Fig. 2

Phosphate overload did not induce calcification or osteogenic differentiation. a Von Kossa staining of L6 cells treated for 24, 48, or 72 h with control or high-Pi medium. Magnification = 100×. b Alizarin Red staining of L6 cells treated for 24, 48, or 72 h with control or high-Pi medium. Magnification = 100×. c Effect of high-Pi medium on the expression of bone morphogenetic protein-2 (BMP-2), osteopontin (OPN), osterix (Osx), Pit-1, core-binding-factor α1 (Cbfa1), ALP and matrix GLA protein (MGP) after 24 h. Expression levels were normalized to GAPDH and expressed relative to control medium. *P < 0.05 versus 3 mM at 0 h