SIRT7通过抑制内质网应激蛋白GRP78减轻脂多糖或D-氨基半乳糖/脂多糖诱导的肝细胞凋亡  

SIRT7 protecting hepatocytes from LPS or D-GalN/LPS-induced apoptosis by attenuating endoplasmic reticulum stress via inactivation of GRP78

作　　者：阮昕[1] 张颖婷 韩可琪 林龙帅 陈晨[1] 岳铭 王楚翘 孙英刚[3] 赵庆华[2] 贺明[1] RUAN Xin;ZHANG Ying-ting;HAN Ke-qi;LIN Long-shuai;CHEN Chen;YUE Ming;WANG Chu-qiao;SUN Ying-gang;ZHAO Qing-hua;HE Ming(Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education,Shanghai 200025,China;Department of Orthopedics,Shanghai General Hospital,Shanghai Jiao Tong University,Shanghai 201620,China;Department of Cardiology,Xinhua Hospital,Shanghai Jiao Tong University School of Medicine,Shanghai 200092,China)

机构地区：[1]上海交通大学基础医学院病理生理学系,细胞分化与凋亡教育部重点实验室,上海200025 [2]上海交通大学附属第一人民医院骨科,上海201620 [3]上海交通大学医学院附属新华医院心血管内科,上海200092

出　　处：《上海交通大学学报（医学版）》2019年第8期812-819,共8页Journal of Shanghai Jiao tong University:Medical Science

基　　金：国家自然科学基金(81470841);上海市浦江人才计划(16PJ1405400,16PJ0004679);上海市自然科学基金(19ZR1428400);上海交通大学医工(理)交叉研究基金(YG2017MS02)~~

摘　　要：目的·探究SIRT7(sirtuin 7)对脂多糖(lipopolysaccharide,LPS)或D-氨基半乳糖(D-galactosamine,D-GalN)/LPS诱导的急性肝损伤的作用及机制。方法·将13周龄的C57BL/6J小鼠随机分为生理盐水组(n=5)、LPS组(n=7)和D-GalN/LPS组(n=8),分别腹腔注射生理盐水、LPS和D-GalN/LPS。24 h后收集生理盐水组和LPS组的小鼠血清和肝脏,D-GalN/LPS组于注射后8 h收集血清和肝脏。利用苏木精-伊红(H-E)染色比较3组小鼠肝脏病理学改变,同时观察血清学生化指标的变化;利用TUNEL染色和F4/80染色明确小鼠肝脏内细胞凋亡和炎症细胞浸润程度;利用realtime-PCR检测各组小鼠肝组织中SIRT7、白介素-1β(interleukin 1β,IL-1β)、IL-6、肿瘤坏死因子α(tumor necrosis factorα,TNF-α)等的mRNA水平;利用Western blotting检测各组小鼠肝组织中SIRT7、激活型胱天蛋白酶3(cleaved-caspase3)和伴侣葡萄糖调节蛋白(the 78 kDa glucose regulated protein,GRP78)等的蛋白水平。体外实验中,在正常小鼠肝细胞AML-12细胞中过表达SIRT7,并给予LPS刺激,利用Western blotting明确SIRT7对LPS引起的内质网应激信号通路分子的调控。结果·注射LPS或D-GalN/LPS后,小鼠肝脏出现明显的炎症细胞浸润、充血及肝细胞凋亡,血清中谷丙转氨酶(glutamic-pyruvic transaminase,GPT)和谷草转氨酶(glutamic-oxalacetic transaminase,GOT)水平明显升高,肝组织中SIRT7的mRNA和蛋白水平均明显降低,内质网应激蛋白GRP78表达明显上调。在AML-12细胞系中,SIRT7过表达可明显抑制LPS引起的GRP78蛋白上调。结论·SIRT7通过抑制内质网应激中的GRP78减轻LPS或D-GalN/LPS诱导的肝细胞凋亡。Objective·To investigate the effects of SIRT7 on acute liver injury induced by lipopolysaccharide(LPS)or D-galactosamine(D-GalN)/LPS and its mechanisms.Methods·Thirteen-week-old C57BL/6J mice were randomly divided into normal saline group(n=5),LPS group(n=7),and D-GalN/LPS group(n=8),which were respectively intraperitoneally injected with normal saline,LPS or D-GalN/LPS.The serum and livers of normal saline group and LPS group mice were collected 24 hours after the injection,and the samples of D-GalN/LPS group were collected 8 hours after the injection.Liver pathological changes were compared by using H-E staining,and serological indicators of the mice from three groups were also compared.Liver apoptosis and inflammatory cells infiltration were determined by TUNEL staining and F4/80 staining.Meanwhile,the mRNA levels of SIRT7 and inflammatory factors,including interleukin-1β(IL-1β),IL-6,and tumor necrosis factorα(TNF-α)in livers were detected by realtime-PCR.Western blotting was used to detect the protein levels of SIRT7,cleaved-caspase3 and the 78 kDa glucose regulated protein(GRP78)in mouse liver tissues.AML-12 cell line overexpressing SIRT7 was stimulated with LPS,and Western blotting was used to study the roles of SIRT7 in the endoplasmic reticulum(ER)stress induced by LPS in vitro.Results·LPS or D-GalN/LPS induced inflammatory cells infiltration,hyperemia and hepatocytes apoptosis in livers.Meanwhile,serum glutamic-pyruvic transaminase(GPT)and glutamic-oxalacetic transaminase(GOT)in the mice treated by LPS or D-GalN/LPS were significantly increased.Moreover,both liver SIRT7 mRNA and protein levels were down-regulated,while GRP78 protein in ER stress pathway was up-regulated.In AML-12 cells,SIRT7 overexpression inhibited LPS-induced up-regulation of GRP78.Conclusion·SIRT7 protects against LPS or D-GalN/LPS-induced hepatocytes apoptosis by attenuating ER stress via inactivating GRP78.

关 键 词：去乙酰化酶(sirtuin) 脓毒症 SIRT7 急性肝损伤 内质网应激 细胞凋亡 

分 类 号：R575.1[医药卫生—消化系统]