Department of Immunology, Erasmus Medical Center, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.
J Clin Endocrinol Metab. 2012 Jun;97(6):E944-53. doi: 10.1210/jc.2012-1020. Epub 2012 Mar 21.
Thyroid-stimulating hormone receptor (TSHR) stimulating autoantibodies are associated with Graves' ophthalmopathy (GO), the orbital manifestation of Graves' disease (GD). TSHR autoantibody levels and orbital TSHR expression levels correlate positively with GO disease activity. Platelet-derived growth factors (PDGF) are increased in GO and potently activate orbital fibroblast effector functions. We investigated the possible relationship between PDGF and TSHR expression on orbital fibroblasts and how that influences the immunopathological effects of TSHR autoantibodies on orbital fibroblast activity.
Orbital fibroblasts were stimulated with PDGF-AA, PDGF-AB, and PDGF-BB, and TSHR expression was determined by flow cytometry. Stimulatory effects of bovine TSH and GD immunoglobulins on orbital fibroblasts (with or without PDGF-BB preincubation) were determined by IL-6, IL-8, chemokine (C-C motif) ligand (CCL)-2, CCL5, CCL7, and hyaluronan ELISA. The TSHR blocking antibody K1-70 and the cAMP inhibitor H89 were used to determine involvement of TSHR signaling.
PDGF-AB and PDGF-BB stimulation increased TSHR expression on orbital fibroblasts, whereas PDGF-AA did not. Furthermore, stimulation with bovine TSH and immunoglobulins from GD patients induced IL-6, IL-8, CCL2, and hyaluronan production by orbital fibroblasts, and PDGF-BB preincubation enhanced this response of orbital fibroblasts. Blocking studies with a TSHR blocking antibody and a cAMP inhibitor inhibited these effects, indicating the involvement of TSHR signaling and thus of TSHR stimulating autoantibodies herein.
These findings indicate that PDGF-B containing PDGF isoforms amplify the immunopathological effects of TSHR-stimulating autoantibodies in GO patients by stimulating TSHR expression on orbital fibroblasts.
促甲状腺激素受体（TSHR）刺激自身抗体与 Graves 眼病（GO）有关，GO 是 Graves 病（GD）的眼眶表现。TSHR 自身抗体水平和眼眶 TSHR 表达水平与 GO 疾病活动呈正相关。血小板衍生生长因子（PDGF）在 GO 中增加，并强烈激活眼眶成纤维细胞效应功能。我们研究了 PDGF 与眼眶成纤维细胞上的 TSHR 表达之间的可能关系，以及这如何影响 TSHR 自身抗体对眼眶成纤维细胞活性的免疫病理作用。
用 PDGF-AA、PDGF-AB 和 PDGF-BB 刺激眼眶成纤维细胞，并用流式细胞术测定 TSHR 表达。通过 IL-6、IL-8、趋化因子（C-C 基序）配体（CCL）-2、CCL5、CCL7 和透明质酸 ELISA 测定牛 TSH 和 GD 免疫球蛋白对眼眶成纤维细胞的刺激作用（有无 PDGF-BB 预孵育）。使用 TSHR 阻断抗体 K1-70 和 cAMP 抑制剂 H89 来确定 TSHR 信号转导的参与。
PDGF-AB 和 PDGF-BB 刺激增加了眼眶成纤维细胞上的 TSHR 表达，而 PDGF-AA 则没有。此外，牛 TSH 和 GD 患者的免疫球蛋白刺激诱导了眼眶成纤维细胞产生 IL-6、IL-8、CCL2 和透明质酸，而 PDGF-BB 预孵育增强了眼眶成纤维细胞的这种反应。TSHR 阻断抗体和 cAMP 抑制剂的阻断研究抑制了这些作用，表明 TSHR 信号转导的参与，因此也参与了本文中的 TSHR 刺激自身抗体。
这些发现表明，含有 PDGF-B 的 PDGF 同工型通过刺激眼眶成纤维细胞上的 TSHR 表达，放大了 GO 患者 TSHR 刺激自身抗体的免疫病理作用。
