Purpose: Due to its ability to disrupt transforming growth factor beta (TGF-β) signaling, halofuginone has been successfully used to treat various fibrotic disorders. Here we investigated the antifibrotic potential of halofuginone in human corneal fibroblasts. Methods: Human corneal fibroblasts were isolated from human donor corneas for in vitro experiments. TGF-β was used to stimulate pro-fibrotic responses from corneal fibroblasts under halofuginone treatment. The expression of alpha smooth muscle actin (α-SMA) and fibronectin was analyzed by western blots. Phalloidin toxin was used to stain cultures for stress fiber assemblies. Quantitative reverse transcription PCR (qRT-PCR) and immunostaining were used to analyze the expression of type I collagen mRNA and protein, respectively. The expression of Smad2, Smad3, phospho-Smad2, and phospho-Smad3 was determined by western blots. Results: Halofuginone was well tolerated by human corneal fibroblasts up to 10 ng/ml as demonstrated by a cell viability assay. At this concentration, TGF-β-induced expression of the fibrotic markers α-SMA, fibronectin, and type I collagen was significantly reduced. Interestingly, under our experimental conditions, halofuginone treatment led to reduced protein expression of Smad3, which was both dose- and time-dependent. Conclusions: Our results suggest that halofuginone may exert its antifibrotic effects in the cornea via a novel molecular mechanism and may be used as an antifibrotic agent for corneal fibrosis treatment.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Feb 18 2012|