HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 292/6/E1847    most recent 00040.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Rydén, M. Articles by Arner, P. Search for Related Content PubMed PubMed Citation Articles by Rydén, M. Articles by Arner, P.

Comparative studies of the role of hormone-sensitive lipase and adipose triglyceride lipase in human fat cell lipolysis

Departments of ¹Medicine and ⁶Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden; ²Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands; ³Institut National de la Santé et de la Recherche Médicale, U586, Unité de Recherches sur les Obésités, Toulouse; ⁴Université Paul Sabatier, Institut Louis Bugnard, Toulouse; and ⁵Centre Hospitalier Universitaire de Toulouse, Biochimie, Institut Fédératif de Biologie de Purpan, Toulouse, France

Submitted 16 January 2007 ; accepted in final form 22 February 2007

Hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) regulate adipocyte lipolysis in rodents. The purpose of this study was to compare the roles of these lipases for lipolysis in human adipocytes. Subcutaneous adipose tissue was investigated. HSL and ATGL protein expression were related to lipolysis in isolated mature fat cells. ATGL or HSL were knocked down by RNA interference (RNAi) or selectively inhibited, and effects on lipolysis were studied in differentiated preadipocytes or adipocytes derived from human mesenchymal stem cells (hMSC). Subjects were all women. There were 12 lean controls, 8 lean with polycystic ovary syndrome (PCOS), and 27 otherwise healthy obese subjects. We found that norepinephrine-induced lipolysis was positively correlated with HSL protein levels (P < 0.0001) but not with ATGL protein. Women with PCOS or obesity had significantly decreased norepinephrine-induced lipolysis and HSL protein expression but no change in ATGL protein expression. HSL knock down by RNAi reduced basal and catecholamine-induced lipolysis. Knock down of ATGL decreased basal lipolysis but did not change catecholamine-stimulated lipolysis. Treatment of hMSC with a selective HSL inhibitor during and/or after differentiation in adipocytes reduced basal lipolysis by 50%, but stimulated lipolysis was inhibited completely. In contrast to findings in rodents, ATGL is of less importance than HSL in regulating catecholamine-induced lipolysis and cannot replace HSL when this enzyme is continuously inhibited. However, both lipases regulate basal lipolysis in human adipocytes. ATGL expression, unlike HSL, is not influenced by obesity or PCOS.

glycerol; ribonucleic acid interference; lipase; protein; obesity

This article has been cited by other articles:

				D. L. Brasaemle Thematic review series: Adipocyte Biology. The perilipin family of structural lipid droplet proteins: stabilization of lipid droplets and control of lipolysis J. Lipid Res., December 1, 2007; 48(12): 2547 - 2559. [Abstract] [Full Text] [PDF]

				G. R. Steinberg, B. E. Kemp, and M. J. Watt Adipocyte triglyceride lipase expression in human obesity Am J Physiol Endocrinol Metab, October 1, 2007; 293(4): E958 - E964. [Abstract] [Full Text] [PDF]