转录因子KLF16调控肝脏糖脂代谢的机制研究

Abnormal regulation of hepatic glucose and lipid metabolism aggravates the pathogenesis of diabetes mellitus, while its mechanism remains incompletely unknown. Krüppel-like factors (KLFs) have been reported to be tightly associated with the development of diabetes and its complications. Our preliminary data demonstrated that hepatic expression of KLF16 in diabetic mice was significantly increased. Meanwhile, the hepatic KLF16 rapidly responded to the nutrition status and insulin treatment. Overexpression of KLF16 also leads to the increased glucose output and lipid accumulation in primary hepatocytes, suggesting that KLF16 may be not only a critical diagnostic marker of diabetes and its complications, but also a key node to regulate insulin sensitivity in the liver. Based on these data, we intend to investigate the detailed function and molecular mechanism by which KLF16 regulates hepatic glucose and lipid metabolism from the abilities to sense nutrition, to respond hormones, to induce inflammation and regulate transcription. Combining the transcriptome analysis, luciferase reporter gene assay and chromatin immunoprecipitation (ChIP), we will explore the key mediator of KLF16 and further demonstrate the regulatory manners. After that, we will elucidate the effectiveness of KLF16 which serves as a regulator to remodel glucose homeostasis through intervening the expression of KLF16 in diabetic mice using adenovirus expression system. Our study will reveal the novel mechanism to develop diabetes, and provide potential strategies for the research and treatment of diabetes and its complications.

肝脏糖脂代谢异常是糖尿病重要的致病因素，但其具体病理机制尚不清楚。研究显示，转录因子KLFs家族在糖尿病及其并发症中发挥重要功能。申请者前期研究发现，KLF16在糖尿病小鼠肝脏中表达上调，并对营养状态改变和胰岛素处理应答迅速。KLF16过表达显著上调肝脏原代细胞中葡萄糖输出量和脂质沉积。提示KLF16可能是诊断糖尿病及其并发症的重要标志，同时也可能是调控肝脏胰岛素敏感性的关键节点。基于此，申请者拟从感知营养、应答激素、诱发炎症和调控转录等角度研究KLF16调节肝脏糖脂代谢的功能及机制。利用转录组学分析结合报告基因实验、染色质免疫共沉淀等方法，鉴定介导KLF16生物功能的关键分子，对相关分子机制进行深入探索，最后在糖尿病动物模型中干预KLF16的表达，研究其做为重塑血糖稳态调控的分子的有效性。本项目将揭示糖尿病发生的新机制，同时为糖尿病治疗新策略的研究奠定基础。

肝脏糖脂代谢异常是诱发糖尿病、非酒精性脂肪肝等代谢性疾病的关键因素。其中，糖异生失调和脂肪酸氧化分解异常是其主要特征，但具体的病理机制尚未完全解析。本项目聚焦于转录因子KLF16调控肝脏糖脂代谢的功能及机制。首先发现并证实KLF16蛋白在糖脂代谢紊乱的动物模型及临床样本中表达降低。随后通过构建肝脏特异性敲除小鼠及病毒介导过表达的模式动物和细胞的方法证实KLF16可通过改善肝脏脂肪酸氧化进程进而维持机体糖脂代谢稳态。最后通过转录组学、ChIP等实验方法鉴定发现KLF16靶向结合PPARα启动子区域进而激活脂肪酸氧化分解关键基因的作用机制，并在细胞和动物水平对该作用通路加以验证。总之，本研究通过细胞、动物水平研究发现了KLF16-PPARα作用通路在维持机体糖脂代谢稳态方面的重要作用，揭示了糖尿病发生的新机制，同时为糖尿病治疗新策略的研究奠定基础。