GO通过氧化损伤激活秀丽线虫未折叠蛋白反应

GO Induced Unfolded Protein Response in C. elegans through Oxidative Stress

以秀丽线虫为受试生物,探讨氧化石墨烯(GO)对秀丽线虫未折叠蛋白应答的激活及其与氧化应激的关系。将L4幼虫暴露于GO中24h,通过检测活性氧(ROS)水平、乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)等指标评估GO对秀丽线虫所致氧化损伤;以hsp-4和hsp-6分别作为秀丽线虫内质网和线粒体未折叠蛋白反应(UPR)的报告基因评价GO对秀丽线虫UPR应答的激活;同时以谷胱甘肽(GSH)作为抗氧化剂探讨GO所致UPR应答与氧化应激的关系。研究结果显示,GO暴露后秀丽线虫体内ROS、LDH和MDA水平升高,抗氧化酶活性上升;内质网和线粒体UPR反应增强,GSH预处理可以降低内质网和线粒体UPR应答。研究表明,GO短期暴露可以诱导秀丽线虫机体氧化应激进而激活UPR应答,抗氧化保护可以降低UPR应答反应。

The aim of this work was to explore the underlying mechanisms of unfolded protein response (UPR) induced by graphene oxide (GO) and the association of UPR with oxidative stress in nematode C.elegans.L4 nema- todes were exposed to GO for 24 hours,then reactive oxygen species (ROS),lactate dehydrogenase (LDH),malondialdehyde (MDA),superoxide dismutase (SOD),catalase (CAT) and glutathione peroxidase (GSH-Px) were evaluated. The hsp -4 and hsp -6 were used as markers for endoplasmic reticulum (UPRER ) and mitochondria (UPRmt ) unfolded protein response respectively.The antioxidant glutathione (GSH) was used to detect the association of UPR with oxidative stress in response to the toxicity of GO.The levels of ROS,LDH and MDA were significantly increased in GO exposed C.elegans at the concentration from 1 mg·L^-1 to 100 mg·L^-1.The expression of hsp -4 and hsp -6 were significantly upregulated after GO exposure,which suggested that the UPRmt and UPRER were activated by GO.The antioxidant GSH could inhibit the activation of the UPRmt and UPRER response.These data demonstrated that GO exposure can induce oxidative stress in the organism of C.elegans and then activate the UPRmt and UPRER.The antioxidant GSH could suppress the UPRmt and UPRER through reducing the oxidative stress.