细胞因子信号转导抑制因子(SOCS)1通过蛋白酶体调节单核细胞和巨噬细胞中白细胞介素-4(IL-4)激活的胰岛素受体底物(IRS)-2酪氨酸磷酸化。
Suppressor of Cytokine Signaling (SOCS)1 Regulates Interleukin-4 (IL-4)-activated Insulin Receptor Substrate (IRS)-2 Tyrosine Phosphorylation in Monocytes and Macrophages via the Proteasome.
作者信息
McCormick Sarah M, Gowda Nagaraj, Fang Jessie X, Heller Nicola M
机构信息
From the Department of Anesthesiology and Critical Care Medicine and.
From the Department of Anesthesiology and Critical Care Medicine and Division of Allergy and Clinical Immunology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
出版信息
J Biol Chem. 2016 Sep 23;291(39):20574-87. doi: 10.1074/jbc.M116.746164. Epub 2016 Aug 9.
Allergic asthma is a chronic lung disease initiated and driven by Th2 cytokines IL-4/-13. In macrophages, IL-4/-13 bind IL-4 receptors, which signal through insulin receptor substrate (IRS)-2, inducing M2 macrophage differentiation. M2 macrophages correlate with disease severity and poor lung function, although the mechanisms that regulate M2 polarization are not understood. Following IL-4 exposure, suppressor of cytokine signaling (SOCS)1 is highly induced in human monocytes. We found that siRNA knockdown of SOCS1 prolonged IRS-2 tyrosine phosphorylation and enhanced M2 differentiation, although siRNA knockdown of SOCS3 did not affect either. By co-immunoprecipitation, we found that SOCS1 complexes with IRS-2 at baseline, and this association increased after IL-4 stimulation. Because SOCS1 is an E3 ubiquitin ligase, we examined the effect of proteasome inhibitors on IL-4-induced IRS-2 phosphorylation. Proteasomal inhibition prolonged IRS-2 tyrosine phosphorylation, increased ubiquitination of IRS-2, and enhanced M2 gene expression. siRNA knockdown of SOCS1 inhibited ubiquitin accumulation on IRS-2, although siRNA knockdown of SOCS3 had no effect on ubiquitination of IRS-2. Monocytes from healthy and allergic individuals revealed that SOCS1 is induced by IL-4 in healthy monocytes but not allergic cells, whereas SOCS3 is highly induced in allergic monocytes. Healthy monocytes displayed greater ubiquitination of IRS-2 and lower M2 polarization than allergic monocytes in response to IL-4 stimulation. Here, we identify SOCS1 as a key negative regulator of IL-4-induced IRS-2 signaling and M2 differentiation. Our findings provide novel insight into how dysregulated expression of SOCS increases IL-4 responses in allergic monocytes, and this may represent a new therapeutic avenue for managing allergic disease.
过敏性哮喘是一种由Th2细胞因子IL-4/-13引发并驱动的慢性肺部疾病。在巨噬细胞中,IL-4/-13与IL-4受体结合,通过胰岛素受体底物(IRS)-2发出信号,诱导M2巨噬细胞分化。M2巨噬细胞与疾病严重程度和肺功能不佳相关,尽管调节M2极化的机制尚不清楚。在暴露于IL-4后,细胞因子信号转导抑制因子(SOCS)1在人单核细胞中被高度诱导。我们发现,敲低SOCS1的小干扰RNA(siRNA)可延长IRS-2酪氨酸磷酸化并增强M2分化,而敲低SOCS3的siRNA则没有任何影响。通过免疫共沉淀,我们发现SOCS1在基线时与IRS-2形成复合物,并且这种结合在IL-4刺激后增加。由于SOCS1是一种E3泛素连接酶,我们研究了蛋白酶体抑制剂对IL-4诱导的IRS-2磷酸化的影响。蛋白酶体抑制可延长IRS-2酪氨酸磷酸化,增加IRS-2的泛素化,并增强M2基因表达。敲低SOCS1的siRNA可抑制IRS-2上泛素的积累,而敲低SOCS3的siRNA对IRS-2的泛素化没有影响。来自健康个体和过敏个体的单核细胞显示,健康单核细胞中的SOCS1可被IL-4诱导,而过敏细胞中则不然,而SOCS3在过敏单核细胞中被高度诱导。在IL-4刺激下,健康单核细胞比过敏单核细胞表现出更高的IRS-2泛素化和更低的M2极化。在此,我们确定SOCS1是IL-4诱导的IRS-2信号传导和M2分化的关键负调节因子。我们的研究结果为SOCS表达失调如何增加过敏单核细胞中IL-4反应提供了新的见解,这可能代表了一种治疗过敏性疾病的新途径。