Figure 2.

(A-E) Alkaline phosphatase staining of monolayer cultured human nucleus pulposus (NP) cells from 3 patients and one population of mesenchymal stromal cells (MSCs) maintained with osteogenic medium (B1-B4) and 3 doses of VitD₃ (0.1, 1, and 10 nM; C1-4, D1-4, and E1-4, respectively) in comparison to standard medium (A1-A4) and (F-I) cultured human NP cells from 3 patients exposed to standard and osteogenic medium ± 10 nM VitD₃, all at 21 days. (J) Expression of osteocalcin, osteopontin, and RUNX2 genes (relative to GAPDH) for each culture condition in (F-I). Results show the mean values of NP cells cultured from n = 3 patients with bars representing the standard deviation. Significant differences between osteogenic media with and without VitD₃ are denoted by *P < 0.01.