title: A role for skeletal muscle stearoyl-CoA desaturase 1 in control of thermogenesis.
abstract: An enhanced metabolic efficiency for accelerating the recovery of fat mass (or catch-up fat) is a characteristic feature of body weight regulation after weight loss or growth retardation and is the outcome of an "adipose-specific" suppression of thermogenesis, i.e., a feedback control system in which signals from the depleted adipose tissue fat stores exert a suppressive effect on thermogenesis. Using a previously described rat model of semistarvation-refeeding in which catch-up fat results from suppressed thermogenesis per se, we report here that the gene expression of stearoyl-coenzyme A desaturase 1 (SCD1) is elevated in skeletal muscle after 2 wk of semistarvation and remains elevated in parallel to the phase of suppressed thermogenesis favoring catch-up fat during refeeding. These elevations in the SCD1 transcript are skeletal muscle specific and are associated with elevations in microsomal Delta9 desaturase enzyme activity, in the Delta9 desaturation index, and in the relative content of SCD1-derived monounsaturates in several lipid fractions extracted from skeletal muscle. An elevated skeletal muscle SCD1, by desaturating the products of de novo lipogenesis and diverting them away from mitochondrial oxidation, would inhibit substrate cycling between de novo lipogenesis and lipid oxidation, thereby leading to a state of suppressed thermogenesis that regulates the body's fat stores.
authors.affiliation: Division of Physiology, Department of Medicine, Faculty of Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland.
authors.forename: Davide
authors.initials: D
authors.lastname: Mainieri
authors.forename: Serge
authors.initials: S
authors.lastname: Summermatter
authors.forename: Josiane
authors.initials: J
authors.lastname: Seydoux
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Montani
authors.forename: Sandro
authors.initials: S
authors.lastname: Rusconi
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Russell
authors.forename: Olivier
authors.initials: O
authors.lastname: Boss
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Buchala
authors.forename: Abdul G
authors.initials: AG
authors.lastname: Dulloo
mesh_terms: D000818:Animals; D044943:Fatty Acid Desaturases / Q000235:genetics; D025461:Feedback, Physiological; D005786:Gene Expression Regulation / Q000502:physiology; D008055:Lipids / Q000032:analysis; D050155:Lipogenesis; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000502:physiology; D051381:Rats; D013217:Starvation; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000502:physiology*; D022722:Thermogenesis
chemical_list: D008055:Lipids; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C029627:delta-9 fatty acid desaturase