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:探讨人参皂苷Rh1对糖尿病(DM)小鼠肾损伤的保护作用,并阐明其作用机制。方法:应用高脂高糖饲养佐以腹腔注射链脲佐菌素(STZ)法制备糖尿病肾脏疾病(DKD)模型。将48只C57/BL6成模小鼠随机分为模型组、核因子红细胞2相关因子2(Nrf2)...目的:探讨人参皂苷Rh1对糖尿病(DM)小鼠肾损伤的保护作用,并阐明其作用机制。方法:应用高脂高糖饲养佐以腹腔注射链脲佐菌素(STZ)法制备糖尿病肾脏疾病(DKD)模型。将48只C57/BL6成模小鼠随机分为模型组、核因子红细胞2相关因子2(Nrf2)抑制剂ML385组(ML385组)(30 mg·kg^(-1)ML385)、人参皂苷Rh1组(G-Rh1组)(30 mg·kg^(-1)人参皂苷Rh1)和G-Rh1+ML385组(30 mg·kg^(-1)人参皂苷Rh1+30 mg·kg^(-1)ML385),每组12只,另外12只C57/BL6小鼠作为对照组。作用8周后,全自动分析仪检测各组小鼠血清中空腹血糖(FBG)、尿素氮(BUN)和血肌酐(Scr)水平及尿液中24 h尿蛋白(24 h UP)水平,并计算肾脏指数。试剂盒检测各组小鼠肾组织中超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)活性及丙二醛(MDA)水平,Western blotting法检测各组小鼠肾组织中Nrf2和血红素加氧酶1(HO-1)蛋白表达水平。结果:与对照组比较,模型组、ML385组和G-Rh1+ML385组小鼠血清中FBG水平和肾脏指数均明显升高(P<0.01),G-Rh1组小鼠血清中FBG水平明显升高(P<0.01);与模型组比较,ML385组小鼠肾脏指数明显升高(P<0.05),G-Rh1组小鼠FBG水平和肾脏指数均明显降低(P<0.05或P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠FBG水平和肾脏指数均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显升高(P<0.01);与模型组比较,ML385组小鼠血清中BUN水平及尿液中24 h UP水平均明显升高(P<0.05),G-Rh1组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显降低(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠肾组织中SOD活性均明显降低(P<0.01),MDA水平和LDH活性均明显升高(P<0.01);与模型组比较,ML385组小鼠肾组织中SOD活性明显降低(P<0.05),MDA水平明显升高(P<0.05),G-Rh1组小鼠肾组织中SOD活性明显升高(P<0.01),MDA水平和LDH活性均明显降低(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠肾组织中SOD活性明显降低(P<0.01),MDA水平和LDH活性均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.05或P<0.01);与模型组比较,ML385组和G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.05),G-Rh1组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显升高(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.01)。结论:人参皂苷Rh1可降低氧化应激,改善肾功能,对DM小鼠肾脏损伤具有保护作用,其作用机制可能与激活Nrf2/HO-1信号通路有关。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:探讨人参皂苷Rh1对糖尿病(DM)小鼠肾损伤的保护作用,并阐明其作用机制。方法:应用高脂高糖饲养佐以腹腔注射链脲佐菌素(STZ)法制备糖尿病肾脏疾病(DKD)模型。将48只C57/BL6成模小鼠随机分为模型组、核因子红细胞2相关因子2(Nrf2)抑制剂ML385组(ML385组)(30 mg·kg^(-1)ML385)、人参皂苷Rh1组(G-Rh1组)(30 mg·kg^(-1)人参皂苷Rh1)和G-Rh1+ML385组(30 mg·kg^(-1)人参皂苷Rh1+30 mg·kg^(-1)ML385),每组12只,另外12只C57/BL6小鼠作为对照组。作用8周后,全自动分析仪检测各组小鼠血清中空腹血糖(FBG)、尿素氮(BUN)和血肌酐(Scr)水平及尿液中24 h尿蛋白(24 h UP)水平,并计算肾脏指数。试剂盒检测各组小鼠肾组织中超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)活性及丙二醛(MDA)水平,Western blotting法检测各组小鼠肾组织中Nrf2和血红素加氧酶1(HO-1)蛋白表达水平。结果:与对照组比较,模型组、ML385组和G-Rh1+ML385组小鼠血清中FBG水平和肾脏指数均明显升高(P<0.01),G-Rh1组小鼠血清中FBG水平明显升高(P<0.01);与模型组比较,ML385组小鼠肾脏指数明显升高(P<0.05),G-Rh1组小鼠FBG水平和肾脏指数均明显降低(P<0.05或P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠FBG水平和肾脏指数均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显升高(P<0.01);与模型组比较,ML385组小鼠血清中BUN水平及尿液中24 h UP水平均明显升高(P<0.05),G-Rh1组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显降低(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠血清中BUN和Scr水平及尿液中24 h UP水平均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠肾组织中SOD活性均明显降低(P<0.01),MDA水平和LDH活性均明显升高(P<0.01);与模型组比较,ML385组小鼠肾组织中SOD活性明显降低(P<0.05),MDA水平明显升高(P<0.05),G-Rh1组小鼠肾组织中SOD活性明显升高(P<0.01),MDA水平和LDH活性均明显降低(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠肾组织中SOD活性明显降低(P<0.01),MDA水平和LDH活性均明显升高(P<0.01)。与对照组比较,模型组、ML385组、G-Rh1组和G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.05或P<0.01);与模型组比较,ML385组和G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.05),G-Rh1组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显升高(P<0.01);与G-Rh1组比较,G-Rh1+ML385组小鼠肾组织中Nrf2和HO-1蛋白表达水平均明显降低(P<0.01)。结论:人参皂苷Rh1可降低氧化应激,改善肾功能,对DM小鼠肾脏损伤具有保护作用,其作用机制可能与激活Nrf2/HO-1信号通路有关。
