硫氧还蛋白-1对代谢型谷氨酸受体1a毒性的抑制作用

Protection of Thioredoxin 1 against overexpression of metabotropic glutamate receptor 1a-induced toxicity

目的研究在HEK293细胞中过表达代谢型谷氨酸受体1a(Metabotropic gluatamate receptor 1,mGluR1a),引起激动剂非依赖型细胞死亡的分子机制和硫氧还蛋白-1(Trx1)在此过程中的作用。方法采用噻唑蓝法、DCF法、免疫印迹法以及氧化还原蛋白印迹法分别检测了Trx1对细胞活力,细胞内活性氧(ROS)含量,AKT等信号通路的影响,以及Trx1本身氧化还原状态的改变。结果 HEK293细胞中过表达mGluR1a,发现ROS生成量增多,磷酸化AKT减少,PARP剪切量增多,Bcl-2表达量减少以及细胞活力降低。共转染Trx1后,可逆转上述现象。同时发现Trx1、mGluR1a之间不存在相互作用。结论在HEK293细胞中,Trx1通过清除过表达mGluR1a产生的ROS,调节相关的信号通路,从而调控过表达mG luR1a导致的细胞毒性造成的细胞死亡。本文揭示了Trx1,mGluR1a与ROS之间的一种新调节关系,以及这种关系在调控细胞生长和死亡过程中的重要意义。

Objective To understand the mechanism of underlying agonist-independent cell death induced by metabotropic glutamate receptor la（mGluR1a） overexpression and the role of Thioredoxin（Trx1） in this mechanism of cell death.Methods Cell viability,intracellular reactive oxygen species（ROS）,signaling pathways such as AKT,PARP,Bcl-2 and redox state of Trx1 were detected by MTT assay,DCF assay,Western blot and Redox western blot,respectively.Results With a decrease in cell viability,we found that ROS production as well as the splicing of PARP were augmented while the phosphorylation of AKT and the expression of an anti-apoptotic molecule,Bcl-2 were compromised in mGluR1a over-expressed HEK293 cells.We further detected the role of Trx1 in this process and found that overexpression of Trx1 could efficiently protect HEK293 cells from mGluR1a-induced cell death via its antioxidant function.In addition,the interaction of mGluR1a and Trx1 was not detected in the experiment.Conclusion mGluR1a induced production of ROS and cell death in HEK293 cells while Trx1 modulated cell death through scavenging intracellular ROS and regulating relevant signaling pathways.