Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subseque...Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subsequent oxidative damage via suppression of autophagy and apoptosis. Cultured N2 a cells were pretreated with 10 μM methylprednisolone for 30 minutes, then exposed to 100 μM H2O2 for 24 hours. Inverted phase contrast microscope images, MTT assay, flow cytometry and western blot results showed that, compared to cells exposed to 100 μM H2O2 alone, cells pretreated with methylprednisolone had a significantly lower percentage of apoptotic cells, maintained a healthy morphology, and showed downregulation of autophagic protein light chain 3B and Beclin-1 protein expression. These findings indicate that methylprednisolone exerted neuroprotective effects against oxidative damage by suppressing autophagy and apoptosis.展开更多
Lithium promotes autophagy and has a neuroprotective effect on spinal cord injury（SCI）; however, the underlying mechanisms remain unclear. Therefore, in this study, we investigated the effects of lithium and the aut...Lithium promotes autophagy and has a neuroprotective effect on spinal cord injury（SCI）; however, the underlying mechanisms remain unclear. Therefore, in this study, we investigated the effects of lithium and the autophagy inhibitor 3-methyladenine（3-MA） in a rat model of SCI. The rats were randomly assigned to the SCI, lithium, 3-MA and sham groups. In the 3-MA group, rats were intraperitoneally injected with 3-MA（3 mg/kg） 2 hours before SCI. In the lithium and 3-MA groups, rats were intraperitoneally injected with lithium（LiCl; 30 mg/kg） 6 hours after SCI and thereafter once daily until sacrifice. At 2, 3 and 4 weeks after SCI, neurological function and diffusion tensor imaging indicators were remarkably improved in the lithium group compared with the SCI and 3-MA groups. The Basso, Beattie and Bresnahan locomotor rating scale score and fractional anisotropy values were increased, and the apparent diffusion coefficient value was decreased. Immunohistochemical staining showed that immunoreactivities for Beclin-1 and light-chain 3 B peaked 1 day after SCI in the lithium and SCI groups. Immunoreactivities for Beclin-1 and light-chain 3 B were weaker in the 3-MA group than in the SCI group, indicating that 3-MA inhibits lithium-induced autophagy. Furthermore, NeuN＋ neurons were more numerous in the lithium group than in the SCI and 3-MA groups, with the fewest in the latter. Our findings show that lithium reduces neuronal damage after acute SCI and promotes neurological recovery by inducing autophagy. The neuroprotective mechanism of action may not be entirely dependent on the enhancement of autophagy, and furthermore, 3-MA might not completely inhibit all autophagy pathways.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
Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun1...Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 （FUNDC1） was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with micro-tubule-associated protein light chain 3 beta （LC3B） through its LC3 interaction region （LIR）. Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDCI LIR peptide phosphorylated at Ser17 （pS17）, demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS17. Alternatively, phosphorylated Tyr18 （PY18） and Ser13 （PS13） in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry （ITC） assays. Therefore, our structural and biochemical results reveal a working model for thespecific recognition of FUNDCI by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.展开更多
目的：评价α硫辛酸对人皮肤成纤维细胞自噬水平的影响。方法人皮肤成纤维细胞与终浓度分别为0、0.05、0.10、0.15、0.20和0.50 mmol/L 的α硫辛酸孵育4、12和24 h 后，采用噻唑蓝法检测细胞增殖活性，单丹酰戊二胺（MDC）染色法检测细...目的：评价α硫辛酸对人皮肤成纤维细胞自噬水平的影响。方法人皮肤成纤维细胞与终浓度分别为0、0.05、0.10、0.15、0.20和0.50 mmol/L 的α硫辛酸孵育4、12和24 h 后，采用噻唑蓝法检测细胞增殖活性，单丹酰戊二胺（MDC）染色法检测细胞自噬水平，Western 印迹法检测微管相关蛋白1轻链3-B（LC3-B）表达。结果孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间人皮肤成纤维细胞增殖活性（A490值）差异均无统计学意义（F 值分别为2.85、1.34，均 P 〉0.05）；孵育24 h 时，各组间差异有统计学意义（F =10.41，P 〈0.01）。MDC 法检测显示，孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间自噬体阳性细胞百分率差异均无统计学意义（F 值分别为0.11、0.10，均 P 〉0.05）；孵育24 h 时，各组间差异有统计学意义（F =8.03，P 〈0.05）。Western 印迹法检测显示，孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间细胞 LC3-Ⅰ向 LC3-Ⅱ转化（LC3-Ⅱ/LC3-Ⅰ）水平差异均无统计学意义（F 值分别为3.38、2.13，均 P 〉0.05），但孵育24 h 时各组间差异有统计学意义（F =37.49，P 〈0.01）。结论α硫辛酸可能抑制人皮肤成纤维细胞基础自噬。展开更多
基金supported by the National Natural Science Foundation of China,No.81171799,81471854the Science and Technology Research Project of Education Department of Liaoning Province of China,No.L2013333+1 种基金the"College Students’Science and Technology Innovation Project"of Liaoning Medical University Principal Fund-Aohong Boze Fund of China,No.2014D08the Liaoning Medical University Principal Fund-Aohong Boze Graduate Student Science Research Innovation Fund,No.AH2014017
文摘Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subsequent oxidative damage via suppression of autophagy and apoptosis. Cultured N2 a cells were pretreated with 10 μM methylprednisolone for 30 minutes, then exposed to 100 μM H2O2 for 24 hours. Inverted phase contrast microscope images, MTT assay, flow cytometry and western blot results showed that, compared to cells exposed to 100 μM H2O2 alone, cells pretreated with methylprednisolone had a significantly lower percentage of apoptotic cells, maintained a healthy morphology, and showed downregulation of autophagic protein light chain 3B and Beclin-1 protein expression. These findings indicate that methylprednisolone exerted neuroprotective effects against oxidative damage by suppressing autophagy and apoptosis.
