Ghrelin对棕榈酸诱导的THP-1巨噬细胞上TLR4/NF-κB信号通路活化的作用

摘要

Objective To investigate the effect of acylated ghrelin activating TLR4/NF-κB signaling pathway in human monocyte-derived macrophages (THP-1) induced by palmitic acid. Methods THP-1 macrophage strains were cultured by the palmitic acid in various concentrations for 12 h, treated by acylated ghrelin in different concentrations for 4 h, and then cultured with the palmitic acid 200 μmol/L for 12 h agaia The expression of TLR4 mRNA on the THP-1 macrophages was determined by quantitative real-time PCR. The levels of TLR4 protein and NF-kB p65 phosphorylation protein were measured by Western blot, and the concentrations of IL-1β and TNF-α in the cell supernatant were detected by ELISA. Results Compared with the control group, the palmitic acid increased the levels of TLR4 mRNA and protein, the NF-kB p65 phosphorylation protein, and the secretion of TNF-α and IL-1β of the THP-1 macrophages in a dose-dependent fashion (all P<0. 05). Compared to the palmitic acid 200 μmol/L group, the acylated ghrelin inhibited the levels of TLR4 mRNA (all P<0. 05), TLR4 protein, and the NF-κB p65 phosphorylation protein (all P<0. 01), and decreased the secretion of TNF-a (all P<0. 05) and IL-1β (all P<0. 01) of the THP-1 macrophages in a dose-dependent fashion. Conclusions Palmitic acid can induce the activation of TLR4/NF-κB signaling pathway in THP-1 macrophages in a dose-dependent fashion. Acylated ghrelin can inhibit the activation of TLR4/NF-κB signaling pathway in THP-1 macrophages induced by palmitic acid in a dose-dependent fashion.%目的 探讨酰基化Ghrelin对棕榈酸(PA)诱导的人源单核巨噬细胞(THP-1巨噬细胞)上TLR4-NF-κB信号通路的作用. 方法 用不同浓度的PA孵育THP-1巨噬细胞株12 h；用不同浓度的酰基化Ghrelin孵育THP-1巨噬细胞株4h后,再加入PA(200μmol/L)孵育12 h.用实时定量PCR检测THP-1巨噬细胞上TLR4 mRNA的表达水平；用Western印记检测TLR4蛋白和细胞内NF-κB p65磷酸化蛋白水平；用ELISA方法检测细胞上清液中IL-1β和TNF-α的浓度. 结果 与对照组比较,PA 呈剂量依赖性增强THP-1巨噬细胞TLR4 mRNA和蛋白的表达水平,以及NF-κB p65磷酸化蛋白水平和分泌TNF-α、IL-1β的能力(P均＜0.05).与PA(200 μmol/L)组比较,酰基化Ghrelin呈剂量依赖性抑制THP-1巨噬细胞TLR4 mRNA (P均＜0.05)、TLR4蛋白和NF-κB p65磷酸化蛋白的水平(P均＜0.01),以及降低THP-1巨噬细胞分泌TNF-α水平(P均＜0.05)和IL-1β的水平(P均＜0.01). 结论PA可剂量依赖性诱导THP-1巨噬细胞TLR4/NF-κB信号通路的活化；酰基化Ghrelin可剂量依赖性抑制PA诱导的THP-1巨噬细胞TLR4/NF-κB信号通路的活化.