基于IRE1α介导的内质网应激信号通路探讨补肾益智方防治阿尔茨海默病的分子机制

Alzheimer disease (AD) threatens the physical and mental health of patients.The pathogenesis of AD is complex. Prevention and control of AD has become a common concern of society. Endoplasmic reticulum stress (ERS) is closely related to neuronal apoptosis and plays an important role in the occurrence and development of AD. Previous studies have found that Bushen Yizhi Decoction can improve the cognitive function and quality of life of patients with mild cognitive impairment. Part of its mechanism may be related to the inhibition of IRE1 alpha to reduce the degree of ERS in nerve cells, thereby Anti-apoptosis of nerve cells. Therefore, it is hypothesized that Bushen Yizhi Recipe can inhibit the apoptosis of neurons induced by AD by reducing ERS mediated by IRE1 alpha, and then exert its anti-AD effect. In this study, we will take IRE1α signaling pathway as a starting point, through regulating IRE1 alpha pathway to inhibit Aβ-42-induced neuronal endoplasmic reticulum stress by Bushen Yizhi Recipe, and clarify the regulation of Bushen Yizhi Recipe on endoplasmic reticulum stress and IRE1α pathway in AD rats.

阿尔茨海默病（Alzheimer disease，AD）威胁患者身心健康，发病机制复杂，防控AD已经成为社会普遍关注的问题。内质网应激（endoplasmic reticulum stress，ERS）与神经细胞凋亡密切相关，在AD发生发展中发挥重要作用。前期研究发现补肾益智方具有改善轻度认知障碍患者认知功能和生活质量的作用，其部分机制可能与通过抑制IRE1α减轻神经细胞中ERS程度，从而抗神经细胞凋亡有关。故提出假说：补肾益智方通过减轻IRE1α介导的ERS，抑制AD所诱导的神经细胞凋亡，进而发挥抗AD效应。本课题将以IRE1α介导的ERS信号通路为切入点，研究补肾益智方调控IRE1α通路抑制Aβ1-42诱导下神经细胞内质网应激的作用，并阐明补肾益智方对AD大鼠脑组织内质网应激及IRE1α通路的调控作用。

项目背景：补肾益智方用于治疗阿尔茨海默病（AD），但具体作用机制有待进一步探讨。.研究内容：使用不同剂量补肾益智方和Aβ处理大鼠嗜铬细胞瘤细胞（P12）和人神经母细胞瘤细胞（SH-SY5Y）。观察细胞形态，以确定细胞损伤情况。分别采用CCK-8和流式细胞术检测细胞活性和细胞凋亡/细胞周期。采用Western blot、免疫组化或qRT-PCR检测内质网应激相关蛋白（GRP78和CHOP）、p-IRE1α、IRE1α、ASK1、p-JNK、JNK、Bax、Bcl-2、XBP-1及Bim的表达水平。采用Fura-2/AM测定细胞内Ca2+浓度。SD大鼠海马CA1区注射Aβ构建AD模型，然后连续使用不同剂量补肾益智方灌胃14d。Morris水迷宫实验用于测试大鼠学习记忆能力。采用H&E和TUNEL染色检测脑组织病理学变化。.重要结果：补肾益智方或IRE1α沉默可缓解Aβ诱导的细胞损伤，降低细胞活性，增强细胞凋亡，诱导G0/G1期细胞周期停滞，促进GRP78、CHOP、p-IRE1α、p-JNK、Bax、XBP-1、Bim表达增加，Bcl-2表达减少。此外，Aβ可抑制大鼠学习记忆能力，而补肾益智方可减轻Aβ的作用，补肾益智方也可治疗Aβ所致的脑神经细胞损伤。.科学意义：补肾益智方能够通过调节IRE1α信号通路减轻内质网应激，对AD产生治疗效果。