@phdthesis{Lang2013, author = {Lang, Katharina}, title = {Selektive Aldosteronsynthaseinhibitoren in der funktionellen Bildgebung zur Differenzialdiagnose des Prim{\"a}ren Hyperaldosteronismus - Entwicklung eines Testsystems und Evaluation geeigneter Substanzen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-108693}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {5 - 13\% aller Hypertoniker leiden an einem Prim{\"a}ren Hyperaldosteronismus (PA), was diese Erkrankung zu der h{\"a}ufigsten Form sekund{\"a}rer Hypertonie macht. Die Subtypdifferenzierung dient der Unterscheidung zwischen unilateraler, operativ zu therapierender und bilateraler, medikament{\"o}s zu therapierender Form. Der diagnostische Goldstandard in der Subtypdifferenzierung, der selektive Nebennierenvenenkatheter, ist aufgrund seiner Limitationen immer wieder Gegenstand kontroverser Diskussionen. W{\"a}hrend CT- und MRT- Bildgebung einen fester Bestandteil der Stufendiagnostik des PA darstellen, hat die funktionelle Bildgebung, PET und SPECT, hierbei noch keinen festen Platz. In der bildgebenden Darstellung der Nebennieren allgemein gewinnen diese Verfahren, vor allem auf der Basis von Etomidat und seinen Derivaten, zunehmend an Bedeutung. Beipiele hierf{\"u}r sind 11C- Meto- bzw. 18F- FETO- PET und 123I- IMTO- SPECT. Relativ neu in der Entwicklung sind selektive Aldosteronsynthaseinhibitoren. Problematisch hierbei ist die 93\% Homologie in der Aminos{\"a}uresequenz von CYP11B1 und CYP11B2, der Aldosteronsynthase. Die dieser Arbeit zugrunde liegende Idee ist die Entwicklung eines funktionellen Bildgebungsverfahrens zur Differenzialdiagnose des PA auf der Basis fluorierter und iodierter Aldosteronsynthasenhibitoren. Mittels Realtime- PCR konnte gezeigt werden, dass die {\"U}berexpression von CYP11B2 in aldosteronproduzierenden Tumoren dieses Enzym zu einem geeigneten Ansatzpunkt f{\"u}r radioaktiv markierte Tracer macht. Zur Evaluation geeigneter Substanzen wurde daher eine, humanes CYP11B1 bzw. CYP11B2 stabil exprimierende Zelllinie auf Basis der murinen Y1- Nebennierenrindenkarzinom- Zellen, entwickelt. Dies gelang durch Klonierung der humanen Enzyme in den pcDNA3.1zeo(+)- Vektor und anschließende Transfektion mit Lipofectamine. Zur weiteren Substanztestung wurde jeweils der Klon mit hoher Expression der CYP11B Enzyme auf mRNA- und Proteinebene bei gleichzeitig h{\"o}chster Hormonkonzentration im Zellkultur{\"u}berstand ausgew{\"a}hlt. Inkubation dieser Zelllinien mit den CYP11B- Inhibitoren Etomidat und Metomidat erbrachte IC50- Werte im nanomolekularen Bereich. In dem Testsystem stellte sich das fluorierte Naphthenylpyridin- Derivat 5.1 als potentester und zugleich sehr selektiver Inhibitor von CYP11B2 heraus, der erst ab einer Zehnerpotenz {\"u}ber der ermittelten IC50 einen signifikanten antiproliferativen Effekt auf NCI- H295 Zellen aus{\"u}bte. Die stabil transfizierten Y1-CYP11B Zellen stellten sich als geeignetes Testsystem zur Evaluation von Potenz und Selektivit{\"a}t der Aldosteronsynthase- Inhibitoren heraus. Mit der Substanz 5.1 konnte bereits ein potenter und selektiver Inhibitor von CYP11B2 entwickelt werden. Der IC50- Wert f{\"u}r die Inhibition von CYP11B2 lag f{\"u}r diese Substanz aber noch etwa um den Faktor 100 h{\"o}her als f{\"u}r die Referenzsubstanz Etomidat, so dass die Entwicklung und Testung weiterer Inhibitoren folgen muss, bis eine geeignete Substanz f{\"u}r die funktionale Bildgebung zur Differenzialdiagnose des PA gefunden ist.}, subject = {Diagnostik / Bildgebendes Verfahren}, language = {de} } @article{SbieraRonchiLeichetal.2013, author = {Sbiera, Silviu and Ronchi, Cristina L. and Leich, Ellen and Henzel, Katharina and Rosenwald, Andreas and Allolio, Bruno and Fassnacht, Martin}, title = {Single Nucleotide Polymorphism Array Profiling of Adrenocortical Tumors - Evidence for an Adenoma Carcinoma Sequence?