Role of protein kinase A in collagenase-1 gene regulation by prostaglandin E1: studies in a rabbit synoviocyte cell line, HIG-82.
J Bone Miner Res
; 12(4): 561-7, 1997 Apr.
Article
em En
| MEDLINE
| ID: mdl-9101367
ABSTRACT
Gene expression of the matrix-degrading enzyme collagenase-1 in rabbit synoviocytes and human fibroblasts is down-regulated by prostaglandin E1 (PGE1) through a cyclic adenosine monophosphate (cAMP)-dependent pathway. In the current study, we examined the role of protein kinase A (PKA) in the PGE1-mediated effect on collagenase-1 gene expression. Collagenase-1 gene expression was rapidly induced several-fold above control both by a phorbol ester, 12-o-tetradecanoyl phorbol 13 acetate, and interleukin-1 beta (IL-1 beta) in HIG-82 synoviocytes. Treatment with PGE1 and forskolin increased PKA activity in the HIG-82 cells within 15 minutes of adding the stimulating agents. Two inhibitors of PKA, the isoquinoline-sulfonamide derivative, H-89 and a cAMP analog, RpcAMP, blocked the ability of PGE1 to down-regulate collagenase-1 gene expression. However, if PGE1 was added from 6 h to 30 minutes before the PKA inhibitor H-89, collagenase-1 gene expression was inhibited. Constitutive PKA activity was increased in HIG-82 synoviocytes stably transfected with an expression vector pCMV.C alpha that caused the HIG-82 cells to overexpress an active catalytic subunit of PKA. Cells stably transfected with an inactive, mutated C-alpha-variant showed no change in PKA activity. Collagenase-1 mRNA levels in TPA-stimulated cells were reduced to baseline levels in the pCMV.C alpha but not in the mutated C-alpha-transfected cells. These data show the importance of PKA in regulating collagenase-1 gene expression in a synoviocyte cell line.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sulfonamidas
/
Membrana Sinovial
/
Alprostadil
/
Regulação Enzimológica da Expressão Gênica
/
Colagenases
/
Proteínas Quinases Dependentes de AMP Cíclico
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Bone Miner Res
Ano de publicação:
1997
Tipo de documento:
Article