Hydrogen sulfide increases hepatic differentiation in tooth-pulp stem cells

摘要

The toxicity of hydrogen sulfide (H _2S), an oral malodorous compound, is well reported. We have recently established an experimental model of hepatic differentiation from human tooth-pulp stem cells (HTPC) using serum-free medium. The objective of the present study is to determine the effect of H _2S on hepatic differentiation. The CD117 positive cell fraction was obtained from deciduous HTPC using magnetic cell sorting. After 3-4 passages, cells were grown in Dulbecco's modified Eagle's medium supplemented with insulin-transferrin-selenium-x (ITS-x), embryotrophic factor (ETF) and hepatocyte growth factor (HGF) for hepatic commitment (five days). For hepatic differentiation the cells were cultured in Iscove's modified Dulbecco's medium supplemented with ITS-x, ETF, oncostatin, HGF and dexamethasone for 15 days in air containing 5% CO _2, with or without H _2S at 0.05 ng ml ~(-1). Cells were assayed for the expression of hepatic markers α-fetoprotein, albumin or carbamoyl phosphate synthetase, and urea concentrations and glycogen synthesis were also determined. The panel of hepatic markers was expressed more in the test groups exposed to H _2S than in the control groups. Urea and glycogen production were also increased, especially glycogen which was approximately five times greater compared to the control (p < 0.01). We concluded that H _2S at physiological concentrations increased the ability of HTPC to undergo hepatogenic differentiation.