热暴露后大鼠食管紧密连接蛋白表达的改变

The expression of tight junction protein in rat esophagus after heat exposure

目的研究热应激对食管黏膜上皮屏障功能的影响。方法建立大鼠热暴露动物模型,HE染色观察大鼠食管黏膜上皮组织学改变,IHC和Western blot检测食管黏膜上皮细胞紧密连接蛋白Occludin,ZO-1的表达,检测蛋白酶切激活受体-2(PAR-2)的表达。结果热暴露后大鼠食管黏膜上皮结构没有明显的组织学改变,IHC显示Occludin主要表达于复层扁平上皮细胞膜,热暴露后表达Occludin的阳性细胞层数减少;ZO-1主要表达于复层扁平上皮细胞的胞质和细胞核,热暴露后其表达不变或轻度升高;PAR-2主要表达于复层扁平上皮细胞的细胞浆,热暴露后其表达减弱。Western blot显示,食管组织Occludin的表达下降,ZO-1表达升高,PAR-2表达下降。结论热暴露引起的热应激改变了食管上皮紧密连接蛋白Occludin,ZO-1的表达,提示食管黏膜上皮细胞屏障功能可能发生改变,而PAR-2的表达也发生改变,提示可能参与了屏障功能的改变。

Objective To investigate the effect of heat stress on the mucosa barrier function of oesophagus in rat.Methods A rat model of heat exposure was established,and the histological change of esophageal mucosa was observed and the expression of tight junction protein Occludin,ZO-1 and the expression of PAR-2,IHC and western blot respectively were examined.Results There was no obvious histological change in the epithelial structure of esophageal mucosa after heat exposure in rats.IHC showed that Occludin was mainly expressed in laminated membrane of flattened epithelial cells,but the expression was decreased after heat exposure.ZO-1 was mainly expressed in the cytoplasm and nucleus offlattened epithelial cells,its expression was not changed or slightly increased after heat exposure.PAR-2 wasmainly expressed in the cytoplasm of flattened epithelial cells,which was decreased after heat exposure.According to the western blot,the expression of Occludin and PAR-2 in esophageal tissue was decreased,while the expression of ZO-1 was increased.Conclusion Decrease of Occludin and ZO-1 indicates that the esophageal mucosa barrier function might be impaired by the heat stress induced by heat exposure,and the increased expression of PAR-2 suggests that it may also be involved in barrier function.