Dexamethasone regulation of marrow stromal-derived osteoblastic cells.
The clonal subtypes of cells in the osteogenic family represented by fibroblastoid MBA-15.33, preosteoblast MBA-15.4, and mature osteoblastic MBA-15.6 cells were used to study the effects of glucocorticoid (dexamethasone). The role of dexamethasone was monitored on cell attachment when plated on various protein substrata (BSA, collagen 1, and Matrigel). A 24 h exposure of the cells to 10(-6) M or 10(-7) M dexamethasone differential affects their attachment preference. MBA-15.33 and MBA-15.4 cells increased their attachment capability on collagen 1, while MBA-15.6 cells' attachment was inhibited. Pretreatment with (10(-6) M) dexamethasone caused an increase in attachment on Matrigel by MBA-15.33 cells and to less extent by MBA-15.4 cells. Additionally, measurements of two enzymatic activities were monitored; one is alkaline phosphatase (ALK-P), and the second is neutral endopeptidase (CD10/NEP). MBA-15.33, MBA-15.4, and MBA-15.6 cells were exposed to dexamethasone or to various growth factors (bone morphogenic protein (BMP-2 and BMP-3), TGF beta, and IGF-1). In some experiments, pretreatment of cells by dexamethasone was followed by exposure to the growth factors. The cells' challenged cellular responses were not uniform and revealed a differential pattern when their ALK-P and CD10/NEP enzymatic activities were measured.
Department of Cell Biology and Histology, Sackler School of Medicine, Tel Aviv University, Israel.
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Fried
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Benayahu
D000818:Animals; D001854:Bone Marrow Cells; D055396:Bone Morphogenetic Protein 2; D055398:Bone Morphogenetic Protein 3; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology
C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D055398:Bone Morphogenetic Protein 3; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D003907:Dexamethasone