Abstract 435: Brown Adipose Tissue Activation in the Postprandial State Reflects on Plasma Lipoproteins and Immune Cell Response in Humans

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Alexandra Mellerowicz ◽  
Madelene Ericsson ◽  
Mattias Hedlund ◽  
Stefan K Nilsson
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cell Response ◽  
Immune Cell ◽  
Plasma Lipoproteins ◽  
Emg Activity ◽  
Cold Stimulation ◽  
Postprandial State ◽  
Brown Adipose ◽  
Immune Cell Response

Background: Brown adipose tissue (BAT) has a unique to ability to use excess energy for heat production. It is therefore an attractive target organ for counteracting obesity and related metabolic diseases where overfeeding is an underlying cause. BAT has in murine models been shown to clear postprandial lipids quickly. The postprandial response is associated to systemic inflammatory alterations and an increased lipid pressure possibly driving atherosclerosis development. We hypothesized that BAT activation would affect postprandial lipid clearance and that this would reflect in an altered immune cell response. Methods: Young male volunteers were subject to an oral fat tolerance test at two separate occasions during both cold stimulation and in thermoneutral control conditions. Body temperature and EMG activity was monitored and energy expenditure (EE) was measured. Blood samples were taken at baseline and every 30 min for 2 h. Plasma lipids and the immune cell response. Results: Cold stimulation during OFTT resulted in a 19,4 % higher EE compared to warm conditions (P=0,007). Surprisingly, no changes in plasma TG were observed. A 2-fold elevation in free fatty acids (FFA) was seen in cold which also correlated positively with EE (P=0,008). Total plasma cholesterol increased compared to warm conditions by 0,56 mmol/L (P=0,050). LDL-c and HDL-c were increased in cold (0,20 mmol/L difference P=0,048 and 0,16 mmol/L P=0,002) whereas remnant-c was unaltered between the two thermal conditions. White blood cell count (WBC) after OFTT was significantly increased in cold (P = 0,018) by 0,29 х 109/L. Discussion: BAT activation in the postprandial state results in increased HDL-c, possibly indicating increased vascular lipolysis and associated pre-β HDL particle formation. Increased VLDL production due to elevated FFA levels in the cold state and might explain why plasma TG is unaltered and also why LDL-c remains at a higher concentration in the cold. Conclusions: BAT might be an attractive target for obesity treatment but potentially displays pro-atherogenic properties that must be addressed in longitudinal studies.

scholarly journals Multimodal Imaging for the Detection of Brown Adipose Tissue Activation in Women: A Pilot Study Using NIRS and Infrared Thermography

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Valentina Hartwig ◽  
Letizia Guiducci ◽  
Martina Marinelli ◽  
Laura Pistoia ◽  
Tommaso Minutoli Tegrimi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Pilot Study ◽  
Brown Adipose Tissue ◽  
Infrared Thermography ◽  
Pharmacological Intervention ◽  
Oral Glucose ◽  
Cold Stimulation ◽  
Standard Clinical Practice ◽  
Obesity And Diabetes ◽  
Brown Adipose

Purpose. A clear link between obesity and brown adipose tissue (BAT) dysfunction has been recently demonstrated. The purpose of this pilot study is to determine if near-infrared spectroscopy (NIRS) 2D imaging together with infrared thermography (IRT) is capable of identifying thermal and vascular response in the supraclavicular (SCV) areas after the ingestion of an oral glucose load as a thermogenic stimulation. Method. We studied two groups of women (obese versus lean) for discerning their different responses. NIRS and IRT images were acquired on the neck in the left SCV region during a 3 h oral glucose tolerance test (OGTT) and immediately after a cold stimulation. Results. We detected a significant thermal response of BAT in SCV fossa in both groups. Both during OGTT and after cold stimulation, skin temperature was persistently higher in lean versus obese. This response was not coupled with changes in oxygen saturation of subcutaneous tissue in that area. Discussion and Conclusion. The results show that NIRS/IRT may be a novel, noninvasive, radiation-free, easy to use, and low-cost method for monitoring, during the standard clinical practice, the diet and pharmacological intervention which aims to stimulate BAT as a potential therapeutic target against obesity and diabetes.

