@phdthesis{PompergebMueller2019, author = {Pomper [geb. M{\"u}ller], Laura Dorothea}, title = {Unterschiede in Frontaler Kortex Oxygenierung in zweierlei Risikogruppen der Alzheimer Demenz}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Die verbesserte medizinische Versorgung f{\"u}hrt zu einer zunehmenden Lebenserwartung unserer Gesellschaft. Damit steigt auch die sozio{\"o}konomische Relevanz neurodegenerativer Erkrankungen kontinuierlich. F{\"u}r die Alzheimer Demenz (AD), die dabei die h{\"a}ufigste Ursache darstellt, stehen bisher keine krankheitsmodifizierenden Behandlungsoptionen zur Verf{\"u}gung. Die lange pr{\"a}klinische Phase der Erkrankung birgt jedoch großes Potential f{\"u}r die Entwicklung neuer Behandlungsoptionen. Das Untersuchen von Risikogruppen ist f{\"u}r die Identifikation von Pr{\"a}diktoren einer sp{\"a}teren AD Manifestation von besonderem Interesse. In diesem Zusammenhang werden insbesondere das Vorliegen genetischer Risikokonstellationen, wie dem Apolipoprotein E (APOE) Ɛ4-Allel, sowie kognitiver Risikofaktoren, wie der „leichten kognitiven Beeintr{\"a}chtigung" (MCI), diskutiert. Die Identifikation pr{\"a}klinischer Aktivierungsunterschiede in relevanten Gehirnregionen von Risikogruppen kann als Basis f{\"u}r die Entwicklung neurofunktioneller Fr{\"u}herkennungs-Marker dienen. Der pr{\"a}frontale Kortex (PFC), welcher mit der Steuerung von Exekutivfunktionen assoziiert wird, hat sich in diesem Zusammenhang in bisherigen Studien als eine relevante Schl{\"u}sselregion manifestiert. Aufgrund der aufwendigen und kostenintensiven bildgebenden Untersuchungsmethoden, sind die genauen Prozesse jedoch noch unklar. Ziel der vorliegenden Arbeit war es daher, Unterschiede in der PFC Oxygenierung in zweierlei Risikogruppen der AD mit einer kosteng{\"u}nstigeren Bildgebungsmethode, der funktionellen Nahinfrarot Spektroskopie (fNIRS), zu untersuchen. Daf{\"u}r wurde in einem ersten Schritt, der Trailmaking Test (TMT), ein weitverbreiteter neuropsychologischer Test zur Erfassung exekutiver Funktionen, f{\"u}r fNIRS implementiert. Als Grundlage f{\"u}r die Untersuchung fr{\"u}hpathologischer Prozesse, wurden zun{\"a}chst gesunde Alterungsprozesse betrachtet. Der Vergleich von jungen und {\"a}lteren Probanden (n = 20 pro Gruppe) wies neben der Eignung der Testimplementierung f{\"u}r fNIRS auf eine spezifische bilaterale PFC Oxygenierung hin, welche bei jungen Probanden rechtshemisph{\"a}risch lateralisiert war. {\"A}ltere Probanden hingegen zeigten bei vergleichbaren Verhaltensdaten insgesamt mehr signifikante Kan{\"a}le sowie eine Abnahme der Lateralisierung. Dies kann als zus{\"a}tzlicher Bedarf an Ressourcen in gesunden Alterungsprozessen interpretiert werden. Im Rahmen der Hauptstudie wurden anschließend insgesamt 604 {\"a}ltere Probanden im Alter von 70 bis 76 Jahren untersucht. Zun{\"a}chst wurde die genetische Risikogruppe der Ɛ4-Allel-Tr{\"a}ger (n = 78) mit den neutralen Ɛ3-Allel-Tr{\"a}gern (n = 216) und den Tr{\"a}gern des als protektiv geltenden Ɛ2-Allels (n = 50) verglichen. Hierbei zeigte sich eine geringere Oxygenierung der Risikogruppe bei geringer Aufgabenschwierigkeit, w{\"a}hrend sich ein erh{\"o}hter Oxygenierungsanstieg im medialen PFC mit steigender Aufgabenschwierigkeit zeigte. Dies deutet auf einen erh{\"o}hten Bedarf an neuronalen Kontrollmechanismen der Risikogruppe zur Bew{\"a}ltigung der steigenden Aufgabenschwierigkeit hin. Die protektive Gruppe zeigte hingegen eine erh{\"o}hte Oxygenierung im ventralen PFC mit steigender Aufgabenschwierigkeit, was m{\"o}glicherweise auf einen pr{\"a}ventiven Effekt hindeuten k{\"o}nnte. Weiterf{\"u}hrend wurden MCI-Patienten mit gesunden Probanden (n = 57 pro Gruppe) hinsichtlich des kognitiven Risikofaktors verglichen. Hierbei zeigte sich ein punktuell reduzierter Oxygenierunganstieg der MCI Patienten mit steigender Aufgabenschwierigkeit vor allem im ventralen PFC bei ebenfalls stabiler Verhaltensleistung. Die gefundene Reduktion k{\"o}nnte ein Zeichen f{\"u}r eine aufgebrauchte kognitive Reserve sein, welche Einbußen auf Verhaltensebene voranzugehen scheint. Diese charakteristischen Unterschiede in den frontalen Oxygenierungsmustern von Risikogruppen (APOE, MCI) k{\"o}nnten als Biomarker zur Fr{\"u}herkennung von AD noch vor dem Auftreten kognitiver Einbußen dienen. Die fNIRS-Untersuchung w{\"a}hrend der Durchf{\"u}hrung des TMT hat sich in diesem Zusammenhang als potentielles Instrument zur Fr{\"u}hdiagnose der pr{\"a}klinischen Phase der AD als geeignet erwiesen. Die Ergebnisse werden unter Einbezug des wissenschaftlichen Kontexts interpretiert und Implikationen f{\"u}r weitere notwendige Studien sowie die klinische Anwendbarkeit diskutiert.