Expression of fibronectin isoforms bearing the alternatively spliced EIIIA, EIIIB, and V segments in corneal alkali burn and keratectomy wound models in the rat

Katerina Havrlikova, Mei Mellott, Adam H. Kaufman, Grace A. Loredo, John H. Peters, Robert B. Colvin, C. Stephen Foster

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Purpose: To better understand the healing process in the wounded cornea, fibronectin (FN) isofonns bearing the alternatively spliced EIIIA, EIIIB, and V segments (EIIIA-, EIIIB+, and V+ FNs) were evaluated in alkali burn and keratectomy wound models in the rat. Methods: Alkali burn or keratectomy wounds (both 2 mm) were created, and corneas were harvested at various time points and analyzed by indirect immunofluorescence using antibodies specific for the EIIIA, EIIIB, and V segments as well as for the total pool of FN (total FN). Results: There was minimal staining for any variety of FN in the epithelium or basement membrane zone (BMZ) in normal cornea, but each antibody produced granular staining in the stroma. Bright staining for V+ and total FNs was evident at the denuded stromal surface 1 day following keratectomy. In contrast, staining for EIIIA+ and EIIIB+ FNs was negligible at 24 hours but appeared on the wound surface under the migrating unstained epithelium by the second day. BMZ staining for FN then gradually subsided, such that there was little or no staining by 6 weeks. In contrast, alkali burn wounds exhibited very little BMZ staining throughout the time course. Although there was preferential staining of the anterior aspect of Descemet membrane by anti-EIIIA and anti-EIIIB antibodies under normal conditions, the staining intensity of the anterior and posterior aspects became similar following corneal wounding. Conclusion: Deposition of EIIIA- and EIIIB+ FNs in the BMZ of the keratectomy wound occurs more slowly than deposition of V+ and total FNs. EIIIA + FN is expressed in a distribution that overlaps with that previously described for the α9 integrin subunit following corneal debridement, suggesting that EIIIA-α9 interactions could occur during corneal wound healing. In contrast, the relative lack of FN deposition in alkali burn wounds suggests that proteolytic degradation of FN may occur; and this, along with impairment of new FN synthesis because of cellular damage, could play a role in the high prevalence of recurrent epithelial erosions in alkali-wounded corneas.

Original languageEnglish (US)
Pages (from-to)812-818
Number of pages7
JournalCornea
Volume23
Issue number8
DOIs
StatePublished - Nov 2004
Externally publishedYes

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Keywords

  • Alkali burn
  • Fibronectin
  • Keratectomy

ASJC Scopus subject areas

  • Ophthalmology

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