Fig. 5.

Positive regulation of TGF-β1 by S1P and SK1 subcellular localization by TGF-β1 in fHASCs. Quantification of latency-associated peptide (LAP) on cell surface of fHASCs by FACS (A) and of secreted TGF-β1 by ELISA (B) in fHASCs cultured for 24 h in stem cell medium, supplemented with delipidated serum, either as such or containing different concentrations of S1P. Data are means ± S.D. of three independent experiments. **P < 0.01, ***P < 0.001; ANOVA and Dunnett test (treatments vs. medium control). Effect of TGF-β1 on SK1 and SK2 subcellular localization. Serum fHASCs were incubated with 10 ng/ml TGF-β1 for 10 min. Western analysis of SK1 (C) and SK2 (d) was performed in membrane and cytosolic fractions. Representative Western blots and relative histograms depicting densitometric analysis of immunoblots of SK1 (C) or SK2 (D) bands in three independent experiments. Data reported as fold increase over untreated control of the membrane/cytosol ratio for SK1 and for SK2. * P < 0.05, Student's t-test.