Expression and the pro-fibrotic effects of Mesenchyme homeobox 1 in patients with pterygium.

Pterygium is an usual ocular disease characterised by uncontrolled overgrowth conjunctive tissue invasion of the cornea. The aim of this research was to determine the expression of Mesenchyme Homeobox 1(MEOX1) in excised pterygium tissues, and to identify whether MEOX1 participates in the pathogenesis of pterygium. Subjects with primary pterygium and strabismus correction surgeries were included for this study. The expression levels of MEOX1 in all of the slides were evaluated using immunohistochemistry or quantitative Real-Time PCR (qRT-PCR). The relation between clinicopathological traits and MEOX1 expression was identified through Pearson correlation coefficient. Primary human pterygium fibroblasts (HPFs) and conjunctival fibroblasts (HConFs) were isolated and cultured in vitro. Cell proliferation and migration were assessed using Ki-67 staining and wound healing assays, respectively. Downstream of MEOX1 pathway was determined by Western blot. Immunohistochemistry showed nuclear-enriched MEOX1 localization with marked overexpression in pterygium tissues compared to controls. Moreover, MEOX1 overexpression demonstrated significant positive correlation with pterygium limbal invasion length. In vitro tests, knockdown of MEOX1 significantly inhibited HPFs' proliferation, migration and differentiation to myofibroblast. Besides, Western blot analysis revealed a significant upregulation of alpha-smooth muscle actin (α-SMA) in HPFs, while MEOX1 inhibition substantially suppressed the expression. Our results firstly found markedly elevated MEOX1 expression levels in pterygium tissues, with expression intensity showing a significant positive correlation with the invasive length of pterygium (r = 0.657, p = 0.006). In vitro, MEOX1 played a significant role in regulating the proliferation and migration of HPFs through the α-SMA pathway. These findings illuminate the potential role of MEOX1 in the pathogenesis of pterygium.