糖尿病大鼠病程不同阶段角膜上皮紧密连接蛋白 claudin－1表达的变化

摘要

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.%目的：动态观察不同阶段糖尿病（DM）大鼠和正常（NC）大鼠角膜上皮紧密连接蛋白 claudin－1的表达变化。方法雄性 SD 大鼠80只，随机均等分为 DM 组和 NC 组，以高脂饮食联合小剂量链脲佐菌素（STZ）腹腔注射建立Ⅱ型 DM 模型，分别于造模后4周、8周、16周处死大鼠，取角膜组织；以 HE 染色法比较 DM 组和 NC 组大鼠角膜形态学变化，以免疫荧光染色和 Western blot 法检测大鼠角膜上皮紧密连接蛋白 claudin－1的表达。结果造模后8周和16周，DM 组大鼠角膜上皮细胞排列疏松，基质层水肿明显。造模后16周 DM 组和 NC 组大鼠角膜上皮 claudin－1蛋白表达差异有统计学意义（P ＜0．05），在造模后4周和8周表达差异无统计学意义。结论随 DM 病程延长，Ⅱ型 DM 可能导致大鼠角膜上皮紧密连接蛋白 claudin－1表达降低。