祛积通络法经HIF1α/VEFG通路治疗视网膜静脉阻塞的作用机理研究

Retinal hemorrhage, macular edema and retinal ischemia induced by retinal vein occlusion (RVO)，all named assudden visual loss and fundus hemorrhage in traditional Chinesemedicine (TCM), which is the second largest blinding retinal vessels disease. Our research group previously proposed that the pathological mechanism of RVO is "luo sun ji zu", as collateral damage retinal blood, causing bleeding, wet, phlegm and qi stagnation, and thus we proposed that RVO should be treated under the principle of “qu ji tong luo”. Our previously clinical observation has been confirmed the efficacy and safety of “qu ji tong luo” in treatment of RVO, but the mechanism remains unclear. Pathogenesis of RVO in modern medicine is the dysregulation of the vein ，due to a change of the arterial vessel wall and/or due to the hypoxic surrounding tissue.Hypoxia induces hypoxia inducible factor 1α (HIF1α) hydroxylation，it can cause the upregulation of factors such as endothelin(ET-1), vascular endothelial growth factor (VEGF) and other cytokine release，that constrict veins. They may also contribute to the impairment of the blood-retinal barrier leading to oedema and in extreme cases even to hemorrhages. It was concluded that HIF1α / VEGF pathway involved in the development of RVO. However, the intervention of “qu ji tong luo” in HIF1α / VEGF pathway involved in the development of RVO disease process remains unclear. In this study, the mechanism of “qu ji tong luo” in treatment of RVO will be studied and will proposal a new idea in treatment of RVO in TCM.

视网膜静脉阻塞(RVO)引起视网膜静脉扩张伴视网膜出血、黄斑水肿或缺血，在中医学属“络损暴盲”“血症”范畴。本课题组既往提出RVO中医病机为“络损积阻”，眼底血络损伤，瘀血、水湿、痰浊、气滞共“积”，并提出“祛积通络”的治疗方法。前期临床观察证实“祛积通络法”治疗RVO的有效性，但其作用机制仍不明确。现代医学认为RVO发病机制为静脉功能性调节障碍。病变部位视网膜组织缺氧可引起缺氧诱导因子1α（HIF1α）活性增加，促进血管收缩分子 (ET-1)、血管内皮生长因子(VEGF)等因子释放，进而引起血管通透性增加、血-视网膜屏障功能破坏，最终导致视网膜出血和渗出。由此可见，HIF1α/VEGF通路参与了RVO的发生发展，而“祛积通络法”如何通过HIF1α/VEGF通路干预RVO的疾病过程仍不明确。本研究以此为切入点深入研究“祛积通络法”调控HIF1α/VEGF的作用机理。为治疗RVO提供新思路。

背景：视网膜静脉阻塞(RVO)是指视网膜静脉扩张伴视网膜出血、黄斑水肿或缺血。发病机理认为缺氧等引起静脉功能性调节障碍。VEGF 是RVO发病最关键的因子，可致血管通透性增加，加重血-视网膜屏障功能破坏；VEGF还可以诱导血管细胞粘附分子（VCAM-1）表达增强，引发白细胞停滞，加重视网膜缺血缺氧，组织缺氧时，缺氧诱导因子1α（HIF1α）去羟基化、活性增加，并促进 VEGF 等因子释放，形成恶性循环。由此可见，HIF1α/VEGF 通路参与了 RVO 的发生发展。.因此，本研究基于前期临床研究基础，认为祛积通络方可能通过调控 HIF1α/VEGF 通路，从而干预视网膜静脉阻塞疾病的发生过程。.研究内容：.拟通过建立大鼠RVO模型，进行体内实验，给予不同剂量组祛积通络方灌胃，深入研究“祛积通络方”对RVO大鼠模型视网膜组织中 HIF1α、VEGF 表达的影响，探讨其作用机制。.数据显示：1、RT-PCR显示：HIF-1α、VEGFmRNA在正常大鼠对照组有微量表达，模型组表达量明显升高，不同干预后，表达量均下降。HIF-1αmRNA的表达量，高剂量组祛积通络法与抗VEGF组相比，差异无统计学意义（P＞0.05），其余各组比较差异有统计学意义(P＜0.05)。VEGF mRNA的相对表达量，各组间比较，差异均有统计学意义(P＜0.05)。.2 免疫荧光染色和Western-Blot均显示：空白对照组视网膜组织中有少量HIF1α、VEGF 蛋白量的表达，模型组视网膜组织中HIF1α、VEGF 蛋白量的表达量明显增加，差异有统计学意义(P＜0.05)；各组治疗28d后与治疗前比较，差异均有统计学意义(P＜0.05)；高剂量祛积通络组与抗VEGF组相比，差异无统计学差异(P＞0.05)。.结果：1 微血管损伤相关因子HIF1α、VEGF、VCAM-1在RVO疾病的发生中起着关键的作用。2 祛积通络法可能通过调控RVO大鼠模型视网膜组织中HIF1α、VEGF、VCAM-1的表达，起到抑制RVO疾病发生发展的作用。3 祛积通络法对HIF1α/VEGF通路的调控是从转录水平发挥作用的。.研究意义：.祛积通络法治疗RVO模型大鼠不仅发挥了中药多靶点治疗优势，且在经济学意义上更占优势。