The endoplasmic reticulum is a key site for protein production and quality control.More than one-third of proteins are synthesized and folded into the correct three-dimensional conformation in the endoplasmic reticulu...The endoplasmic reticulum is a key site for protein production and quality control.More than one-third of proteins are synthesized and folded into the correct three-dimensional conformation in the endoplasmic reticulum.However,during protein folding,unfolded and/or misfolded proteins are prone to occur,which may lead to endoplasmic reticulum stress.Organisms can monitor the quality of the proteins produced by endoplasmic reticulum quality control(ERQC)and endoplasmic reticulum-associated degradation(ERAD),which maintain endoplasmic reticulum protein homeostasis by degrading abnormally folded proteins.The underlying mechanisms of protein folding and ERAD in mammals have not yet been fully explored.Therefore,this paper reviews the process and function of protein folding and ERAD in mammalian cells,in order to help clinicians better understand the mechanism of ERAD and to provide a scientific reference for the treatment of diseases caused by abnormal ERAD.展开更多
The endoplasmic reticulum,a key cellular organelle,regulates a wide variety of cellular activities.Endoplasmic reticulum autophagy,one of the quality control systems of the endoplasmic reticulum,plays a pivotal role i...The endoplasmic reticulum,a key cellular organelle,regulates a wide variety of cellular activities.Endoplasmic reticulum autophagy,one of the quality control systems of the endoplasmic reticulum,plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover,remodeling,and proteostasis.In this review,we briefly describe the endoplasmic reticulum quality control system,and subsequently focus on the role of endoplasmic reticulum autophagy,emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular requirements.We also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative diseases.In summary,this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve disorders.This review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.展开更多
The hepatic endoplasmic reticulum(ER)-anchored cytochromes P450(P450s)are mixedfunction oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic...The hepatic endoplasmic reticulum(ER)-anchored cytochromes P450(P450s)are mixedfunction oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance.P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover.Such P450 proteolytic turnover occurs through a process known as ER-associated degradation(ERAD)that involves ubiquitindependent proteasomal degradation(UPD)and/or autophagic-lysosomal degradation(ALD).Herein,on the basis of available literature reports and our own recent findings of in vitro as well as in vivo experimental studies,we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance.We specifically(i)describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibodypathogenesis in drug-induced acute hypersensitivity reactions and liver injury,or viral hepatitis;(ⅱ)discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates;and(ⅲ)detail the pathophysiological consequences of disrupted P450 ERAD,contributing to non-alcoholic fatty liver disease(NAFLD)/non-alcoholic steatohepatitis(NASH)under certain synergistic cellular conditions.展开更多
The correct folding and assembly of newly synthesized secretory proteins are monitored by the protein quality control system of the endoplasmic reticulum （ER）. Through interactions with chaperones such as the bindin...The correct folding and assembly of newly synthesized secretory proteins are monitored by the protein quality control system of the endoplasmic reticulum （ER）. Through interactions with chaperones such as the binding protein （BiP） and other folding helpers, quality control favors productive folding and sorts for degradation defective proteins. A major route for quality control degradation identified in yeast, plants, and animals is constituted by retrotranslocation from the ER to the cytosol and subsequent disposal by the ubiquitin/proteasome system, but alternative routes involving the vacuole have been identified in yeast. In this study, we have studied the destiny of sGFP418, a fusion between a secretory form of GFP and a domain of the vacuolar protein phaseolin that is involved in the correct assembly of phaseolin and in BiP recognition of unassembled subunits. We show that sGFP418, despite lacking the phaseolin vacuolar sorting signal, is delivered to the vacuole and fragmented, in a process that is inhibited by the secretory traffic inhibitor brefeldin A. Moreover, a fusion between GFP and a domain of the maize storage protein γ-zein involved in zein polymerization also undergoes post-translational fragmentation similar to that of sGFP418. These results show that defective secretory proteins with permanently exposed sequences normally involved in oligomerization can be delivered to the vacuole by secretory traffic. This strongly suggests the existence of a plant vacuolar sorting mechanism devoted to the disposal of defective secretory proteins.展开更多
Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocy...Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.展开更多
Background The mechanism of hepatitis B virus(HBV)-induced carcinogenesis remains an area of interest.The accumulation of hepatitis B surface antigen in the endoplasmic reticulum(ER)of hepatocytes stimulates persisten...Background The mechanism of hepatitis B virus(HBV)-induced carcinogenesis remains an area of interest.The accumulation of hepatitis B surface antigen in the endoplasmic reticulum(ER)of hepatocytes stimulates persistent ER stress.Activity of the unfolded protein response(UPR)pathway of ER stress may play an important role in inflammatory cancer transformation.How the protective UPR pathway is hijacked by cells as a tool for malignant transformation in HBV-related hepatocellular carcinoma(HCC)is still unclear.Here,we aimed to define the key molecule hyaluronan-mediated motility receptor(HMMR)in this process and explore its role under ER stress in HCC development.Methods An HBV-transgenic mouse model was used to characterize the pathological changes during the tumor progression.Proteomics and transcriptomics analyses were performed to identify the potential key molecule,screen the E3 ligase,and define the activation pathway.Quantitative real-time PCR and Western blotting were conducted to detect the expression of genes in tissues and cell lines.Luciferase reporter assay,chromatin immunoprecipitation,coimmunoprecipitation,immunoprecipitation,and immunofluorescence were employed to investigate the molecular mechanisms of HMMR under ER stress.Immunohistochemistry was used to clarify the expression patterns of HMMR and related molecules in human tissues.Results We found sustained activation of ER stress in the HBV-transgenic mouse model of hepatitis-fibrosis-HCC.HMMR was transcribed by c/EBP homologous protein(CHOP)and degraded by tripartite motif containing 29(TRIM29)after ubiquitination under ER stress,which caused the inconsistent expression of mRNA and protein.Dynamic expression of TRIM29 in the HCC progression regulated the dynamic expression of HMMR.HMMR could alleviate ER stress by increasing autophagic lysosome activity.The negative correlation between HMMR and ER stress,positive correlation between HMMR and autophagy,and negative correlation between ER stress and autophagy were verified in human tissues.Conclusions This study identified the complicated role of HMMR in autophagy and ER stress,that HMMR controls the intensity of ER stress by regulating autophagy in HCC progression,which could be a novel explanation for HBV-related carcinogenesis.展开更多
散发性帕金森病(sporadic Parkinson's disease,sPD)的主要病理特征之一是中脑黑质致密部(substantia nigra pars compacta,SNpc)残存多巴胺能神经元内核周路易(小)体(Lewy body,LB)形成.LB发生的具体原因和确切过程有待进一步阐释...散发性帕金森病(sporadic Parkinson's disease,sPD)的主要病理特征之一是中脑黑质致密部(substantia nigra pars compacta,SNpc)残存多巴胺能神经元内核周路易(小)体(Lewy body,LB)形成.LB发生的具体原因和确切过程有待进一步阐释.来自遗传学、尸体解剖和实验科学的报道提示,蛋白酶体功能障碍及其所致的LB形成可能是按照聚集体形成途径(process of aggresomes)进行的.在聚集体形成途径过程中,异常蛋白质聚集基本上经历了非纤维化分子聚集过程(molecular crowding)以及后续的纤维化聚集过程(fibrilation of aggregation).其间,蛋白酶体功能障碍(dysfunction of proteasome)、内质网相关降解丧失(loss of endoplasmic reticulum associated degradation)、非纤维化聚集物(nonfibrilar aggregates)、聚集体(aggresomes)及至纤维化LB(fibrilar LB)等构成了sPD病变过程的主要事件.这提示在sPD病变过程中,蛋白酶体功能障碍及其所致的LB形成过程实质上是细胞信号的转导过程,其间涉及了众多的蛋白质分子.展开更多
内质网相关蛋白降解(ER-associated protein degradation,或ER-associateddegradation,ERAD)是真核细胞蛋白质质量控制的重要途径,它承担着对错误折叠蛋白的鉴别、分检和降解,清除无功能蛋白在细胞内的积累。ERAD过程包括错误折叠蛋白...内质网相关蛋白降解(ER-associated protein degradation,或ER-associateddegradation,ERAD)是真核细胞蛋白质质量控制的重要途径,它承担着对错误折叠蛋白的鉴别、分检和降解,清除无功能蛋白在细胞内的积累。ERAD过程包括错误折叠蛋白质的识别、蛋白质从ER向细胞基质逆向转运和蛋白质在细胞基质中的降解三个步骤。ERAD与人类的某些疾病密切相关,有些病毒能巧妙利用ERAD逃遁宿主免疫监控和攻击。展开更多
基金This work was supported by the National Natural Science Foundation of China(No.82071762)the Shanghai Key Lab of Human Performance(Shanghai University of Sport)(No.11DZ2261100)the 2021 Capacity Building of Shanghai Universities(No.21010503600),China。
文摘The endoplasmic reticulum is a key site for protein production and quality control.More than one-third of proteins are synthesized and folded into the correct three-dimensional conformation in the endoplasmic reticulum.However,during protein folding,unfolded and/or misfolded proteins are prone to occur,which may lead to endoplasmic reticulum stress.Organisms can monitor the quality of the proteins produced by endoplasmic reticulum quality control(ERQC)and endoplasmic reticulum-associated degradation(ERAD),which maintain endoplasmic reticulum protein homeostasis by degrading abnormally folded proteins.The underlying mechanisms of protein folding and ERAD in mammals have not yet been fully explored.Therefore,this paper reviews the process and function of protein folding and ERAD in mammalian cells,in order to help clinicians better understand the mechanism of ERAD and to provide a scientific reference for the treatment of diseases caused by abnormal ERAD.
