Uncoupling protein and its mRNA in brown adipose tissue of newborn rabbits

1989 ◽  
Vol 67 (1) ◽  
pp. 54-58 ◽  
Author(s):  
D. K. Rozon ◽  
W. H. Harris ◽  
A. M. Verrinder Gibbins
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Messenger Rna ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Brown Fat ◽  
Guanosine Diphosphate ◽  
Mitochondrial Inner Membrane ◽  
Age Related ◽  
Brown Adipose

Guanosine diphosphate binding to the uncoupling protein of isolated mitochondria of brown adipose tissue in newborn rabbits was measured as an index of thermogenic activity. The binding was 0.281 ± 0.022 nmol GDP/mg mitochondrial protein at 1 day of age, 0.214 ± 0.017 at 3 days, 0.428 ± 0.038 at 5 days, and 0.208 ± 0.016 at 7 days. The increase in binding between 3 and 7 days of age suggests that the brown fat has an increased thermogenic capacity at that age. In addition, the potential for synthesis of the uncoupling protein was investigated in 1- to 5-day-old newborn rabbits by probing the total cellular ribonucleic acid for the messenger that codes for uncoupling protein. The amount of uncoupling protein messenger was highest at 1 day of age and declined at least until 5 days of age. Because the amount of uncoupling protein messenger decreased as the GDP binding increased, the results suggest that either the initially translated uncoupling protein was unmasked at about 5 days of age or there was a delay in the incorporation of uncoupling protein into the mitochondrial inner membrane, or both.Key words: brown fat, neonatal rabbit, thermogenin, messenger RNA, age-related changes.

scholarly journals Uncoupling protein 1 binds one nucleotide per monomer and is stabilized by tightly bound cardiolipin

2015 ◽  
Vol 112 (22) ◽  
pp. 6973-6978 ◽  
Author(s):  
Yang Lee ◽  
Chrissie Willers ◽  
Edmund R. S. Kunji ◽  
Paul G. Crichton
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Size Exclusion ◽  
Uncoupling Protein 1 ◽  
Mitochondrial Carriers ◽  
Mitochondrial Inner Membrane ◽  
Brown Adipose ◽  
Integral Role ◽  
Covalent Chromatography

Uncoupling protein 1 (UCP1) catalyzes fatty acid-activated, purine nucleotide-sensitive proton leak across the mitochondrial inner membrane of brown adipose tissue to produce heat, and could help combat obesity and metabolic disease in humans. Studies over the last 30 years conclude that the protein is a dimer, binding one nucleotide molecule per two proteins, and unlike the related mitochondrial ADP/ATP carrier, does not bind cardiolipin. Here, we have developed novel methods to purify milligram amounts of UCP1 from native sources by using covalent chromatography that, unlike past methods, allows the protein to be prepared in defined conditions, free of excess detergent and lipid. Assessment of purified preparations by TLC reveal that UCP1 retains tightly bound cardiolipin, with a lipid phosphorus content equating to three molecules per protein, like the ADP/ATP carrier. Cardiolipin stabilizes UCP1, as demonstrated by reconstitution experiments and thermostability assays, indicating that the lipid has an integral role in the functioning of the protein, similar to other mitochondrial carriers. Furthermore, we find that UCP1 is not dimeric but monomeric, as indicated by size exclusion analysis, and has a ligand titration profile in isothermal calorimetric measurements that clearly shows that one nucleotide binds per monomer. These findings reveal the fundamental composition of UCP1, which is essential for understanding the mechanism of the protein. Our assessment of the properties of UCP1 indicate that it is not unique among mitochondrial carriers and so is likely to use a common exchange mechanism in its primary function in brown adipose tissue mitochondria.

scholarly journals CCAAT/enhancer-binding proteins α and β in brown adipose tissue: evidence for a tissue-specific pattern of expression during development

1994 ◽  
Vol 302 (3) ◽  
pp. 695-700 ◽  
Author(s):  
C Manchado ◽  
P Yubero ◽  
O Viñas ◽  
R Iglesias ◽  
F Villarroya ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Brown Fat ◽  
Brown Adipocyte ◽  
Fetal Life ◽  
Inhibitory Protein ◽  
Adult Rats ◽  
Stage Of Development ◽  
Brown Adipose

