Adipose Mesenchymal Stem Cell Exosomes Regulate Ferroptosis via ATF3 to Attenuate Acute Myocardial Infarction.

During acute myocardial infarction (AMI), ferroptosis occurs in cardiomyocytes, leading to ventricular remodeling. To investigate the influence of exosomes (Exo) derived from adipose mesenchymal stem cells (AD-MSCs) on cardiomyocytes, a therapeutic approach to resolve AMI may be discovered. The Exo of AD-MSCs was isolated and identified, and internalized into cardiomyocytes. In vitro, oxygen-sugar deprivation (OGD) was performed to cultivate H9C2 cells to simulate the AMI model, and H9C2 cells incubated with Exo. In addition, an AMI rat model was constructed, and Exo was injected into the edge of myocardial infarction. The levels of MDA, Fe2+, GSH, and GPX4 were detected using corresponding kit, the expression levels of ATF3, SLC7A11, PTGS2, and GPX4 were detected using western blot. The oe-ATF3 plasmid was transfected into H9C2 cells to explore the mechanism of ferroptosis regulation by Exo. Exo was isolated and identified successfully, and further confirmed that it could be internalized into H9C2 cells. Compared with the control group, the level of apoptosis and ferroptosis in OGD group was significantly increased, while the level of cell vitality was significantly decreased. After Exo treatment, the level of ferroptosis and apoptosis was significantly decreased, while the level of cell vitality was significantly increased. However, after overexpression of ATF3 in cells, it was found that the ferroptosis level down-regulated by Exo was reversed. Further examination of the SLC7A11/Xct system showed that ATF3 could inhibit the expression of SLC7A11. In addition, compared with the AMI+PBS group, the infarct size of the AMI+Exo group was significantly reduced, and the level of cardiomyocyte apoptosis and ferroptosis was also significantly improved. Exo derived from AD-MSCs can inhibit the expression of ATF3, promote the transport of Fe2+ by SLC7A11/Xct system, thus inhibiting the ferroptosis of myocardial cells in AMI, increasing the activity of myocardial cells, and playing a role in alleviating AMI.