苁蓉散通过抑制内质网应激减少AD模型大鼠海马神经元细胞凋亡

Cong Rong San mitigates rat hippocampal neuronal apoptosis in an Alzheimer disease model by inhibition of endoplasmic reticulum stress

目的:探究苁蓉散(Cong Rong San,CRS)对阿尔茨海默病(Alzheimer disease,AD)模型大鼠神经元损伤及内质网应激(endoplasmic reticulum stress,ERS)的影响。方法:将60只SD雄性大鼠(2月龄)随机分为对照组、模型组、低剂量CRS组、中剂量CRS组、高剂量CRS组和盐酸美金刚组。Morris水迷宫实验检测大鼠的学习记忆能力;HE和尼氏染色观察大鼠海马CA1区的神经元形态;透射电镜观察大鼠海马的内质网形态;TUNEL染色观察大鼠海马CA1区神经元的凋亡情况;Western blot实验检测大鼠海马中葡萄糖调节蛋白78(glucose-regulated protein 78,GRP78)、B细胞淋巴瘤2(B-cell lymphoma-2,Bcl-2)、Bcl-2关联X蛋白(Bcl-2-ssociated X protein,Bax)、caspase-3及通路蛋白蛋白激酶R样内质网激酶(protein kinase R-like endoplasmic reticulum kinase,PERK)、p-PERK、激活转录因子4(activating transcription factor 4,ATF4)和C/EBP同源蛋白(C/EBP homologous protein,CHOP)的表达。结果:与模型组比较,中、高剂量的CRS能有效提高大鼠学习记忆能力,减少神经元的丢失,抑制ERS通路PERK-ATF4-CHOP的发生,减少海马中凋亡蛋白Bax和caspase-3的表达,增加海马中抗凋亡蛋白Bcl-2的表达。结论:CRS可以减轻AD大鼠认知损伤、海马神经元的损伤和神经元凋亡,其机制可能是抑制了ERS。

AIM:To investigate the effects of Cong Rong San(CRS)on neuronal injury and endoplasmic reticulum stess(ERS)in rat models of Alzheimer disease.METHODS:Sixty male Sprague-Dawley rats(2 months old)were randomly divided into control(CON),model(MOD),low-dose CRS(CRSD),medium-dose CRS(CRSZ),highdose CRS(CRSG),and memantine hydrochloride(MJG)groups.Morris water maze experiments were used to assess learning and memory in the rats.The morphology of neurons in the CA1 region of the hippocampus was examined using HE and Nissl staining,and the morphology of the endoplasmic reticulum in hippocampal cells was observed by transmission electron microscopy.Neuronal apoptosis in the CA1 region of the hippocampus was evaluated by TUNEL staining,while Western blot was used to assess the protein expression of glucose-regulated protein 78(GRP78),B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),caspase-3,protein kinase R-like endoplasmic reticulum kinase(PERK),p-PERK,activating transcription factor 4(ATF4)and C/EBP homologous protein(CHOP)in rat hippocampal tissues.RE⁃SULTS:Compared with those in the MOD group,rats in the CRSZ and CRSG groups showed improved learning and memory,together with reduced hippocampal neuronal loss,PERK-ATF4-CHOP activity,and the expression of the pro-apoptotic proteins Bax and caspase-3,while the expression of the anti-apoptotic protein Bcl-2 was increased.CONCLUSION:Treatment with Cong Rong San was found to mitigate cognitive impairment,as well as damage and apoptosis in hippocampal neurons,in rat models of Alzheimer disease,possibly by inhibition of endoplasmic reticulum stress.