花旗松素通过激活Nrf2/HO-1/HIF1α/Autophagy信号通路对H2O2所致H9C2细胞氧化应激保护作用的研究

Taxifolin Protects H_2O_2-induced Myocardial Oxidative Stress via Activation of Nrf2/HO-1/HIF1α/Autophagy Pathway in H9C2 Cells

氧化应激(oxidative stress,OS)是缺血性心肌病(ischemic cardiomyopathy,ICM)的主要发病机制之一,抗氧化应激损伤是防治缺血性心肌病的关键。为了探讨花旗松素(taxifolin,tax)对过氧化氢(hydrogen peroxide,H_2O_2)诱导的大鼠心肌细胞H9C2氧化应激的影响及其可能的分子机制,将培养的H9C2心肌细胞随机分为对照组(Control)、氧化应激组(H_2O_2)、tax预处理组(tax+H_2O_2)、tax单独处理组(tax)。通过观察细胞形态的改变,检测细胞内活性氧(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)的生成、自噬体自噬泡的形成,以及自噬(autophagy)相关蛋白质LC3 I/II、p62的表达,验证tax对氧化应激及自噬的影响。同时,通过检测Nrf2、HO-1、HIF1α的表达,研究可能存在的分子机制。研究发现tax可缓解H_2O_2诱导的H9C2细胞氧化应激,表现为细胞肥大形态缓解、ROS生成降低、MDA产生减少,而且Nrf2/HO-1/HIF1α蛋白的表达升高,自噬水平升高。实验结果表明:tax可能通过激活Nrf2/HO-1/HIF1α/Autophagy信号通路促进自噬及抗氧化应激,从而发挥心肌保护作用。

Oxidative stress is one of the main pathogenesis is an important prevention strategy. In order to investigate of ischemic cardiomyopathy （IGM）, and antioxidant the effects and mechanisms of taxifolin （tax） on the H202 induced oxidative stress, H9C2 cells were pretreated with/without tax （100 μmol/mL） for 6 h, and then ex- posed to hypoxia in the presence/absence of 200 μmol/mL H202 for the next 12 h. Oxidative stress level and autophagy phenomenon were evaluated by planar morphology, intracellular reactive oxygen species （ROS） and malondialdehyde （MDA） generation, autophagosome and phagophore formation, and autophagy related pro- teins p62 and LC3 Ⅰ/Ⅱ expression levels. In order to reveal the possible molecular mechanisms, the expression levels of nuclear factor erythroid 2-related factor （Nrf2）, hemeoxygenase-1 （HO-1）, hypoxia-inducible fac-tor lα （HIF1α） were analyzed. The results showed that H2O2-induced H9C2 myocardial hypertrophy was in- hibited by tax. At the same time, ROS and MDA productions were attenuated, Nrf2, HO-1 and HIF1α ex- pressions were upregulated, and autophagy was promoted. In conclusion, the data suggests tax protects H9C2 ceils from H202 induced oxidative stress via activation of Nrf2/HO-1/HIF1α/Autophagy pathway.