title: PPARα and Sirt1 mediate erythropoietin action in increasing metabolic activity and browning of white adipocytes to protect against obesity and metabolic disorders.
abstract: Erythropoietin (EPO) has shown beneficial effects in the regulation of obesity and metabolic syndrome; however, the detailed mechanism is still largely unknown. Here, we created mice with adipocyte-specific deletion of EPO receptor. These mice exhibited obesity and decreased glucose tolerance and insulin sensitivity, especially when fed a high-fat diet. Moreover, EPO increased oxidative metabolism, fatty acid oxidation, and key metabolic genes in adipocytes and in white adipose tissue from diet-induced obese wild-type mice. Increased metabolic activity by EPO is associated with induction of brown fat-like features in white adipocytes, as demonstrated by increases in brown fat gene expression, mitochondrial content, and uncoupled respiration. Peroxisome proliferator-activated receptor (PPAR)α was found to mediate EPO activity because a PPARα antagonist impaired EPO-mediated induction of brown fat-like gene expression and uncoupled respiration. PPARα also cooperates with Sirt1 activated by EPO through modulating the NAD+ level to regulate metabolic activity. PPARα targets, including PPARγ coactivator 1α, uncoupling protein 1, and carnitine palmitoyltransferase 1α, were increased by EPO but impaired by Sirt1 knockdown. Sirt1 knockdown also attenuated adipose response to EPO. Collectively, EPO, as a novel regulator of adipose energy homeostasis via these metabolism coregulators, provides a potential therapeutic strategy to protect against obesity and metabolic disorders.
authors.affiliation: Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Teng
authors.forename: Lijun
authors.initials: L
authors.lastname: Di
authors.forename: Heather
authors.initials: H
authors.lastname: Rogers
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Kopp
authors.forename: Constance Tom
authors.initials: CT
authors.lastname: Noguchi
mesh_terms: D041721:3T3-L1 Cells; D052438:Adipocytes, White / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism; D059305:Diet, High-Fat; D004921:Erythropoietin / Q000378:metabolism* / Q000494:pharmacology; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects / Q000502:physiology; D008659:Metabolic Diseases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism*; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000378:metabolism*; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*; D000071256:Uncoupling Protein 1
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; D047493:PPAR alpha; D017467:Receptors, Erythropoietin; C000604372:Ucp1 protein, mouse; D000071256:Uncoupling Protein 1; D004921:Erythropoietin; D002334:Carnitine O-Palmitoyltransferase; D056564:Sirtuin 1