肝细胞NLRP3通过PDEs/cAMP/PKA途径调控胰高血糖素驱动的肝糖异生作用及分子机制

胰高血糖素可促进肝糖异生，其与胰岛素共同维持机体血糖稳态。胰高血糖素失调与2型糖尿病的发生发展密切相关，但其信号通路的精细调控机制仍不甚明了，制约着该类激素在糖尿病防治中的作用。申请人前期发现肥胖小鼠肝脏NLRP3高表达；体外筛选出沉默NLRP3可显著改善肝糖异生现象，亦可维持肝脏PDEs活性、抑制cAMP堆积；动物预实验亦得出与体外结论一致。我们推测：NLRP3通过胰高血糖素/PDEs/cAMP/PKA途径调控肝糖异生。基于此，拟用loxp-cre体系制备的肝脏特异性Nlrp3敲除小鼠模型，开展以下内容：(1)探讨NLRP3对肝糖异生的调控作用；(2)解析NLRP3调控肝糖异生的潜在分子机制；(3)绘制NLRP3调控肝糖异生网络和探究MCC950对肝糖异生的影响。本研究的实施将阐明NLRP3在肝糖异生中的作用及机制，有望为肝糖异生提供新科学认识，并为发现潜在的降糖药物提供新靶点。

Glucagon can promote hepatic gluconeogenesis and maintain whole-body glucose homeostasis with insulin. Glucagon dysfunction is tightly associated with the initiation and development of type 2 diabetes, but the precise and regulatory mechanism of its signaling pathway is still unclear, limiting the role of the hormone in the prevention and treatment of diabetes mellitus. Applicant previously found that the expression of liver NLRP3 was high in obese mice; Screening that NLRP3 knockdown can significantly improve hepatic gluconeogenesis in vitro, which also preseved liver PDEs activity and inhibited cAMP accumulation; the same conclusion was drawn from animal preliminary experiments. We speculate that hepatocyte NLRP3 regulates glucagon-driven hepatic gluconeogenesis by PDEs/cAMP/PKA pathway. Based upon these evidences, the model of liver specific nlrp3 knockout mouse is prepared by loxp-cre system. The major parts include: (1) to elucidate the detail effects of NLRP3 on hepatic gluconeogenesis; (2) to explore its potential signaling molecular pathways for hepatic gluconeogenesis; (3) to mapping the networks of regulation of hepatic gluconeogenesis by NLRP3 and explore the effects of MCC950 on hepatic gluconeogenesis. The implementation of this study will elucidate the role and mechanism of NLRP3 in the regulation of hepatic gluconeogenesis, which is expected to provide a new scientific understanding of hepatic gluconeogenesis and new target for the discovery of potential antidiabetic drugs.