Expression of integrins and MMPs during alkaline-burn-induced corneal angiogenesis.
OBJECTIVE
To determine in a corneal alkaline burn model of angiogenesis whether the expression of integrins and MMPs is consistent with a VEGF-induced angiogenic response.


METHODS
Neovascularization in female Sprague-Dawley rats was induced by alkaline cauterization of the central cornea. RT-PCR for integrins alpha(1), alpha(2), beta(3), and beta(5); the endothelial marker CD31; and metalloproteinases MMP-2 and MT1-MMP was performed on naive corneas and on cauterized corneas 72 and 288 hours after cautery. Analyses of protein and MMP expression were conducted on naive corneas and on cauterized corneas 24, 72, 120, and 168 hours after cautery by immunofluorescence microscopy and gelatin zymography.


RESULTS
RT-PCR indicated a correlation between the induced angiogenic response and the expression of alpha(1) and beta(3) integrin subunits and MT1-MMP. Immunohistochemical analysis indicated that alpha(1), alpha(2), alpha(5), and beta(5) integrins and MMP-2 and MT1-MMP were expressed on the newly developing vasculature. The beta(3) integrin was preferentially expressed on platelets.


CONCLUSIONS
Integrin expression during neovascularization of rat corneas in response to alkaline injury correlates with an angiogenic response that uses the VEGF/alpha(v)beta(5) pathway. MMP-2 and MT1-MMP, but not MMP-9, are expressed in a pattern consistent with their involvement in the angiogenic response.
Zhang
Heying
H
Medimmune, Gaithersburg, Maryland, USA.
Li
Chen
C
Baciu
Peter C
PC
D000468:Alkalies; D000818:Animals; D002057:Burns, Chemical / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D003315:Cornea / Q000098:blood supply* / Q000473:pathology; D065306:Corneal Injuries; D016510:Corneal Neovascularization / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D005126:Eye Burns / Q000139:chemically induced*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000468:Alkalies; D016023:Integrins; D012333:RNA, Messenger; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2