NADPH氧化酶2经TLRs/NLRP3/IL-1β信号通路调控胰岛炎症微环境导致的β-细胞炎性损伤的作用及机制研究

Inflammation-induced β-cells damage is the most important pathological change in the islet inflammation microenvironment of T2DM. NLRP3 and IL-1β play an pivotal role in this process. NOX2 is a new regulatory factor in function of β-cells, however, the role of NOX2 in β-cells inflammatory damage has not been reported. We found for the first time that down-regulation of NOX2 in pancreas of db/db mice resulted in decreased IL-1β production, improved β-cells function and blood glucose. Recently, TLRs is considered to be an important regulator of NLRP3 and IL-1β inflammatory pathway. Our previous study showed that NOX2 might regulate TLRs through lipid rafts. Therefore, we put forward the hypothesis that NOX2 may regulate the NLRP3 and IL-1β inflammatory pathway through TLRs, and then regulate the inflammatory microenvironment of pancreatic islets and affect the function of β-cells. To test this hypothesis, we explore the role of NOX2 in the inflammatory injury process of β-cells from the molecular, cellular, organizations and the overall level by using cellular and animal models; we investigate the mechanism of TLRs regulated by NOX2 and the role of NOX2 involved in the regulation of NLRP3 and IL-1β pathway activation. This project will reveal the molecular mechanism of islet inflammatory microenvironment in β-cell dysfunction from the new point of view and provide new perspective for T2DM prevention.

β-细胞炎性损伤是T2DM胰岛炎症微环境重要的病理变化。NLRP3/IL-1β是炎性损伤中重要调控通路。NOX2是β-细胞功能中新的调控因子，但它在β-细胞炎性损伤中的作用未见报道。我们首次发现：在db/db小鼠胰腺中下调NOX2表达，IL-1β产生减少，改善β-细胞功能和小鼠血糖水平。研究显示TLRs是NLRP3/IL-1β通路的正调节因子。在前期研究中，我们发现NOX2可能通过脂筏募集调控TLRs。因此我们提出假说：NOX2可能通过TLRs调控NLRP3/IL-1β炎症通路，进而调节胰岛炎症微环境影响胰岛β-细胞功能。为验证该假说，我们应用细胞模型和小鼠模型，从分子、细胞、组织及整体水平明确NOX2在β-细胞炎性损伤中的作用，阐明NOX2通过TLRs调控NLRP3/IL-1β通路参与T2DM的作用机制。本项目的研究将为胰岛炎症微环境的分子机制奠定基础，为T2DM的防治提供新思路。

本项目基于我们研究工作中发现的重要实验现象，结合国内外关于T2DM中胰岛慢性炎症学说进展以及NOX2最新研究的提示，凝练出科学问题并提出了自己的假说。为了验证上述假说，我们应用小鼠胰岛β-细胞系NIT-1/MIN-6、小鼠原代骨髓来源巨噬细胞BMDM/小鼠腹腔来源巨噬细胞系RAW264.7、以及基因缺陷（db/db）/高脂饮食诱导的T2DM小鼠模型，采用real time PCR、Western blot、RNA干扰等手段，从分子、细胞、组织及整体水平明确了NOX2对胰岛慢性炎症反应过程的调控作用；以TLRs为切入点，确定了NOX2对TLRs的调节机制，阐明了其激活NLRP3和IL-1β炎症信号通路影响胰岛β-细胞功能进而调控T2DM进程的分子机制。综上所述，本研究从NOX2这一新视点探讨了T2DM进程中胰岛炎症微环境引发β-细胞炎性损伤的分子机制，为揭示糖脂毒性诱导胰岛炎症微环境的发生机制奠定基础，为2型糖尿病的防治提供抗炎、抗免疫治疗的新靶点和新思路。