Tissue inhibitor of metalloproteinase-I and interstitial collagenase expression in XXXX and activated @entity1 hepatic lipocytes.

@entity1 @entity82 @entity5 @entity8652 @entity2533 @entity3619
1. Activated hepatic lipocytes are central to the pathogenesis of liver @entity82 as the principal source of both interstitial collagens and matrix-degrading metalloproteinases. In progressive @entity82 there is a failure to degrade interstitial collagens with a reported decrease in collagenase activity. In these studies we investigate expression of the potent collagenase inhibitor, tissue inhibitor of metalloproteinase-1, and interstitial collagenase in end-stage @entity3619 and activated @entity1 hepatic lipocytes in culture. 2. Messenger RNA transcripts for interstitial collagenase and tissue inhibitor of metalloproteinase-1 in explanted @entity1 liver were quantified by ribonuclease protection assay and densitometric analysis. This indicated that tissue inhibitor of metalloproteinase-1 and interstitial collagenase expression in @entity3619 were also coordinately up-regulated. 3. Using Northern analysis of RNA from @entity1 lipocytes in primary culture on plastic, mRNA for interstitial collagenase could not be detected in unstimulated cells but was present after stimulation with @entity5 factor alpha. Tissue inhibitor of metalloproteinase-1 mRNA was present in unstimulated lipocytes and up-regulated fivefold in response to @entity5 factor alpha. Using activity assay of serum-free conditioned media, interstitial collagenase could not be detected in unstimulated primary cultures, primary cultures stimulated with @entity5 factor alpha or @entity2533 (n = 3 and n = 4 respectively) or in passaged lipocytes (n = 6). In contrast, free tissue inhibitor of metalloproteinase-1 activity was present in unstimulated and passaged cultures and this was increased in response to @entity5 factor alpha and transforming growth factor @entity8652 .(ABSTRACT TRUNCATED AT 250 WORDS)
