title: Acute Exercise Decreases Tribbles Homolog 3 Protein Levels in the Hypothalamus of Obese Rats.
abstract: OBJECTIVE
  This study aims to evaluate the effects of acute exercise on tribbles homolog 3 (TRB3) protein levels and on the interaction between TRB3 and Akt proteins in the hypothalamus of obese rats. In addition, we evaluated the relationship between TRB3 and endoplasmic reticulum (ER) stress and verified whether an acute exercise session influences them.
  
  
  METHODS
  In the first part of the study, the rats were divided into three groups: control (lean), fed standard rodent chow; DIO, fed a high-fat diet; and DIO-EXE, fed a high-fat diet and submitted to a swimming acute exercise protocol. In the second part of the study, we used three other groups: control (lean) group receiving an intracerebroventricular (i.c.v.) infusion of vehicle, lean group receiving an i.c.v. infusion of thapsigargin, and lean group receiving an i.c.v. infusion of thapsigargin and performing an acute exercise session. Four hours after the exercise session, food intake was measured, and the hypothalamus was dissected and separated for subsequent protein analysis by immunoblotting and real-time polymerase chain reaction.
  
  
  RESULTS
  The acute exercise session reduced TRB3 protein levels, disrupted the interaction between TRB3 and Akt proteins, increased the phosphorylation of Foxo1, and restored the anorexigenic effects of insulin on the hypothalamus of DIO rats. Interestingly, the suppressive effects of acute exercise on TRB3 protein levels may be related, at least in part, to decreased ER stress (evaluated though pancreatic ER kinase phosphorylation and C/EBP homologous protein levels) in the hypothalamus.
  
  
  CONCLUSIONS
  Exercise-mediated reduction of hypothalamic TRB3 protein levels may be associated with reduction of ER stress. These data provide a new mechanism by which an acute exercise session improves insulin sensitivity in the hypothalamus and restores food intake control in obesity.
authors.affiliation: 1Laboratory of Molecular Biology of Exercise and Center for Biological Assays, Center for Research in Sport Science, School of Applied Science, University of Campinas, Limeira, São Paulo, BRAZIL; 2Laboratory of Exercise Biochemistry and Physiology, Health Science Unit, University of Extremo Sul Catarinense, Criciúma, Santa Catarina, BRAZIL; 3School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, BRAZIL; and 4São Paulo University State, Rio Claro, São Paulo, BRAZIL.
authors.forename: Barbara De Almeira
authors.initials: Bde A
authors.lastname: Rodrigues
authors.forename: Luciana Santos Souza
authors.initials: LS
authors.lastname: Pauli
authors.forename: Claudio Teodoro
authors.initials: CT
authors.lastname: DE Souza
authors.forename: Adelino Sanchez Ramos
authors.initials: AS
authors.lastname: DA Silva
authors.forename: Dennys Esper Correa
authors.initials: DE
authors.lastname: Cintra
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Marinho
authors.forename: Leandro Pereira
authors.initials: LP
authors.lastname: DE Moura
authors.forename: Eloize Cristina Chiarreotto
authors.initials: EC
authors.lastname: Ropelle
authors.forename: José Diego
authors.initials: JD
authors.lastname: Botezelli
authors.forename: Eduardo Rochete
authors.initials: ER
authors.lastname: Ropelle
authors.forename: José Rodrigo
authors.initials: JR
authors.lastname: Pauli
mesh_terms: D000818:Animals; D007031:Hypothalamus / Q000378:metabolism*; D009765:Obesity / Q000097:blood*; D010805:Physical Conditioning, Animal; D005082:Physical Exertion / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000097:blood; D051057:Proto-Oncogene Proteins c-akt / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar
chemical_list: C502443:Trib3 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt