ILK/TRPV4调控循环血管生成细胞诱导冠脉微血管再生的机制研究

Ischemic heart disease (IHD) is a major public health problem which threats to human health in the world. Promoting the regeneration of coronary microvessels and improving the microcirculation of the myocardium is the key to the treatment of ischemic heart disease. Under the stimulus of physiological or pathological factors, circulating angiogenic cell (CAC) can migrate to the injury site where they participate in revascularization. However, the lower vitality of CAC in vivo makes cell transplantation stay in the experimental stage. In the previously study, we found that the gel culture method can obtain highly viable CAC in vitro. Based on this result, we analyzed the protein expression profile between Gel and classic cultured CAC and found that activation of adhesion-related signaling pathway, especially Integrin-linked kinase (ILK) is the key factor to improve the activity of CAC. Further experiments confirmed that TRPV-Ca2+ ion channels are involved in promoting activity of CAC. Therefore, based on the previous study, we intended to elucidate the molecular mechanism by which ILK regulates the activity of CAC in regulating TRPV4 ion channels, and further confirm ILK/TRPV4 activation can replace the adhesive property of the gel matrix for improving the activity of CAC by using the rat model. We expect to significantly improve the therapeutic effect of CAC transplantation through this project.

缺血性心脏病是威胁人类健康的头号杀手。促进冠脉微血管再生、改善心肌微循环是治疗关键环节。循环血管生成细胞（CAC）在病理或生理刺激下可从骨髓动员至损伤处促进血管新生而成为治疗缺血性心脏病的研究热点之一，然而体内活力较低是CAC移植滞留于实验阶段的重要原因。前期工作中，课题组从已明确的凝胶培养方式可获得体外活性较高的CAC这一现象入手，通过比对分析凝胶培养/经典培养方式下CAC蛋白的表达谱，发现黏附相关信号的激活是提高CAC活性的关键，而整合素连接激酶（ILK）是其中的关键因子；进一步实验证实，能够感受机械力信号的TRPV-Ca2+离子通道参与了黏附促进的CAC活性提升。因此，本项目拟在前期基础上，阐明ILK通过调控TRPV4离子通道从而调控CAC活性的分子机制，并通过大鼠实验模型证实ILK/TRPV4的激活取代凝胶基质产生的黏附作用，提高体内CAC的活性，从而大幅提升CAC移植的治疗效果。

缺血性心脏病是威胁人类健康的头号杀手。促进冠脉微血管再生、改善心肌微循环是治疗关键环节。循环血管生成细胞（CAC）在病理或生理刺激下可从骨髓动员至损伤处促进血管新生而成为治疗缺血性心脏病的研究热点之一，然而体内活力较低是CAC移植滞留于实验阶段的重要原因。本研究基于开胸高位结扎左冠状动脉前降支建立大鼠急性心肌梗死（AMI）模型以及细胞模型，结合分子生物学、影像学等手段对ILK/TRPV4调控CAC的机制进行了探索，通过研究发现：1、ILK过表达或TRPV4激动剂促进了人脐静脉内皮细胞（HUVEC）与CAC共培养的血管生成。ILK过表达或激活上调了CACs中TRPV4的表达，而TRPV4激动剂刺激也调节ILK的表达。说明ILK通过调控TRPV4的激活从而调控CAC的生物学活性。2、ILK/TRPV4的激活可以增强CAC在血管生成中的活性，抑制心肌间质纤维化，防止心肌细胞凋亡，最终改善AMI大鼠心功能。3、CAC中TRPV4的表达增加是ILK/TRPV4激活介导的血管生成的关键调节因子。CAC活性的提高，尤其是其体内生物活性的提高，将有利于细胞移植的疗效及其临床应用。