基金supported by the Beijing Excellent Talent Training Funding in China,No.2017000021469G215(to DZ)the Youth Science Foundation of Beijing Tiantan Hospital of China,No.2016-YQN-14(to DZ)+1 种基金the Natural Science Foundation of Capital Medical University of China,No.PYZ2017082(to DZ)the Xi’an Science and Technology Project in China,No.2016048SF/YX04(3)(to XHL)
文摘Lithium promotes autophagy and has a neuroprotective effect on spinal cord injury（SCI）; however, the underlying mechanisms remain unclear. Therefore, in this study, we investigated the effects of lithium and the autophagy inhibitor 3-methyladenine（3-MA） in a rat model of SCI. The rats were randomly assigned to the SCI, lithium, 3-MA and sham groups. In the 3-MA group, rats were intraperitoneally injected with 3-MA（3 mg/kg） 2 hours before SCI. In the lithium and 3-MA groups, rats were intraperitoneally injected with lithium（LiCl; 30 mg/kg） 6 hours after SCI and thereafter once daily until sacrifice. At 2, 3 and 4 weeks after SCI, neurological function and diffusion tensor imaging indicators were remarkably improved in the lithium group compared with the SCI and 3-MA groups. The Basso, Beattie and Bresnahan locomotor rating scale score and fractional anisotropy values were increased, and the apparent diffusion coefficient value was decreased. Immunohistochemical staining showed that immunoreactivities for Beclin-1 and light-chain 3 B peaked 1 day after SCI in the lithium and SCI groups. Immunoreactivities for Beclin-1 and light-chain 3 B were weaker in the 3-MA group than in the SCI group, indicating that 3-MA inhibits lithium-induced autophagy. Furthermore, NeuN＋ neurons were more numerous in the lithium group than in the SCI and 3-MA groups, with the fewest in the latter. Our findings show that lithium reduces neuronal damage after acute SCI and promotes neurological recovery by inducing autophagy. The neuroprotective mechanism of action may not be entirely dependent on the enhancement of autophagy, and furthermore, 3-MA might not completely inhibit all autophagy pathways.
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.
基金This work was supported by National Natural Science Founda- tion （Grant No. 31400629） the Strategic Priority Research Program of the Chinese Academy of Science （No. XDB08010101）+1 种基金 Ministry Of Science And Technology of China （No. 2016YFA0500700） China Postdoctoral Science Foundation （No. 2015M582009 and 2016T90579） and National Natural Science Foundation （Grant No. 31330018）.
文摘Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 （FUNDC1） was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with micro-tubule-associated protein light chain 3 beta （LC3B） through its LC3 interaction region （LIR）. Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDCI LIR peptide phosphorylated at Ser17 （pS17）, demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS17. Alternatively, phosphorylated Tyr18 （PY18） and Ser13 （PS13） in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry （ITC） assays. Therefore, our structural and biochemical results reveal a working model for thespecific recognition of FUNDCI by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.
文摘目的：评价α硫辛酸对人皮肤成纤维细胞自噬水平的影响。方法人皮肤成纤维细胞与终浓度分别为0、0.05、0.10、0.15、0.20和0.50 mmol/L 的α硫辛酸孵育4、12和24 h 后，采用噻唑蓝法检测细胞增殖活性，单丹酰戊二胺（MDC）染色法检测细胞自噬水平，Western 印迹法检测微管相关蛋白1轻链3-B（LC3-B）表达。结果孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间人皮肤成纤维细胞增殖活性（A490值）差异均无统计学意义（F 值分别为2.85、1.34，均 P 〉0.05）；孵育24 h 时，各组间差异有统计学意义（F =10.41，P 〈0.01）。MDC 法检测显示，孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间自噬体阳性细胞百分率差异均无统计学意义（F 值分别为0.11、0.10，均 P 〉0.05）；孵育24 h 时，各组间差异有统计学意义（F =8.03，P 〈0.05）。Western 印迹法检测显示，孵育4 h 和12 h 时，0、0.05、0.10、0.15、0.20和0.50 mmol/L α硫辛酸组间细胞 LC3-Ⅰ向 LC3-Ⅱ转化（LC3-Ⅱ/LC3-Ⅰ）水平差异均无统计学意义（F 值分别为3.38、2.13，均 P 〉0.05），但孵育24 h 时各组间差异有统计学意义（F =37.49，P 〈0.01）。结论α硫辛酸可能抑制人皮肤成纤维细胞基础自噬。
