scholarly journals Isothermal microcalorimetry measures UCP1-mediated thermogenesis in mature brite adipocytes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Hamza Bokhari ◽  
Carina Halleskog ◽  
Alice Åslund ◽  
Nathalie Boulet ◽  
Eva Casadesús Rendos ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Heat Production ◽  
Isothermal Microcalorimetry ◽  
Human Origin ◽  
Essential Component ◽  
Important Target ◽  
Lower Extent

AbstractThe activation of thermogenesis in adipose tissue has emerged as an important target for the development of novel anti-obesity therapies. Using multi-well isothermal microcalorimetry, we have demonstrated that mature murine brown and brite adipocytes produce quantifiable heat upon β3-AR stimulation, independently of any anaerobic mechanisms. Additionally, in brite adipocytes lacking UCP1 protein, β3-AR stimulation still induces heat production, albeit to a much lower extent than in their wildtype counterparts, suggesting that UCP1 is an essential component of adrenergic induced thermogenesis in murine brite adipocytes exvivo. Similarly, we could observe an increase in heat production in human-derived adipocytes (hMADS) upon β-AR stimulation. Collectively, these results establish the use of isothermal microcalorimetry as a sensitive and accurate technique for measuring thermogenic responses in intact mature brite adipocytes from murine and human origin.

scholarly journals Plasticity of non-shivering thermogenesis and brown adipose tissue in high-altitude deer mice

2021 ◽  
Author(s):  
Soren Z. Coulson ◽  
Cayleih E. Robertson ◽  
Sajeni Mahalingam ◽  
Grant B. McClelland
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
High Altitude ◽  
Heat Production ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Deer Mice ◽  
Brown Adipose ◽  
Hypoxia Acclimation ◽  
Shivering Thermogenesis

High altitude environments challenge small mammals with persistent low ambient temperatures that require high rates of aerobic heat production in face of low O2 availability. An important component of thermogenic capacity in rodents is non-shivering thermogenesis (NST) mediated by uncoupled mitochondrial respiration in brown adipose tissue (BAT). NST is plastic, and capacity for heat production increases with cold acclimation. However, in lowland native rodents, hypoxia inhibits NST in BAT. We hypothesize that highland deer mice (Peromyscus maniculatus) overcome the hypoxic inhibition of NST through changes in BAT mitochondrial function. We tested this hypothesis using lab born and raised highland and lowland deer mice, and a lowland congeneric (P. leucopus), acclimated to either warm normoxia (25°C, 760 mmHg) or cold hypoxia (5°C, 430 mmHg). We determined the effects of acclimation and ancestry on whole-animal rates of NST, the mass of interscapular BAT (iBAT), and uncoupling protein (UCP)-1 protein expression. To identify changes in mitochondrial function, we conducted high-resolution respirometry on isolated iBAT mitochondria using substrates and inhibitors targeted to UCP-1. We found that rates of NST increased with cold hypoxia acclimation but only in highland deer mice. There was no effect of cold hypoxia acclimation on iBAT mass in any group, but highland deer mice showed increases in UCP-1 expression and UCP-1 stimulated mitochondrial respiration in response to these stressors. Our results suggest that highland deer mice have evolved to increase the capacity for NST in response to chronic cold hypoxia, driven in part by changes in iBAT mitochondrial function.

Hypothalamic obesity, brown adipose tissue, and sympathoadrenal activity in rats

1985 ◽  
Vol 248 (5) ◽  
pp. E607-E617 ◽  
Author(s):  
J. G. Vander Tuig ◽  
J. Kerner ◽  
D. R. Romsos
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Adult Rats ◽  
Guanosine Diphosphate ◽  
Bat Mitochondria ◽  
Sympathoadrenal Activity ◽  
Brown Adipose ◽  
Energy Retention ◽  
Ad Libitum

Obesity-producing, hypothalamic knife cuts and ventromedial hypothalamic (VMH) lesions in ad libitum-fed adult rats increased intake of a high-fat diet (123 and 130%) and energy retention (880 and 1,099%) during the 4-wk period postsurgery; even when pair fed to control rats, energy retention of the knife-cut and lesioned rats was still elevated (105 and 155%). Thermogenic capacity of brown adipose tissue (BAT), estimated from guanosine diphosphate (GDP) binding to BAT mitochondria, was unchanged in hyperphagic knife-cut and VMH-lesioned rats and was reduced approximately 50% when these rats were pair fed to controls. Urinary excretion of norepinephrine (NE) was approximately twofold higher in ad libitum-fed, knife-cut, and lesioned rats than in control rats; restriction of energy intake decreased NE excretion to control values. Rates of NE turnover in heart paralleled urinary NE excretion, whereas NE turnover in BAT was generally not increased in the hyperphagic rats. Urinary epinephrine excretion, an index of adrenal medullary activity, was depressed in all knife-cut and VMH-lesioned rats. Hyperphagia coupled with a lack of increased heat production in BAT causes gross obesity in ad libitum-fed, knife-cut, and VMH-lesioned rats, whereas obesity in pair-fed rats develops in part at least as a result of reduced heat production by BAT.