}, subject = {Alzheimerkrankheit}, language = {de} } @phdthesis{MuellerHuebner2020, author = {M{\"u}ller-H{\"u}bner, Laura}, title = {The role of nuclear architecture in the context of antigenic variation in Trypanosoma brucei}, doi = {10.25972/OPUS-18707}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187074}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Antigenic variation of surface proteins is a commonly used strategy among pathogens to evade the host immune response [63]. The mechanism underlying antigenic variation relies on monoallelic exclusion of a single gene from a hypervariable multigene family combined with repeated, systematic changes in antigen expression. In many systems, these gene families are arranged in subtelomeric contingency loci that are subject to both transcriptional repression and enhanced mutagenesis and recombination [16]. Eviction of a selected gene from a repressed antigen repertoire can be achieved e.g. by recombination into a dedicated, transcriptionally permissive site or by local epigenetic alterations in chromatin composition of the selected gene. Both processes are ultimately affected by genome architecture. Architectural proteins controlling antigenic variation have, however, remained elusive in any pathogen. The unicellular protozoan parasite Trypanosoma brucei evades the host immune response by periodically changing expression of a single variant surface glycoprotein (VSG) from a repertoire of ~3000 VSG genes - the largest mutually exclusively expressed gene family described today. To activate a selected VSG gene, it needs to be located in a dedicated expression site that becomes subject to relocation into a distinct, transcriptionally active subnuclear compartment, the expression site body (ESB). Whereas this emphasizes the importance of nuclear architecture in regulating antigen expression in T. brucei, the mechanisms underlying spatial positioning of DNA in T. brucei are not well understood. In this study I applied genome-wide chromosome conformation capture (Hi-C) to obtain a comprehensive picture of the T. brucei genome in three dimensions, both in procyclic and bloodstream form parasites. Hi-C revealed a highly structured nucleus with megabase chromosomes occupying distinct chromosome territories. Further, specific trans interactions between chromosomes, among which are clusters of centromeres, rRNA genes and procyclins became apparent. With respect to antigenic variation, Hi-C revealed a striking compaction of the subtelomeric VSG gene repertoire and a strong clustering of transcriptionally repressed VSG-containing expression sites. Further, Hi-C analyses confirmed the spatial separation of the actively transcribed from the silenced expression sites in three dimensions. I further sought to characterize architectural proteins mediating nuclear architecture in T. brucei. Whereas CTCF is absent in non-metazoans, we found cohesin to be expressed throughout the cell cycle, emphasizing a function beyond sister chromatid cohesion in S-phase. By Chromatin-Immunoprecipitation with sequencing (ChIPseq), I found cohesin enrichment to coincide with the presence of histone H3 vari- ant (H3.V) and H4 variant (H4.V). Most importantly, cohesin and the histone variants were enriched towards the VSG gene at silent and active expression sites. While the deletion of H3.V led to increased clustering of expression sites in three dimensions and increased chromatin accessibility at expression site promoters, the additional deletion of H4.V increased chromatin accessibility at expression sits even further. RNAseq showed that mutually exclusive VSG expression was lost in H3.V and H4.V single and double deletion mutants. Immunofluorescence imaging of surface VSGs, flow cytometry and single-cell RNAseq revealed a progressive loss of VSG-2 expression, indicative of an increase in VSG switching rate in the H3.V/H4.V double deletion mutants. Using long-read sequencing technology, we found that VSG switching occurred via recombination and concluded, that the concomitant increase in spatial proximity and accessibility among expression sites facilitated the recombination event. I therefore identified the histone variants H3.V and H4.V to act at the interface of global nuclear architecture and chromatin accessibility and to represent a link between genome architecture and antigenic variation.