RUNX1调控CASC9转录介导PVAT炎症影响冠状动脉粥样硬化斑块稳定性的作用机制研究

The regulatory mechanism of perivascular adipose tissue (PVAT) inflammation leads to decreased stability of coronary plaque leading to ACS remains unclear. Our previous studies showed that PVAT inflammation in ACS patients could be quantitatively determined in vivo by spectral CT, and the expression of MMP-2 in serum of ACS patients was increased. On the basis of biological information network and qRT-PCR verification, we found that the expression of both CASC9 and MMP-2 were up-regulated in endothelial cells when PVAT was in an inflammatory state, and miR-488-3p targeted binding to them was down-regulated, which had potential ceRNA regulatory relationship. Besides, we found that RUNX1 could target the promoter region of CASC9 and positively regulate the expression of CASC9. Therefore, we hypothesized that PVAT inflammation could reduce plaque stability though ceRNA pathway of CASC/ mir-488-3p/MMP-2 transcriptionally activated by RUNX1. The present project intends to use overexpression/silencing technology, in vitro cell model and clinical study to elucidate the mechanism of RUNX1 transcriptional activation the ceRNA pathway of CASC9/ mir-488-3p/MMP-2 to regulate the stability of plaques in ACS patients with PVAT inflammation detected by spectral CT in vivo, so as to provide theoretical guidance for the early identification of unstable plaques and the search for new therapeutic targets.

血管周围脂肪组织（PVAT）炎症引起冠脉斑块稳定性减低导致ACS的调控机制不明。申请人前期发现ACS患者PVAT炎症可通过光谱CT在体定量测定，且其血清中MMP-2表达增高。通过生物信息网及qRT-PCR验证，我们发现：PVAT炎症时内皮细胞中CASC9和MMP-2上调，与二者靶向结合的miR-488-3p下调，有潜在ceRNA调控关系；同时CASC9启动子区与RUNX1有结合位点，RUNX1对CASC9具有正向调控。推测RUNX1通过转录激活CASC/miR-488-3p/MMP-2的ceRNA通路介导PVAT炎症降低斑块稳定性的作用。本项目拟利用过表达/沉默技术、体外细胞模型和临床研究，阐明光谱CT在体检测ACS患者PVAT炎症状态下RUNX1转录激活CASC9/miR-488-3p/MMP-2构成的ceRNA通路调控斑块稳定性的机制，为早期识别不稳定斑块及寻找新治疗靶点提供。

冠状动脉血管外膜与血管周围脂肪组织（PVAT）共享微环境，PVAT炎症可引起冠脉斑块稳定性减低，然而PVAT导致斑块破裂引起急性冠脉综合征（ACS）的调控机制仍不明确。本项目中，我们研究探讨了RUNX1/CASC9/miR-29b-3p/MMP-2轴参与PVAT炎症降低斑块稳定性的发生发展的分子机制。通过对人脐静脉内皮细胞（HUVECs）研究，明确了RUNX1通过促进CASC9的转录， CASC9通过海绵吸附作用下调miR-29b-3p，从而减弱miR-29b-3p对靶基因MMP-2的负向调控作用，上调MMP-2的表达，进而影响冠脉斑块的稳定性导致ACS的发生发展。明确了ACS 组与对照组相比，ACS患者血清中CASC9、 miR-29b-3p 、MMP-2及PVAT光谱CT炎症指标（FAI40kev及λHU）均有显著差异，且血清学指标含量与斑块稳定性及PVAT 指标（FAI40kev及λHU）显著相关。本研究为诊断PVAT炎症状态下斑块的不稳定性提供了生物学标志物，为寻找治疗靶点、降低ACS发病率提供了新方向。