Enhanced gene expression of endothelial nitric oxide synthase in brown adipose tissue during cold exposure

2002 ◽  
Vol 282 (2) ◽  
pp. R623-R626 ◽  
Author(s):  
Kazue Kikuchi-Utsumi ◽  
Bihu Gao ◽  
Hiroshi Ohinata ◽  
Masaaki Hashimoto ◽  
Noriyuki Yamamoto ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Inos Mrna ◽  
No Production ◽  
Mrna Levels ◽  
Cold Stimulation ◽  
Brown Adipose ◽  
Enos Mrna

It has been shown that norepinephrine (NE) can mediate vasodilatation by stimulating the production of nitric oxide (NO) in brown adipose tissue (BAT), resulting in an increase in BAT blood flow. We speculated that constitutive NO synthase (NOS) is involved in this NO production. However, it is not known whether constitutive NOS is expressed in BAT. To answer this question, we assessed the expression of two types of constitutive NOS, endothelial (eNOS) and neuronal NOS (nNOS), in BAT of rats. eNOS was abundantly expressed in both BAT and isolated brown adipocytes, whereas nNOS was not. Cold exposure, which is known to stimulate NE release from sympathetic nerve terminals in BAT, led to a significant increase in eNOS mRNA in this tissue. In contrast, very low levels of inducible NOS (iNOS) mRNA were expressed, and cold stimulation failed to increase iNOS mRNA levels in BAT. These results suggest that eNOS is the primary isoform that is responsible for NO production in BAT and that its expression may be under sympathetic control.

scholarly journals ACE2 Pathway Regulates Thermogenesis and Energy Metabolism

2021 ◽  
Author(s):  
Xi Cao ◽  
Tingting Shi ◽  
Chuanhai Zhang ◽  
Wanzhu Jin ◽  
Lini Song ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Knockout Mice ◽  
Metabolic Disorders ◽  
Energy Homeostasis ◽  
Cold Stimulation ◽  
Obesity And Diabetes ◽  
Brown Adipose ◽  
Pka Pathway

Identification of key regulators of energy homeostasis holds important therapeutic promise for metabolic disorders, such as obesity and diabetes. ACE2 cleaves angiotensin II (Ang II) to generate Ang-(1-7) which acts mainly through the Mas receptor. Here, we identify ACE2 pathway as a critical regulator in the maintenance of thermogenesis and energy expenditure. We found that ACE2 is highly expressed in brown adipose tissue (BAT) and that cold stimulation increases ACE2 and Ang-(1-7) levels in BAT and serum. ACE2 knockout mice (ACE2-/y), Mas knockout mice (Mas-/-), and the mice transplanted with brown adipose tissue from Mas-/- mice displayed impaired thermogenesis. In contrast, impaired thermogenesis of db/db obese diabetic mice and high-fat diet-induced obese mice were ameliorated by overexpression of ACE2 or continuous infusion of Ang-(1-7). Activation of ACE2 pathway was associated with improvement of metabolic parameters, including blood glucose, lipids and energy expenditure in multiple animal models. Consistently, ACE2 pathway remarkably enhanced the browning of white adipose tissue. Mechanistically, we showed that ACE2 pathway activated Akt/FoxO1 and PKA pathway, leading to induction of UCP1 and activation of mitochondrial function. Our data propose that adaptive thermogenesis requires regulation of ACE2 pathway and highlight novel therapeutic targets for the treatment of metabolic disorders.

scholarly journals Brown Adipose Crosstalk in Tissue Plasticity and Human Metabolism

2019 ◽  
Vol 41 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Camilla Scheele ◽  
Christian Wolfrum
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Metabolic Regulation ◽  
Immune Cell ◽  
Primary Source ◽  
Whole Body ◽  
Brown Adipose ◽  
The Central Nervous System

