Figure 3

Leptin gene expression in adipocytes single culture without nicotine (white bar) or with nicotine (pale gray bar), and in adipocytes co-cultured with macrophages in the absence of nicotine (dark gray bar) and in the presence of nicotine (black bar). (A) One μM of nicotine was used for experiments. Co-culture with macrophages greatly suppressed leptin gene expression in adipocytes. Addition of nicotine further suppressed leptin gene expression after 12 h of stimulation. The data are expressed as fold changes of baseline data (expression at 0 h). *p < 0.05, **p < 0.001. (B) Hundred μM of nicotine was used for the experiments. In this condition, nicotine further suppressed leptin gene expression at 8 h after nicotine stimulation which was markedly suppressed when the adipocytes were co-cultured with macrophages. However, nicotine did not directly suppress leptin gene expression in adipocytes. The data are expressed as fold changes of baseline data (expression at 0 h). *p < 0.05, **p < 0.001.