Evaluation of Glucose Uptake and Uncoupling Protein 1 Activity in Adipose Tissue of Diabetic Mice upon β-Adrenergic Stimulation

2018 ◽  
Vol 21 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Narumi Kubo ◽  
Mio Kawahara ◽  
Yuko Okamatsu-Ogura ◽  
Yosuke Miyazaki ◽  
Ryuto Otsuka ◽  
...  
1998 ◽  
Vol 333 (2) ◽  
pp. 243-246 ◽  
Author(s):  
Anne-Marie CASSARD-DOULCIER ◽  
Chantal GELLY ◽  
Frédéric BOUILLAUD ◽  
Daniel RICQUIER

The uncoupling protein-1 gene is uniquely expressed in brown adipose tissue (BAT) and is positively regulated by cold exposure of animals and the sympathetic nervous system. To analyse the importance of a previously identified 211-bp enhancer [Cassard-Doulcier, Gelly, Fox, Schrementi, Raimbault, Klaus, Forest, Bouillaud and Ricquier (1993) Mol. Endocrinol. 7, 497–506] in the tissue-specific expression of this gene, transgenic mice were generated using the chloramphenicol acetyltransferase (CAT) gene as a reporter gene. One out of fourteen lines of the control transgenic mice bearing the Herpes simplex thymidine kinase (TK) promoter expressed weakly the CAT reporter gene in several tissues, whereas the other lines did not express CAT. Eight founders bearing the 211-bp enhancer-TK transgene were obtained. In six lines, no expression of CAT was detected. In one line, the expression of CAT was restricted to BAT. In another line, the expression of CAT was found in BAT and, to a lesser extent, in testis. Moreover, in these lines a marked and specific increase in the expression of the reporter gene in BAT was observed either after exposure of mice to the cold or by treating them with a β-adrenoceptor agonist drug. These results demonstrate that the 211-bp enhancer alone is sufficient to both direct and restrict expression to BAT. This enhancer also mediates the transcriptional response of the gene to β-adrenergic stimulation, although it does not contain conserved cAMP response element.


2006 ◽  
Vol 291 (2) ◽  
pp. E350-E357 ◽  
Author(s):  
Valeria Golozoubova ◽  
Barbara Cannon ◽  
Jan Nedergaard

Participation of brown adipose tissue [through the action of the uncoupling protein-1 (UCP1)] in adaptive adrenergic nonshivering thermogenesis is recognized, but the existence of a response to adrenergic stimulation in UCP1-ablated mice implies that a mechanism for an alternative adaptive adrenergic thermogenesis may exist. Here, we have used UCP1-ablated mice to examine the existence of an alternative adaptive adrenergic nonshivering thermogenesis, examined as the oxygen consumption response to systemically injected norepinephrine into anesthetized or conscious mice acclimated to different temperatures. We confirm that UCP1-dependent adrenergic nonshivering thermogenesis is adaptive, but we demonstrate that the adrenergic UCP1-independent thermogenesis is not recruitable by cold acclimation. Thus, at least in the mouse, no other proteins or enzymatic pathways exist that can participate in or with time take over the UCP1 mediation of adaptive adrenergic nonshivering thermogenesis, even in the total absence of UCP1. UCP1 is thus the only protein capable of mediating cold acclimation-recruited adaptive adrenergic nonshivering thermogenesis.


2020 ◽  
Vol 318 (2) ◽  
pp. E198-E215 ◽  
Author(s):  
Stefanie F. Maurer ◽  
Tobias Fromme ◽  
Sabine Mocek ◽  
Anika Zimmermann ◽  
Martin Klingenspor

