scholarly journals Characterization of brown adipose tissue thermogenesis in the naked mole-rat (Heterocephalus glaber), a heterothermic mammal

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuki Oiwa ◽  
Kaori Oka ◽  
Hironobu Yasui ◽  
Kei Higashikawa ◽  
Hidemasa Bono ◽  
...  

Abstract The naked mole-rat (NMR) is a heterothermic mammal that forms eusocial colonies consisting of one reproductive female (queen), several reproductive males, and subordinates. Despite their heterothermy, NMRs possess brown adipose tissue (BAT), which generally induces thermogenesis in cold and some non-cold environments. Previous studies suggest that NMR-BAT induces thermogenesis by cold exposure. However, detailed NMR-BAT characteristics and whether NMR-BAT thermogenesis occurs in non-cold environments are unknown. Here, we show beta-3 adrenergic receptor (ADRB3)-dependent thermogenic potential of NMR-BAT, which contributes to thermogenesis in the isolated queen in non-cold environments (30 °C). NMR-BAT expressed several brown adipocyte marker genes and showed noradrenaline-dependent thermogenic activity in vitro and in vivo. Although our ADRB3 inhibition experiments revealed that NMR-BAT thermogenesis slightly delays the decrease in body temperature in a cold environment (20 °C), it was insufficient to prevent the decrease in the body temperatures. Even at 30 °C, NMRs are known to prevent the decrease of and maintain their body temperature by heat-sharing behaviors within the colony. However, isolated NMRs maintained their body temperature at the same level as when they are in the colony. Interestingly, we found that queens, but not subordinates, induce BAT thermogenesis in this condition. Our research provides novel insights into NMR thermoregulation.

2020 ◽  
Author(s):  
Yuki Oiwa ◽  
Kaori Oka ◽  
Hironobu Yasui ◽  
Kei Higashikawa ◽  
Hidemasa Bono ◽  
...  

AbstractThe naked mole-rat (NMR) is a poikilothermic mammal that forms eusocial colonies consisting of one breeding queen, several breeding kings, and subordinates. Despite their poikilothermic feature, NMRs possess brown adipose tissue (BAT), which in homeothermic mammals induces thermogenesis in cold environments. However, NMR-BAT thermogenic potential is controversial, and its physiological roles are unknown. Here, we show that NMR-BAT has beta-3 adrenergic receptor (ADRB3)-dependent thermogenic potential, which contributes to thermogenesis in the isolated queen in non-cold environments. NMR-BAT expressed several brown adipocyte marker genes and showed noradrenaline-dependent thermogenic activity in vitro and in vivo. Although our ADRB3 inhibition experiments revealed that NMR-BAT thermogenesis slightly delays the decrease in body temperature in a cold environment, it was insufficient to maintain the body temperatures of the NMRs. In a non-cold environment, NMRs are known to increase their body temperature by a heat-sharing behavior. Interestingly, we found that the body temperatures of NMRs isolated from the colony were also significantly higher than the ambient temperature. We also show that queens, but not subordinates, induce BAT thermogenesis in isolated, non-cold conditions. Our research provides novel insights into the role and mechanism of thermoregulation in this unique poikilothermic mammal.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Chao Sun ◽  
Ruixia Zeng ◽  
Ge Cao ◽  
Zhibang Song ◽  
Yibo Zhang ◽  
...  

Recently, vibration training is considered as a novel strategy of weight loss; however, its mechanisms are still unclear. In this study, normal or high-fat diet-induced rats were trained by whole body vibration for 8 weeks. We observed that the body weight and fat metabolism index, blood glucose, triglyceride, cholesterol, and free fatty acid in obesity rats decreased significantly compared with nonvibration group(n=6). Although intrascapular BAT weight did not change significantly, vibration enhanced ATP reduction and increased protein level of the key molecule of brown adipose tissue (BAT), PGC-1α, and UCP1 in BAT. Interestingly, the adipocytes in retroperitoneal white adipose tissue (WAT) became smaller due to vibration exercise and had higher protein level of the key molecule of brown adipose tissue (BAT), PGC-1α, and UCP1 and inflammatory relative proteins, IL-6 and TNFα. Simultaneously, ATP content and PPARγprotein level in WAT became less in rats compared with nonvibration group. The results indicated that vibration training changed lipid metabolism in rats and promoted brown fat-like change in white adipose tissues through triggering BAT associated gene expression, inflammatory reflect, and reducing energy reserve.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adela Urisarri ◽  
Ismael González-García ◽  
Ánxela Estévez-Salguero ◽  
María P. Pata ◽  
Edward Milbank ◽  
...  

AbstractThe classical dogma states that brown adipose tissue (BAT) plays a major role in the regulation of temperature in neonates. However, although BAT has been studied in infants for more than a century, the knowledge about its physiological features at this stage of life is rather limited. This has been mainly due to the lack of appropriate investigation methods, ethically suitable for neonates. Here, we have applied non-invasive infrared thermography (IRT) to investigate neonatal BAT activity. Our data show that BAT temperature correlates with body temperature and that mild cold stimulus promotes BAT activation in newborns. Notably, a single short-term cold stimulus during the first day of life improves the body temperature adaption to a subsequent cold event. Finally, we identify that bone morphogenic protein 8B (BMP8B) is associated with the BAT thermogenic response in neonates. Overall, our data uncover key features of the setup of BAT thermogenesis in newborns.


