title: An in vitro method for studying the proliferation and differentiation of Atlantic salmon preadipocytes.
abstract: The aim of the present study was to develop a cell culture system for studying the proliferation and differentiation of preadipocytes isolated from Atlantic salmon adipose tissue. The expression of proliferating cell nuclear antigen (PCNA) was used as a marker for cell proliferation. The cells started to proliferate within 48 h after seeding and continued to proliferate throughout the culture period of 2 wk. Undifferentiated preadipocytes showed a fibroblast-like morphology with a homogeneous cytoplasm devoid of lipid droplets. At confluence, an exogenous lipid mixture was added to the cell cultures. The preadipocytes became larger and rounder during the subsequent days, and the cytoplasm gradually filled with lipid-rich droplets. These droplets were revealed by oil red O staining. Immunocytochemical staining showed that differentiated adipocytes expressed detectable levels of the three regulatory proteins associated with adipocyte differentiation: peroxisome proliferator-activated receptor gamma (PPARgamma), CCAAT/enhancer binding protein alpha (C/EBPalpha), and leptin. The cells also showed activity of glycerol-3-phosphate dehydrogenase (GPDH) (EC 1.1.1.8), a biochemical marker of adipocyte differentiation. The morphological and biochemical data presented here show that fish preadipocytes have properties that are similar to those of preadipocytes in mammals. We conclude therefore that salmon adipose tissue contains a sizable population of preadipocytes. Exogenous lipids promote the activation of adipose-related genes and induce the differentiation of fish preadipocytes in vitro.
authors.affiliation: AKVAFORSK, Institute of Aquaculture Research, NO-1432 As, Norway. anne.vegusdal@akvaforsk.nlh.no
authors.forename: Anne
authors.initials: A
authors.lastname: Vegusdal
authors.forename: Hilde
authors.initials: H
authors.lastname: Sundvold
authors.forename: Tor
authors.initials: T
authors.lastname: Gjøen
authors.forename: Bente
authors.initials: B
authors.lastname: Ruyter
mesh_terms: D017667:Adipocytes / Q000166:cytology*; D000818:Animals; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D020317:Salmo salar; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D020738:Leptin; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D005993:Glycerolphosphate Dehydrogenase