}, subject = {Trypanosoma brucei brucei}, 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{BorchersMuellerSynofziketal.2013, author = {Borchers, Svenja and M{\"u}ller, Laura and Synofzik, Matthis and Himmelbach, Marc}, title = {Guidelines and quality measures for the diagnosis of optic ataxia}, series = {Frontiers in Human Neuroscience}, volume = {7}, journal = {Frontiers in Human Neuroscience}, number = {324}, issn = {1662-5161}, doi = {10.3389/fnhum.2013.00324}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122439}, year = {2013}, abstract = {Since the first description of a systematic mis-reaching by Balint in 1909, a reasonable number of patients showing a similar phenomenology, later termed optic ataxia (OA), has been described. However, there is surprising inconsistency regarding the behavioral measures that are used to detect OA in experimental and clinical reports, if the respective measures are reported at all. A typical screening method that was presumably used by most researchers and clinicians, reaching for a target object in the peripheral visual space, has never been evaluated. We developed a set of instructions and evaluation criteria for the scoring of a semi-standardized version of this reaching task. We tested 36 healthy participants, a group of 52 acute and chronic stroke patients, and 24 patients suffering from cerebellar ataxia. We found a high interrater reliability and a moderate test-retest reliability comparable to other clinical instruments in the stroke sample. The calculation of cut-off thresholds based on healthy control and cerebellar patient data showed an unexpected high number of false positives in these samples due to individual outliers that made a considerable number of errors in peripheral reaching. This study provides first empirical data from large control and patient groups for a screening procedure that seems to be widely used but rarely explicitly reported and prepares the grounds for its use as a standard tool for the description of patients who are included in single case or group studies addressing optic ataxia similar to the use of neglect, extinction, or apraxia screening tools.}, language = {en} } @article{DavisYuKeenanetal.2013, author = {Davis, Lea K. and Yu, Dongmei and Keenan, Clare L. and Gamazon, Eric R. and Konkashbaev, Anuar I. and Derks, Eske M. and Neale, Benjamin M. and Yang, Jian and Lee, S. Hong and Evans, Patrick and Barr, Cathy L. and Bellodi, Laura and Benarroch, Fortu and Berrio, Gabriel Bedoya and Bienvenu, Oscar J. and Bloch, Michael H. and Blom, Rianne M. and Bruun, Ruth D. and Budman, Cathy L. and Camarena, Beatriz and Campbell, Desmond and Cappi, Carolina and Cardona Silgado, Julio C. and Cath, Danielle C. and Cavallini, Maria C. and Chavira, Denise A. and Chouinard, Sylvian and Conti, David V. and Cook, Edwin H. and Coric, Vladimir and Cullen, Bernadette A. and Deforce, Dieter and Delorme, Richard and Dion, Yves and Edlund, Christopher K. and Egberts, Karin and Falkai, Peter and Fernandez, Thomas V. and Gallagher, Patience J. and Garrido, Helena and Geller, Daniel and Girard, Simon L. and Grabe, Hans J. and Grados, Marco A. and Greenberg, Benjamin D. and Gross-Tsur, Varda and Haddad, Stephen and Heiman, Gary A. and Hemmings, Sian M. J. and Hounie, Ana G. and Illmann, Cornelia and Jankovic, Joseph and Jenike, Micheal A. and Kennedy, James L. and King, Robert A. and Kremeyer, Barbara and Kurlan, Roger and Lanzagorta, Nuria and Leboyer, Marion and Leckman, James F. and Lennertz, Leonhard and Liu, Chunyu and Lochner, Christine and Lowe, Thomas L. and Macciardi, Fabio and McCracken, James T. and McGrath, Lauren M. and Restrepo, Sandra C. Mesa and Moessner, Rainald and Morgan, Jubel and Muller, Heike and Murphy, Dennis L. and Naarden, Allan L. and Ochoa, William Cornejo and Ophoff, Roel A. and Osiecki, Lisa and Pakstis, Andrew J. and Pato, Michele T. and Pato, Carlos N. and Piacentini, John and Pittenger, Christopher and Pollak, Yehunda and Rauch, Scott L. and Renner, Tobias J. and Reus, Victor I. and Richter, Margaret A. and Riddle, Mark A. and Robertson, Mary M. and Romero, Roxana and Ros{\`a}rio, Maria C. and Rosenberg, David and Rouleau, Guy A. and Ruhrmann, Stephan and Ruiz-Linares, Andreas and Sampaio, Aline S. and Samuels, Jack and Sandor, Paul and Sheppard, Broke and Singer, Harvey S. and Smit, Jan H. and Stein, Dan J. and Strengman, E. and Tischfield, Jay A. and Valencia Duarte, Ana V. and Vallada, Homero and Van Nieuwerburgh, Flip and Veenstra-VanderWeele, Jeremy and Walitza, Susanne and Wang, Ying and Wendland, Jens R. and Westenberg, Herman G. M. and Shugart, Yin Yao and Miguel, Euripedes C. and McMahon, William and Wagner, Michael and Nicolini, Humberto and Posthuma, Danielle and Hanna, Gregory L. and Heutink, Peter and Denys, Damiaan and Arnold, Paul D. and Oostra, Ben A. and Nestadt, Gerald and Freimer, Nelson B. and Pauls, David L. and Wray, Naomi R. and Stewart, S. Evelyn and Mathews, Carol A. and Knowles, James A. and Cox, Nancy J. and Scharf, Jeremiah M.