Grx1抑制高糖诱导的H9c2细胞中Caspase-8/3和JNK/c-Jun凋亡通路的激活

Glutaredoxin 1 Suppresses the Apoptotic Signal Pathway of Caspase-8/3 and JNK/c-Jun in H9c2 Cell Induced by High Glucose

谷氧还蛋白1(glutaredoxin 1,Grx1)作为一种重要的抗氧化剂,通过响应多种重要蛋白质的活动和功能调节细胞的关键过程.了解Grx1功能,对寻求糖尿病和心肌病等,以凋亡失调和氧化还原稳态改变为发病机制的疾病的新颖治疗策略至关重要.为研究Grx1对高糖诱导的大鼠心肌细胞凋亡的抑制作用及相关信号机制,本研究以高糖诱导大鼠心肌细胞H9c2建立高糖损伤模型,采用免疫印迹实验检测caspase-3、8、9蛋白活性片段的表达和凋亡信号蛋白JNK/c-Jun的磷酸化水平.结果显示,与正常对照组相比,高糖组caspase家族中,剪切的caspase-3、caspase-8、caspase-9相对含量均显著增多,JNK和c-Jun蛋白的磷酸化水平均显著上调.但给予外源性Grx1保护后,剪切的caspase-3和caspase-8相对含量均显著降低,JNK和c-Jun蛋白的磷酸化水平均显著下调.上述结果表明,高糖通过介导caspase-8/3和caspase-9/3凋亡通路,并激活凋亡相关信号通路JNK/c-Jun诱导H9c2心肌细胞凋亡.给予外源性Grx1保护后,可通过抑制caspase-8/3凋亡通路和JNK/c-Jun信号通路的激活,拮抗高糖诱导的心肌细胞凋亡.

Glutaredoxin 1 （Grx1） is the primary antioxidant enzyme responsible for activity and function of many important proteins in regulation of critical cellular processes. Knowledge of the effects of Grx1 is essential for developing novel therapeutic approaches for treating diseases involving dysregulated apoptosis, such as heart disease and diabetes diseases, where alterations in redox homeostasis are hallmarks for pathogenesis. In order to investigate the role of Grx 1 resisting cardiocyte apoptosis induced by high glucose and signaling mechanism, the activation of caspase-8, caspase-9 and caspase-3 proteins and phosphorylation level of JNK/c-Jun were tested by Western blot assay respectively in H9c2 induced by high glucose. The results showed that the activation of cleaved caspase-8, caspase-9 and caspase-3 proteins, and phosphorylation level of JNK/c-Jun were upregulated respectively by treatment with high glucose alone，but the activation of cleaved caspase-8 and caspase-3, and phosphorylation level of JNK/c-Jun were reduced by cotreatment with Grx1 and high glucose. The results indicate that the activation of caspase-8, caspase-9 and caspase-3 proteins and phosphorylation level of JNK/c-Jun were involved in H9c2 cardiocyte apoptosis induced by high glucose. The mechanism of Grx 1 resisting cardiocyte apoptosis induced by high glucose is associated with suppressing the apoptotic signal pathway of caspase-8/3 and JNK /c-Jun.