FIG. 4.

HGF/c-Met signaling alters the osteogenic and chondrogenic differentiation capacity of MSC, but not their adipogenic differentiation potential. MSC were cultured in the commercial differentiation medium to stimulate differentiation along adipogenic, osteogenic, and chondrogenic lineages. (a) Adipogenic cultures were stained with Oil Red O, showing no differences between c-Met KD MSC and SCR MSC in their adipogenic differentiation capacity. (b) Alizarin Red S staining of calcium deposits revealed a decrease of osteogenic differentiation in KD MSC compared to SCR MSC and untransduced MSC. (c) Safranin O staining of chondrogenic pellets demonstrated a decrease in chondrogenic differentiation potential in KD MSC compared to SCR MSC and untransduced MSC. Notably, the level of differentiation of SCR MSC in all three differentiation assays was comparable to the untransduced MSC. Shown are representative images of 5–7 replicates of osteogenic and adipogenic cultures performed in three separate experiments. The chondrogenic assays were performed as three independent replicates.