EARLY TIMP GENE-EXPRESSION AFTER CORNEAL INFECTION WITH PSEUDOMONAS-AERUGINOSA

PURPOSE. To evaluate the expression of tissue inhibitor of metalloprot einases (TIMP) mRNA in corneal tissues before and at early time points (6 and 12 hours and 1, 3, and 5 days) after corneal infection with Ps eudomonas aeruginosa. METHODS. Ribonuclease protection assays were use d to detect and quantitate TIMP mRNA expression in uninfected (wounded and unwounded) and in wounded corneas inoculated with P. aeruginosa. RESULTS. Expression of TIMP-1 mRNA was undetectable in either wounded or unwounded, uninfected corneal tissues, but it increased in a time-d ependent manner with peak expression occurring at 3 days after corneal wounding and bacterial inoculation. Constitutive low-level mRNA expre ssion of TIMP-2 was detected in both groups of uninfected corneal tiss ues; these groups remained essentially unchanged after corneal abrasio n and bacterial inoculation. TIMP-3 mRNA was detected in uninfected (w ounded and unwounded) corneal tissues and appeared to decrease in a ti me-dependent manner after corneal abrasion and bacterial inoculation. CONCLUSIONS. The evidence indicated that TIMPs were expressed in infec ted and in uninfected (wounded and unwounded) corneal tissues. In addi tion, these data suggested that TIMP expression appeared to be indepen dently regulated.