C. Fernandez-patron et al., Matrix metalloproteinases regulate neutrophil-endothelial cell adhesion through generation of endothelin-1[1-32], FASEB J, 15(12), 2001, pp. 2230-2240
We recently reported that matrix metalloproteinase 2 (MMP-2, gelatinase A)
cleaves big endothelin 1 (ET-1), yielding the vasoactive peptide ET-1[1-32]
. We tested whether ET-1[1-32] could affect the adhesion of human neutrophi
ls to coronary artery endothelial cells (HCAEC). ET-1[1-32] rapidly downreg
ulated the expression of L-selectin and up-regulated expression of CD11b/CD
18 on the neutrophil surface, with EC50 values of 1-3 nM. These actions of
ET-1[1-32] were mediated via ETA receptors and did not require conversion o
f ET-1[1-32] into ET-1 by neutrophil proteases, as revealed by liquid chrom
atography and mass spectroscopy. Moreover, ET-1[1-32] evoked release of neu
trophil gelatinase B, which cleaved big ET-1 to yield ET-1[1-32], thus reve
aling a positive feedback loop for ET-1[1-32] generation. Up-regulation of
CD11b/CD18 expression and gelatinase release was tightly associated with ac
tivation of extracellular signal-regulated kinase (Erk). Stimulation of Erk
activity was due to activation of Ras, Raf-1, and MEK (MAPK kinase). ET-1[
1-32] also produced slight increases in the expression of ICAM-1 and E-sele
ctin on HCAEC, and markedly enhanced beta (2) integrin-dependent adhesion o
f neutrophils to activated HCAEC. These results are the first indication th
at gelatinolytic MMPs via cleavage of big ET-1 to yield ET-1[1-32] activate
neutrophils and promote leukocyte-endothelial cell adhesion and, consequen
tly, neutrophil trafficking into inflamed tissues.