基于稳定动脉粥样硬化斑块及缺血心肌新生血管的芪参益气方防治冠心病的机制研究

Atherosclerosis ( AS ) plaque instability is the main reason leading to acute cardiovascular events, inhibition of plaque neovascularization can enhance plaque stability, but it also inhibit the compensatory angiogenesis of ischemic tissue. And instability plaque and neovascular structures of immature closely related. The myocardial ischemia area associated with plaques also has angiogenesis. Thus stable plaque neovascularization and promote neovascularization of myocardial ischemia in the same time maybe in line with the AS clinical characteristics. Qishen Yiqi formula can restrain and stabilize AS plaques and can improve the ischemic myocardial blood flow perfusion. So we research the effection of Qishen Yiqi formula on atherosclerosis basedon the stability of neovascularization. In this study ,we use swine AS and myocardial ischemia reperfusion model to detect the effection of Qishen Yiqi Decoction on plaque stability, myocardial ischemia, angiogenesis of plaque and myocardial and thier maturation. Then measure the vessel maturation correlates pathway, including VEGF, Ang1-Tie2 pathway, TGF beta pathway, bFGF / PDGF-BB / PDGFRα、β to looking for the mechanism. We also cultured aortic segment in vitro, detect the effection of Qishen Yiqi formula on angiogenesis, stabilization and regression. Then add inhibitors of the pathway above into the culture and detect the angiogenesis, it's stabilize and regression to conform the mechanism we found in vitro. We hope can provide a proof for the treatment of AS with traditional Chinese medicine.

动脉粥样硬化（AS）斑块不稳定是导致急性心血管事件的主要原因，抑制斑块内新生血管可以增强斑块稳定性，但对缺血组织的代偿性血管新生也存在抑制作用。而斑块不稳定与其新生血管结构不成熟密切相关，与斑块相关的心肌缺血区也存在血管新生，因此稳定斑块内新生血管，促进缺血心肌血管新生和成熟，更符合防治AS的临床特点。芪参益气方可抑制和稳定AS斑块并可改善缺血心肌血流灌注。故本研究从稳定新生血管入手，复制猪AS兼心肌缺血再灌注模型，检测芪参益气方对斑块稳定性、缺血心肌、斑块及心肌内血管新生及成熟的影响；并通过血管成熟相关VEGF、Ang1-Tie2通路、TGF-β通路、bFGF/PDGF-BB/PDGFR-α、β通路探讨其稳定新生血管的机制；体外培养主动脉血管段，检测该方对血管新生、稳定及消退的影响，并加入上述通路抑制剂，进一步验证芪参益气方稳定新生血管的作用。为中医药治疗AS提供科学依据。

抑制斑块内新生血管数量可以增强斑块稳定性，但对缺血组织的代偿性血管新生也存在抑制作用；斑块不稳定与其新生血管结构不成熟密切相关，含不成熟血管较多的斑块相对更不稳定。因此本项目从稳定斑块内新生血管，促进缺血心肌血管新生和成熟对芪参益气滴丸对斑块稳定性，缺血心肌的血管新生及稳定的影响及机制进行了探讨。实验复制了小型猪动脉粥样硬化兼心肌缺血模型，检测了芪参益气滴丸对模型动物血脂、心肌、冠状动脉斑块病理学变化、冠状动脉血管新生、心肌和冠状动脉拉伤段血管新生及成熟相关因子mRNA表达。结果表明，芪参益气滴丸能降低模型动物血脂、抑制斑块形成、增加斑块内胶原纤维成分降低脂质沉积、降低冠脉血管新生促进因子VEGF、KDRmRNA表达，升高新生血管稳定因子bFGF、FGFRmRNA表达，降低血管不稳定因子ANG-2、TEKmRNA表达，同时不抑制相应供血心肌血管新生相关因子mRNA表达。但在造模后2.5个月未见明显心肌缺血。因本实验小型猪在造模后2.5个月未见明显心肌缺血，为检测芪参益气滴丸对缺血心肌的保护作用及对其血管新生及稳定的影响，复制了大鼠心肌缺血模型，结果发现参益气滴丸给药3天能降低血清心肌酶含量；给药3、7、14、28天能增强左心功能，抑制左室扩张，抑制室间隔变薄；减小大鼠梗死面积；抑制左心室壁变薄，促进梗死区及边缘区血管新生及稳定。作用机制与在缺血后不同阶段对血管新生及成熟相关因子的不同趋势的调节相关。为更直观的芪参益气滴丸对血管新生及稳定的影响，体外三维培养了大鼠主动脉环，分别加入VEGF、芪参益气滴丸、VEGF+芪参益气滴丸，以不同时间点血管新生的总分支数、总长度、平均长度、最长血管长度进行了评估，结果发现芪参益气滴丸及其与VEGF合用均能促进培养血管环早期血管新生，而两者合用还能抑制新生的血管后期退化，并促进新生血管增粗及管腔样结构形成。其机制与促进血管环VEGFA、bFGFmRNA表达，降低ANG-2 mRNA表达相关。结论：芪参益气滴丸抑制斑块形成、促进斑块稳定，减小心肌缺血梗死面积，增强心功能、抑制心室扩张的功能。其作用机制与调节血管新生及成熟相关因子表达，促进缺血心肌及动脉血管新生及稳定相关。本实验为使用芪参益气滴丸治疗动脉粥样硬化及心肌缺血提供了实验依据，并初步从调节血管新生及稳定探讨了作用机制。