GPR120基因通过调控NLRP3炎症小体激活保护脓毒症肺损伤的机制研究

The protective mechanism of GPR120 gene against sepsis-induced lung injury by regulating the activation of NLRP3 inflammasome

中文关键词: 脓毒症  肺损伤  GPR120基因  NOD样受体热蛋白结构域相关蛋白3

英文关键词: sepsis  lung injury  GPR120 gene  NOD-like receptor thermal protein domain associated protein 3(NLRP3)

中文摘要:

      目的 通过脂多糖(Lipopolysaccharide,LPS)诱导的脓毒症模型验证G蛋白偶联受体120(G-protein coupled re-ceptor120,GPR120)基因对 NOD 样受体热蛋白结构域相关蛋白 3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)炎症小体及肺损伤的影响,并探索其调控分子机制.方法 通过C57BL/6小鼠构建体内脓毒症模型,通过GPR120基因激动剂TUG891进行干预,验证GPR120基因对脓毒症小鼠肺损伤的保护作用;然后进行转录组测序,筛选差异信号通路,并在动物模型中验证NLRP3炎症小体及调控蛋白的差异表达.通过慢病毒转染构建GPR120基因过表达/低表达的Raw264.7单核巨噬细胞株,观察GPR120基因对NLRP3炎症小体的调控作用.结果 与脓毒症组相比,LPS+TUG891组小鼠肺组织中包括cAMP通路基因在内的77个基因表达显著上调,37个基因表达下降.LPS组的GPR120水平较正常对照组显著降低,同时cAMP/PKA信号通路关键蛋白CREB及PKA表达减少,NLRP3、Caspase-1及IL-1β等炎症小体激活相关蛋白水平升高(P＜0.01),予以TUG891处理后,组织内GPR120表达回升,cAMP/PKA信号通路重新被激活(P＜0.01),NLRP3炎症小体蛋白活化程度下降(P＜0.05).体外实验中,LPS诱导的脓毒症可引起细胞增殖活性下降,GPR120基因在脓毒症巨噬细胞中表达减低(P＜0.001),通过干预GPR120基因表达,证实GPR120基因可负性调控NLRP3炎症小体的活化程度及细胞炎症反应(P＜0.01).结论 脓毒症中GPR120基因的激活可通过抑制NLRP3炎症小体的活化,减轻脓毒症的炎症反应及肺损伤.

英文摘要:

      Objective To validate the effects of G-protein coupled receptor1 20(GPR120)gene on NOD-like receptor thermal protein domain associated protein 3(NLRP3)inflammasomes and lung injury by lipopolysaccharide(LPS)-induced sepsis model,and explore its regulatory molecular mechanisms.Methods C57BL/6 mice were used to construct an in vivo sepsis model,and GPR120 gene agonist TUG891 was used to verify the protective effect of GPR120 gene on lung injury in the septic mice.The transcriptome sequencing was performed to screen the differential signaling pathways,and the differential ex-pression of NLRP3 inflammasome and regulatory proteins were verified in the animal models.The Raw264.7 monocyte macro-phage cell line with GPR120 gene over/low-expressed was constructed by lentiviral transfection,and the regulatory effect of GPR120 gene on NLRP3 inflammasome was observed.Results Compared with the sepsis group,the expression of 77 genes including cAMP pathway genes in the lung tissues of mice in the LPS+TUG891 group was significantly up-regulated,and the expression of 37 genes was decreased.The level of GPR120 in the LPS group were significantly lower than that in the normal control group,and the expressions of key proteins CREB and PKA in the cAMP/PKA signaling pathway decreased,and the levels of NLRP3,Caspase-1,IL-1 β and other proteins related to inflammasome activation increased(P＜0.01).After treat-ment with TUG891,the expression of GPR120 in the tissue increased,the cAMP/PKA signaling pathway was reactivated(P＜0.01),and the activation level of NLRP3 inflammasome protein decreased(P＜0.05).In vitro experiments,LPS-induced sepsis caused a decrease in cell proliferation activity,and the expression of GPR120 gene also decreased in septic macrophages(P＜0.001).By intervening the expression of GPR120 gene,it was confirmed that GPR120 gene could negatively regulate the activation levels of NLRP3 inflammasome and cellular inflammatory response(P＜0.01).Conclusion The activation of GPR120 gene can alleviate the inflammatory response and lung injury in sepsis through inhibiting the activation of NLRP3 in-flammasome.