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

J. Biol. Chem., Vol. 281, Issue 42, 31894-31908, October 20, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/42/31894    most recent M606114200v1 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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ukropec, J. Articles by Kozak, L. P. Search for Related Content PubMed PubMed Citation Articles by Ukropec, J. Articles by Kozak, L. P. Social Bookmarking                      What's this?

UCP1-independent Thermogenesis in White Adipose Tissue of Cold-acclimated Ucp1^-/- Mice^*

From the Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana 70808

Apart from UCP1-based nonshivering thermogenesis in brown adipocytes, the identity of thermogenic mechanisms that can be activated to reduce a positive energy balance is largely unknown. To identify potentially useful mechanisms, we have analyzed physiological and molecular mechanisms that enable mice, genetically deficient in UCP1 and sensitive to acute exposure to the cold at 4 °C, to adapt to long term exposure at 4 °C. UCP1-deficient mice that can adapt to the cold have increased oxygen consumption and show increased oxidation of both fat and glucose as indicated from serum metabolite levels and liver glycogen content. Enhanced energy metabolism in inguinal fat was also indicated by increased oxygen consumption and fat oxidation in tissue suspensions and increased AMP kinase activity in dissected tissues. Analysis of gene expression in skeletal muscle showed surprisingly little change between cold-adapted Ucp1^+/+ and Ucp1^-/- mice, whereas in inguinal fat a robust induction occurred for type 2 deiodinase, sarcoendoplasmic reticulum Ca²⁺-ATPase, mitochondrial glycerol 3-phosphate dehydrogenase, PGC1, CoxII, and mitochondrial DNA content. Western blot analysis showed an induction of total phospholamban and its phosphorylated form in inguinal fat and other white fat depots, but no induction was apparent in muscle. We conclude that alternative thermogenic mechanisms, based in part upon the enhanced capacity for ion and substrate cycling associated with brown adipocytes in white fat depots, are induced in UCP1-deficient mice by gradual cold adaptation.

Received for publication, June 26, 2006 , and in revised form, July 27, 2006.

^* This work was supported by National Institutes of Health Grant R01HD08431. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ Both authors contributed equally to this work.

² Present address: Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06 Bratislava, Slovak Republic.

³ Present address: Virginia Polytechnic Institute and State University Department of Human Nutrition, Foods and Exercise, Corporate Research Center, Bldg. 15, Rm. 1119, 1880 Pratt Dr., Blacksburg, VA 24061.

⁴ To whom correspondence should be addressed: Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808. Tel.: 225-763-2771; Fax: 225-763-0273; E-mail: kozaklp{at}pbrc.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				B. A. Adams, S. L. Gray, E. R. Isaac, A. C. Bianco, A. J. Vidal-Puig, and N. M. Sherwood Feeding and Metabolism in Mice Lacking Pituitary Adenylate Cyclase-Activating Polypeptide Endocrinology, April 1, 2008; 149(4): 1571 - 1580. [Abstract] [Full Text] [PDF]

				B. A. Henry, F. R. Dunshea, M. Gould, and I. J. Clarke Profiling Postprandial Thermogenesis in Muscle and Fat of Sheep and the Central Effect of Leptin Administration Endocrinology, April 1, 2008; 149(4): 2019 - 2026. [Abstract] [Full Text] [PDF]

				J. Sonoda, I. R. Mehl, L.-W. Chong, R. R. Nofsinger, and R. M. Evans PGC-1beta controls mitochondrial metabolism to modulate circadian activity, adaptive thermogenesis, and hepatic steatosis PNAS, March 20, 2007; 104(12): 5223 - 5228. [Abstract] [Full Text] [PDF]