title: The effects of dexamethasone and 1,25-dihydroxyvitamin D3 on osteogenic differentiation of human marrow stromal cells in vitro.
abstract: Effects of dexamethasone and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] were studied in cultures of adult human marrow stromal cells. In primary culture, dexamethasone (10(-8) M) increased the number of fibroblast colonies formed but decreased their average size. The number of colonies expressing alkaline phosphatase activity was increased, consistent with the enhancement of osteogenic differentiation by this glucocorticoid. In secondary culture, osteogenic differentiation was assessed by measurement of the steady-state levels of particular mRNAs that are characteristic of cells of the osteoblast lineage. The mRNAs for alpha 1(I)-procollagen, alkaline phosphatase, osteopontin and bone sialoprotein were expressed under all culture conditions used. In contrast, osteocalcin mRNA expression was detectable only in cultures treated with 1,25(OH)2D3 (10(-8) M). Addition of 1,25(OH)2D3 to control increased the expression of the mRNAs for alkaline phosphatase and osteopontin but had no significant effect on bone sialoprotein expression. The highest levels of expression of the mRNAs for alkaline phosphatase, bone sialoprotein and osteocalcin were observed in dexamethasone-treated cultures to which 1,25(OH)2D3 had been added. These results demonstrate that, as earlier found in other species, dexamethasone and 1,25(OH)2D3 promote the osteogenic differentiation of human marrow stromal cells as measured by expression of these osteogenic markers.
authors.affiliation: Nuffield Department of Orthopaedic Surgery, University of Oxford, England.
authors.forename: J N
authors.initials: JN
authors.lastname: Beresford
authors.forename: C J
authors.initials: CJ
authors.lastname: Joyner
authors.forename: C
authors.initials: C
authors.lastname: Devlin
authors.forename: J T
authors.initials: JT
authors.lastname: Triffitt
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D015152:Blotting, Northern; D001853:Bone Marrow / Q000187:drug effects* / Q000378:metabolism; D001854:Bone Marrow Cells; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology*; D015675:Osteocalcin / Q000096:biosynthesis; D010012:Osteogenesis / Q000187:drug effects*; D053495:Osteopontin; D011347:Procollagen / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis; D012795:Sialoglycoproteins / Q000096:biosynthesis
chemical_list: D011347:Procollagen; D012333:RNA, Messenger; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D015675:Osteocalcin; D053495:Osteopontin; D003907:Dexamethasone; D000469:Alkaline Phosphatase; D002117:Calcitriol