}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0073959}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97218}, year = {2013}, abstract = {Adrenocortical tumors consist of benign adenomas and highly malignant carcinomas with a still incompletely understood pathogenesis. A total of 46 adrenocortical tumors (24 adenomas and 22 carcinomas) were investigated aiming to identify novel genes involved in adrenocortical tumorigenesis. High-resolution single nucleotide polymorphism arrays (Affymetrix) were used to detect copy number alterations (CNAs) and copy neutral losses of heterozygosity (cnLOH). Genomic clustering showed good separation between adenomas and carcinomas, with best partition including only chromosome 5, which was highly amplified in 17/22 malignant tumors. The malignant tumors had more relevant genomic aberrations than benign tumors, such as a higher median number of recurrent CNA (2631 vs 94), CNAs >100 Kb (62.5 vs 7) and CN losses (72.5 vs 5.5), and a higher percentage of samples with cnLOH (91\% vs 29\%). Within the carcinoma cohort, a precise genetic pattern (i.e. large gains at chr 5, 7, 12, and 19, and losses at chr 1, 2, 13, 17, and 22) was associated with a better prognosis (overall survival: 72.2 vs 35.4 months, P=0.063). Interestingly, >70\% of gains frequent in beningn were also present in malignant tumors. Notch signaling was the most frequently involved pathway in both tumor entities. Finally, a CN gain at imprinted "IGF2" locus chr 11p15.5 appeared to be an early alteration in a multi-step tumor progression, followed by the loss of one or two alleles, associated with increased IGF2 expression, only in carcinomas. Our study serves as database for the identification of genes and pathways, such as Notch signaling, which could be involved in the pathogenesis of adrenocortical tumors. Using these data, we postulate an adenoma-carcinoma sequence for these tumors.}, language = {en} } @article{FrantzKlaiberBabaetal.2013, author = {Frantz, Stefan and Klaiber, Michael and Baba, Hideo A. and Oberwinkler, Heinz and V{\"o}lker, Katharina and Gaßner, Birgit and Bayer, Barbara and Abeßer, Marco and Schuh, Kai and Feil, Robert and Hofmann, Franz and Kuhn, Michaela}, title = {Stress-dependent dilated cardiomyopathy in mice with cardiomyocyte-restricted inactivation of cyclic GMP-dependent protein kinase I}, series = {European Heart Journal}, volume = {34}, journal = {European Heart Journal}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134693}, pages = {1233-1244}, year = {2013}, abstract = {Aims: Cardiac hypertrophy is a common and often lethal complication of arterial hypertension. Elevation of myocyte cyclic GMP levels by local actions of endogenous atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) or by pharmacological inhibition of phosphodiesterase-5 was shown to counter-regulate pathological hypertrophy. It was suggested that cGMP-dependent protein kinase I (cGKI) mediates this protective effect, although the role in vivo is under debate. Here, we investigated whether cGKI modulates myocyte growth and/or function in the intact organism. Methods and results: To circumvent the systemic phenotype associated with germline ablation of cGKI, we inactivated the murine cGKI gene selectively in cardiomyocytes by Cre/loxP-mediated recombination. Mice with cardiomyocyte-restricted cGKI deletion exhibited unaltered cardiac morphology and function under resting conditions. Also, cardiac hypertrophic and contractile responses to β-adrenoreceptor stimulation by isoprenaline (at 40 mg/kg/day during 1 week) were unaltered. However, angiotensin II (Ang II, at 1000 ng/kg/min for 2 weeks) or transverse aortic constriction (for 3 weeks) provoked dilated cardiomyopathy with marked deterioration of cardiac function. This was accompanied by diminished expression of the \([Ca^{2+}]_i\)-regulating proteins SERCA2a and phospholamban (PLB) and a reduction in PLB phosphorylation at Ser16, the specific target site for cGKI, resulting in altered myocyte \(Ca^{2+}_i\) homeostasis. In isolated adult myocytes, CNP, but not ANP, stimulated PLB phosphorylation, \(Ca^{2+}_i\)-handling, and contractility via cGKI. Conclusion: These results indicate that the loss of cGKI in cardiac myocytes compromises the hypertrophic program to pathological stimulation, rendering the heart more susceptible to dysfunction. In particular, cGKI mediates stimulatory effects of CNP on myocyte \(Ca^{2+}_i\) handling and contractility.