title: Inactivation of hypothalamic FAS protects mice from diet-induced obesity and inflammation.
abstract: Obesity promotes insulin resistance and chronic inflammation. Disrupting any of several distinct steps in lipid synthesis decreases adiposity, but it is unclear if this approach coordinately corrects the environment that propagates metabolic disease. We tested the hypothesis that inactivation of FAS in the hypothalamus prevents diet-induced obesity and systemic inflammation. Ten weeks of high-fat feeding to mice with inactivation of FAS (FASKO) limited to the hypothalamus and pancreatic beta cells protected them from diet-induced obesity. Though high-fat fed FASKO mice had no beta-cell phenotype, they were hypophagic and hypermetabolic, and they had increased insulin sensitivity at the liver but not the periphery as demonstrated by hyperinsulinemic-euglycemic clamps, and biochemically by increased phosphorylated Akt, glycogen synthase kinase-3beta, and FOXO1 compared with wild-type mice. High-fat fed FASKO mice had decreased excretion of urinary isoprostanes, suggesting less oxidative stress and blunted tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) responses to endotoxin, suggesting less systemic inflammation. Pair-feeding studies demonstrated that these beneficial effects were dependent on central FAS disruption and not merely a consequence of decreased adiposity. Thus, inducing central FAS deficiency may be a valuable integrative strategy for treating several components of the metabolic syndrome, in part by correcting hepatic insulin resistance and suppressing inflammation.
authors.affiliation: Department of Medicine, Division of Endocrinology, Metabolism & Lipid Research, Washington University School of Medicine in St. Louis, MO 63110, USA.
authors.forename: Manu V
authors.initials: MV
authors.lastname: Chakravarthy
authors.forename: Yimin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Li
authors.initials: L
authors.lastname: Yin
authors.forename: Trey
authors.initials: T
authors.lastname: Coleman
authors.forename: Kirk L
authors.initials: KL
authors.lastname: Pappan
authors.forename: Connie A
authors.initials: CA
authors.lastname: Marshall
authors.forename: Michael L
authors.initials: ML
authors.lastname: McDaniel
authors.forename: Clay F
authors.initials: CF
authors.lastname: Semenkovich
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage; D054890:Fatty Acid Synthase, Type I / Q000172:deficiency* / Q000235:genetics; D005234:Fatty Liver / Q000201:enzymology / Q000517:prevention & control; D005260:Female; D005947:Glucose / Q000378:metabolism; D006706:Homeostasis; D007031:Hypothalamus / Q000201:enzymology*; D066298:In Vitro Techniques; D007249:Inflammation / Q000201:enzymology / Q000209:etiology / Q000517:prevention & control*; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009765:Obesity / Q000201:enzymology / Q000209:etiology / Q000517:prevention & control*; D018384:Oxidative Stress; D015430:Weight Gain
chemical_list: D004041:Dietary Fats; D007328:Insulin; D054890:Fatty Acid Synthase, Type I; D005947:Glucose