Specific elevation of transcript levels of particular protein subtypes induced in brown adipose tissue by cold exposure

Faculty of Pharmaceutical Sciences, University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan
Biochimica et Biophysica Acta (Impact Factor: 4.66). 05/2000; 1457(3):263-272. DOI: 10.1016/S0005-2728(00)00107-9


To understand the difference in metabolic flow in rat brown adipose tissue (BAT) from that in white adipose tissue (WAT) at the molecular level, we examined the steady-state transcript levels of 39 proteins in both adipose tissues with and without cold exposure by Northern blot analysis. In addition to the transcript levels of uncoupling protein isoforms, those of proteins involved in the transport and catabolism of fatty acids and glucose in BAT were elevated by cold exposure, suggesting the stimulation of utilization of fatty acids and glucose as fuels in BAT. As to these changes, the muscle-type subtypes were remarkable; and therefore, they were suggested to be responsible for the cold exposure-induced acceleration of energy expenditure in BAT. Furthermore, of the isoforms of β-adrenergic receptor (β-AR) and CCAAT enhancer binding protein (C/EBP), transcript levels of β1-AR and C/EBPβ in BAT were increased by the cold exposure. Possible roles of these proteins in energy metabolism in BAT were discussed.

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Available from: Takiko Daikoku
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    • "In BAT, the transcript levels of Fabp3 and Cpt1b but not Acadm and Acadl are elevated by cold exposure [13]. These results suggest that regulation of Fabp3 and Cpt1b expression is the rate-limiting step in FAO, and the constitutive expression of Acadm and Acadl is sufficient to enhance b-oxidation in BAT. "
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    ABSTRACT: Cold exposure and β3-adrenergic receptor agonist (CL316,243) treatment induce the production of beige cells, which express brown adipocytes(BA)-specific UCP1 protein, in white adipose tissue (WAT). It remains unclear whether the beige cells, which have different gene expression patterns from BA, express BA-characteristic fatty acid oxidation (FAO) proteins. Here we found that 5-day cold exposure and CL316,243 treatment of WAT, but not CL316,243 treatment of primary adipocytes of C57BL/6J mice, increased mRNA levels of BA-characteristic FAO proteins. These results suggest that BA-characteristic FAO proteins are induced in beige cells in a different pathway from UCP1.
    Preview · Article · Oct 2013 · Biochemical and Biophysical Research Communications
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    • "In most previous reports concerning cold exposure, the period of exposure was short, being several hours to weeks (Puigserver et al. 1998; Guardiola-Diaz et al. 1999; Daikoku et al. 2000; Yu et al. 2002; Goetzman et al. 2005). The expression levels of many proteins including PPARa ⁄ c dizzily changed during several weeks of cold exposure (Guardiola-Diaz et al. 1999). "
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    ABSTRACT: Peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the nuclear receptor family, regulating fatty acid degradation in many organs. Two-dimensional SDS-PAGE of brown adipose tissue (BAT) from PPARalpha-null mice produced a higher-density spot. Proteomic analysis indicated that the protein was pyruvate dehydrogenase beta (PDHbeta). To observe PDHbeta regulation in BAT, the organ was stimulated by long-term cold exposure, and the activities of associated enzymes were investigated. Histological and biochemical analyses of BAT showed a significant decrease in the triglyceride content in wild-type mice and some degree of decrease in PPARalpha-null mice on cold exposure. Analyses of molecules related to glucose metabolism showed that the expression of PDHbeta is under PPARalpha-specific regulation, and that glucose degradation ability may decrease on cold exposure. In contrast, analyses of molecules related to fatty acid metabolism showed that numerous PPARalpha/gamma target molecules are induced on cold exposure, and that fatty acid degradation ability in wild-type mice is markedly enhanced and also increases to same degree in PPARalpha-null mice on cold exposure. Thus, this study proposes novel and multiple roles of PPARalpha in BAT.
    Full-text · Article · Dec 2009 · Genes to Cells
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    • "Under these conditions, up-regulation of UCP1 is well known to enable effective thermogenesis in BAT. As mentioned above, our previous studies indicated that certain genes encoding metabolic proteins, especially their subtypes known to be significantly expressed in heart/skeletal muscle, are up-regulated in the BAT of cold-exposed animals [7] [8]. Essentially the same conclusion as ours was also obtained by Adams et al. [9]. "
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    ABSTRACT: To identify genes whose expression in brown adipose tissue (BAT) is up- or down-regulated in cold-exposed rats, we performed microarray analysis of RNA samples prepared from the BAT of cold-exposed rats and of rats kept at room temperature. Previously reported elevations of transcript levels of uncoupling protein (UCP1), type II iodothyronine deiodinase (DIO2), and type III adenylate cyclase (AC3) in the BAT of cold-exposed rats over those in that of rats maintained at room temperature were confirmed. In addition to these changes, remarkable elevations of the transcript levels of several genes that seemed to be associated with the processes of cell-cycle regulation and DNA replication were detected in the BAT of cold-exposed rats, possibly reflecting the significant proliferation of brown adipocytes in response to cold exposure. Up-regulation of the gene encoding sarcomeric mitochondrial type creatine kinase in the BAT of cold-exposed rats was also detected by microarray analysis, but subsequent Northern analysis revealed that the expression of not only the sarcomeric mitochondrial type enzyme, but also that of 2 other subtypes, i.e., cytoplasmic brain type and cytoplasmic muscle type, was elevated in the BAT of cold-exposed rats. Microarray analysis also revealed a significant expression of myoglobin in BAT and its elevation in the BAT of cold-exposed rats, and this result was supported by calibrated Northern analysis. On the contrary, several genes such as regulator of G-protein signaling 2 and IMP dehydrogenase 1 were down-regulated in the BAT of cold-exposed rats. The physiological meaning of these changes accompanying cold exposure was discussed.
    Preview · Article · Feb 2008 · Biochimica et Biophysica Acta
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