}, language = {en} } @article{DoerhoeferLammertKraneetal.2013, author = {D{\"o}rh{\"o}fer, Lena and Lammert, Alexander and Krane, Vera and Gorski, Mathias and Banas, Bernhard and Wanner, Christoph and Kr{\"a}mer, Bernhard K. and Heid, Iris M. and B{\"o}ger, Carsten A.}, title = {Study design of DIACORE (DIAbetes COhoRtE) - a cohort study of patients with diabetes mellitus type 2}, series = {BMC Medical Genetics}, volume = {14}, journal = {BMC Medical Genetics}, number = {25}, issn = {1471-2350}, doi = {10.1186/1471-2350-14-25}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122040}, year = {2013}, abstract = {Background: Diabetes mellitus type 2 (DM2) is highly associated with increased risk for chronic kidney disease (CKD), end stage renal disease (ESRD) and cardiovascular morbidity. Epidemiological and genetic studies generate hypotheses for innovative strategies in DM2 management by unravelling novel mechanisms of diabetes complications, which is essential for future intervention trials. We have thus initiated the DIAbetes COhoRtE study (DIACORE). Methods: DIACORE is a prospective cohort study aiming to recruit 6000 patients of self-reported Caucasian ethnicity with prevalent DM2 for at least 10 years of follow-up. Study visits are performed in University-based recruiting clinics in Germany using standard operating procedures. All prevalent DM2 patients in outpatient clinics surrounding the recruiting centers are invited to participate. At baseline and at each 2-year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized online questionnaire and physical examination to determine incident micro-and macrovascular DM2 complications, malignancy and hospitalization, with a primary focus on renal events. Confirmatory outcome information is requested from patient records. Blood samples are obtained for a centrally analyzed standard laboratory panel and for biobanking of aliquots of serum, plasma, urine, mRNA and DNA for future scientific use. A subset of the cohort is subjected to extended phenotyping, e. g. sleep apnea screening, skin autofluorescence measurement, non-mydriatic retinal photography and non-invasive determination of arterial stiffness. Discussion: DIACORE will enable the prospective evaluation of factors involved in DM2 complication pathogenesis using high-throughput technologies in biosamples and genetic epidemiological studies.}, language = {en} } @article{ChopraLangSalzmannetal.2013, author = {Chopra, Martin and Lang, Isabell and Salzmann, Steffen and Pachel, Christina and Kraus, Sabrina and B{\"a}uerlein, Carina A. and Brede, Christian and Jord{\´a}n Garrote, Ana-Laura and Mattenheimer, Katharina and Ritz, Miriam and Schwinn, Stefanie and Graf, Carolin and Sch{\"a}fer, Viktoria and Frantz, Stefan and Einsele, Hermann and Wajant, Harald and Beilhack, Andreas}, title = {Tumor Necrosis Factor Induces Tumor Promoting and Anti-Tumoral Effects on Pancreatic Cancer via TNFR1}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97246}, year = {2013}, abstract = {Multiple activities are ascribed to the cytokine tumor necrosis factor (TNF) in health and disease. In particular, TNF was shown to affect carcinogenesis in multiple ways. This cytokine acts via the activation of two cell surface receptors, TNFR1, which is associated with inflammation, and TNFR2, which was shown to cause anti-inflammatory signaling. We assessed the effects of TNF and its two receptors on the progression of pancreatic cancer by in vivo bioluminescence imaging in a syngeneic orthotopic tumor mouse model with Panc02 cells. Mice deficient for TNFR1 were unable to spontaneously reject Panc02 tumors