Practical application of in vivo MRI‐based brown adipose tissue measurements in infants

Obesity ◽  
2021 ◽  
Vol 29 (10) ◽  
pp. 1676-1683
Author(s):  
Emily W. Flanagan ◽  
Abby D. Altazan ◽  
Owen T. Carmichael ◽  
Houchun H. Hu ◽  
Leanne M. Redman
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Practical Application ◽  
Brown Adipose

Functional characterization of human brown adipose tissue metabolism

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Functional Characterization ◽  
Human Infants ◽  
Positron Emission ◽  
Brown Adipose ◽  
Treatment Of Obesity ◽  
And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

scholarly journals TAF7L modulates brown adipose tissue formation

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Haiying Zhou ◽  
Bo Wan ◽  
Ivan Grubisic ◽  
Tommy Kaplan ◽  
Robert Tjian
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Core Promoter ◽  
Uncoupling Protein ◽  
Dna Looping ◽  
Chromatin Interactions ◽  
Brown Adipose ◽  
Important Regulator

Brown adipose tissue (BAT) plays an essential role in metabolic homeostasis by dissipating energy via thermogenesis through uncoupling protein 1 (UCP1). Previously, we reported that the TATA-binding protein associated factor 7L (TAF7L) is an important regulator of white adipose tissue (WAT) differentiation. In this study, we show that TAF7L also serves as a molecular switch between brown fat and muscle lineages in vivo and in vitro. In adipose tissue, TAF7L-containing TFIID complexes associate with PPARγ to mediate DNA looping between distal enhancers and core promoter elements. Our findings suggest that the presence of the tissue-specific TAF7L subunit in TFIID functions to promote long-range chromatin interactions during BAT lineage specification.

Noradrenaline-induced calorigenesis in warm- or cold-acclimated rats. In vivo estimation of adrenoceptor concentration of noradrenaline effecting half-maximal response

1980 ◽  
Vol 58 (9) ◽  
pp. 1072-1077 ◽  
Author(s):  
Florent Depocas ◽  
Gloria Zaror-Behrens ◽  
Suzanne Lacelle
Keyword(s):  
Adipose Tissue ◽  
Steady State ◽  
Brown Adipose Tissue ◽  
Maximal Response ◽  
Brown Adipose ◽  
Acclimation Group ◽  
Arterial Plasma ◽  
State Concentration ◽  
Na Uptake

Desmethylimipramine (DMI, 1 mg DMI∙HCl kg−1) and normetanephrine (NMN, 1 μg min−1 g−0.74) were used to inhibit, respectively, neuronal and extraneuronal uptakes of noradrenaline (NA) during calorigenesis induced in barbital-sedated warm-acclimated (WA) or cold-acclimated (CA) rats by infusion of NA, a procedure which mimics the effects of NA released within calorigenic tissues in response to cold exposure. The doses of the inhibitors were selected for maximal effectiveness in potentiating calorigenic response and for minimal side effects. For rats of either acclimation group treated with DMI and NMN, with DMI only, or with neither inhibitor the doses of NA required to evoke approximately half-maximal calorigenic responses were, respectively, 0.5, 1.0, and 3.5 ng min−1 g−0.74. The corresponding steady-state concentrations of NA in arterial plasma averaged 14.3, 21.7, and 43.2 nM in the three groups of WA rats and 10.0, 14.8, and 31.9 nM in the three groups of CA rats. Reduction by NA uptake inhibitors of the circulating levels of NA necessary to stimulate calorigenesis, half-maximally, presumably in brown adipose tissue, indicates a reduction in the steepness of the NA concentration gradient between capillary plasma and synaptic clefts in that tissue. The steady-state concentration of NA in blood plasma of rats treated with DMI and NMN and infused with NA at a dose of 0.5 ng min−1 g−0.74 (~1 × 10−8 M) is a good estimate of the NA concentration required at calorigenic adrenoceptors to effect half-maximal activation. Presumably, this concentration is also an estimate of that resulting from NA released at nerve endings during cold-induced activation of nonshivering thermogenesis at half-maximal rates in brown adipose tissue.

scholarly journals In vivo isotope tracing reveals the versatility of glucose as a brown adipose tissue substrate

Cell Reports ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 109459
Author(s):  
Su Myung Jung ◽  
Will G. Doxsey ◽  
Johnny Le ◽  
John A. Haley ◽  
Lorena Mazuecos ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Isotope Tracing ◽  
Brown Adipose

Recombinant Lactococcus lactis NZ3900 expressing bioactive human FGF21 reduced body weight of Db/Db mice through the activity of brown adipose tissue

2020 ◽  
Vol 11 (1) ◽  
pp. 67-78 ◽  
Author(s):  
W.-Y. Cao ◽  
M. Dong ◽  
Z.-Y. Hu ◽  
J. Wu ◽  
Y.-C. Li ◽  
...  
Keyword(s):  
Body Weight ◽  
Antibiotic Resistance ◽  
Adipose Tissue ◽  
Oral Administration ◽  
Brown Adipose Tissue ◽  
Lactococcus Lactis ◽  
Metabolic Diseases ◽  
Brown Adipose ◽  
Human Fgf21

