title: IKKε is key to induction of insulin resistance in the hypothalamus, and its inhibition reverses obesity.
abstract: IKK epsilon (IKKε) is induced by the activation of nuclear factor-κB (NF-κB). Whole-body IKKε knockout mice on a high-fat diet (HFD) were protected from insulin resistance and showed altered energy balance. We demonstrate that IKKε is expressed in neurons and is upregulated in the hypothalamus of obese mice, contributing to insulin and leptin resistance. Blocking IKKε in the hypothalamus of obese mice with CAYMAN10576 or small interfering RNA decreased NF-κB activation in this tissue, relieving the inflammatory environment. Inhibition of IKKε activity, but not TBK1, reduced IRS-1(Ser307) phosphorylation and insulin and leptin resistance by an improvement of the IR/IRS-1/Akt and JAK2/STAT3 pathways in the hypothalamus. These improvements were independent of body weight and food intake. Increased insulin and leptin action/signaling in the hypothalamus may contribute to a decrease in adiposity and hypophagia and an enhancement of energy expenditure accompanied by lower NPY and increased POMC mRNA levels. Improvement of hypothalamic insulin action decreases fasting glycemia, glycemia after pyruvate injection, and PEPCK protein expression in the liver of HFD-fed and db/db mice, suggesting a reduction in hepatic glucose production. We suggest that IKKε may be a key inflammatory mediator in the hypothalamus of obese mice, and its hypothalamic inhibition improves energy and glucose metabolism.
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Laís
authors.initials: L
authors.lastname: Weissmann
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Paula G F
authors.initials: PG
authors.lastname: Quaresma
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Andressa C
authors.initials: AC
authors.lastname: Santos
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Alexandre H B
authors.initials: AH
authors.lastname: de Matos
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Vínicius D'Ávila Bittencourt
authors.initials: VD
authors.lastname: Pascoal
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Tamires M
authors.initials: TM
authors.lastname: Zanotto
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Gisele
authors.initials: G
authors.lastname: Castro
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Dioze
authors.initials: D
authors.lastname: Guadagnini
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Joelcimar Martins
authors.initials: JM
authors.lastname: da Silva
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Licio A
authors.initials: LA
authors.lastname: Velloso
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Jackson C
authors.initials: JC
authors.lastname: Bittencourt
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Iscia
authors.initials: I
authors.lastname: Lopes-Cendes
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Mario J A
authors.initials: MJ
authors.lastname: Saad
authors.affiliation: Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil School of Applied Sciences, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil pprada@fcm.unicamp.br.
authors.forename: Patricia O
authors.initials: PO
authors.lastname: Prada
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D059305:Diet, High-Fat; D007031:Hypothalamus / Q000378:metabolism*; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008820:Mice, Obese; D009474:Neurons / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction / Q000502:physiology; D015854:Up-Regulation
chemical_list: D007328:Insulin; D020738:Leptin; D051550:I-kappa B Kinase