游离脂肪酸通过FFAR4抑制脂肪细胞KLF15的表达和葡萄糖消耗

FFA inhibits the expression of KLF15 and glucose consumption in adipocytes by FFAR4

目的通过体外诱导3T3-L1前脂肪细胞分化为成熟的脂肪细胞,探讨肥胖个体中高水平的血清游离脂肪酸(FFA)是否抑制Krüppel样因子15(KLF15)的表达,并尝试探索其可能的分子通路。方法0.8 mmol·L^-1 FFA混合液(棕榈酸∶油酸=1∶2),刺激体外培养的3T3-L1成熟脂肪细胞,同时运用阻断剂AH7614和GW1100分别阻断游离脂肪酸受体4(FFAR4)和游离脂肪酸受体1(FFAR1),qRT-PCR和Western Blot技术检测脂肪细胞FFAR4、FFAR1、KLF15、Adipolin、GLUT4和磷酸化的p38 MAPK水平,葡萄糖氧化酶法检测上清液中葡萄糖浓度。结果(1)0.8 mmol·L^-1 FFA混合液能够显著促进脂肪细胞FFAR4的表达,抑制KLF15、Adipolin、GLUT4和FFAR1的表达和脂肪细胞葡萄糖消耗(P<0.05),同时对磷酸化的p38 MAPK无影响;(2)阻断FFAR4后,0.8mM FFA混合液对脂肪细胞KLF15、Adipolin、GLUT4的表达和葡萄糖消耗的抑制作用消失(P<0.05),对磷酸化水平的p38 MAPK无影响;(3)0.8 mmol·L^-1 FFA混合液作用于脂肪细胞的同时阻断FFAR1后,脂肪细胞KLF15和GLUT4的mRNA表达水平进一步降低(P<0.01),而Adipolin的表达,磷酸化的p38 MAPK和上清液葡萄糖浓度无明显变化。结论高浓度FFA可能通过FFAR4通路抑制脂肪细胞KLF15的表达和葡萄糖消耗。

Objective To investigate whether the increased serum Free Fatty Acid(FFA)caused by obesity has an inhibitory effect on Krüppellike factor 15(KLF15)expression.Methods 0.8 mmol·L^-1 FFA mixture(palmitic acid(PA)and oleic acid(OA)mixed 1∶2)stimulated 3T3-L1 mature adipocytes cultured in vitro and block the Free Fatty Acid Receptor 4(FFAR4),Free Fatty Acid Receptor 1(FFAR1)with AH7614 and GW1100 respectively.Using qRT-PCR and Western Blot techniques to detect KLF15,Adipolin,GLUT4,FFAR4,FFAR1 mRNA and protein expression levels,the phosphorylation of p38 MAPK.Glucose oxidase method to detect glucose levels.Results(1)After treatment with 0.8 mmol·L^-1 FFA mixture for 48 hours,the expression of FFAR4 was significantly increased and the expressions of FFAR1 Adipolin,GLUT4 and the glucose assumption ability were significantly decreased(P<0.05),and phosphorylated p38 MAPK was no obviously change;(2)After treatment with 0.8 mmol·L^-1 FFA mixture and blocking FFAR4 on adipocytes,the expression level of KLF15,Adipolin,GLUT4 and glucose consumption ability of adipocytes were significantly increased and the phosphorylated p38 MAPK was not significantly different;(P<0.05).(3)After treatment with 0.8 mM FFA mixture and blocking FFAR1 on adipocytes,the expression levels of KLF15,GLUT4 were significantly decreased,while the expression level of Adipolin,the phosphorylated p38 MAPK and glucose consumption ability of Adipocytes were not significantly different(P<0.05).Conclusions High concentration of FFA may inhibits the expression of KLF15 and glucose consumption in adipocytes by FFAR4.