Figure 4.

Specific gene expression levels in MSCs under chondrogenic conditions. Gene expression analyses of human synovial MSCs overexpressing IGF-1 after induction of chondrogenic differentiation were performed using real-time RT-PCR. The MSCs were transduced with a pLVSIN-IRES-ZsGreen1 (control; left) or the pLVSIN-IRES-IGF-1 ZsGreen vector (IGF-1; right) and cultured in a chondrogenic differentiation medium for 14 days. The values for each gene were normalized to the GAPDH house keeping gene levels used as the internal control. Ct values were generated for each target gene. ^∗Statistically significant compared with control values (p < 0.05). GAPDH: glyceraldehyde-3-phosphate dehydrogenase. Col2 (type II collagen alpha1) and Sox9 were assessed as chondrogenic markers. Col10 (type X collagen) and MMP-13 (matrix metalloproteinase 13) were assessed as hypertrophic chondrocyte markers. ALP (alkaline phosphatase) and Osterix were assessed as osteogenic markers.