易损As斑块病理性血管新生的新机制：MPO介导HK1硝基化修饰促血管内皮细胞线粒体自噬

髓过氧化物酶MPO是蛋白质硝基化修饰关键酶，高表达于易损As斑块，与急性心血管临床事件密切相关，但机制未明。本项目前期研究发现血管新生过程己糖激酶1（HK1）硝基化修饰水平升高，预实验证明敲减MPO下调血管内皮细胞（VEC）HK1硝基化修饰与线粒体自噬；硝基化修饰HK1促VEC增殖与线粒体自噬，自噬抑制剂抑制其诱导的细胞增殖。由此提出假说：MPO促HK1硝基化修饰，介导As斑块内VEC线粒体自噬，致细胞过度增殖与病理性血管新生，加速易损斑块形成。为证实该假说，本项目拟采用行颈动脉串联结扎手术的apoE-/-小鼠以及三维培养的VEC探讨并验证MPO是否通过HK1硝基化修饰促VEC线粒体自噬与过度增殖，并结合慢病毒转染、MRM质谱、电镜等方法技术探讨“MPO-硝基化修饰HK1-线粒体自噬”途径促病理性血管新生与易损As斑块形成的调控机制。本研究的完成将为临床上稳定As斑块提供新的思路和靶点。

Myeloperoxidase (MPO), a key enzyme for protein tyrosine nitration expressed highly in vulnerable atherosclerosis (As) plaque, is closely related to acute clinical cardiovascular events. However the underlying mechanisms are still unclear. Our previous experiments revealed that hexokinase 1 (HK1) expressed highly during angiogenesis, Preliminary experiments found that knockdown of MPO could reduce HK1 nitration and mitophagy in vascular endothelial cells (VEC), nitrated HK1 could promote VEC mitophagy and proliferation, autophagy inhibitors inhibited VEC proliferation. Thus, we propose that “MPO-induced nitrated HK1 promotes VEC mitophagy, which leading to VEC proliferation, pathologic angiogenesis and accelerated As vulnerable plaque formation”. To confirm this hypothesis, we will use high-fat diet fed apolipoprotein E-deficient mice with tandem stenosis to the carotid artery and 3-dimension cultured HUVECs to explore and verify whether or not MPO promote HK1 nitration and VEC mitophagy. Then, we will explore the potential mechanism of pathologic angiogenesis and As vulnerable plaque formation in the way of “MPO-nitro-HK1-matophagy” by using lentiviral transfection, multiple-reaction-monitor mass spectrum and electron microscope et al. The accomplish of this study will provide new idea and target for As plaque stabilization.