Abstract Infants rely on brown adipose tissue (BAT) as a primary source of thermogenesis. In some adult humans, residuals of brown adipose tissue are adjacent to the central nervous system and acute activation increases metabolic rate. Brown adipose tissue (BAT) recruitment occurs during cold acclimation and includes secretion of factors, known as batokines, which target several different cell types within BAT, and promote adipogenesis, angiogenesis, immune cell interactions, and neurite outgrowth. All these processes seem to act in concert to promote an adapted BAT. Recent studies have also provided exciting data on whole body metabolic regulation with a broad spectrum of mechanisms involving BAT crosstalk with liver, skeletal muscle, and gut as well as the central nervous system. These widespread interactions might reflect the property of BAT of switching between an active thermogenic state where energy is highly consumed and drained from the circulation, and the passive thermoneutral state, where energy consumption is turned off. (Endocrine Reviews 41: XXX – XXX, 2020)

scholarly journals In vivoassessment of cold stimulation effects on the fat fraction of brown adipose tissue using DIXON MRI

2016 ◽  
Vol 45 (2) ◽  
pp. 369-380 ◽  
Author(s):  
Vanessa Stahl ◽  
Florian Maier ◽  
Martin T. Freitag ◽  
Ralf O. Floca ◽  
Moritz C. Berger ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Stimulation ◽  
Brown Adipose ◽  
Fat Fraction

scholarly journals ACE2 pathway regulates thermogenesis and energy metabolism

eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Xi Cao ◽  
Tingting Shi ◽  
Chuanhai Zhang ◽  
Wanzhu Jin ◽  
Lini Song ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Knockout Mice ◽  
Metabolic Disorders ◽  
Energy Homeostasis ◽  
Cold Stimulation ◽  
Obesity And Diabetes ◽  
Brown Adipose ◽  
Pka Pathway

Identification of key regulators of energy homeostasis holds important therapeutic promise for metabolic disorders, such as obesity and diabetes. ACE2 cleaves angiotensin II (Ang II) to generate Ang-(1-7) which acts mainly through the Mas1 receptor. Here, we identify ACE2 pathway as a critical regulator in the maintenance of thermogenesis and energy expenditure. We found that ACE2 is highly expressed in brown adipose tissue (BAT) and that cold stimulation increases ACE2 and Ang-(1-7) levels in BAT and serum. Ace2 knockout mice (Ace2-/y) and Mas1 knockout mice (Mas1-/-) displayed impaired thermogenesis. Mice transplanted with brown adipose tissue from Mas1-/- display metabolic abnormalities consistent with those seen in the Ace2 and Mas1 knockout mice. In contrast, impaired thermogenesis of Leprdb/db obese diabetic mice and high-fat diet-induced obese mice were ameliorated by overexpression of Ace2 or continuous infusion of Ang-(1-7). Activation of ACE2 pathway was associated with improvement of metabolic parameters, including blood glucose, lipids and energy expenditure in multiple animal models. Consistently, ACE2 pathway remarkably enhanced the browning of white adipose tissue. Mechanistically, we showed that ACE2 pathway activated Akt/FoxO1 and PKA pathway, leading to induction of UCP1 and activation of mitochondrial function. Our data propose that adaptive thermogenesis requires regulation of ACE2 pathway and highlight novel potential therapeutic targets for the treatment of metabolic disorders.

scholarly journals Brown Adipose Tissue Response to Cold Stimulation Is Reduced in Girls With Autoimmune Hypothyroidism

2019 ◽  
Vol 3 (12) ◽  
pp. 2411-2426 ◽  
Author(s):  
James M Law ◽  
David E Morris ◽  
Valerie Astle ◽  
Ellie Finn ◽  
José Joaquín Muros ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Disease Process ◽  
Tissue Response ◽  
Healthy Controls ◽  
Thyroid Status ◽  
Cold Stimulation ◽  
Autoimmune Hypothyroidism ◽  
Bat Activity ◽  
Brown Adipose

