Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2002-11-27
pubmed:abstractText
Hormone-sensitive lipase (HSL) is presumed to be essential for lipolysis, which is defined as the mobilization of free fatty acids from adipocytes. In the present study, we investigated the effects of various lipolytic hormones on the lipolysis in adipocytes derived from mouse embryonic fibroblasts (MEF adipocytes) prepared from HSL-deficient mice (HSL-/-). HSL-/- MEF differentiated into mature adipocytes in a manner indistinguishable from that of wild-type mice. Both isoproterenol (ISO) and tumor necrosis factor (TNF)-alpha stimulated the rate of lipolysis in HSL-/- MEF adipocytes, although to a lesser extent than in wild-type cells, and these lipolytic activities were inhibited by H-89, a cAMP-dependent protein kinase inhibitor, and troglitazone, respectively. Thus, the responses of the residual lipolytic activity to lipolytic hormones and TNF-alpha were well conserved in the absence of HSL. Extracts from HSL-/- MEF adipocytes hydrolyzed triacylglycerol (TG) but not cholesterol ester, indicating that the residual lipolytic activity was mediated by another TG-specific lipase. The TG lipase activity, which was decreased in cytosolic fraction in response to ISO, was increased in fat cake fraction. Therefore, translocation of the TG lipase may explain, at least partially, the ISO-stimulated lipolysis in HSL-/- adipocytes. In conclusion, lipolysis is mediated not only by HSL but also by the non-HSL TG lipase, whose responses to lipolytic hormones are similar to those of HSL. We propose that both lipases are regulated by common mechanism of lipolysis.
pubmed:language
eng
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Chromans, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP-Dependent Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Isoproterenol, http://linkedlifedata.com/resource/pubmed/chemical/Isoquinolines, http://linkedlifedata.com/resource/pubmed/chemical/Lipase, http://linkedlifedata.com/resource/pubmed/chemical/N-(2-(4-bromocinnamylamino)ethyl)-5-..., http://linkedlifedata.com/resource/pubmed/chemical/Sterol Esterase, http://linkedlifedata.com/resource/pubmed/chemical/Sulfonamides, http://linkedlifedata.com/resource/pubmed/chemical/Thiazoles, http://linkedlifedata.com/resource/pubmed/chemical/Thiazolidinediones, http://linkedlifedata.com/resource/pubmed/chemical/Tissue Extracts, http://linkedlifedata.com/resource/pubmed/chemical/Triglycerides, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Necrosis Factor-alpha, http://linkedlifedata.com/resource/pubmed/chemical/troglitazone
pubmed:status
MEDLINE
pubmed:author
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3368-75
pubmed:dateRevised
2010-11-18
pubmed:articleTitle
Lipolysis in the absence of hormone-sensitive lipase: evidence for a common mechanism regulating distinct lipases.
pubmed:affiliation
Department of Metabolic Diseases, Faculty of Medicine, University of Tokyo, Tokyo, Japan.