Role of gelatinases MMP-2 and MMP-9 in tissue remodeling following acute lung injury

Acute lung injury is characterized by a severe disruption of alveolo-capill ary structures and includes a variety of changes in lung cell populations. Evidence suggests the occurrence of rupture of the basement membranes and i nterstitial matrix remodeling during acute lung injury. The dynamic equilib rium of the extracellular matrix (ECM) under physiological conditions is a consequence of the balance between the regulation of synthesis and degradat ion of ECM components. Matrix metalloproteinases (MMPs) represent a group o f enzymes involved in the degradation of most of the components of the ECM and therefore participate in tissue remodeling associated with pathological situations such as acute lung injury. MMP activity is regulated by proteol ytic activation of the latent secreted proenzyme and by interaction with sp ecific tissue inhibitors of metalloproteinases, This review details our kno wledge of the involvement of MMPs, namely MMP-2 and MMP-9, in acute lung in jury and acute respiratory distress syndrome.