Three-dimensional collagen matrices induce delayed but sustained activation of gelatinase A in human endothelial cells via MT1-MMP.
Gelatinase A, a member of the matrix metalloproteinase (MMP) family, plays an important role during angiogenesis. It is constitutively expressed by human endothelial cells as a latent enzyme and requires activation. Thrombin is the only described physiological inducer of gelatinase A in human endothelial cells. In this study, we investigated the mechanisms of gelatinase A activation by another physiological inducer, collagen. Endothelial cells were cultured on various ECM components for 24 h and the conditioned media were assessed for gelatinase A activity using gelatin zymography. The results demonstrated that type I collagen matrix specifically activates gelatinase A after 24 h in human umbilical vein and 48 h in neonatal foreskin endothelial cells. In contrast, thrombin activated gelatinase A after only 2 h. Activation by collagen was sustained over long periods of time in culture (96 h). Unlike thrombin-induced activation, collagen required active membrane type 1-MMP (MT1-MMP) on the endothelial cell surface to activate gelatinase A. In addition, collagen-induced activation of gelatinase A was inhibited by antibodies to the integrin receptor, alpha(2)beta(1), but not alpha(3)beta(1). Our findings, that collagen can provide long-term activation of gelatinase A are likely to be relevant to endothelial cell invasion during angiogenesis.
Nguyen
M
M
Sutton Arthritis Research Laboratory, Royal North Shore Hospital, St Leonards, Australia.
Arkell
J
J
Jackson
C J
CJ
D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004789:Enzyme Activation; D006801:Humans; D016023:Integrins / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism*; D038981:Receptors, Collagen; D013997:Time Factors
D016023:Integrins; D038981:Receptors, Collagen; D003094:Collagen; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2