受体蛋白酪氨酸磷酸酶α介导的类风湿性滑膜成纤维细胞信号增强及关节炎在小鼠中的促进作用。
Receptor Protein Tyrosine Phosphatase α-Mediated Enhancement of Rheumatoid Synovial Fibroblast Signaling and Promotion of Arthritis in Mice.
机构信息
La Jolla Institute for Allergy and Immunology, La Jolla, California.
The Scripps Research Institute, La Jolla, California.
出版信息
Arthritis Rheumatol. 2016 Feb;68(2):359-69. doi: 10.1002/art.39442.
OBJECTIVE
During rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) critically promote disease pathogenesis by aggressively invading the extracellular matrix of the joint. The focal adhesion kinase (FAK) signaling pathway is emerging as a contributor to the anomalous behavior of RA FLS. The receptor protein tyrosine phosphatase α (RPTPα), which is encoded by the PTPRA gene, is a key promoter of FAK signaling. The aim of this study was to investigate whether RPTPα mediates FLS aggressiveness and RA pathogenesis.
METHODS
Through RPTPα knockdown, we assessed FLS gene expression by quantitative polymerase chain reaction analysis and enzyme-linked immunosorbent assay, invasion and migration by Transwell assays, survival by annexin V and propidium iodide staining, adhesion and spreading by immunofluorescence microscopy, and activation of signaling pathways by Western blotting of FLS lysates. Arthritis development was examined in RPTPα-knockout (KO) mice using the K/BxN serum-transfer model. The contribution of radiosensitive and radioresistant cells to disease was evaluated by reciprocal bone marrow transplantation.
RESULTS
RPTPα was enriched in the RA synovial lining. RPTPα knockdown impaired RA FLS survival, spreading, migration, invasiveness, and responsiveness to platelet-derived growth factor, tumor necrosis factor, and interleukin-1 stimulation. These phenotypes correlated with increased phosphorylation of Src on inhibitory Y(527) and decreased phosphorylation of FAK on stimulatory Y(397) . Treatment of RA FLS with an inhibitor of FAK phenocopied the knockdown of RPTPα. RPTPα-KO mice were protected from arthritis development, which was due to radioresistant cells.
CONCLUSION
By regulating the phosphorylation of Src and FAK, RPTPα mediates proinflammatory and proinvasive signaling in RA FLS, correlating with the promotion of disease in an FLS-dependent model of RA.
目的
在类风湿关节炎（RA）中，成纤维样滑膜细胞（FLS）通过积极侵袭关节细胞外基质，对疾病发病机制起着关键作用。黏着斑激酶（FAK）信号通路是 RA FLS 异常行为的一个贡献因素。受体蛋白酪氨酸磷酸酶 α（RPTPα）由 PTPRA 基因编码，是 FAK 信号的关键促进剂。本研究旨在探讨 RPTPα 是否介导 FLS 侵袭性和 RA 发病机制。
方法
通过 RPTPα 敲低，我们通过定量聚合酶链反应分析和酶联免疫吸附试验评估 FLS 基因表达，通过 Transwell 测定侵袭和迁移，通过 Annexin V 和碘化丙啶染色评估存活，通过免疫荧光显微镜评估粘附和扩散，通过 Western blot 分析 FLS 裂解物中的信号通路激活。使用 K/BxN 血清转移模型在 RPTPα 敲除（KO）小鼠中检查关节炎的发展。通过互惠骨髓移植评估辐射敏感和辐射抗性细胞对疾病的贡献。
结果
RPTPα 在 RA 滑膜衬里中富集。RPTPα 敲低会损害 RA FLS 的存活、扩散、迁移、侵袭和对血小板衍生生长因子、肿瘤坏死因子和白细胞介素-1 刺激的反应性。这些表型与 Src 在抑制性 Y(527)上的磷酸化增加和 FAK 在刺激性 Y(397)上的磷酸化减少相关。RA FLS 中 FAK 抑制剂的治疗可模拟 RPTPα 的敲低。RPTPα-KO 小鼠免受关节炎发展的影响，这归因于辐射抗性细胞。
结论
通过调节 Src 和 FAK 的磷酸化，RPTPα 介导 RA FLS 中的促炎和侵袭性信号，与 FLS 依赖性 RA 模型中疾病的促进相关。
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