Cardiac Shock Wave Therapy Attenuates Cardiomyocyte Apoptosis after Acute Myocardial Infarction in Rats

Abstract

Background/Aims: Researches have showed that cardiac shock wave therapy (CSWT) could improve left ventricular function and attenuate LV remodeling of the ischemic heart. Apoptosis plays an important role in myocardial infarction and determines heart function and prognosis. However, it is still not clear whether CSWT is sufficient to attenuate acute myocardial infarction (AMI) induced cardiomyocyte apoptosis in vivo. In this study, we used a rat model to examine whether CSWT could attenuate cardiomyocyte apoptosis after AMI and to explore potential mechanisms. Methods: We generated an AMI rat model to investigate the function and possible regulatory mechanisms of CSWT. All rats were randomly divided into four groups: the sham-operated only group, sham-operated with SW treatment group, AMI only group, and AMI treated with SW treatment group.The rats were treated with a left anterior descending coronary artery ligation for 12h and then treated with or without CSWT (800 shots at 0.1 mJ/ mm2). Cytochrome c release was measured to analyze mitochondrial function and integrity. The apoptotic cell rate was determined by TUNEL assay. Western blot was used to analyze the cell apoptosis-, inflammation-, and survival-related signaling pathways. Results: First, the methodology of CSWT in the rat model of AMI was established. Second, CSWT attenuated the cardiomyocyte apoptosis rate in the infarct border zone. Third, CSWT suppressed the expression of apoptosis and inflammation molecules after AMI. Fourth, CSWT inhibited activation of the JNK pathway, which indicated inhibition of the cell inflammatory pathways and promotion of cardiomyocyte survival after AMI. Conclusion: These results indicate that CSWT exerts a protective effect against AMI-induced cardiomyocyte apoptosis, potentially by attenuating cytochrome c release from the mitochondria and inhibiting of the mitochondrial-dependent intrinsic apoptotic pathway. We also demonstrate that CSWT suppresses the JNK pathway and cardiomyocyte inflammation, which may also decrease cardiomyocyte apoptosis in vivo.