OBJECTIVE Chronic cerebral hy⁃poperfusion can lead to progressive demyelin⁃ation and ischemic vascular dementia,yet there are no effective treatments.METHODS Magnetic resonance imaging was employed in patients with wh...OBJECTIVE Chronic cerebral hy⁃poperfusion can lead to progressive demyelin⁃ation and ischemic vascular dementia,yet there are no effective treatments.METHODS Magnetic resonance imaging was employed in patients with white matter damage,and optogenetics and skin stroking were exerted to activate glutamater⁃gic neurons in the somatosensory cortex in a clas⁃sical mouse model of ischemia vascular dementia.RESULTS White matter damage was correlated with disrupted cortical structure from MRI results.In a mouse model,activating glutamatergic neu⁃rons in the somatosensory cortex promotes prolif⁃eration of OPCs and remyelination to rescue cog⁃nitive impairment after chronic cerebral hypoper⁃fusion.Such therapeutic action was limited to stimulation with moderate intensity at the upper layers of the cortex,but was achieved over a wide time window after ischemia.Mechanistically,enhanced glutamatergic neuron-OPC functional synaptic connections are required for protection from activation of cortical glutamatergic neurons.Finally,skin stroking activation of the somatosen⁃sory cortex,an easier approach for clinical trans⁃lation,promoted OPC proliferation and remyelin⁃ation as well as cognitive recovery after cerebral hypoperfusion.CONCLUSION Activation of gluta⁃matergic neurons in the somatosensory cortex may serve as novel approaches for treating isch⁃emic vascular dementia through precise modula⁃tion of glutamatergic neuron-OPC circuits.展开更多
目的研究血管性痴呆(vascular dementia,VaD)小鼠模型海马神经元的死亡机制,探讨海马神经元程序性坏死与VaD小鼠学习记忆受损之间的关系。方法慢性脑低灌注血管性痴呆小鼠模型采用双侧血管阻断法(bilateral occlusion of the common car...目的研究血管性痴呆(vascular dementia,VaD)小鼠模型海马神经元的死亡机制,探讨海马神经元程序性坏死与VaD小鼠学习记忆受损之间的关系。方法慢性脑低灌注血管性痴呆小鼠模型采用双侧血管阻断法(bilateral occlusion of the common carotid arteries,2VO)构建。用Morris水迷宫检测小鼠模型学习记忆能力。用实时荧光定量PCR(qPCR)法检测动物模型海马区神经元RIPK1、RIPK3和MLKL mRNA的表达。免疫印迹法检测RIPK1、RIPK3、pRIPK3和MLKL蛋白的表达,并与小鼠模型学习记忆能力进行相关性分析。免疫荧光双标记法检测RIPK1、RIPK3和MLKL的共定位情况。结果qPCR检测发现,与假手术组相比,VaD组小鼠模型海马区神经元RIPK1、RIPK3和MLKL的mRNA表达显著增高。免疫印迹结果显示VaD组小鼠模型海马区神经元RIPK1、pRIPK3、和MLKL的蛋白表达水平明显增高。免疫荧光双标记显示在小鼠模型海马区,RIPK1、RIPK3与MLKL共表达定位显著增强。进一步研究发现,程序性坏死标志物RIPK1、RIPK3和MLKL的表达与小鼠模型目标象限停留时间及穿越平台次数呈负相关关系。结论在VaD小鼠模型中,海马神经元的丢失及其学习记忆功能障碍的发生发展,可能是通过激活RIPK1/RIPK3/MLKL信号通路,进而引起海马神经元程序性坏死所致。展开更多
文摘OBJECTIVE Chronic cerebral hy⁃poperfusion can lead to progressive demyelin⁃ation and ischemic vascular dementia,yet there are no effective treatments.METHODS Magnetic resonance imaging was employed in patients with white matter damage,and optogenetics and skin stroking were exerted to activate glutamater⁃gic neurons in the somatosensory cortex in a clas⁃sical mouse model of ischemia vascular dementia.RESULTS White matter damage was correlated with disrupted cortical structure from MRI results.In a mouse model,activating glutamatergic neu⁃rons in the somatosensory cortex promotes prolif⁃eration of OPCs and remyelination to rescue cog⁃nitive impairment after chronic cerebral hypoper⁃fusion.Such therapeutic action was limited to stimulation with moderate intensity at the upper layers of the cortex,but was achieved over a wide time window after ischemia.Mechanistically,enhanced glutamatergic neuron-OPC functional synaptic connections are required for protection from activation of cortical glutamatergic neurons.Finally,skin stroking activation of the somatosen⁃sory cortex,an easier approach for clinical trans⁃lation,promoted OPC proliferation and remyelin⁃ation as well as cognitive recovery after cerebral hypoperfusion.CONCLUSION Activation of gluta⁃matergic neurons in the somatosensory cortex may serve as novel approaches for treating isch⁃emic vascular dementia through precise modula⁃tion of glutamatergic neuron-OPC circuits.
