Preadipocyte differentiation capacity declines between middle and old age. Expression of
the adipogenic transcription factors, CCAAT/enhancer-binding protein (C/EBP) α and
peroxisome proliferator-activated receptor γ (PPARγ), is lower in differentiating
preadipocytes from old than young animals, although no age-related changes occur in
C/EBPβ mRNA, which is upstream of C/EBPα and PPARγ. C/EBPβ-liver-enriched inhibitory
protein (C/EBPβ-LIP), a truncated C/EBPβ isoform that is a dominant inhibitor of …