Fig. 2

Increased osteogenic differentiation of MSCs preconditioned with LPS plus TNF-α. MSCs were preconditioned with IFN-γ plus TNF-α (I + T, 20 ng/ml each), LPS (20 μg/ml) plus TNF-α (L + T), LPS alone (L), or TNF-α alone (T) for 3 days in growth media, and replaced by osteogenic media for 3 weeks. The osteogenic differentiation ability was examined by ALP activity at week 2 (a) and bone mineralization (Alizarin Red staining) at week 3 (b). *p < 0.05, **p < 0.01, ***p < 0.005. ALP alkaline phosphatase, MSC mesenchymal stem cell