替米沙坦通过激活PPARγ而下调NF-κB通路抑制脂多糖诱导的单核细胞THP-1炎症反应

Telmisartan Can Activate Peroxisome Proliferator-activated Receptor Gamma to Down-regulate the Nuclear Factor-Kappa B Pathway to Inhibit Monocytes THP-1 Inflammatory Response Induced by Lipopolysaccharide

目的探讨替米沙坦(Telm)对脂多糖(LPS)诱导的人THP-1巨噬细胞炎症因子释放的影响及机制。方法体外培养人THP-1单核细胞随机分为对照组、脂多糖组和替米沙坦组(LPS+Telm)。替米沙坦组细胞予替米沙坦(10μmol/L)预孵育2 h后与脂多糖组均加入脂多糖刺激24 h。应用Western blot检测各组细胞过氧化体增殖物激活型受体γ(PPARγ)、磷酸化过氧化体增殖物激活型受体γ(p-PPARγ)、IκBα、磷酸化IκBα(p-IκBα)、核因子κB(NF-κB)、磷酸化核因子κB(p-NF-κB)的蛋白表达,ELISA法检测各组细胞培养上清中单核细胞趋化蛋白1(MCP-1)、肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的表达水平,应用实时定量PCR(RT-PCR)检测各组细胞MCP-1、TNF-α和IL-6的mRNA表达水平。结果 Western blot检测发现,与对照组相比,脂多糖组p-PPARγ、pNF-κB和p-IκBα蛋白表达水平明显升高(P<0.05),IκBα表达明显下降(P<0.05),PPARγ和NF-κB表达水平无显著差异(P>0.05);RT-PCR和ELISA检测发现,与对照组相比,脂多糖组MCP-1、TNF-α和IL-6蛋白水平和mRNA表达水平均明显增高(P<0.05)。与脂多糖组相比,替米沙坦组p-NF-κB和p-IκBα蛋白水平表达明显下降,MCP-1、TNF-α及IL-6分泌水平和mRNA水平也均明显降低,p-PPARγ和IκBα蛋白表达水平明显增加(P<0.05),但是NF-κB和PPARγ表达水平依然无显著差异(P>0.05)。结论替米沙坦预处理可通过激活PPARγ而下调NF-κB活化从而抑制脂多糖诱导单核细胞THP-1产生炎症反应。

Background and Aim Telmisartan （Telm）, one of peroxisome proliferator-activated receptor gam- ma （PPARγ） agonist. To investigate the effects and potential mechanisms of Telmisartan on pro-inflammatory eytokine release and expression from lipopolysaccharide （LPS） -induced THP-1 mononuciear ceils. Methods The human THP- 1 mononuclear cells were cultured and randomly divided into 3 groups： control group, LPS group, and Telm group. After Telm group pre-incubated with Telm（ 10 μmol/L）for 2 h, Telm group and LPS group were both stimulated with LPS for 24 h. The expression of PPARγ, p-PPARγ, inhibitor of nuclear factor-kappa B （IKBot）, p-IκBα, NF-κB and p-NF-KB in total protein of cell extract of each group were measured by Western blot. The level of monocyte chemotactic protein 1 （MCP-1）, tumor necrosis factor alpha （TNF-α） and interleukin-6 （IL-6） in supernatant and cell of each group were measured by ELISA and RT-PCR. Results Compared with the control group, the expression of p-PPARγ, p-NF-κB, p-1κBα, MCP-1, TNF-α and IL-6 in the LPS group were significantly increased accompanied with the decrease of IκBα（P 〈 0. 05 ）, but there was no difference on the expression of NF-KB and PPAR/between the two groups （P 〉 0. 05）. Com- pared with the LPS group, the expression of p-NF-KB, p-IκBα, MCP-1, TNF-α and IL-6 in the Telm group were signifi- cantly decreased accompanied with the increase of IKBα and p-PPAR（ P 〈 0. 05）. There was still no difference on theexpression of NF-κB and PPAR/between the two groups （P 〉 0. 05）. Conclusion Telmisartan pretreatment can in- hibit inflammation induced by LPS-stimulating THP-1 mononuclear cells, and the mechanisms may be related to preventing NF-κB activation through further PPARγ activation.