Matrix metalloproteinases in destructive lung disease

•MMPs contribute to elastin and collagen fiber degradation, both hallmarks of pulmonary emphysema.•Degradation products of both collagen and elastin function as chemoattractants•Evidence supporting a pathophysiologic role for an MMP in emphysema is the strongest for MMP12.

Matrix metalloproteinases (MMPs) play essential physiologic roles in numerous processes ranging from development to wound repair. Unfortunately, given the broad substrate specificity of the MMP family as a whole, aberrant degradation of extracellular matrix proteins can result in destructive disease. Emphysema, the result of destroyed lung elastin and collagen matrix, is the prototypical example of such a destructive process. More recent data has highlighted that MMPs play much more elaborate physiologic and pathophysiologic roles than simple matrix protein cleavage. Key pathophysiological roles for MMPs in emphysema will be discussed herein.