Matrix metalloproteinases in a murine model of corneal injury and fungal keratitis.

Abstract

Abstract: : Purpose:To determine the kinetics of gelatinase expression (MMP–2 and MMP–9) in a mouse model of corneal trauma and Fusarium solani keratitis. Methods:Corneas of immunocompetent and cyclophosphamide–treated BALB/c mice were scarified and either inoculated with 10⁵ culturable units of a human corneal isolate of Fusarium solani or mock inoculated with phosphate–buffered saline. The animals were sacrificed at 1.5 hours, 1 day, 4 days and 8 days post–scarification. The eyes were enucleated and homogenized. MMP–2 and MMP–9 were detected by gelatin zymography (n=10/group/timepoint). Non–scarified eyes served as controls. The results were compared to the fungal infection and disease outcome. Results: Gelatin zymography demonstrated that eye trauma caused by superficial corneal scarification and by Fusarium infection induced expression of both MMP–2 and MMP–9 at the protein level. The absolute level of MMP–2 and MMP–9 expression varied kinetically as well as the relative amounts of each proteinase. While cyclophosphamide treatment affected the Fusarium infection as well as the progression and severity of corneal disease, no significant overall affects were observed on MMP expression. Conclusions:Corneal trauma due to direct wounding or Fusarium infection results in up–regulation of MMP–2 and MMP–9. Our results are consistent with findings for other corneal pathogens and suggest a potential role for these enzymes in the pathogenesis of experimental Fusarium keratitis.

Keywords: fungal disease • keratitis • wound healing