Chiu Hsun-I, Wu Shi-Bei, Wu Albert Y, Tsai Chieh-Chih
Ophthalmology, National Yang Ming Chiao Tung University - Yangming Campus, Taipei, Taiwan.
Office of Business Development, Technology Commercialization Center, Taipei Medical University, Taipei, Taiwan.
BMJ Open Ophthalmol. 2024 Dec 25;9(1):e001693. doi: 10.1136/bmjophth-2024-001693.
There remain limited therapies to treat thyroid eye disease (TED) orbital fibrosis, highlighting the urgency to develop novel targets. Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts are important pathogenetic factor of TED. Endoplasmic reticulum (ER) stress may play a role in TED pathogenesis since it has been linked to liver, kidney, heart and lung fibrotic remodelling. We would evaluate the role of thioredoxin domain containing 5 (TXNDC5), a fibroblast-enriched ER protein, in TGF-β1-induced myofibroblast transdifferentiation from TED orbital fibroblasts.
Orbital fibroblasts from patients with TED were treated with TGF-β1 to investigate ER stress-relative gene expression especially for TXNDC5. To determine if TXNDC5 is involved in TGF-β1-induced fibrosis, we transfected TED orbital fibroblasts by lentivirus with a small hairpin RNA of pLKO-TXNDC5 gene (shTXNDC5) to knockdown TXNDC5 protein expression levels. After transfection of shTXNDC5 in TED orbital fibroblast followed by TGF-β1 treatment, we analysed TGF-β1-induced fibrosis protein expression.
We measured increased TXNDC5 gene and protein expression in primary TED orbital fibroblasts. TXNDC5 protein levels were increased in TED orbital fibroblasts under TGF-β1 stimulation (2.5, 5, 10 and 20 ng/mL). Moreover, TXNDC5 knockdown of attenuated TGFβ1 (5 ng/mL)-induced myofibroblast transdifferentiation and extracellular matrix protein upregulation whereas increasing TXNDC5 expression by a recombinant protein of TXNDC5 (rhTXNDC5) addition increased alpha smooth muscle actin, fibronectin and connective tissue growth factor protein expression.
In conclusion, targeting TXNDC5 may be a novel therapeutic approach against TGF-β1-induced myofibroblast transdifferentiation in TED orbital fibroblasts.
治疗甲状腺眼病（TED）眼眶纤维化的疗法仍然有限，这凸显了开发新靶点的紧迫性。转化生长因子-β1（TGF-β1）诱导眼眶成纤维细胞转分化为肌成纤维细胞是TED的重要致病因素。内质网（ER）应激可能在TED发病机制中起作用，因为它与肝、肾、心和肺的纤维化重塑有关。我们将评估富含成纤维细胞的内质网蛋白含硫氧还蛋白结构域5（TXNDC5）在TGF-β1诱导的TED眼眶成纤维细胞向肌成纤维细胞转分化中的作用。
用TGF-β1处理TED患者的眼眶成纤维细胞，以研究内质网应激相关基因的表达，特别是TXNDC5的表达。为了确定TXNDC5是否参与TGF-β1诱导的纤维化，我们用携带pLKO-TXNDC5基因小发夹RNA（shTXNDC5）的慢病毒转染TED眼眶成纤维细胞，以降低TXNDC5蛋白表达水平。在TED眼眶成纤维细胞中转染shTXNDC5后再进行TGF-β1处理，我们分析了TGF-β1诱导的纤维化蛋白表达。
我们检测到原发性TED眼眶成纤维细胞中TXNDC5基因和蛋白表达增加。在TGF-β1刺激（2.5、5、10和20 ng/mL）下，TED眼眶成纤维细胞中的TXNDC5蛋白水平升高。此外，TXNDC5的敲低减弱了TGFβ1（5 ng/mL）诱导的肌成纤维细胞转分化和细胞外基质蛋白上调，而通过添加TXNDC5重组蛋白（rhTXNDC5）增加TXNDC5表达则增加了α平滑肌肌动蛋白、纤连蛋白和结缔组织生长因子蛋白表达。
总之，靶向TXNDC5可能是一种针对TGF-β1诱导的TED眼眶成纤维细胞向肌成纤维细胞转分化的新治疗方法。
