High activity of MMP-2 and MMP-9 in trophoblast tissue during spontaneous abortion

Abstract

Objective: Extracellular matrix degrading enzymes — matrix metalloproteinases are responsible for many aspects of tissue remodelling. Both matrix metalloproteinase type 2 (MMP-2) and matrix metalloproteinase type 9 (MMP-9) are involved in human implantation and placentation. These enzymes play a crucial role in some pathological processes occurring in the early pregnancy. Low activity of MMP-2 and MMP-9 during trophoblast invasion could lead to the development of preeclamsia. Also, the process of spontaneous abortion may be mediated by increased activity of MMP-2 and MMP-9.

Full Text

The aim of the study was the estimation of activity of MMP-2 and MMP-9 in human trophoblast during spontaneous abortion.

Methods: Three specimens of trophoblast from spontaneous abortion at 7^th to 9^th week of pregnancy were obtained. Another 3 specimens of trophoblast were taken after therapeutic abortion at 7^th to 8^th week of pregnancy. Tissues were pulverised, homogenised in buffer containing 10 mM CaCl₂ and 0,25% Triton X-100 and centrifuged at 6000 x g. The supernatants (Triton extracts) were stored at 4° C until further examination. The pellets were resuspended in 50 mM Tris buffer containing 100 mM CaCl₂, 150 mM NaCl and incubated for 6 minutes at 60° C. The samples were centrifuged at 20000 x g and dialysed. The activities of MMP-2 and MMP-9 were estimated by the means of substrate zymography and quantitiated by the integrated computing densitometer system (One.Descan). Statistical analysis was done using Student’s t-test.

Results: The activities of MMP-2 and MMP-9 in Triton extracts were negligible except one case of spontaneous abortion. The estimation of MMP-9 activities in heat extracts revealed statistically significant difference between cases of spontaneous abortion and therapeutic abortion (9,98±7,16 OD vs. 0,77±1,18 OD, p=0,01). Also, the activities of MMP-2 were higher, although not significantly, in spontaneous abortion group (3,46±3,52 OD vs. 0,69±0,92 OD, p=0,09).

Conclusion: MMP-2 and MMP-9 could play important role in the pathophysiology of spontaneous abortion.