表没食子儿茶素没食子酸酯对福美双诱导的肉鸡胫骨软骨发育不良的影响

Effect of EGCG on tibial dyschondroplasia induced by thiram in broiler chick

旨在研究表没食子儿茶素没食子酸酯(EGCG)通过调控热休克蛋白HSP90的表达对肉鸡胫骨软骨发育不良(TD)的影响。试验将120羽1日龄健康AA肉鸡预饲1周后随机分成3组:对照组、TD发生组和EGCG处理组。通过向基础日粮中添加药物的方式,分别对TD发生组和EGCG处理组雏鸡饲喂25mg/kg的福美双,诱发TD。从第3日起,对EGCG处理组雏鸡每天腹腔注射10mg/kg的EGCG。14d后,全部扑杀试验鸡。形态学检查肉鸡胫骨生长板发育状况;HE染色法观察生长板软骨细胞分化和血管生成变化;Real-time PCR和Western blot法分别检测HSP90基因和蛋白表达差异。结果显示,TD发生组雏鸡TD症状明显,HSP90基因和蛋白表达量均明显上升。EGCG处理组雏鸡TD症状明显缓解,HSP90基因和蛋白表达量显著下降;生长板软骨细胞分化和血管浸润显著恢复。由此推测,EGCG可能通过下调HSP90基因和蛋白在TD肉鸡软骨细胞中的表达,恢复TD胫骨病变区软骨细胞分化和血管生成,抑制TD发生,提高肉鸡健康状况。

This study was undertaken to investigate the effect of（-）-epigallocatechin-3-gallate（EGCG）on tibial dyschondroplasia（TD）through modulating the HSP90 expression.A total of120a-day-old broiler chicks were divided initially into three groups：the control group,the thiram group and the EGCG treatment group.All the chicks from the thiram group and EGCG treatment group were received a standard normal diet with the addition of 50mg/kg of thiram.After 2days,the chicks from the EGCG treatment group were simultaneously given 10mg/kg EGCG in an intraperitoneal way.All the chicks were sacrificed on day 14.Results in the present study showd that EGCG relieved the TD symptom mainly through restoring chondrocyte differentiation and angiogenesis in the hypertrophic zone.There was a significant up-regulation of HSP90 gene expression and protein synthesis in the TD suffered chicks.The application of EGCG to TD chicks significantly reduced the HSP90 expression,close to the level of the control group.In conclusion,EGCG exhibited a significant inhibition on TD in broiler chick.This function was speculated to achieve through decreasing the HSP90 expression,which ultimately contribute to the normalization of the chondrocyte differentiation and angiogenesis in the grow plate of TD chicks.