Effects of cortisol and bone morphogenetic protein-2 on stromal cell differentiation: correlation with CCAAT-enhancer binding protein expression.
Bone marrow stroma contain pluripotential cells with the potential to differentiate into various mesenchymal cell lineages. We compared the effect of cortisol and bone morphogenetic protein-2 (BMP-2) on the differentiation of murine ST-2 stromal cells into mature osteoblasts or adipocytes. ST-2 cells were cultured for 3-27 days in the presence of 10% fetal bovine serum, 100 microg/mL ascorbic acid, and 5 mmol/L beta-glycerolphosphate in the presence or absence of cortisol at 1 micromol/L or BMP-2 at 1 nmol/L. Untreated ST-2 cells expressed high levels of alkaline phosphatase activity (APA) 15 days after confluence, and this was followed by the appearance of mineralized nodules after 24 days. BMP-2 accelerated and intensified the appearance of cells expressing APA and the presence of mineralized nodules. In contrast, cortisol decreased APA, prevented the formation of mineralized nodules, and induced a cellular phenotype characteristic of adipocytes. Untreated stromal cells expressed osteocalcin, Cbfa1, type I collagen, and alkaline phosphatase mRNA. BMP-2 increased osteocalcin and alkaline phosphatase mRNA, whereas cortisol suppressed their expression, as well as Cbfa1 and type I collagen transcripts. Cortisol enhanced, and BMP-2 downregulated, peroxisome proliferator-activated receptor gamma 2 and adipsin transcripts. The C/EBP transcription factors regulate genes critical for adipocytic and osteoblastic differentiation. Cortisol increased the expression of C/EBP alpha, beta, delta, and gamma mRNA levels, whereas BMP-2 had minor effects on C/EBP expression. In conclusion, BMP-2 accelerates the differentiation of stromal cells toward an osteoblastic phenotype, whereas glucocorticoids induce their differentiation toward an adipocytic phenotype.
Pereira
R C
RC
Department of Research, Saint Francis Hospital and Medical Center, 114 Woodland Street, Hartford, CT 06105-1299, USA.
Delany
A M
AM
Canalis
Ernesto
E
D017667:Adipocytes / Q000166:cytology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D019070:Cell Lineage / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006854:Hydrocortisone / Q000494:pharmacology*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis; D017154:Stromal Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D016212:Transforming Growth Factor beta
D000893:Anti-Inflammatory Agents; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D022762:CCAAT-Enhancer-Binding Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D006854:Hydrocortisone