Osteoactivin is a novel osteoclastic protein and plays a key role in osteoclast differentiation and activity.
This study presents gene expression, protein expression, and in situ immunohistochemical evidence that osteoclasts express high levels of osteoactivin (OA), which had previously been reported to be an osteoblast-specific protein in bone. OA expression in osteoclasts was up-regulated upon receptor activator of NFkappaB ligand-induced differentiation. Suppression of functional activity of OA with neutralizing antibody reduced cell size, number of nuclei, fusion, and bone resorption activity of osteoclasts. OA was co-immunoprecipitated with integrin beta3 and beta1, indicating that OA co-localizes with integrin beta3 and/or beta1 in a hetero-polymeric complex in osteoclasts. These findings indicate that OA is a novel osteoclastic protein and plays a role in osteoclast differentiation and/or activity.
Sheng
Matilda H-C
MH
Musculoskeletal Disease Center (151), Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA 92357, USA. Matilda.Sheng@va.gov
Wergedal
Jon E
JE
Mohan
Subburaman
S
Lau
K-H William
KH
D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002454:Cell Differentiation / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D047468:Immunoprecipitation; D019012:Integrin beta1 / Q000378:metabolism; D039661:Integrin beta3 / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology* / Q000378:metabolism; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism; D000071681:Tartrate-Resistant Acid Phosphatase
D000906:Antibodies; D005136:Eye Proteins; C445671:Gpnmb protein, mouse; D019012:Integrin beta1; D039661:Integrin beta3; D007527:Isoenzymes; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D053245:RANK Ligand; C505689:Tnfsf11 protein, mouse; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase