Abstract 17950: Irisin Protects the Heart Against Myocardial Ischemia and Reperfusion Injury
Introduction: Irisin has been identified as a newly identified cardiokine. However, whether irisin protects the heart against ischemia and /reperfusion (I/R) injury remains unknown.
Hypothesis: This study sought to determine the effect of irisin in the modulation of myocardial I/R injury in the mouse heart.
Methods: Adult C57/BL6 mice were injected intraperitoneally with irisin (100mg/kg) or vehicle for 30 minutes to elicit preconditioning. The hearts were isolated and subjected to 30 min ischemia /30 min reperfusion in Langendorff system. Left ventricular function and infarction size were determined. Western blot was employed to determine cellular signaling. In vitro H9c2 cardiomyoblasts were exposed to hypoxia and reoxygenation in the presence or absence of irisin (10ng/ml). Cell cytotoxicity, mitochondrial respiration, and mitochondrial permeability transition pore (mPTP) were determined.
Results: As compared to control group, irisin treatments produced remarkable improvements in left ventricular functional recovery following I/R, as evident by the increase in RPP and attenuation in LVEDP. Myocardial infarct size showed a marked decrease as compared to the control group. Irisin treatment increased SOD-1 expression and p38 phosphorylation, but suppressed active-caspase 3 and annexin V. In H9c2 cardiomyoblasts exposed to hypoxia/reoxygenation, irisin treatment resulted in a marked reduction of lactate dehydrogenase (LDH) leakage and apoptotic positive cardiomyocytes. Notably, irisin treatments improved mitochondrial respiration and inhibited the opening of mitochondrial permeability transition pores.
Conclusion: These results indicated that irisin protected the heart against I/R injury and improved mitochondrial function.
Author Disclosures: H. Wang: None. S. Zhang: None. Y.T. Zhao: None. J. Du: None. T.C. Zhao: None.
- © 2016 by American Heart Association, Inc.