}, title = {Partitioning the Heritability of Tourette Syndrome and Obsessive Compulsive Disorder Reveals Differences in Genetic Architecture}, series = {PLoS Genetics}, volume = {9}, journal = {PLoS Genetics}, number = {10}, issn = {1553-7390}, doi = {10.1371/journal.pgen.1003864}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127377}, pages = {e1003864}, year = {2013}, abstract = {The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained by all SNPs for two phenotypically-related neurobehavioral disorders, obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), using GCTA. Our analysis yielded a heritability point estimate of 0.58 (se = 0.09, p = 5.64e-12) for TS, and 0.37 (se = 0.07, p = 1.5e-07) for OCD. In addition, we conducted multiple genomic partitioning analyses to identify genomic elements that concentrate this heritability. We examined genomic architectures of TS and OCD by chromosome, MAF bin, and functional annotations. In addition, we assessed heritability for early onset and adult onset OCD. Among other notable results, we found that SNPs with a minor allele frequency of less than 5\% accounted for 21\% of the TS heritability and 0\% of the OCD heritability. Additionally, we identified a significant contribution to TS and OCD heritability by variants significantly associated with gene expression in two regions of the brain (parietal cortex and cerebellum) for which we had available expression quantitative trait loci (eQTLs). Finally we analyzed the genetic correlation between TS and OCD, revealing a genetic correlation of 0.41 (se = 0.15, p = 0.002). These results are very close to previous heritability estimates for TS and OCD based on twin and family studies, suggesting that very little, if any, heritability is truly missing (i.e., unassayed) from TS and OCD GWAS studies of common variation. The results also indicate that there is some genetic overlap between these two phenotypically-related neuropsychiatric disorders, but suggest that the two disorders have distinct genetic architectures.}, language = {en} } @article{NguyenMuellerParketal.2014, author = {Nguyen, Tu N. and M{\"u}ller, Laura S. M. and Park, Sung Hee and Siegel, T. Nicolai and G{\"u}nzl, Arthur}, title = {Promoter occupancy of the basal class I transcription factor A differs strongly between active and silent VSG expression sites in Trypanosoma brucei}, series = {Nucleic Acid Research}, volume = {42}, journal = {Nucleic Acid Research}, number = {5}, issn = {1362-4962}, doi = {10.1093/nar/gkt1301}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117232}, pages = {3164-3176}, year = {2014}, abstract = {Monoallelic expression within a gene family is found in pathogens exhibiting antigenic variation and in mammalian olfactory neurons. Trypanosoma brucei, a lethal parasite living in the human bloodstream, expresses variant surface glycoprotein (VSG) from 1 of 15 bloodstream expression sites (BESs) by virtue of a multifunctional RNA polymerase I. The active BES is transcribed in an extranucleolar compartment termed the expression site body (ESB), whereas silent BESs, located elsewhere within the nucleus, are repressed epigenetically. The regulatory mechanisms, however, are poorly understood. Here we show that two essential subunits of the basal class I transcription factor A (CITFA) predominantly occupied the promoter of the active BES relative to that of a silent BES, a phenotype that was maintained after switching BESs in situ. In these experiments, high promoter occupancy of CITFA was coupled to high levels of both promoter-proximal RNA abundance and RNA polymerase I occupancy. Accordingly, fluorescently tagged CITFA-7 was concentrated in the nucleolus and the ESB. Because a ChIP-seq analysis found that along the entire BES, CITFA-7 is specifically enriched only at the promoter, our data strongly indicate that monoallelic BES transcription is activated by a mechanism that functions at the level of transcription initiation.