Abstract
Abstract: :
Purpose: Pseudomonas aeruginosa keratitis has very rapid and destructive clinical courses and often leads to the corneal perforation. The immune responses against Pseudomonas aeruginosa keratitis have been known to be regulated by various cytokines and other regulatory factors. This study was undertaken to investigate the change in the expression of IRF–1, IRF–7 and inducible nitrogen oxide synthetase (iNOS) in the mice cornea with Pseudomonas aeruginosa keratitis. Methods: BALB/c mice were topically inoculated with 5–µl bacterial suspension containing 1.0 x 106 CFU of Pseudomonas aeruginosa after scarifying the cornea with 1 mm sized three horizontal scratches. Normal corneas and scarified corneas without microbial inoculation served as controls. IRF–1, IRF–7, and iNOS expressions were analyzed by Western blot assay at 24 hours after the infection. NOS enzymatic activity was measured by monitoring the ability of tissue homogenate to convert [U–14C]arginine to [U–14C]citrulline. Results: Protein expression of IRF–1 and IRF–7 increased in corneas infected with Pseudomonas aeruginosa compared to normal or wounded cornea. iNOS protein was also highly expressed in the infected cornea. NOS enzymatic activity increased in infected cornea, but control corneas and scarified corneas had negligible amounts of NOS activity. Conclusions: IRF–1 and IRF–7 play an important role in regulating iNOS induced immune response against Pseudomonas aeruginosa keratitis in mice. A detailed understanding of the molecular mechanisms involved in Pseudomonas aeruginosa keratitis may lead to the discovery of potential therapeutic agents.
Keywords: cornea: basic science • bacterial disease • Pseudomonas