TGF-β1-mediated upregulation of LMCD1 drives corneal myofibroblast differentiation and corneal fibrosis

Transforming growth factor β1 (TGF-β1) drives corneal fibroblasts to differentiate into corneal myofibroblasts and plays a key role in corneal fibrosis. However, the role of LIM and cysteine-rich domains-1 (LMCD1) in TGF-β1-induced corneal myofibroblast differentiation and corneal fibrosis remains elusive. Thus, this study aimed to investigate the expression, regulatory mechanism, and role of LMCD1 in TGF-β1-induced corneal myofibroblast differentiation and corneal fibrosis. The expression of LMCD1 in TGF-β1-stimulated corneal fibroblasts was found to be upregulated through mRNA sequencing, quantitative PCR (qPCR), and Western blotting. Moreover, LMCD1 was identified to be upregulated in a mouse model of corneal fibrosis via qPCR and Western blotting. Additionally, our results demonstrated that the increase in LMCD1 expression induced by TGF-β1 in corneal fibroblasts was primarily regulated by the SMAD3 signaling pathway. Furthermore, LMCD1 knockdown significantly inhibited TGF-β1-induced corneal fibroblast-to-myofibroblast differentiation and simultaneously activated SMAD3, JNK, and p38 by promoting TGF-β1 transcription. These findings collectively suggest that LMCD1 could upregulate alpha-smooth muscle actin (α-SMA) expression and downregulate TGF-β1 expression in corneal myofibroblast differentiation. Consequently, upregulation of LMCD1 expression could potentially serve as a strategy to mediate the TGF-β1 signaling pathway in corneal myofibroblast differentiation and corneal fibrosis, laying a theoretical reference for corneal fibrosis and contributing to the development of effective therapeutic strategies for corneal fibrosis.