Quantification of PPAR-γ protein in monocyte/macrophages from healthy smokers and non-smokers:: A possible direct effect of nicotine
Quantification of PPAR-γ protein in monocyte/macrophages from healthy smokers and non-smokers:: A possible direct effect of nicotine
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DOI：
10.1016/j.lfs.2007.07.017
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发表时间：
2007-08-23
期刊：
影响因子：
6.1
通讯作者：
Brunelleschi, Sandra
中科院分区：
文献类型：
--
作者：
Amoruso, Angela;Bardelli, Claudio;Brunelleschi, Sandra
以往的研究表明，脂肪细胞分化的关键调节因子--过氧化物酶体增殖物激活受体-γ(PPAR-γ)在多种细胞中都有表达，包括单核/巨噬细胞系的细胞。本研究旨在对健康吸烟者和非吸烟者分离的单核细胞和单核细胞来源的巨噬细胞(MDM)中PPAR-γ的组成性表达和配体诱导的表达进行定量，并评估尼古丁可能的直接作用。用Western印迹法检测PPAR-γ蛋白的表达，并计算PPAR-γ与β-肌动蛋白表达的比值进行定量。用酶联免疫分析试剂盒检测细胞因子的释放。在人单核细胞中检测到组成性的PPAR-γ蛋白，其表达随着分化为MDM而上调。内源性配体15-脱氧-三角洲(12.14)-前列腺素J(2)和合成激动剂环格列酮促进PPAR-γ的表达，前者在低微摩尔浓度时也有效。两种激动剂均显著抑制促炎细胞因子(如肿瘤坏死因子-α、白介素6)的基础分泌，而西格列酮的作用更强。与健康非吸烟者相比，健康吸烟者的单核细胞和MDM的PPAR-γ结构性表达显著增强(分别是4倍和2.5倍)。然而，在健康吸烟者和非吸烟者中，配体诱导的PPAR-γ表达和细胞因子分泌的抑制是相似的。尼古丁呈剂量依赖性地促进PPAR-γ的表达，在10MU时达到最大值，并抑制促炎细胞因子的释放；这些作用可被α-银环蛇毒素逆转。尼古丁和PPAR-γ激动剂没有协同作用。总之，来自健康吸烟者的单核细胞和MDM呈现结构性增强的PPAR-γ表达；这种效应在某种程度上是由尼古丁在体外复制的。(C)2007 Elsevier Inc.保留所有权利。
Previous observations demonstrated that Peroxisome Proliferator-Activated Receptor-gamma (PPAR-gamma), a key regulator of adipocyte differentiation, is expressed in a large variety of cells, including cells of the monocyte/macrophage lineage. This study was aimed to quantify both the constitutive and ligand-induced PPAR-gamma expression in monocytes and monocyte-derived macrophages (MDM) isolated from healthy smokers and non-smokers, and to evaluate the possible direct effect of nicotine. PPAR-gamma protein was detected by Western blot and quantification was performed by calculating the ratio between PPAR-gamma and beta-actin protein expression. Cytokine release was measured with enzyme-linked immunoassay kits. Constitutive PPAR-gamma protein was detected in human monocytes and its expression was up-regulated along with differentiation to MDM. The endogenous ligand 15-deoxy-delta(12.14)-prostaglandin J(2) and the synthetic agonist ciglitazone enhanced PPAR-gamma expression, the former being effective also at low micromolar concentrations. Both agonists significantly inhibited the basal secretion of pro-inflammatory cytokines (e.g., TNF-alpha, IL-6), ciglitazone being more potent. Monocytes and MDM from healthy smokers presented a significantly enhanced (4-fold and 2.5-fold, respectively) constitutive PPAR-gamma expression, as compared to those from healthy non-smokers. However, ligand-induced PPAR-gamma expression and inhibition of cytokine secretion were similar in healthy smokers and non-smokers. Nicotine dose-dependently enhanced PPAR-gamma expression with a maximum at 10 mu M, and inhibited release of pro-inflammatory cytokines; these effects were reversed by alpha-bungarotoxin. Nicotine and PPAR-gamma agonists did not exert synergistic effects. In conclusion, monocytes and MDM from healthy smokers present a constitutively enhanced PPAR-gamma expression; this effect is reproduced, to some extent, by nicotine in vitro. (C) 2007 Elsevier Inc. All rights reserved.