丹酚酸类化合物对缺血性脑卒中血脑屏障保护作用和分子机制研究

Ischemic stroke is a sever cerebrovascular disease. On the initial of ischemic stroke, the MMP/TIMP balance was destroyed. First of all, MMP-9 was overexpression in neutrophil cells, vascular endothelial cells and neurons. Then MMP-2 and MMP-3 were overexpression in star glial cells and glial cells. The large amount of MMPs could further induce the hydrolysis of membrane protein, destroy the blood brain barrier, increase neutrophil cell infiltration and induce neuro-inflammation. As a results, the brain infarct area was significantly expanded. So it was of great significance to discover novel MMP-9 inhibitors for the treatment of ischemic stroke..Previous study and literature research showed that salvianolic acids could inhibit MMP-9 activity significantly both in vivo and in vitro. This project will evaluate the MMP-9 inhibitory effects of a series of salvianolic acids. After taking into consideration the pharmacokinetic properties, blood brain barrier protective effects and the action mechanism of these inhibitors, their therapeutic effects would be carefully confirmed on animal models in order to find a novel promising candidate compound on ischemic stroke.

缺血性脑卒中是严重的脑血管疾病。脑缺血时，神经血管单元中的MMP/TIMP系统平衡被破坏，中性粒细胞、血管内皮细胞和神经元高表达MMP-9；随后星形胶质细胞、小胶质细胞和周细胞高表达MMP-2和MMP-3；高表达的MMPs继而活化和水解基膜蛋白，破坏血脑屏障，加剧中性粒细胞浸润以及诱导神经炎性反应和神经元损伤，使梗死面积不断扩大。因此，研究MMP-9抑制剂对于开发高效的抗缺血性脑卒中的药物具有非常重要的意义。.申请者的前期研究和文献调研表明，丹酚酸类化合物在体内外均具有明显的MMP-9抑制活性。本项目将在体内外评价一系列丹酚酸类化合物的MMP-9抑制作用，进行血脑屏障的保护作用和分子机制研究，并在整体动物水平对其脑缺血治疗的疗效进行确证，期待发现新型高效的抗脑卒中候选化合物。

基质金属蛋白酶的主要的生物学功能是降解细胞外基质蛋白质。在众多基质金属蛋白酶中，MMP-9在脑卒中的病理发展过程中起着关键作用。MMP-9的表达或活性增高都会损伤血脑屏障，进而会损伤神经血管单元的完整性，造成严重的脑损伤。丹参是一种广泛应用于心脑血管系统疾病治疗的传统药物，丹酚酸类化合物是其中的主要一类活性物质。本项目立足于丹酚酸类化合物的MMP-9抑制活性，对其血脑屏障保护作用进行系统的评价，并在整体动物水平对其进行脑缺血治疗的疗效确证，期待发现新的抗脑卒中候选化合物。本项目研究表明，丹酚酸A、B、C和D在体外酶活性抑制模型和体内脑缺血再灌注动物模型中均表现出明显的MMP-9抑制活性。丹酚酸类化合物能够改善大鼠脑缺血再灌注引起的神经功能损伤症状，延长脑缺血再灌注大鼠在倾斜板上的停留时间，显著减小脑缺血后大鼠脑水肿百分比，减小脑缺血大鼠脑梗死体积，降低脑组织中伊文思蓝的渗出，并且能够抑制紧密连接蛋白ZO-1、claudin-5和occludin的降低，从而维持血脑屏障完整性。本项目有利于以血脑屏障保护为切入点的抗脑缺血药物的研发，具有重要的意义。