Redox Regulation of the AMP-Activated Protein Kinase
Figure 4
Reactive oxygen species (ROS) involved in Berberine induced AMPK activation are derived from mitochondria.
A, Effects of xanthine oxidase inhibitors, allopurinol and oxypurinol, on Berberine-enhanced phosphorylation of AMPK-Thr172 and ACC-Ser79 in BAEC. BAEC were pre-treated with mitochondrial tempol (50 µM) for 30 min, and then treated with Berberine (10 µM) for 2 h. The blots are representative of three independent experiments. B, Effects of adenoviral overexpression of p47phox dominant negative mutants on Berberine-enhanced phosphorylation of AMPK-Thr172 and ACC-Ser79 in BAEC. The blots are representative of three independent experiments. C & D, Effects of mitochondrial tempol (*p<0.05, control versus Berberine-treated, #p<0.05, Berberine-alone versus Berberine plus mitochondrial tempol). E & F, Effects of UCP-2 siRNA transfection on Berberine-enhanced phosphorylation of AMPK-Thr172 and ACC-Ser79 in BAEC. BAEC were transfected with UCP2 siRNA for 24 hr, and then treated with Berberine (10 µM) for 2 hr. n = 3, *p<0.05, control versus Berberine-treated, # p<0.05, Berberine-alone versus Berberine plus UCP2 siRNA.G. Effects of adenoviral overexpression of UCP-2 on Berberine-enhanced phosphorylation of AMPK-Thr172 and ACC-Ser79 in BAEC. n = 3 *p<0.05, control versus UCP-2; #p<0.05, control verus Berberine-alone; +p<0.05 Berberine-treated versus Berberine plus UCP2.