Osteoblast differentiation of human bone marrow cells under continuous and discontinuous treatment with dexamethasone.
Dexamethasone (Dex) has been shown to induce osteoblast differentiation in several cell culture systems. This study investigated the effect of continuous and discontinuous treatment with Dex on osteoblast differentiation of human bone marrow stromal cells (BMSC). Primary culture and first passage were cultured in media with or without Dex 10(-7) M. During the culture period, cells were incubated at 37 degrees C in humidified atmosphere of 5% CO2 and 95% air. At 7, 14, and 21 days, cell proliferation, cell viability, total protein content, alkaline phosphatase (ALP) activity and bone-like formation were evaluated. Data were compared by two-way analysis of variance. Dex did not affect cell viability and total protein content, but reduced cell number. ALP activity and bone-like formation increased when only first passage or both primary culture and first passage were treated with Dex, in comparison to the groups that did not have contact with Dex after first passage. The results of this study indicate that, for human BMSC, continuous presence of Dex did not appear to be required for development of the osteoblast phenotype, but Dex must be present after first passage to allow osteoblast differentiation expressed by reduced cell proliferation and increased ALP activity and bone-like formation.
Department of Oral and Maxillofacial Surgery and Periodontology, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.
Márcio Mateus
MM
Beloti
Adalberto Luiz
AL
Rosa
D000469:Alkaline Phosphatase / Q000032:analysis; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D010641:Phenotype; D011506:Proteins / Q000032:analysis; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D011506:Proteins; D003907:Dexamethasone; D000469:Alkaline Phosphatase