黄芪甲苷和阿魏酸改善慢性肾脏病肾脏微血管内皮细胞通透性的协同作用机制

The impairment of vascular endothelial cell is regarded as an important factor in the progression of chronic kidney diseases (CKD) by Chinese and western medicine. Dysfunction of any component of capillary barrier, including the endothelial glycocalyx, intracellular junction or intercellular cytoskeleton protein, can disrupt normal microvascular permeability, which results in proteinuria, interstitial inflammation and hypoxia. Many kinds of Chinese herbs, including Astragali and Angelica, have been used to treat kidney diseases in China for hundreds of years. Astragloside IV and Ferlic acid were two ingredients from the decoction of Astragali and Angelica (A&A). The combination of Astragloside IV and Ferlic acid (AF) was proved to be the main active fraction of A&A due to its similar antifibrotic effects to A&A. AF was found to improve endothelial cell dysfunction characterized by enhancement of nitric oxide production. Recently it was found to reduce urinary protein excretion. And several research works supported that Astragloside IV or Ferlic acid could inhibit the intercellular calcium influx and disassembly of cytoskeleton, which related to improvement of endothelial cell barrier. Thus to the least extent, the renal protective effects of AF partly depends on the improvement of endothelial cell function. In this study, 5/6 nephrectomy and diabetic nephropathy are employed to determine the optimal compatibility program of Astragloside IV and Ferlic acid to improve renal function. The impact of the compatibility-dose combination of Astragloside IV and Ferlic acid on the endothelial permeability,including dextran permeability, thickness of the capillary endothelial surface layer, the expression of cell junction proteins and cytoskeletal protein, will be observed in the dynamic animal experiments to explore the relationship between endothelial permeability and proteinuria,inflammation and hypoxia in kidney. In vitro, renal microvascular endothelial cells will be used to explore the target of AF in improving endothelial permeability via two kinds of cellular signal pathways, including the factors to increase cell-cell adhesion and stabilize endothelial barrier (PKA, Rac1, Rap1) and the factors to disrupt cell-cell adhesion and break endothelial barrier (PKCα, RhoA). The study is designed to clarify the synergy mechanisms of Astragaloside IV and Ferulic acid in retarding the progression of CKD, in order to provide the modern medicine theoretical basis to the future clinical practice of traditional Chinese herbs.

中西医均认为血管内皮细胞损伤在慢性肾脏病（CKD）进展中起着重要作用。肾脏微血管内皮细胞表层糖萼、细胞间连接或细胞内骨架蛋白遭到破坏时，内皮细胞通透性增高可导致蛋白尿的发生及肾组织炎症反应和缺氧。黄芪甲苷、阿魏酸的组合物能减轻蛋白尿和延缓CKD进展；还可抑制细胞内游离钙和细胞骨架重排，有可能改善内皮细胞屏障功能。本研究将利用5/6肾切除和糖尿病肾病两种模型确定黄芪甲苷和阿魏酸改善肾功能的最佳配伍方案，动态观察该配伍剂量的组合物对内皮细胞通透性（葡聚糖通透性、细胞表层厚度、细胞连接蛋白和细胞骨架蛋白表达）的影响与蛋白尿和肾脏炎症及缺氧的关系；利用体外培养的肾脏微血管内皮细胞，从促进细胞连接聚合和解离两方面因素（PKA、Rac1、Rap1及PKCα、RhoA）着手，探讨其影响内皮细胞通透性的作用靶点和环节，以期阐明两有效组分在延缓CKD进展中的协同作用机制，为复方中药应用提供现代医学理论依据。