Expression of vacuolar H(+)-ATPase in mouse osteoclasts during in vitro differentiation.
Osteoclasts express high levels of a vacuolar H(+)-adenosinetriphosphatase (H(+)-ATPase) on the ruffled membrane which they employ to dissolve bone mineral by acidifying their site of attachment on bone. The factors that control amplification of H(+)-ATPase during osteoclast differentiation are poorly understood. We examined the expression of vacuolar H(+)-ATPase in a cell culture system in which mouse spleen cells can be induced to differentiate into osteoclasts by coculture with a mouse bone marrow stromal cell line. We found that the coculture system produced active osteoclasts, identified as multinucleated cells with staining for tartrate-resistant acid phosphatase activity that formed genuine resorption pits in bone. These cells developed high levels of H(+)-ATPase expression in culture, and omission of dexamethasone or 1 alpha,25-dihydroxyvitamin D3 from the coculture system each partially suppressed the expression of H(+)-ATPase. The results demonstrate that the spleen and PA6 cell coculture system may be useful for investigating the factors that control the induction of H(+)-ATPase amplification that occurs during osteoclast differentiation.
Wang
Z Q
ZQ
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Hemken
P
P
Menton
D
D
Gluck
S
S
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption; D002454:Cell Differentiation; D002478:Cells, Cultured; D003584:Cytological Techniques; D003907:Dexamethasone / Q000494:pharmacology; D004100:Dihydroxycholecalciferols / Q000494:pharmacology; D004351:Drug Resistance; D005819:Genetic Markers; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010010:Osteoclasts / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D010641:Phenotype; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D013154:Spleen / Q000166:cytology; D013644:Tartrates / Q000494:pharmacology; D014617:Vacuoles / Q000201:enzymology*
D004100:Dihydroxycholecalciferols; D005819:Genetic Markers; D013644:Tartrates; D003907:Dexamethasone; D000135:Acid Phosphatase; D006180:Proton-Translocating ATPases; C029768:tartaric acid