title: Adipocyte lipolysis and insulin resistance.
abstract: Obesity-induced insulin resistance is a major risk factor for the development of type 2 diabetes. Basal fat cell lipolysis (i.e., fat cell triacylglycerol breakdown into fatty acids and glycerol in the absence of stimulatory factors) is elevated during obesity and is closely associated with insulin resistance. Inhibition of adipocyte lipolysis may therefore be a promising therapeutic strategy for treating insulin resistance and preventing obesity-associated type 2 diabetes. In this review, we explore the relationship between adipose lipolysis and insulin sensitivity. After providing an overview of the components of fat cell lipolytic machinery, we describe the hypotheses that may support the causality between lipolysis and insulin resistance. Excessive circulating fatty acids may ectopically accumulate in insulin-sensitive tissues and impair insulin action. Increased basal lipolysis may also modify the secretory profile of adipose tissue, influencing whole body insulin sensitivity. Finally, excessive fatty acid release may also worsen adipose tissue inflammation, a well-known parameter contributing to insulin resistance. Partial genetic or pharmacologic inhibition of fat cell lipases in mice as well as short term clinical trials using antilipolytic drugs in humans support the benefit of fat cell lipolysis inhibition on systemic insulin sensitivity and glucose metabolism, which occurs without an increase of fat mass. Modulation of fatty acid fluxes and, putatively, of fat cell secretory pattern may explain the amelioration of insulin sensitivity whereas changes in adipose tissue immune response do not seem involved.
authors.affiliation: INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, UMR1048, Paul Sabatier University, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Morigny
authors.affiliation: INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, UMR1048, Paul Sabatier University, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Houssier
authors.affiliation: INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, UMR1048, Paul Sabatier University, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Mouisel
authors.affiliation: INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, UMR1048, Paul Sabatier University, France; Toulouse University Hospitals, Department of Clinical Biochemistry, Toulouse, France. Electronic address: dominique.langin@inserm.fr.
authors.forename: Dominique
authors.initials: D
authors.lastname: Langin
mesh_terms: D017667:Adipocytes / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007333:Insulin Resistance; D008049:Lipase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008066:Lipolysis; D051379:Mice; D009765:Obesity / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology
chemical_list: D008049:Lipase
keywords: Antilipolytic drugs; Fat cell; Insulin resistance; Lipase; Lipolysis; Obesity