}, language = {en} } @article{PeterBultinckMyantetal.2014, author = {Peter, Stefanie and Bultinck, Jennyfer and Myant, Kevin and Jaenicke, Laura A. and Walz, Susanne and M{\"u}ller, Judith and Gmachl, Michael and Treu, Matthias and Boehmelt, Guido and Ade, Casten P. and Schmitz, Werner and Wiegering, Armin and Otto, Christoph and Popov, Nikita and Sansom, Owen and Kraut, Norbert and Eilers, Martin}, title = {H Tumor cell-specific inhibition of MYC function using small molecule inhibitors of the HUWE1 ubiquitin ligase}, series = {EMBO Molecular Medicine}, volume = {6}, journal = {EMBO Molecular Medicine}, number = {12}, issn = {1757-4684}, doi = {10.15252/emmm.201403927}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118132}, pages = {1525-41}, year = {2014}, abstract = {Deregulated expression of MYC is a driver of colorectal carcinogenesis, necessitating novel strategies to inhibit MYC function. The ubiquitin ligase HUWE1 (HECTH9, ARF-BP1, MULE) associates with both MYC and the MYC-associated protein MIZ1. We show here that HUWE1 is required for growth of colorectal cancer cells in culture and in orthotopic xenograft models. Using high-throughput screening, we identify small molecule inhibitors of HUWE1, which inhibit MYC-dependent transactivation in colorectal cancer cells, but not in stem and normal colon epithelial cells. Inhibition of HUWE1 stabilizes MIZ1. MIZ1 globally accumulates on MYC target genes and contributes to repression of MYC-activated target genes upon HUWE1 inhibition. Our data show that transcriptional activation by MYC in colon cancer cells requires the continuous degradation of MIZ1 and identify a novel principle that allows for inhibition of MYC function in tumor cells.}, language = {en} } @article{GuhnDreslerAndreattaetal.2014, author = {Guhn, Anne and Dresler, Thomas and Andreatta, Marta and M{\"u}ller, Laura D. and Hahn, Tim and Tupak, Sara V. and Polak, Thomas and Deckert, J{\"u}rgen and Herrmann, Martin J.}, title = {Medial prefrontal cortex stimulation modulates the processing of conditioned fear}, doi = {10.3389/fnbeh.2014.00044}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111309}, year = {2014}, abstract = {The extinction of conditioned fear depends on an efficient interplay between the amygdala and the medial prefrontal cortex (mPFC). In rats, high-frequency electrical mPFC stimulation has been shown to improve extinction by means of a reduction of amygdala activity. However, so far it is unclear whether stimulation of homologues regions in humans might have similar beneficial effects. Healthy volunteers received one session of either active or sham repetitive transcranial magnetic stimulation (rTMS) covering the mPFC while undergoing a 2-day fear conditioning and extinction paradigm. Repetitive TMS was applied offline after fear acquisition in which one of two faces (CS+ but not CS-) was associated with an aversive scream (UCS). Immediate extinction learning (day 1) and extinction recall (day 2) were conducted without UCS delivery. Conditioned responses (CR) were assessed in a multimodal approach using fear-potentiated startle (FPS), skin conductance responses (SCR), functional near-infrared spectroscopy (fNIRS), and self-report scales. Consistent with the hypothesis of a modulated processing of conditioned fear after high-frequency rTMS, the active group showed a reduced CS+/CS- discrimination during extinction learning as evident in FPS as well as in SCR and arousal ratings. FPS responses to CS+ further showed a linear decrement throughout both extinction sessions. This study describes the first experimental approach of influencing conditioned fear by using rTMS and can thus be a basis for future studies investigating a complementation of mPFC stimulation to cognitive behavioral therapy (CBT).}, language = {en} } @article{BiehlEhlisMuelleretal.2013, author = {Biehl, Stefanie C. and Ehlis, Ann-Christine and M{\"u}ller, Laura D. and Niklaus, Andrea and Pauli, Paul and Herrmann, Martin J.}, title = {The impact of task relevance and degree of distraction on stimulus processing}, series = {BMC Neuroscience}, journal = {BMC Neuroscience}, doi = {10.1186/1471-2202-14-107}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97271}, year = {2013}, abstract = {Background The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated. Results Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses. Conclusions Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.