Fig. 2a–c.

Effects of age and CR on preadipocyte differentiation-related transcription factors in WAT. a Western blot analysis to detect sterol regulatory element-binding protein-1 (SREBP-1),and peroxisome proliferators-activated receptors (PPAR) γ and γ2 protein levels in WAT nuclear extracts (50 μg protein) from each group. Transcription factors SREBP-1, PPAR-γ, and -γ2 are involved in preadipocyte differentiation; these transcription factors decreased in aged AL rats but increased with age in CR rats. b,c Nuclear extracts for each group were prepared and assayed for SREBP-1 and PPAR induction by electrophoretic mobility shift assay (EMSA) as described in Materials and methods. *P < 0.05, ** P< 0.01, and *** P< 0.001 compared with 5-month-old AL rats; # P < 0.05, ## P < 0.01, ### P< 0.001 compared with each CR rat, respectively