Metalloproteinases and tissue inhibitors of metalloproteinases in physiologic and complicated pregnancies

Metalloproteinases are a family of endopeptidases that degrade the components of the extracellular matrix (ECM) such as collagen, and thus contribute to the remodelling and the physiological homeostasis of the ECM and its blood supply. The activities of these enzymes are regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and it has been suggested that a balance between MMPs and TIMPs plays an important role in vascular remodelling, angiogenesis and vasodilatation in a number of physiological situations. It follows that, regarding a relationship between MMPs and TIMPs, an imbalance between these molecules may lead to pathology in a wide range of conditions, in particulary during pregnancy where abnormalities in the maternal peripheral vasculature have been proposed as being (partly) responsible for the effects of hypertension on pregnancy and the development of complications including pre-eclampsia and eclampsia.