title: Acute aerobic exercise mediates G protein-coupled receptor kinase 2 expression in human PBMCs.
abstract: OBJECTIVE
  G protein-coupled receptor kinase 2 (GRK2), a cytosolic enzyme desensitizing G protein-couple receptors (e.g., β-adrenergic receptors [β-ARs]), is involved in regulation of hypertension, congestive heart failure, and inflammatory response. Since cellular GRK2 levels change quickly in response to exogenous/endogenous stimuli, this study examined whether GRK2 levels in human peripheral blood mononuclear cells (PBMCs) would increase during acute aerobic exercise and be associated with plasma IL-6 and cardiorespiratory fitness levels.
  
  
  METHODS
  Eighteen subjects (8 men and 10 women), ages 18 to 30 years, were recruited to perform a 30-minute bout of acute aerobic exercise at 75% VO2max.
  
  
  RESULTS
  Our results demonstrated that women exhibited significantly greater exercise-induced GRK2 expression in PBMCs compared to men. IL-6 modulation is independent of GRK2 expression. Furthermore, the percent change in GRK2 expression was negatively correlated with cardiorespiratory fitness levels (relative VO2max), but not plasma IL-6.
  
  
  CONCLUSIONS
  Acute aerobic exercise induces a greater GRK2 expression in women than men, while increased cardiorespiratory fitness is associated with exercise-induced GRK2 expression in PBMCs. Gender could be a contributor to regulate this GRK2 responsiveness to acute aerobic exercise.
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA. Electronic address: chuang5@fau.edu.
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Huang
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA; Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Slusher
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Whitehurst
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Wells
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA; University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Mock
authors.affiliation: Exercise Biochemistry Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Maharaj
authors.affiliation: Department of Biomedical Science, College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Shibata
mesh_terms: D000293:Adolescent; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D054769:G-Protein-Coupled Receptor Kinase 2 / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000201:enzymology*; D008297:Male; D012727:Sex Characteristics
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; C496567:GRK2 protein, human; D054769:G-Protein-Coupled Receptor Kinase 2
keywords: Exercise; Fitness; G protein-coupled receptor kinase 2; Gender; IL-6; Inflammation