title: Immunohistochemical evidence for myofibroblast-like cells associated with liver injury induced by aflatoxin B1 in rainbow trout (Oncorhynchus mykiss).
abstract: In mammalian species, profibrogenic cells are activated to become myofibroblasts in response to liver damage. Few studies have examined hepatic myofibroblasts and their role in liver damage in teleosts. The aim of the present study was to investigate the involvement of myofibroblast-like cells in rainbow trout (Oncorhynchus mykiss) with hepatic damage induced by aflatoxin B1 (AFB1). Histopathological and immunohistochemical analyses characterized alterations in the liver stroma during the carcinogenic process. Anti-human α-smooth muscle actin (SMA) and anti-human desmin primary antibodies were used in immunohistochemistry. Only the anti-SMA reagent labelled cells in trout liver. In the livers of control fish, only smooth muscle in blood vessels and around bile ducts was labelled. In the livers from AFB1-treated fish, SMA-positive cells were present in the stroma surrounding neoplastic lesions and in areas of desmoplastic reaction. These observations indicate that in teleosts, as in mammals, the myofibroblast-like cell is involved in fibrosis associated with liver injury. Chronic liver injury induced in trout by aflatoxin may provide a useful model system for study of the evolution of such mechanisms.
authors.affiliation: Department of Histology and Embryology, Institute of Biology, University of Campinas (UNICAMP), CP: 6109, CEP: 13083-970 Campinas, São Paulo, Brazil. Electronic address: aranas@unicamp.br.
authors.forename: S
authors.initials: S
authors.lastname: Arana
authors.affiliation: Department of Pathology, School of Medicine, São Paulo University, São Paulo.
authors.forename: V A F
authors.initials: VA
authors.lastname: Alves
authors.affiliation: Adolfo Lutz Institute, São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Sabino
authors.affiliation: Estação Experimental de Salmonicultura Dr. Ascânio de Faria, APTA, Secretaria de Agricultura e Abastecimento de São Paulo, São Paulo, Brazil.
authors.forename: Y A
authors.initials: YA
authors.lastname: Tabata
authors.affiliation: Adolfo Lutz Institute, São Paulo, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Nonogaki
authors.affiliation: Department of Pathology, School of Veterinary Medicine and Animal Sciences, São Paulo University, São Paulo, Brazil.
authors.forename: M-L
authors.initials: ML
authors.lastname: Zaidan-Dagli
authors.affiliation: Department of Surgery, School of Veterinary Medicine and Animal Science, São Paulo University, São Paulo, Brazil.
authors.forename: F J
authors.initials: FJ
authors.lastname: Hernandez-Blazquez
mesh_terms: D016604:Aflatoxin B1; D000818:Animals; D056486:Chemical and Drug Induced Liver Injury / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology*; D017686:Oncorhynchus mykiss
chemical_list: D016604:Aflatoxin B1
keywords: fish; hepatocarcinogenesis; liver fibrosis; myofibroblast