基金supported by the National Natural Science Foundation of China,Nos.92049120 and 81870897STI2030-Major Projects,No.2021ZD0204001+6 种基金Guangdong Key Project for Development of New Tools for the Diagnosis and Treatment of Autism,No.2018B030335001the Natural Science Foundation of Jiangsu Province,No.BK20181436the National Major Scientific and Technological Special Project for Significant New Drug Development,No.2019ZX09301102the Discipline Construction Program of the Second Affiliated Hospital of Soochow University,No.XKTJ-TD202003Sino-German Cooperation Mobility Programme,No.M-0679the Science and Technology Project of Suzhou,No.SKY2022161Research Project of Neurological Diseases of the Second Affiliated Hospital of Soochow University Medical Center,No.ND2023A01(all to QHM)。
文摘The endoplasmic reticulum,a key cellular organelle,regulates a wide variety of cellular activities.Endoplasmic reticulum autophagy,one of the quality control systems of the endoplasmic reticulum,plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover,remodeling,and proteostasis.In this review,we briefly describe the endoplasmic reticulum quality control system,and subsequently focus on the role of endoplasmic reticulum autophagy,emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular requirements.We also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative diseases.In summary,this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve disorders.This review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.
基金supported by NIDDK Center Grant DK26743supported by NIH Grants GM44037 and DK26506(USA)to Maria Almira Correia.
文摘The hepatic endoplasmic reticulum(ER)-anchored cytochromes P450(P450s)are mixedfunction oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance.P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover.Such P450 proteolytic turnover occurs through a process known as ER-associated degradation(ERAD)that involves ubiquitindependent proteasomal degradation(UPD)and/or autophagic-lysosomal degradation(ALD).Herein,on the basis of available literature reports and our own recent findings of in vitro as well as in vivo experimental studies,we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance.We specifically(i)describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibodypathogenesis in drug-induced acute hypersensitivity reactions and liver injury,or viral hepatitis;(ⅱ)discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates;and(ⅲ)detail the pathophysiological consequences of disrupted P450 ERAD,contributing to non-alcoholic fatty liver disease(NAFLD)/non-alcoholic steatohepatitis(NASH)under certain synergistic cellular conditions.
文摘The correct folding and assembly of newly synthesized secretory proteins are monitored by the protein quality control system of the endoplasmic reticulum （ER）. Through interactions with chaperones such as the binding protein （BiP） and other folding helpers, quality control favors productive folding and sorts for degradation defective proteins. A major route for quality control degradation identified in yeast, plants, and animals is constituted by retrotranslocation from the ER to the cytosol and subsequent disposal by the ubiquitin/proteasome system, but alternative routes involving the vacuole have been identified in yeast. In this study, we have studied the destiny of sGFP418, a fusion between a secretory form of GFP and a domain of the vacuolar protein phaseolin that is involved in the correct assembly of phaseolin and in BiP recognition of unassembled subunits. We show that sGFP418, despite lacking the phaseolin vacuolar sorting signal, is delivered to the vacuole and fragmented, in a process that is inhibited by the secretory traffic inhibitor brefeldin A. Moreover, a fusion between GFP and a domain of the maize storage protein γ-zein involved in zein polymerization also undergoes post-translational fragmentation similar to that of sGFP418. These results show that defective secretory proteins with permanently exposed sequences normally involved in oligomerization can be delivered to the vacuole by secretory traffic. This strongly suggests the existence of a plant vacuolar sorting mechanism devoted to the disposal of defective secretory proteins.