文摘目的研究血管性痴呆(vascular dementia,VaD)小鼠模型海马神经元的死亡机制,探讨海马神经元程序性坏死与VaD小鼠学习记忆受损之间的关系。方法慢性脑低灌注血管性痴呆小鼠模型采用双侧血管阻断法(bilateral occlusion of the common carotid arteries,2VO)构建。用Morris水迷宫检测小鼠模型学习记忆能力。用实时荧光定量PCR(qPCR)法检测动物模型海马区神经元RIPK1、RIPK3和MLKL mRNA的表达。免疫印迹法检测RIPK1、RIPK3、pRIPK3和MLKL蛋白的表达,并与小鼠模型学习记忆能力进行相关性分析。免疫荧光双标记法检测RIPK1、RIPK3和MLKL的共定位情况。结果qPCR检测发现,与假手术组相比,VaD组小鼠模型海马区神经元RIPK1、RIPK3和MLKL的mRNA表达显著增高。免疫印迹结果显示VaD组小鼠模型海马区神经元RIPK1、pRIPK3、和MLKL的蛋白表达水平明显增高。免疫荧光双标记显示在小鼠模型海马区,RIPK1、RIPK3与MLKL共表达定位显著增强。进一步研究发现,程序性坏死标志物RIPK1、RIPK3和MLKL的表达与小鼠模型目标象限停留时间及穿越平台次数呈负相关关系。结论在VaD小鼠模型中,海马神经元的丢失及其学习记忆功能障碍的发生发展,可能是通过激活RIPK1/RIPK3/MLKL信号通路,进而引起海马神经元程序性坏死所致。
文摘目的研究临床经验复方补肾活血方对慢性脑低灌注(chronic cerebral hypoperfusion,CCH)小鼠髓鞘以及认知功能的影响。方法选择30只无特定病原体级雄性C57BL/6J小鼠,按照随机数字表分为假手术组8只和手术组22只。手术组应用微弹簧双侧颈总动脉狭窄法构建CCH小鼠模型。假手术组小鼠仅分离双侧迷走神经。手术组22只小鼠术后2 d共死亡6只,其余16只成活小鼠按随机数字表法分为模型组及治疗组,每组8只。手术2周后治疗组给予补肾活血方中草药汤剂0.2 ml/d灌胃,假手术组及模型组给予等体积纯水灌胃,连续灌胃60 d。采用Morris水迷宫实验评价各组小鼠认知功能的变化,采用MRI检测弥散张量成像-分数各向异性(diffusion tensor imaging-fractional anisotropy,DTI-FA)评价小鼠脑白质病变,采用劳克坚牢蓝(Luxol fast blue,LFB)染色观察胼胝体区脱髓鞘情况,采用尼氏染色观察海马CA1区神经元损伤情况。结果与假手术组比较,模型组小鼠Morris水迷宫第5天游泳距离及逃避潜伏期显著延长、穿越平台次数、DTI-FA值、LFB染色髓鞘吸光度值、尼氏染色海马区神经元数量明显降低,差异有统计学意义(P<0.05,P<0.01);与模型组小鼠比较,治疗组Morris水迷宫第5天游泳距离[188.14(105.19,342.00)cm vs 280.22(168.47,501.37)cm,P<0.05]、逃避潜伏期第5天[10.22(5.77,19.47)s vs 19.39(13.57,31.09)s,P<0.01]显著缩短,穿越平台次数[3.00(2.00,4.00)次vs 2.00(1.00,3.00)次,P<0.05]、DTI-FA值(0.34±0.01 vs 0.31±0.01,P<0.01)、LFB染色髓鞘吸光度值[0.353(0.328,0.364)vs 0.305(0.290,0.350),P<0.05]以及尼氏染色神经元数量明显升高,差异有统计学意义[(9.94±2.22)个vs(7.11±2.02)个,P<0.01]。结论补肾活血方可以通过修复白质微结构、挽救神经元丢失,并且改善CCH小鼠的认知功能障碍。
