aktiviert, beispielweise Erk1/2, JNK, Jun und STAT3, vor allem jedoch das NFkB. L{\"o}sliches und membranst{\"a}ndiges TWEAK zeigen eine {\"a}hnliche Aktivierungseffizienz bez{\"u}glich des alternativen NFkB-Signalwegs, wohingegen membranst{\"a}ndiges TWEAK weit besser als l{\"o}sliches TWEAK den klassischen NFkB-Signalweg aktiviert. In der vorliegenden Arbeit wurde zun{\"a}chst die TWEAK-vermittelte Induzierbarkeit von verschiedenen Zielgenen des NFkB-Systems untersucht. L{\"o}sliches TWEAK zeigte einen weit schw{\"a}cheren aktivierenden Effekt auf den klassischen NFkB-Signalweg als TNF, das ein sehr guter Aktivator des klassischen NFkB-Systems ist (Abb. 5, 6). Nichtsdestotrotz war TWEAK imstande eine st{\"a}rkere TRAF1-Induktion als TNF herbeizuf{\"u}hren (Abbildung 7, 8). TRAF1 ist ein durch NFkB-System stark reguliertes Gen. Um posttranskriptionelle TRAF1-Modifikationen als Ursache f{\"u}r die unerwartet gute TRAF1-Induktion durch l{\"o}sliches TWEAK auszuschließen, wurde die TRAF1-Expression nach Proteasom- und Caspasen-Inhibition untersucht (Abbildung 9). Dies ergab keinen Hinweis auf einen Einfluss dieser Prozessen auf der TRAF1-Expression. Mittels des IKK2-spezifischen Inhibitor TPCA-1 wurde die TWEAK-vermittelte TRAF1-Induktion Zelltyp-abh{\"a}ngig gehemmt, wohingegen die TNF-vermittelte Induktion von TRAF1 in allen Zelllinien vollst{\"a}ndig inhibiert wurde (Abbildung 13). Versuche mit dem NEDD8-aktivierenden Enzym (NAE) Inhibitor MLN4924, resultierten in einer totalen Inhibition der TRAF1-Expression in allen TWEAK- und TNF-stimulierten Zellen (Abbildung 14). Diese Befunde sprechen daf{\"u}r, dass bei der TWEAK-vermittelten TRAF1-Expression beide Zweige des NFkB-Signalwegs Zelltyp-abh{\"a}ngig beteiligt sind. Die Oligomerisierung der Liganden der TNF-Familie verst{\"a}rkt oft ihre Aktivit{\"a}t. Oligomerisiertes TWEAK imitiert die biologische Aktivit{\"a}t von membranst{\"a}ndigem TWEAK. L{\"o}sliches TWEAK wurde mit einem anti-Flag Antik{\"o}rper oligomerisiert und die TRAF1-Induktion durch den alternativen NFkB-Signalweg wurde analysiert Oligomerisiertes TWEAK aktivierte Zelltyp-unabh{\"a}ngig den klassischen NFkB-Signalweg st{\"a}rker als l{\"o}sliches TWEAK, wohingegen kein Effekt auf die TRAF1-Induktion oder auf die Aktivierung den alternativen NFkB-Signalweg festgestellt wurde (Abbildung 11, 12). TWEAK ist imstande die TRAF2-vermittelte CD40-Induktion des klassischen NFkB-Signalwegs zu hemmen (Abbildung 16, 17). Um den Beitrag von TWEAK-Induziertem TRAF1 zur CD40-Inhibition zu herauszufinden, wurden TRAF1-stabil transfizierte 786O- und U2OS-Zellen hergestellt (Abbildung 19). Die CD40-Induzierte IkBa-Degradation und IL8/6 Produktion war in den TRAF1-Transfektanten als auch in mit l{\"o}slichem TWEAK vorbehandelte Zellen stark inhibiert (Abbildung 21, 22), wobei die CD40-Expression und CD40/CD40L-Interaktion unver{\"a}ndert blieb (Abbildung 20). Diese Ergebnisse sprechen f{\"u}r einen wichtigen Beitrag des Adaptorprotein TRAF1 in der TWEAK-vermittelte Inhibition der CD40-induzierte Aktivierung des klassischen NFkB-Signalwegs.},
  subject      = {Antigen CD40},
  language  = {de}
}
@article{CarpanetoKoepsellBambergetal.2010,
  author    = {Carpaneto, Armando and Koepsell, Hermann and Bamberg, Ernst and Hedrich, Rainer and Geiger, Dietmar},
  title     = {Sucrose- and H+-Dependent Charge Movements Associated with the Gating of Sucrose Transporter ZmSUT1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68538},
  year      = {2010},
