Expression of gelatinases A and B, and TIMPs 1 and 2 during corneal wound healing.
OBJECTIVE
To determine the expression of gelatinases A and B and the localization of tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 during the early stages of corneal wound healing in rats. METHODS. One eye each of 30 adult Sprague-Dawley rats was treated with excimer laser keratectomy; the other eye was untreated. Frozen sections of corneas obtained 6, 18, and 24 hours and 3 and 7 days after wounding were used to perform immunoconfocal microscopy and in situ hybridization.


RESULTS
Gelatinase B was immunolocalized to the basement membrane zone and superficial stroma, and its mRNA was exclusively localized to basal epithelial cells migrating across the wound at 18 and 24 hours and 3 days after wounding. Tissue inhibitor of metalloproteinase-1 was also immunolocalized to the basement membrane zone and superficial stroma at the same time points. Gelatinase A was immunolocalized to the epithelium and stroma of normal corneas and was predominant in the basal epithelium and superficial stroma at 3 and 7 days after wounding. In situ hybridization confirmed gelatinase A expression by the epithelial cells and the stromal keratocytes. Tissue inhibitor of metalloproteinase-2 was immunolocalized to the epithelium in normal and wounded corneas. Intense TIMP-2 labeling of the basement membrane zone was noted 3 days after wounding.


CONCLUSIONS
Unlike gelatinase A, gelatinase B is expressed exclusively by migrating basal epithelial cells after wounding. The matrix metalloproteinase-tissue inhibitor of metalloproteinase (MMP)/TIMP systems may play an important role in the early stages of corneal wound healing after excimer laser keratectomy.
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Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston 02114, USA.
Azar
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D000818:Animals; D017364:Collagenases / Q000235:genetics / Q000378:metabolism*; D003315:Cornea / Q000201:enzymology* / Q000601:surgery; D019084:Fluorescent Antibody Technique, Indirect; D018093:Gelatinases / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D053685:Laser Therapy; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D015347:RNA Probes; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism*; D014945:Wound Healing
D015347:RNA Probes; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D017364:Collagenases; D018093:Gelatinases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9