Progelatinase A is produced and activated by rat hepatic stellate cells and promotes their proliferation
Progelatinase A is produced and activated by rat hepatic stellate cells and promotes their proliferation
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DOI：
10.1002/hep.510300431
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发表时间：
1999-10-01
期刊：
影响因子：
13.5
通讯作者：
Arthur, MJP
中科院分区：
文献类型：
--
作者：
Benyon, RC;Hovell, CJ;Arthur, MJP
活化的肝星状细胞（HSC）是明胶酶A的潜在来源，明胶酶A在纤维化肝脏中积累。明胶酶A的激活需要其与膜型基质金属蛋白酶（MT-MMP）和金属蛋白酶组织抑制剂（TIMP-2）的复合物结合。本研究检测了体外激活过程中HSC合成明胶酶A、MT 1-MMP和TIMP-2的情况以及明胶酶A在促进HSC增殖中的潜在作用。明胶酶A、MT 1-MMP和TIMP-2信使RNA（mRNA）在5至14天内在塑料上活化的HSC中均上调。明胶酶A的表达在培养7天时达到最大，与HSC增殖的峰值和I型前胶原和α-平滑肌肌动蛋白（α-SMA）mRNA表达的开始相一致。活化的HSC分泌62 kd和66 kd的活性明胶酶A，在培养14天的上清液中达到最大值，占总酶的12.1%。用刀豆球蛋白A（conA）处理HSC诱导MT 1-MMP活化，并增加活化的明胶酶A的分泌，使用30 μ g/mLconA，其达到分泌到培养物上清液中的总酶的最大值44.4%。[C-14]-明胶降解测定证实了活化的HSC上清液中存在明胶分解活性，其在培养7天时达到最大水平。反义寡核苷酸抑制内源性β-半乳糖苷酶A的产生，或MMP抑制剂1，10-菲咯啉抑制H-3-胸苷掺入HSC DNA超过50%。我们的结论是，HSC在体外活化过程中产生明胶酶A，并激活这种酶与MT 1-MMP和TIMP-2的合成一致。明胶酶A活性是体外HSC最大增殖所必需的，表明这种金属蛋白酶是HSC的自分泌增殖因子。
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 alpha-smooth muscle actin (a-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 mu g/mL con A. [C-14]-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 H-3-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.