scholarly journals Postnatal recruitment of brown adipose tissue is induced by the cold stress experienced by the pups. An analysis of mRNA levels for thermogenin and lipoprotein lipase

1989 ◽  
Vol 259 (2) ◽  
pp. 341-346 ◽  
Author(s):  
M J Obregón ◽  
A Jacobsson ◽  
T Kirchgessner ◽  
M C Schotz ◽  
B Cannon ◽  
...  

In order to investigate the postnatal recruitment process, gene expression in the brown adipose tissue of rat pups was followed during the first 20 h of life. In normal pups, the level of mRNA coding for the uncoupling protein thermogenin increased markedly but gradually within the first 24 h. Lipoprotein lipase and actin mRNA levels were relatively low and remained constant. In pups exposed to thermoneutral temperature (35 degrees C) for the first 12 h after birth, no increase in thermogenin mRNA or lipoprotein lipase mRNA was observed, whereas in pups exposed to 28 degrees C a clear increase in both thermogenin and lipoprotein lipase mRNA levels was found. Actin mRNA levels were not affected by the environmental temperature under these circumstances. It was concluded that the postnatal recruitment in brown adipose tissue is a consequence of the cold stress experienced by the newborn pups. Thus, postnatal recruitment is not ontogenically predetermined.

1996 ◽  
Vol 314 (1) ◽  
pp. 261-267 ◽  
Author(s):  
María-Jesus OBREGÓN ◽  
Barbara CANNON ◽  
Jan NEDERGAARD

The levels of mRNA coding for the uncoupling protein (UCP) and for lipoprotein lipase (LPL) were monitored in the brown adipose tissue of newborn rat pups. At 5 h after birth, the mRNA levels of UCP and LPL were high in pups exposed singly to 28 °C and low in pups kept singly at thermoneutrality (36 °C); in pups staying with the dam, the UCP mRNA levels were intermediate. However, the LPL mRNA levels were lower in pups staying with the dam than in pups at 36 °C, implying that factors additional to environmental temperature influenced LPL gene expression. Injection of noradrenaline into pups at thermoneutrality (36 °C) led to increases in UCP and LPL gene expression, but noradrenaline injections had no further effect in cold-exposed pups. The adrenergic effects were mediated via β-adrenergic receptors. The cold-induced increases in both UCP and LPL gene expression were abolished by the β-adrenergic antagonist propranolol. Thus differences in adrenergic responsiveness could not explain the differential expression of the UCP and LPL genes observed in pups staying with the dam. The presence of a physiological suppressor was examined by feeding single pups at 28 °C with different foods: nothing, water, Intralipid, cow's milk, rat milk and rat colostrum. None of these agents led to suppression of UCP gene expression, but colostrum led to a selective suppression of LPL gene expression. It was concluded that the genes for UCP and LPL were responsive to adrenergic stimuli immediately after birth, and it is suggested that a component of rat colostrum can selectively suppress LPL gene expression.


2020 ◽  
Vol 245 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Chunchun Wei ◽  
Xianhua Ma ◽  
Kai Su ◽  
Shasha Qi ◽  
Yuangang Zhu ◽  
...  

Brown adipose tissue (BAT) plays a critical role in energy expenditure by uncoupling protein 1 (UCP1)-mediated thermogenesis. Carbohydrate response element-binding protein (ChREBP) is one of the key transcription factors regulating de novo lipogenesis (DNL). As a constitutively active form, ChREBP-β is expressed at extremely low levels. Up to date, its functional relevance in BAT remains unclear. In this study, we show that ChREBP-β inhibits BAT thermogenesis. BAT ChREBP-β mRNA levels were elevated upon cold exposure, which prompted us to generate a mouse model overexpressing ChREBP-β specifically in BAT using the Cre/LoxP approach. ChREBP-β overexpression led to a whitening phenotype of BAT at room temperature, as evidenced by increased lipid droplet size and decreased mitochondrion content. Moreover, BAT thermogenesis was inhibited upon acute cold exposure, and its metabolic remodeling induced by long-term cold adaptation was significantly impaired by ChREBP-β overexpression. Mechanistically, ChREBP-β overexpression downregulated expression of genes involved in mitochondrial biogenesis, autophagy, and respiration. Furthermore, thermogenic gene expression (e.g. Dio2, UCP1) was markedly inhibited in BAT by the overexpressed ChREBP-β. Put together, our work points to ChREBP-β as a negative regulator of thermogenesis in brown adipocytes.


