Synergistic effects of 1,25-Dihydroxyvitamin D3 and TGF-β1 on the production of insulin-like growth factor binding protein 3 in human bone marrow stromal cell cultures
Abstract:1,25-Dihydroxyvitamin D3 (calcitriol), transforming growth factor-β (TGF-β), 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-β1 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-β1 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.
Document Type: Research Article
Affiliations: Medical Research Laboratories, Institute of Experimental Clinical Research, University of Aarhus and
Publication date: May 1, 2002