Defective adipocyte differentiation in mice lacking the C/EBPbeta and/or C/EBPdelta gene.
To investigate the role of C/EBP family members during adipocyte differentiation in vivo, we have generated mice lacking the C/EBPbeta and/or C/EBPdelta by gene targeting. Approximately 85% of C/EBPbeta(-/-).delta(-/-) mice died at the early neonatal stage. By 20 h after birth, brown adipose tissue of the interscapular region in wild-type mice contained many lipid droplets, whereas C/EBPbeta(-/-).delta(-/-) mice did not accumulate droplets. In addition, the epidydimal fat pad weight of surviving adult C/EBPbeta(-/-).delta(-/-) mice was significantly reduced compared with wild-type mice. However, these adipose tissues in C/EBPbeta(-/-).delta(-/-) mice exhibit normal expression of C/EBPalpha and PPARgamma, despite impaired adipogenesis. These results demonstrated that C/EBPbeta and C/EBPdelta have a synergistic role in terminal adipocyte differentiation in vivo. The induction of C/EBPalpha and PPARgamma does not always require C/EBPbeta and C/EBPdelta, but co-expression of C/EBPalpha and PPARgamma is not sufficient for complete adipocyte differentiation in the absence of C/EBPbeta and C/EBPdelta.
Tanaka
T
T
Department of Biochemistry, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663, Japan.
Yoshida
N
N
Kishimoto
T
T
Akira
S
S
D017667:Adipocytes / Q000166:cytology*; D000273:Adipose Tissue / Q000166:cytology / Q000196:embryology / Q000254:growth & development*; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D022762:CCAAT-Enhancer-Binding Proteins; D002454:Cell Differentiation / Q000235:genetics*; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004622:Embryo, Mammalian; D004822:Epididymis; D005838:Genotype; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D009929:Organ Size; D014157:Transcription Factors / Q000172:deficiency*
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors