Matrix metalloproteinase-7 of the umbilical cord in preeclampsia

Our previous papers demonstrated that preeclampsia – associated accumulation of collagen and proteoglycans in the umbilical cord tissues is a result of increased biosynthesis and decreased degradation of these components. Metalloproteinases are enzymes engaged in degradation of collagen and protein cores of proteoglycans, including those which bind peptide growth factors. Western Immunoblot method, immunoenzymatic assay (ELISA) and zymographic technique were used. The umbilical cord arteries, umbilical cord vein and Wharton’s jelly of control and preeclamptic newborns contained MMP-7. Free form of this enzyme was detected in both vessel wall extracts. High molecular weigh components containing MMP-7 were detected in all umbilical cord tissues. Preeclampsia is accompanied by a significant increase of MMP-7 content in both vessel walls. No significant differences between control and preeclamptic Wharton’s jelly were found. MMP-7 could activate MMP-9 by their cleavage sites in pro-MMP-9. The high activity of MMP-9 participates in a proteolytic release of peptide growth factors from their complexes with other extracellular matrix components, which facilitate their interaction with membrane receptors and stimulate cell division and extracellular matrix biosynthesis in these cells. It may be one of the mechanism of extracellular matrix remodeling in the umbilical cord of preeclamptic newborns.