OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF r...OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.展开更多
The mammalian target of rapamycin （mTOR） signaling pathway is evolutionarily conserved, mTOR can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, e...The mammalian target of rapamycin （mTOR） signaling pathway is evolutionarily conserved, mTOR can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, energy and stress conditions, and has a crucial role in the vertebrate growth control. This review analyzed the main components and regulated factors of TOR signaling pathway, explained functions and mechanisms of roTOR during the individual growth, the development and its dynamic role, revealed its additional functions beyond the cell growth control, and finally reviewed the tissue specificity and time specificity of mTOR signaling pathway, and its regulation on sexual differentiation, tissue differentiation and organogenesis in the individual development.展开更多
目的探讨淫羊藿总黄酮(total flavonoids of epimedium,TFE)对自然衰老大鼠皮层自噬的调节作用及分子机制。方法HE染色和Nissl染色观察大鼠皮层神经元形态学变化,Western blot检测自噬相关蛋白LC3、p62、Beclin1以及AMPK-mTOR信号途径...目的探讨淫羊藿总黄酮(total flavonoids of epimedium,TFE)对自然衰老大鼠皮层自噬的调节作用及分子机制。方法HE染色和Nissl染色观察大鼠皮层神经元形态学变化,Western blot检测自噬相关蛋白LC3、p62、Beclin1以及AMPK-mTOR信号途径关键蛋白在皮层组织中的表达水平。结果HE染色和Nissl染色结果显示,与青年对照组大鼠相比,衰老模型组大鼠皮层神经元丢失,排列散乱,且变性神经元数量增多,给予淫羊藿总黄酮干预后,神经元数量增多,变性神经元数量减少;Western blot结果表明,与青年大鼠相比,自然衰老大鼠下调p-AMPK/AMPK、LC3Ⅱ/Ⅰ、Beclin1蛋白表达水平,上调p-mTOR/mTOR、p62蛋白表达水平,给予淫羊藿总黄酮干预后可上调p-AMPK/AMPK、LC3Ⅱ/Ⅰ、Beclin1蛋白表达水平,下调p-mTOR/mTOR、p62蛋白表达水平。结论TFE可上调自然衰老大鼠皮层自噬,其机制可能与调节AMPK-mTOR信号途径有关。展开更多
目的:探讨在低氧高二氧化碳(hypoxia and hypercapnia,HH)条件下,基于AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路的细胞自噬的变化及其对大鼠肺动脉平...目的:探讨在低氧高二氧化碳(hypoxia and hypercapnia,HH)条件下,基于AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路的细胞自噬的变化及其对大鼠肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)增殖和凋亡的影响。方法:以大鼠PASMCs为研究对象,饥饿24 h后随机分为5组:正常对照(normal control,N)组、模型组(HH组)、溶剂二甲基亚砜(dimethyl sulfoxide,DMSO)组(D组)、AMPK激动剂阿卡地新(acadesine;5-aminoimidazole-4-carboxamide riboside,AICAR)组(AI组)和AMPK抑制剂dorsomorphin(compound C,CC)组(CC组)。N组置于常氧环境(21%O_(2)、5%CO_(2)和74%N2)下培养24 h,其余4组预先加入相对应的干预药物置于HH条件(5%O_(2)、6%CO_(2)和89%N2)下培养24 h进行造模。造模结束后用CCK-8法测各组细胞活力;5-乙炔基-2’-脱氧尿苷(5-ethynyl-2’-deoxyuridine,EdU)法检测细胞增殖;TUNEL检测细胞凋亡;qPCR法检测微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)、p62及caspase-3的mRNA表达;免疫印迹法检测AMPK、p-AMPK、mTOR、p-mTOR、LC3、p62、caspase-3和增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)蛋白水平;透射电镜观察自噬小体。结果:与N组相比,HH组PASMCs活力增强,EdU阳性率增加,凋亡率降低;LC3的mRNA表达上调,p62和caspase-3的mRNA表达下调;p-AMPK/AMPK比值、LC3-II/LC3-I比值和PCNA蛋白表达上调,p-mTOR/mTOR比值及p62和caspase-3蛋白表达下调;电镜下观察到细胞内有少量自噬小体。与HH组相比,AI组PASMCs活力进一步增强,EdU阳性率增加,凋亡率降低;LC3的mRNA表达上调,p62和caspase-3的mRNA表达下调;p-AMPK/AMPK比值、LC3-II/LC3-I比值和PCNA蛋白表达上调,p-mTOR/mTOR比值及p62和caspase-3蛋白表达下调;电镜形态表现为细胞自噬小体数量增加。而CC组较HH组PASMCs活力和EdU阳性率显著降低,凋亡率显著升高;LC3的mRNA表达下调,p62和caspase-3的mRNA表达上调;p-AMPK/AMPK比值、LC3-II/LC3-I比值和PCNA蛋白表达下调,p-mTOR/mTOR比值及p62和caspase-3蛋白表达上调;电镜下观察到细胞自噬小体数量减少。结论:在HH环境下,基于AMPK/mTOR信号通路的细胞自噬启动可能是大鼠PASMCs增殖增加、凋亡减少的机制之一。展开更多
基金National Natural Science Foundation of China(8166070081260679)Ningxia College FirstClass Discipline Construction Project(Chinese Medicine)Funded Project(NXYLXK2017A06)
文摘OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.
文摘The mammalian target of rapamycin （mTOR） signaling pathway is evolutionarily conserved, mTOR can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, energy and stress conditions, and has a crucial role in the vertebrate growth control. This review analyzed the main components and regulated factors of TOR signaling pathway, explained functions and mechanisms of roTOR during the individual growth, the development and its dynamic role, revealed its additional functions beyond the cell growth control, and finally reviewed the tissue specificity and time specificity of mTOR signaling pathway, and its regulation on sexual differentiation, tissue differentiation and organogenesis in the individual development.
