Yi Mai granule improve energy supply of endothelial cells in atherosclerosis via miRNA-125a-5p regulating mitochondrial autophagy through Pink1-Mfn2-Parkin pathway

Yi Mai granule (YMG) consists of two classic Chinese medicine formulas used to treat cardiovascular disease for centuries. The Pink1-Mfn2-Parkin pathway, a well-recognized mechanism that mediates mitochondrial autophagy, plays a big part in mitochondrial quality control and the maintenance of heart function. However, the effects of YMG on endothelial dysfunction and mitochondrial autophagy remain unknown.Here, we focused on the therapeutic effects of YMG in improving mitochondrial autophagy and the mechanism of YMG against cardiovascular disease.In this study, rats were fed high-fat diet (HFD) for 21 weeks and were given high, medium, and low doses of YMG in stomach. The open field test was used to evaluate the rats' behavior. Atherosclerotic plaques, blood lipids, and cytokine levels were measured. Mitochondrial autophagy changes were observed by Transmission electron microscope (TEM). Human umbilical vein endothelial cells (HUVECs) were injured by angiotensinⅡ(AngⅡ) and were given high, medium, and low doses of YMG medicated serum in cell culture medium. Pink1-Mfn2-Parkin expression and miRNA 125a-5p expression were measured by RT-PCR and Western blot.We demonstrated that the atherosclerosis model group tended to exhibit reduced vitality behaviors. We proved that the atherosclerosis model group showed obvious atherosclerotic plaques, endothelial cells destruction, and high level of blood lipid and cytokines (including hs-CRP, ET). Mitochondria were reduced, and mitophagy was inhibited in aortic cells of the model group. MiRNA-125a-5p was up-regulated; at the same time, Pink1-Mfn2-Parkin-mediated mitochondrial autophagy was prevented. We also proved that AngⅡinjured HUVEC showed obviously low mRNA levels of Pink1, Mfn2, and Parkin. Interestingly, we found that miRNA-125a-5p was significantly down regulated in Ang II-induced HUVECs. In addition, miRNA-125a-5p significantly reduced the protective effect of YiMai Granules against Ang II injury.Our finding indicated that Pink1-Mfn2-Parkin-mediated mitochondrial autophagy plays a crucial role in alleviating atherosclerosis. YMG alleviated atherosclerosis by potentially activating mitochondrial autophagy may via miRNA-125a-5p, regulating Pink1-Mfn2-Parkin pathway, and regulating proinflammatory factors, vasoconstriction cytokine, and blood lipids.