Sphingosine 1-Phosphate Receptor 1 Is Required for MMP-2 Function in Bone Marrow Mesenchymal Stromal Cells: Implications for Cytoskeleton Assembly and Proliferation
MMP-2 expression and activity. BM-MSCs were cultured for 48 h in the absence (vehicle) or in presence of 1 μM exogenous sphingosine-1-phosphate (exoS1P) or 2 μM S1PR1 receptor antagonist, W146, or 2 μM S1PR1 receptor agonist, SEW2871. (a) Representative immunofluorescence confocal images of fixed cells on glass coverslips immunostained with antibodies against MMP-2 (green). Scale bar 50 μm. The images are representative of at least three independent experiments with similar results. (b) Densitometric analysis of the intensity of the MMP-2 fluorescence signal performed on digitized images. (c) Zymography. A representative gelatin zymography of MMP-2 from conditioned media obtained from BM-MSCs incubated in absence (vehicle) or in presence of W146 or SEW2871 for 48 h. Densitometry scanning from at least three separate experiments was performed and data, expressed as relative OD values (a.u.) to those of control group (vehicle) set to 100, are reported in the histogram. Data are mean ± S.E.M. Significance of difference in (b) (one-way ANOVA and Newman-Keuls multiple comparison tests), versus vehicle, versus SEW2871; in (c) (Student’s t-test), versus vehicle.