Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic a...Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.展开更多
研究白藜芦醇(resveratrol,Res)对内质网应激途径细胞凋亡和糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK-3β)/Tau蛋白磷酸化作用的影响。体外原代培养神经元细胞,采用衣霉素(tunicamycin,TM)建立内质网应激模型,Western blo...研究白藜芦醇(resveratrol,Res)对内质网应激途径细胞凋亡和糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK-3β)/Tau蛋白磷酸化作用的影响。体外原代培养神经元细胞,采用衣霉素(tunicamycin,TM)建立内质网应激模型,Western blot法检测内质网分子伴侣蛋白葡萄糖调节蛋白78(glucose-regulated protein 78,GRP78)、未折叠蛋白反应相关的肌醇需要酶1α(inositol-requiring enzyme 1α,IRE1α)的Ser724磷酸化、剪接的X盒结合蛋白1(spliced form of X-box binding protein 1s,XBP1s)表达、GSK-3β的Ser9和Tau蛋白的Ser396磷酸化水平。生物化学方法分析细胞质中半胱天冬酶-12(Caspase-12)和半胱天冬酶-3(Caspase-3)活性、细胞凋亡水平。结果显示,TM能够诱导内质网应激作用,导致神经元细胞GSK-3β的活化和Tau蛋白磷酸化水平升高(P<0.01)、神经元细胞经内质网途径凋亡(P<0.05)。与内质网应激抑制剂4-苯基丁酸结果相似,Res组显著降低了GRP78的表达(P<0.01)、降低了IRE1α-XBP1通路的活性(P<0.01)。Res可以减缓TM诱导的内质网途径细胞凋亡级联反应中Caspase-12和Caspase-3的活性(P<0.01)。Res抑制了TM诱导的GSK-3β的Ser9位点磷酸化水平和Tau蛋白Ser396位点的磷酸化水平(P<0.01)。结果表明,Res能够降低TM诱导的IRE1α-XBP1途径内质网应激作用、GSK-3β的活性及Tau蛋白发生磷酸化水平,减弱神经元细胞经内质网途径凋亡的级联反应作用。展开更多
文摘Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.
文摘研究白藜芦醇(resveratrol,Res)对内质网应激途径细胞凋亡和糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK-3β)/Tau蛋白磷酸化作用的影响。体外原代培养神经元细胞,采用衣霉素(tunicamycin,TM)建立内质网应激模型,Western blot法检测内质网分子伴侣蛋白葡萄糖调节蛋白78(glucose-regulated protein 78,GRP78)、未折叠蛋白反应相关的肌醇需要酶1α(inositol-requiring enzyme 1α,IRE1α)的Ser724磷酸化、剪接的X盒结合蛋白1(spliced form of X-box binding protein 1s,XBP1s)表达、GSK-3β的Ser9和Tau蛋白的Ser396磷酸化水平。生物化学方法分析细胞质中半胱天冬酶-12(Caspase-12)和半胱天冬酶-3(Caspase-3)活性、细胞凋亡水平。结果显示,TM能够诱导内质网应激作用,导致神经元细胞GSK-3β的活化和Tau蛋白磷酸化水平升高(P<0.01)、神经元细胞经内质网途径凋亡(P<0.05)。与内质网应激抑制剂4-苯基丁酸结果相似,Res组显著降低了GRP78的表达(P<0.01)、降低了IRE1α-XBP1通路的活性(P<0.01)。Res可以减缓TM诱导的内质网途径细胞凋亡级联反应中Caspase-12和Caspase-3的活性(P<0.01)。Res抑制了TM诱导的GSK-3β的Ser9位点磷酸化水平和Tau蛋白Ser396位点的磷酸化水平(P<0.01)。结果表明,Res能够降低TM诱导的IRE1α-XBP1途径内质网应激作用、GSK-3β的活性及Tau蛋白发生磷酸化水平,减弱神经元细胞经内质网途径凋亡的级联反应作用。
