Yang Yujia, Fu Qiang, Zhou Tao, Li Yun, Liu Shikai, Zeng Qifan, Wang Xiaozhu, Jin Yulin, Tian Changxu, Qin Zhenkui, Dunham Rex, Liu Zhanjiang
The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
Dev Comp Immunol. 2017 Feb;67:464-470. doi: 10.1016/j.dci.2016.09.007. Epub 2016 Sep 15.
Apolipoproteins are protein component of plasma lipoproteins. They exert crucial roles in lipoprotein metabolism and serve as enzyme cofactors, receptor ligands, and lipid transfer carriers in mammals. In teleosts, apolipoproteins are also involved in diverse processes including embryonic and ontogenic development, liver and digestive system organogenesis, and innate immunity. In this study, we identified a set of 19 apolipoprotein genes in channel catfish (Ictalurus punctatus). Phylogenetic analysis and syntenic analysis were conducted to determine their identities and evolutionary relationships. The expression signatures of apolipoproteins in channel catfish were determined in healthy tissues and after infections with two major bacterial pathogens, Edwardsiella ictaluri and Flavobacterium columnare. In healthy channel catfish, most apolipoprotein genes exhibited tissue-specific expression patterns in channel catfish. After ESC and columnaris infections, 5 and 7 apolipoprotein genes were differentially expressed respectively, which presented a pathogen-specific and time-dependent pattern of regulation. After ESC infection, three exchangeable apolipoproteins (apoA-IB, apoC-I, and apoE-B) were suppressed in catfish intestine, while two nonexchangeable apolipoproteins (apoB-A and apoB-B) were slightly up-regulated. After columnaris infection, apoB-B, apoD-B, and apoE-A were significantly down-regulated in catfish gill, while apoF, apoL-IV, apoO-like, and apo-14 kDa showed significantly up-regulation. Taken together, these results suggested that apolipoprotein genes may play significant roles in innate immune responses to bacterial pathogens in channel catfish.
载脂蛋白是血浆脂蛋白的蛋白质成分。它们在脂蛋白代谢中发挥关键作用，并在哺乳动物中作为酶辅因子、受体配体和脂质转运载体。在硬骨鱼中，载脂蛋白还参与多种过程，包括胚胎发育和个体发育、肝脏和消化系统器官发生以及先天免疫。在本研究中，我们在斑点叉尾鮰（Ictalurus punctatus）中鉴定出一组19个载脂蛋白基因。进行了系统发育分析和共线性分析以确定它们的身份和进化关系。在健康组织以及感染两种主要细菌病原体鮰爱德华氏菌（Edwardsiella ictaluri）和柱状黄杆菌（Flavobacterium columnare）后，测定了斑点叉尾鮰中载脂蛋白的表达特征。在健康的斑点叉尾鮰中，大多数载脂蛋白基因在斑点叉尾鮰中呈现组织特异性表达模式。在感染鮰爱德华氏菌和柱状黄杆菌后，分别有5个和7个载脂蛋白基因差异表达，呈现出病原体特异性和时间依赖性的调控模式。感染鮰爱德华氏菌后，斑点叉尾鮰肠道中的三种可交换载脂蛋白（apoA-IB、apoC-I和apoE-B）受到抑制，而两种不可交换载脂蛋白（apoB-A和apoB-B）略有上调。感染柱状黄杆菌后，斑点叉尾鮰鳃中的apoB-B、apoD-B和apoE-A显著下调，而apoF、apoL-IV、apoO样蛋白和14 kDa载脂蛋白则显著上调。综上所述，这些结果表明载脂蛋白基因可能在斑点叉尾鮰对细菌病原体的先天免疫反应中发挥重要作用。
