title: GSK3β-dependent inhibition of AMPK potentiates activation of neutrophils and macrophages and enhances severity of acute lung injury.
abstract: Although AMP-activated protein kinase (AMPK) is involved in regulating carbohydrate and lipid metabolism, activated AMPK also plays an anti-inflammatory role in many cell populations. However, despite the ability of AMPK activation to diminish the severity of inflammatory responses, previous studies have found that AMPK activity is diminished in LPS-treated neutrophils and also in lungs of mice with LPS-induced acute lung injury (ALI). Since GSK3β participates in regulating AMPK activity, we examined potential roles for GSK3β in modulating LPS-induced activation of neutrophils and macrophages and in influencing severity of ALI. We found that GSK3β-dependent phosphorylation of T479-AMPK was associated with pT172 dephosphorylation and inactivation of AMPK following TLR4 engagement. GSK3β inhibitors BIO (6-bromoindirubin-3'-oxime), SB216763, or siRNA knockdown of GSK3β, but not the PI3K/AKT inhibitor LY294002, prevented Thr172-AMPK dephosphorylation. Exposure to LPS resulted in rapid binding between IKKβ and AMPKα, and phosphorylation of S485-AMPK by IKKβ. These results suggest that IKKβ-dependent phosphorylation of S485-AMPK was an essential step in subsequent phosphorylation and inactivation AMPK by GSK3β. Inhibition of GSK3β activity delayed IκBα degradation and diminished expression of the proinflammatory TNF-α in LPS-stimulated neutrophils and macrophages. In vivo, inhibition of GSK3β decreased the severity of LPS-induced lung injury as assessed by development of pulmonary edema, production of TNF-α and MIP-2, and release of the alarmins HMGB1 and histone 3 in the lungs. These results show that inhibition of AMPK by GSK3β plays an important contributory role in enhancing LPS-induced inflammatory responses, including worsening the severity of ALI.
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; Division of Infectious Diseases, Korea University Ansan Hospital, Ansan, Korea;
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Park
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
authors.forename: Shaoning
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
authors.forename: Yanping
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama;
authors.forename: Gene P
authors.initials: GP
authors.lastname: Siegal
authors.affiliation: University of Michigan Medical School, Ann Arbor, Michigan; and.
authors.forename: Ken
authors.initials: K
authors.lastname: Inoki
authors.affiliation: Office of the Dean, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
authors.forename: Edward
authors.initials: E
authors.lastname: Abraham
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; zmijewsk@uab.edu.
authors.forename: Jaroslaw W
authors.initials: JW
authors.lastname: Zmijewski
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D055371:Acute Lung Injury / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D000818:Animals; D002460:Cell Line; D054426:Chemokine CXCL2 / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D024243:HMGB1 Protein / Q000378:metabolism; D051550:I-kappa B Kinase / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000633:toxicity; D008262:Macrophage Activation; D008264:Macrophages / Q000201:enzymology* / Q000473:pathology; D008301:Maleimides / Q000494:pharmacology; D051379:Mice; D009025:Morpholines / Q000494:pharmacology; D018375:Neutrophil Activation; D009504:Neutrophils / Q000201:enzymology* / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D011654:Pulmonary Edema / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D054426:Chemokine CXCL2; D002867:Chromones; C404915:Cxcl2 protein, mouse; D004791:Enzyme Inhibitors; D024243:HMGB1 Protein; C582808:HMGB1 protein, mouse; D007211:Indoles; D008070:Lipopolysaccharides; D008301:Maleimides; D009025:Morpholines; C417521:SB 216763; D014409:Tumor Necrosis Factor-alpha; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D051550:I-kappa B Kinase; D038362:Glycogen Synthase Kinase 3; D055372:AMP-Activated Protein Kinases
keywords: AMPK; GSK3β; IKK; acute lung injury; inflammation