Peroxisome proliferator-activated receptor activators modulate the osteoblastic maturation of MC3T3-E1 preosteoblasts

The reduced bone mineral density (BMD) observed in osteoporosis results, in part, from reduced activity of bone-forming osteoblasts, We examined the e ffect of peroxisome proliferator-activated receptor (PPAR) activators on MC 3T3-E1 preosteoblast maturation. Activators of PPAR alpha, delta and gamma induced alkaline phosphatase activity, matrix calcification and the express ion of osteoblast genes as determined by reverse transcriptase-polymerase c hain reaction, Howe, er, at relatively high concentrations of the specific PPAR gamma ligands, ciglitazone and troglitazone, maturation was inhibited. PPAR alpha, delta and gamma 1 were expressed in MC3T3-E1 cells. PPAR gamma 1 mRNA and protein levels were induced early during osteoblastic maturatio n, We speculate that endogenous and pharmacological PPAR activators mag aff ect BMD by modulating osteoblastic maturation. (C) 2000 Federation of Europ ean Biochemical Societies.