1989 ◽  
Vol 67 (2-3) ◽  
pp. 147-151 ◽  
Author(s):  
Karl B. Freeman ◽  
Michael Heffernan ◽  
Zenobia Dhalla ◽  
Hasmukh V. Patel

The effect of temperature on the amount of uncoupling protein mRNA in rat brown adipose tissue was examined after 1 and 14 days of exposure to cold. The relative amounts after 1 day, compared with rats kept at a thermoneutral temperature of 28 °C, were 3.2 at 19 °C, 3.3 at 11 °C, and 2.1 at 3 °C. This suggests that in warm-acclimated rats, a maximal response to a cold stimulus in brown adipose tissue is reached by 19 °C. In contrast to these results, the relative amounts of uncoupling protein mRNA after 14 days of cold exposure, compared with rats left at 28 °C, were 1.2 at 19 °C, 1.9 at 11 °C, and 2.1 at 3 °C. Since it is known that the amount of uncoupling protein in cold-acclimated rats increases continuously with decrease in temperature, the amount of protein reflects the mRNA levels during later times but not the initial time of exposure to cold.Key words: brown adipose tissue, uncoupling protein mRNA.


1997 ◽  
Vol 321 (3) ◽  
pp. 759-767 ◽  
Author(s):  
Pertti KUUSELA ◽  
Stefan REHNMARK ◽  
Anders JACOBSSON ◽  
Barbara CANNON ◽  
Jan NEDERGAARD

In order to investigate whether the positive effect of adrenergic stimulation on lipoprotein lipase (LPL) gene expression in brown adipose tissue is a direct effect on the brown adipocytes themselves, the expression of the LPL gene was investigated by measuring LPL mRNA levels in brown adipocytes, isolated as precursors from the brown adipose tissue of rats and grown in culture in a fully defined medium before experimentation. Addition of noradrenaline led to an enhancement of LPL gene expression; the mRNA levels increased as a linear function of time for at least 5 h and were finally approx. 3 times higher than in control cells, an increase commensurate with that seen in vivoin both LPL mRNA levels and LPL activity during physiological stimulation. The increase was dependent on transcription. The effect of noradrenaline showed simple MichaelisŐMenten kinetics with an EC50 of approx. 11 nM. β3-Agonists (BRL-37344 and CGP-12177) could mimic the effect of noradrenaline; the β1-agonist dobutamine and the β2-agonist salbutamol could not; the α1-agonist cirazoline had only a weak effect. The effect of noradrenaline was fully inhibited by the β-antagonist propranolol and was halved by the α1-antagonist prazosin; the α2-antagonist yohimbine was without effect. An increase in LPL mRNA level similar to (but not significantly exceeding) that caused by noradrenaline could also be induced by the cAMP-elevating agents forskolin and cholera toxin, and 8-Br-cAMP also increased LPL mRNA levels. The increase in LPL gene expression was not mediated via an increase in the level of an intermediary proteinaceous factor. It is concluded that the physiologically induced increase in LPL gene expression is a direct effect of noradrenaline on the brown adipocytes themselves, mediated via a dominant β3-adrenergic pathway and an auxillary α1-adrenergic pathway which converge at a regulatory point in transcriptional control.


2002 ◽  
Vol 174 (3) ◽  
pp. 427-433 ◽  
Author(s):  
H Budge ◽  
A Mostyn ◽  
V Wilson ◽  
A Khong ◽  
AM Walker ◽  
...  

The present study determines whether maternal administration of prolactin (PRL) to dams promotes the abundance of the brown adipose tissue-specific uncoupling protein-1 (UCP1) in fetal and neonatal rat pups. Recombinant PRL (24 micro g/kg per day), or an equivalent volume of saline, were infused into dams (n=19 per group) throughout pregnancy from 12 h after mating. Interscapular brown adipose tissue was sampled either from fetuses at 19.5 days of gestation (term=21.5 days) or from neonatal rat pups at approximately 18 h after birth. The abundance of UCP1 was determined by immunoblotting on adipose tissue samples from individual pups and pooled from groups of pups. This analysis was complemented by immunocytochemistry on representative adipose tissue samples. Maternal PRL infusion resulted in a greater abundance of UCP1 in fetal rats at 19.5 days of gestation (control: 97.2+/-8.4% reference; PRL: 525.6+/-74.4% reference; P<0.001) and in neonates 18 h after birth. In contrast, the abundance of the outer mitochondrial membrane protein voltage-dependent anion channel was unaffected by PRL. Neonatal adipose tissue sampled from pups born to PRL-infused dams possessed fewer lipid droplets, but more UCP1, as determined by immunocytochemistry. Fetal, but not maternal, plasma leptin concentrations were also increased by maternal PRL administration. In conclusion, as rats are altricial, and the potential thermogenic activity of brown adipose tissue develops over the first few days of postnatal life, these changes prior to, and at the time of, birth implicate PRL in fetal and neonatal adipose tissue maturation.


