Nature's fat-burning machine: brown adipose tissue in a hibernating mammal

Ballinger, Mallory A.; Andrews, Matthew T.

doi:10.1242/jeb.162586

Cited by 48 publications

(35 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recruitment and activation of BAT is crucial for its full thermogenic capacity required to cope with low temperatures . Alterations in the photoperiod act as a fundamental predictor to that adaptive process, and they are conveyed to BAT by the seasonal variation in plasma melatonin daily profile duration, so that pinealectomized hibernating animals are less able to respond to cold‐induced thermogenesis …”

Section: Introductionmentioning

confidence: 99%

Melatonin multiple effects on brown adipose tissue molecular machinery

Souza

Gallo

Camargo

et al. 2019

Journal of Pineal Research

View full text Add to dashboard Cite

Brown adipose tissue (BAT) influences energy balance through nonshivering thermogenesis, and its metabolism daily and seasonal variations are regulated by melatonin through partially known mechanisms. We evaluated the role of melatonin in BAT molecular machinery of male Control, pinealectomized (PINX), and melatonin‐treated pinealectomized (PINX/Mel) adult rats. BAT was collected either every 3 hours over 24 hours or after cold or high‐fat diet (HFD) acute exposure. HFD PINX animals presented decreased Dio2 expression, while HFD PINX/Mel animals showed increased Dio2, Ucp1, and Cidea expression. Cold‐exposed PINX rats showed decreased Dio2 and Lhs expression, and melatonin treatment augmented Adrβ3, Dio2, Ucp1, and Cidea expression. Daily profiles analyses showed altered Dio2, Lhs, Ucp1, Pgc1α, and Cidea gene and UCP1 protein expression in PINX animals, leading to altered rhythmicity under sub‐thermoneutral conditions, which was partially restored by melatonin treatment. The same was observed for mitochondrial complexes I, II, and IV protein expression and enzyme activity. Melatonin absence seems to impair BAT responses to metabolic challenges, and melatonin replacement reverses this effect, with additional increase in the expression of crucial genes, suggesting that melatonin plays an important role in several key points of the thermogenic activation pathway, influencing both the rhythmic profile of the tissue and its ability to respond to metabolic challenges, which is crucial for the organism homeostasis.

show abstract

Section: Introductionmentioning

confidence: 99%

Melatonin multiple effects on brown adipose tissue molecular machinery

Souza

Gallo

Camargo

et al. 2019

Journal of Pineal Research

View full text Add to dashboard Cite

show abstract

“…AGS are robust hibernators where the hibernation phenotype is strongly regulated by season. In hibernators, BAT is the main site of NST (Ballinger and Andrews, 2018). BAT thermogenesis is regulated synergistically by the sympathetic nervous system (SNS) and thyroid hormones (TH; Ortiga-Carvalho et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

The Raphe Pallidus and the Hypothalamic-Pituitary-Thyroid Axis Gate Seasonal Changes in Thermoregulation in the Hibernating Arctic Ground Squirrel (Urocitellus parryii)

et al. 2018

View full text Add to dashboard Cite

Thermoregulation is necessary to maintain energy homeostasis. The novel discovery of brown adipose tissue (BAT) in humans has increased research interests in better understanding BAT thermogenesis to restore energy balance in metabolic disorders. The hibernating Arctic ground squirrel (AGS) offers a novel approach to investigate BAT thermogenesis. AGS seasonally increase their BAT mass to increase the ability to generate heat during interbout arousals. The mechanisms promoting the seasonal changes in BAT thermogenesis are not well understood. BAT thermogenesis is regulated by the raphe pallidus (rPA) and by thyroid hormones produced by the hypothalamic–pituitary–thyroid (HPT) axis. Here, we investigate if the HPT axis and the rPA undergo seasonal changes to modulate BAT thermogenesis in hibernation. We used histological analysis and tandem mass spectrometry to assess activation of the HPT axis and immunohistochemistry to measure neuronal activation. We found an increase in HPT axis activation in fall and in response to pharmacologically induced torpor when adenosine A1 receptor agonist was administered in winter. By contrast, the rPA neuronal activation was lower in winter in response to pharmacologically induced torpor. Activation of the rPA was also lower in winter compared to the other seasons. Our results suggest that thermogenic capacity develops during fall as the HPT axis is activated to reach maximum capacity in winter seen by increased free thyroid hormones in response to cooling. However, thermogenesis is inhibited during torpor as sympathetic premotor neuronal activation is lower in winter, until arousal when inhibition of thermogenesis is relieved. These findings describe seasonal modulation of thermoregulation that conserves energy through attenuated sympathetic drive, but retains heat generating capacity through activation of the HPT axis.

show abstract

“…BAT is the core site of non-shivering thermogenesis (Ballinger and Andrews, 2018) in hibernators. Hibernation as a seasonal event is preceded by a reduction transition phase that body weight augmented (MacCannell et al, 2017) and body temperature diminishes (Sheriff et al, 2012).…”

Section: Medullary Raphe Neurons Facilitate Bat Activationmentioning

confidence: 99%

Contribution of nucleus raphe magnus to thermoregulation

2020

View full text Add to dashboard Cite

Thermoregulation is the maintenance of the core body temperature. The regulation of body temperature is one of the most important functions of the nervous system. Nucleus raphe magnus, as a central circuit coordinates the homeostatic response and maintains body temperature during environmental temperature challenges and adjusts body temperature during the inflammatory response and behavioral states and in response to decreasing energy homeostasis. Our aim in this review is the understanding of thermoregulation by raphe magnus in mammals. This review summarizes the basic concepts of thermoregulation and subsequently assesses the physiological responses to cold stress, including skin blood flow control, sweating, sympathetic-derived cutaneous vasoconstriction and peripheral thermoregulatory control in brown adipose tissue.

show abstract

Nature's fat-burning machine: brown adipose tissue in a hibernating mammal

Cited by 48 publications

References 103 publications

Melatonin multiple effects on brown adipose tissue molecular machinery

Melatonin multiple effects on brown adipose tissue molecular machinery

The Raphe Pallidus and the Hypothalamic-Pituitary-Thyroid Axis Gate Seasonal Changes in Thermoregulation in the Hibernating Arctic Ground Squirrel (Urocitellus parryii)

Contribution of nucleus raphe magnus to thermoregulation

Contact Info

Product

Resources

About