Currently, there remains a great need to elucidate the molecular mechanism of acute myocardial
infarction in order to facilitate the development of novel therapy. Inhibitor of apoptosis-stimulating
protein of p53 (iASPP) is a member of the ASPP family proteins and an evolutionarily preserved
inhibitor of p53 that is involved in many cellular processes, including apoptosis of cancer cells.
The purpose of this study was to investigate the possible role of iASPP in acute myocardial infarction. The protein level of iASPP was markedly reduced in the ischemic hearts in vivo and hydrogen
peroxide-exposed cardiomyocytes in vitro. Overexpression of iASPP reduced the infarct size and
cardiomyocyte apoptosis of mice subjected to 24 h of coronary artery ligation. Echocardiography
showed that cardiac function was improved as indicated by the increase in ejection fraction and
fractional shortening. In contrast, knockdown of iASPP exacerbated cardiac injury as manifested by
impaired cardiac function, increased infarct size, and apoptosis rate. Mechanistically, overexpression of iASPP inhibited, while knockdown of iASPP increased the expressions of p53 and Bax, the
key regulators of apoptosis. Taken together, our results suggested that iASPP is an important regulator of cardiomyocyte apoptosis, which represents a potential target in the therapy of myocardial
infarction