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Progelatinase A is produced and activated by rat hepatic stellate cells and promotes their proliferation
Author(s) -
Benyon R. Christopher,
Hovell Christopher J.,
Da Gaça Marianna,
Jones Emma H.,
Iredale John P.,
Arthur Michael J. P.
Publication year - 1999
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.510300431
Subject(s) - gelatinase , gelatinase a , hepatic stellate cell , fibroblast activation protein, alpha , matrix metalloproteinase , microbiology and biotechnology , interstitial collagenase , cell culture , biology , endogeny , procollagen peptidase , concanavalin a , in situ hybridization , fibroblast , in vitro , messenger rna , chemistry , biochemistry , endocrinology , gene , genetics , cancer
Activated hepatic stellate cells (HSCs) are a potential source of gelatinase A, which accumulates in fibrotic livers. Progelatinase A activation requires its binding to a complex of membrane‐type matrix metalloproteinase (MT‐MMP) and tissue inhibitor of metalloproteinases (TIMP)‐2. These studies examine gelatinase A, MT1‐MMP, and TIMP‐2 synthesis by HSCs during activation in vitro and the potential role of gelatinase A in promoting HSC proliferation. Gelatinase A, MT1‐MMP, and TIMP‐2 messenger RNA (mRNA) were all upregulated in HSCs activated on plastic over 5 to 14 days. Gelatinase A expression was maximal at 7 days of culture, coinciding with the peak of HSC proliferation and the onset of procollagen I and α‐smooth muscle actin (α‐SMA) mRNA expression. Active forms of gelatinase A of 62 kd and 66 kd were secreted by activated HSCs and reached a maximum of 12.1% of total enzyme in 14‐day culture supernatants. Treatment of HSCs with concanavalin A (con A) induced activation of MT1‐MMP and enhanced secretion of activated gelatinase A, which reached a maximum of 44.4% of the total enzyme secreted into culture supernatants using 30 μg/mL con A. [ 14 C]‐gelatin degradation assays confirmed the presence of gelatinolytic activity in activated HSC supernatants, which reached a maximum level at 7 days of culture. Antisense oligonucleotide inhibition of endogenous progelatinase A production, or the MMP inhibitor 1,10‐phenanthroline inhibited 3 H‐thymidine incorporation into HSC DNA by greater than 50%. We conclude that HSCs produce progelatinase A during activation in vitro and activate this enzyme coincident with MT1‐MMP and TIMP‐2 synthesis. Gelatinase A activity is required for maximal proliferation of HSCs in vitro suggesting this metalloproteinase is an autocrine proliferation factor for HSCs.