Transplanted Human Amniotic Epithelial Cells Secrete Paracrine Proangiogenic Cytokines in Rat Model of Myocardial Infarction.

Human amniotic epithelial cells (h-AECs) have been shown to differentiate into cardiomyocyte-like cells in vivo that can regenerate myocardial tissue and improve cardiac function in a rat model of myocardial infarction (MI). In this study, we investigated the paracrine factors released from h-AECs under hypoxic conditions to elucidate the possible mechanisms underlying this previously reported phenomenon of h-AEC-mediated cardiac repair. We used hypoxic cell culture conditions to simulate myocardial infarction in vitro. In comparison to normal conditions, we found that h-AECs secreted higher levels of several cytokines, including angiogenin (ANG), epidermal growth factor (EGF), interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1. To determine whether transplanted h-AECs express these proangiogenic cytokines in vivo, we ligated the coronary artery of rats to cause MI and injected either h-AECs or saline into the infarcted area. We found that the infarct and border zones of rat myocardium treated with h-AECs had higher expression levels of the human-origin cytokines ANG, EGF, IL-6, and MCP-1 compared to the tissues of saline-treated rats. In conclusion, h-AECs secreted proangiogenic cytokines in a rat model of MI, which may suggest that the paracrine effect by h-AECs could regenerate myocardial tissue and improve cardiac function.