Abstract Objective The interaction between thyroid status and brown adipose tissue (BAT) activation is complex. We assessed the effect of autoimmune hypothyroidism (ATD) in female children on BAT activation, measured using infrared thermography. Design Twenty-six female participants (14 with ATD and 12 healthy controls) between 5 and 17 years of age attended a single study session. Thermal images were taken of the supraclavicular region before, and after, the introduction of a cool stimulus. Results Participants with ATD had lower resting (hypothyroid, 34.9 ± 0.7°C; control, 35.4 ± 0.5°C; P = 0.03) and stimulated (hypothyroid, 35.0 ± 0.6°C; control, 35.5 ± 0.5°C; P = 0.04) supraclavicular temperatures compared with controls, but there was no difference between groups in the temperature increase with stimulation. BAT activation, calculated as the relative temperature change comparing the supraclavicular temperature to a sternal reference region, was reduced in participants with ATD (hypothyroid, 0.1 ± 0.1°C; control, 0.2 ± 0.2°C; P = 0.04). Children with ATD were frequently biochemically euthyroid due to replacement therapy, but, despite this, increased relative supraclavicular temperature was closely associated with increased TSH (r = 0.7, P = 0.01) concentrations. Conclusions Girls with ATD had an attenuated thermogenic response to cold stimulation compared with healthy controls, but, contrary to expectation, those with suboptimal biochemical control (with higher TSH) showed increased BAT activation. This suggests that the underlying disease process may have a negative effect on BAT response, but high levels of TSH can mitigate, and even stimulate, BAT activity. In summary, thyroid status is a complex determinant of BAT activity in girls with ATD.

scholarly journals Effect of Liothyronine Treatment on Dermal Temperature and Activation of Brown Adipose Tissue in Female Hypothyroid Patients: A Randomized Crossover Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Betty Ann Bjerkreim ◽  
Sara Salehi Hammerstad ◽  
Hanne Løvdal Gulseth ◽  
Tore Julsrud Berg ◽  
Sindre Lee-Ødegård ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Crossover Study ◽  
Skin Temperature ◽  
Secondary Outcome ◽  
Clinical Trial Registration ◽  
Cold Stimulation ◽  
Cold Intolerance ◽  
Brown Adipose ◽  
Hypothyroid Patients

BackgroundThyroid hormones are essential for the full thermogenic response of brown adipose tissue (BAT) and have been implicated in dermal temperature regulation. Nevertheless, persistent cold-intolerance exists among a substantial proportion of hypothyroid patients on adequate levothyroxine (LT4) substitution.Materials and MethodsTo assess if skin temperature and activation of BAT during treatment with liothyronine (LT3) differs from that of LT4 treatment, fifty-nine female hypothyroid patients with residual symptoms on LT4 or LT4/LT3 combination therapy were randomly assigned in a non-blinded crossover study to receive monotherapy with LT4 or LT3 for 12 weeks each. Change in supraclavicular (SCV) skin temperature overlying BAT, and sternal skin temperature not overlying BAT, during rest and cold stimulation were assessed by infrared thermography (IRT). In addition, abundance of exosomal miR-92a, a biomarker of BAT activation, was estimated as a secondary outcome.ResultsCold stimulated skin temperatures decreased less with LT3 vs. LT4 in both SCV (mean 0.009°C/min [95% CI: 0.004, 0.014]; P<0.001) and sternal areas (mean 0.014°C/min [95% CI: 0.008, 0.020]; P<0.001). No difference in serum exosomal miR-92a abundance was observed between the two treatment groupsConclusionLT3 may reduce dermal heat loss. Thermography data suggested increased BAT activation in hypothyroid patients with cold-intolerance. However, this finding was not corroborated by assessment of the microRNA biomarker of BAT activation.Clinical Trial RegistrationClinicalTrials.gov, identifier NCT03627611

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