CX3CL1通过抑制小胶质细胞焦亡改善阿尔茨海默病小鼠的神经元功能

CX3CL1 improves neuronal function in mice with Alzheimer’s disease by inhibiting microglial pyroptosis

摘要:

目的 通过外源性注射趋化因子（C-X3-C基序）配体1（Fractalkine，CX3CL1）探索其对阿尔茨海默病（Alzheimer’s disease，AD）小鼠神经元功能的影响及机制。方法 采用APP/PS1双转基因小鼠建立AD模型。将小鼠随机分为4组：对照组、AD模型组、AD+PBS溶剂组、AD+CX3CL1组。AD+CX3CL1组颅内给予CX3CL1。AD+PBS溶剂组注射等容积的PBS溶剂。采用旷场实验和Morris水迷宫测试小鼠认知行为，免疫荧光染色、TUNEL染色、尼氏染色、蛋白质印迹和RT-PCR技术对小鼠海马组织进行分析。结果 ①AD小鼠接受CX3CL1注射后增加了移动距离，但没有显著差异（P=0.189）；在水迷宫测试中，AD+CX3CL1组寻找水下平台的移动距离显著缩短（P=0.001）；②AD模型组中GSDMD（Gasdermin D）蛋白和炎症相关蛋白表达显著升高（P<0.05），而CX3CL1注射能显著降低这些蛋白的表达水平（P<0.05）；③AD模型组的尼氏体数量、突触相关蛋白25 kDa（synaptosomal-associated protein of 25 kDa，SNAP25）、突触后致密区蛋白95（post synaptic density protein 95，PSD95）和囊泡相关膜蛋白1（vesicle-associated membrane protein 1，VAMP1）表达水平显著降低，而CX3CL1组尼氏体数量（P=0.001）和SNAP25、PSD95、VAMP1蛋白的表达增加（P=0.043，P=0.026，P=0.003）。结论 外源性CX3CL1注射能够通过调节炎症因子和减少细胞焦亡来改善AD小鼠的神经元功能，保护神经元免受损伤。

Abstract:

Objective To investigate the effect of exogenous injection of chemokine C-X3-C-motif ligand 1（CX3CL1） on neuronal function in mice with Alzheimer’s disease（AD） and its mechanism.Methods APP/PS1 double transgenic mice were used to establish a model of AD，and the mice were randomly divided into control group，AD model group，AD+PBS group，and AD+CX3CL1 group. The mice in the AD+CX3CL1 group were given intracranial administration of CX3CL1，and those in the AD+PBS group were injected with an equal volume of PBS solvent. The open field test and the Morris water maze test were used to assess the cognitive behavior of mice，and immunofluorescent staining，TUNEL staining，Nissl staining，Western blotting，and RT-PCR were used to analyze hippocampal tissue.Results The AD mice receiving CX3CL1 injection showed an increase in movement distance，but without a significant difference（P=0.189）；however，in the water maze test，the AD+CX3CL1 group showed a significant reduction in the movement distance to reach the submerged platform（P=0.001）. The AD model group had significant increases in the expression levels of gasdermin D and inflammation-related proteins（P<0.05），while CX3CL1 injection significantly reduced the expression levels of these proteins（P<0.05）. The AD model group had significant reductions in the number of Nissl bodies and the expression levels of （synaptosomal-associated protein of 25 kDa（SNAP25），post synaptic density protein 95（PSD95），and vesicle-associated membrane protein 1（VAMP1），while the CX3CL1 group showed significant increases in the number of Nissl bodies（P=0.001） and the expression levels of SNAP25，PSD95，and VAMP1（P=0.043，0.026，and 0.003）.Conclusion Exogenous CX3CL1 injection can improve neuronal function and protect neurons from damage in AD mice by regulating inflammatory factors and reducing pyroptosis.