血管新生是动脉粥样硬化（AS）易损斑块形成及破裂的关键诱因。PI3K/Akt/mTOR是调控血管新生的重要通路。田螺多糖（CP）能稳定和消退斑块，但其机制不清楚。据报道，具1→3或1→6链接，且含硫酸基的多糖能抑制血管新生。课题组前期证实，CP具(1→3)-葡萄糖链接，含7.42%硫酸基，能抑制通路关键因子VEGF表达。故推测CP可能通过调控该通路抑制血管新生而稳定斑块。为验证该假说，本研究采用体内与体外实验相结合，用病理组织学、显微影像及免疫组化技术观察CP对斑块形态、组成、新生血管密度的影响；用Matrigel、Transwell小室及MTT法考察CP对内皮细胞新生血管转化的影响；用Western Blot、ELISA及qRT-PCR研究CP对斑块及内皮细胞通路信号和下游促血管新生关键因子表达的影响。从整体、细胞及分子水平探讨CP抑制斑块内血管新生的作用机制，为AS防治提供新的思路。

Angiogenesis is a key inducing factor in the formation and rupture of the atherosclerotic vulnerable plaques. PI3K/Akt/mTOR is an important pathway in intervening angiogenesis. The polysaccharide from Cipangopaludina chinensis (CP) can stabilize and decrease atherosclerotic plaques, but its mechanism is not recognized clearly at present. It has been reported that the polysaccharide, containing 1→3 or 1→6 link and sulfate radical, can inhibit angiogenesis. Our research team have confirmed that CP not only include (1→3)-glucose link and contains 7.42% of sulfate radical, but also can suppress the expression of key factor VEGF in pathways downstream. Therefore, we hypothesize that the mechanism of CP in atherosclerotic plaque stability may be inhibiting angiogenesis by adjusting PI3K/Akt/mTOR pathway. In order to verify this hypothesis, a combined method of in vivo and in vitro is used in the present research. Techniques of histopathology, microscopic imaging and immunohistochemistry are applied to observe the effect of CP on the atherosclerotic plaque area, internal composition and microvessel density. Methods of Matrigel, Transwell chamber and MTT are employed to investigate the effect of CP on transformation of endothelial cells to neovascularization. Techniques of Western Blot, qRT-PCR and ELISA are used to study the effect of CP on the expression of signal pathway and downstream key factor to promote the angiogenesis in the plaque and endothelial cells. The mechanism that CP inhibits angiogenesis in atherosclerotic plaque is discussed by regulating pathways from the whole, cell and molecular level. These studies will provide a new idea for preventing and treating atherosclerosis.