Matrix metalloproteinases, MMP-7 and MMP-26, in plasma and serum of control and preeclamptic umbilical cord blood

Abstract

Objective Our previous paper 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 (MMPs) are enzymes engaged in degradation of collagen and protein cores of proteoglycans, including those which bind peptide growth factors. Some MMPs, among them matrilysins MMP-7 and MMP-26, participate in activation other members of the MMP family. Study design Studies were performed on the umbilical cord blood taken from 10 control (healthy) newborns and 10 newborns of preeclamptic women. We used Western immunoblotting, immunoenzymatic assay (ELISA) and zymography techniques for detection of matrilysins. The results were submitted to Student's t-test and Mann–Whitney test. Results Umbilical cord blood plasma and serum of control and preeclamptic newborns contained MMP-7 and MMP-26. Both enzymes existed in the form of complexes with other extracellular matrix components and/or their tissue inhibitors in control and preeclamptic subjects. Free latent forms of both matrilysins were observed after the action of reducing agent. Furthermore, we found a distinct increase in the amount of MMP-26 in preeclamptic umbilical cord (UC) blood. No significant differences in MMP-7 content and activity in control and preeclamptic UC blood were observed. Conclusions MMP-7 and MMP-26 could activate MMP-9 by cleavage of some sites in pro-MMP-9. Our results suggest that the high activity of MMP-9 participates in a proteolytic release of peptide growth factors from their complexes with extracellular matrix components, which facilitate their interaction with membrane receptors and stimulate cell division and extracellular matrix synthesis in these cells. It may be one of the mechanisms of extracellular matrix remodelling in the umbilical cord of preeclamptic newborns.