Figure 4

Cytokine-mediated suppression of osteogenesis was not reversed by modulation of the nuclear factor-kappa-B (NF-κB) pathway. Negative controls consisted of mesenchymal stem cells (MSCs) cultured in complete expansion medium, and positive controls represent MSCs stimulated to undergo osteogenesis, MSCs transduced with a super-repressor inhibitor of NF-κB (AdsrIκB) before differentiation, and MSCs differentiated in the presence of curcumin at a concentration of 25 μM (CQ 25). Osteogenesis was suppressed in (A) BALB/c and (B) FVB MSCs by 10 ng/mL tumor necrosis factor-alpha (TNFα) and interleukin-1-beta (IL-1β) compared with controls and was not rescued by MSC transduction with AdsrIκB or by the addition of curcumin at 10 μM (CQ 10) or 25 μM. The suppression of osteogenesis of BALB/c MSCs, irrespective of transduction with AdsrIκB, was also demonstrated by alizarin red staining (C). Data shown are mean calcium per well ± standard error of the mean of triplicate experiments. *P <0.05, **P <0.001 (two-way analysis of variance).