Effect of Experimental Dry Eye on Expression of Matrix Metalloproteinases and TIMPs by the Ocular Surface Epithelia

Abstract

 

Abstract:

 

To determine the effect of experimental dry eye onproduction of matrix metalloproteinases (MMPs) and their physiologicalinhibitors (TIMPs) by the corneal and conjunctival epithelium.

 

Balb–C and C57BL6 mice aged 6–8weeks were treated with subcutaneous injections of 2.5 mg/mlscopolamine hydrobromide, 4 times per day and exposure to anair draft and low humidity for 5 and 10 days. Untreated micewere used as controls.To study gene expression, real time PCRwas performed using Taqman Probes and the results were analyzedby the comparative C_T method, selecting the relative mRNA levelsin the untreated control as calibrator. Immunofluorescent stainingwas performed using specific antibodies to identify the localizationof MMPs proteins.

 

A change in the expression of the MMPs and TIMPs inresponse to experimental dryness was observed. The greatestdifferences between strains were observed for MMP3,7,9, TIMP1and 3 in the corneal epithelium and for MMP7,9, and TIMP1,2and 3 in the conjunctival epithelium (Tables). The greatestdifferences between cornea and conjunctiva epithelium was seenfor MMP13,3 and TIMP4 in Balb–c mice and for MMP13,9,and all TIMPs in C57 mice. The immunofluorescent staining wasconsistent with changes in gene expression in most cases.

 

Experimental dry eye induces a change in expressionof MMPs and TIMPs that is different in these two strains ofmice. Further investigation is required to determine the mechanismsregulating these changes.

 

 

 

 

Keywords: cornea: tears/tear film/dry eye • conjunctiva • gene/expression