CCAAT/enhancer-binding protein (C/EBP) alpha mRNA and its protein products C/EBP alpha and 30 kDa C/EBP alpha are expressed in rat brown-adipose tissue. Results also demonstrate the expression of C/EBP beta mRNA and its protein products C/EBP beta and liver inhibitory protein (LIP) in the tissue. The abundance of C/EBP alpha and C/EBP beta proteins in adult brown fat is similar to that found in adult liver. However, the expression of C/EBP alpha and C/EBP beta is specifically regulated in brown fat during development. C/EBP alpha, 30 kDa C/EBP alpha, C/EBP beta and LIP content is several-fold higher in fetal brown fat than in the adult tissue, or liver at any stage of development. Peak values are attained in late fetal life, in concurrence with the onset of transcription of the uncoupling protein (UCP) gene, the molecular marker of terminal brown-adipocyte differentiation. When adult rats are exposed to a cold environment, which is a physiological stimulus of brown-adipose tissue hyperplasia and UCP gene expression, a specific rise in C/EBP beta expression with respect to C/EBP alpha, 30 kDa C/EBP alpha and LIP is observed. Present data suggest that the C/EBP family of transcription factors has an important role in the development and terminal differentiation of brown-adipose tissue.

scholarly journals Thermogenic and lipogenic activities in brown adipose tissue of I-strain mice

1985 ◽  
Vol 231 (3) ◽  
pp. 761-764 ◽  
Author(s):  
R Bazin ◽  
D Ricquier ◽  
F Dupuy ◽  
J Hoover-Plow ◽  
M Lavau
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Protein Content ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Fatty Acid Synthetase ◽  
Food Utilization ◽  
Lower Efficiency ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

The thermogenic capacity of brown adipose tissue has been investigated in I-strain mice to determine whether this tissue could play a role in the lower efficiency of food utilization reported in this strain of mice. (1) As compared with C57BL mice (a control strain), interscapular-brown-adipose-tissue weight and lipid percentage were decreased by 40% and 13% respectively in I-strain mice. (2) Mitochondrial protein content and cytochrome c oxidase activity were similar in the two strains, but the number of mitochondrial GDP-binding sites and uncoupling-protein content were increased by 2-fold in I-strain mice. (3) Fatty acid synthetase and citrate-cleavage enzyme (units/mg of protein) were 3-fold higher in the brown adipose tissue of I-strain mice. These results indicate that I-strain mice possess a very active brown adipose tissue. This enhanced capacity of energy dissipation in brown adipose tissue could contribute to the decreased capacity of I-strain mice to store adipose tissue.

Identification of two mitochondrial GDP-binding sites in rat brown adipose tissue

1983 ◽  
Vol 3 (7) ◽  
pp. 589-598 ◽  
Author(s):  
K. R. Bryant ◽  
N. J. Rothwell ◽  
M. J. Stock ◽  
D. Stribling
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Binding Sites ◽  
Dissociation Constants ◽  
Mitochondrial Protein ◽  
Scatchard Analysis ◽  
Nucleotide Binding Sites ◽  
Guanosine Diphosphate ◽  
Brown Adipose ◽  
Number Of Binding Sites

Scatchard analysis of specific guanosine-diphosphate-([3H]GDP-) binding to rat brown-adipose-tissue mitochondria revealed two distinct binding sites with apparent dissociation constants (Kd) of approximately 0.05 and 2.0 μM. Binding to both sites was insensitive to atractyloside. Reducing the pH of the binding medium from 7.1 to 6.6 caused marked reductions in the Kd of both sites, but at pH 7.6, the dissociation constants were increased about 3-fold. Acute treatment of rats with noradrenaline, 1 h before sacrifice, increased the maximum number of binding sites (Bmax, pmol/rng mitochondrial protein) of both sites and also increased the dissociation constants. The Bmax of the lower-affinity site was elevated in rats exposed to 5°C or fed a palatable cafeteria diet for 10 d, compared to control animals, with the greater changes occurring in the cold-adapted group. The high-affinity site was unaltered by cold adaptation or cafeteria feeding. These results indicate the presence of two distinct nucleotide-binding sites in brown-fat mitochondria, both of which may be involved in thermogenesis.

Brown adipose tissue activity in hypocaloric-diet fed lactating rats

1986 ◽  
Vol 6 (7) ◽  
pp. 669-675 ◽  
Author(s):  
Francesc Villarroya ◽  
Antonio Felipe ◽  
Teresa Mampel
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Protein ◽  
Caloric Intake ◽  
Brown Fat ◽  
Hypocaloric Diet ◽  
Lipoprotein Lipase Activity ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Brown Adipose Tissue Activity

Hypocaloric diet feeding reduced the mitochondrial protein content and whole tissue GDP-binding in interscapular brown adipose tissue from both virgin and lactating rats. A reduction in brown fat lipoprotein lipase activity was also detected in underfed virgin and lactating animals. These results indicate that lactation in the rat, even though it produces a reduction in brown fat activity, does not impair the capacity of the tissue to respond to a diminished caloric intake by lowering its activity further.

