Abstract
Purpose::
Identify the role of matrix metalloproteinases (MMP-2, MMP-9), and macrophage inflammatory protein -2 (MIP-2) in the pathogenesis of equine fungal keratitis.
Methods::
Paraffin-embedded normal (n=9), purulonecrotic (n=26) and fungal-infected (n=41) corneas were evaluated immunohistochemically for MMP-2, MMP-9 and MIP-2. The number of immunoreactive neutrophils (IN) was counted in 5 high power fields and staining intensity (SI) scored from 1-4. Statistical analysis included chi-square, student’s t-test and linear correlation with significance set at p≤ 0.05.
Results::
The number of IN and (SI) was significantly higher for MIP-2, MMP-2 and MMP-9 for both purulonecrotic and fungal-infected samples than the normal corneas. MIP-2 immunoreactivity was more intense in purulonecrotic samples, than in fungal-infected samples. There was no difference in immunoreactive intensity for MMP-2 or MMP-9 in either group. The number of MIP-2 and MMP-2 IN was significantly higher in purulonecrotic samples than fungal-infected and control samples. There was a positive correlation in the number of IN for MIP-2 and MMP-9 in the purulonecrotic samples, and for MIP-2, MMP-2 and MMP-9 in the fungal-infected samples. There was a positive correlation in (SI) between MIP-2 and MMP-9 for the purulonecrotic samples.
Conclusions::
MIP-2 is responsible for recruiting neutrophils in purulonecrotic keratitis. The expression of MIP-2 is directly proportional to the expression of matrix metalloproteinases MMP-2 and MMP-9 in the fungal affected samples. MMP-2 and MMP-9 appear to play a role in the pathogenesis of equine purulonecrotic keratitis (with and without fungi). Supported by The Veterinary Ophthalmology Research Fund and The Clinical Research Fund - The University of Georgia.
Keywords: cornea: stroma and keratocytes • cornea: epithelium • cornea: basic science