ABSTRACT
Objective To assess the expression of the corneal epithelial TJ protein claudin -1 in type 2 diabetic rats at different time points.Methods 80 eight-week-old male SD rats were randomly divided into the normal control and diabetic mellitus(DM) groups(n =40 each).A high-fat diet combined with STZ injection was used to induce type 2 DM.Normal and diabetic rats were sacrificed at 4, 8, 16 weeks respectively(after STZ injection) before de-bridement.Hematoxylin and eosin was used to study the morphological differences between normal and diabetic cor -nea.Immunofluorescene and Western blot were used to determine the expression of corneal epithelial TJ protein claudin-1.Results Corneal epithelial cells reduction and stroma edema were evident at 8 and 16 weeks by HE. Claudin-1 expression in the corneal epithelium of the diabetic group was lower and fainter compared to the normal group at 16 weeks(after STZ injection)(P <0.05), which were similar to the normal group at 4 and 8 weeks.Con-clusion Continual hyperglycemia has a negative effect on ocular surface tissues and the expression of corneal epi -thelial tight junction protein claudin -1 with progressing of type 2 diabetic mellitus.