cAMP信号通路介导的FGF21对T2DM糖脂代谢的调控机制研究

The incidence of type 2 diabetes mellitus (T2DM) is increasing year by year, whereas, so far the clinical drugs not only cannot meet the regulating mechanism of circadian rhythms of the body metabolism, but have major side effects. FGF21, as a new therapeutic target, may be a new drug for the treatment of T2DM and metabolic syndrome because of its unique biological functions and pharmacological properties. Our research group utilized the hFGF21 to take gene therapy on the T2DM animal models and we have achieved a certain therapeutic effects in clinical index and pathological protection. At the same time, the phenomenon is found that cAMP signal pathway is activated in hFGF21-overpressed liver cells with the upregulation of some genes of glucolipid metabolism, so we infer that cAMP signal pathway possibly mediate the function of FGF21 on glucolipid metabolism. Our project plan to detect the cAMP signal pathway in vitro and take dynamic study on the gene therapy of hFGF21 in T2DM rhesus monkey model, and then to utilize gene chip technology to analyze the dynamic relation between clinical index and cAMP signal pathway in the whole process including prior, under and post treatment. Next, we would screen out the related genes in glucose and lipid metabolism and signal pathways regulated with cAMP, and then to take the blocking test of the scanned signal pathway for elucidating the molecular mechanism in T2DM rhesus model. The study provides a more complete molecular and theoretical basis for the development and application of new drug, hFGF21 and a theoretical clue for drug research on the method of signal molecular in the process of signal transduction as drug targets, which would have important reference value and practical significance for T2DM research.

2型糖尿病（T2DM）呈逐年增加趋势，临床药物不能满足机体代谢的生理节律性调节机制，副作用大。FGF21是新发现的治疗靶点，其降糖降脂等独特的药理特性可能成为治疗T2DM的新药，但其对T2DM糖脂代谢调控的系统分子机制还未被阐明。我们运用hFGF21对T2DM动物模型进行基因治疗在临床指标和病理保护上已取得一定的治疗效果，在hFGF21过表达肝细胞中发现cAMP信号通路被激活，部分糖脂代谢基因表达上调，我们推断可能是cAMP信号通路介导了FGF21对糖脂代谢调控功能的发挥。本项目拟在细胞水平和FGF21基因治疗T2DM恒河猴模型中用芯片分析cAMP相关信号通路和糖脂代谢基因以及治疗前/中/后临床指标与cAMP信号通路的动态联系，对信号通路进行阻断验证，明确信号通路和基因的联系，初步阐明其分子机制。为hFGF21新药开发提供完整的分子基础，为以信号转导为药靶的新药研究提供更多的理论线索。

背景：2 型糖尿病是一种代谢紊乱疾病，中国已有9700万的糖尿病患者，其中T2DM患者约占了95%，并且呈逐年增加趋势。目前还没有确切有效的治疗方法可治愈该病，继续寻找安全有效的治疗药物和方法仍然是当今急待解决的问题。FGF21 是一种特异性作用于肝脏、胰岛和脂肪组织的新型糖脂代谢调控因子，具有降低血脂、血糖、改善胰岛素抵抗和胰岛β细胞功能的作用，在机体的糖脂代谢中具有重要作用，成为了治疗 T2DM 和代谢综合征的一个很有希望的治疗靶点，但是它系统的治疗作用机制和对糖脂代谢的综合调控与信号转导通路还不完全清楚，还有待进一步揭示和阐明。.研究内容：（1）hFGF21基因过表达/敲除细胞株的建立和测序分析；（2）细胞信号转到通路的信号分子监测和验证；（3）慢病毒介导hFGF21基因治疗T2DM动物模型的临床监测和cAMP相关信号转导通路分子的检测。.重要结果：（1）建立了hFGF21基因稳定过表的HL7702细胞株和hFGF21基因稳定敲除的HL7702细胞株；（2）hFGF21对T2DM动物模型进行肝脏靶向基因治疗可长期控制和恢复空腹血糖，改善糖脂代谢相关临床指标和组织病理状况，可逆转肝脏脂肪变性和提高肝/肌糖原的合成能力；（3）hFGF21是通过第二信使cAMP信号转导通路介导抑制了NFkB的表达和激活了PI3K/AKT通路，在改善炎症的同时很大程度上恢复了机体的糖脂代谢功能。.关键数据：（1）hFGF21基因敲除/过表达的HL7702细胞株的转录组分析结果表明，hFGF21是通过激活PI3K/AKT信号通路参与糖代谢过程；（2）hFGF21可提高肝脏PDX1的表达保护胰岛细胞和促进胰岛素分泌；（3）hFGF21肝脏靶向基因治疗可能通过上调GLP-1R的表达，增强了GLP-1的生物学活性，激活了cAMP的信号转到，同时介导了NFkB信号通路的抑制和PI3K/AKT信号通路的激活，从而起到治疗T2DM的作用。.科学意义：初步阐明了hFGF21通过改善糖脂代谢而治疗T2DM的一个分子机制，发现了GLP-1R可能是FGF21改善糖脂代谢的一个靶基因，可为相关新药研发提供一定的理论线索。