大菱鲆IGF结合蛋白的营养调控功能

NUTRITIONAL REGULATION OF IGF-BINDING PROTEIN IN TURBOT(SCOPHTHALMUS MAXIMUS L.)

为揭示IGF结合蛋白(Insulin-like growth factor binding protein, IGFBP)对水产动物生理生长和营养代谢的影响,选取大菱鲆肌成纤维细胞作为研究对象,通过生物信息学分析将斑马鱼(Danio rerio)、智人(Homo sapiens)和大菱鲆(Scophthalmus maximus L.)中igfbp基因的氨基酸序列共同进行分析推断进化历史,对肌成纤维细胞进行IGFBPs的抑制剂(NBI 31772)和IGF1R的抑制剂(BMS 554417)处理,通过荧光定量PCR、蛋白免疫印迹、Annexin V-FITC染色、代谢物测定等分析。结果显示:大菱鲆IGFBP家族共有12个基因,不同的igfbp基因具有显著的组织表达特异性。在脑、鳃、胆囊组织中igfbp2a表达量最高;在眼、肌肉、肾脏、皮肤组织中igfbp5a表达量最高;在脾脏和心脏组织中igfbp3b表达量最高;在肝脏组织中igfbp2b表达量最高;在肠组织中igfbp4表达量最高;大菱鲆肌成纤维细胞在营养诱导后igfbp1a、igfbp3b、igfbp4、igfbp5a和igfbp5b基因表达呈先下降后上升的趋势。igf2相较于igf1对营养应答更敏感。短期抑制IGFBPs能够促进IGF的信号激活能力,而长期抑制IGFBPs则降低IGF的活性并导致细胞凋亡。此外,长期抑制IGFBPs会造成糖酵解和三羧酸循环代谢中间物含量降低,但会积累细胞内游离必需氨基酸。研究成果为进一步认识IGFBPs及IGF信号通路在水产动物中的作用提供了新的参考。

To investigate the impact of IGF-like growth factor binding protein(IGFBP)on the physiological growth and nutritional metabolism of aquatic animals,turbot muscle fibroblasts were chosen as the research subject.The amino acid sequence of igfbp gene in zebrafish(Danio rerio),Homo sapiens(Homo sapiens)and turbot(Scophthalmus maximus L.)was collectively analyzed through bioinformatics to infer their evolutionary history.Furthermore,turbot muscle fibroblasts were treated with IGFBPs inhibitor(NBI 31772)and IGF1R inhibitor(BMS 554417),followed by analysis using fluorescence quantitative PCR,protein western blotting,Annexin V-FITC staining,and metabolite deter-mination.In this study,we investigated the IGFBP family in turbot,identifying 12 genes with distinct tissue expression patterns.Our findings reveal significant tissue-specific expression of different igfbp genes.Specifically,igfbp2a exhi-bited the highest expression in brain,gill,and gallbladder tissues,while igfbp5a displayed peak expression in the eye,muscle,kidney,and skin.Moreover,igfbp3b showed the highest expression in spleen and heart tissue,igfbp2b in the liver,and igfbp4 in intestinal tissues.Additionally,our study sheds light on the dynamic response of IGFBP expression to nutritional induction in turbot muscle fibroblasts.The expression levels of igfbp1a,igfbp3b,igfbp4,igfbp5a,and igfbp5b in turbot muscle fibroblasts decreased first and then increased after nutritional induction.Moreover,our results indicate that igf2 displays greater sensitivity to nutritional stimuli compared to igf1.We also investigated the effects of short-term and long-term inhibition of IGFBPs on IGF signaling.Short-term inhibition promoted IGF signaling,while long-term inhibition resulted in reduced IGF activity and apoptosis.In addition,prolonged IGFBP inhibition led to decreased glycolysis and tricarboxylic acid cycle metabolite levels,alongside intracellular accumulation of free amino acids.In summary,these results provide valuable insights into the role of IGFBPs and the IGF signaling pathways in aquatic animals,offering a foundation for further exploration in this field.