  abstract  = {Background: In contrast to man the majority of higher plants use sucrose as mobile carbohydrate. Accordingly protondriven sucrose transporters are crucial for cell-to-cell and long-distance distribution within the plant body. Generally very negative plant membrane potentials and the ability to accumulate sucrose quantities of more than 1 M document that plants must have evolved transporters with unique structural and functional features. Methodology/Principal Findings: To unravel the functional properties of one specific high capacity plasma membrane sucrose transporter in detail, we expressed the sucrose/H+ co-transporter from maize ZmSUT1 in Xenopus oocytes. Application of sucrose in an acidic pH environment elicited inward proton currents. Interestingly the sucrose-dependent H+ transport was associated with a decrease in membrane capacitance (Cm). In addition to sucrose Cm was modulated by the membrane potential and external protons. In order to explore the molecular mechanism underlying these Cm changes, presteady-state currents (Ipre) of ZmSUT1 transport were analyzed. Decay of Ipre could be best fitted by double exponentials. When plotted against the voltage the charge Q, associated to Ipre, was dependent on sucrose and protons. The mathematical derivative of the charge Q versus voltage was well in line with the observed Cm changes. Based on these parameters a turnover rate of 500 molecules sucrose/s was calculated. In contrast to gating currents of voltage dependentpotassium channels the analysis of ZmSUT1-derived presteady-state currents in the absence of sucrose (I =Q/t) was sufficient to predict ZmSUT1 transport-associated currents. Conclusions: Taken together our results indicate that in the absence of sucrose, 'trapped' protons move back and forth between an outer and an inner site within the transmembrane domains of ZmSUT1. This movement of protons in the electric field of the membrane gives rise to the presteady-state currents and in turn to Cm changes. Upon application of external sucrose, protons can pass the membrane turning presteady-state into transport currents.},
  language  = {en}
}
@article{ChengMacIntyreRamadanAbdelmohsenetal.2015,
  author    = {Cheng, Cheng and MacIntyre, Lynsey and Ramadan Abdelmohsen, Usama and Horn, Hannes and Polymenakou, Paraskevi N. and Edrada-Ebel, RuAngelie and Hentschel, Ute},
  title     = {Biodiversity, Anti-Trypanosomal Activity Screening, and Metabolomic Profiling of Actinomycetes Isolated from Mediterranean Sponges},
  series = {PLoS One},
  volume    = {10},
  journal   = {PLoS One},
  number    = {9},
  doi       = {10.1371/journal.pone.0138528},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125138},
  pages     = {e0138528},
  year      = {2015},
  abstract  = {Marine sponge-associated actinomycetes are considered as promising sources for the discovery of novel biologically active compounds. In the present study, a total of 64 actinomycetes were isolated from 12 different marine sponge species that had been collected offshore the islands of Milos and Crete, Greece, eastern Mediterranean. The isolates were affiliated to 23 genera representing 8 different suborders based on nearly full length 16S rRNA gene sequencing. Four putatively novel species belonging to genera Geodermatophilus, Microlunatus, Rhodococcus and Actinomycetospora were identified based on a 16S rRNA gene sequence similarity of < 98.5\% to currently described strains. Eight actinomycete isolates showed bioactivities against Trypanosma brucei brucei TC221 with half maximal inhibitory concentration (IC50) values <20 μg/mL. Thirty four isolates from the Milos collection and 12 isolates from the Crete collection were subjected to metabolomic analysis using high resolution LC-MS and NMR for dereplication purposes. Two isolates belonging to the genera Streptomyces (SBT348) and Micromonospora (SBT687) were prioritized based on their distinct chemistry profiles as well as their anti-trypanosomal activities. These findings demonstrated the feasibility and efficacy of utilizing metabolomics tools to prioritize chemically unique strains from microorganism collections and further highlight sponges as rich source for novel and bioactive actinomycetes.},
  language  = {en}
}
@article{ChengOthmanStopperetal.2017,
  author    = {Cheng, Cheng and Othman, Eman M. and Stopper, Helga and Edrada-Ebel, RuAngelie and Hentschel, Ute and Abdelmohsen, Usama Ramadan},
