C17∶0激活GPR40受体的作用及信号转导分子机制研究

Study on the effect of C17∶0 activating GPR40 receptor and the molecular mechanism of signal transduction

目的研究长链脂肪酸C17∶0对GPR40受体的激活作用,并探讨其介导的信号转导分子机制。方法在体外培养HEK293T细胞的基础上,免疫荧光结合共聚焦显微镜检测受体膜定位和内吞情况;通过多功能酶标仪检测Ca^(2+)流的强弱;Western Blot检测ERK1/2的磷酸化水平。结果免疫荧光结果显示:C17∶0可通过招募β-arrestin 2介导GPR40内吞;胞内Ca^(2+)动员检测结果证实:长链脂肪酸C17∶0可作用于GPR40引起胞内Ca^(2+)浓度升高;Western Blot结果显示:C17∶0可作用于GPR40诱导ERK1/2磷酸化。结论C17∶0是GPR40的内源性配体,通过激活Gaq和Gai/o蛋白介导的信号通路,引起胞内Ca^(2+)动员及ERK1/2的磷酸化。

Objective To study the activation of long chain fatty acid C17∶0 on GPR40 receptor and explore its molecular mechanism of signal transduction.Methods On the basis of HEK293T cells cultured in vitro,the localization and endocytosis of receptor membrane were detected by immunofluorescence combined with confocal microscopy;The strength of Ca~(2+)flow was detected by a multifunctional microplate reader;The phosphorylation level of ERK1/2 was detected by Western Blot.Results The results of immunofluorescence showed that GPR40 endocytosis could be mediated by recruitment of β-arrestin2 at C17∶0;The results of intracellular Ca~(2+) mobilization test confirmed that long chain fatty acid C17∶0 could act on GPR40 to increase intracellular Ca~(2+) concentration;Western Blot results showed that C17∶0 could act on GPR40 to induce ERK1/2 phosphorylation.Conclusion C17∶0 is an endogenous ligand of GPR40,which can cause intracellular Ca~(2+) mobilization and ERK1/2 phosphorylation by activating Gaq and Gai/o protein mediated signal pathways.