豆粕对松浦镜鲤肠黏膜能量代谢、肠道健康相关基因表达的影响及α-酮戊二酸缓解作用

Effects of soybean meal on intestinal mucosal energy metabolism,intestinal health gene expression and alleviating effect of a-ketoglutaric on Cyprinus carpio Songpu

为探究豆粕对松浦镜鲤肠道健康及能量水平的影响及AKG缓解肠道损伤的作用机制。选取初始体重为(9.51±0.06)g松浦镜鲤幼鱼609尾,随机分为7组,每组3个重复,每缸29尾鱼。对照组(FM)饲喂30.8%鱼粉为蛋白源饲料,实验组以40%豆粕为基础饲料(SM),AKG组、Met组和Com组分别在SM基础上添加1%AKG、300 mg/kg Metformin和0.2 mg/kg Compound-c,Met+AKG组和Com+AKG组为在AKG组上分别添加Metformin和Compound-c。实验共59 d。结果显示,与FM组比,SM组后肠黏膜ATP和ADP含量显著升高;前肠ACC、TNF-α、IL-1β、TGFβ2、caspase9、Claudin7、Claudin11、Claudin3c、Occludin,中肠AMPK-α、TOR、ACC、IL-1β、TGFβ1、Caspase8、Claudin7、Occludin及后肠TGFβ1、Caspase8、Caspase9基因表达显著降低;后肠TNF-α、Claudin11、Claudin3c和Occludin显著升高。与SM组比,AKG组前肠TGFβ1、Claudin7、Claudin11,前肠及中肠TOR显著升高;中肠caspase8、TNF-α、Claudin11,后肠Claudin11、Occludin显著降低。Met组和Com组上调后肠ADP和AMP含量。Met组上调前肠AMPK-α、TNF-α、IL-1β、Caspase9、Claudin7、Claudin11、Claudin3c,中肠TGFβ1、Claudin11,后肠IL-1β、Claudin7,中肠及后肠TOR表达量;下调后肠Occludin表达量;Com组上调前肠Occludin表达量,下调中肠及后肠Claudin11和后肠Occludin表达量。与AKG组相比,Com+AKG组后肠ATP、ADP及AMP含量和Met+AKG组后肠ADP含量均显著升高。Met+AKG、Com+AKG降低前肠Claudin7、Claudin11和中肠TOR的表达量。Met+AKG上调前肠caspase8、中肠Claudin11和后肠Claudin7表达量。Com+AKG显著提高后肠Claudin11和Occludin表达量。研究表明,豆粕降低前肠及中肠能量水平,抑制AMPK-α和TOR表达,降低前肠及中肠紧密连接蛋白的基因表达;引起后肠肠道炎症。AKG通过提高前肠TOR、紧密连接、抗炎因子的表达,减少中肠及后肠促炎因子的产生,减缓中肠及后肠的细胞凋亡,缓解豆粕对鲤肠道的损伤。

This experiment was performed to investigate the effects of soybean meal on intestinal health of Songpu Mirror carp(Cyprinus carpio Songpu)as well as the mechanism of AKG alleviating intestinal injury.A total of 609 juvenile Songpu mirror carp with an initial body weight of(9.510.06)g were randomly divided into 7 groups with 3 replicates per group and 29 fish per group.The control group was fed with 30.8%fish meal(FM group)as the protein source.The experimental group was fed with 40%soybean meal(SM group)as basic diet.The AKG group were fed with the basic diet supplemented with 1%a-ketoglutarate.Groups Met and Com were fed with the basic diet supplemented with 300 mg/kg Metformin and 0.2 mg/kg Compound C respectively.Groups Met+AKG and Com+AKG were supplemented with Metformin and Compound C on the basis of AKG group respectively.The experiment lasted for 59 days.Compared with FM group,mucosa ATP and ADP contents of the distal intestine(DI)were significantly increased(P<0.05)in SM group.Meanwhile,the expression of ACC,tumor necrosis factor alfa(TNF-α),interleukin-1 beta(IL-1βB),transforming growth factor-beta(TGFβ2),caspase9,Claudin7,Claudin11,Claudin3c,Occludin in the proximal intestine(PI),the expression of AMP-activated protein kinase alfa(AMPK-a),target of rapamycin(TOR),ACC,IL-1β,TGFβ1,Caspase8,Claudin7,Occludin in the mid intestine(MI),the expression of TGFβ1,caspase8,caspase9 in the DI were significantly decreased and the expression of TNF-a,Claudinl1,Claudin3c,Occludin in the DI were significantly increased(P<0.05)in SM.Compared with SM,the expression of TGFβ1(PI),Claudin7(PI),Claudin11(PI,MI and DI),TOR(PI and MI),caspase8(MI),TNF-α(MI)and Occludin(DI)were significantly decreased(P<0.05)in AKG group.The ADP and AMP contents of mucosa of DI were significantly increased in Met and Com group.Subsequently,the expression of AMPK-α(PI),TOR(MI and DI),TNF-α(PI),IL-1β(PI),Caspase9(PI),Claudin7(PI),Claudin11(PI and MI),Claudin3c(PI),TGFβ1(MI)were significantly increased and the expression of Occludin were significantly decreased in Met group.The expression of Occludin(PI)were significantly increased and the expression of Claudinl1(MI and DI)and Occludin(DI)were significantly decreased in Com group.Compared with AKG,the ATP,ADP and AMP contents of mucosa of DI were significantly increased in Com+AKG group.The ADP contents of mucosa of DI were significantly increased in Met+AKG group.The expression of Claudin7(PI),Claudin11(PI)and TOR(MI)were significantly decreased in Met+AKG and Com+AKG.Morever,the expression of caspase8(PI),Claudinl1(MI)and Claudin7(DI)were significantly increased in Met+AKG.The expression of Claudin11(DI)and Occludin(DI)were significantly increased in Com+AKG(P<0.05).In conclusion,soybean meal decreased the energy level of PI and MI,but inhibited the expression of AMPK-α,TOR and ACC,and further decreased the expression of tight junction protein in PI and MI.Intestinal inflammation in DI was triggered.AKG can improve the expression of TOR,tight junction and anti-inflammatory factors in PI,reduce the expression of pro-inflammatory factors in MI and DI,alleviate the apoptosis of MI and DI by inhibiting endogenous apoptosis,and alleviate the damage of soybean meal to the intestine of carp.This study found the way that soy protein would damage intestinal health,and its effect on intestinal mucosal energy metabolism and the mechanism of AKG in alleviating intestinal injury.So this may provide a theoretical basis for improving the application of soybean in aquatic animal production.