2021 ◽  
Vol 22 (6) ◽  
pp. 2827
Author(s):  
Vicente Barrios ◽  
Laura M. Frago ◽  
Sandra Canelles ◽  
Santiago Guerra-Cantera ◽  
Eduardo Arilla-Ferreiro ◽  
...  

The growth hormone (GH)/insulin-like growth factor I (IGF-I) axis is involved in metabolic control. Malnutrition reduces IGF-I and modifies the thermogenic capacity of brown adipose tissue (BAT). Leptin has effects on the GH/IGF-I axis and the function of BAT, but its interaction with IGF-I and the mechanisms involved in the regulation of thermogenesis remains unknown. We studied the GH/IGF-I axis and activation of IGF-I-related signaling and metabolism related to BAT thermogenesis in chronic central leptin infused (L), pair-fed (PF), and control rats. Hypothalamic somatostatin mRNA levels were increased in PF and decreased in L, while pituitary GH mRNA was reduced in PF. Serum GH and IGF-I concentrations were decreased only in PF. In BAT, the association between suppressor of cytokine signaling 3 and the IGF-I receptor was reduced, and phosphorylation of the IGF-I receptor increased in the L group. Phosphorylation of Akt and cyclic AMP response element binding protein and glucose transporter 4 mRNA levels were increased in L and mRNA levels of uncoupling protein-1 (UCP-1) and enzymes involved in lipid anabolism reduced in PF. These results suggest that modifications in UCP-1 in BAT and changes in the GH/IGF-I axis induced by negative energy balance are dependent upon leptin levels.


2021 ◽  
Author(s):  
Anna Park ◽  
Kwang-eun Kim ◽  
Isaac Park ◽  
Dae-Soo Kim ◽  
Jaehoon Kim ◽  
...  

Abstract Brown adipose tissue (BAT) has abundant mitochondria with the unique capability of generating heat via uncoupled respiration. Mitochondrial uncoupling protein 1 (Ucp1) is activated in BAT during cold stress and dissipates mitochondrial proton motive force generated by the electron transport chain to generate heat. However, other mitochondrial factors required for brown adipocyte respiration and thermogenesis under cold stress are largely unknown. Here we identify LETM1 domain-containing protein 1 (Letmd1) is a BAT-enriched, cold-induced protein that is required for cold-stimulated respiration and thermogenesis of BAT. Proximity labeling studies reveal that Letmd1 is a mitochondrial matrix protein. Letmd1 knockout mice display aberrant BAT mitochondria and fail to carry out adaptive thermogenesis under cold stress. Letmd1 knockout BAT is deficient in oxidative phosphorylation (OXPHOS) complex proteins and has impaired mitochondrial respiration. Taken together, we identify that the BAT-enriched mitochondrial matrix protein Letmd1 is required for cold-stimulated respiration and thermogenic function of BAT.


1993 ◽  
Vol 265 (1) ◽  
pp. E81-E87 ◽  
Author(s):  
A. Moriscot ◽  
R. Rabelo ◽  
A. C. Bianco

Uncoupling protein (UCP) mRNA levels were studied in the interscapular brown adipose tissue (BAT) of rats undergoing different manipulations of the adrenal function and BAT adrenergic stimulation. Adrenalectomy did not affect UCP mRNA levels for up to 8 days post-surgery. However, adrenalectomized rats underwent a greater increase in UCP mRNA levels (26%) than intact rats after 4 h of cold exposure. Administration of corticosterone (500 micrograms.100 g body wt-1.day-1 sc) to intact or adrenalectomized rats, kept at 28 degrees C, produced a marked decrease of UCP mitochondrial content and cellular mRNA levels in a time-dependent manner (30% by 12 h and 50% by 24 h). Pretreatment of intact rats with corticosterone virtually abolished the UCP mRNA response to cold and norepinephrine (NE). In contrast, when rats had been preexposed to cold for 96 h, the injection of corticosterone did not affect UCP mRNA. These results show that corticosterone is a powerful inhibitor of UCP gene expression in vivo. Corticosterone inhibits both basal gene expression at thermoneutrality and the response to adrenergic stimulation either by cold or exogenous NE, suggesting a direct action on BAT. The data further suggest that corticosterone inhibits the initial accumulation of UCP mRNA mediated by UCP gene transcription, rather than accelerating the degradation of UCP mRNA.


