Emergence of a metalloproteinase / phospholipase A2 axis of systemic inflammation.
We review select aspects of the biology of matrix metalloproteinases (MMPs) with a focus on the modulation of inflammatory responses by MMP-2. MMP-2 is a zinc- and calcium-dependent endoprotease with substrates including extracellular matrix proteins, vasoactive peptides and chemokines. Humans and mice with MMP-2 deficiency exhibit a predominantly inflammatory phenotype. Recent research shows that MMP-2 deficient mice display elevated activity of a secreted phospholipase A2in the heart. Additionally, MMP-2 deficient mice exhibit abnormally high prostaglandin E2levels in various organs (i.e., the heart, brain and liver), signs of inflammation and exacerbated lipopolysaccharide-induced fever. We briefly review the biology of sPLA2enzymes to propose the existence of a heart-centric MMP-2/sPLA2axis of systemic inflammation. Moreover, we postulate that PLA2activation is induced by chemokines, whose ability to signal inflammation is regulated in a tissue-specific fashion by MMPs. Thus, genetic and pharmacologically induced MMP-deficiencies can be expected to perturb PLA2-mediated inflammatory mechanisms.
Department of Biochemistry, Cardiovascular Research Group and Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Carlos
C
Fernandez-Patron
Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Dickson
D
Leung
Chemokines; Inflammation; MMPs; Secreted phospholipase A2