Abstract
Abstract: :
Purpose: Correlate clinical findings with protein expression patterns in the corneal wound healing response. Methods: Mouse corneas were wounded by partial and total epithelial debridement, and alkali burns. The injured corneas were allowed to heal for various periods of time, 1-84 days. Clinical examinations were performed in vivo using light microscopy and correlated to expression levels of keratin 12, a-smooth muscle actin (a-SMA), keratocan, and collagen. These were analyzed by immunostaining, in situ, northern hybridization with specific antibodies, antisense riboprobes, and 32P-labeled cDNA. Results: Within 3-5 days, K12 positive epithelium resurfaces the partially wounded and alkali burned corneas. The total wounds were resurfaced by conjunctival epithelial cells in 2 weeks. Stromal edema and abnormal epithelium in the total wounds begins to disappear in 6 to 8 weeks. Alkali burn corneas opacify immediately, lasting 2 weeks, and are resurfaced by corneal epithelial cells within 5 days. Stromal edema is greatest in alkali burns and remains up to 4 weeks. Microscopy and histological analyses reveal a large amount of vascularization in the stroma of both the alkali burn and total wound corneas. Myofibroblasts, detected by a-SMA immunostaining, were present in the total wound and alkali burn stromas. The alkali burn stroma undergoes significant contraction by 2 weeks and expresses a high extravascular level of a-SMA. Northern hybridization shows that keratocan expression is downregulated in all wounds and returns to basal levels by 12 weeks in partial and total wounds. Keratocan remains below basal levels at 12 weeks in alkali wounds. Conclusion: More severe corneal injury results in a more dramatic alteration of corneal cell phenotypes.
Keywords: 374 cornea: stroma and keratocytes • 372 cornea: epithelium • 631 wound healing