1992 ◽  
Vol 263 (3) ◽  
pp. E500-E506 ◽  
Author(s):  
J. R. Mitchell ◽  
A. Jacobsson ◽  
T. G. Kirchgessner ◽  
M. C. Schotz ◽  
B. Cannon ◽  
...  

The regulation of lipoprotein lipase gene expression in brown adipose tissue was studied. Rats were preacclimated to 21 degrees C. Exposure to cold (4 degrees C) resulted in a rapid increase in the level of lipoprotein lipase mRNA in the tissue. The level peaked (expressed per microgram total RNA) after approximately 8 h and then slowly declined. The increased lipoprotein lipase mRNA level was not due to an increased stability of the mRNA, but, in a transition event from a high to a low expression of the lipoprotein lipase gene, a transcription-dependent process was recruited that accelerated the breakdown of lipoprotein lipase mRNA. Norepinephrine injections increased lipoprotein lipase mRNA levels in the tissue; this effect was mediated via a beta-adrenergic receptor. The effect of cold could be mimicked by norepinephrine injections, and these two effects were not additive, indicating that the cold effect was mediated by norepinephrine. The lipoprotein lipase mRNA level was also increased by insulin injections (into fasted animals); thus an increase in lipoprotein lipase gene expression in brown adipose tissue may be induced via two different stimuli, which, intracellularly, would be mediated via different signaling systems. In all investigated conditions, the changes in lipoprotein lipase mRNA levels observed here were parallelled by alterations in lipoprotein lipase activity reported earlier from this laboratory. It was therefore concluded that, under the conditions studied, lipoprotein lipase activity in brown adipose tissue was primarily regulated at the transcriptional level.


2012 ◽  
Vol 216 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Edward T Wargent ◽  
Jacqueline F O'Dowd ◽  
Mohamed S Zaibi ◽  
Dan Gao ◽  
Chen Bing ◽  
...  

Previous studies by Tisdaleet al. have reported that zinc-α2-glycoprotein (ZAG (AZGP1)) reduces body fat content and improves glucose homeostasis and the plasma lipid profile in Aston (ob/ob) mice. It has been suggested that this might be mediated via agonism of β3- and possibly β2-adrenoceptors. We compared the effects of dosing recombinant human ZAG (100 μg, i.v.) and BRL35135 (0.5 mg/kg, i.p.), which is in rodents a 20-fold selective β3- relative to β2-adrenoceptor agonist, given once daily for 10 days to male C57Bl/6Lepob/Lepobmice. ZAG, but not BRL35135, reduced food intake. BRL35135, but not ZAG, increased energy expenditure acutely and after sub-chronic administration. Only BRL35135 increased plasma concentrations of glycerol and non-esterified fatty acid. Sub-chronic treatment with both ZAG and BRL35135 reduced fasting blood glucose and improved glucose tolerance, but the plasma insulin concentration 30 min after administration of glucose was lowered only by BRL35135. Both ZAG and BRL35135 reduced β1-adrenoceptor mRNA levels in white adipose tissue, but only BRL35135 reduced β2-adrenoceptor mRNA. Both ZAG and BRL35135 reduced β1-adrenoceptor mRNA levels in brown adipose tissue, but neither influenced β2-adrenoceptor mRNA, and only BRL35135 increased β3-adrenoceptor and uncoupling protein-1 (UCP1) mRNA levels in brown adipose tissue. Thus, ZAG and BRL35135 had similar effects on glycaemic control and shared some effects on β-adrenoceptor gene expression in adipose tissue, but ZAG did not display the thermogenic effects of the β-adrenoceptor agonist, nor did it increase β3-adrenoceptor orUCP1gene expression in brown adipose tissue. ZAG does not behave as a typical β3/2-adrenoceptor agonist.


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