短期饲喂黄曲霉毒素B_1对凡纳滨对虾肝胰腺抗氧化酶活性及基因表达的影响

Effects of short term feeding high concentrations of aflatoxin B_1(AFB_1) on the hepatopancreas antioxidant enzyme activity and gene expression of Litopenaeus vannamei

为了研究短期饲喂黄曲霉毒素B1对凡纳滨对虾(Litopenaeus vannamei)肝胰腺抗氧化酶活性、mTOR信号通路及免疫相关基因表达的影响,试验选取体质健康、规格均匀的凡纳滨对虾[初始体质量(2.40±0.13)g]300尾,将其随机分为2组,分别投喂含有0mg/kg(对照组)和15mg/kg(试验组)黄曲霉毒素B(1AFB1)的饲料12d。在试验的第1、4、8d和12d分别取对照组和试验组对虾的肝胰腺进行抗氧化酶活性、免疫和营养相关基因表达的测定。结果表明,投喂含有AFB1的饲料,对凡纳滨对虾肝胰腺中的超氧化物歧化酶(SOD)、过氧化物酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽-S转移酶(GST)活性均显著高于对照组(P<0.05)。真核细胞始动因子4E结合蛋白(4EBP)和GST基因表达水平在试验期间均显著高于对照组(P<0.05);核糖体S6蛋白激酶(P70s6k)基因表达水平在第4d时达到最大值,为对照组的3.33倍,而在8d和12d时显著低于对照组(P<0.05);真核细胞翻译启动因子1(eIF4E1A)和真核细胞翻译启动因子2(eIF4E2)基因表达水平在第1d时达到最大值,分别为对照组的1.64和1.87倍,而在第12d时均显著低于对照组(P<0.05);酚氧化酶原(ProPO)和Rab蛋白(Rab)基因的表达水平在第1、4d和8d时均显著高于对照组(P<0.05),在第4d和8d时达到最大值,分别为对照组的6.37和60.51倍,而在第12d时表达水平均下降。研究认为,短期投喂高浓度AFB1对凡纳滨对虾肝胰腺抗氧化酶活性、mTOR信号通路及免疫相关基因表达产生了显著的影响,对其机体免疫防御系统有明显的破坏作用。

To investigate the effects of aflatoxin B^（AFB,） on the antioxidant enzyme activities, immune and nutrition related genes expression in Litopenaeus vannamei, 300 shrimps were randomly divided into two groups and fed two diets containing 0 and 15 mg/kg AFB,（diet）. Superoxide dismutase（SOD）, peroxidase（CAT）, glutathione peroxidase （GSH-Px） and glutathione S-transferase （GST） levels, and expression of the 4EBP, GST, elF4E1A, eIF4E2, PT0s6k, Rab and ProPO genes in the hepatopancreas of L. vannamei, were analyzed. The results demonstrated that SOD, CAT, GSH-Px, GST activities and 4EBP, GST genes expression in the hepatopancreas in shrimp that were fed diets supplemented with AFB1 were significantly higher than those of control group（P〈0.05）. Relative expression levels of eIF4E1A, eIF4E2, P70s6k, Rab and ProPO were up-regulated when compared to the control group in the early stage of experiment, then gradually decreased. In conclusion, the antioxidant enzyme activities and immune related gene expression of hepatopancreas were significantly influenced by high level of AFB~ for a short term, and significant destructive effect to the shrimp＇s immune system. This study aims at providing scientific and effective basis for the prevention and elimination of the influence of AFBt, through the research of the damage pro-cess and mechanism of hepatopancreas.