Figure 6.

Effects of garcinol and p300 siRNA on leptin-stimulated A549 cells. Serum-starved A549 cells were pretreated with the OB-R antibody (2 µg/mL), U0126 (10 µM), SB202190 (10 µM), SP600125 (10 µM), Bay11-7082 (10 µM), or garcinol (1 µM) for 1 h. Other cells were transfected with 100 nM p300 siRNA or scrambled siRNA as described in the Experimental section. The cells were then incubated with 1 µg/mL of leptin for the indicated time intervals. At the end of the incubation, the cells were harvested and cell lysates were extracted. (A,B) Expression of cPLA₂-α and p300; (C) phosphorylation of p65; and (D) acetylation of histone H4 were detected using Western blot with specific antibodies. Cell membranes were stripped and reprobed with the anti-GAPDH antibody as internal controls. The data are expressed as mean ± SEM of 5 independent experiments (n = 5). & p < 0.05 as compared with the cells exposed to the vehicle alone; # p < 0.01 as compared with the cells exposed to the leptin or scrambled siRNA transfected groups.