  title     = {Isolation of petrocidin A, a new cytotoxic cyclic dipeptide from the marine sponge-derived bacterium \(Streptomyces\) sp. SBT348},
  series = {Marine Drugs},
  volume    = {15},
  journal   = {Marine Drugs},
  number    = {12},
  doi       = {10.3390/md15120383},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172644},
  year      = {2017},
  abstract  = {A new cyclic dipeptide, petrocidin A (\(\textbf{1}\)), along with three known compounds—2,3-dihydroxybenzoic acid (\(\textbf{2}\)), 2,3-dihydroxybenzamide (\(\textbf{3}\)), and maltol (\(\textbf{4}\))—were isolated from the solid culture of \(Streptomyces\) sp. SBT348. The strain \(Streptomyces\) sp. SBT348 had been prioritized in a strain collection of 64 sponge-associated actinomycetes based on its distinct metabolomic profile using liquid chromatography/high-resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance (NMR). The absolute configuration of all α-amino acids was determined by HPLC analysis after derivatization with Marfey's reagent and comparison with commercially available reference amino acids. Structure elucidation was pursued in the presented study by mass spectrometry and NMR spectral data. Petrocidin A (\(\textbf{1}\)) and 2,3-dihydroxybenzamide (\(\textbf{3}\)) exhibited significant cytotoxicity towards the human promyelocytic HL-60 and the human colon adenocarcinoma HT-29 cell lines. These results demonstrated the potential of sponge-associated actinomycetes for the discovery of novel and pharmacologically active natural products.},
  language  = {en}
}
@phdthesis{Chintalapati2013,
  author    = {Chintalapati, Chakravarthi},
  title     = {Ornithine decarboxylase is the receptor of regulatory protein RS1 (RSC1A1) mediating RS1 dependent shortterm regulation of glucose transporter SGLT1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85622},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {RS1 is the intron less singel copy gene involved in regulation of plasme membrane transporters. Ornithine decarboxylase is identified as the receptor of RS1 specific for the release of vesicles containing SGLT1 specifically at the trans-golgi network. RS1 decreases the activity of ODC there by inhibiting the release of vesicles containing specifically SGLT1.},
  subject      = {Ornithindecarboxylase},
  language  = {en}
}
@article{ChopraBiehlSteinfattetal.2016,
  author    = {Chopra, Martin and Biehl, Marlene and Steinfatt, Tim and Brandl, Andreas and Kums, Juliane and Amich, Jorge and Vaeth, Martin and Kuen, Janina and Holtappels, Rafaela and Podlech, J{\"u}rgen and Mottok, Anja and Kraus, Sabrina and Jord{\´a}n-Garotte, Ana-Laura and B{\"a}uerlein, Carina A. and Brede, Christian and Ribechini, Eliana and Fick, Andrea and Seher, Axel and Polz, Johannes and Ottmueller, Katja J. and Baker, Jeannette and Nishikii, Hidekazu and Ritz, Miriam and Mattenheimer, Katharina and Schwinn, Stefanie and Winter, Thorsten and Sch{\"a}fer, Viktoria and Krappmann, Sven and Einsele, Hermann and M{\"u}ller, Thomas D. and Reddehase, Matthias J. and Lutz, Manfred B. and M{\"a}nnel, Daniela N. and Berberich-Siebelt, Friederike and Wajant, Harald and Beilhack, Andreas},
  title     = {Exogenous TNFR2 activation protects from acute GvHD via host T reg cell expansion},
  series = {Journal of Experimental Medicine},
  volume    = {213},
  journal   = {Journal of Experimental Medicine},
  number    = {9},
  doi       = {10.1084/jem.20151563},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187640},
  pages     = {1881-1900},
  year      = {2016},
