应用OCT-IVUS双模成像技术研究放射治疗对动脉粥样硬化斑块稳定性的作用及机制

肿瘤合并冠心病患者日益增多，其中胸部恶性肿瘤合并冠心病患者经放射治疗后心脏不良事件显著增加的临床现象引发关注。目前放射治疗导致冠脉斑块不稳定的机制尚不清楚，且缺乏在体客观精准影像学评估手段。课题组原创OCT-IVUS双模同步成像技术实现在体斑块特征和结构的精确识别，前期应用该技术发现放射治疗可诱发冠心病患者冠脉斑块不稳定，斑块内巨噬细胞密度增加，分子生物学检测发现METTL3及Irgm1表达升高。因此提出放射治疗通过m6A甲基化修饰Irgm1调控巨噬细胞功能从而影响冠状动脉斑块稳定性。课题组利用射线照射的兔颈动脉斑块模型，应用OCT-IVUS双模成像技术精准评估射线照射介导斑块特征改变及动态演变，深入解析射线照射介导斑块改变的发生机制，阐明其通过m6A甲基化修饰Irgm1调控巨噬细胞功能影响斑块稳定性，为放射治疗介导的斑块不稳定提供防治新靶点，为临床早期精确诊断和及时干预提供依据。

There are more and more patients with tumor and coronary heart disease, among them, the clinical phenomenon of the significant increase of cardiac adverse events in patients with chest tumor and coronary heart disease after radiation therapy has aroused concern. At present, the mechanism of coronary plaque instability caused by radiation therapy is not clear, and there is a lack of objective and accurate imaging evaluation methods in vivo. The original new OCT-IVUS dual-mode synchronal imaging technology of our research group can realize the accurate recognition of the characteristics and structure of the plaque in vivo. In the early stage, with the application of this technology we found that radiation therapy can induce the coronary plaque instability, increase the density of macrophages in the plaque, and then increase the expression of METTL3 and Irgm1 through the molecular biological detection. Therefore, we propose that radiation therapy can regulate the function of macrophages through m6A methylated Irgm1, thereby affecting the stability of coronary artery plaques. The rabbit carotid atherosclerosis model of radiation therapy and OCT-IVUS dual-mode synchronal imaging technology will be used in our group to accurately evaluate the characteristics and dynamic evolution of radiation-induced plaque, deeply analyze the mechanism of radiation-induced changes in coronary plaque, and clarify the effect of radiation therapy on the stability of plaque by m6A methylation modified Irgm1, in order to provide a basis for early clinical accurate diagnosis and timely intervention.