矢车菊素-3-O-葡萄糖苷肠道细菌代谢物原儿茶酸对巨噬细胞胆固醇逆向转运的影响及其机制研究

Although numerous studies had demonstrated that cyanidin-3-O-glucoside (C3G) possesses antiatherosclerotic property,the pharmacodynamic material basis and the underlysing mechanism remain unclear due to the very low absorption rate of C3G leading to a low plasma C3G concentration. Our recent findings revealed that protocatechuic acid (PCA), a gut microbiota of C3G, promoted cholesterol efflux from macrophage-derived foam cells arising from up-regulation of ABCA1 and ABCG1 expression, which was negatively associated with cellular miR-10b expression. Based on the above findings, we would firstly elucidate the specific role of miR-10b in the stimulatory effects of PCA on ABCA1/ABCG1 expression and cholesterol efflux capacity using macrophage-derived foam cells. Next,we would test the possibilities whether PCA promotes macrophage RCT and activates the miR-10b-ABCA1/ABCG1 pathway, as well as whether PCA is mainly responsible for the stimulatory effect of its precursor C3G on macrophage RCT using the normal gut microbiota and gut microbiota-deficient apolipoprotein-E knockout mouse models.Our study would provide theoretical foundation for the implication of anthocyanin in protecting against atherosclerosis,and identify miR-10b as a new target to promote cholesterol efflux from macrophages.

大量的研究报道矢车菊素-3-O-葡萄糖苷（C3G）具有防治动脉粥样硬化（AS）的作用，但由于C3G吸收率非常低，血浆浓度很低，其发挥抗AS作用的活性形式及其机制尚不清楚，需要深入研究。我们初步发现C3G肠道细菌代谢物原儿茶酸（PCA）可提高ABCA1和ABCG1表达，促进巨噬泡沫细胞胆固醇外流，其效应与miR-10b表达负相关。在此基础上，本项目拟采用巨噬泡沫细胞模型，明确miR-10b特异性调控ABCA1和ABCG1表达介导了PCA促进胆固醇外流作用；然后，采用正常肠道菌群及肠道菌群缺失的ApoE-/-小鼠模型，验证PCA具有促进巨噬细胞胆固醇逆向转运（RCT）的作用，其机制涉及miR-10b-ABCA1/ABCG1通路，并且明确PCA为其原形C3G发挥促进巨噬细胞RCT效应的主要活性形式。本研究将为C3G防治AS和miR-10b作为促进巨噬细胞胆固醇外流的干预靶点提供理论依据。

动脉粥样硬化（AS）性心脑血管疾病是导致全球人口死亡的最主要的疾病类型。目前临床上广泛应用的手段如他丁类等只能控制近1/3的AS患者，因此迫切需要发现防治AS的新靶点和新干预措施。本项目引入近年备受国内外广泛关注的食物活性成分花色苷和辅酶Q10，并且创新性抓住了肠道细菌与食物相互作用可影响机体健康这一国际热点，在花色苷和辅酶Q10防治AS方面取得了些许原创性成果：（1）证明了肠道细菌代谢花色苷单体矢车菊素-3-O-葡萄糖苷代谢转化成原儿茶酸发挥抗AS效应，并进一步阐明了原儿茶酸抗AS机制与通过调控巨噬细胞miR-10b促进胆固醇逆向转运有关；（2）辅酶Q缓解AS恶化的机制与调控巨噬细胞miR-378促进胆固醇逆向转运有关。这些原创性成果不仅提供了防治AS的潜在新靶点即miR-10b和miR-378，还提供了靶向这2个新靶点的干预措施即矢车菊素-3-O-葡萄糖苷/原儿茶酸和辅酶Q10。研究结果为完善理解膳食调控AS进展的机制提供了新内容，也为完善AS患者的治疗提供了具有进一步研究价值的新的膳食干预策略。