OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a ...OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a widely concerned drug target.Recent research has identified that Nrf2 is involved in the pathology of Alzheimer disease(AD),whereas the mechanism is unknown.The purpose of this study is to figure out the role of Nrf2 in the pathologic process of AD through Nrf2-Keap1-ARE pathway and the effects of Keap1-Nrf2 inhibitor in AD mice models.METHODS Amyloid β^(1-42)(Aβ^(1-42))was injected into the bilateral hippocampus to induce the cognitive dysfunction in eight-week old male mice.The mice were treated with Keap1-Nrf2 inhibitor NXPZ of three doses as well as donepezil as a positive control by intragastric administration one time a day for one week.Several behavior tests were used to analyze the mice learning and memory ability.Additionally,we detected Nrf2 and Aβ in the plasma in mice with ELISA kits,as well as some factors related to oxidative stress in the hippocampus and cortex.The expression levels of Nrf2,Keap1,Tau and p-Tau were measured in the murine brain tissue with Western blotting.SH-SY5 Y cells were studied as an in vitro model to further clarify the mechanism.RESULTS The treatment of NXPZ ameliorated learning and memory dysfunction in AD mice in a dose-dependent manner,and the high dose group recovered better than the positive drug group.The plasma Nrf2 level was increased in a dose-dependent manner in the treatment groups;however,the plasma Aβ was decreased.What′ s more,superoxide dismutase(SOD) and glutathione reductase(GSSH) in the hippocampus and cortex were increased in the treatment group,while the malondialdehyde(MDA) was decreased,meaning that NXPZ treatment promoted expression of the anti-oxidative factors and inhibited the expression of the oxidative factors in the down-stream.Western blotting analysis of hippocampus and cortex showed up-regulated Nrf2,decreased Keap1 and decreased p-Tau in NXPZ treatment mice.In ex vivo experiments,when SH-SY5 Y cells were treated with Aβ,Nrf2 in the cytoplasm was increased,as well as the expression Nrf2 in the nuclear was decreased.The treatment of NXPZ increased nuclear Nrf2,decreased cytoplasm Nrf2,and decreased the expression of p-Tau.CONCLUSION Nrf2 has an important role in neuron function.Nrf2 activation by selective Keap1-Nrf2 inhibitor NXPZ may contribute to improve cognitive function in AD mice.The mechanism may be related to increased generation and release of Nrf2 induced by more disaggregation with Keap1,leading to more expression of anti-oxidative molecules to protect the damage caused by Aβ.These results indicates that Nrf2 may be a novel therapeutic target of AD and Keap1-Nrf2 inhibitor may be a novel medication for protecting the loss of learning and memory ability.展开更多
目的通过建立氧糖剥夺-缺氧复氧(oxygen-glucose deprivation/reoxygenation,OGD/R)损伤模型模拟心肌缺血再灌注损伤,探讨海藻糖对OGD/R大鼠H9C2心肌细胞损伤的影响及其作用机制。方法H9C2细胞分为对照组、OGD/R组、海藻糖组(OGD/R+海藻...目的通过建立氧糖剥夺-缺氧复氧(oxygen-glucose deprivation/reoxygenation,OGD/R)损伤模型模拟心肌缺血再灌注损伤,探讨海藻糖对OGD/R大鼠H9C2心肌细胞损伤的影响及其作用机制。方法H9C2细胞分为对照组、OGD/R组、海藻糖组(OGD/R+海藻糖)、联合组(OGD/R+海藻糖+ML385)。四甲基偶氮唑盐法检测细胞增殖能力,并通过检测乳酸脱氢酶及Hoechst/丙啶碘化物染色检测细胞膜受损情况。Western blot检测核因子E2相关因子2(nuclear factor erythroid 2-related factor 2,Nrf2)及其下游相关蛋白表达;活性氧、线粒体膜电位检测氧化应激水平;Western blot检测凋亡相关蛋白表达。结果与对照组比较,OGD/R组细胞活力明显降低。与OGD/R组比较,不同浓度海藻糖干预能显著提升细胞活力,与海藻糖浓度呈正相关(P<0.01);与OGD/R组比较,海藻糖组线粒体膜电位(mitochondrial membrane potential,MMP)、谷胱甘肽(glutathione,GSH)、Nrf2、血红素加氧酶1和烟酰胺腺嘌呤二核苷酸磷酸醌氧化还原酶1、Bcl-2、半胱氨酸天冬氨酸蛋白酶3(cysteinyl aspartate specific proteinase-3,Caspase-3)表达明显增高,活性氧、丙二醛、应答元素结合蛋白1、Bax、Bax/Bcl-2、裂解型Caspase-3表达明显降低,差异有统计学意义(P<0.05,P<0.01)。与海藻糖组比较,联合组活性氧、丙二醛及肿瘤坏死因子α、白细胞介素(interleukin,IL)1βmRNA、IL-6 mRNA表达明显增高,MMP、GSH水平明显降低,差异有统计学意义(P<0.05,P<0.01);联合组Bax、Bax/Bcl-2、裂解型Caspase-3表达明显高于海藻糖组(1.77±0.08 vs 1.20±0.20,3.41±1.45 vs 0.99±0.15,4.10±1.05 vs 1.79±0.52,P<0.01),Bcl-2、Caspase-3表达明显低于海藻糖组(0.58±0.21 vs 1.23±0.25,0.87±0.25 vs 1.45±0.31,P<0.01)。结论海藻糖可以被视为一种Nrf2激活剂,通过激活Nrf2抑制氧化应激和凋亡,改善OGD/R诱导的心肌细胞损伤。展开更多
基金National Natural Science Foundation of China(81703520).
