title: IL-10 gene transfer upregulates arcuate POMC and ameliorates hyperphagia, obesity and diabetes by substituting for leptin.
abstract: BACKGROUND
  Obesity and metabolic syndrome are the major risk factors for cardiovascular disease. Obesity is caused by increased food intake and/or decreased energy expenditure. Leptin potently inhibits food intake and promotes energy expenditure. These effects of leptin involve the activation of proopiomelanocortin (POMC) neurons in the hypothalamus arcuate nucleus (ARC). Disruption of leptin signaling in POMC neuron is considered one of the major causes for obesity.
  
  
  OBJECTIVE
  The present study aimed to examine whether overexpression of interleukin-10 (IL-10) could substitute for the leptin action and ameliorate obesity in leptin-deficient Lep(ob/ob) mice.
  
  
  METHODS
  Adeno-associated virus (AAV) expressing murine IL-10 (AAV-mIL-10) was injected into the skeletal muscle to overexpress IL-10 in mice. These mice were subsequently subjected to analysis of body weight, food intake, glucose metabolism and underlying mechanisms.
  
  
  RESULTS
  In Lep(ob/ob) mice, AAV-IL-10 ameliorated hyperphagia, obesity, glucose intolerance and insulin resistance, as well as attenuated tumor necrosis factor-α expression. The IL-10 treatment also improved glucose-induced insulin release. Furthermore, IL-10 treatment increased POMC mRNA expression in ARC and phosphorylation of signal transducer and activator of transcription-3 (STAT3) in ARC and white adipose tissue (WAT). In neuron-specific STAT3-null mice that exhibited obesity and hyperphagia, AAV-mIL-10 administration failed to affect food intake, body weight and phosphorylation of STAT3 in WAT.
  
  
  CONCLUSIONS
  These results demonstrate that peripheral overexpression of IL-10 induces STAT3 phosphorylation in ARC POMC neurons, and thereby ameliorates hyperphagia and obesity caused by leptin deficiency. IL-10 gene transfer may provide an effective approach for preventing progression of metabolic syndrome due to leptin resistance.
authors.affiliation: Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakata
authors.affiliation: Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Japan.|Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okada
authors.affiliation: Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Gantulga
authors.affiliation: Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okano
authors.affiliation: Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ozawa
authors.affiliation: Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Japan.|Department of Developmental Physiology, Division of Adaptation Development, National Institute for Physiological Sciences, Okazaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yada
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000473:pathology*; D004195:Disease Models, Animal; D004734:Energy Metabolism; D018014:Gene Transfer Techniques; D006963:Hyperphagia / Q000473:pathology*; D016753:Interleukin-10 / Q000378:metabolism*; D020738:Leptin; D008297:Male; D051379:Mice; D009765:Obesity / Q000473:pathology*; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: C556062:IL10 protein, mouse; D020738:Leptin; D016753:Interleukin-10; D011333:Pro-Opiomelanocortin