title: ATGL-catalyzed lipolysis regulates SIRT1 to control PGC-1α/PPAR-α signaling.
abstract: Sirtuin 1 (SIRT1), an NAD(+)-dependent protein deacetylase, regulates a host of target proteins, including peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), a transcriptional coregulator that binds to numerous transcription factors in response to deacetylation to promote mitochondrial biogenesis and oxidative metabolism. Our laboratory and others have shown that adipose triglyceride lipase (ATGL) increases the activity of the nuclear receptor PPAR-α, a PGC-1α binding partner, to promote fatty acid oxidation. Fatty acids bind and activate PPAR-α; therefore, it has been presumed that fatty acids derived from ATGL-catalyzed lipolysis act as PPAR-α ligands. We provide an alternate mechanism that links ATGL to PPAR-α signaling. We show that SIRT1 deacetylase activity is positively regulated by ATGL to promote PGC-1α signaling. In addition, ATGL mediates the effects of β-adrenergic signaling on SIRT1 activity, and PGC-1α and PPAR-α target gene expression independent of changes in NAD(+). Moreover, SIRT1 is required for the induction of PGC-1α/PPAR-α target genes and oxidative metabolism in response to increased ATGL-mediated lipolysis. Taken together, this work identifies SIRT1 as a critical node that links β-adrenergic signaling and lipolysis to changes in the transcriptional regulation of oxidative metabolism.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
authors.forename: Salmaan Ahmed
authors.initials: SA
authors.lastname: Khan
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
authors.forename: Aishwarya
authors.initials: A
authors.lastname: Sathyanarayan
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
authors.forename: Mara T
authors.initials: MT
authors.lastname: Mashek
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
authors.forename: Kuok Teong
authors.initials: KT
authors.lastname: Ong
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
authors.forename: Edith E
authors.initials: EE
authors.lastname: Wollaston-Hayden
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN dmashek@umn.edu.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Mashek
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D022781:Hepatocytes / Q000378:metabolism; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D008066:Lipolysis / Q000502:physiology; D008297:Male; D051379:Mice; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D015398:Signal Transduction / Q000502:physiology*; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D000217:Acyltransferases
chemical_list: D008049:Lipase; D047493:PPAR alpha; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D056564:Sirtuin 1; D014157:Transcription Factors; C485290:Ppargc1a protein, mouse; C494445:PNPLA2 protein, mouse; D000217:Acyltransferases; C470545:Sirt1 protein, mouse