2021 ◽  
Vol 12 ◽  
Author(s):  
Gina Wade ◽  
Ayren McGahee ◽  
James M. Ntambi ◽  
Judith Simcox

Non-shivering thermogenesis is an energy demanding process that primarily occurs in brown and beige adipose tissue. Beyond regulating body temperature, these thermogenic adipocytes regulate systemic glucose and lipid homeostasis. Historically, research on thermogenic adipocytes has focused on glycolytic metabolism due to the discovery of active brown adipose tissue in adult humans through glucose uptake imaging. The importance of lipids in non-shivering thermogenesis has more recently been appreciated. Uptake of circulating lipids into thermogenic adipocytes is necessary for body temperature regulation and whole-body lipid homeostasis. A wide array of circulating lipids contribute to thermogenic potential including free fatty acids, triglycerides, and acylcarnitines. This review will summarize the mechanisms and regulation of lipid uptake into brown adipose tissue including protein-mediated uptake, lipoprotein lipase activity, endocytosis, vesicle packaging, and lipid chaperones. We will also address existing gaps in knowledge for cold induced lipid uptake into thermogenic adipose tissue.


2021 ◽  
Author(s):  
Mingsheng Ye ◽  
Liping Luo ◽  
Qi Guo ◽  
Guanghua Lei ◽  
Chao Zeng ◽  
...  

Brown adipose tissue (BAT) is emerging as a target to beat obesity through the dissipation of chemical energy to heat. However, the molecular mechanisms of brown adipocyte thermogenesis remain to be further elucidated. Here, we show that KCTD10, a member of the polymerase delta-interacting protein 1 (PDIP1) family, was reduced in BAT by cold stress and a β3 adrenoceptor agonist. Moreover, KCTD10 level increased in the BAT of obese mice, and KCTD10 overexpression attenuates uncoupling protein 1 (UCP1) expression in primary brown adipocytes. BAT-specific KCTD10 knockdown mice had increased thermogenesis and cold tolerance protecting from high fat diet (HFD)-induced obesity. Conversely, overexpression of KCTD10 in BAT caused reduced thermogenesis, cold intolerance, and obesity. Mechanistically, inhibiting Notch signaling restored the KCTD10 overexpression suppressed thermogenesis. Our study presents that KCTD10 serves as an upstream regulator of notch signaling pathway to regulate BAT thermogenesis and whole-body metabolic function.


2019 ◽  
Vol 317 (5) ◽  
pp. E742-E750 ◽  
Author(s):  
Tania Quesada-López ◽  
Aleix Gavaldà-Navarro ◽  
Samantha Morón-Ros ◽  
Laura Campderrós ◽  
Roser Iglesias ◽  
...  

Adaptive induction of thermogenesis in brown adipose tissue (BAT) is essential for the survival of mammals after birth. We show here that G protein-coupled receptor protein 120 (GPR120) expression is dramatically induced after birth in mouse BAT. GPR120 expression in neonatal BAT is the highest among GPR120-expressing tissues in the mouse at any developmental stage tested. The induction of GPR120 in neonatal BAT is caused by postnatal thermal stress rather than by the initiation of suckling. GPR120-null neonates were found to be relatively intolerant to cold: close to one-third did not survive at 21°C, but all such pups survived at 25°C. Heat production in BAT was significantly impaired in GPR120-null pups. Deficiency in GPR120 did not modify brown adipocyte morphology or the anatomical architecture of BAT, as assessed by electron microscopy, but instead impaired the expression of uncoupling protein-1 and the fatty acid oxidation capacity of neonatal BAT. Moreover, GPR120 deficiency impaired fibroblast growth factor 21 (FGF21) gene expression in BAT and reduced plasma FGF21 levels. These results indicate that GPR120 is essential for neonatal adaptive thermogenesis.


1983 ◽  
Vol 245 (6) ◽  
pp. E555-E559 ◽  
Author(s):  
D. Szillat ◽  
L. J. Bukowiecki

Adenosine competitively inhibited the stimulatory effects of (-)-isoproterenol on lipolysis and respiration in hamster brown adipocytes. The low value of the apparent ki for respiratory inhibition by adenosine (7 nM) indicated that the nucleoside may control brown adipocyte function under physiological concentrations. Significantly, the dose-response curves for isoproterenol stimulation of lipolysis and respiration were both shifted by adenosine to higher agonist concentrations by the same order of magnitude, providing additional evidence for a tight coupling between lipolysis and respiration. The inhibitory effects of adenosine were rapidly reversed by a) adenosine deaminase, b) agents known to increase intracellular cyclic AMP levels (isoproterenol, isobutylmethylxanthine, dibutyryl cyclic AMP), and c) direct stimulation of respiration with palmitic acid. These results, combined with the fact that adenosine failed to affect respiration evoked either by dibutyryl cyclic AMP or by palmitic acid, strongly indicate that adenosine regulates brown adipose tissue respiration at an early metabolic step of the stimulus-thermogenesis sequence, most probably at the level of the adenylate cyclase complex.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Peng Zhou ◽  
Maricela Robles-Murguia ◽  
Deepa Mathew ◽  
Giles E. Duffield

Inhibitor of DNA binding 2 (ID2) is a helix-loop-helix transcriptional repressor rhythmically expressed in many adult tissues. Our previous studies have demonstrated thatId2null mice have sex-specific elevated glucose uptake in brown adipose tissue (BAT). Here we further explored the role ofId2in the regulation of core body temperature over the circadian cycle and the impact ofId2deficiency on genes involved in insulin signaling and adipogenesis in BAT. We discovered a reduced core body temperature inId2−/− mice. Moreover, inId2−/− BAT, 30 genes includingIrs1,PPARs, andPGC-1s were identified as differentially expressed in a sex-specific pattern. These data provide valuable insights into the impact ofId2deficiency on energy homeostasis of mice in a sex-specific manner.


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