Julie Gardener
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CB2 cannabinoid receptor activation is cardioprotective in a mouse model of ischemia/reperfusion
Fabrizio Montecuccoa, Sébastien Lengleta, Vincent Braunersreuthera, Fabienne Burgera, Graziano Pellia, Maria Bertolottob, François Macha and Sabine Steffensa, , a Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University Hospital, Geneva, Switzerland
b Clinic of Internal Medicine I, Department of Internal Medicine, University of Genoa, Italy
Received 20 October 2008; revised 18 December 2008; accepted 18 December 2008. Available online 7 January 2009.
Journal of Molecular and Cellular Cardiology
Volume 46, Issue 5, May 2009, Pages 612-620
Abstract
Preventive treatment with cannabinoid agonists has been reported to reduce the infarct size in a mouse model of myocardial ischemia/reperfusion. Here we investigated the possible cardioprotective effect of selective CB2 cannabinoid receptor activation during ischemia. We performed left coronary artery ligature in C57Bl/6 mice for 30 min, followed by 24 h of reperfusion. Five minutes before reperfusion, mice received intraperitoneal injection of the CB2 selective agonist JWH-133 (20 mg/kg) or vehicle. Infarct size was assessed histologically and by cardiac troponin I (cTnI) ELISA. Immunohistochemical analysis of leukocyte infiltration, oxidative stress in situ quantification, real-time RT-PCR analysis of inflammatory mediators as well as western blots for kinase phosphorylation was also performed. In addition, we studied chemotaxis and integrin expression of human neutrophils in vitro. JWH-133 significantly reduced the infarct size (I/area at risk: 19.27% ± 1.91) as compared to vehicle-treated mice (31.77% ± 2.7). This was associated with a reduction of oxidative stress and neutrophil infiltration in the infarcted myocardium, whereas activation of ERK 1/2 and STAT-3 was increased. Preinjection of PI3K inhibitor LY294002, MEK 1/2 inhibitor U0126 and JAK-2 inhibitor AG-490 partially abrogated the JWH-133 mediated infarct size reduction. No changes in cardiac CXCL1, CXCL2, CCL3, TNF-α, and ICAM-1 expression levels were found. Furthermore, JWH-133 inhibited the TNF-α induced chemotaxis and integrin CD18/CD11b (Mac-1) upregulation on human neutrophils. Our data suggest that JWH-133 administration during ischemia reduces the infarct size in a mouse model of myocardial ischemia/reperfusion through a direct cardioprotective activity on cardiomyocytes and neutrophils.
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