动静脉短路所致的高切应力通过YAP-JNK信号通路减轻动脉支架内再狭窄的机制研究

Stent restenosis (ISR) seriously affects the effect of stent implantation. Low shear stress can promote the intimal hyperplasia and inflammatory response in the stent segment and lead to the occurrence of ISR. Laminar shear stress can promote the phosphorylation of Yes related protein (YAP), inhibit its transportation to the nucleus, and weaken the downstream c-Jun N-terminal kinase (JNK) signal transduction and the expression of related inflammatory genes, thereby inhibit the proliferation of endothelial cells and inflammation. Our preliminary experiments showed that arteriovenous shunt could increase laminar shear stress and relieve intimal hyperplasia after balloon dilatation, while YAP play an important role. Therefore, a hypothesis is put forward: arteriovenous shunt in the distal arterial segment of the stent can increase the laminar shear stress of stent segment, and alleviate the intimal hyperplasia and inflammation through YAP-JNK signaling pathway, thereby reduce ISR. To test this hypothesis, we will use the methods such as the parallel plate flow chamber system, a specific inhibitor of JNK, gene knockout mediated by viral vector transfection and fluorescence quantitative PCR method, from the aspects of molecular, cell, tissue and whole animal level, to study the mechanism of the reduction effect on ISR of high shear stress achieved by arteriovenous shunt via YAP-JNK pathway, thus provide a new idea and a new method for further research on mechanism and prevention of the occurrence of ISR.

支架内再狭窄(ISR)严重影响着动脉支架植入治疗的效果。低切应力会促进支架段动脉内膜增生和炎症反应，导致ISR的发生。层流切应力能促进Yes相关蛋白(YAP)磷酸化，抑制其向核内转移，减弱下游c-Jun 氨基末端激酶(JNK)信号传导和相关炎症基因的表达，从而抑制内皮细胞的增殖和炎症。我们预实验发现动静脉短路法可以增高层流切应力、减轻球囊扩张术后动脉内膜增生，而YAP发挥了重要作用。因此提出假说：支架远端行动静脉短路术可以增高支架段动脉层流切应力，并通过YAP-JNK信号通路减轻内膜增生和炎症，从而减轻ISR。为验证这一假说，我们将应用平行平板流动腔系统、JNK特异性抑制剂、病毒载体转染基因敲除、荧光定量PCR等手段，从分子、细胞、组织及动物整体水平等多方面探讨动静脉短路法所致的高切应力减轻ISR的机制，从而为ISR 发生机制和预防方法研究提供一种新思路和新方法。

支架内再狭窄严重影响着动脉支架植入治疗的效果。低剪切力会促进支架段动脉内膜增生和炎症反应，导致支架内再狭窄的发生，而层流切应力可以抑制内皮细胞的增殖和炎症。本研究用不同强度的流体切应力刺激内皮细胞，研究高剪切力对内皮细胞增殖的影响；用动静脉短路法来增高动脉内的剪切力，来研究其对球囊损伤诱导的动脉内膜增生的影响；及其对动脉支架植入后内膜增生的影响。高流体切应力通过调节VCAM-1、JNK和YAP的表达和激活促进内皮细胞的增殖；动静脉短路可以增加动脉腔内剪切力、减少平滑肌细胞表型向合成型的转变、减轻YAP、pJNK和VCAM1的表达，从而减轻球囊损伤诱导的内膜增生；动静脉短路所致的高剪切力减轻了支架植入后的内膜增生，其潜在机制可能与调节eNOS、VCAM-1、p38和JNK的表达和激活有关。