脱氧雪腐镰刀菌烯醇与T⁃2毒素对热应激蛋鸡肠道屏障功能及内质网应激和炎症反应的影响

Endoplasmic Reticulum Stress and Inflammatory Response of Laying Hens under Heat Stress

本试验旨在研究脱氧雪腐镰刀菌烯醇(DON)与T-2毒素对热应激蛋鸡肠道屏障功能及内质网应激和炎症反应的影响。选择36周龄体重相近的京红1号蛋鸡96只,随机分成4组,每组8个重复,每个重复3只鸡。对照组(CON组)饲喂基础饲粮,DON组、T-2组、DON+T-2组分别在基础饲粮中添加3.00 mg/kg DON、0.50 mg/kg T-2毒素、1.50 mg/kg DON+0.25 mg/kg T-2毒素。预试期3 d,正试期28 d。试验期间白天平均温湿指数为84.87。结果表明:1)与CON组相比,T-2组十二指肠、空肠隐窝深度显著升高(P<0.05),DON+T-2组空肠隐窝深度显著升高(P<0.05),DON、T-2、DON+T-2组十二指肠绒毛高度/隐窝深度(V/C)值显著降低(P<0.05),T-2、DON+T-2组空肠V/C值显著降低(P<0.05),DON组回肠隐窝深度显著升高(P<0.05)。2)与CON组相比,DON、T-2、DON+T-2组血清脂多糖(LPS)含量显著升高(P<0.05),DON+T-2组血清二胺氧化酶(DAO)含量显著升高(P<0.05)。3)与CON组相比,DON、T-2组回肠黏膜白细胞介素-6(IL-6)含量显著升高(P<0.05)。4)与CON组相比,T-2、DON+T-2组回肠黏膜闭锁蛋白(Occludin)mRNA相对表达量显著降低(P<0.05)。5)与CON组相比,DON+T-2组回肠黏膜葡萄糖调节蛋白78(GRP78)、X盒结合蛋白1(XBP1)mRNA相对表达量显著升高(P<0.05),DON组回肠黏膜活化转录因子4(ATF4)mRNA相对表达量显著升高(P<0.05)。由此可见,在夏季热应激条件下,饲粮中添加3.00 mg/kg DON和0.50 mg/kg T-2毒素可诱导蛋鸡小肠组织内质网应激和炎症反应,损伤黏膜形态结构和屏障功能,且两者存在一定的累加效应。

This experiment was conducted to investigate the effects of deoxynivalenol(DON)and T-2 toxin on intestinal barrier function,endoplasmic reticulum stress and inflammatory response of laying hens under heat stress.Ninety-six 36-week-old Jinghong No.1 laying hens with similar body weight were randomly divided into 4 groups with 8 replicates per group and 3 hens per replicate.Broilers in the control group(CON group)were fed a basal diet,and others in DON group,T-2 group and DON+T-2 group were fed basal diets supplemented with 3.00 mg/kg DON,0.50 mg/kg T-2 toxin and 1.50 mg/kg DON+0.25 mg/kg T-2 toxin,respectively.The pretrial period lasted for 3 days,and the trial period lasted for 28 days.The average daytime temperature and humidity index was 84.87.The results showed as follows:1)compared with CON group,the duodenal and jejunal crypt depth in T-2 group was significantly increased(P<0.05),the jejunal crypt depth in DON+T-2 group was significantly increased(P<0.05),the duodenal villus height/crypt depth(V/C)value in DON,T-2 and DON+T-2 groups was significantly decreased(P<0.05),the jejunal V/C value in T-2 and DON+T-2 groups was significantly decreased(P<0.05),and the ileal crypt depth in DON group was significantly increased(P<0.05).2)Compared with CON group,the serum lipopolysaccharide(LPS)content in DON,T-2 and DON+T-2 groups was significantly increased(P<0.05),and the serum diamine oxidase(DAO)content in DON+T-2 group was significantly increased(P<0.05).3)Compared with CON group,the ileum mucosal interleukin-6(IL-6)content in DON,T-2 and DON+T-2 groups was significantly increased(P<0.05).4)Compared with CON group,the ileum mucosal Occludin mRNA relative expression levels in T-2 and DON+T-2 groups was significantly decreased(P<0.05).5)Compared with CON group,the mRNA relative expression levels of glucose regulatory protein 78(GRP78)and X-box binding protein 1(XBP1)in ileum mucosa in DON+T-2 group were significantly increased(P<0.05),and the ileum mucosal activated transcription factor 4(ATF4)mRNA relative expression level in DON group was significantly increased(P<0.05).In conclusion,under the condition of summer heat stress,dietary supplementation of 3.00 mg/kg DON and 0.50 mg/kg T-2 can induce endoplasmic reticulum stress and inflammation in small intestine tissues of laying hens,and damage mucosal morphology and barrier function,and the two have detailed cumulative effects.