Synergistic effects of 1,25-Dihydroxyvitamin D3 and TGF-beta1 on the production of insulin-like growth factor binding protein 3 in human bone marrow stromal cell cultures.
1,25-Dihydroxyvitamin D3 (calcitriol), transforming growth factor-beta (TGF-beta), and insulin-like growth factors (IGFs) are all important bone regulatory factors known to affect proliferation and differentiation of human bone-forming cells (osteoblasts). We have previously shown that TGF-beta1 increased IGF-I and IGF-binding protein (IGFBP)-3 production in human bone marrow stromal (hMS) osteoblast progenitors and calcitriol stimulated IGFBP-3 and IGFBP-4 production. As interaction between signaling pathways of these factors has been reported, the present study aimed at examining the concerted actions on components of the IGF-system. We report that co-treatment with TGF-beta1 and calcitriol resulted in a synergistic increase in IGFBP-3 production, thereby suggesting that the effects of these factors on hMS osteoblast differentiation may involve the observed increase in IGFBP-3.
Kveiborg
M
M
University Department of Endocrinology and Metabolism, Aarhus Amtssygehus, Denmark. marie.kveiborg@yale.edu
Flyvbjerg
A
A
Kassem
M
M
D000328:Adult; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism*; D002117:Calcitriol / Q000494:pharmacology*; D018076:DNA, Complementary / Q000737:chemistry; D004357:Drug Synergism; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000096:biosynthesis*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D018076:DNA, Complementary; D018972:Insulin-Like Growth Factor Binding Protein 3; D016212:Transforming Growth Factor beta; D012313:RNA; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D002117:Calcitriol