Periostin: A Downstream Mediator of EphB4-Induced Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

Figure 2

Activation of EphB4 increased POSTN expression in MSCs. (a) POSTN mRNA levels were quantified by real-time PCR upon stimulation with ephrinB2-FC (eB2) for 72 h in serum-free medium. Untreated MSCs were used as the control. Bars represent means ± SD from 3 biological replicates relative to GAPDH controls; . (b) Protein expression of POSTN was detected using western blotting under the same conditions. (c) The concentration of POSTN in the serum-free medium was assessed by ELISA. Bars represent means ± SD from 3 biological replicates; . (d) The level of phosphorylated EphB4 was detected by ELISA using starved MSCs after stimulation with ephrinB2-Fc (4 μg/mL) for 20 minutes. Fc was used as the control. (e) The efficiency of siRNA and overexpression of EphB4 were evaluated by western blot analysis. MSCs alone were used as the control.

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