@article{BloemerPachelHofmannetal.2013, author = {Bl{\"o}mer, Nadja and Pachel, Christina and Hofmann, Urlich and Nordbeck, Peter and Bauer, Wolfgang and Mathes, Denise and Frey, Anna and Bayer, Barbara and Vogel, Benjamin and Ertl, Georg}, title = {5-Lipoxygenase facilitates healing after myocardial infarction}, series = {Basic Research in Cardiology}, volume = {108}, journal = {Basic Research in Cardiology}, number = {4}, doi = {10.1007/s00395-013-0367-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132602}, year = {2013}, abstract = {Early healing after myocardial infarction (MI) is characterized by a strong inflammatory reaction. Most leukotrienes are pro-inflammatory and are therefore potential mediators of healing and remodeling after myocardial ischemia. The enzyme 5-lipoxygenase (5-LOX) has a key role in the transformation of arachidonic acid in leukotrienes. Thus, we tested the effect of 5-LOX on healing after MI. After chronic coronary artery ligation, early mortality was significantly increased in 5-LOX\(^{-/-}\) when compared to matching wildtype (WT) mice due to left ventricular rupture. This effect could be reproduced in mice treated with the 5-LOX inhibitor Zileuton. A perfusion mismatch due to the vasoactive potential of leukotrienes is not responsible for left ventricular rupture since local blood flow assessed by magnetic resonance perfusion measurements was not different. However, after MI, there was an accentuation of the inflammatory reaction with an increase of pro-inflammatory macrophages. Yet, mortality was not changed in chimeric mice (WT vs. 5-LOX\(^{-/-}\) bone marrow in 5-LOX\(^{-/-}\) animals), indicating that an altered function of 5-LOX\(^{-/-}\) inflammatory cells is not responsible for the phenotype. Collagen production and accumulation of fibroblasts were significantly reduced in 5-LOX\(^{-/-}\) mice in vivo after MI. This might be due to an impaired migration of 5-LOX\(^{-/-}\) fibroblasts, as shown in vitro to serum. In conclusion, a lack or inhibition of 5-LOX increases mortality after MI because of healing defects. This is not mediated by a change in local blood flow, but through an altered inflammation and/or fibroblast function.}, language = {en} } @article{PachelMathesBayeretal.2013, author = {Pachel, Christina and Mathes, Denise and Bayer, Barbara and Dienesch, Charlotte and Wangorsch, Gaby and Heitzmann, Wolfram and Lang, Isabell and Ardehali, Hossein and Ertl, Georg and Dandekar, Thomas and Wajant, Harald and Frantz, Stefan}, title = {Exogenous Administration of a Recombinant Variant of TWEAK Impairs Healing after Myocardial Infarction by Aggravation of Inflammation}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0078938}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129889}, pages = {e78938}, year = {2013}, abstract = {Background: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factorinducible 14 (Fn14) are upregulated after myocardial infarction (MI) in both humans and mice. They modulate inflammation and the extracellular matrix, and could therefore be important for healing and remodeling after MI. However, the function of TWEAK after MI remains poorly defined. Methods and results: Following ligation of the left coronary artery, mice were injected twice per week with a recombinant human serum albumin conjugated variant of TWEAK (HSA-Flag-TWEAK), mimicking the activity of soluble TWEAK. Treatment with HSA-Flag-TWEAK resulted in significantly increased mortality in comparison to the placebo group due to myocardial rupture. Infarct size, extracellular matrix remodeling, and apoptosis rates were not different after MI. However, HSA-Flag-TWEAK treatment increased infiltration of proinflammatory cells into the myocardium. Accordingly, depletion of neutrophils prevented cardiac ruptures without modulating all-cause mortality. Conclusion: Treatment of mice with HSA-Flag-TWEAK induces myocardial healing defects after experimental MI. This is mediated by an exaggerated neutrophil infiltration into the myocardium.