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.

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 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 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.

Relation of Diet-Induced Thermogenesis to Brown Adipose Tissue Activity in Healthy Men

2020 ◽  
Author(s):  
Rahel Catherina Loeliger ◽  
Claudia Irene Maushart ◽  
Gani Gashi ◽  
Jaël Rut Senn ◽  
Martina Felder ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Healthy Men ◽  
Bat Activity ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis

Objective Human brown adipose tissue (BAT) is a thermogenic tissue activated by the sympathetic nervous system in response to cold. It contributes to energy expenditure (EE) and takes up glucose and lipids from the circulation. Studies in rodents suggest that BAT contributes to the transient rise in EE after food intake, so called diet-induced thermogenesis (DIT). We investigated the relationship between human BAT activity and DIT in response to glucose intake in 17 healthy volunteers. Methods We assessed DIT, cold induced thermogenesis (CIT) and maximum BAT activity at three separate study visits within two weeks. DIT was measured by indirect calorimetry during an oral glucose tolerance-test. CIT was assessed as the difference in EE after cold exposure of two hours duration as compared to warm conditions. Maximal activity of BAT was assessed by 18F-FDG-PET/MRI after cold exposure and concomitant pharmacological stimulation with Mirabegron. Results 17 healthy men (mean age 23.4 years, mean BMI 23.2 kg/m2) participated in the study. EE increased from 1908 (±181) kcal/24 hours to 2128 (±277) kcal/24 hours (p<0.0001, +11.5%) after mild cold exposure. An oral glucose load increased EE from 1911 (±165) kcal/24 hours to 2096 (±167) kcal/24 hours at 60 minutes (p<0.0001, +9.7%). The increase in EE in response to cold was significantly associated with BAT activity (R2=0.43, p=0.004). However, DIT was not associated with BAT activity (R2=0.015, p=0.64). Conclusion DIT after an oral glucose load was not associated with stimulated 18F-FDG uptake into BAT suggesting that DIT is independent from BAT activity in humans.

Transcriptome of the subcutaneous adipose tissue in response to oral supplementation of type 2 Leprdb obese diabetic mice with niacin-bound chromium

2006 ◽  
Vol 27 (3) ◽  
pp. 370-379 ◽  
Author(s):  
Cameron Rink ◽  
Sashwati Roy ◽  
Savita Khanna ◽  
Trenton Rink ◽  
Debasis Bagchi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Blood Glucose ◽  
Specific Gene ◽  
Oral Glucose ◽  
Diabetic Mice ◽  
Fat Tissue ◽  
Obesity And Diabetes ◽  
Brown Adipose

The effects of oral niacin-bound chromium (NBC) supplementation on the subcutaneous fat tissue of type 2 Lepr db obese diabetic mice were examined using high-density comprehensive mouse genome (45,101 probe sets) expression arrays. The influence of such supplementation on the plasma cardiovascular risk factors of these mice was also investigated. Supplementation of NBC had no significant effect on age-dependent weight gain in the Lepr db obese diabetic mice. However, NBC lowered total cholesterol (TC), TC-to-HDL ratio, LDL cholesterol, and triglyceride levels while increasing HDL cholesterol in the blood plasma. No effect of NBC supplementation was observed on fasting blood glucose levels. Oral glucose tolerance test revealed a significantly improved clearance of blood glucose between 1 and 2 h of glucose challenge in NBC-supplemented mice. Unbiased genome-wide interrogation demonstrated that NBC resulted in the upregulation of muscle-specific gene expression in the fat tissue. Genes encoding proteins involved in glycolysis, muscle contraction, muscle metabolism, and muscle development were specifically upregulated in response to NBC supplementation. Genes in the adipose tissue that were downregulated in response to NBC supplementation included cell death-inducing DNA fragmentation factor (CIDEA) and uncoupling protein-1, which represent key components involved in the thermogenic role of brown adipose tissue and tocopherol transfer protein, the primary carrier of α-tocopherol to adipose tissue. The observation that CIDEA-null mice are resistant to obesity and diabetes suggests that the inhibitory role of NBC on CIDEA expression was favorable. Further studies testing the molecular basis of NBC function and long-term outcomes are warranted.

scholarly journals Infrared thermography in the detection of brown adipose tissue in humans

2014 ◽  
Vol 2 (11) ◽  
pp. e12167 ◽  
Author(s):  
Christina Jang ◽  
Sandya Jalapu ◽  
Moe Thuzar ◽  
Phillip W Law ◽  
Susanne Jeavons ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Infrared Thermography ◽  
Brown Adipose

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.

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