Pan Mingzhu, Liu Danni, Liu Jiahuan, Li Xinxin, Huang Dong, Luo Kai, Liu Yue, Wu Zhenhua, Zhang Wenbing, Mai Kangsen
The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), Fisheries College, Ocean University of China, Qingdao, 266003, China.
The Key Laboratory of Mariculture (Ministry of Education), The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), Fisheries College, Ocean University of China, Qingdao, 266003, China; Liaoning Ocean and Fisheries Science Research Institute, Dalian, Liaoning, 116023, China.
Fish Shellfish Immunol. 2022 Nov;130:560-571. doi: 10.1016/j.fsi.2022.07.063. Epub 2022 Aug 6.
Excessive dietary carbohydrate commonly impairs the functions of liver and intestine in carnivorous fish. In the present study, a 10-week feeding trial was carried out to explore the regulation of biotin on the hepatic and intestinal inflammation and apoptosis in turbot (Scophthalmus maximus L.) fed with high carbohydrate diets. Three isonitrogenous and isolipidic experimental diets were designed as follows: the CC diet with 18.6% of carbohydrate and 0.04 mg/kg of biotin, the HC diet with 26.9% of carbohydrate and 0.05 mg/kg of biotin, and the HCB diet with 26.9% of carbohydrate and 1.62 mg/kg of biotin. Results showed that high dietary carbohydrate (HC diet) impaired the morphology of liver and intestine, however, inclusion of dietary biotin (HCB diet) normalized their morphology. Inflammation-related gene expression of nuclear factor κB p65 (nf-κb p65), tumor necrosis factor α (tnf-α), interleukin-1β (il-1β), il-6 and il-8, and the protein expression of NF-κB p65 in the liver and intestine were significantly up-regulated in the HC group compared to those in the CC group (P < 0.05), the HCB diet decreased their expression compared to the HC group (P < 0.05). The gene expression of il-10 and transforming growth factor-β (tgf-β) in the liver and intestine were significantly decreased in the HC group compared to the CC group (P < 0.05), and inclusion of dietary biotin increased the il-10 and tgf-β expression in the liver and intestine (P < 0.05). Moreover, compared to the CC group, the HC group had a stronger degree of DNA fragmentation and more TUNEL-positive cells in the liver and intestine, and the HCB group had a slighter degree of DNA fragmentation and fewer TUNEL-positive cells compared to the HC group. Meanwhile, the gene expression of B-cell lymphoma protein-2-associated X protein (bax) and executor apoptosis-related cysteine peptidase 3 (caspase-3) were significantly up-regulated and the gene expression of B-cell lymphoma-2 (bcl-2) was significantly down-regulated both in the liver and intestine in the HC group compared with those in the CC group (P < 0.05). Inclusion of dietary biotin significantly decreased the bax and caspase-3 mRNA levels and increased bcl-2 mRNA level in the liver and intestine (P < 0.05). In conclusion, high dietary carbohydrate (26.9% vs 18.6%) induced inflammation and apoptosis in liver and intestine. Supplementation of biotin (1.62 mg/kg vs 0.05 mg/kg) in diet can alleviate the high-dietary-carbohydrate-induced hepatic and intestinal inflammation as well as inhibit apoptosis in turbot. The present study provides basic data for the application of biotin into feed, especially the high-carbohydrate feed for turbot.
过量的膳食碳水化合物通常会损害肉食性鱼类肝脏和肠道的功能。在本研究中，进行了为期10周的饲养试验，以探究生物素对饲喂高碳水化合物饲料的大菱鲆（Scophthalmus maximus L.）肝脏和肠道炎症及细胞凋亡的调节作用。设计了三种等氮等脂的实验饲料如下：碳水化合物含量为18.6%且生物素含量为0.04 mg/kg的CC饲料、碳水化合物含量为26.9%且生物素含量为0.05 mg/kg的HC饲料、碳水化合物含量为26.9%且生物素含量为1.62 mg/kg的HCB饲料。结果表明，高膳食碳水化合物（HC饲料）损害了肝脏和肠道的形态，然而，添加膳食生物素（HCB饲料）使其形态恢复正常。与CC组相比，HC组肝脏和肠道中炎症相关基因核因子κB p65（nf-κb p65）、肿瘤坏死因子α（tnf-α）、白细胞介素-1β（il-1β）、il-6和il-8的表达以及NF-κB p65的蛋白表达均显著上调（P < 0.05），与HC组相比，HCB饲料降低了它们的表达（P < 0.05）。与CC组相比，HC组肝脏和肠道中il-10和转化生长因子-β（tgf-β）的基因表达显著降低（P < 0.05），添加膳食生物素增加了肝脏和肠道中il-10和tgf-β的表达（P < 0.05）。此外，与CC组相比，HC组肝脏和肠道中的DNA片段化程度更强且TUNEL阳性细胞更多，与HC组相比，HCB组的DNA片段化程度更轻且TUNEL阳性细胞更少。同时，与CC组相比，HC组肝脏和肠道中B细胞淋巴瘤蛋白-2相关X蛋白（bax）和执行凋亡相关半胱氨酸肽酶3（caspase-3）的基因表达均显著上调，而B细胞淋巴瘤-2（bcl-2）的基因表达显著下调（P < 0.05）。添加膳食生物素显著降低了肝脏和肠道中bax和caspase-3的mRNA水平，并增加了bcl-2的mRNA水平（P < 0.05）。总之，高膳食碳水化合物（26.9%对18.6%）诱导了肝脏和肠道的炎症及细胞凋亡。在饲料中补充生物素（1.62 mg/kg对0.05 mg/kg）可以减轻高膳食碳水化合物诱导的肝脏和肠道炎症，并抑制大菱鲆的细胞凋亡。本研究为生物素在饲料中的应用提供了基础数据，特别是在大菱鲆高碳水化合物饲料中的应用。