and furthermore displayed enhanced tumor progression. In contrast, a fraction of wild type (37.5\%), TNF deficient (12.5\%), and TNFR2 deficient mice (22.2\%) were able to fully reject the tumor within two weeks. Pancreatic tumors in TNFR1 deficient mice displayed increased vascular density, enhanced infiltration of CD4+ T cells and CD4+ forkhead box P3 (FoxP3)+ regulatory T cells (Treg) but reduced numbers of CD8+ T cells. These alterations were further accompanied by transcriptional upregulation of IL4. Thus, TNF and TNFR1 are required in pancreatic ductal carcinoma to ensure optimal CD8+ T cell-mediated immunosurveillance and tumor rejection. Exogenous systemic administration of human TNF, however, which only interacts with murine TNFR1, accelerated tumor progression. This suggests that TNFR1 has basically the capability in the Panc02 model to trigger pro-and anti-tumoral effects but the spatiotemporal availability of TNF seems to determine finally the overall outcome.}, language = {en} } @phdthesis{Witz2013, author = {Witz, Eva-Katharina}, title = {Verbesserung des linksventrikul{\"a}ren Remodelings durch Inhibition des Transkriptionsfaktors Nuclear Factor kappa B (NF-κB) in Makrophagen und Granulozyten}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-103828}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Nach einem Myokardinfarkt werden ventrikul{\"a}res Remodeling und myokardiale Funktion unter anderem durch die ablaufenden Reaktionen des angeborenen Immunsystems beeinflusst. Von zentraler Bedeutung f{\"u}r die Regulation dieser Immunreaktion ist der Transkriptionsfaktor Nuclear Factor kappa B. Tiere, bei denen NF-κB durch das Fehlen seiner Untereinheit p50 global inaktiv ist, wei- sen einen Schutz vor linksventrikul{\"a}rem Remodeling auf. Bisher ist jedoch un- klar, welche Zellen f{\"u}r diesen protektiven Effekt verantwortlich sind. Vorange- gangene Studien konnten zeigen, dass die Protektion nicht auf die fehlende NF- κB Aktivierung in Kardiomyozyten zur{\"u}ckzuf{\"u}hren ist. Aus Isch{\"a}mie- Reperfusions-Experimenten an NF-κB-defizienten Tieren ergaben sich Hinwei- se, dass v.a. die Hemmung von NF-κB in Entz{\"u}ndungszellen die protektiven Effekte vermittelt. Durch Kreuzung von LysMCre- mit lox-IKKβ-Tieren erzeugten wir Tiere, denen makrophagenspezifisch IκB-Kinase β (IKKβ) fehlt. IKK deaktiviert den Inhibitor von NF-κB und ist somit essentiell f{\"u}r eine NF-κB-Aktivierung. Als Modell der Herzinsuffizienz diente der chronische Myokardinfarkt. Die Nachbeobachtung erfolgte {\"u}ber 56 Tage. Die Knockout-Tiere (KO) hatten im Vergleich zu den Wildtyp-Tiere (WT) eine signifikant bessere {\"U}berlebensrate (KO vs. WT, 100\% vs. 49\%, p < 0,01). Pr{\"a}operativ sowie postoperativ an den Tagen 1, 21 und 56 wurden transthora- kale Echokardiographien durchgef{\"u}hrt. Bei gleicher Infarktgr{\"o}ße zeigten die KO-Tiere eine deutlich geringere linksventrikul{\"a}re Dilatation. Es konnte moleku- larbiologisch keine Reduktion der humoralen Entz{\"u}ndungsreaktion nachgewie- sen werden, ebenso blieb das Entz{\"u}ndungszellinfiltrat immunhistochemisch unver{\"a}ndert. Auch bez{\"u}glich Apoptoserate und Neovaskularisation zeigte sich kein Unterschied zwischen den Gruppen. Allerdings zeigten die LysM-IKKβ-KO-Tiere 56 Tage nach Myokardinfarkt einen deutlich erh{\"o}hten septalen Kollagen- gehalt als Hinweis auf ein ver{\"a}ndertes extrazellul{\"a}res Remodeling. Aus diesen Ergebnissen kann geschlossen werden, dass die protektiven Effek- te der globalen NF-κB-Hemmung durch die fehlende NF-κB-Aktivierung in Ma- krophagen und Granulozyten, nicht aber in Kardiomyozyten vermittelt wurden. Die durch die makrophagenspezifische NF-κB-Hemmung vermittelten Ver{\"a}nde- rungen im Remodeling der extrazellul{\"a}ren Matrix f{\"u}hren zu einer Verbesserung der {\"U}berlebensrate, besseren funktionellen Ergebnissen und einem insgesamt verminderten linksventrikul{\"a}ren Remodeling nach Myokardinfarkt.}, subject = {Remodeling}, language = {de} }