A 100-day feeding trial was conducted to investigate the influences of dietary lipid levels on the immunity and mechanism in abalone Haliotis discus hannai Ino. Abalones (initial weight: 10.98 ± 0.05 g) were fed with graded levels of dietary lipid, which were 15.73, 23.41, 31.72, 38.25, 46.35, 55.63, 61.70 and 67.19 g/kg. Results showed that compared with the treatment with 38.25 g/kg of dietary lipid, 67.19 g/kg of dietary lipid increased the cumulative mortality of abalone after a challenge with Vibrio parahaemolyticus. Meanwhile, 67.19 g/kg of dietary lipid decreased the activities of lysozyme (LZ) and acid phosphatase (ACP) in serum, and the mRNA levels of β-defensin and mytimacin 6 in hepatopancreas of abalone. The mRNA levels of tumour necrosis factor α (tnfα), activator protein 1 (ap-1), nuclear factor κB (nf-κb), interleukin 1 receptor-associated kinase-4 (irak4), myeloid differentiation primary response protein MyD88 (myd88), toll-like receptor 2 (tlr2), tlr4 and perilipin-2, and the protein level of interleukin-1β (IL-1β), TNFα, NF-κBp65, AP-1, MyD88 and Perilipin-2 in hepatopancreas were up-regulated by 67.19 g/kg of dietary lipid. However, the mRNA levels of arginase and inhibitor of κBα (iκbα) were down-regulated. Besides, 67.19 g/kg of dietary lipid up-regulated the mRNA levels of executor apoptosis-related cysteine peptidase 3 (caspase-3), caspase-7 and B-cell lymphoma protein-2-associated X protein (bax), and the protein levels of caspase-3 and c-Jun N-terminal kinases (JNK) in hepatopancreas. Moreover, high dietary lipid level down-regulated the mRNA levels of copper/zinc superoxide dismutase (cuznsod), manganese superoxide dismutase (mnsod), catalase (cat), glutathione peroxidase (gpx), glutathione-S-transferase (gst) and NF-E2-related factor 2 (nrf2), while up-regulated the mRNA and protein levels of Kelch-like ECH-associated protein 1 (Keap1) in hepatopancreas. It was concluded that a high level (67.19 g/kg) of dietary lipid decreased the immunity of abalone, which might be related to the aggravated inflammation and apoptosis, and decreased anti-oxidative capacity under Perilipin-2/TLRs/MyD88/IRAK4/(NF-κB or AP-1), JNK/Bcl-2/Bax and Keap1/Nrf2 signalling.

中文翻译：

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高膳食脂水平降低鲍鱼的免疫力和抗病能力并影响perilipin-2/TLR4、JNK和Keap1/Nrf2通路

开展为期100天的饲养试验，研究日粮血脂水平对鲍鱼Haliotis discus hannai Ino免疫力的影响及其机制。鲍鱼（初始重量：10.98 ± 0.05 g）的日粮脂质水平为 15.73、23.41、31.72、38.25、46.35、55.63、61.70 和 67.19 g/kg。结果表明，与 38.25 g/kg 膳食脂质处理相比，67.19 g/kg 膳食脂质增加了鲍鱼在副溶血性弧菌攻击后的累积死亡率。同时，67.19 g/kg的膳食脂质降低了血清中溶菌酶（LZ）和酸性磷酸酶（ACP）的活性，以及β-防御素和mytimacin 6的mRNA水平。在鲍鱼的肝胰腺中。肿瘤坏死因子α（tnfα）、激活蛋白1（ap - 1）、核因子κB（nf - κb）、白细胞介素1受体相关激酶4（irak4）、骨髓分化初级反应蛋白MyD88（myd88 ）的mRNA水平)、toll 样受体 2 ( tlr2 )、tlr4和perilipin - 2，肝胰腺中 IL-1β (IL-1β)、TNFα、NF-κBp65、AP-1、MyD88 和 Perilipin-2 蛋白水平升高-受 67.19 g/kg 膳食脂质的调节。然而，精氨酸酶和 κBα 抑制剂的 mRNA 水平（iκbα ) 被下调。此外，67.19 g/kg 膳食脂质上调执行者凋亡相关半胱氨酸肽酶 3 ( caspase - 3 )、caspase - 7和 B 细胞淋巴瘤蛋白-2 相关 X 蛋白 ( bax ) 的 mRNA 水平，以及肝胰腺中 caspase-3 和 c-Jun N-末端激酶 (JNK) 的蛋白水平。此外，高膳食脂质水平下调铜/锌超氧化物歧化酶（ cuznsod ） 、锰超氧化物歧化酶（mnsod）、过氧化氢酶（cat）、谷胱甘肽过氧化物酶（gpx）、谷胱甘肽-S-转移酶（gst）和 NF的 mRNA 水平-E2 相关因子 2 (nrf2 )，同时上调肝胰腺中 Kelch 样 ECH 相关蛋白 1 (Keap1) 的 mRNA 和蛋白质水平。得出结论，高水平（67.19 g/kg）的膳食脂质降低了鲍鱼的免疫力，这可能与Perilipin-2/TLRs/MyD88/IRAK4/下的炎症和细胞凋亡加重以及抗氧化能力降低有关。 （NF-κB 或 AP-1）、JNK/Bcl-2/Bax 和 Keap1/Nrf2 信号传导。