Modulation of monosodium urate crystal-induced responses in neutrophils by the myeloid inhibitory C-type lectin-like receptor: potential therapeutic implications
Modulation of monosodium urate crystal-induced responses in neutrophils by the myeloid inhibitory C-type lectin-like receptor: potential therapeutic implications
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DOI：
10.1186/ar4250
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发表时间：
2013-01-01
影响因子：
4.9
通讯作者：
Fernandes, Maria J. G.
中科院分区：
文献类型：
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作者：
Gagne, Valerie;Marois, Louis;Fernandes, Maria J. G.
简介：尿酸钠晶体 (MSU) 是痛风的病因，是对中性粒细胞最有效的促炎刺激物之一。抑制性受体对 MSU 诱导的中性粒细胞激活的调节仍知之甚少。中性粒细胞中骨髓抑制性 C 型凝集素样受体 (MICL) 的表达会受到多种促炎刺激的下调，表明该受体在中性粒细胞功能中发挥作用。因此，我们研究了 MICL 在 MSU 诱导的中性粒细胞活化中的潜在作用。方法：在用 MSU 刺激后，通过流式细胞术和蛋白质印迹分析监测人中性粒细胞中 MICL 的表达。还通过蛋白质印迹分析评估了蛋白质酪氨酸磷酸化，并通过酶联免疫吸附测定评估了 IL-1 和 IL-8 的产生。用 Fura-2-乙酰氧基甲酯钙指示剂监测细胞质游离钙浓度的变化。在中性粒细胞中使用抗 MICL 抗体，在 PLB-985 中性粒细胞样细胞系中使用 siRNA 调节 MICL 表达。结果：MSU 诱导中性粒细胞中 MICL 表达下调。抗体交联或 siRNA 诱导的 MICL 表达减少增强了 MSU 依赖性细胞质钙水平、蛋白酪氨酸磷酸化和 IL-8 的增加，但不增强 IL-1 的产生。用秋水仙碱预处理中性粒细胞可抑制 MSU 诱导的 MICL 表达下调。结论：我们的研究结果强烈表明 MICL 在人中性粒细胞中充当抑制性受体，因为 MICL 表达的下调增强了 MSU 诱导的中性粒细胞活化。由于 MSU 下调 MICL 的表达，因此 MICL 可能通过增强中性粒细胞效应功能而在痛风中发挥致病作用。为了支持这一观点，秋水仙碱可以抵消 MSU 诱导的 MICL 表达缺失。因此，我们的研究结果还进一步深入了解了该药物抗炎特性背后的潜在分子机制。
Introduction: Monosodium urate crystals (MSU), the etiological agent of gout, are one of the most potent proinflammatory stimuli for neutrophils. The modulation of MSU-induced neutrophil activation by inhibitory receptors remains poorly characterized. The expression of the myeloid inhibitory C-type lectin-like receptor (MICL) in neutrophils is downregulated by several proinflammatory stimuli, suggestive of a role for this receptor in neutrophil function. We thus investigated the potential role of MICL in MSU-induced neutrophil activation.Methods: The expression of MICL was monitored in human neutrophils by flow cytometry and Western blot analysis after stimulation with MSU. Protein tyrosine phosphorylation was also assessed by Western blot analysis and the production of IL-1 and IL-8 by enzyme-linked immunosorbent assay. Changes in the concentration of cytoplasmic free calcium were monitored with the Fura-2-acetoxymethyl ester calcium indicator. MICL expression was modulated with an anti-MICL antibody in neutrophils and siRNA in the PLB-985 neutrophil-like cell line.Results: MSU induced the downregulation of MICL expression in neutrophils. A diminution in the expression of MICL induced by antibody cross-linking or siRNA enhanced the MSU-dependent increase in cytoplasmic calcium levels, protein tyrosine phosphorylation and IL-8 but not IL-1 production. Pretreatment of neutrophils with colchicine inhibited the MSU-induced downregulation of MICL expression.Conclusions: Our findings strongly suggest that MICL acts as an inhibitory receptor in human neutrophils since the downregulation of MICL expression enhances MSU-induced neutrophil activation. Since MSU downregulates the expression of MICL, MICL may play a pathogenic role in gout by enhancing neutrophil effector functions. In support of this notion, colchicine counteracts the MSU-induced loss of MICL expression. Our findings thus also provide further insight into the potential molecular mechanisms behind the anti-inflammatory properties of this drug.