Double-edged role of the CXCL12/CXCR4 axis in experimental myocardial infarction

Elisa A. Liehn, Nancy Tuchscheerer, Isabella Kanzler, Maik Drechsler, Line Fraemohs, Alexander Schuh, Rory R. Koenen, Simone Zander, Oliver Soehnlein, Mihail Hristov, Gabriela Grigorescu, Andreea O. Urs, Mircea Leabu, Ilie Bucur, Marc W. Merx, Alma Zernecke, Josef Ehling, Felix Gremse, Twan Lammers, Fabian KiesslingJrgen Bernhagen, Andreas Schober, Christian Weber*

*Kontaktforfatter

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

Objectives: Here we assess the intrinsic functions of the chemokine receptor CXCR4 in remodeling after myocardial infarction (MI) using Cxcr4 heterozygous (Cxcr4) mice. Background: Myocardial necrosis triggers complex remodeling and inflammatory changes. The chemokine CXCL12 has been implicated in protection and therapeutic regeneration after MI through recruiting angiogenic outgrowth cells, improving neovascularization and cardiac function, but the endogenous role of its receptor CXCR4 is unknown. Methods: MI was induced by ligation of the left descending artery. Langendoff perfusion, echocardiography, quantitative immunohistochemistry, flow cytometry, angiogenesis assays, and cardiomyocyte analysis were performed. Results: After 4 weeks, infarct size was reduced in Cxcr4 mice compared with wild-type mice and in respective bone marrow chimeras compared with controls. This was associated with altered inflammatory cell recruitment, decreased neutrophil content, delayed monocyte infiltration, and a predominance of Gr1 low over classic Gr1 high monocytes. Basal coronary flow and its recovery after MI were impaired in Cxcr4mice, paralleled by reduced angiogenesis, myocardial vessel density, and endothelial cell count. Notably, no differences in cardiac function were seen in Cxcr4mice compared with wild-type mice. Despite defective angiogenesis, Cxcr4 mouse hearts showed no difference in CXCL12, vascular endothelial growth factor or apoptosis-related gene expression. Electron microscopy revealed lipofuscin-like lipid accumulation in Cxcr4 mouse hearts and analysis of lipid extracts detected high levels of phosphatidylserine, which protect cardiomyocytes from hypoxic stress in vitro. Conclusions: CXCR4 plays a crucial role in endogenous remodeling processes after MI, contributing to inflammatory/progenitor cell recruitment and neovascularization, whereas its deficiency limits infarct size and causes adaptation to hypoxic stress. This should be carefully scrutinized when devising therapeutic strategies involving the CXCL12/CXCR4 axis.

OriginalsprogEngelsk
TidsskriftJournal of the American College of Cardiology
Vol/bind58
Udgave nummer23
Sider (fra-til)2415-2423
ISSN0735-1097
DOI
StatusUdgivet - 29. nov. 2011
Udgivet eksterntJa

Bibliografisk note

Funding Information:
This study was supported by the Deutsche Forschungsgemeinschaft (FOR809, IRTG 1508 EuCAR) and IZKF (NTV 113-c, TV113-d) within the faculty of Medicine at RWTH Aachen University.

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