}, language = {en} } @article{AmpattuHagmannLiangetal.2017, author = {Ampattu, Biju Joseph and Hagmann, Laura and Liang, Chunguang and Dittrich, Marcus and Schl{\"u}ter, Andreas and Blom, Jochen and Krol, Elizaveta and Goesmann, Alexander and Becker, Anke and Dandekar, Thomas and M{\"u}ller, Tobias and Schoen, Christoph}, title = {Transcriptomic buffering of cryptic genetic variation contributes to meningococcal virulence}, series = {BMC Genomics}, volume = {18}, journal = {BMC Genomics}, number = {282}, doi = {10.1186/s12864-017-3616-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157534}, year = {2017}, abstract = {Background: Commensal bacteria like Neisseria meningitidis sometimes cause serious disease. However, genomic comparison of hyperinvasive and apathogenic lineages did not reveal unambiguous hints towards indispensable virulence factors. Here, in a systems biological approach we compared gene expression of the invasive strain MC58 and the carriage strain α522 under different ex vivo conditions mimicking commensal and virulence compartments to assess the strain-specific impact of gene regulation on meningococcal virulence. Results: Despite indistinguishable ex vivo phenotypes, both strains differed in the expression of over 500 genes under infection mimicking conditions. These differences comprised in particular metabolic and information processing genes as well as genes known to be involved in host-damage such as the nitrite reductase and numerous LOS biosynthesis genes. A model based analysis of the transcriptomic differences in human blood suggested ensuing metabolic flux differences in energy, glutamine and cysteine metabolic pathways along with differences in the activation of the stringent response in both strains. In support of the computational findings, experimental analyses revealed differences in cysteine and glutamine auxotrophy in both strains as well as a strain and condition dependent essentiality of the (p)ppGpp synthetase gene relA and of a short non-coding AT-rich repeat element in its promoter region. Conclusions: Our data suggest that meningococcal virulence is linked to transcriptional buffering of cryptic genetic variation in metabolic genes including global stress responses. They further highlight the role of regulatory elements for bacterial virulence and the limitations of model strain approaches when studying such genetically diverse species as N. meningitidis.}, language = {en} } @article{HardulakMoriniereHausmannetal.2020, author = {Hardulak, Laura A. and Morini{\`e}re, J{\´e}r{\^o}me and Hausmann, Axel and Hendrich, Lars and Schmidt, Stefan and Doczkal, Dieter and M{\"u}ller, J{\"o}rg and Hebert, Paul D. N. and Haszprunar, Gerhard}, title = {DNA metabarcoding for biodiversity monitoring in a national park: Screening for invasive and pest species}, series = {Molecular Ecology Resources}, volume = {20}, journal = {Molecular Ecology Resources}, number = {6}, doi = {10.1111/1755-0998.13212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217812}, pages = {1542 -- 1557}, year = {2020}, abstract = {DNA metabarcoding was utilized for a large-scale, multiyear assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal component analysis of read count-based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of barcode index numbers (BINs) at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger-sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6\% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park.}, language = {en} } @article{KatzorkeZellerMuelleretal.2017, author = {Katzorke, Andrea and Zeller, Julia B. M. and M{\"u}ller, Laura D. and Lauer, Martin and Polak, Thomas and Reif, Andreas and Deckert, J{\"u}rgen and Herrmann, Martin J.}, title = {Reduced activity in the right inferior frontal gyrus in elderly APOE-E4 carriers during a verbal fluency task}, series = {Frontiers in Human Neuroscience}, volume = {11}, journal = {Frontiers in Human Neuroscience}, doi = {10.3389/fnhum.2017.00046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171892}, year = {2017}, abstract = {Apolipoprotein-E4 (APOE-E4) is a major genetic risk factor for developing Alzheimer's disease (AD). The verbal fluency task (VFT), especially the subtask category fluency, has shown to provide a good discrimination between cognitively normal controls and subjects with AD. Interestingly, APOE-E4 seems to have no effect on the behavioral performance during a VFT in healthy elderly. Thus, the purpose of the present study was to reveal possible compensation mechanisms by investigating the effect of APOE-E4 on the hemodynamic response in non-demented elderly during a VFT by using functional near-infrared spectroscopy (fNIRS). We compared performance and hemodynamic response of high risk APOE-E4/E4, -E3/E4 carriers with neutral APOE-E3/E3 non-demented subjects (N = 288; 70-77 years). No difference in performance was found. APOE-E4/E4, -E3/E4 carriers had a decreased hemodynamic response in the right inferior frontal junction (IFJ) with a corresponding higher response in the left middle frontal gyrus (MFG) during category fluency. Performance was correlated with the hemodynamic response in the MFG. We assume a compensation of decreased IFJ brain activation by utilizing the MFG during category fluency and thus resulting in no behavioral differences between APOE-groups during the performance of a VFT.