蛋白激酶C-ε与Toll样受体4协同调节人巨噬细胞中抵抗素介导的炎症反应。
PKC-epsilon and TLR4 synergistically regulate resistin-mediated inflammation in human macrophages.
作者信息
Zuniga Mary C, Raghuraman Gayatri, Hitchner Elizabeth, Weyand Cornelia, Robinson William, Zhou Wei
机构信息
Department of Vascular Surgery, VA Palo Alto Health Care System, Palo Alto, CA, USA.
Department of Vascular Surgery, VA Palo Alto Health Care System, Palo Alto, CA, USA; Division of Immunology and Rheumatology, Department of Medicine, Stanford University, Stanford, CA, USA.
出版信息
Atherosclerosis. 2017 Apr;259:51-59. doi: 10.1016/j.atherosclerosis.2017.02.021. Epub 2017 Feb 24.
BACKGROUND AND AIMS
Resistin has been associated with atherosclerotic inflammation and cardiovascular complications. We and others have previously shown that PKC-epsilon (PKCε) is involved in resistin-induced smooth muscle cell (VSMC) dysfunction at a high pathological concentration. This study aimed to evaluate the role and potential pathways of resistin at a physiological concentration, in atherosclerosis-related inflammation.
METHODS
Plasma from patients with atherosclerosis was analyzed for resistin concentration. Patients were divided into tertiles based on resistin levels and cytokines were compared between tertiles. Macrophages were then treated with resistin in the presence or absence of PKCε inhibitor and/or TLR4 blocking-antibody, and their inflammatory state was evaluated with ELISA, RT-PCR, immunocytochemistry, and Western blot.
RESULTS
We observed significant associations between plasma resistin levels and TNF-α, IL-6, IL-12, MIP-1α, MIP-1β, and CD40L. Our in vitro analyses revealed that resistin activated PKCε via TLR4. This was followed by NF-kB activation and induction of a pro-inflammatory phenotype in macrophages, significantly upregulating CD40, downregulating CD206 and stimulating gene expression and secretion of the inflammatory cytokines, for which we found association in our plasma analysis. Resistin also induced persistent TRAM and CD40L upregulation up to 36 h after resistin treatment. PKCε and TLR4 inhibitors suppressed gene expression to levels similar to control, especially when used in combination.
CONCLUSIONS
Resistin, at a physiological concentration, exacerbates the inflammatory response of macrophages. PKCε is a key upstream mediator in resistin-induced inflammation that may interact synergistically with TLR4 to promote NF-kB activation, while TRAM is an important signal. PKCε and TRAM may represent novel molecular targets for resistin-associated chronic atherosclerotic inflammation.
背景与目的
抵抗素与动脉粥样硬化炎症及心血管并发症相关。我们和其他研究人员之前已经表明，在高病理浓度下，蛋白激酶C-ε（PKCε）参与抵抗素诱导的平滑肌细胞（VSMC）功能障碍。本研究旨在评估生理浓度的抵抗素在动脉粥样硬化相关炎症中的作用及潜在途径。
方法
分析动脉粥样硬化患者血浆中的抵抗素浓度。根据抵抗素水平将患者分为三分位数，并比较三分位数之间的细胞因子。然后在有或没有PKCε抑制剂和/或TLR4阻断抗体的情况下，用抵抗素处理巨噬细胞，并用酶联免疫吸附测定（ELISA）、逆转录-聚合酶链反应（RT-PCR）、免疫细胞化学和蛋白质印迹法评估其炎症状态。
结果
我们观察到血浆抵抗素水平与肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、白细胞介素-12（IL-12）、巨噬细胞炎性蛋白-1α（MIP-1α）、巨噬细胞炎性蛋白-1β（MIP-1β）和CD40配体（CD40L）之间存在显著关联。我们的体外分析表明，抵抗素通过TLR4激活PKCε。随后是核因子-κB（NF-κB）激活，并在巨噬细胞中诱导促炎表型，显著上调CD40，下调CD206，并刺激炎性细胞因子的基因表达和分泌，我们在血浆分析中发现了它们之间的关联。抵抗素还在抵抗素处理后长达36小时诱导TRAM和CD40L持续上调。PKCε和TLR4抑制剂将基因表达抑制到与对照相似的水平，尤其是联合使用时。
结论
生理浓度的抵抗素会加剧巨噬细胞的炎症反应。PKCε是抵抗素诱导炎症中的关键上游介质，可能与TLR4协同作用以促进NF-κB激活，而TRAM是一个重要信号。PKCε和TRAM可能是抵抗素相关慢性动脉粥样硬化炎症的新分子靶点。
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