Pre-eclampsia (EPH-gestosis)-induced decrease of MMP-s content in the umbilical cord artery

Abstract

Background: It was found in our previous paper that pre-eclampsia-associated accumulation of collagen in the umbilical cord artery (UCA) is a result of increased biosynthesis and decreased degradation of this protein. It is known that the activity of collagenolytic enzymes is a main factor regulating collagen degradation rate in various tissues. Methods: For this reason it was decided to evaluate the effect of pre-eclampsia on the content and activity of metalloproteinases by immunoenzymatic method (ELISA), zymographic technique and with the use of specific substrates. Results: A low amount of MMP-1 (collagenase 1), MMP-9 (gelatinase B) and MMP-3 (stromelysin 1) was detected in the extracts from the wall of the umbilical cord artery. MMP-2 (gelatinase A) is the main collagenolytic enzyme in UCA wall (both latent and active form). Pre-eclampsia is associated with a distinct reduction in those metalloproteinases content in comparison to control UCAs. It can be concluded from zymography that MMP-2 (gelatinase A) of the umbilical cord artery forms an inactive complex with a tissue inhibitor of metalloproteinases (TIMP). Such a complex dissociates under the action of p-aminophenylmercuric acetate (APMA) or sodium dodecyl sulphate. Conclusions: The decrease of metalloproteinases content and activity in the umbilical cord artery may be a factor that reduces the breakdown of collagen in the arterial wall and promotes the accumulation of this protein. The accumulation of collagen with simultaneous reduction in elastin content in the UCA may be the factor that reduces the elasticity of arterial wall and decreases the blood flow in the fetus of women with pre-eclampsia.