Figure 7.

EpEX enhances MSC bone formation by up-regulating RUNX2. A, MSCs were treated with EpEX for 14 days during osteo-induction. Calcium precipitation was measured by ARS staining to probe the efficiency of osteogenesis. This method shows higher calcium precipitation in EpEX (day 14)-treated cells than nontreated controls. B, quantification of osteogenesis, as measured by ARS staining, is shown for each group. C, MSCs were induced by osteogenetic medium and treated with EpEX at indicated doses. The gene expression of RUNX2 was examined by qPCR. D, MSCs were pretreated with let-7 mimetic and then treated with EpEX for 14 days during osteo-induction. ARS staining was performed to check the efficiency of osteogenesis. E, MSCs were pretreated with let-7 inhibitor and then treated with EpEX for 14 days during osteo-induction. ARS staining was performed to check the efficiency of osteogenesis. F, MSCs were pretreated with let-7 mimetic and then induced by EpEX. RUNX2 gene expression was measured by qPCR. G, MSCs were pretreated with let-7 inhibitor and induced by EpEX. RUNX2 gene expression was examined by qPCR. H, MSCs were treated with 0 or 5 μm RUNX2 inhibitor RXM and then treated with EpEX (3 μg/ml) for 21 days during osteo-induction. Calcium precipitation was measured by ARS staining to probe the efficiency of osteogenesis (left panel). The quantification results of the ARS staining are shown in the right panel. Data represent the mean ± S.D. *, p < 0.05, compared with control without RXM and EpEX group.