  abstract  = {Donor CD4\(^+\)Foxp3\(^+\) regulatory T cells (T reg cells) suppress graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (HCT allo-HCT]). Current clinical study protocols rely on the ex vivo expansion of donor T reg cells and their infusion in high numbers. In this study, we present a novel strategy for inhibiting GvHD that is based on the in vivo expansion of recipient T reg cells before allo-HCT, exploiting the crucial role of tumor necrosis factor receptor 2 (TNFR2) in T reg cell biology. Expanding radiation-resistant host T reg cells in recipient mice using a mouse TNFR2-selective agonist before allo-HCT significantly prolonged survival and reduced GvHD severity in a TNFR2-and T reg cell-dependent manner. The beneficial effects of transplanted T cells against leukemia cells and infectious pathogens remained unaffected. A corresponding human TNFR2-specific agonist expanded human T reg cells in vitro. These observations indicate the potential of our strategy to protect allo-HCT patients from acute GvHD by expanding T reg cells via selective TNFR2 activation in vivo.},
  language  = {en}
}
@article{CicovaDejungSkalickyetal.2016,
  author    = {Cicova, Zdenka and Dejung, Mario and Skalicky, Tomas and Eisenhuth, Nicole and Hanselmann, Steffen and Morriswood, Brooke and Figueiredo, Luisa M. and Butter, Falk and Janzen, Christian J.},
  title     = {Two flagellar BAR domain proteins in Trypanosoma brucei with stage-specific regulation},
  series = {Scientific Reports},
  volume    = {6},
  journal   = {Scientific Reports},
  doi       = {10.1038/srep35826},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181021},
  year      = {2016},
  abstract  = {Trypanosomes are masters of adaptation to different host environments during their complex life cycle. Large-scale proteomic approaches provide information on changes at the cellular level, and in a systematic way. However, detailed work on single components is necessary to understand the adaptation mechanisms on a molecular level. Here, we have performed a detailed characterization of a bloodstream form (BSF) stage-specific putative flagellar host adaptation factor Tb927.11.2400, identified previously in a SILAC-based comparative proteome study. Tb927.11.2400 shares 38\% amino acid identity with TbFlabarin (Tb927.11.2410), a procyclic form (PCF) stage-specific flagellar BAR domain protein. We named Tb927.11.2400 TbFlabarin-like (TbFlabarinL), and demonstrate that it originates from a gene duplication event, which occurred in the African trypanosomes. TbFlabarinL is not essential for the growth of the parasites under cell culture conditions and it is dispensable for developmental differentiation from BSF to the PCF in vitro. We generated TbFlabarinL-specific antibodies, and showed that it localizes in the flagellum. Co-immunoprecipitation experiments together with a biochemical cell fractionation suggest a dual association of TbFlabarinL with the flagellar membrane and the components of the paraflagellar rod.},
  language  = {en}
}
@phdthesis{Dally2013,
  author    = {Dally, Iris},
  title     = {Entwicklung eines bioartifiziellen Rekonstruktionsgewebes f{\"u}r die Luftr{\"o}hrenchirugie und Umsetzung in einen GMP-Prozess},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-98422},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Das Ziel dieser Arbeit war die Entwicklung eines vaskularisierten, autologen Implantats zur Behandlung von schweren Verletzungen der Trachea im Umfeld der guten Herstellungspraxis. Die Matrix besteht aus einem circa 14 cm langen St{\"u}ck porcinen, azellularisierten D{\"u}nndarm und BioVaSc (Biological Vascularized Scaffold) genannt wird. Dieses wird dann mit isolierten und kultivierten Zellen des Patienten besiedelt und reift f{\"u}r zwei Wochen in einem speziell hierf{\"u}r entwickelten Bioreaktorsystem. Danach erfolgt die Analyse bzw. die Implantation in den Patienten. Nach der Pr{\"a}paration und {\"U}berpr{\"u}fung der Qualit{\"a}t, erfolgte die Azellularisierung der BioVaSc zur Entfernung der porcinen Zellen und der enzymatische Abbau der DNS, unter Erhalt des nat{\"u}rlichen Gef{\"a}ßsystems. Hierf{\"u}r ist Natriumdesoxycholat verwendet worden, wobei R{\"u}ckst{\"a}nde davon das Ansiedeln der autologen Zellen negativ beeinflussen k{\"o}nnten. Deshalb wurde ein Test etabliert, mit dessen Hilfe, das Auswaschen