GPR120对脂多糖诱导的胰岛β细胞炎症损伤及TLR4/MyD88/NF-κB p65信号通路的影响

Effects of GPR120 on lipopolysaccharide induced inflammatory injury of islet beta cells and TLR4/MyD88/NF-κB p65 signaling pathway

目的:探讨过表达G蛋白偶联受体120(GPR120)对脂多糖(LPS)诱导的胰岛β细胞炎症损伤及Toll样受体4(TLR4)/髓样分化因子(MyD88)/核转录因子-κB(NF-κB)信号通路的影响。方法:将MIN6细胞分为control组(细胞用无血清培养液进行培养)、LPS组(细胞用含10μg·ml^(-1) LPS的培养液进行培养)、LPS+control组(感染阴性对照慢病毒的细胞用10μg·ml^(-1) LPS培养液处理)、LPS+GPR120组(感染pcDNA3.1-GPR120慢病毒的细胞用10μg·ml^(-1) LPS培养液处理)4组。CCK-8法检测细胞增殖;Annexin-V-FITC/PI流式细胞术检测细胞凋亡;ELISA检测IL-6、IL-1β和TNF-α水平;蛋白质印迹法检测GPR120、TLR4、MyD88、NF-κB p65蛋白的表达。结果:LPS组GPR120蛋白相对表达量明显低于control组(P<0.05);LPS+GPR120组GPR120蛋白相对表达量明显高于LPS+control组(P<0.05)。LPS组细胞增殖活力明显低于control组(P<0.001);LPS+GPR120组细胞增殖活力明显高于LPS+control组(P<0.001)。LPS组细胞凋亡率明显高于control组(P<0.001);LPS+GPR120组细胞凋亡率明显低于LPS+control组(P<0.001)。LPS组细胞上清液中IL-6、IL-1β和TNF-α水平均高于control组(均P<0.001);LPS+GPR120组IL-6、IL-1β和TNF-α水平均低于LPS+control组(均P<0.001)。LPS组细胞TLR4、MyD88、NF-κB p65蛋白相对表达量均高于control组(均P<0.001),LPS+GPR120组TLR4、MyD88、NF-κB p65相对表达量均低于LPS+control组(均P<0.001)。结论:GPR120可能通过抑制TLR4/MyD88/NF-κB p65信号通路在LPS诱导的胰岛β细胞炎症损伤中发挥保护作用。

Objective:To investigate the effects of overexpression of G-protein coupled receptor 120(GPR120)on lipopolysaccharide(LPS)induced inflammation of islet beta cells and the Toll like receptor 4(TLR4)/myeloid differentiation factor(MyD88)/nuclear factor-κB(NF-κB)signaling pathway.Methods:MIN6 cells were divided into four groups:control group(cells were cultured in serum-free medium),LPS group(cells were cultured in medium containing 10μg·ml^(-1) LPS),LPS+control group(cells infected with negative control lentivirus were treated with 10μg·ml^(-1) LPS medium),and LPS+GPR120 group(cells infected with pcDNA3.1-GPR120 lentivirus were treated with 10μg·ml^(-1) LPS medium).CCK-8 method was used to detect cell proliferation;Annexin-V-FITC/PI flow cytometry was used to detect apoptosis;ELISA was used to detect IL-6,IL-1βand TNF-α;Western blot was used to detect the expression of GPR120,TLR4,MyD88 and NF-κB p65.Results:The relative expression of GPR120 protein in LPS group was significantly lower than that in control group(P<0.05);the relative expression of GPR120 protein in LPS+GPR120 group was significantly higher than that in LPS+control group(P<0.05).The cell proliferation activity of LPS group was significantly lower than that of control group(P<0.001);the cell proliferation activity of LPS+GPR120 group was significantly higher than that of LPS+control group(P<0.001).The apoptosis rate of LPS group was significantly higher than that of control group(P<0.001);the apoptosis rate of LPS+GPR120 group was significantly lower than that of LPS+control group(P<0.001).The levels of IL-6,IL-1βand TNF-αin the supernatant of LPS group were higher than those of control group(all P<0.001);the levels of IL-6,IL-1βand TNF-αin LPS+GPR120 group were lower than those in LPS+control group(all P<0.001).The relative expression levels of TLR4,MyD88 and NF-κB p65 in LPS group were higher than those in control group(all P<0.001).The relative expression levels of TLR4,MyD88 and NF-κB p65 in LPS+GPR120 group were lower than those in LPS+control group(all P<0.001).Conclusion:GPR120 may play a protective role in LPS induced inflammatory injury of islet beta cells by inhibiting TLR4/MyD88/NF-κB p65 signaling pathway.