Matrix Metalloproteinase 2 Activation in Cultured Corneas

Vol. 33, No. 1, 2001

Free Abstract Article (References) Article (PDF 316 KB)

Original Paper

Matrix Metalloproteinase 2 Activation in Cultured Corneas
Valerie A. Smith, Amro El-Rakhawy, David L. Easty

Division of Ophthalmology, Bristol Eye Hospital, University of Bristol, UK

Address of Corresponding Author

Ophthalmic Res 2001;33:1-6 (DOI: 10.1159/000055634)

Key Words

Matrix metalloproteinase 2 (MMP-2)
Epikeratophakia
Lamellar keratoplasty
Cornea
Corneal stroma

Abstract

Purpose: Corneas that are maintained in tissue culture medium shed their epithelial cells and repopulation following graft surgery is an essential facet of the healing process. Failure to do so may be a result of structural damage to the epithelial basement membrane of a donor cornea. The purpose of the present investigation was to ascertain whether MMP-2, the matrix metalloproteinase produced by corneal keratocytes, may be activated during storage and hence cleave the type IV collagen component of the epithelial cell basement membrane. Methods: Fresh and transplant rejected corneas that had been stored in culture medium for varying time periods and of known donor age were collected. The soluble protein fractions of these corneas were obtained. Their MMP-2 proteins were visualised by zymography on SDS gelatin polyacrylamide gels and assayed for activity against nitrophenyl acetate and denatured [³H]type I collagen. Results: The stromal tissue of fresh, normal corneas produced inactive MMP-2 of M_r 66,000. Although the cultured corneas did not up-regulate MMP-2 production, they contained additional MMP-2 activities of M_r 62,000 and M_r 43,000. The appearance of these additional MMP-2 activities correlated with corneal culture time but not donor age. The ability to cleave denatured [³H]type I collagen correlated with the appearance of the M_r 43,000 activity but not the M_r 62,000 activity. Conclusion: Activated MMP-2 is produced in cultured corneas. For this reason the corneas donated for all graft procedures should not be held in culture medium for periods exceeding 4 weeks.

Author Contacts

Dr. V.A. Smith
Division of Ophthalmology, Bristol Eye Hospital
Lower Maudlin Street
Bristol BS1 2LX (UK)
Tel. +44 117 9284853, Fax +44 117 9251421

Article Information

Received: Received: August 17, 1999
Accepted after revision: December 22, 1999
Number of Print Pages : 6
Number of Figures : 2, Number of Tables : 3, Number of References : 21

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