【摘要】 背景:线粒体动力学异常已被证实与阿尔茨海默病的发生密切相关,课题组前期研究发现,法舒地尔具有神经保护作用,但其是否对线粒体动力学具有调控作用尚未明确。目的:探究ROCK抑制剂法舒地尔对阿尔茨海默病小鼠认知功能、神经元凋亡的影响以及可能的调控机制。方法:将淀粉样前体蛋白/早老素1(APP/PS1)小鼠随机分为法舒地尔组[25 mg/(kg·d)]和生理盐水组,腹腔注射治疗2个月,并以C57BL/6野生型小鼠作为正常对照。应用Morris水迷宫和Y迷宫测试评价小鼠空间认知功能,尼氏染色检测神经元数量与形态,TUNEL染色观察神经元凋亡情况,Western blot法检测海马组织NeuN、Bax、Bcl-2、Cleaved Caspase-3、动力相关蛋白1(DRP1)、线粒体分裂蛋白1(FIS1)、视神经萎缩因子1(OPA1)、线粒体融合蛋白1(Mfn1)、线粒体融合蛋白2(Mfn2)的表达,免疫荧光染色检测NeuN、动力相关蛋白1表达。结果与结论:(1)法舒地尔干预明显改善APP/PS1小鼠损伤的认知障碍,提高其学习、记忆和探索功能;(2)与正常对照组相比,APP/PS1小鼠神经元数量减少,凋亡率增加,海马组织成熟神经元标志物(NeuN)及抗凋亡蛋白(Bcl-2)表达减少,促凋亡蛋白(Bax、Cleaved Caspase-3)表达增加,法舒地尔治疗组得到明显改善;(3)法舒地尔减少线粒体分裂蛋白(动力相关蛋白1、线粒体分裂蛋白1)表达,增加线粒体融合蛋白(视神经萎缩因子1、线粒体融合蛋白1、线粒体融合蛋白2)表达;(4)结果说明,法舒地尔具有改善APP/PS1小鼠认知的功能,其机制可能与修复线粒体分裂-融合失衡进而抑制神经元凋亡有关。更多还原

【Abstract】 BACKGROUND: The pathogenesis of Alzheimer’s disease is closely related to abnormal mitochondrial dynamics. Our previous research demonstrated that Fasudil has neuroprotective effect. However, it is needed to explore whether Fasudil has beneficial effect on regulating mitochondiral dynamics.OBJECTIVE: To investigate the effect and mechanism of ROCK inhibitor on cognitive function and neuronal apoptosis in Alzheimer’s disease mice.METHODS: Amyloid precursor protein/presenilin-1(APP/PS1) transgenic mice were randomly divided into the Fasudil group(25 mg/kg/d) and normal saline group(equivalent volume normal saline), and wild-type C57 BL/6 mice at the same age and gender served as normal controls(same volume normal saline).Administration in each group was given via intraperitoneal injection once daily for 2 months. Spatial cognition of mice was detected by Morris water maze test and Y maze test. Nissl staining was used to observe and analyze the number and morphology of neurons. TUNEL staining was applied to observe neuronal apoptosis. The protein levels of NeuN, Bax, Bcl-2, Cleaved Caspase-3, dynamin-related protein 1(DRP1), mitochondrial fission protein 1(FIS1), optic atrophic protein 1(OPA1), mitofusin 1(Mfn1), and mitofusin 2(Mfn2) in hippocampus tissue were determined by western blot test. The expression of NeuN and DRP1 was detected by immunofluorescence staining.RESULTS AND CONCLUSION: Fasudil ameliorated cognitive impairment and improved loss of learning, memory and exploration function in APP/PS1 mice.Compared with the normal control group, the number of survived neurons was decreased, the apoptotic rate of neurons was increased, the expression of Bax and Cleaved Caspase-3 was increased, but the expression of NeuN and Bcl-2 was decreased in APP/PS1 mice. These changes were all strongly reversed by a 2-month treatment of Fasudil. Fasudil markedly down-regulated the expression of DRP1 and FIS1, but remarkably up-regulated the expression of OPA1, Mfn1,and Mfn2. These findings indicate that Fasudil significantly improves the spatial cognitive function in APP/PS1 mice, which may be related to restoring the mitochondrial fission and fusion imbalance so as to inhibit neuronal apoptosis.更多还原