der Azellularisierungsdetergenz bis zur Sterilisation nachweisbar war. Des Weiteren k{\"o}nnten in der BioVaSc nat{\"u}rlicherweise enthaltene Endotoxine Immunreaktionen im sp{\"a}teren Empf{\"a}nger ausl{\"o}sen. Die gesetzlichen Grenzwerte konnten durch Modifikationen des Protokolls, unter Ber{\"u}cksichtigung der guten Herstellungspraxis, erreicht werden. Weiterhin konnte histologisch eine weitgehende DNS- und Zellfreiheit nachgewiesen werden, in der quantitativen Analyse ergab sich eine Abreicherung von 97\% im Vergleich zum Ausgangsmaterial. Zur Bestimmung der funktionellen Stabilit{\"a}t der azellularisierten Matrix wurde die maximal tolerable Zugspannung bestimmt. Zur Besiedlung der Gef{\"a}ße der Matrix wurden mikrovaskul{\"a}re Endothelzellen und f{\"u}r das Lumen Fibroblasten und Skelettmuskelzellen verwendet. Die Protokolle zur Isolation und Kultur sind hierzu unter den Bedingungen der guten Herstellungspraxis etabliert, optimiert und mit, soweit m{\"o}glich, zertifizierten Reagenzien durchgef{\"u}hrt worden. Zur genauen Charakterisierung der Zellen wurden diese immunhistologisch {\"u}ber vier Passagen analysiert, wobei sich je nach Zelltyp und Differenzierungsstadium unterschiedliche Expressionsmuster ergaben. Zur Herstellung des autologen Implantats wurden zun{\"a}chst die mikrovaskul{\"a}ren Endothelzellen in das vorhandene Gef{\"a}ßsystem der BioVaSc eingebracht und dann f{\"u}r sieben Tage im etablierten Bioreaktorsystem kultiviert. Danach erfolgte die Besiedlung des Lumens mit Skelettmuskelzellen und Fibroblasten und die weitere siebent{\"a}gige Kultur im Bioreaktorsystem. Die Besiedlung des Gef{\"a}ßsystems musste optimiert werden, um sowohl die Besiedlungsdichte zu steigern als auch die Effizienz zu erh{\"o}hen. Das Lumen konnte mit der etablierten Methode vollst{\"a}ndig besiedelt werden. Nach vierzehnt{\"a}giger Kultur im Bioreaktorsystem erfolgte die Kontrolle der Zellvitalit{\"a}t, wobei sowohl in den Gef{\"a}ßstrukturen als auch im Lumen der BioVaSc vitale Zellen nachweisbar waren. Histologische Analysen zeigten, dass die mikrovaskul{\"a}ren Endothelzellen in den verbliebenen vaskul{\"a}ren Strukturen CD31 und den vWF exprimieren. Wohingegen die histologische Unterscheidung zwischen Fibroblasten und Skelettmuskelzellen nicht m{\"o}glich ist. Zus{\"a}tzlich wurde die BioVaSc mit upcyte mvEC der Firma Medicyte besiedelt. Nach der vierzehnt{\"a}gigen Kultur im Bioreaktorsystem waren die Zellen sowohl in den Gef{\"a}ßstrukturen als auch im Lumen und im Bindegewebe vital nachweisbar. In der histologischen Analyse konnte die Ausbildung von CD31, eNOS und vWF nachgewiesen werden. Des Weiteren wurde die Matrix mit mesenchymalen Stammzellen besiedelt, um zu analysieren, ob die Scherkr{\"a}fte die Ausbildung endothelialer Marker stimulieren k{\"o}nnen. Nach vierzehnt{\"a}giger Kultur konnte in den histologischen Analysen keine Ausbildung von CD31 oder dem vWF gefunden, allerdings vitale Zellen nachgewiesen werden.},
  subject      = {Regenerative Medizin},
  language  = {de}
}
@article{DashtiGrkovicAbdelmohsenetal.2014,
  author    = {Dashti, Yousef and Grkovic, Tanja and Abdelmohsen, Usama Ramadan and Hentschel, Ute and Quinn, Ronald J.},
  title     = {Production of Induced Secondary Metabolites by a Co-Culture of Sponge-Associated Actinomycetes, Actinokineospora sp EG49 and Nocardiopsis sp RV163},
  series = {MARINE DRUGS},
  volume    = {12},
  journal   = {MARINE DRUGS},
  number    = {5},
  issn      = {1660-3397},
  doi       = {10.3390/md12053046},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116547},
  pages     = {3046-3059},
  year      = {2014},
  abstract  = {Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by H-1 NMR. Ten known compounds, including angucycline, diketopiperazine and beta-carboline derivatives 1-10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a, 6,11a, 12-tetrahydro-5a, 11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes.},
  language  = {en}
}