Non-alcoholic fatty liver disease(NAFLD)is a disorder of lipid metabolism.The lipotoxic intermediates of lipid metabolism cause mitochondrial dysfunction and endoplasmic reticulum stress.Organelle-specific autophagy i...Non-alcoholic fatty liver disease(NAFLD)is a disorder of lipid metabolism.The lipotoxic intermediates of lipid metabolism cause mitochondrial dysfunction and endoplasmic reticulum stress.Organelle-specific autophagy is responsible for the removal of dysfunctional organelles to maintain intracellular homeostasis.Lipophagy contributes to lipid turnover by degrading lipid droplets.The level of autophagy changes during the course of NAFLD,and the activation of hepatocyte autophagy might represent a method of treating NAFLD.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essent...BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essential role in HCC tumorigenesis.Suberoylanilide hydroxamic acid(SAHA),the most common histone deacetylase inhibitor agent,triggers many forms of cell death in HCC.However,the underlying mechanism of action remains unclear.Family with sequence similarity 134 member B(FAM134B)-induced reticulophagy,a selective autophagic pathway,participates in the decision of cell fate and exhibits anticancer activity.This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.AIM To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.METHODS The viability,apoptosis,cell cycle,migration,and invasion of SAHA-treated Huh7 and MHCC97L cells were measured.Proteins related to the reticulophagy pathway,mitochondria-endoplasmic reticulum(ER)contact sites,intrinsic mitochondrial apoptosis,and histone acetylation were quantified using western blotting.ER and lysosome colocalization,and mitochondrial Ca^(2+)levels were characterized via confocal microscopy.The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization.Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.RESULTS After SAHA treatment,the proliferation of Huh7 and MHCC97L cells was significantly inhibited,and the migration and invasion abilities were greatly blocked in vitro.This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner.Following treatment with SAHA,ER-phagy was activated,thereby triggering autophagy-mediated cell death of HCC cells in vitro.Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B pr展开更多
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 cleara...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展开更多
目的探讨内质网自噬在大鼠胃窦Cajal间质细胞(ICCs)内质网应激(ERS)过程中的作用,为改善胃动力障碍提供新靶标。方法采用酶解法分离大鼠胃窦ICCs并行免疫荧光鉴定,使用衣霉素(TM)诱导ICCs构建ERS模型,三甲基腺嘌呤(3-MA)阻断自噬,雷帕霉...目的探讨内质网自噬在大鼠胃窦Cajal间质细胞(ICCs)内质网应激(ERS)过程中的作用,为改善胃动力障碍提供新靶标。方法采用酶解法分离大鼠胃窦ICCs并行免疫荧光鉴定,使用衣霉素(TM)诱导ICCs构建ERS模型,三甲基腺嘌呤(3-MA)阻断自噬,雷帕霉素(Rapa)促进自噬。随机将细胞分为4组并分别给予不同的处理,ICCs组正常培养,ERS组给予2μg/m L TM处理ICCs,3-MA组给予2μg/m L TM和4μmol/m L 3-MA联合作用,Rapa组给予2μg/m L TM和2μmol/m L Rapa联合作用,每组作用时间均为6 h;通过实时荧光定量PCR法检测ERS相关因子GRP78、自噬相关因子LC3B的mRNA表达;CCK-8法检测各组细胞活性。结果成功分离并鉴定ICCs。与ICCs组比较,ERS组、3-MA组和Rapa组的GRP78和LC3B表达均升高(P均<0.05),细胞活性降低(P均<0.05)。与ERS组比较,3-MA组GRP78表达升高(P<0.05),LC3B表达、ICCs细胞活性降低(P均<0.05);Rapa组GRP78表达降低(P<0.05),LC3B表达、ICCs细胞活性升高(P均<0.05)。结论 ICCs的ERS过程伴发内质网自噬,内质网自噬可减轻ICCs的ERS损伤作用。展开更多
Reticulophagy is a type of selective autophagy in which protein aggregate-containing and/or damaged endoplasmic reticulum(ER)fragments are engulfed for lysosomal degradation, which is important for ER homeostasis. Sev...Reticulophagy is a type of selective autophagy in which protein aggregate-containing and/or damaged endoplasmic reticulum(ER)fragments are engulfed for lysosomal degradation, which is important for ER homeostasis. Several chemical drugs and mutant proteins that promote protein aggregate formation within the ER lumen can efficiently induce reticulophagy in mammalian cells.However, the exact mechanism and cellular localization of reticulophagy remain unclear. In this report, we took advantage of the self-oligomerization property of p62/SQSTM1, an adaptor for selective autophagy, and developed a novel reticulophagy system based on an ER-targeted p62 mutant to investigate the process of reticulophagy in living cells. LC3 conversion analysis via western blot suggested that p62 mutant aggregate-induced ER stress triggered a cellular autophagic response. Confocal imaging showed that in cells with moderate aggregation conditions, the aggregates of ER-targeted p62 mutants were efficiently sequestered by autophagosomes, which was characterized by colocalization with the autophagosome precursor marker ATG16L1, the omegasome marker DFCP1, and the late autophagosomal marker LC3/GATE-16. Moreover, time-lapse imaging data demonstrated that the LC3-or DFCP1-positive protein aggregates are tightly associated with the reticular structures of the ER, thereby suggesting that reticulophagy occurs at the ER and that omegasomes may be involved in this process.展开更多
基金supported by grants from the Beijing Advanced Innovation Center for Big Data-Based Precision Medicine(No.PXM2021_014226_000026)the Capital Funds for Health Improvement and Research(No.2021-1G-2181).
