投喂雨生红球藻虾青素条件下的虹鳟血清代谢组学研究

Serum Metabolomics of Rainbow Trout(Oncorhynchus mykiss)Fed with Haematococcus pluvialis Astaxanthin

为研究饲料中添加雨生红球藻(Haematococcus pluvialis)虾青素条件下虹鳟(Oncorhynchus mykiss)血清的代谢响应,以虹鳟商业饲料作为基础饲料(HPA0),添加雨生红球藻,配制2种虾青素含量分别为15 mg/kg和30 mg/kg的实验饲料(分别记为HPA15和HPA30)。实验分HPA0、HPA15和HPA303组,每组3个重复,分别投喂初始体重为0.60 kg左右的虹鳟,养殖周期为16周。养殖结束后,对不同实验组虹鳟血清中的代谢物进行检测,并筛选差异代谢物,然后通过KEGG数据库进行关键代谢通路的富集分析。结果显示,HPA0与HPA15组之间筛选出棕榈酸、棕榈烯酸、磷脂酰胆碱、2-甲基-3-氧代丙酸和乙基葡萄糖醛酸苷等5种代谢物,且其含量均在HPA15组中显著上调,这些差异代谢物主要涉及脂肪酸生物合成代谢、亚油酸代谢、α-亚麻酸代谢等代谢通路;HPA0与HPA30组之间筛选出11种差异代谢物,其中,棕榈酸、棕榈烯酸、磷脂酰胆碱、水苏糖、虾青素、磷脂酰肌醇、γ-谷氨酰亮氨酸和氧化芳樟醇的水平在HPA30组中显著上调,而乙内酰脲-5-丙酸、磷脂酰乙醇胺和邻苯二甲酸单乙基己酯的水平在HPA30组中显著下调,这些差异代谢物主要涉及甘油磷脂代谢、脂肪酸生物合成代谢、亚油酸代谢、自噬等代谢通路;HPA15组与HPA30组之间筛选出9种差异代谢物,其中,鸟嘌呤核苷、肌酸、磷脂酰肌醇、虾青素和8-羟基脱氧鸟苷的水平在HPA30组中显著上调,而磷脂酰胆碱、乙基葡萄糖醛酸苷、2-甲基-3-氧代丙酸和尿苷酸的水平在HPA30组中显著下调,这些差异代谢物主要涉及亚油酸代谢,α-亚麻酸代谢,甘氨酸、丝氨酸和苏氨酸代谢,以及甘油磷脂代谢等代谢通路。研究表明,饲料中添加雨生红球藻虾青素可显著提高虹鳟血清中的虾青素水平,有利于降低体内的氧化程度,提高血清中的磷脂酰胆碱和磷脂酰肌醇水平,促进亚油酸、α-亚麻酸、花生四烯酸和甘油磷脂的生物合成代谢,有助于细胞功能的稳定。

In order to investigate the metabolic response of rainbow trout(Oncorhynchus mykiss)fed with Haematococcus pluvialis astaxanthin,the commercial feed of Oncorhynchus mykiss was used as basic feed(HPA0),and Haematococcus pluvialis were added to prepare two experimental diets,and the astaxanthin content was 15 mg/kg and 30 mg/kg,respectively(defined as HPA15 and HPA30).There were three experiment groups(HPA0,HPA15,and HPA30),and each group has three replicates.The Oncorhynchus mykiss with an initial body weight of about 0.60 kg were cultured for 16 weeks.The serum metabolites were detected,and the differential metabolites were screened,and then the enrichment analysis of key metabolic pathways was conducted with KEGG database.The results showed that five differential metabolites(palmitic acid,palmitoleic acid,phosphatidylcholine,2-methyl-3-oxopropanoic acid,and ethyl glucuronide)were screened between the HPA0 group and HPA15 group,and their levels were significantly up-regulated in HPA15.These differential metabolites were mainly involved in fatty acid biosynthesis metabolism,linoleic acid metabolism,α-linolenic acid metabolism.Eleven differential metabolites in the serum were screened between the HPA0 group and HPA30 group;among which the levels of palmitic acid,palmitoleic acid,phosphatidylcholine,stachyose,astaxanthin,phosphatidylinositol,gamma-glutamylleucine,and linalool oxide were significantly up-regulated in HPA30 group,while the levels of hydantoin-5-propionic acid,phosphatidyl ethanolamine,and monoethylhexyl phthalic acid were significantly down-regulated in HPA30 group.These differential metabolites were mainly involved in glycerol phospholipid metabolism,fatty acid biosynthesis metabolism,linoleic acid metabolism,and autophagy.Nine different metabolites were screened between HPA15 group and HPA30 group,among which the levels of guanine riboside,creatine,phosphatidyl inositol,astaxanthin and 8-hydroxydeoxyguanosine were significantly up-regulated in HPA30 group,while the levels of phosphatidylcholine,ethyl glucuronide,2-methyl-3-oxy-propionic acid and uridine were significantly down-regulated in HPA30 group.These differential metabolites were mainly involved in linoleic acid metabolism,α-linolenic acid metabolism,glycine,serine and threonine metabolism,glycerol phospholipid metabolism and other metabolic pathways.This study suggested that dietary supplementation of Haematococcus pluvialis astaxanthin significantly increased the astaxanthin content in the serum,which was conducive to reducing the degree of oxidation in the body of Oncorhynchus mykiss,increasing the levels of phosphatidylcholine and phosphatidylinositol in serum,and promoting the biosynthesis metabolism of linoleic acidα-linolenic acid,arachidonic acid and glycerol phospholipid,which contribute to the stability of cell function.