title: Stearoyl-CoA Desaturase-1: Is It the Link between Sulfur Amino Acids and Lipid Metabolism?
abstract: An association between sulfur amino acids (methionine, cysteine, homocysteine and taurine) and lipid metabolism has been described in several experimental and population-based studies. Changes in the metabolism of these amino acids influence serum lipoprotein concentrations, although the underlying mechanisms are still poorly understood. However, recent evidence has suggested that the enzyme stearoyl-CoA desaturase-1 (SCD-1) may be the link between these two metabolic pathways. SCD-1 is a key enzyme for the synthesis of monounsaturated fatty acids. Its main substrates C16:0 and C18:0 and products palmitoleic acid (C16:1) and oleic acid (C18:1) are the most abundant fatty acids in triglycerides, cholesterol esters and membrane phospholipids. A significant suppression of SCD-1 has been observed in several animal models with disrupted sulfur amino acid metabolism, and the activity of SCD-1 is also associated with the levels of these amino acids in humans. This enzyme also appears to be involved in the etiology of metabolic syndromes because its suppression results in decreased fat deposits (regardless of food intake), improved insulin sensitivity and higher basal energy expenditure. Interestingly, this anti-obesogenic phenotype has also been described in humans and animals with sulfur amino acid disorders, which is consistent with the hypothesis that SCD-1 activity is influenced by these amino acids, in particularly cysteine, which is a strong and independent predictor of SCD-1 activity and fat storage. In this narrative review, we discuss the evidence linking sulfur amino acids, SCD-1 and lipid metabolism.
authors.affiliation: Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Prédio 43323M, Porto Alegre, RS 91501-970, Brazil. spoloni@hcpa.ufrgs.br.
authors.forename: Soraia
authors.initials: S
authors.lastname: Poloni
authors.affiliation: Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, University Medical Centre Freiburg, Mathildenstrasse 1, Freiburg 79106, Germany. henk.blom@uniklinik-freiburg.de.
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Blom
authors.affiliation: Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Prédio 43323M, Porto Alegre, RS 91501-970, Brazil. ischwartz@hcpa.ufrgs.br.|Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350 Santa Cecília, Porto Alegre, RS 90035-903, Brazil. ischwartz@hcpa.ufrgs.br.
authors.forename: Ida V D
authors.initials: IV
authors.lastname: Schwartz
keywords: SCD-1; cysteine; homocysteine; homocystinuria; lipoproteins; stearoyl CoA desaturase-1; sulfur amino acids