Acanthopanax senticosus Promotes Survival of Tilapia Infected With Streptococcus iniae by Regulating the PI3K/AKT and Fatty Acid Metabolism Signaling Pathway

Frontiers in Physiology

Chang You Song¹  Pao Xu¹  Jun Qiang¹  Hong Xia Li¹ 

[1] Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China;Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China;

关键词: Acanthopanax senticosus;    genetic improvement of farmed tilapia;    Streptococcus iniae;    metabolism;    immune response;   

DOI  :  10.3389/fphys.2021.699247

来源: DOAJ

【 摘 要 】

Streptococcus has greatly restricted the development of healthy tilapia aquaculture. As a green and efficient feed addition, Acanthopanax senticosus (APS) has been increasingly used in culture, but it is unclear whether it represents a disease-resistant feed. Genetically improved farmed tilapia (GIFT, Oreochromis niloticus) was fed with a feed supplemented with 0 (control), 0.5, 1, 2, 4, and 8‰ APS for 56 days, after which fish were injected with 5.9 × 106 CFU/ml Streptococcus iniae into the abdominal cavity. At 96 h after infection, the cumulative survival of GIFT in control and 0.5‰ APS treatments was significantly lower than in other treatments; at APS supplementation rates of 1 and 2‰, serum glucose, triglycerides, and cholesterol contents were all significantly lower than in control treatment fish. Hepatic glycogen and triglyceride contents of 1‰ APS treatment fish were significantly higher than those in fish in control treatment. Transcription levels of peroxisome proliferator activated receptor α (PPAR), fatty acid synthase (FAS), and lipoprotein Lipase (LPL) genes were upregulated, and their expression levels in fish in 1, 2, and 4‰ treatments were significantly higher than those in fish in control treatment at 96 h after S. iniae infection. After 96 h of infection, the red blood cells, hemoglobin, hematocrit, and white blood cells of fish in 1‰ APS treatment were significantly lower than those of fish in 4 and 8‰ treatments; hepatic catalase activity was activated at 48 h, superoxide dismutase activity was also significantly upregulated at 96 h, and the malondialdehyde content significantly decreased. It is noted that 0.5–2‰ APS treatments significantly activated the expression of PI3K and AKT in the liver, while inhibiting the expression of Caspase-9. Therefore, feed with 1‰ APS can promote hepatic glycogen and lipid metabolism in GIFT after infection with S. iniae, which is beneficial to alleviating oxidative stress damage and cell apoptosis in liver tissue.

【 授权许可】

Unknown