Main Characteristics and Biological Effects of Martix Metalloproteinases in the Nervous System

Martix metalloproteinases (MMPs), one of the subgroups of the metzincins, are a large family of zinc-dependent endoproteases with multiple roles in extracellular matrix remodelling and modulation of signalling pathways. They are able to cleave all protein components of the extracellular matrix, as well as to activate or inactivate various signaling molecules, such as receptors, growth factors and adhesion molecules. MMPs are associated with many physiological functions such as embryonic development, angiogenesis and wound healing. Therefore, these proteinases are considered to be crucial mediators in many biological processes. Elevated MMP levels have also been implicated in an increasing number of injuries and disorders, such as inflammation, cancer and auto-immune diseases. Recent investigations highlight the beneficial and detrimental effects of MMPs in the nervous system in normal and pathological conditions. This review focuses on the role of MMPs as modulators of fundamental functions in the developing and adult nervous system and their potential to improve repair or regeneration after injury.