Objective Post-stroke cognitive impairment(PSCI)develops in approximately one-third of stroke survivors and is associated with ingravescence.Nonetheless,the biochemical mechanisms underlying PSCI remain unclear.The st...Objective Post-stroke cognitive impairment(PSCI)develops in approximately one-third of stroke survivors and is associated with ingravescence.Nonetheless,the biochemical mechanisms underlying PSCI remain unclear.The study aimed to establish an ischemic mouse model by means of transient unilateral middle cerebral artery occlusions(MCAOs)and to explore the biochemical mechanisms of p25/cyclin-dependent kinase 5(CDK5)-mediated tau hyperphosphorylation on the PSCI behavior.Methods Cognitive behavior was investigated,followed by the detection of tau hyperphosphorylation,mobilization,activation of kinases and/or inhibition of phosphatases in the lateral and contralateral cerebrum of mice following ischemia in MACO mice.Finally,we treated HEK293/tau cells with oxygen-glucose deprivation(OGD)and a CDK5 inhibitor(Roscovitine)or a GSK3βinhibitor(LiCl)to the roles of CDK5 and GSK3βin mediating ischemia-reperfusion-induced tau phosphorylation.Results Ischemia induced cognitive impairments within 2 months,as well as causing tau hyperphosphorylation and its localization to neuronal somata in both ipsilateral and contralateral cerebra.Furthermore,p25 that promotes CDK5 hyperactivation had significantly higher expression in the mice with MCAO than in the shamoperation(control)group,while the expression levels of protein phosphatase 2(PP2A)and the phosphorylation level at Tyr307 were comparable between the two groups.In addition,the CDK5 inhibitor rescued tau from hyperphosphorylation induced by OGD.Conclusion These findings demonstrate that upregulation of CDK5 mediates tau hyperphosphorylation and localization in both ipsilateral and contralateral cerebra,contributing to the pathogenesis of PSCI.展开更多
目的:探究在以SH-SY5Y细胞作为神经元代表,β淀粉样蛋白(Aβ25-35)诱导凋亡的阿尔茨海默症(Alzheimer′s Disease,AD)体外细胞模型中,西洋参水提物(water extracts of American Ginseng,WEAG)对神经元的保护作用。方法:流式细胞仪(FCM)...目的:探究在以SH-SY5Y细胞作为神经元代表,β淀粉样蛋白(Aβ25-35)诱导凋亡的阿尔茨海默症(Alzheimer′s Disease,AD)体外细胞模型中,西洋参水提物(water extracts of American Ginseng,WEAG)对神经元的保护作用。方法:流式细胞仪(FCM)检测确定Aβ25-35诱导SH-SY5Y细胞凋亡的最佳浓度和时间,以及WEAG抗凋亡的浓度,MTT法检测细胞存活率,Hoechst33258染色观察细胞形态的变化。结果:50μmol/L Aβ25-35诱导SH-SY5Y细胞72 h后,细胞变圆,聚集,Hoechst33258染色可见明显的颗粒状和固缩状荧光,FCM检测凋亡率达(37.30±0.69)%,与对照组(1.56±0.80)%比较,差异具有显著性意义(P<0.05)。而Aβ25-35和不同浓度的WEAG(0.5、1、5 mg/ml)同时孵育后,细胞形态明显改善,MTT值显著高于Aβ25-35处理组(P<0.01),凋亡率分别降低到(16.71±1.08)%、(10.52±2.11)%和(3.39±1.65)%,与Aβ25-35损伤组(37.30±0.69)%相比,差异具有统计学意义(p<0.05),并呈现出剂量依赖关系。结论:西洋参水提物对Aβ25-35诱导的SH-SY5Y细胞凋亡有显著的保护作用。展开更多
基金the National Natural Science Foundation of China(No.31800851)Natural Science Foundation of Hubei Province(No.2022CFB456)The Research Fund of Jianghan University(No.08210011).
文摘Objective Post-stroke cognitive impairment(PSCI)develops in approximately one-third of stroke survivors and is associated with ingravescence.Nonetheless,the biochemical mechanisms underlying PSCI remain unclear.The study aimed to establish an ischemic mouse model by means of transient unilateral middle cerebral artery occlusions(MCAOs)and to explore the biochemical mechanisms of p25/cyclin-dependent kinase 5(CDK5)-mediated tau hyperphosphorylation on the PSCI behavior.Methods Cognitive behavior was investigated,followed by the detection of tau hyperphosphorylation,mobilization,activation of kinases and/or inhibition of phosphatases in the lateral and contralateral cerebrum of mice following ischemia in MACO mice.Finally,we treated HEK293/tau cells with oxygen-glucose deprivation(OGD)and a CDK5 inhibitor(Roscovitine)or a GSK3βinhibitor(LiCl)to the roles of CDK5 and GSK3βin mediating ischemia-reperfusion-induced tau phosphorylation.Results Ischemia induced cognitive impairments within 2 months,as well as causing tau hyperphosphorylation and its localization to neuronal somata in both ipsilateral and contralateral cerebra.Furthermore,p25 that promotes CDK5 hyperactivation had significantly higher expression in the mice with MCAO than in the shamoperation(control)group,while the expression levels of protein phosphatase 2(PP2A)and the phosphorylation level at Tyr307 were comparable between the two groups.In addition,the CDK5 inhibitor rescued tau from hyperphosphorylation induced by OGD.Conclusion These findings demonstrate that upregulation of CDK5 mediates tau hyperphosphorylation and localization in both ipsilateral and contralateral cerebra,contributing to the pathogenesis of PSCI.
文摘目的:探究在以SH-SY5Y细胞作为神经元代表,β淀粉样蛋白(Aβ25-35)诱导凋亡的阿尔茨海默症(Alzheimer′s Disease,AD)体外细胞模型中,西洋参水提物(water extracts of American Ginseng,WEAG)对神经元的保护作用。方法:流式细胞仪(FCM)检测确定Aβ25-35诱导SH-SY5Y细胞凋亡的最佳浓度和时间,以及WEAG抗凋亡的浓度,MTT法检测细胞存活率,Hoechst33258染色观察细胞形态的变化。结果:50μmol/L Aβ25-35诱导SH-SY5Y细胞72 h后,细胞变圆,聚集,Hoechst33258染色可见明显的颗粒状和固缩状荧光,FCM检测凋亡率达(37.30±0.69)%,与对照组(1.56±0.80)%比较,差异具有显著性意义(P<0.05)。而Aβ25-35和不同浓度的WEAG(0.5、1、5 mg/ml)同时孵育后,细胞形态明显改善,MTT值显著高于Aβ25-35处理组(P<0.01),凋亡率分别降低到(16.71±1.08)%、(10.52±2.11)%和(3.39±1.65)%,与Aβ25-35损伤组(37.30±0.69)%相比,差异具有统计学意义(p<0.05),并呈现出剂量依赖关系。结论:西洋参水提物对Aβ25-35诱导的SH-SY5Y细胞凋亡有显著的保护作用。
