Expression of CCAAT/enhancer binding proteins during porcine preadipocyte differentiation.
The expression of three CCAAT/enhancer-binding proteins (C/EBPs) was examined with immunocytochemistry and Western blot analysis during preadipocyte differentiation in porcine stromal vascular (S-V) cell cultures. Regardless of treatment and time in culture, immunoreactivity for all three C/EBP isoforms was restricted to cell nuclei. At day 1, 50 +/- 6% of S-V cells were C/EBPdelta positive, whereas 13 +/- 3 and 11.7 +/- 3% of S-V cells were AD-3 and C/EBPalpha positive, respectively. After 3 days of seeding in fetal bovine serum (FBS) and dexamethasone (DEX), C/EBPdelta; AD-3, and C/EBPalpha-positive cells increased to 67 +/- 5, 42 +/- 4, and 32 +/- 3%, respectively. Double staining clearly showed that most of the C/EBPalpha reactive cells had not accumulated appreciable lipid after 3 days of FBS + DEX. Following 3 days of insulin treatment, the percentage of C/EBPdelta cells was 50 +/- 6, whereas the percentage of AD-3- and C/EBPalpha-positive cells was 41 +/- 4 and 31 +/- 3, respectively. After insulin treatment all fat cells were AD-3, C/EBPalpha, and C/EBPdelta positive. Double staining demonstrated that fat cells were C/EBPdelta reactive throughout the culture period. Western blotting showed changes in C/EBP isoform expression that were consistent with the immunocytochemical results. We conclude that C/EBPalpha is a terminal differentiation marker which is expressed later than AD-3 but further studies are needed to determine the relationship between C/EBPdelta and adipogenesis in porcine S-V cultures.
Yu
Z K
ZK
Department of Foods and Nutrition, the University of Georgia, Athens, Georgia, 30602, USA.
Hausman
G J
GJ
D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology; D015415:Biomarkers; D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins; D002452:Cell Count / Q000187:drug effects; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology; D050356:Lipid Metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism*; D017154:Stromal Cells; D013552:Swine; D013997:Time Factors
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015415:Biomarkers; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D007328:Insulin; D009687:Nuclear Proteins; D020033:Protein Isoforms; D003907:Dexamethasone