Effect of AICAR on the expression of key adipogenic transcription factors during 3T3L1 adipocyte differentiation. The differentiating 3T3-L1 cells were treated with different concentrations of AICAR (from 0.1 to 1.0 mM) and proteins were isolated at various time periods (from 0 to 9 days). Immunoblot analysis for various key adipogenic transcription factors including C/EBPα, C/EBPβ, PPARγ and SREBP1 were examined as described in Materials and Methods (a). The expression levels of PPARγ, SREBP1, C/EBPα, Pref-1, aP2 and adipsin mRNA were estimated by quantitative PCR (qPCR) using their specific primers as described in Materials and Methods (b). The relative qPCR values were normalized with respect to 18S rRNA expression levels. Values are mean ± S.D. of three determinations. *P < 0.05, *** p < 0.001 as compared with untreated cells. NS not significant; *p < 0.05, $ p < 0.001 as compared to 3 days differentiated samples. % p < 0.001 as compared to 6 days differentiated samples. @ p < 0.001 as compared to 9 days differentiated samples.