Krüppel-Like Factor 15 Reduces Ischemia-Induced Apoptosis Involving Regulation of p38/MAPK Signaling.

Cardiomyocyte apoptosis is a characteristic of a variety of cardiac diseases, including myocardial infarction (MI). Krüppel-like factor 15 (KLF15) is a transcription factor of Krüppel family that plays an important part in cardiovascular diseases. However, the function and the underlying mechanism of KLF15 in MI remain unknown. The expression of KLF15 was downregulated both in ischemic myocardium of MI mice model and hypoxia-treated neonatal rat ventricular myocytes (NRVCs). KLF15 overexpression mediated by adeno-associated virus significantly abrogated the ischemia-induced cardiac dysfunction, increased the survival rate, and reduced infarct size after MI. Meanwhile, KLF15 overexpression dramatically reduced the myocardial apoptosis, regulated apoptosis-related genes, such as Bcl2 and Bax, diminished the activities of caspase-9/3, and inactivated p38/MAPK signaling in the border zone. Similar results were observed in NRVCs exposed to hypoxia. We demonstrated for the first time that KLF15 overexpression could reduce cardiomyocyte apoptosis and improve cardiac dysfunction in MI mice at least partially by inhibiting p38/MAPK signaling pathway.