Fibroblast growth factor 21 (FGF21), a metabolism regulator, has an important effect on metabolic diseases, such as obesity and diabetes. It is also expressed in mice, and the murine source has high homology with human FGF21. Recently, it has been extensively studied and has become a potential drug target for the treatment of metabolic diseases. As it is a protein-based hormone, FGF21 cannot be easily and quickly absorbed into the blood through oral administration. Moreover, it has a 0-2 h half-life in vivo, as shown in a previous study, thus its efficacy lasts for a short period of time when used to treat metabolic diseases, limiting its clinical applications. To avoid these limitations, we used Lactococcus lactis, a food-grade bacterium, as the host to express FGF21. It could be used successfully for the expression and long-term effect of FGF21 in vivo. Instead of antibiotic resistance genes, the LacF gene was used as a selection marker in the NZ3900/PNZ8149 expression system, which is safe and could reduce the antibiotic resistance crisis. In this study, we a constructed human FGF21 expressing L. lactis strain and administered it to Db/Db mice by gavage. Compared with the control group, the body weight of mice in the experimental group was significantly reduced, and the overall homeostasis was improved in mice treated with human FGF21. Moreover, the activity of brown adipose tissue was enhanced. These results revealed that oral administration of FGF21 through heterologous expression in L. lactis appears to be an effective approach for its clinical application.

scholarly journals Dopamine receptor D1- and D2-agonists do not spark brown adipose tissue thermogenesis in mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Francesca-Maria Raffaelli ◽  
Julia Resch ◽  
Rebecca Oelkrug ◽  
K. Alexander Iwen ◽  
Jens Mittag
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Dopamine Receptor ◽  
Ex Vivo ◽  
Potential Target ◽  
D2 Agonist ◽  
Obesity And Diabetes ◽  
Brown Adipose

AbstractBrown adipose tissue (BAT) thermogenesis is considered a potential target for treatment of obesity and diabetes. In vitro data suggest dopamine receptor signaling as a promising approach; however, the biological relevance of dopamine receptors in the direct activation of BAT thermogenesis in vivo remains unclear. We investigated BAT thermogenesis in vivo in mice using peripheral administration of D1-agonist SKF38393 or D2-agonist Sumanirole, infrared thermography, and in-depth molecular analyses of potential target tissues; and ex vivo in BAT explants to identify direct effects on key thermogenic markers. Acute in vivo treatment with the D1- or D2-agonist caused a short spike or brief decrease in BAT temperature, respectively. However, repeated daily administration did not induce lasting effects on BAT thermogenesis. Likewise, neither agonist directly affected Ucp1 or Dio2 mRNA expression in BAT explants. Taken together, the investigated agonists do not seem to exert lasting and physiologically relevant effects on BAT thermogenesis after peripheral administration, demonstrating that D1- and D2-receptors in iBAT are unlikely to constitute targets for obesity treatment via BAT activation.

Inhibition of Type 1 Iodothyronine Deiodinase by Bisphenol A

2019 ◽  
Vol 51 (10) ◽  
pp. 671-677 ◽  
Author(s):  
Maurício Martins da Silva ◽  
Carlos Frederico Lima Gonçalves ◽  
Leandro Miranda-Alves ◽  
Rodrigo Soares Fortunato ◽  
Denise P. Carvalho ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Thyroid Hormone ◽  
Bisphenol A ◽  
Brown Adipose Tissue ◽  
Tissue Type ◽  
Deiodinase Activity ◽  
Brown Adipose

AbstractPlastics are ubiquitously present in our daily life and some components of plastics are endocrine-disrupting chemicals, such as bisphenol A and phthalates. Herein, we aimed to evaluate the effect of plastic endocrine disruptors on type 1 and type 2 deiodinase activities, enzymes responsible for the conversion of the pro-hormone T4 into the biologically active thyroid hormone T3, both in vitro and in vivo. Initially, we incubated rat liver type 1 deiodinase and brown adipose tissue type 2 deiodinase samples with 0.5 mM of the plasticizers, and the deiodinase activity was measured. Among them, only BPA was capable to inhibit both type 1 and type 2 deiodinases. Then, adult male Wistar rats were treated orally with bisphenol A (40 mg/kg b.w.) for 15 days and hepatic type 1 deiodinase and brown adipose tissue type 2 deiodinase activities and serum thyroid hormone concentrations were measured. In vivo bisphenol A treatment significantly reduced hepatic type 1 deiodinase activity but did not affect brown adipose tissue type 2 deiodinase activity. Serum T4 levels were higher in bisphenol A group, while T3 remained unchanged. T3/T4 ratio was decreased in rats treated with bisphenol A, reinforcing the idea that peripheral metabolism of thyroid hormone was affected by bisphenol A exposure. Therefore, our results suggest that bisphenol A can affect the metabolism of thyroid hormone thus disrupting thyroid signaling.

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