Tyrosine phosphatase SHP-2 regulates IL-1 signaling in fibroblasts through focal adhesions
Tyrosine phosphatase SHP-2 regulates IL-1 signaling in fibroblasts through focal adhesions
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DOI：
10.1002/jcp.20544
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发表时间：
2006-04-01
影响因子：
5.6
通讯作者：
Downey, GP
中科院分区：
文献类型：
--
作者：
Abreu, MTH;Wang, Q;Downey, GP
白细胞介素-1 β（IL-1 β）通过激活成纤维细胞介导多种炎性疾病（包括关节炎、牙周炎和肺纤维化）中基质胶原的破坏，成纤维细胞是通过基于整合素的粘附与基质蛋白相互作用的细胞。在体外，IL-1 β信号传导由粘着斑、富含酪氨酸激酶和磷酸酶的超分子蛋白复合物调节。我们评估了酪氨酸磷酸酶在调节细胞-基质相互作用和IL-1 β信号传导中的重要性。在铺在纤连蛋白上的人牙龈成纤维细胞中，IL-1 β增强了由形态学和桩蛋白和α-辅肌动蛋白富集所定义的粘着斑的成熟。IL-1 β还诱导ERK的活化和磷酸化ERK向局灶性复合物/粘连的募集。在不存在IL-1 β的情况下，用有效的酪氨酸磷酸酶抑制剂过钒酸盐治疗，重现了许多这些反应，表明酪氨酸磷酸酶的重要性。胶原珠相关复合物的免疫印迹显示，酪氨酸磷酸酶，SHP-2，也富集在局灶性复合物/粘连。通过siRNA或同源重组耗尽SHP-2显著改变了IL-1 β诱导的ERK活化和粘着斑的成熟。IL-1 β诱导的SHP-2在Y542残基上的酪氨酸磷酸化促进粘着斑成熟。关联的Gab1与SHP-2在局灶性粘连与ERK的激活时间相关，并废除在细胞表达突变体（Y542F）SHP-2。我们得出结论，IL-1 β介导的粘着斑的成熟依赖于SHP-2在Y542的酪氨酸磷酸化，导致Gab1的募集，这是一个可能影响ERK下游激活的过程。
Interleukin-1 beta (IL-1 beta) mediates destruction of matrix collagens in diverse inflammatory diseases including arthritis, periodontitis, and pulmonary fibrosis by activating fibroblasts, cells that interact with matrix proteins through integrin-based adhesions. In vitro, IL-1 beta signaling is modulated by focal adhesions, supramolecular protein complexes that are enriched with tyrosine kinases and phosphatases. We assessed the importance of tyrosine phosphatases in regulating cell-matrix interactions and IL-1 beta signaling. In human gingival fibroblasts plated on fibronectin, IL-1 beta enhanced the maturation of focal adhesions as defined by morphology and enrichment with paxillin and a-actinin. IL-1 beta also induced activation of ERK and recruitment of phospho-ERK to focal complexes/ adhesions. Treatment with the potent tyrosine phosphatase inhibitor pervanadate, in the absence of IL-1 beta, recapitulated many of these responses indicating the importance of tyrosine phosphatases. Immunoblotting of collagen bead-associated complexes revealed that the tyrosine phosphatase, SHP-2, was also enriched in focal complexes/adhesions. Depletion of SHP-2 by siRNA or by homologous recombination markedly altered IL-1 beta-induced ERK activation and maturation of focal adhesions. IL-1 beta-induced tyrosine phosphorylation of SHP-2 on residue Y542 promoted focal adhesion maturation. Association of Gab1 with SHP-2 in focal adhesions correlated temporally with activation of ERK and was abrogated in cells expressing mutant (Y542F) SHP-2. We conclude that IL-1 beta mediated maturation of focal adhesions is dependent on tyrosine phosphorylation of SHP-2 at Y542, leading to recruitment of Gab1, a process that may influence the downstream activation of ERK.