基金supported by the National Natural Science Foundation of China,Nos.81901193(to HLZ)and 81901267(to YY)。
文摘Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.
基金National Natural Science Foundation of China,Grant/Award Number:82130084Shaanxi Provincial Key R&D Program,Grant/Award Number:2021SF-110。
文摘Background The mechanism of hepatitis B virus(HBV)-induced carcinogenesis remains an area of interest.The accumulation of hepatitis B surface antigen in the endoplasmic reticulum(ER)of hepatocytes stimulates persistent ER stress.Activity of the unfolded protein response(UPR)pathway of ER stress may play an important role in inflammatory cancer transformation.How the protective UPR pathway is hijacked by cells as a tool for malignant transformation in HBV-related hepatocellular carcinoma(HCC)is still unclear.Here,we aimed to define the key molecule hyaluronan-mediated motility receptor(HMMR)in this process and explore its role under ER stress in HCC development.Methods An HBV-transgenic mouse model was used to characterize the pathological changes during the tumor progression.Proteomics and transcriptomics analyses were performed to identify the potential key molecule,screen the E3 ligase,and define the activation pathway.Quantitative real-time PCR and Western blotting were conducted to detect the expression of genes in tissues and cell lines.Luciferase reporter assay,chromatin immunoprecipitation,coimmunoprecipitation,immunoprecipitation,and immunofluorescence were employed to investigate the molecular mechanisms of HMMR under ER stress.Immunohistochemistry was used to clarify the expression patterns of HMMR and related molecules in human tissues.Results We found sustained activation of ER stress in the HBV-transgenic mouse model of hepatitis-fibrosis-HCC.HMMR was transcribed by c/EBP homologous protein(CHOP)and degraded by tripartite motif containing 29(TRIM29)after ubiquitination under ER stress,which caused the inconsistent expression of mRNA and protein.Dynamic expression of TRIM29 in the HCC progression regulated the dynamic expression of HMMR.HMMR could alleviate ER stress by increasing autophagic lysosome activity.The negative correlation between HMMR and ER stress,positive correlation between HMMR and autophagy,and negative correlation between ER stress and autophagy were verified in human tissues.Conclusions This study identified the complicated role of HMMR in autophagy and ER stress,that HMMR controls the intensity of ER stress by regulating autophagy in HCC progression,which could be a novel explanation for HBV-related carcinogenesis.
文摘散发性帕金森病(sporadic Parkinson's disease,sPD)的主要病理特征之一是中脑黑质致密部(substantia nigra pars compacta,SNpc)残存多巴胺能神经元内核周路易(小)体(Lewy body,LB)形成.LB发生的具体原因和确切过程有待进一步阐释.来自遗传学、尸体解剖和实验科学的报道提示,蛋白酶体功能障碍及其所致的LB形成可能是按照聚集体形成途径(process of aggresomes)进行的.在聚集体形成途径过程中,异常蛋白质聚集基本上经历了非纤维化分子聚集过程(molecular crowding)以及后续的纤维化聚集过程(fibrilation of aggregation).其间,蛋白酶体功能障碍(dysfunction of proteasome)、内质网相关降解丧失(loss of endoplasmic reticulum associated degradation)、非纤维化聚集物(nonfibrilar aggregates)、聚集体(aggresomes)及至纤维化LB(fibrilar LB)等构成了sPD病变过程的主要事件.这提示在sPD病变过程中,蛋白酶体功能障碍及其所致的LB形成过程实质上是细胞信号的转导过程,其间涉及了众多的蛋白质分子.
文摘内质网相关蛋白降解(ER-associated protein degradation,或ER-associateddegradation,ERAD)是真核细胞蛋白质质量控制的重要途径,它承担着对错误折叠蛋白的鉴别、分检和降解,清除无功能蛋白在细胞内的积累。ERAD过程包括错误折叠蛋白质的识别、蛋白质从ER向细胞基质逆向转运和蛋白质在细胞基质中的降解三个步骤。ERAD与人类的某些疾病密切相关,有些病毒能巧妙利用ERAD逃遁宿主免疫监控和攻击。