}, 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{Pachel2014, author = {Pachel, Christina Elisabeth}, title = {Entz{\"u}ndliche Faktoren und Blutpl{\"a}ttchen im experimentellen myokardialen isch{\"a}mischen Schaden}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-92565}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Die erfolgreiche therapeutische Beeinflussung pathophysiologischer Prozesse im Herzen nach myokardialem Infarkt stellt nicht zuletzt durch die steigenden Fallzahlen in der westlichen Welt und die vergleichsweise hohe Mortalit{\"a}t eine Herausforderung an Forschung und Entwicklung dar. In der vorliegenden Arbeit werden verschiedene therapeutische Strategien in klinisch relevanten Mausmodellen des Myokardinfarkts und des Isch{\"a}mie-Reperfusions-Schadens getestet. Zun{\"a}chst wird untersucht, ob sich der Einsatz des NFκB-aktivierenden Zytokins TWEAK, welches weitreichende Funktionen in physiologischen Prozessen wie Wundheilung und Entz{\"u}ndung besitzt, als eine m{\"o}gliche Therapiestrategie eignet. Die Expression von TWEAK wird nach myokardialem Infarkt stark im Herzgewebe induziert. Das gleiche gilt f{\"u}r den Rezeptor von TWEAK, Fn14, der vor allem auf kardialen Fibroblasten exprimiert wird. Daher wird angenommen, dass das TWEAK-Fn14-System am kardialen Remodelling und der Wundheilung im infarzierten Herzen beteiligt sein kann. Eine rekombinante Variante von TWEAK - HSA-Flag-TWEAK - wird im Mausmodell des Myokardinfarkts getestet. {\"U}berraschenderweise zeigt sich hierbei, dass die therapeutische Behandlung von infarzierten Versuchstieren mit diesem Protein die Mortalit{\"a}t im Vergleich zu Placebo-behandelten M{\"a}usen signifikant erh{\"o}ht. Dies geht mit einem vermehrten Auftreten an linksventrikul{\"a}ren Rupturen einher, ohne dass Defekte im kardialen Remodelling oder eine erh{\"o}hte Apoptoserate im Herzen festgestellt werden k{\"o}nnen. HSA-Flag-TWEAK bewirkt eine Erh{\"o}hung der Gewebekonzentrationen an verschiedenen pro-inflammatorischen Zytokinen (IFN-γ, IL-5, IL-12, GITR, MCP-1/-5 und RANTES) und das vermehrte Einwandern von Immunzellen in das Myokard. Hierbei ist insbesondere die stark erh{\"o}hte Infiltration an neutrophilen Granulozyten auff{\"a}llig. Ein kausaler Zusammenhang zwischen diesen Immunzellen und den auftretenden kardialen Rupturen kann durch die Depletion der Neutrophilen gezeigt werden: Nach der systemischen Applikation eines Ly6G-depletierenden Antik{\"o}rpers ist das Auftreten von kardialen Rupturen nach TWEAK-Gabe vergleichbar mit der Placebo-behandelten Infarktgruppe. Die Tatsache, dass die Mortalit{\"a}t dennoch erh{\"o}ht ist, deutet auf weitere negative Effekte durch TWEAK hin. Diese Ergebnisse legen die Vermutung nahe, dass eine Hemmung der TWEAK-Fn14-Achse positive Effekte auf die Wundheilung nach Herzinfarkt bewirken k{\"o}nnte. Als zweite Therapiestrategie wird die pharmakologische Beeinflussung verschiedener Blutpl{\"a}ttchen-spezifischer Zielstrukturen untersucht, um das Auftreten von Mikrothromben nach Myokardinfarkt zu reduzieren. Eine Hemmung {\"u}ber das Blutpl{\"a}ttchen-Glykoprotein GPVI bewirkt in dem hier eingesetzten Mausmodell der kardialen Isch{\"a}mie-Reperfusion eine signifikant verbesserte Mikrozirkulation sowie verringerte Infarktgr{\"o}ßen. GPVI stellt somit ein vielversprechendes Ziel f{\"u}r eine blutpl{\"a}ttchenhemmende Therapie nach Myokardinfarkt dar. Zusammengefasst werden in der vorliegenden Arbeit verschiedene neuartige Therapieoptionen untersucht, die die Auswirkungen isch{\"a}mischer Erkrankungen des Herzens beeinflussen k{\"o}nnen. Die Ergebnisse besitzen daher das Potenzial, zur Entwicklung neuer Therapien nach Myokardinfarkt beizutragen.}, subject = {Herzinfarkt}, language = {de} }