In vivo perimenstrual activation of progelatinase B (proMMP-9) in the human endometrium and its dependence on stromelysin 1 (MMP-3) ex vivo.
Most matrix metalloproteinases (MMPs) are secreted as inactive proenzymes. Their expression is well documented in several human tissues, but their activators in vivo are still unknown. To address this question, the activation of progelatinase B (proMMP-9) in the human endometrium was selected as a model system. ProMMP-9 was detected by gelatin zymography in homogenates of fresh endometrial tissue sampled during all phases of the menstrual cycle, whereas its active form was observed only during the late secretory and menstrual phases. Furthermore, proMMP-9 was expressed and activated in endometrial explants sampled outside the perimenstrual phase and cultured in the absence of both progesterone and oestradiol, mimicking the menstrual condition in vivo. Analysis of such tissue cultures by gelatin zymography and Western blotting showed that activation of proMMP-9 depended on a secreted factor and was selectively inhibited by either a synthetic inhibitor of stromelysin 1 (MMP-3) or a monoclonal antibody that specifically blocks MMP-3, thus providing strong evidence for the activation of proMMP-9 in vivo by MMP-3. The activation of proMMP-3 was itself inhibited by a broad-range MMP inhibitor in most cultures, but seemed to involve multiple pathways, implying both serine proteinases and metalloproteinases, which could operate in parallel or sequentially.
Rigot
V
V
Cell Biology Unit, Institute of Cellular Pathology, Université catholique de Louvain, avenue Hippocrate, 75, B-1200 Bruxelles, Belgium.
Marbaix
E
E
Lemoine
P
P
Courtoy
P J
PJ
Eeckhout
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015153:Blotting, Western; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D018093:Gelatinases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D006801:Humans; D019278:Matrix Metalloproteinase 3 / Q000096:biosynthesis / Q000737:chemistry*; D061965:Matrix Metalloproteinase Inhibitors; D008597:Menstrual Cycle; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D051379:Mice; D011374:Progesterone / Q000378:metabolism; D011485:Protein Binding; D013997:Time Factors
D000911:Antibodies, Monoclonal; D004791:Enzyme Inhibitors; D004792:Enzyme Precursors; D061965:Matrix Metalloproteinase Inhibitors; D011374:Progesterone; D004958:Estradiol; D018093:Gelatinases; D008666:Metalloendopeptidases; C069860:progelatinase; D019278:Matrix Metalloproteinase 3