AMPK信号网络在红参酸性多糖改善2型糖尿病大鼠脂代谢紊乱中的机制研究

Lipid metabolism disturbance is the typical characteristic of type 2 diabetes mellitus (T2DM). Upon activation, AMP-activated protein kinase (AMPK) plays a key role in lipid metabolism. Consequently, it has become an attractive therapeutic target for metabolic syndromes, including T2DM. Our preliminary research showed that the acid polysaccharide of red ginseng (WGPA-S) could improve lipid metabolism disorders of type 2 diabetic rats. Meanwhile, it could activate AMPK in vivo and in vitro. The above mentioned evidences indicated that the hypoglycemic effects may be associated with the activation of the AMPK signaling pathways. But the mechanism of WGPA-S in improving lipid metabolism disorder in type 2 diabetic rats is not fully clarified. So, this work will first screen the lipid metabolism-associated genes differently expressed in AMPK pathways. Basing on the RNA-seq results, we will further develop hepatic steatosis HepG2 cell model and type 2 diabetic rat model, combining AMPK pathway inhibitor Compound C and RNA interference (RNAi), co-immunoprecipitation et al. to confirm the genetic variations associated with AMPK signal pathways induced by WGPA-S treatment. We will reflect molecular mechanism of WGPA-S in improving lipid metabolism at the animal, organ, cellular and molecular levels basing on the AMPK signaling pathway. The implementation of the program will provide the experimental basis for clinical applications of ginseng polysaccharides, it will be important and meaningful to reflect the efficacy material of Panax ginseng in prevention and cure strategy of diabetes.

脂代谢紊乱是2型糖尿病的典型特征。单磷酸腺苷活化的蛋白激酶（AMPK）在脂代谢中发挥重要作用，已成为改善脂毒性最值得关注的治疗靶点。前期工作证实红参酸性多糖（WGPA-S）可改善2型糖尿病大鼠脂代谢，并在体内、外激活AMPK，提示WGPA-S对脂代谢的调节作用可能与AMPK信号通路有关。本项目拟在此基础上构建脂肪变性细胞模型，采用RNA-seq技术筛选WGPA-S干预后AMPK信号通路中脂代谢相关的差异基因, 并验证受选基因；再以2型糖尿病大鼠为模型，从基因、蛋白、组织水平进一步考察AMPK信号网络中受选基因及相应指标的效应表现，明确WGPA-S在AMPK信号通路的作用靶点，以期望从细胞分子和整体器官水平阐释红参酸性多糖介导AMPK信号通路改善脂类代谢的分子机制。研究结果为人参多糖的临床应用提供新的实验依据，同时对于深层次揭示人参抗糖尿病的药效物质基础具有重要理论意义。

脂代谢紊乱是2型糖尿病的典型特征。单磷酸腺苷活化的蛋白激酶（AMPK）在脂代谢中发挥重要作用，已成为改善脂毒性最值得关注的治疗靶点。前期工作证实红参酸性多糖（WGPA-S）可改善2型糖尿病大鼠脂代谢，并在体内、外激活AMPK，提示WGPA-S对脂代谢的调节作用可能与AMPK信号通路有关。.本项目研究结果发现： WGPA-S 能显著降低高糖高脂联合STZ诱导的2型糖尿病大鼠TC、TG、LDL-C明显降低，并升高HDL-C水平，对2型糖尿病大鼠的脂代谢紊乱有明显改善作用。利用RNA-seq技术研究发现，WGPA-S 对脂代谢紊乱的改善作用与AMPK signaling pathway有密切关系，且主要差异基因为ACC。并利用WB及Q-PCR技术在动物水平发现WGPA-S通过激活AMPK磷酸化，进而影响其下游脂代谢关键基因ACC, SREBP-1c及FAS的表达，最终改善了2型糖尿病大鼠脂代谢紊乱。同时发现，WGPA-S能够有效抑制油酸诱导的HepG2细胞的脂质的堆积,其作用机制与激活APMK信号通路有关。本项目结果最终揭示了WGPA-S通过AMPK信号通路改善脂代谢的