文摘OBJECTIVE Nuclear factor erythroid 2-related factor 2(Nrf2) is found to be ubiquitiously expressed in many tissues,and works as the key regulator against oxidative stress damage in cells and organs,which makes Nrf2 a widely concerned drug target.Recent research has identified that Nrf2 is involved in the pathology of Alzheimer disease(AD),whereas the mechanism is unknown.The purpose of this study is to figure out the role of Nrf2 in the pathologic process of AD through Nrf2-Keap1-ARE pathway and the effects of Keap1-Nrf2 inhibitor in AD mice models.METHODS Amyloid β^(1-42)(Aβ^(1-42))was injected into the bilateral hippocampus to induce the cognitive dysfunction in eight-week old male mice.The mice were treated with Keap1-Nrf2 inhibitor NXPZ of three doses as well as donepezil as a positive control by intragastric administration one time a day for one week.Several behavior tests were used to analyze the mice learning and memory ability.Additionally,we detected Nrf2 and Aβ in the plasma in mice with ELISA kits,as well as some factors related to oxidative stress in the hippocampus and cortex.The expression levels of Nrf2,Keap1,Tau and p-Tau were measured in the murine brain tissue with Western blotting.SH-SY5 Y cells were studied as an in vitro model to further clarify the mechanism.RESULTS The treatment of NXPZ ameliorated learning and memory dysfunction in AD mice in a dose-dependent manner,and the high dose group recovered better than the positive drug group.The plasma Nrf2 level was increased in a dose-dependent manner in the treatment groups;however,the plasma Aβ was decreased.What′ s more,superoxide dismutase(SOD) and glutathione reductase(GSSH) in the hippocampus and cortex were increased in the treatment group,while the malondialdehyde(MDA) was decreased,meaning that NXPZ treatment promoted expression of the anti-oxidative factors and inhibited the expression of the oxidative factors in the down-stream.Western blotting analysis of hippocampus and cortex showed up-regulated Nrf2,decreased Keap1 and decreased p-Tau in NXPZ treatment mice.In ex vivo experiments,when SH-SY5 Y cells were treated with Aβ,Nrf2 in the cytoplasm was increased,as well as the expression Nrf2 in the nuclear was decreased.The treatment of NXPZ increased nuclear Nrf2,decreased cytoplasm Nrf2,and decreased the expression of p-Tau.CONCLUSION Nrf2 has an important role in neuron function.Nrf2 activation by selective Keap1-Nrf2 inhibitor NXPZ may contribute to improve cognitive function in AD mice.The mechanism may be related to increased generation and release of Nrf2 induced by more disaggregation with Keap1,leading to more expression of anti-oxidative molecules to protect the damage caused by Aβ.These results indicates that Nrf2 may be a novel therapeutic target of AD and Keap1-Nrf2 inhibitor may be a novel medication for protecting the loss of learning and memory ability.
文摘目的通过建立氧糖剥夺-缺氧复氧(oxygen-glucose deprivation/reoxygenation,OGD/R)损伤模型模拟心肌缺血再灌注损伤,探讨海藻糖对OGD/R大鼠H9C2心肌细胞损伤的影响及其作用机制。方法H9C2细胞分为对照组、OGD/R组、海藻糖组(OGD/R+海藻糖)、联合组(OGD/R+海藻糖+ML385)。四甲基偶氮唑盐法检测细胞增殖能力,并通过检测乳酸脱氢酶及Hoechst/丙啶碘化物染色检测细胞膜受损情况。Western blot检测核因子E2相关因子2(nuclear factor erythroid 2-related factor 2,Nrf2)及其下游相关蛋白表达;活性氧、线粒体膜电位检测氧化应激水平;Western blot检测凋亡相关蛋白表达。结果与对照组比较,OGD/R组细胞活力明显降低。与OGD/R组比较,不同浓度海藻糖干预能显著提升细胞活力,与海藻糖浓度呈正相关(P<0.01);与OGD/R组比较,海藻糖组线粒体膜电位(mitochondrial membrane potential,MMP)、谷胱甘肽(glutathione,GSH)、Nrf2、血红素加氧酶1和烟酰胺腺嘌呤二核苷酸磷酸醌氧化还原酶1、Bcl-2、半胱氨酸天冬氨酸蛋白酶3(cysteinyl aspartate specific proteinase-3,Caspase-3)表达明显增高,活性氧、丙二醛、应答元素结合蛋白1、Bax、Bax/Bcl-2、裂解型Caspase-3表达明显降低,差异有统计学意义(P<0.05,P<0.01)。与海藻糖组比较,联合组活性氧、丙二醛及肿瘤坏死因子α、白细胞介素(interleukin,IL)1βmRNA、IL-6 mRNA表达明显增高,MMP、GSH水平明显降低,差异有统计学意义(P<0.05,P<0.01);联合组Bax、Bax/Bcl-2、裂解型Caspase-3表达明显高于海藻糖组(1.77±0.08 vs 1.20±0.20,3.41±1.45 vs 0.99±0.15,4.10±1.05 vs 1.79±0.52,P<0.01),Bcl-2、Caspase-3表达明显低于海藻糖组(0.58±0.21 vs 1.23±0.25,0.87±0.25 vs 1.45±0.31,P<0.01)。结论海藻糖可以被视为一种Nrf2激活剂,通过激活Nrf2抑制氧化应激和凋亡,改善OGD/R诱导的心肌细胞损伤。
