Antibody-mediated inhibition of syndecan-4 dimerisation reduces interleukin (IL)-1 receptor trafficking and signalling
Antibody-mediated inhibition of syndecan-4 dimerisation reduces interleukin (IL)-1 receptor trafficking and signalling
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DOI：
10.1136/annrheumdis-2019-216847
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发表时间：
2020-04-01
影响因子：
27.4
通讯作者：
Bertrand, Jessica
中科院分区：
文献类型：
--
作者：
Godmann, Lars;Bollmann, Miriam;Bertrand, Jessica
SDC 4是一种细胞锚定的蛋白聚糖，由跨膜核心蛋白和葡糖胺聚糖（GAG）侧链组成。可溶性因子与sdc 4的GAG链的结合可能导致sdc 4的二聚化和下游信号级联的启动。然而，sdc 4二聚化和信号传导如何影响细胞对炎症刺激的反应的问题尚不清楚。方法对类风湿性关节炎（RA）组织切片进行Sdc 4免疫染色。研究白细胞介素（IL）-1诱导细胞外信号调节激酶（ERK）磷酸化和基质金属蛋白酶-3的产生。使用免疫沉淀法研究Il-1与sdc 4的结合。在荧光激活细胞分选分析中对野生型、sdc 4和IL 1 R1敲除成纤维细胞进行IL-1受体（IL 1 R1）染色。一个封闭的sdc 4抗体被用来调查sdc 4二聚化，IL 1 R1的表达和组织学爪破坏中的人肿瘤坏死因子-α转基因mouse.ResultsWe表明，在成纤维细胞，sdc 4的损失或抗体介导的抑制sdc 4二聚化降低细胞表面表达的IL-1 R和调节成纤维细胞对IL-1的敏感性。我们证明，IL-1直接结合sdc 4和IL-1 R-独立的方式导致其二聚化。IL-1诱导的sdc 4二聚化调节小窝蛋白囊泡介导的IL 1 R1运输，这反过来又决定了对IL-1的反应性。管理的抗体（Ab）对sdc 4的二聚化结构域，因此，强烈降低了表达IL 1 R1关节炎成纤维细胞在体外和动物模型的人RA.ConclusionCollectively，我们的数据表明，抗体特异性抑制sdc 4二聚化可能支持抗IL-1的策略，如炎症性关节炎的疾病。
ObjectiveSyndecan-4 (sdc4) is a cell-anchored proteoglycan that consists of a transmembrane core protein and glucosaminoglycan (GAG) side chains. Binding of soluble factors to the GAG chains of sdc4 may result in the dimerisation of sdc4 and the initiation of downstream signalling cascades. However, the question of how sdc4 dimerisation and signalling affects the response of cells to inflammatory stimuli is unknown.MethodsSdc4 immunostaining was performed on rheumatoid arthritis (RA) tissue sections. Interleukin (IL)-1 induced extracellular signal-regulated kinases (ERK) phosphorylation and matrix metalloproteinase-3 production was investigated. Il-1 binding to sdc4 was investigated using immunoprecipitation. IL-1 receptor (IL1R1) staining on wild-type, sdc4 and IL1R1 knockout fibroblasts was performed in fluorescence-activated cell sorting analyses. A blocking sdc4 antibody was used to investigate sdc4 dimerisation, IL1R1 expression and the histological paw destruction in the human tumour necrosis factor-alpha transgenic mouse.ResultsWe show that in fibroblasts, the loss of sdc4 or the antibody-mediated inhibition of sdc4 dimerisation reduces the cell surface expression of the IL-1R and regulates the sensitivity of fibroblasts to IL-1. We demonstrate that IL-1 directly binds to sdc4 and in an IL-1R-independent manner leads to its dimerisation. IL-1-induced dimerisation of sdc4 regulates caveolin vesicle-mediated trafficking of the IL1R1, which in turn determines the responsiveness to IL-1. Administration of antibodies (Ab) against the dimerisation domain of sdc4, thus, strongly reduces the expression IL1R1 on arthritic fibroblasts both in vitro and an animal model of human RA.ConclusionCollectively, our data suggest that Ab that specifically inhibit sdc4 dimerisation may support anti-IL-1 strategies in diseases such as inflammatory arthritis.