柿稀有原花青素二聚体通过脂质筏67LR抑制3T3-L1细胞分化的分子机制

我们首次发现柿果含两种稀有原花青素二聚体，且其对3T3-L1前脂肪细胞分化具有极强的抑制效果，预实验结果提示其抑制作用可能与其干扰细胞膜特性及与细胞膜67LR作用有关，但具体作用机制不详。基于柿稀有原花青素二聚体的独特结构，我们推测，脂肪细胞膜上脂质筏及伐上67LR受体可能是其作用的关键靶点。为此，本项目率先采用Western blot、RT-PCR、基因沉默等分子生物学技术及SPR、MALDI-TOF/MS、固态NMR及CSI-MS等结构分析技术，以二聚体与脂质筏和伐上受体蛋白67LR相互作用的独特视角为切入点，揭示柿稀有原花青素二聚体是如何作用于脂肪细胞膜，如何改变胞外信号的跨膜传递，抑制脂肪分化和细胞周期的关键基因PPAR-γ的表达，同时触发PPAR-γ下游信号通路的改变，抑制脂肪分化和合成的分子机制，为阐述植物多酚干预脂质代谢的分子机制提供新靶点，新理论。

We identified two unusual A-type linkage procyanidin dimers ( A-type EGCG dimer and ECG dimer) from persimmon for the first time, and found they showed outstanding inhibition effects on the differentiation of 3T3-L1 preadipocyte. Our preliminary study suggested that the inhibition might be related to their interaction with the cell membrane and 67LR, but the detailed molecular mechanisms are unknown. Based on the unique structures of the two unusaual procyanidin dimers, we infer that the lipid rafts and 67LR may be pivotal target sites of the dimers on the cell membrane of adipocyte. Therefore, this project will study the specific interactions of the dimers with the lipid rafts and membrane receptor 67LR, and further elaborate the signaling pathways and moleculae mechanisms of their interactions on interventing of adipocyte differentiation by combining use of molecular biology techniques such as Western blot,PT-PCR, gene silencing, gene cloning technology and structural analyzing techniques such as SPR, MALDI-TOF-MS, solid NMR, CIS-MS technology. The successful completion of the project will provide a new target and new theoretical basis for expounding the interventing mechanisms of plant polyphenols on lipid metabolism.