细胞自噬(autophagy)是从酵母到哺乳动物都高度保守的、降解胞内物质的过程,受到能量和营养等信号的严格调控。已有研究表明,哺乳动物中高脂饮食可诱导肝脏内自噬的发生,某些自噬相关基因(autophagy related genes,Atg)敲除后阻碍肝脏...细胞自噬(autophagy)是从酵母到哺乳动物都高度保守的、降解胞内物质的过程,受到能量和营养等信号的严格调控。已有研究表明,哺乳动物中高脂饮食可诱导肝脏内自噬的发生,某些自噬相关基因(autophagy related genes,Atg)敲除后阻碍肝脏细胞的脂代谢,并导致脂滴堆积,形成脂肪肝。昆虫中的现有研究也暗示细胞自噬与昆虫脂肪体的代谢密切相关。目前为止,细胞自噬调控脂代谢的研究还有许多不明之处。除已报道的ATG蛋白外是否其他ATG蛋白也参与脂代谢尚无报道;已知的参与脂代谢的ATG蛋白分子作用模式不清楚;溶酶体中哪些酶参与了自噬介导的脂代谢也未被证实。ATG蛋白差异参与真菌和高等动物的脂滴形成与脂肪降解,但具体机制不详,昆虫的进化地位介于高等动物和真菌之间,昆虫中开展自噬介导脂代谢的研究对于解析高等动物的疾病诸如肥胖症、高血脂症,及以昆虫脂肪体代谢发育为调控靶标的工作具有重要意义。为此,本文对主要在哺乳动物中获得的自噬介导脂代谢的研究进展进行综述,并对脂代谢的一些研究方法和检测技术进行了总结,以期为昆虫乃至其他生物的相关研究提供借鉴与参考。展开更多
Autophagy is a regulated process for the degradation of cellular components that has been well conserved in eukaryotic cells. The discovery of autophagy-regulating proteins in yeast has been important in understanding...Autophagy is a regulated process for the degradation of cellular components that has been well conserved in eukaryotic cells. The discovery of autophagy-regulating proteins in yeast has been important in understanding this process. Although many parallels exist between fungi and mammals in the regulation and execution of autophagy, there are some important differences. The preautophagosomal structure found in yeast has not been identified in mammals, and it seems that there may be multiple origins for autophagosomes, including endoplasmic reticulum, plasma membrane and mitochondrial outer membrane. The maturation of the phagophore is largely dependent on 5'-AMP activated protein kinase and other factors that lead to the dephosphorylation of mammalian target of rapamycin. Once the process is initiated, the mammalian phagophore elongates and matures into an autophagosome by processes that are similar to those in yeast. Cargo selection is dependent on the ubiquitin conjugation of protein aggregates and organelles and recognition of these conjugates by autophagosomal receptors. Lysosomal degradation of cargo produces metabolites that can be recycled during stress. Autophagy is an impor-tant cellular safeguard during starvation in all eukaryotes; however, it may have more complicated, tissue specific roles in mammals. With certain exceptions, autophagy seems to be cytoprotective, and defects in the process have been associated with human disease.展开更多
Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient sta...Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient starvation.展开更多
Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Ch...Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.展开更多
Macroautophagy is a conserved degradative process mediated through formation of a unique double- membrane structure, the autophagosome. The discovery of autophagy-related （Atg） genes required for autophagosome forma...Macroautophagy is a conserved degradative process mediated through formation of a unique double- membrane structure, the autophagosome. The discovery of autophagy-related （Atg） genes required for autophagosome formation has led to the characterization of approximately 20 genes mediating this process. Recent structural studies of the Atg proteins have provided the molecular basis for their function. Here we summarize the recent progress in elucidating the structural basis for autophagosome formation.展开更多
文摘细胞自噬(autophagy)是从酵母到哺乳动物都高度保守的、降解胞内物质的过程,受到能量和营养等信号的严格调控。已有研究表明,哺乳动物中高脂饮食可诱导肝脏内自噬的发生,某些自噬相关基因(autophagy related genes,Atg)敲除后阻碍肝脏细胞的脂代谢,并导致脂滴堆积,形成脂肪肝。昆虫中的现有研究也暗示细胞自噬与昆虫脂肪体的代谢密切相关。目前为止,细胞自噬调控脂代谢的研究还有许多不明之处。除已报道的ATG蛋白外是否其他ATG蛋白也参与脂代谢尚无报道;已知的参与脂代谢的ATG蛋白分子作用模式不清楚;溶酶体中哪些酶参与了自噬介导的脂代谢也未被证实。ATG蛋白差异参与真菌和高等动物的脂滴形成与脂肪降解,但具体机制不详,昆虫的进化地位介于高等动物和真菌之间,昆虫中开展自噬介导脂代谢的研究对于解析高等动物的疾病诸如肥胖症、高血脂症,及以昆虫脂肪体代谢发育为调控靶标的工作具有重要意义。为此,本文对主要在哺乳动物中获得的自噬介导脂代谢的研究进展进行综述,并对脂代谢的一些研究方法和检测技术进行了总结,以期为昆虫乃至其他生物的相关研究提供借鉴与参考。
文摘Autophagy is a regulated process for the degradation of cellular components that has been well conserved in eukaryotic cells. The discovery of autophagy-regulating proteins in yeast has been important in understanding this process. Although many parallels exist between fungi and mammals in the regulation and execution of autophagy, there are some important differences. The preautophagosomal structure found in yeast has not been identified in mammals, and it seems that there may be multiple origins for autophagosomes, including endoplasmic reticulum, plasma membrane and mitochondrial outer membrane. The maturation of the phagophore is largely dependent on 5'-AMP activated protein kinase and other factors that lead to the dephosphorylation of mammalian target of rapamycin. Once the process is initiated, the mammalian phagophore elongates and matures into an autophagosome by processes that are similar to those in yeast. Cargo selection is dependent on the ubiquitin conjugation of protein aggregates and organelles and recognition of these conjugates by autophagosomal receptors. Lysosomal degradation of cargo produces metabolites that can be recycled during stress. Autophagy is an impor-tant cellular safeguard during starvation in all eukaryotes; however, it may have more complicated, tissue specific roles in mammals. With certain exceptions, autophagy seems to be cytoprotective, and defects in the process have been associated with human disease.
基金supported by the National Basic Research Program of China (973 Program)(No.2016YFA0100400)the National Natural Science Foundation of China(No.81773009)
文摘Autophagy is an evolutionarily conserved lysosome-mediated catabolic process（Klionsky,2007）.Autophagy is believed to be essential for cell survival,especially when cells were exposed to stresses,such as nutrient starvation.
基金funding support from the National Natural Science Foundation of China(No.81704065)Hunan Provincial Natural Science Foundation(No.2019JJ40225)+1 种基金the Scientific Research Project of Education Department of Hunan Province(No.19B415,No.19C1393 and No.20C1392)Hunan Provincial Scientific Research Project of Chinese Medicine(No.2020015)。
文摘Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.
文摘Macroautophagy is a conserved degradative process mediated through formation of a unique double- membrane structure, the autophagosome. The discovery of autophagy-related （Atg） genes required for autophagosome formation has led to the characterization of approximately 20 genes mediating this process. Recent structural studies of the Atg proteins have provided the molecular basis for their function. Here we summarize the recent progress in elucidating the structural basis for autophagosome formation.
