iTRAQ-based quantitative proteomic analysis of the anti-apoptotic effect of hyperin, which is mediated by Mcl-1 and Bid, in H2O2-injured EA.hy926 cells

Endothelial injury has been implicated in the pathogenesis of many cardiovascular diseases, including thrombotic disorders. Hyperin (quercetin-3-O-galactoside), a flavonoid compound and major bioactive component of the medicinal herb Apocynum venetum L., is commonly used to prevent endothelium dysfunction. However, its mode of action remains unclear. To the best of our knowledge, we have for the first time investigated the protective effect hyperin exerts against H2O2-induced injury in human endothelium-derived EA.hy926 cells using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis. The results showed that H2O2 exposure induced alterations in the expression of 250 proteins in the cells. We noted that the expression of 52 proteins associated with processes such as cell apoptosis, cell cycle and cytoskeleton organization, was restored by hyperin treatment. Of the proteins differentially regulated following H2O2 stress, the anti-apoptotic protein, myeloid cell leukemia-1 (Mcl-1), and the pro-apoptotic protein, BH3-interacting domain death agonist (Bid), exhibited marked changes in expression. Hyperin increased Mcl-1 expression and decreased that of Bid in a dose-dependent manner. In addition, flow cytometric analysis and western blot analysis of the apoptosis-related proteins, truncated BID (tBid), cleaved caspase-3, cleaved caspase-9, Fas, FasL and caspase-8, demonstrated that the rate of apoptosis and the pro-apoptotic protein levels were decreased by hyperin pre-treatment. In the present study we demonstrate that hyperin effectively prevents H2O2-induced cell injury by regulating the Mcl-1- and Bid-mediated anti-apoptotic mechanism, suggesting that hyperin is a potential candidate for use in the treatment of thrombotic diseases.