Figure 1.

(A-H) Alkaline phosphatase staining of cultured mesenchymal stromal cells (MSCs) and human nucleus pulposus (NP) cells maintained in monolayer for 21 days with osteogenic medium (osteo) (B1-B4) and its components, dexamethasone (DEX) (C1-C4), β-glycerophosphate (B-G) (D1-D4), l-ascorbic acid-2-phosphate (AA) (E1-E4) and in combination (F1-H4), in comparison with the control of “standard” medium (A1-A4). (I) Expression of osteocalcin, osteopontin, and RUNX2 genes (relative to GAPDH) for each corresponding culture condition at 21 days. Results show the mean values of NP cell cultures from 3 different patients and the bar represents the standard deviation. Significant differences are denoted by *P < 0.05 and **P < 0.005.