Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1995-7-5
pubmed:abstractText
In addition to inhibiting the proteolytic activity of the matrix metalloproteinases, tissue inhibitors of metalloproteinases (TIMPs) promote the growth of cells in the absence of other exogenous growth factors. TIMP-2 stimulates the proliferation of fibrosarcoma (HT-1080) cells and normal dermal fibroblasts (Hs68) in a dose-dependent manner. This response is evident as early as 2 h and persists up to 48 h after treatment with recombinant TIMP-2 (rTIMP-2). The specificity of this response is demonstrated by the ability of affinity-purified polyclonal anti-TIMP-2 antibodies to ablate TIMP-2 mitogenesis and by the lack of response to TIMP-1. This response is also blocked by the presence of an adenylate cyclase inhibitor, 9-(tetrahydro-2-furyl)adenine (SQ22536). Although SQ22536 did not affect untreated fibroblasts or fibrosarcoma cells, this inhibitor completely abrogates the proliferative response induced by rTIMP-2. Treatment of these cells with rTIMP-2 also stimulates the production of cAMP in a time-dependent manner that differs for the two cell lines. Moreover, treatment of purified cell membranes with rTIMP-2 suppresses cholera toxin-mediated ADP-ribosylation of the GTP-binding protein, Gs alpha subunit. These results indicate that the alpha beta gamma heterotrimer is dissociated by treatment with rTIMP-2, which may facilitate the Gs alpha-mediated activation of adenylate cyclase and subsequent production of cAMP. Since cAMP binds to the regulatory subunit of cAMP-dependent protein kinase and activates kinase activity, we evaluated how treatment with rTIMP-2 affected both these parameters. We demonstrate in this report that the cAMP produced in response to treatment with rTIMP-2 binds to the type I regulatory subunit of cAMP-dependent protein kinase and stimulates kinase activity. These results are the first demonstration that TIMP-2 directly activates adenylate cyclase to produce cAMP, which increases cAMP-dependent protein kinase activity, resulting in stimulation of fibroblast mitogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13453-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Tissue inhibitor of metalloproteinase-2 stimulates fibroblast proliferation via a cAMP-dependent mechanism.
pubmed:affiliation
Extracellular Matrix Pathology Section, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article