Brown adipose tissue mapping in rats with combined intermolecular double‐quantum coherence and Dixon water–fat MRI

Bao, Jianfeng; Cui, Xiaohong; Cai, Shuhui; Zhong, Jianhui; Cai, Congbo; Chen, Zhong

doi:10.1002/nbm.3000

Cited by 19 publications

(17 citation statements)

References 29 publications

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“…Few studies have employed MRI and MRS techniques to detect WAT and BAT, taking advantage of their marked difference in water/fat ratio (46‐50). BAT is known to have a higher water content than WAT (48). To confirm the occurrence of browning in vivo , we performed MRS analysis of the water over CH 3 lipid signal at 0.9 ppm in the inguinal fat depot.…”

Section: Resultsmentioning

confidence: 99%

Mineralocorticoid receptor antagonism induces browning of white adipose tissue through impairment of autophagy and prevents adipocyte dysfunction in high‐fat‐diet‐fed mice

et al. 2014

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The mineralocorticoid receptor (MR) controls adipocyte function, but its role in the conversion of white adipose tissue (WAT) into thermogenic fat has not been elucidated. We investigated responses to the MR antagonists spironolactone (spiro; 20 mg/kg/d) and drospirenone (DRSP; 6 mg/kg/d) in C57BL/6 mice fed a high-fat (HF) diet for 90 d. DRSP and spiro curbed HF diet-induced impairment in glucose tolerance, and prevented body weight gain and white fat expansion. Notably, either MR antagonist induced up-regulation of brown adipocyte-specific transcripts and markedly increased protein levels of uncoupling protein 1 (UCP1) in visceral and inguinal fat depots when compared with the HF diet group. Positron emission tomography and magnetic resonance spectroscopy confirmed acquisition of brown fat features in WAT. Interestingly, MR antagonists markedly reduced the autophagic rate both in murine preadipocytes in vitro (10(-5) M) and in WAT depots in vivo, with a concomitant increase in UCP1 protein expression. Moreover, the autophagy repressor bafilomycin A1 (10(-8) M) mimicked the effect of MR antagonists, increasing UCP1 protein expression in primary preadipocytes. Hence, we showed that adipocyte MR regulates brown remodeling of WAT through a modulation of autophagy. These results provide a rationale for the use of MR antagonists to prevent the adverse metabolic consequences of adipocyte dysfunction.

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Section: Resultsmentioning

confidence: 99%

Mineralocorticoid receptor antagonism induces browning of white adipose tissue through impairment of autophagy and prevents adipocyte dysfunction in high‐fat‐diet‐fed mice

et al. 2014

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“…A quantitative cross-peak originating from a flip-flip or flip-flop transition can be observed in the two-dimensional MR spectra. Furthermore, a combination of intermolecular double-quantum coherence with a chemical shift encoded Dixon method has recently been reported by Bao et al (18). The feasibility of intermolecular methodologies has apparently been verified, but the low sensitivity issue has yet to be resolved, especially for human imaging (16).…”

Section: Nmr Data Acquisition and Analysismentioning

confidence: 99%

Differentiating brown and white adipose tissues by high-resolution diffusion NMR spectroscopy

