title: Enhanced activation of cellular AMPK by dual-small molecule treatment: AICAR and A769662.
abstract: AMP-activated protein kinase (AMPK) is a key cellular energy sensor and regulator of metabolic homeostasis. Activation of AMPK provides beneficial outcomes in fighting against metabolic disorders such as insulin resistance and type 2 diabetes. Currently, there is no allosteric AMPK activator available for the treatment of metabolic diseases, and limited compounds are available to robustly stimulate cellular/tissue AMPK in a specific manner. Here we investigated whether simultaneous administration of two different pharmacological AMPK activators, which bind and act on different sites, would result in an additive or synergistic effect on AMPK and its downstream signaling and physiological events in intact cells. We observed that cotreating primary hepatocytes with the AMP mimetic 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) and a low dose (1 μM) of the allosteric activator A769662 produced a synergistic effect on AMPK Thr172 phosphorylation and catalytic activity, which was associated with a more profound increase/decrease in phosphorylation of downstream AMPK targets and inhibition of hepatic lipogenesis compared with single-compound treatment. Mechanistically, we found that cotreatment does not stimulate LKB1, upstream kinase for AMPK, but it protects against dephosphorylation of Thr172 phosphorylation by protein phosphatase PP2Cα in an additive manner in a cell-free assay. Collectively, we demonstrate that AICAR sensitizes the effect of A769662 and promotes AMPK activity and its downstream events. The study demonstrates the feasibility of promoting AMPK activity by using two activators with distinct modes of action in order to achieve a greater activation of AMPK and downstream signaling.
authors.affiliation: Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland;
authors.forename: Serge
authors.initials: S
authors.lastname: Ducommun
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Ford
authors.forename: Laurent
authors.initials: L
authors.lastname: Bultot
authors.forename: Maria
authors.initials: M
authors.lastname: Deak
authors.forename: Luc
authors.initials: L
authors.lastname: Bertrand
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Kemp
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Steinberg
authors.forename: Kei
authors.initials: K
authors.lastname: Sakamoto
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000494:Allosteric Regulation / Q000187:drug effects; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001713:Biphenyl Compounds; D002460:Cell Line; D002478:Cells, Cultured; D020536:Enzyme Activators / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D050155:Lipogenesis / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D032446:Myoblasts / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021122:Protein Subunits / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D011753:Pyrones / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012265:Ribonucleotides / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D001713:Biphenyl Compounds; D020536:Enzyme Activators; D007004:Hypoglycemic Agents; D021122:Protein Subunits; D011753:Pyrones; D011994:Recombinant Proteins; D012265:Ribonucleotides; D013876:Thiophenes; D000620:Aminoimidazole Carboxamide; C554549:Prkab1 protein, mouse; D055372:AMP-Activated Protein Kinases; C031143:AICA ribonucleotide; D005947:Glucose; C512408:4-hydroxy-3-(4-(2-hydroxyphenyl)phenyl)-6-oxo-7H-thieno(2,3-b)pyridine-5-carbonitrile
keywords: 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside; A769662; AMP-activated protein kinase; LKB1; lipogenesis