文摘Non-alcoholic fatty liver disease(NAFLD)is a disorder of lipid metabolism.The lipotoxic intermediates of lipid metabolism cause mitochondrial dysfunction and endoplasmic reticulum stress.Organelle-specific autophagy is responsible for the removal of dysfunctional organelles to maintain intracellular homeostasis.Lipophagy contributes to lipid turnover by degrading lipid droplets.The level of autophagy changes during the course of NAFLD,and the activation of hepatocyte autophagy might represent a method of treating NAFLD.
基金the National Natural Science Foundation of China,No.82260127Guizhou Provincial Science and Technology Projects,No.Qiankehe Jichu-ZK[2021]365 and Qiankehe Jichu-ZK[2021]364+2 种基金National Natural Science Foundation Cultivation Project of Guizhou Medical University,No.20NSP016Guizhou Provincial Natural Science Foundation,No.[2021]4029 and[2022]4017Science and Technology Foundation of Guizhou Provincial Health Commission,No.gzwjkj2019-1-102.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a common clinical condition with a poor prognosis and few effective treatment options.Potent anticancer agents for treating HCC must be identified.Epigenetics plays an essential role in HCC tumorigenesis.Suberoylanilide hydroxamic acid(SAHA),the most common histone deacetylase inhibitor agent,triggers many forms of cell death in HCC.However,the underlying mechanism of action remains unclear.Family with sequence similarity 134 member B(FAM134B)-induced reticulophagy,a selective autophagic pathway,participates in the decision of cell fate and exhibits anticancer activity.This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.AIM To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.METHODS The viability,apoptosis,cell cycle,migration,and invasion of SAHA-treated Huh7 and MHCC97L cells were measured.Proteins related to the reticulophagy pathway,mitochondria-endoplasmic reticulum(ER)contact sites,intrinsic mitochondrial apoptosis,and histone acetylation were quantified using western blotting.ER and lysosome colocalization,and mitochondrial Ca^(2+)levels were characterized via confocal microscopy.The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization.Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.RESULTS After SAHA treatment,the proliferation of Huh7 and MHCC97L cells was significantly inhibited,and the migration and invasion abilities were greatly blocked in vitro.This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner.Following treatment with SAHA,ER-phagy was activated,thereby triggering autophagy-mediated cell death of HCC cells in vitro.Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B pr
基金Supported by National Natural Science Foundation of China,No.81560105Science and Technology Foundation of Guizhou Province,No.Qiankehe Jichu-ZK[2021]365,and No.Qiankehe Pingtai Rencai[2019]5801National Natural Science Foundation Cultivation Project of Guizhou Medical University,No.20NSP016。
文摘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
文摘目的探讨内质网自噬在大鼠胃窦Cajal间质细胞(ICCs)内质网应激(ERS)过程中的作用,为改善胃动力障碍提供新靶标。方法采用酶解法分离大鼠胃窦ICCs并行免疫荧光鉴定,使用衣霉素(TM)诱导ICCs构建ERS模型,三甲基腺嘌呤(3-MA)阻断自噬,雷帕霉素(Rapa)促进自噬。随机将细胞分为4组并分别给予不同的处理,ICCs组正常培养,ERS组给予2μg/m L TM处理ICCs,3-MA组给予2μg/m L TM和4μmol/m L 3-MA联合作用,Rapa组给予2μg/m L TM和2μmol/m L Rapa联合作用,每组作用时间均为6 h;通过实时荧光定量PCR法检测ERS相关因子GRP78、自噬相关因子LC3B的mRNA表达;CCK-8法检测各组细胞活性。结果成功分离并鉴定ICCs。与ICCs组比较,ERS组、3-MA组和Rapa组的GRP78和LC3B表达均升高(P均<0.05),细胞活性降低(P均<0.05)。与ERS组比较,3-MA组GRP78表达升高(P<0.05),LC3B表达、ICCs细胞活性降低(P均<0.05);Rapa组GRP78表达降低(P<0.05),LC3B表达、ICCs细胞活性升高(P均<0.05)。结论 ICCs的ERS过程伴发内质网自噬,内质网自噬可减轻ICCs的ERS损伤作用。
基金supported by the Major Research Plan of the National Natural Science Foundation of China (91442201)the National Science Fund for Distinguished Young Scholars (81625012)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (61421064)
文摘Reticulophagy is a type of selective autophagy in which protein aggregate-containing and/or damaged endoplasmic reticulum(ER)fragments are engulfed for lysosomal degradation, which is important for ER homeostasis. Several chemical drugs and mutant proteins that promote protein aggregate formation within the ER lumen can efficiently induce reticulophagy in mammalian cells.However, the exact mechanism and cellular localization of reticulophagy remain unclear. In this report, we took advantage of the self-oligomerization property of p62/SQSTM1, an adaptor for selective autophagy, and developed a novel reticulophagy system based on an ER-targeted p62 mutant to investigate the process of reticulophagy in living cells. LC3 conversion analysis via western blot suggested that p62 mutant aggregate-induced ER stress triggered a cellular autophagic response. Confocal imaging showed that in cells with moderate aggregation conditions, the aggregates of ER-targeted p62 mutants were efficiently sequestered by autophagosomes, which was characterized by colocalization with the autophagosome precursor marker ATG16L1, the omegasome marker DFCP1, and the late autophagosomal marker LC3/GATE-16. Moreover, time-lapse imaging data demonstrated that the LC3-or DFCP1-positive protein aggregates are tightly associated with the reticular structures of the ER, thereby suggesting that reticulophagy occurs at the ER and that omegasomes may be involved in this process.
