Effect of oncostatin-M on proliferation and activity in osteoblastic MC3T3-E1 cells.
BACKGROUND
Osteogenic cells (osteoprogenitor cells and osteoblasts) respond to specific cytokines, growth factors and hormones. Understanding which cytokines affect osteogenic cells and the consequences of those effects are central to understanding normal and pathologic bone remodeling. Oncostatin-M (OSM) is a glycoprotein interleukin-6 cytokine known to inhibit bone resorption in fetal long bone cultures. However, it is still unclear whether OSM affects bone formation. The aim of this study was to investigate the effects of OSM on bone formation (bone cell proliferation, differentiation and function).


METHODS
For the in vitro bone formation bioassay, MC3T3-E1 cells were plated into 35 mm Petri dishes and cultured in Dulbecco's modified eagle medium (DMEM). Various concentrations (1, 10, 100 or 1,000 units/ml) of OSM were added daily to the experimental dishes, while only DMEM was added in the control dishes during the proliferative and differentiated stages of MC3T3-E1 cell growth. The effect of OSM on bone formation was evaluated using 3H-thymidine incorporation, alkaline phosphatase expression, type I collagen synthesis assay and phase-contrast light microscopy.


RESULTS
OSM significantly decreased osteoprogenitor cell proliferation and alkaline phosphatase activity in a dose-related fashion. There was no effect on type I collagen synthesis noted at any OSM dose. Thus, OSM exerted significant inhibition on bone formation.


CONCLUSIONS
OSM is a potent inhibitor of bone formation by decreasing both osteoprogenitor cell proliferation and alkaline phosphatase activity.
Shih
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C
Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC.
Yen
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CC
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D006131:Growth Inhibitors / Q000494:pharmacology*; D051379:Mice; D053683:Oncostatin M; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D010455:Peptides / Q000494:pharmacology*; D013234:Stem Cells / Q000187:drug effects
D006131:Growth Inhibitors; C508352:Osm protein, mouse; D010455:Peptides; D053683:Oncostatin M; D003094:Collagen; D000469:Alkaline Phosphatase