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

J. Biol. Chem., Vol. 277, Issue 24, 21489-21498, June 14, 2002

This Article Full Text Full Text (PDF) All Versions of this Article: 277/24/21489    most recent M201710200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Carmona, M. C. Articles by Giralt, M. Search for Related Content PubMed PubMed Citation Articles by Carmona, M. C. Articles by Giralt, M. Social Bookmarking                      What's this?

Mitochondrial Biogenesis and Thyroid Status Maturation in Brown Fat Require CCAAT/Enhancer-binding Protein ^*

M. Carmen Carmona, Roser Iglesias, María-Jesús Obregón^§, Gretchen J. Darlington^¶, Francesc Villarroya, and Marta Giralt

From the  Departament de Bioquímica i Biologia Molecular, Universitat de Barcelona, Barcelona E-08028, Spain, the ^§ Instituto de Investigaciones Biomédicas "Alberto Sols," Centro mixto CSIC-UAM, Madrid E-28029, Spain, and the ^¶ Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030

Brown fat differentiation in mice is fully achieved in fetuses at term and entails the acquisition of not only adipogenic but also thermogenic and oxidative mitochondrial capacities. The present study of the mice homozygous for a deletion in the gene for CCAAT/enhancer-binding protein  (C/EBP-null mice) demonstrates that C/EBP is essential for all of these processes. Developing brown fat from C/EBP-null mice showed a lack of uncoupling protein-1 expression, impaired adipogenesis, and reduced size and number of mitochondria per cell when compared with wild-type mice. Furthermore, immature mitochondrial morphology was found in brown fat, but not in liver or heart, from C/EBP-null mice. Concordantly, expression of both nuclear and mitochondrial genome-encoded genes for mitochondrial proteins was reduced in C/EBP-null brown fat, although expression of mitochondrial rRNA and mitochondrial DNA content were unaltered. Expression of nuclear respiratory factor-2, thyroid hormone nuclear receptors, and peroxisome proliferator-activated receptor  coactivator-1, was delayed in C/EBP-null brown fat. Iodothyronine 5'-deiodinase activity and thyroid hormone content were also reduced in brown fat from C/EBP-null mice, indicating for the first time a crucial role for C/EBP in controlling thyroid status in developing brown fat, which may contribute to impaired mitochondrial biogenesis and cell differentiation. When survival of C/EBP-null mice was achieved by transgenically expressing C/EBP only in the liver, a substantial recovery in brown fat differentiation was found by day 7 of postnatal age, which is associated with a compensatory overexpression of C/EBP and C/EBP.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				M. C. Carmona, K. Louche, B. Lefebvre, A. Pilon, N. Hennuyer, V. Audinot-Bouchez, C. Fievet, G. Torpier, P. Formstecher, P. Renard, et al. S 26948: a New Specific Peroxisome Proliferator Activated Receptor {gamma} Modulator With Potent Antidiabetes and Antiatherogenic Effects Diabetes, November 1, 2007; 56(11): 2797 - 2808. [Abstract] [Full Text] [PDF]

				S. Kang, L. Bajnok, K. A. Longo, R. K. Petersen, J. B. Hansen, K. Kristiansen, and O. A. MacDougald Effects of Wnt Signaling on Brown Adipocyte Differentiation and Metabolism Mediated by PGC-1{alpha} Mol. Cell. Biol., February 15, 2005; 25(4): 1272 - 1282. [Abstract] [Full Text] [PDF]

				R. Martinez-deMena and M.-J. Obregon Insulin increases the adrenergic stimulation of 5' deiodinase activity and mRNA expression in rat brown adipocytes; role of MAPK and PI3K J. Mol. Endocrinol., February 1, 2005; 34(1): 139 - 151. [Abstract] [Full Text] [PDF]

				P. Yubero, E. Hondares, M. C. Carmona, M. Rossell, F. J. Gonzalez, R. Iglesias, M. Giralt, and F. Villarroya The Developmental Regulation of Peroxisome Proliferator-Activated Receptor-{gamma} Coactivator-1{alpha} Expression in the Liver Is Partially Dissociated from the Control of Gluconeogenesis and Lipid Catabolism Endocrinology, September 1, 2004; 145(9): 4268 - 4277. [Abstract] [Full Text] [PDF]