Department of Ophthalmology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan.
Biomedical Commercialization Center, Taipei Medical University, Taipei, Taiwan.
Sci Rep. 2018 May 8;8(1):7276. doi: 10.1038/s41598-018-25370-3.
Connective tissue growth factor (CTGF) associated with transforming growth factor-β (TGF-β) play a pivotal role in the pathophysiology of many fibrotic disorders. However, it is not clear whether this interaction also takes place in GO. In this study, we investigated the role of CTGF in TGF-β-induced extracellular matrix production and myofibroblast transdifferentiation in Graves' orbital fibroblasts. By Western blot analysis, we demonstrated that TGF-β1 induced the expression of CTGF, fibronectin, and alpha-smooth muscle actin (α-SMA) in Graves' orbital fibroblasts. In addition, the protein levels of fibronectin and α-SMA in Graves' orbital fibroblasts were also increased after treatment with a recombinant human protein CTGF (rhCTGF). Moreover, we transfected the orbital fibroblasts with a small hairpin RNA of CTGF gene (shCTGF) to knockdown the expression levels of CTGF, which showed that knockdown of CTGF significantly diminished TGF-β1-induced expression of CTGF, fibronectin and α-SMA proteins in Graves' orbital fibroblasts. Furthermore, the addition of rhCTGF to the shCTGF-transfected orbital fibroblasts could restore TGF-β1-induced expression of fibronectin and α-SMA proteins. Our findings demonstrate that CTGF is an essential downstream mediator for TGF-β1-induced extracellular matrix production and myofibroblast transdifferentiation in Graves' orbital fibroblasts and thus may provide with a potential therapeutic target for treatment of GO.
结缔组织生长因子 (CTGF) 与转化生长因子-β (TGF-β) 相关，在许多纤维化疾病的病理生理学中发挥关键作用。然而，尚不清楚这种相互作用是否也发生在 GO 中。在这项研究中，我们研究了 CTGF 在 Graves 眼眶成纤维细胞中 TGF-β 诱导的细胞外基质产生和肌成纤维细胞转分化中的作用。通过 Western blot 分析，我们证明 TGF-β1 诱导 CTGF、纤维连接蛋白和α-平滑肌肌动蛋白 (α-SMA) 在 Graves 眼眶成纤维细胞中的表达。此外，在 Graves 眼眶成纤维细胞中用重组人蛋白 CTGF (rhCTGF) 处理后，纤维连接蛋白和 α-SMA 的蛋白水平也增加。此外，我们用 CTGF 基因的短发夹 RNA(shCTGF) 转染眼眶成纤维细胞以敲低 CTGF 的表达水平，结果表明，敲低 CTGF 显著减少了 TGF-β1 诱导的 Graves 眼眶成纤维细胞中 CTGF、纤维连接蛋白和 α-SMA 蛋白的表达。此外，将 rhCTGF 添加到 shCTGF 转染的眼眶成纤维细胞中可以恢复 TGF-β1 诱导的纤维连接蛋白和 α-SMA 蛋白的表达。我们的研究结果表明，CTGF 是 TGF-β1 诱导 Graves 眼眶成纤维细胞中细胞外基质产生和肌成纤维细胞转分化的必需下游介质，因此可能为 GO 的治疗提供潜在的治疗靶点。
