The important role of matrix metalloproteinases in nematode parasites

Matrix metalloproteinases (MMPs) represent a large family of over twenty different secreted or membrane-bound endopeptidases, involved in many physiological (embryogenesis, precursor or stem cell mobilization, tissue remodeling during wound healing, etc.), as well as pathological (inflammation, tumor progression and metastasis in cancer, vascular pathology, etc.) conditions. For a long time, MMPs were considered only for the ability to degrade extracellular matrix (ECM) molecules (e.g., collagen, laminin, fibronectin) and to release hidden epitopes from the ECM. However, expressions of many MMPs have been associated with several pathological conditions. It has been established that the MMPs are conserved throughout the animal kingdom and studies of invertebrate have demonstrated that primarily they are involved in various developing functions in hydra, Drosophila, sea urchin and nematodes. The syntheses of these proteolytic enzymes and their release as excretory and secretory products have been reported in various parasitic nematodes. Host invasion and tissue migration of several nematodes have been linked to the expression and release of parasite-derived proteases. Studies with enzyme inhibitors suggest that the enzyme may be a metalloproteinase. Moreover, substrate impregnated zymographic analysis of extracts and excretory and secretory products of different nematode parasites have revealed the multiple enzyme activities of MMPs with various molecular weights. More research on MMP degradome in nematode parasites can provide valuable information for intense evaluation of pathogenesis caused by these parasites.