1,25-dihydroxyvitamin D3 potentiates fluoride-stimulated collagen type I production in cultures of human bone marrow stromal osteoblast-like cells.

In this study we tested the effects of sodium fluoride (NaF) in serum-free cultures of human marrow stromal osteoblast-like [hMS(OB)] cells. NaF (10(-5) M) stimulated hMS(OB) cell proliferation up to 220% of control cultures. NaF alone did not increase type I collagen production, but in the presence of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] (10(-9) M), NaF enhanced type I collagen production in a dose-dependent way to 300% of 1,25-(OH)2D3-treated control cultures. The production of alkaline phosphatase (ALP) and osteocalcin (bone gla protein, BGP) was also enhanced in the presence of 1,25-(OH)2D3 to 170 and 200%, respectively, of 1,25-(OH)2D3-treated controls. Our results suggest that 1,25-(OH)2D3 potentiates fluoride-mediated anabolism in hMS(OB) cell cultures and suggest that osteoblast precursors in bone marrow are targets for fluoride action.