title: AMP kinase regulation of sugar transport in brain capillary endothelial cells during acute metabolic stress.
abstract: AMP-dependent kinase (AMPK) and GLUT1-mediated sugar transport in blood-brain barrier endothelial cells are activated during acute cellular metabolic stress. Using murine brain microvasculature endothelium bEnd.3 cells, we show that AMPK phosphorylation and stimulation of 3-O-methylglucose transport by the AMPK agonist AICAR are inhibited in a dose-dependent manner by the AMPK antagonist Compound C. AMPK α1- or AMPK α2-knockdown by RNA interference or AMPK inhibition by Compound C reduces AMPK phosphorylation and 3-O-methylglucose transport stimulation induced by cellular glucose-depletion, by potassium cyanide (KCN), or by carbonyl cyanide-p-trifluoromethoxy-phenylhydrazone (FCCP). Cell surface biotinylation studies reveal that plasma membrane GLUT1 levels are increased two- to threefold by cellular glucose depletion, AICAR or KCN treatment, and that these increases are prevented by Compound C and by AMPK α1- or α2-knockdown. These results support the hypothesis that AMPK activation in blood-brain barrier-derived endothelial cells directs the trafficking of GLUT1 intracellular pools to the plasma membrane, thereby increasing endothelial sugar transport capacity.
authors: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, USA.
authors: Anthony J
authors: AJ
authors: Cura
authors: Anthony
authors: A
authors: Carruthers
mesh_terms: D019325:3-O-Methylglucose / Q000493:pharmacokinetics*; D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000201:enzymology*; D002461:Cell Line, Transformed; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D013312:Stress, Physiological / Q000502:physiology*
chemical_list: D021122:Protein Subunits; D019325:3-O-Methylglucose; C548179:Prkaa1 protein, mouse; C534978:Prkaa2 protein, mouse; D055372:AMP-Activated Protein Kinases