基于周细胞募集信号探讨补阳还五汤维持血脑屏障完整性防治Alzheimer病的机制

The incidence of Alzheimer’s disease (AD) is increasing, seriously threatening human health. Due it to be difficult to reverse during clinical stage, it is indispensible to early treatment. Preclinical AD (PCAD) has become the focus of attention. It is an important case in PCAD that lost Pericytes lead to high permeability of Blood-Brain Barrier (BBB), The new pathway of the prevention and treatment of AD is that recruitment of Pericytes maintained the integrity of the BBB. Recent studies show that bFGF-FGFR/PDGFB-PDGFRβ signal pathway is a key start signal of early recruitment of Pericytes. Qi and blood stasis through AD, Yiqihuoxue Recipe Buyanghuanwu decoction can improve the cognitive function of AD patient , Previous studies demonstrated that it can reduce permeability of BBB. Therefore, the hypothesis of early preventing and treatment AD is suggested that Buyanghuanwu decoction regulate bFGF-FGFR/PDGFB-PDGFRβ signal pathway and then recruit Pericytes to maintain integrity of BBB. Establish AD model that used SAM-P/8 mice and use three-dimensional culture model of vascular rings and establish Pericyte –endothelial cell co-culture system, to observe the influence of Buyanghuanwu decoction on integrity of BBB and infulence of key nodes of recruitment pathway of Pericytes. Clarify Buyanghuanwu decoction maintain the integrity of BBB through recruitment of Pericytes , Provide the foundation of molecular biology for TCM early prevention and treatment of AD.

Alzheimer病（AD）发病率逐年升高，严重威胁人类健康。其临床阶段病变难以逆转，故早期干预至关重要，临床前期AD（PCAD）成为关注重点。周细胞缺如致血脑屏障（BBB）通透性增高是PCAD的重要事件，募集周细胞维持BBB完整性为AD早期防治新途径。近期发现，bFGF-FGFR/PDGFB-PDGFRβ为周细胞募集关键始动信号。气虚血瘀贯穿AD，益气活血方药补阳还五汤可改善AD认知功能，且课题组前期研究表明其可降低BBB通透性。据此提出补阳还五汤调控bFGF-FGFR/PDGFB-PDGFRβ信号募集周细胞，维持BBB完整性防治早期AD假说。课题拟用SAM-P/8小鼠复制AD模型、采用血管段三维培养模型、构建周细胞-内皮细胞共培养体系，从在体、离体层面考察该方药对BBB完整、周细胞募集通路关键节点的影响，阐明该方药募集周细胞维持BBB完整性的机制，为中医药早期防治AD奠定分子基础。

研究背景：Alzheimer病（AD）发病率逐年升高，严重威胁人类健康。其临床阶段病变难以逆转，故早期干预至关重要，临床前期AD（PCAD）成为关注重点。周细胞缺如致血脑屏障（BBB）通透性增高是PCAD的重要事件，bFGF-FGFR/PDGFB-PDGFRβ为周细胞募集关键始动信号。募集周细胞维持BBB完整性为AD早期防治新途径。气虚血瘀贯穿AD，益气活血方药补阳还五汤可改善AD认知功能，且课题组前期研究表明其可降低BBB通透性。故提出补阳还五汤调控bFGF-FGFR/PDGFB-PDGFRβ信号募集周细胞，维持BBB完整性防治早期AD假说。.主要内容：本项目研究以“SAM-P/8小鼠BBB损伤模型”为研究对象，在整体水平探讨补阳还五汤维持BBB完整性、改善认知功能的作用机制；采用“内皮细胞-周细胞血管新生三维培养模型”，在离体水平上阐明补阳还五汤维持新生微血管完整的作用机制；建立“周细胞-内皮细胞共培养体系”，在细胞水平上阐明补阳还五汤促进周细胞募集的作用机制。.重要结果：补阳还五汤上调bFGF、PDGFB、PDGFRβ，促进周细胞募集，促进新生血管形成，进而维持BBB完整，改善SAM-P/8小鼠认知功能，其中PDGFRβ可能为补阳还五汤调控周细胞的作用靶点。.关键数据：1.补阳还五汤降低SAM-P/8小鼠逃避潜伏期的时间，增加穿越平台次数，延长停留时间；减少EB含量，降低BBB通透性；上调bFGF、PDGFB、Mfsd2a蛋白表达，提高周细胞覆盖率，维持BBB完整，降低Aβ含量，改善认知障碍。2.补阳还五汤上调bFGF、PDGFβ基因水平以及PDGFRβ蛋白表达，维持新生血管生长时间，增加新生血管成熟数量。3.补阳还五汤促进周细胞活性增殖、增加迁移距离、增加趋化周细胞的数量，增加内皮细胞分泌bFGF、PDGFβ的含量，上调内皮细胞bFGF、PDGFβ和周细胞Rho、Rac1基因水平，以及周细胞PDGFRβ蛋白表达；使用PDGFRβ抑制剂后，周细胞Rho基因水平、Rac1蛋白水平不受药物调控。.科学意义：本课题研究明确补阳还五汤对阿尔茨海默病早期阶段可维持BBB完整，改善BBB损伤的阿尔茨海默病小鼠的认知功能。为中医药防治老年痴呆提供实验依据以及防治思路。