Regulation of the level of uncoupling protein in brown adipose tissue by insulin

1990 ◽  
Vol 258 (2) ◽  
pp. R418-R424 ◽  
Author(s):  
A. Geloen ◽  
P. Trayhurn
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Protein Content ◽  
White Adipose Tissue ◽  
Oxidase Activity ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Brown Adipose ◽  
Epididymal White Adipose Tissue

The role of insulin in the regulation of the thermogenic activity and capacity (uncoupling protein content) of brown adipose tissue (BAT) has been investigated using mice made diabetic with streptozotocin and then subsequently infused with different doses of insulin. After 12 days of diabetes, the animals received either 0, 8, 16, or 32 units of insulin.kg body wt-1.day-1 delivered by osmotic minipumps implanted subcutaneously for 12 days. After 12 days of diabetes, body weight, interscapular BAT, and epididymal white adipose tissue weights were each reduced. In BAT, significant decreases (P less than 0.05) in the mitochondrial protein content (63%), cytochrome oxidase activity (79%), mitochondrial GDP binding (51%), and the specific mitochondrial concentration and total tissue content of uncoupling protein (71 and 89%, respectively) were obtained, indicating that the thermogenic activity and capacity of the tissue were reduced in diabetes. The infusion of insulin at a dose of 8 units.kg-1.day-1 normalized mitochondrial GDP binding and doubled the concentration of uncoupling protein. Body weight, epididymal white adipose tissue weight, and the mitochondrial protein content of BAT were restored with 16 units of insulin.kg-1.day-1. Higher doses of insulin did not further increase the specific mitochondrial concentration of uncoupling protein, but the mitochondrial content (and thereby the total uncoupling protein content) of BAT was increased and blood glucose normalized. There was a significant correlation between the dose of insulin replacement and several of the parameters measured in BAT: mitochondrial protein content (r = 0.68, P less than 0.001), cytochrome oxidase activity (r = 0.54, P less than 0.001), and total uncoupling protein content (r = 0.68, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Brown adipose tissue development in the ovine foetus during the final month of gestation

1992 ◽  
Vol 15 ◽  
pp. 174-175
Author(s):  
L. Clarke ◽  
S. van de Waal ◽  
M. A. Lomax ◽  
M. E. Symonds
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Brown Adipose ◽  
Adipose Tissue Development ◽  
Lamb Growth ◽  
Shivering Thermogenesis ◽  
Thermogenic Capacity

In the ovine foetus brown adipose tissue (BAT) is mainly found in the perirenal region and grows rapidly relative to body weight between 70 to 120 days of gestation (Alexander, 1978). After this stage only a small amount of BAT growth occurs in comparison with that of the whole foetus, and in the case of undernutrition may decline (Alexander, 1978). Maternal cold stress, induced by winter shearing twin-bearing pregnant ewes 8 weeks before parturition improves lamb birth weight and lamb growth rate independently of effects on maternal food intake (Symonds, Bryant and Lomax, 1986 and 1990). At the same time this can stimulate the in vivo capacity for non-shivering thermogenesis in newborn lambs (Stott and Slee, 1985). The following study extends these findings by investigating the extent to which changing the maternal metabolic environment influences BAT development over the final month of gestation.Thirty-two Bluefaced Leicester × Swaledale ewes were housed individually at ambient temperature (−6 to 19°C) 6 weeks prior to lambing and 2 weeks later 15 ewes were shorn. Ewes were offered daily a diet comprising 200 g barley concentrate and 1 kg chopped hay. Between 116 and 145 days of gestation and within 2 h of birth ewes were humanely slaughtered with an overdose of barbiturate and foetal or neonatal perirenal BAT sampled, born from shorn or unshorn ewes. The thermogenic capacity of BAT was assessed by guanosine-5′-diphosphate (GDP) binding to uncoupling protein in mitochondrial preparations (Cooper, Dascombe, Rothwell and Vale, 1989) and the amount of mitochondrial protein measured from cytochrome Coxidase activity.

scholarly journals Sequential changes in the expression of mitochondrial protein mRNA during the development of brown adipose tissue in bovine and ovine species. Sudden occurrence of uncoupling protein mRNA during embryogenesis and its disappearance after birth

1989 ◽  
Vol 257 (3) ◽  
pp. 665-671 ◽  
Author(s):  
L Casteilla ◽  
O Champigny ◽  
F Bouillaud ◽  
J Robelin ◽  
D Ricquier
Keyword(s):  
Adipose Tissue ◽  
Cytochrome C ◽  
Brown Adipose Tissue ◽  
Cytochrome C Oxidase ◽  
Uncoupling Protein ◽  
Subcutaneous Tissue ◽  
Mitochondrial Protein ◽  
Sequence Of Events ◽  
Brown Adipose