Uncoupling protein 1 (Ucp1) provides nonshivering thermogenesis (NST) fueled by the dissipation of energy from macronutrients in brown and brite adipocytes. The availability of thermogenic fuels is facilitated by the uptake of extracellular glucose. This conjunction renders thermogenic adipocytes in brown and white adipose tissue (WAT) a potential target against obesity and glucose intolerance. We employed wild-type (WT) and Ucp1-ablated mice to elucidate this relationship. In three experiments of similar setup, Ucp1-ablated mice fed a high-fat diet (HFD) had either reduced or similar body mass gain, food intake, and metabolic efficiency compared with WT mice, challenging the hypothesized role of this protein in the development of diet-induced obesity. Despite the absence of increased body mass, oral glucose tolerance was robustly impaired in Ucp1-ablated mice in response to HFD. Postprandial glucose uptake was attenuated in brown adipose tissue but enhanced in subcutaneous WAT of Ucp1-ablated mice. These differences were explainable by expression of the insulin-responsive member 4 of the facilitated glucose transporter family and fully in line with the capacity for NST in these very tissues. Thus, the postprandial glucose uptake of adipose tissues serves as a surrogate measure for Ucp1-dependent and independent capacity for NST. Collectively, our findings corroborate Ucp1 as a modulator of adipose tissue glucose uptake and systemic glucose homeostasis but challenge its hypothesized causal effect on the development of obesity.


2004 ◽  
Vol 18 (9) ◽  
pp. 2302-2311 ◽  
Author(s):  
Michael A. Nolan ◽  
Maria A. Sikorski ◽  
G. Stanley McKnight

Abstract Mice lacking the RIIβ regulatory subunit of protein kinase A exhibit a 50% reduction in white adipose tissue stores compared with wild-type littermates and are resistant to diet-induced obesity. RIIβ−/− mice also have an increase in resting oxygen consumption along with a 4-fold increase in the brown adipose-specific mitochondrial uncoupling protein 1 (UCP1). In this study, we examined the basis for UCP1 induction and tested the hypothesis that the induced levels of UCP1 in RIIβ null mice are essential for the lean phenotype. The induction of UCP1 occurred at the protein but not the mRNA level and correlated with an increase in mitochondria in brown adipose tissue. Mice lacking both RIIβ and UCP1 (RIIβ−/−/Ucp1−/−) were created, and the key parameters of metabolism and body composition were studied. We discovered that RIIβ−/− mice exhibit nocturnal hyperactivity in addition to the increased oxygen consumption at rest. Disruption of UCP1 in RIIβ−/− mice reduced basal oxygen consumption but did not prevent the nocturnal hyperactivity. The double knockout animals also retained the lean phenotype of the RIIβ null mice, demonstrating that induction of UCP1 and increased resting oxygen consumption is not the cause of leanness in the RIIβ mutant mice.


2019 ◽  
Vol 51 (09) ◽  
pp. 608-617 ◽  
Author(s):  
Lucia Balagova ◽  
Jan Graban ◽  
Agnesa Puhova ◽  
Daniela Jezova

AbstractCatecholamine effects via β3-adrenergic receptors are important for the metabolism of the adipose tissue. Physical exercise is a core component of antiobesity regimens. We have tested the hypothesis that voluntary wheel running results in enhancement of β3-adrenergic receptor gene expression in the white and brown adipose tissues. The secondary hypothesis is that dietary tryptophan depletion modifies metabolic effects of exercise. Male Sprague-Dawley rats were assigned for sedentary and exercise groups with free access to running wheels for 3 weeks. All animals received normal control diet for 7 days. Both groups were fed either by low tryptophan (0.04%) diet or by control diet (0.2%) for next 2 weeks. The β3-adrenergic receptor mRNA levels in response to running increased in the retroperitoneal and epididymal fat pads. The gene expression of uncoupling protein-1 (UCP-1) was increased in the brown, while unchanged in the white fat tissues. Unlike control animals, the rats fed by low tryptophan diet did not exhibit a reduction of the white adipose tissue mass. Tryptophan depletion resulted in enhanced concentrations of plasma aldosterone and corticosterone, but had no influence on exercise-induced adrenal hypertrophy. No changes in β3-adrenergic receptor and cell proliferation measured by 5-bromo-2′-deoxyuridine incorporation in left heart ventricle were observed. The reduced β3-adrenergic receptor but not enhanced uncoupling protein-1 gene expression supports the hypothesis on hypoactive brown adipose tissue during exercise. Reduction in dietary tryptophan had no major influence on the exercise-induced changes in the metabolic parameters measured.


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