}, language = {en} } @article{DollVonaSchnappetal.2020, author = {Doll, Julia and Vona, Barbara and Schnapp, Linda and R{\"u}schendorf, Franz and Khan, Imran and Khan, Saadullah and Muhammad, Noor and Alam Khan, Sher and Nawaz, Hamed and Khan, Ajmal and Ahmad, Naseer and Kolb, Susanne M. and K{\"u}hlewein, Laura and Labonne, Jonathan D. J. and Layman, Lawrence C. and Hofrichter, Michaela A. H. and R{\"o}der, Tabea and Dittrich, Marcus and M{\"u}ller, Tobias and Graves, Tyler D. and Kong, Il-Keun and Nanda, Indrajit and Kim, Hyung-Goo and Haaf, Thomas}, title = {Genetic Spectrum of Syndromic and Non-Syndromic Hearing Loss in Pakistani Families}, series = {Genes}, volume = {11}, journal = {Genes}, number = {11}, issn = {2073-4425}, doi = {10.3390/genes11111329}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219293}, year = {2020}, abstract = {The current molecular genetic diagnostic rates for hereditary hearing loss (HL) vary considerably according to the population background. Pakistan and other countries with high rates of consanguineous marriages have served as a unique resource for studying rare and novel forms of recessive HL. A combined exome sequencing, bioinformatics analysis, and gene mapping approach for 21 consanguineous Pakistani families revealed 13 pathogenic or likely pathogenic variants in the genes GJB2, MYO7A, FGF3, CDC14A, SLITRK6, CDH23, and MYO15A, with an overall resolve rate of 61.9\%. GJB2 and MYO7A were the most frequently involved genes in this cohort. All the identified variants were either homozygous or compound heterozygous, with two of them not previously described in the literature (15.4\%). Overall, seven missense variants (53.8\%), three nonsense variants (23.1\%), two frameshift variants (15.4\%), and one splice-site variant (7.7\%) were observed. Syndromic HL was identified in five (23.8\%) of the 21 families studied. This study reflects the extreme genetic heterogeneity observed in HL and expands the spectrum of variants in deafness-associated genes.}, language = {en} } @article{SamperAgreloSchiraHeinenBeyeretal.2020, author = {Samper Agrelo, Iria and Schira-Heinen, Jessica and Beyer, Felix and Groh, Janos and B{\"u}termann, Christine and Estrada, Veronica and Poschmann, Gereon and Bribian, Ana and Jadasz, Janusz J. and Lopez-Mascaraque, Laura and Kremer, David and Martini, Rudolf and M{\"u}ller, Hans Werner and Hartung, Hans Peter and Adjaye, James and St{\"u}hler, Kai and K{\"u}ry, Patrick}, title = {Secretome analysis of mesenchymal stem cell factors fostering oligodendroglial differentiation of neural stem cells in vivo}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {12}, issn = {1422-0067}, doi = {10.3390/ijms21124350}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285465}, year = {2020}, abstract = {Mesenchymal stem cell (MSC)-secreted factors have been shown to significantly promote oligodendrogenesis from cultured primary adult neural stem cells (aNSCs) and oligodendroglial precursor cells (OPCs). Revealing underlying mechanisms of how aNSCs can be fostered to differentiate into a specific cell lineage could provide important insights for the establishment of novel neuroregenerative treatment approaches aiming at myelin repair. However, the nature of MSC-derived differentiation and maturation factors acting on the oligodendroglial lineage has not been identified thus far. In addition to missing information on active ingredients, the degree to which MSC-dependent lineage instruction is functional in vivo also remains to be established. We here demonstrate that MSC-derived factors can indeed stimulate oligodendrogenesis and myelin sheath generation of aNSCs transplanted into different rodent central nervous system (CNS) regions, and furthermore, we provide insights into the underlying mechanism on the basis of a comparative mass spectrometry secretome analysis. We identified a number of secreted proteins known to act on oligodendroglia lineage differentiation. Among them, the tissue inhibitor of metalloproteinase type 1 (TIMP-1) was revealed to be an active component of the MSC-conditioned medium, thus validating our chosen secretome approach.