Verma

Nagashima

Yaligar

et al. 2017

Journal of Lipid Research

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majority of body fat, which is utilized for energy storage, whereas BAT is a minor portion that is involved in thermogenesis, due to the presence of uncoupling protein 1 (UCP1) in the mitochondria. In addition to the differences in energy storage and expenditure, BAT is a highly heterogeneous, densely vascularized tissue with abundant oxygen, blood supply, and iron-rich mitochondria (6, 7). WAT is composed of unilocular lipid droplets, whereas BAT is composed of multilocular lipid droplets scattered throughout the cytoplasm and surrounded by mitochondria.Positron emission tomography (PET) has been the gold standard for imaging BAT (8, 9) because of a selective image contrast of activated BAT by the increased uptake of 18 F-deoxyglucose. However, PET is not suitable for longitudinal studies because it requires injection of exogenous radioactive tracers. Magnetic resonance (MR)-based methods are more promising for real-time and long-term observation of fat accumulation and consumption (10). Traditional MR-based approaches exploit the differences in the water content in WAT and BAT using chemical shift imaging or the Dixon technique (11-13). Imaging of water and fat permits quantitative assessment of the fat fraction. Additionally, the differences in iron content, perfusion, and vasculature have been exploited by T 2 and T 2 * relaxation techniques (14, 15). However, although WAT and BAT are manually separable by color and texture, they cannot be easily distinguished by MR because of the similarity in their magnetic and chemical characteristics (14,15).Applications of nontraditional MR methodologies for selectively detecting BAT have been attempted. Branca and Warren (16, 17) have studied focusing on intermolecular multiple-quantum coherences through dipolar Abstract There are two types of fat tissues, white adipose tissue (WAT) and brown adipose tissue (BAT), which essentially perform opposite functions in whole body energy metabolism. There is a large interest in identifying novel biophysical properties of WAT and BAT by a quantitative and easy-to-run technique. In this work, we used high-resolution pulsed field gradient diffusion NMR spectroscopy to study the apparent diffusion coefficient (ADC) of fat molecules in rat BAT and WAT samples. The ADC of fat in BAT and WAT from rats fed with a chow diet was compared with that of rats fed with a high-fat diet to monitor how the diffusion properties change due to obesity-associated parameters such as lipid droplet size, fatty acid chain length, and saturation. Feeding a high-fat diet resulted in increased saturation, increased chain lengths, and reduced ADC of fat in WAT. The ADC of fat was lower in BAT relative to WAT in rats fed both chow and high-fat diets. Diffusion of fat was restricted in BAT due to the presence of small multilocular lipid droplets. Our findings indicate that in vivo diffusion might be a potential way for better delineation of BAT and WAT in both lean and obese states.-Verma, S. K., K. Nagashima, J. Yaligar, N. Michael, S. S. Lee, T. Xianfeng, V...

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“…The technique can be considered sensitive to dipole-dipole interactions that occur over long distances (ßμm to mm) and the distance over which the technique is sensitive can be tuned using a magnetic field gradient. This approach has been successfully used to discern BAT from WAT in rodents and map BAT (Branca & Warren, 2011;Bao et al 2013;Branca et al 2013).…”

Section: [F]-fluorobenzyltryphenyl Phosphonium ( F-fbntp)-mentioning

confidence: 99%

“…This approach has been successfully used to discern BAT from WAT in rodents and map BAT (Branca & Warren, ; Bao et al . ; Branca et al . ).…”

Section: Introductionmentioning

confidence: 99%

Non‐invasive methods for the assessment of brown adipose tissue in humans

Chondronikola

Beeman

Wahl

2018

The Journal of Physiology

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Brown adipose tissue (BAT) is a recently rediscovered tissue in people that has shown promise as a potential therapeutic target against obesity and its metabolic abnormalities. Reliable non-invasive assessment of BAT volume and activity is critical to allow its importance in metabolic control to be evaluated. Positron emission tomography/computed tomography (PET/CT) in combination with 2-deoxy-2-[ F]fluoroglucose administration is currently the most frequently used and most established method for the detection and quantification of activated BAT in humans. However, it involves radiation exposure and can detect activated (e.g. after cold exposure), but not quiescent, BAT. Several alternative methods that overcome some of these limitations have been developed including different PET approaches, single-photon emission imaging, CT, magnetic resonance based approaches, contrast-enhanced ultrasound, near infrared spectroscopy, and temperature assessment of fat depots containing brown adipocytes. The purpose of this review is to summarize and critically evaluate the currently available methods that non-invasively probe various aspects of BAT biology in order to assess BAT volume and/or metabolism. Although several of these methods show promise for the non-invasive assessment of BAT volume and function, further research is needed to optimize them to enable an accurate, reproducible and practical means for the assessment of human BAT content and its metabolic function.

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Brown adipose tissue mapping in rats with combined intermolecular double‐quantum coherence and Dixon water–fat MRI

Cited by 19 publications

References 29 publications

Mineralocorticoid receptor antagonism induces browning of white adipose tissue through impairment of autophagy and prevents adipocyte dysfunction in high‐fat‐diet‐fed mice

Mineralocorticoid receptor antagonism induces browning of white adipose tissue through impairment of autophagy and prevents adipocyte dysfunction in high‐fat‐diet‐fed mice

Differentiating brown and white adipose tissues by high-resolution diffusion NMR spectroscopy

Non‐invasive methods for the assessment of brown adipose tissue in humans

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