title: Fish skeletal muscle tissue is an important focus of immune reactions during pathogen infection.
abstract: Skeletal muscle in mammals can express and secrete immune-related molecules during pathogen infection. Despite in fish is known that classical immune tissues participate in innate immunity, the role of skeletal muscle in this function is poorly understood. To determine the immunocompetence of fish skeletal muscle, juvenile fine flounder (Paralichthys adpersus) were challenged with Vibrio ordalii. Different Toll-like receptors, pro-inflammatory cytokines (TNFα, Il-1β, and IL-8), and immune-effector molecules (NKEF and the antimicrobial peptides hepcidin and LEAP-2) were analyzed. Infection initially triggered IL-1β upregulation and P38-MAPK/AP-1 pathway activation. Next, the NFĸB pathway was activated, together with an upregulation of intracellular Toll-like receptor expressions (tlr3, tlr8a tlr9, and tlr21), TNFα production, and leap-2 expression. Finally, transcriptions of il-1β, il-8, tnfα, nkef-a, and hepcidin were also upregulated. These results suggest that fish skeletal muscle is an immunologically active organ that could play an important role against pathogens.
authors.affiliation: Universidad Andres Bello, Laboratorio de Biotecnología Molecular, Departamento de Ciencias Biológicas, Facultad Ciencias Biológicas, 8370146 Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile. Electronic address: valenzuela.i.cristian@gmail.com.
authors.forename: Cristián A
authors.initials: CA
authors.lastname: Valenzuela
authors.affiliation: Universidad Andres Bello, Laboratorio de Biotecnología Molecular, Departamento de Ciencias Biológicas, Facultad Ciencias Biológicas, 8370146 Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile. Electronic address: r.zuloaga@uandresbello.edu.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Zuloaga
authors.affiliation: Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile; Universidad Andres Bello, Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, 2520000 Viña del Mar, Chile. Electronic address: matias.poblete.m@gmail.com.
authors.forename: Matías
authors.initials: M
authors.lastname: Poblete-Morales
authors.affiliation: Universidad Andres Bello, Laboratorio de Biotecnología Molecular, Departamento de Ciencias Biológicas, Facultad Ciencias Biológicas, 8370146 Santiago, Chile. Electronic address: ta.vera@uandresbello.edu.
authors.forename: Tamara
authors.initials: T
authors.lastname: Vera-Tobar
authors.affiliation: Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, 2340000 Valparaíso, Chile. Electronic address: luis.mercado@pucv.cl.
authors.forename: Luis
authors.initials: L
authors.lastname: Mercado
authors.affiliation: Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile; Universidad Andres Bello, Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, 2520000 Viña del Mar, Chile; Universidad Andres Bello, Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ecología y Recursos Naturales, 2340000 Valparaíso, Chile. Electronic address: ravendano@unab.cl.
authors.forename: Ruben
authors.initials: R
authors.lastname: Avendaño-Herrera
authors.affiliation: Universidad Andres Bello, Laboratorio de Biotecnología Molecular, Departamento de Ciencias Biológicas, Facultad Ciencias Biológicas, 8370146 Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile; Universidad Andres Bello, Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ecología y Recursos Naturales, 2340000 Valparaíso, Chile. Electronic address: jvaldes@unab.cl.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Valdés
authors.affiliation: Universidad Andres Bello, Laboratorio de Biotecnología Molecular, Departamento de Ciencias Biológicas, Facultad Ciencias Biológicas, 8370146 Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), 4030000 Concepción, Chile; Universidad Andres Bello, Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ecología y Recursos Naturales, 2340000 Valparaíso, Chile. Electronic address: amolina@unab.cl.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Molina
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000276:immunology*; D005432:Flounder / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D018482:Muscle, Skeletal / Q000276:immunology*; D014733:Vibrio; D014735:Vibrio Infections / Q000276:immunology
keywords: Antimicrobial peptides; Fish; Immune-related genes; TLRs; V. ordalii