Brown Adipose Tissue: Function and Physiological Significance

2004 ◽  
Vol 84 (1) ◽  
pp. 277-359 ◽  
Author(s):  
BARBARA CANNON ◽  
JAN NEDERGAARD
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Uncoupling Protein ◽  
Sympathetic Nerves ◽  
Physiological Significance ◽  
Metabolic Efficiency ◽  
Transfer Energy ◽  
Brown Adipose ◽  
Evolutionary Success

Cannon, Barbara, and Jan Nedergaard. Brown Adipose Tissue: Function and Physiological Significance. Physiol Rev 84: 277–359, 2004; 10.1152/physrev.00015.2003.—The function of brown adipose tissue is to transfer energy from food into heat; physiologically, both the heat produced and the resulting decrease in metabolic efficiency can be of significance. Both the acute activity of the tissue, i.e., the heat production, and the recruitment process in the tissue (that results in a higher thermogenic capacity) are under the control of norepinephrine released from sympathetic nerves. In thermoregulatory thermogenesis, brown adipose tissue is essential for classical nonshivering thermogen-esis (this phenomenon does not exist in the absence of functional brown adipose tissue), as well as for the cold acclimation-recruited norepinephrine-induced thermogenesis. Heat production from brown adipose tissue is activated whenever the organism is in need of extra heat, e.g., postnatally, during entry into a febrile state, and during arousal from hibernation, and the rate of thermogenesis is centrally controlled via a pathway initiated in the hypothalamus. Feeding as such also results in activation of brown adipose tissue; a series of diets, apparently all characterized by being low in protein, result in a leptin-dependent recruitment of the tissue; this metaboloregulatory thermogenesis is also under hypothalamic control. When the tissue is active, high amounts of lipids and glucose are combusted in the tissue. The development of brown adipose tissue with its characteristic protein, uncoupling protein-1 (UCP1), was probably determinative for the evolutionary success of mammals, as its thermogenesis enhances neonatal survival and allows for active life even in cold surroundings.

scholarly journals Association of Heat Production with 18F-FDG Accumulation in Murine Brown Adipose Tissue After Stress

2011 ◽  
Vol 52 (10) ◽  
pp. 1616-1620 ◽  
Author(s):  
E. A. Carter ◽  
A. A. Bonab ◽  
K. Paul ◽  
J. Yerxa ◽  
R. G. Tompkins ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Brown Adipose ◽  
18F Fdg ◽  
Fdg Accumulation

scholarly journals Adipose tissue and heat production in the new-born ox (Bos taurus)

1968 ◽  
Vol 195 (3) ◽  
pp. 639-646 ◽  
Author(s):  
D. McEwan Jenkinson ◽  
R. C. Noble ◽  
G. E. Thompson
Keyword(s):  
Adipose Tissue ◽  
Heat Production ◽  
Bos Taurus ◽  
New Born

scholarly journals Adipocytes and microRNAs Crosstalk: A Key Tile in the Mosaic of Breast Cancer Microenvironment

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1451 ◽  
Author(s):  
Erika Bandini ◽  
Tania Rossi ◽  
Giulia Gallerani ◽  
Francesco Fabbri
Keyword(s):  
Breast Cancer ◽  
Adipose Tissue ◽  
Immune Cells ◽  
Tumor Suppressor Genes ◽  
Breast Tissue ◽  
Molecular Mechanisms ◽  
Important Target ◽  
New Concepts ◽  
Clinical Strategies

Breast cancer (BC) is a disease characterized by a high grade of heterogeneity. Consequently, despite the great achievements obtained in the last decades, most of the current therapeutic regimens still fail. The identification of new molecular mechanisms that will increase the knowledge of all steps of tumor initiation and growth is mandatory in finding new clinical strategies. The BC microenvironment, consisting of endothelial cells, fibroblasts, immune cells and adipocytes, plays an essential role in regulating BC development, and recently it has gained great attention in the scientific community. In particular, adipose tissue is emerging as an important target to investigate among mammary gland components. The mechanisms underlying BC progression driven by adipocytes are predominantly unexplored, especially that involving the switch from normal adipocytes to the so-called cancer-associated adipocytes (CAAs). MicroRNAs (miRNAs), a class of gene expression modulators, have emerged as the regulators of key oncogenes and tumor suppressor genes that affect multiple pathways of the tumor microenvironment and adipose tissue. This review concerns a presentation of the role of adipocytes in breast tissue, and describes the most recent discoveries about the interplay between adipocytes and miRNAs, which collaborate in the arrangement of a pro-inflammatory and cancerous microenvironment, laying the foundations for new concepts in the prevention and treatment of BC.

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