PS1/γ-Secretase-Mediated Cadherin Cleavage Induces β-Catenin Nuclear Translocation and Osteogenic Differentiation of Human Bone Marrow Stromal Cells

Figure 1

Osteogenic medium, but not Wnt3a-CM, induces β-catenin signaling and BMSCs osteogenic differentiation. (a) BMSCs were cultured in osteogenic medium (OM) for 48 h and 5 days and Axin-2 mRNA fold increase was evaluated. Bars represent mean ± SD of 3 independent experiments performed in triplicate. (b) Luciferase activity in BMSCs containing a SuperTop TCF reporter, osteoinduced for 48 h and 5 days with incomplete osteogenic medium (iOM, without dexamethasone), osteogenic medium (OM), or iOM containing 10% or 50% Wnt3a-CM. CT = undifferentiated cells. Bars represent mean ± SD of 4 experiments performed in triplicate. (c) Alkaline phosphatase activity in BMSC cultures after 7 and 14 days of osteoinduction with OM or iOM containing 1%, 5%, and 10% Wnt3a-CM. iOM supplemented with Wnt3a-CM was added at the onset of induction (0 h) or after 48 h and 4 days of osteoinduction with OM. Mean ± SD of 5 independent experiments with triplicates is shown. .

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