Role of Hydrogen Sulfide in the Survival of Fibroblasts and Fibroblast-mediated Contraction of Collagen Gel

Purpose: To investigate the role of hydrogen sulfide in the survival and collagen gel contraction of cultured human Tenon's capsule fibroblasts (HTCFs). Methods: Primarily cultured HTCFs were exposed to 0, 100, 200, or 300 mu M hydrogen sulfide (sodium hydrogen sulfide, NaHS) for 2 days. Cellular survival was assessed by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay. Degree of apoptosis was assessed with flow cytometry using annexin-V/propidium iodide double staining. To evaluate the effect of NaHS on cellular transdifferentiation, HTCFs were stimulated with 5 ng/mL TGF-beta 1 and the level of expression of alpha-smooth muscle actin (SMA) mRNA was assessed using reverse-transcription polymerase chain reaction. The cells were embedded in collagen gel, and the amount of gel contraction was measured. Results: NaHS at 300 mu M reduced HTCF survival (p = 0.013); NaHS at both 200 and 300 mu M increased apoptosis in a dose-dependent manner (p = 0.013 and p = 0.016). TGF-beta 1 increased the expression of alpha-SMA mRNA (p = 0.041); co-treatment with 100 mu M NaHS decreased TGF-beta 1-induced alpha-SMA mRNA expression (p = 0.039) and inhibited collagen gel contraction. Conclusions: NaHS at high concentration reduced cellular survival and increased HTCF apoptosis. NaHS decreased TGF-beta 1-induced increases in alpha-SMA mRNA expression and collagen gel contraction. Thus, hydrogen sulfide may suppress scar formation by inhibiting HTCF transdifferentiation and contraction of collagen gels.