Sphingosine 1-Phosphate Receptor 1 Is Required for MMP-2 Function in Bone Marrow Mesenchymal Stromal Cells: Implications for Cytoskeleton Assembly and Proliferation

Figure 6

MMP-2 expression and activity in MSCs cultured under hypoxic conditions. BM-MSCs were cultured for 48 h under hypoxic conditions in the absence (vehicle) or in presence of 2 μM S1PR1 receptor antagonist, W146, or 2 μM S1PR1 receptor agonist, SEW2871. (a) Representative immunofluorescence confocal images of cells cultured on glass coverslips, fixed and 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. Data are mean ± S.E.M. (c) Zymography. A representative gelatin zymography of MMP-2 from conditioned media obtained from BM-MSCs incubated in the absence (vehicle) or in the presence of 2 μM S1PR1 receptor antagonist, W146, or 2 μM S1PR1 receptor agonist, 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 the control group (vehicle) set to 100, are reported in the histogram. Data are mean ± S.E.M. Significance of differences in (b) and (c) (Student’s t-test): versus vehicle.

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