Family with sequence similarity 134 member B-mediated reticulophagy ameliorates hepatocyte apoptosis induced by dithiothreitol  

作　　者：Yi-Xin Guo Bing Han Ting Yang Yu-Si Chen Yi Yang Jia-Yao Li Qin Yang Ru-Jia Xie 

机构地区：[1]Department of Pathophysiology,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases,Guizhou Medical University,Guiyang 550025,Guizhou Province,China [2]Department of Pathophysiology,College of Basic Medical Sciences,Guizhou Medical University,Guiyang 550025,Guizhou Province,China

出　　处：《World Journal of Gastroenterology》2022年第23期2569-2581,共13页世界胃肠病学杂志（英文版）

基　　金：Supported by National Natural Science Foundation of China,No.81560105;Science and Technology Foundation of Guizhou Province,No.Qiankehe Jichu-ZK[2021]365,and No.Qiankehe Pingtai Rencai[2019]5801;National Natural Science Foundation Cultivation Project of Guizhou Medical University,No.20NSP016。

摘　　要：BACKGROUND Endoplasmic reticulum(ER)stress-related hepatocyte apoptosis is responsible for multiple hepatic diseases.Previous studies have revealed that endoplasmic reticulophagy(ER-phagy)promotes the selective clearance of damaged ER fragments during ER stress,playing a crucial role in maintaining ER homeostasis and inhibiting apoptosis.Family with sequence similarity 134 member B(FAM134B)is a receptor involved in ER-phagy that can form a complex with calnexin(CNX)and microtubule-associated protein 1 light chain 3(LC3).The complex can mediate the selective isolation of ER fragments to attenuate hepatocyte apoptosis.However,the precise regulatory mechanisms remain unclear.AIM To elucidate the effect of FAM134B-mediated ER-phagy on ER stress-induced apoptosis in buffalo rat liver 3A(BRL-3A)rat hepatocytes and the potential regulatory mechanisms.METHODS ER stress-related hepatocyte apoptosis was induced using dithiothreitol(DTT).Proteins related to ER stress and autophagy were measured with western blotting.Protein complex interactions with FAM134B were isolated by co-immunoprecipitation.ER-phagy was evaluated in immunofluorescence experiments.Cell cycle distribution and apoptosis were measured by flow cytometry.Mitochondrial Ca^(2+) levels were evaluated by the co-localization of intracellular Ca^(2+)-tracker and Mitotracker.The small interfering RNA against FAM134B was used to knockdown FAM134B in BRL-3A cells.RESULTS ER stress-related and autophagy-related proteins in BRL-3A cells were elevated by both short and long-term DTT treatment.Furthermore,co-immunoprecipitation confirmed an interaction between FAM134B,CNX,FAM134B,and LC3 in BRL-3A cells.Immunofluorescence assays revealed that autolysosomes significantly decreased following short-term DTT treatment,but increased after long-term treatment.Mitochondrial Ca2+levels and apoptotic rates were dramatically elevated,and more cells were arrested in the G1 stage after short-term DTT treatment;however,these decreased 48 h later.Moreover,FAM134B downregulation accel

关 键 词：HEPATOCYTES Reticulophagy Family with sequence similarity 134 member B Apoptosis Endoplasmic reticulum stress Endoplasmic reticulum homeostasis 

分 类 号：R735.7[医药卫生—肿瘤]