模式识别受体NLRC5调节血管重构的机制研究

Vascular remodeling is the major cause of atherosclerosis and in-stent restenosis. Vascular injury is able to induce vascular smooth muscle cell (VSMC) phenotype switch, proliferation and migration. This process has been considered as the important pathogenesis of vascular remodeling. Recent researches have reported that pattern recognition receptors do not only mediate innate immunity but also play a critical role in non-infectious diseases. Our preliminary work showed that one of the pattern recognition receptors NLR family members, NLRC5, was increased during intimal hyperplasia. Likewise, knockout of NLRC5 could aggravate intimal formation. In the succeeding work, we will conduct carotid artery ligation in mice to investigate the effect of NLRC5 in vascular remodeling and intimal hyperplasia based on NLRC5 knockout mice and local infection of NLRC5 overexpression adenovirus. We next perform a variety of cell and molecular experiments to determine the influence of NLRC5 on VSMC function, the interaction of NLRC5 with potential target PPARγ and the regulatory effect of NLRC5-PPARγ on downstream proteins, finding the novel mechanism of NLRC5 in non-immune cells. This study will help improve the understanding of the role and mechanism of NLRC5 in vascular remodeling, eventually providing new insights into the prevention and treatment of vascular remodeling and atherosclerosis.

血管重构是动脉粥样硬化和冠状动脉支架成形术后血管再狭窄的重要因素。血管损伤时血管平滑肌的表型改变和增殖迁移，被认为是引起血管重构的重要病理生理机制。近年来研究发现，模式识别受体除介导天然免疫应答外，也在诸多疾病中发挥重要作用。我们前期研究发现，模式识别受体NLR家族的NLRC5在小鼠颈动脉内膜增生过程中表达升高，同时NLRC5基因敲除会加重颈动脉内膜增生。申请者拟在后续工作中，利用NLRC5基因敲除小鼠及NLRC5过表达腺病毒局部感染技术，评价NLRC5对血管重构和内膜增生的影响。此外，结合多种细胞和分子生物学实验探讨NLRC5对血管平滑肌细胞功能的影响及其与潜在靶点PPARγ的相互作用，以及NLRC5-PPARγ对下游靶基因的调控作用，从而揭示NLRC5在非免疫细胞中的新机制。此研究有助于了解NLRC5对血管重构的影响及其机制，为血管重构和动脉粥样硬化的防治提供新思路。

模式识别受体NLR家族成员（NLRC5）是先天免疫中重要的免疫调节因子，参与调节炎症和抗原提呈。然而，NLRC5在血管重塑中的作用尚不清楚。本项目旨在阐明NLRC5在血管重塑中的作用，并对其潜在机制深入研究。野生型小鼠和Nlrc5敲除（Nlrc5-/-) 小鼠接受颈动脉结扎，与野生型小鼠相比，Nlrc5-/-小鼠表现出更严重的内膜增生。体外实验显示NLRC5缺乏导致人主动脉平滑肌细胞（HASMC）增殖和迁移增加，收缩型蛋白表达下降。NLRC5与PPARγ相结合。NLRC5的NACHT结构域对于与PPARγ的相互作用和刺激PPARγ活性至关重要。另外，我们也发现PPARγ激动剂吡格列酮可显著缓解Nlrc5敲除所致小鼠颈动脉过度内膜增生 并减弱NLRC5敲减的HASMC增殖和去分化。我们的研究表明，NLRC5通过与PPARγ的相互作用直接抑制血管平滑肌功能障碍，从而调节血管重塑。