Samples of adipose tissue were obtained from different sites in bovine and ovine foetuses and newborns. RNA was isolated and analysed using bovine cDNA and ovine genomic probe for uncoupling protein (UCP), cDNA for subunits III and IV of cytochrome c oxidase and cDNA for ADP/ATP carrier. UCP mRNA was characterized for the first time in foetal bovine and ovine adipose tissue. It appeared later than mRNA of cytochrome c oxidase subunit III, and increased dramatically at birth (10-fold). ADP/ATP carrier mRNA was expressed at a lower level but also increased 10-fold at birth. It was demonstrated that UCP mRNA reached its highest level at birth in all bovine adipose tissues studied, except subcutaneous tissue. It disappeared quickly afterwards, being no longer detectable two days after birth. Similar variations were observed in newborn lambs. ADP/ATP carrier mRNA showed the same pattern of expression as UCP mRNA; although it was still lightly expressed two days after birth, it disappeared soon afterwards. Only mRNAs for cytochrome c oxidase subunits III and IV remained at the same level during the first postnatal week. On the basis of these data and of observations reported in the literature a sequence of events for the development of brown adipose cells in vivo is proposed. Soon after birth the perirenal adipose tissue of ruminants, which still contains mitochondria of typical brown adipose tissue morphology and high levels of cytochrome c oxidase mRNA, lacks UCP mRNA. Can it still be considered as brown fat? Ruminant species appear to be attractive models to study both the differentiation of brown adipose tissue and its possible conversion to white fat in large animals.

Guanosine diphosphate binding to brown adipose tissue mitochondria is increased after single meal

1985 ◽  
Vol 249 (6) ◽  
pp. R694-R698 ◽  
Author(s):  
J. R. Lupien ◽  
Z. Glick ◽  
M. Saito ◽  
G. A. Bray
Keyword(s):  
Adipose Tissue ◽  
Atpase Activity ◽  
Brown Adipose Tissue ◽  
Test Meal ◽  
Brown Fat ◽  
Guanosine Diphosphate ◽  
Brown Adipose ◽  
Single Meal ◽  
Time Changes ◽  
Fat Depot

A single meal results in an increased thermic activity of brown adipose tissue (BAT). The purpose of the present studies was threefold: 1) to identify major metabolic origins involved in this thermic response, 2) to determine the effect of meal composition on it, and 3) to determine time changes in postprandial brown fat thermogenesis. Wistar rats were trained to eat during 2 feeding sessions/day. On the days of the experiment, rats received a test meal for 2 h, and respective control rats were simultaneously meal deprived. The animals were killed at one or more time points after meal onset, and their BAT was removed for determination of mitochondrial guanosine diphosphate (GDP) binding to indicate rate of uncoupled respiration (expts 1 and 3) or Na+-K+-ATPase activity representing coupled respiration (expt 2). Meal taking was followed by an 85% increase in GDP binding (P less than 0.001). In contrast, Na+-K+-ATPase activity was not altered by a test meal of a similar composition. The largest meal-induced rise in mitochondrial GDP binding was evident during the early postprandial hours, and it was greatly reduced by 10 h after meal onset. Expressed per total interscapular brown fat depot, a high-carbohydrate meal caused a greater increase in GDP binding than an equicaloric high-fat meal. Our data indicate that the BAT proton conductance pathway is activated by a single meal.

Effect of fetal thyroidectomy on brown adipose tissue and thermoregulation in newborn lambs

1996 ◽  
Vol 8 (6) ◽  
pp. 995 ◽  
Author(s):  
SJ Schermer ◽  
JA Bird ◽  
MA Lomax ◽  
DA Shepherd ◽  
ME Symonds
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Late Gestation ◽  
Guanosine Diphosphate ◽  
Functional Development ◽  
Brown Adipose ◽  
Colonic Temperature ◽  
Shivering Thermogenesis

The effect of fetal thyroidectomy on thermoregulation in newborn lambs was investigated. Seven of 14 lambs born normally at term were thyroidectomized at Day 127 of gestation. Colonic temperature and oxygen consumption were measured during non-rapid eye movement sleep 6-45 h after birth. All lambs were then killed and perirenal brown adipose tissue was sampled for measurement of thermogenic activity (guanosine diphosphate binding), uncoupling protein and lipid contents. Thyroidectomized lambs tended to have a mean colonic temperature 2.35 degrees C lower (P = 0.067) than controls and two became hypothermic (i.e. colonic temperature < 35 degrees C). Thyroidectomized lambs exhibited lower rates of oxygen consumption (P = 0.05) and an increased incidence of shivering thermogenesis. The perirenal adipose tissue of these lambs had a lower thermogenic activity (P < 0.01), less uncoupling protein (P < 0.01) and higher lipid content (P = 0.072) compared with intact controls. It is concluded that fetal thyroidectomy results in a decreased ability of newborn lambs to utilize nonshivering thermogenesis in brown adipose tissue as well as increasing the incidence of hypothermia. These changes are associated with decreased synthesis of uncoupling protein and functional development of brown adipose tissue in the late gestation fetus.

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