Inflammatory properties of inhibitor of DNA binding 1 secreted by synovial fibroblasts in rheumatoid arthritis
Inflammatory properties of inhibitor of DNA binding 1 secreted by synovial fibroblasts in rheumatoid arthritis
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DOI：
10.1186/s13075-016-0984-3
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发表时间：
2016-04-12
影响因子：
4.9
通讯作者：
Ruth, Jeffrey H.
中科院分区：
文献类型：
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作者：
Edhayan, Gautam;Ohara, Ray A.;Ruth, Jeffrey H.
背景资料：DNA结合抑制因子1（Inhibitor of DNA binding 1，Id 1）是一种核蛋白，含有一个碱性螺旋-环-螺旋（basic helix-loop-helix，bHLH）结构域，通过选择性结合和阻止基因转录来调节细胞生长。类风湿性关节炎滑膜组织（RA ST）的Id 1生产的来源及其在RA中的功能作用的范围仍有待澄清。方法：我们分析了Id 1从滑膜成纤维细胞和内皮细胞（ECs）与组织学和实时聚合酶链反应（RT-PCR）。通过酶联免疫吸附测定（ELISA）测量进行差速离心以分离和纯化外泌体的成纤维细胞上清液的Id 1。对Id 1刺激的EC进行Western印迹以确定细胞内蛋白磷酸化的动力学。随后用沉默RNA（siRNA）靶向Id 1诱导的EC细胞内信号通路以抑制血管生成。结果：通过PCR和组织学分析，我们发现ST中Id 1的主要来源是与人RA ST和K/BxN血清诱导小鼠关节炎性评分相关的活化成纤维细胞。正常（NL）和RA滑膜成纤维细胞通过转化生长因子β（TGF-β）的刺激增加Id 1的产生。RA滑膜成纤维细胞释放的大部分Id 1包含在外来体中。内皮祖细胞（EPCs）和人真皮微血管内皮细胞（HMVECs）激活Jnk信号通路响应Id 1，和Jnk siRNA逆转Id 1诱导的HMVEC血管形成Matrigel plugs in vivo.Conclusions：Id 1是一个多效性分子，影响血管生成，血管生成和纤维化。我们的数据表明，Id 1不仅是一种重要的核蛋白，而且可以通过外泌体从成纤维细胞释放。细胞外Id 1激活信号通路的能力扩大了Id 1在组织炎症协调中的作用。
Background: Inhibitor of DNA binding 1 (Id1) is a nuclear protein containing a basic helix-loop-helix (bHLH) domain that regulates cell growth by selective binding and prevention of gene transcription. Sources of Id1 production in rheumatoid arthritis synovial tissue (RA ST) and its range of functional effects in RA remain to be clarified.Methods: We analyzed Id1 produced from synovial fibroblasts and endothelial cells (ECs) with histology and real-time polymerase chain reaction (RT-PCR). Fibroblast supernatants subjected to differential centrifugation to isolate and purify exosomes were measured for Id1 by enzyme-linked immunosorbent assay (ELISA). Western blotting of Id1-stimulated ECs was performed to determine the kinetics of intracellular protein phosphorylation. EC intracellular signaling pathways induced by Id1 were subsequently targeted with silencing RNA (siRNA) for angiogenesis inhibition.Results: By PCR and histologic analysis, we found that the primary source of Id1 in STs is from activated fibroblasts that correlate with inflammatory scores in human RA ST and in joints from K/BxN serum-induced mice. Normal (NL) and RA synovial fibroblasts increase Id1 production with stimulation by transforming growth factor beta (TGF-beta). Most of the Id1 released by RA synovial fibroblasts is contained within exosomes. Endothelial progenitor cells (EPCs) and human dermal microvascular ECs (HMVECs) activate the Jnk signaling pathway in response to Id1, and Jnk siRNA reverses Id1-induced HMVEC vessel formation in Matrigel plugs in vivo.Conclusions: Id1 is a pleotropic molecule affecting angiogenesis, vasculogenesis, and fibrosis. Our data shows that Id1 is not only an important nuclear protein, but also can be released from fibroblasts via exosomes. The ability of extracellular Id1 to activate signaling pathways expands the role of Id1 in the orchestration of tissue inflammation.