title: Dynamic transcriptional regulation of autocrine/paracrine igfbp1, 2, 3, 4, 5, and 6 in the skeletal muscle of the fine flounder during different nutritional statuses.
abstract: The IGF-binding proteins (IGFBPs) play a dual role in the regulation of the activity and bioavailability of IGFs in different tissues. Diverse evidence has shown that IGFBPs can inhibit and/or potentiate IGF actions. In this study, igfbp1, 2, 3, 4, 5, and 6 were isolated in the fine flounder, a flat fish species that shows slow growth and inherent Gh resistance in muscle. Subsequently, the expression of all igfbps was assessed in the skeletal muscle of flounder that underwent different nutritional statuses. igfbp1 was not expressed in muscle during any of the nutritional conditions, whereas igfbp3 and igfbp5 were the lowest and the highest igfbps expressed respectively. A dynamic expression pattern was found in all the igfbps expressed in skeletal muscle, which depended on the nutritional status and sampling period. During the fasting period, igfbp2, 4, and 5 were downregulated, whereas igfbp3 was upregulated during part of the fasting period. The restoration of food modulated the expression of the igfbps dynamically, showing significant changes during both the long- and short-term refeeding. igfbp3 and igfbp6 were downregulated during short-term refeeding, whereas igfbp5 was upregulated, and igfbp2 and igfbp4 remained stable. During long-term refeeding, the expression of igfbp2, 4, 5, and 6 increased, while igfbp3 remained unchanged. In conclusion, this study shows for the first time the isolation of all igfbps in a single fish species, in addition to describing a dynamic nutritional and time-dependent response in the expression of igfbps in the skeletal muscle of a nonmammalian species.
authors.affiliation: Laboratorio de Biotecnologia Molecular, Departmento de Ciencias Biologicas, Facultad de Biologia, Universidad Andres Bello, Avenida Republica 217, 8370146 Santiago, Chile.
authors.forename: Diego
authors.initials: D
authors.lastname: Safian
authors.forename: Eduardo N
authors.initials: EN
authors.lastname: Fuentes
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Valdés
authors.forename: Alfredo
authors.initials: A
authors.lastname: Molina
mesh_terms: D000595:Amino Acid Sequence; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D019898:Autocrine Communication / Q000235:genetics; D016000:Cluster Analysis; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000502:physiology; D029941:Fish Proteins / Q000145:classification / Q000235:genetics*; D005432:Flounder / Q000235:genetics*; D020869:Gene Expression Profiling; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000235:genetics; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000235:genetics; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics; D018976:Insulin-Like Growth Factor Binding Protein 6 / Q000235:genetics; D018969:Insulin-Like Growth Factor Binding Proteins / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism*; D019899:Paracrine Communication / Q000235:genetics; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D029941:Fish Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D018975:Insulin-Like Growth Factor Binding Protein 5; D018976:Insulin-Like Growth Factor Binding Protein 6; D018969:Insulin-Like Growth Factor Binding Proteins