BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an imp...BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.展开更多
目的:探讨酸敏感离子通道1a(ASIC1a)、弱内向整流钾通道相关的酸敏感钾通道1和3(TASK-1和TASK-3)在大鼠癫痫持续状态(SE)中的表达及其在癫痫持续状态中的作用.方法:成年雄性SD大鼠随机分为对照组(control)和SE组,应用氯化锂-匹罗卡品诱...目的:探讨酸敏感离子通道1a(ASIC1a)、弱内向整流钾通道相关的酸敏感钾通道1和3(TASK-1和TASK-3)在大鼠癫痫持续状态(SE)中的表达及其在癫痫持续状态中的作用.方法:成年雄性SD大鼠随机分为对照组(control)和SE组,应用氯化锂-匹罗卡品诱导SE模型,采用real time RT-PCR和Western Blot技术分别检测海马组织ASIC1a、TASK-1和TASK-3在SE后0、1、2和3 h mRNA、蛋白表达水平,应用膜片钳技术观察SE后ASIC1a、TASK-1和TASK-3对海马CA1区锥体神经元兴奋性的影响.结果:在mRNA水平,与control组相比,SE组ASIC1a在2和3h、TASK-1在1h、TASK-3在3h时间点表达显著减少.在蛋白水平,与control组相比,SE组ASIC1a、TASK-1和TASK-3在3h时间点表达均显著降低.与SE control组相比,给予ASIC1a抑制剂后动作电位(AP)的频率明显降低,给予TASK-1和TASK-3抑制剂后,AP的频率均显著增加.结论:SE后大鼠海马区ASIC1a、TASK-1和TASK-3表达下调,且ASIC1a、TASK-1和TASK-3改变了海马CA1区锥体神经元的兴奋性,参与了SE的发生过程.展开更多
基金Supported by the Natural Science Foundation of Hebei Province,No.H2021206187 and No.H2021206452.
文摘BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.
文摘目的:探讨酸敏感离子通道1a(ASIC1a)、弱内向整流钾通道相关的酸敏感钾通道1和3(TASK-1和TASK-3)在大鼠癫痫持续状态(SE)中的表达及其在癫痫持续状态中的作用.方法:成年雄性SD大鼠随机分为对照组(control)和SE组,应用氯化锂-匹罗卡品诱导SE模型,采用real time RT-PCR和Western Blot技术分别检测海马组织ASIC1a、TASK-1和TASK-3在SE后0、1、2和3 h mRNA、蛋白表达水平,应用膜片钳技术观察SE后ASIC1a、TASK-1和TASK-3对海马CA1区锥体神经元兴奋性的影响.结果:在mRNA水平,与control组相比,SE组ASIC1a在2和3h、TASK-1在1h、TASK-3在3h时间点表达显著减少.在蛋白水平,与control组相比,SE组ASIC1a、TASK-1和TASK-3在3h时间点表达均显著降低.与SE control组相比,给予ASIC1a抑制剂后动作电位(AP)的频率明显降低,给予TASK-1和TASK-3抑制剂后,AP的频率均显著增加.结论:SE后大鼠海马区ASIC1a、TASK-1和TASK-3表达下调,且ASIC1a、TASK-1和TASK-3改变了海马CA1区锥体神经元的兴奋性,参与了SE的发生过程.
