Document Detail

Contribution of adipose triglyceride lipase and hormone-sensitive lipase to lipolysis in hMADS adipocytes.
MedLine Citation:
PMID:  19433586     Owner:  NLM     Status:  MEDLINE    
Lipolysis is the catabolic pathway by which triglycerides are hydrolyzed into fatty acids. Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) have the capacity to hydrolyze in vitro the first ester bond of triglycerides, but their respective contributions to whole cell lipolysis in human adipocytes is unclear. Here, we have investigated the roles of HSL, ATGL, and its coactivator CGI-58 in basal and forskolin-stimulated lipolysis in a human white adipocyte model, the hMADS cells. The hMADS adipocytes express the various components of fatty acid metabolism and show lipolytic capacity similar to primary cultured adipocytes. We show that lipolysis and fatty acid esterification are tightly coupled except in conditions of stimulated lipolysis. Immunocytochemistry experiments revealed that acute forskolin treatment promotes HSL translocation from the cytosol to small lipid droplets and redistribution of ATGL from the cytosol and large lipid droplets to small lipid droplets, resulting in enriched colocalization of the two lipases. HSL or ATGL overexpression resulted in increased triglyceride-specific hydrolase capacity, but only ATGL overexpression increased whole cell lipolysis. HSL silencing had no effect on basal lipolysis and only partially reduced forskolin-stimulated lipolysis. Conversely, silencing of ATGL or CGI-58 significantly reduced basal lipolysis and essentially abolished forskolin-stimulated lipolysis. Altogether, these results suggest that ATGL/CGI-58 acts independently of HSL and precedes its action in the sequential hydrolysis of triglycerides in human hMADS adipocytes.
Véronic Bezaire; Aline Mairal; Carole Ribet; Corinne Lefort; Amandine Girousse; Johan Jocken; Jurga Laurencikiene; Rodica Anesia; Anne-Marie Rodriguez; Mikael Ryden; Britta M Stenson; Christian Dani; Gérard Ailhaud; Peter Arner; Dominique Langin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-05-11
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  284     ISSN:  1083-351X     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-06-29     Completed Date:  2009-10-27     Revised Date:  2010-09-24    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  18282-91     Citation Subset:  IM    
INSERM U858, Laboratoire de Recherches sur les Obésités, F-31432 Toulouse, France.
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MeSH Terms
1-Acylglycerol-3-Phosphate O-Acyltransferase
Adipocytes / cytology,  drug effects,  enzymology*
Cells, Cultured
Cytosol / enzymology
Energy Metabolism / physiology*
Esterification / physiology
Fatty Acids / metabolism
Forskolin / pharmacology
Green Fluorescent Proteins / genetics
Lipase / genetics,  metabolism*
Lipolysis / physiology*
RNA, Small Interfering
Sterol Esterase / genetics,  metabolism*
Reg. No./Substance:
0/Fatty Acids; 0/RNA, Small Interfering; 147336-22-9/Green Fluorescent Proteins; 66428-89-5/Forskolin; EC O-Acyltransferase; EC protein, human; EC Esterase; EC; EC protein, human

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