Effects of N-acetylcysteine on matrix metalloproteinase-9 secretion and cell migration of human corneal epithelial cells

Abstract

Matrix metalloproteinase-9 (MMP-9) secreted by corneal epithelial cells has a role in the remodelling of extracellular matrix and migration of epithelial cells. Elevated levels of MMP-9 activity in the ocular surface may be involved in the pathogenesis of corneal diseases. N-acetylcysteine (NAC) has been used to treat corneal diseases, including recurrent epithelial erosions. In this study, its effects on the MMP-9 secretion and human corneal epithelial (HCE) cell migration were evaluated in vitro. Confluent HCE cell cultures were treated with 0-20 mM NAC, and tested for MMP-9 secretion and epithelial cell migration by gelatin zymography and scratch wound assay, respectively. Comparisons between different treatment groups were made using analysis of variance, followed by multiple pairwise comparisons. Twenty mM NAC inhibited the secretion of MMP-9 significantly. Cell migration, assessed after 24 h of wounding, showed a highly significant dose-dependent inhibitory effect. This study shows that NAC reduces MMP-9 production by HCE cells and inhibits cell migration in vitro. This information helps to elucidate the mechanisms by which NAC may be beneficial therapeutically and suggests that NAC may be useful for managing corneal erosions and related conditions.