}, language = {en} } @article{BeyerJadaszSamperAgreloetal.2020, author = {Beyer, Felix and Jadasz, Janusz and Samper Agrelo, Iria and Schira-Heinen, Jessica and Groh, Janos and Manousi, Anastasia and B{\"u}termann, Christine and Estrada, Veronica and Reiche, Laura and Cantone, Martina and Vera, Julio and Vigan{\`o}, Francesca and Dimou, Leda and M{\"u}ller, Hans Werner and Hartung, Hans-Peter and K{\"u}ry, Patrick}, title = {Heterogeneous fate choice of genetically modulated adult neural stem cells in gray and white matter of the central nervous system}, series = {Glia}, volume = {68}, journal = {Glia}, number = {2}, doi = {10.1002/glia.23724}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218566}, pages = {393 -- 406}, year = {2020}, abstract = {Apart from dedicated oligodendroglial progenitor cells, adult neural stem cells (aNSCs) can also give rise to new oligodendrocytes in the adult central nervous system (CNS). This process mainly confers myelinating glial cell replacement in pathological situations and can hence contribute to glial heterogeneity. Our previous studies demonstrated that the p57kip2 gene encodes an intrinsic regulator of glial fate acquisition and we here investigated to what degree its modulation can affect stem cell-dependent oligodendrogenesis in different CNS environments. We therefore transplanted p57kip2 knockdown aNSCs into white and gray matter (WM and GM) regions of the mouse brain, into uninjured spinal cords as well as in the vicinity of spinal cord injuries and evaluated integration and differentiation in vivo. Our experiments revealed that under healthy conditions intrinsic suppression of p57kip2 as well as WM localization promote differentiation toward myelinating oligodendrocytes at the expense of astrocyte generation. Moreover, p57kip2 knockdown conferred a strong benefit on cell survival augmenting net oligodendrocyte generation. In the vicinity of hemisectioned spinal cords, the gene knockdown led to a similar induction of oligodendroglial features; however, newly generated oligodendrocytes appeared to suffer more from the hostile environment. This study contributes to our understanding of mechanisms of adult oligodendrogenesis and glial heterogeneity and further reveals critical factors when considering aNSC mediated cell replacement in injury and disease.}, language = {en} } @article{MuellerMetaMeidneretal.2023, author = {M{\"u}ller, Patrick and Meta, Mergim and Meidner, Jan Laurenz and Schwickert, Marvin and Meyr, Jessica and Schwickert, Kevin and Kersten, Christian and Zimmer, Collin and Hammerschmidt, Stefan Josef and Frey, Ariane and Lahu, Albin and de la Hoz-Rodr{\´i}guez, Sergio and Agost-Beltr{\´a}n, Laura and Rodr{\´i}guez, Santiago and Diemer, Kira and Neumann, Wilhelm and Gonz{\`a}lez, Florenci V. and Engels, Bernd and Schirmeister, Tanja}, title = {Investigation of the compatibility between warheads and peptidomimetic sequences of protease inhibitors — a comprehensive reactivity and selectivity study}, series = {International Journal of Molecular Sciences}, volume = {24}, journal = {International Journal of Molecular Sciences}, number = {8}, issn = {1422-0067}, doi = {10.3390/ijms24087226}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313596}, year = {2023}, abstract = {Covalent peptidomimetic protease inhibitors have gained a lot of attention in drug development in recent years. They are designed to covalently bind the catalytically active amino acids through electrophilic groups called warheads. Covalent inhibition has an advantage in terms of pharmacodynamic properties but can also bear toxicity risks due to non-selective off-target protein binding. Therefore, the right combination of a reactive warhead with a well-suited peptidomimetic sequence is of great importance. Herein, the selectivities of well-known warheads combined with peptidomimetic sequences suited for five different proteases were investigated, highlighting the impact of both structure parts (warhead and peptidomimetic sequence) for affinity and selectivity. Molecular docking gave insights into the predicted binding modes of the inhibitors inside the binding pockets of the different enzymes. Moreover, the warheads were investigated by NMR and LC-MS reactivity assays against serine/threonine and cysteine nucleophile models, as well as by quantum mechanics simulations.}, language = {en} }