本研究旨在评估从山板山卡米素(SePCH)的饮食硒蛋白提取物对生长的影响,血液学参数,硒代谢,免疫反应,抗氧化能力,幼年大口鲈鱼(Micropterussalmoides)的炎症反应和肠屏障功能。基础日粮中添加了四种不同浓度的SePCH:0.00、0.30、0.60和1.20g/Kg(实际硒含量:0.37、0.59、0.84和1.30mg/kg)。在60天的培养期内,这些浓度用于为幼年大嘴鲈鱼配制四种等氮和等能量饮食。与对照组(0.00g/Kg)相比,充足的饮食SePCH(0.60和1.20g/Kg)显着增加了体重增加和每日生长速率。此外,0.60和1.20g/KgSePCH显着增加了白细胞的数量,红细胞,血小板,淋巴细胞和单核细胞,和血红蛋白的水平,血细胞中的平均红细胞体积和平均红细胞血红蛋白。此外,0.60和1.20g/Kg的SePCH增加硒代半胱氨酸裂解酶的mRNA表达水平,硒磷酸合酶1,15kDa硒蛋白,硒蛋白T2,硒蛋白H,与对照组相比,鱼肝和肠道中的硒蛋白P和硒蛋白K。充足的SePCH不仅显著提高了抗氧化酶的活性(总超氧化物歧化酶,过氧化氢酶,谷胱甘肽还原酶,谷胱甘肽过氧化物酶),总抗氧化能力和谷胱甘肽的水平,而NF-E2相关因子2,Cu/Zn-超氧化物歧化酶的mRNA转录水平增加,过氧化氢酶,谷胱甘肽还原酶和谷胱甘肽过氧化物酶。然而,与对照组相比,充足的SePCH显着降低了鱼肝和肠道中丙二醛和H2O2的水平以及海带样ECH相关蛋白1a和海带样ECH相关蛋白1b的mRNA表达水平。同时,足够的SePCH显着增强了免疫因子的水平(碱性磷酸酶,酸性磷酸酶,溶菌酶,补体成分3,补体成分4和免疫球蛋白M)和先天免疫相关基因(溶菌酶,铁调素,与对照组相比,鱼肝和肠道中肝脏表达的抗菌肽2,补体成分3和补体成分4)。足够的SePCH降低了促炎细胞因子的水平(肿瘤坏死因子-α,白细胞介素8、白细胞介素1β和干扰素γ),同时增加肝脏和肠道中转录和蛋白质水平的转化生长因子β1水平。丝裂原活化蛋白激酶13(MAPK13)mRNA表达水平,与对照组相比,饲喂0.60和1.20g/KgSePCH的鱼的肝脏和肠道中的MAPK14和核因子κBp65显着降低。组织学切片还表明,与对照相比,0.60和1.20g/KgSePCH显著增加肠绒毛高度和绒毛宽度。此外,与对照组相比,0.60和1.20g/KgSePCH组的肠上皮细胞中紧密连接蛋白(闭塞带-1、闭塞带-3、Claudin-1、Claudin-3、Claudin-5、Claudin-11、Claudin-23和Claudin-34)和Mucin-17的mRNA表达水平显著上调。总之,这些结果发现,0.60和1.20g/Kg日粮SePCH不仅可以改善生长,血液学参数,硒代谢,抗氧化能力,增强免疫反应和肠道功能,但也减轻炎症反应。此信息可作为配制大嘴鲈鱼饲料的有用参考。
This study aimed to assess the impact of dietary selenoprotein extracts from Cardamine hupingshanensis (SePCH) on the growth, hematological parameters, selenium metabolism, immune responses, antioxidant capacities, inflammatory reactions and intestinal barrier functions in juvenile largemouth bass (Micropterus salmoides). The base diet was supplemented with four different concentrations of SePCH: 0.00, 0.30, 0.60 and 1.20 g/Kg (actual selenium contents: 0.37, 0.59, 0.84 and 1.30 mg/kg). These concentrations were used to formulate four isonitrogenous and isoenergetic diets for juvenile largemouth bass during a 60-day culture period. Adequate dietary SePCH (0.60 and 1.20 g/Kg) significantly increased weight gain and daily growth rate compared to the control groups (0.00 g/Kg). Furthermore, 0.60 and 1.20 g/Kg SePCH significantly enhanced amounts of white blood cells, red blood cells, platelets, lymphocytes and monocytes, and levels of hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin in the hemocytes. In addition, 0.60 and 1.20 g/Kg SePCH increased the mRNA expression levels of selenocysteine lyase, selenophosphate synthase 1, 15 kDa selenoprotein, selenoprotein T2, selenoprotein H, selenoprotein P and selenoprotein K in the fish liver and intestine compared to the controls. Adequate SePCH not only significantly elevated the activities of antioxidant enzymes (Total superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase), the levels of total antioxidant capacity and glutathione, while increased mRNA transcription levels of NF-E2-related factor 2, Cu/Zn-superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase. However, adequate SePCH significantly decreased levels of malondialdehyde and H2O2 and the mRNA expression levels of kelch-like ECH-associated protein 1a and kelch-like ECH-associated protein 1b in the fish liver and intestine compared to the controls. Meanwhile, adequate SePCH markedly enhanced the levels of immune factors (alkaline phosphatase, acid phosphatase, lysozyme, complement component 3, complement component 4 and immunoglobulin M) and innate immune-related genes (lysozyme, hepcidin, liver-expressed antimicrobial peptide 2, complement component 3 and complement component 4) in the fish liver and intestine compared to the controls. Adequate SePCH reduced the levels of pro-inflammatory cytokines (tumour necrosis factor-α, interleukin 8, interleukin 1β and interferon γ), while increasing transforming growth factor β1 levels at both transcriptional and protein levels in the liver and intestine. The mRNA expression levels of mitogen-activated protein kinase 13 (MAPK 13), MAPK14 and nuclear factor kappa B p65 were significantly reduced in the liver and intestine of fish fed with 0.60 and 1.20 g/Kg SePCH compared to the controls. Histological sections also demonstrated that 0.60 and 1.20 g/Kg SePCH significantly increased intestinal villus height and villus width compared to the controls. Furthermore, the mRNA expression levels of tight junction proteins (zonula occludens-1, zonula occludens-3, Claudin-1, Claudin-3, Claudin-5, Claudin-11, Claudin-23 and Claudin-34) and Mucin-17 were significantly upregulated in the intestinal epithelial cells of 0.60 and 1.20 g/Kg SePCH groups compared to the controls. In conclusion, these results found that 0.60 and 1.20 g/Kg dietary SePCH can not only improve growth, hematological parameters, selenium metabolism, antioxidant capacities, enhance immune responses and intestinal functions, but also alleviate inflammatory responses. This information can serve as a useful reference for formulating feeds for largemouth bass.