Mechanotransduction in stretched osteocytes--temporal expression of immediate early and other genes.
Biochem Biophys Res Commun
; 246(2): 404-8, 1998 May 19.
Article
en En
| MEDLINE
| ID: mdl-9610372
ABSTRACT
Osteocytes, dendritic bone cells, transduce signals of mechanical loading that results in bone formation. We have reported in stretched primary osteocytes that the cAMP level, IGF-I and osteocalcin protein levels were elevated (Endocrinology 1372028, 1996). Here we report that stretching induces the expression of immediate early genes, c-fos, and COX-2; inducive cyclooxygenase gene. Compared to c-fos, COX-2 as well as IGF-I and osteocalcin mRNA appeared in a biphasic manner; second peaks at 8 (COX-2) or 24 hrs (IGF-I and osteocalcin) later. Furthermore, these second peaks are abolished by including NS398, a specific inhibitor of the inducive cyclooxygenase, during the 3-hr stretching. A sequence that the calcium influx activates PkA which, in turn, activates c-fos and COX-2 transcription resulting in the production of proteins such as IGF-I and osteocalcin. A long-lasting effect of mechanical loading in vivo can be explained from the secondary anabolic reaction we observed through the upregulated COX-2 mRNA.
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Banco de datos:
MEDLINE
Asunto principal:
Osteocitos
/
Genes Inmediatos-Precoces
Límite:
Animals
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
1998
Tipo del documento:
Article
País de afiliación:
Japón