Abstract 12631: Peripheral Gamma-aminobutyric Acid(gaba) Signaling in Brown Adipose Tissue Induces Metabolic Dysfunction in Obesity

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Ryutaro Ikegami ◽  
Ippei Shimizu ◽  
Takeshi Sato ◽  
Shuang Jiao ◽  
Yohko Yoshida ◽  
...  
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Function ◽  
Aminobutyric Acid ◽  
Mitochondrial Calcium ◽  
Metabolic Dysfunction ◽  
Gamma Aminobutyric Acid ◽  
Brown Adipose ◽  
Gaba Signaling

Accumulating evidence suggests that adult humans possess active brown adipose tissue (BAT) that may contribute significantly to systemic metabolism because of its high energy consumption capacity. Recently, we demonstrated that metabolic stress induced BAT hypoxia and impaired mitochondrial function, leading to the development of BAT “whitening” and systemic metabolic dysfunction in murine obese models. Various neurotransmitters are known to be involved in the maintenance of BAT homeostasis. Among them, the gamma-aminobutyric acid (GABA) signaling in the central nervous system is well accepted to have anti-obesity effects through the activation of the sympathetic nervous system. Here we show the previously unknown role of peripheral GABA signaling in the development of systemic metabolic dysfunction in obesity. We generated an obese model by imposing a high fat/high sucrose (HFHS) diet on C57BL/6NCr mice. Mass spectrometry analysis demonstrated a significant increase in GABA level in BAT of the dietary obese model. Addition of GABA into drinking water induced BAT whitening, reduced the thermogenic response upon cold tolerance test, and promoted systemic metabolic dysfunction in the obese mice. Mitochondrial calcium is important for the maintenance of mitochondrial homeostasis, whereas calcium overload is reported to inhibit mitochondrial function. Treatment of BAT cells with GABA markedly increased mitochondrial calcium level, promoted the production of reactive oxygen species (ROS), and inhibited mitochondrial respiration. These results indicate that peripheral GABA contributes to the development of systemic metabolic dysfunction by inhibiting BAT function in obesity. The inhibition of peripheral GABA signaling would become a new therapeutic target for obesity and diabetes.

scholarly journals Gamma-Aminobutyric Acid Signaling in Brown Adipose Tissue Promotes Systemic Metabolic Derangement in Obesity

Cell Reports ◽  
2018 ◽  
Vol 24 (11) ◽  
pp. 2827-2837.e5 ◽  
Author(s):  
Ryutaro Ikegami ◽  
Ippei Shimizu ◽  
Takeshi Sato ◽  
Yohko Yoshida ◽  
Yuka Hayashi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Metabolic Derangement ◽  
Brown Adipose

CNS origins of the sympathetic nervous system outflow to brown adipose tissue

1999 ◽  
Vol 276 (6) ◽  
pp. R1569-R1578 ◽  
Author(s):  
Maryam Bamshad ◽  
C. Kay Song ◽  
Timothy J. Bartness
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Sympathetic Nervous System ◽  
Brown Adipose Tissue ◽  
Pseudorabies Virus ◽  
Critical Role ◽  
Hypothalamic Nucleus ◽  
Brown Adipose ◽  
Sympathetic Nervous ◽  
Diet Induced Thermogenesis

Brown adipose tissue (BAT) plays a critical role in cold- and diet-induced thermogenesis. Although BAT is densely innervated by the sympathetic nervous system (SNS), little is known about the central nervous system (CNS) origins of this innervation. The purpose of the present experiment was to determine the neuroanatomic chain of functionally connected neurons from the CNS to BAT. A transneuronal viral tract tracer, Bartha’s K strain of the pseudorabies virus (PRV), was injected into the interscapular BAT of Siberian hamsters. The animals were killed 4 and 6 days postinjection, and the infected neurons were visualized by immunocytochemistry. PRV-infected neurons were found in the spinal cord, brain stem, midbrain, and forebrain. The intensity of labeled neurons in the forebrain varied from heavy infections in the medial preoptic area and paraventricular hypothalamic nucleus to few infections in the ventromedial hypothalamic nucleus, with moderate infections in the suprachiasmatic and lateral hypothalamic nuclei. These results define the SNS outflow from the brain to BAT for the first time in any species.

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.

Regulation of brown adipose tissue lipogenesis by thyroid hormone and the sympathetic nervous system

1993 ◽  
Vol 265 (2) ◽  
pp. E252-E258 ◽  
Author(s):  
W. J. Yeh ◽  
P. Leahy ◽  
H. C. Freake
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Thyroid Hormone ◽  
Sympathetic Nervous System ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthase ◽  
Northern Analysis ◽  
Brown Adipose ◽  
Sympathetic Nervous

Thyroid hormone regulates lipogenesis differently in rat liver and brown adipose tissue (BAT). In the hypothyroid state, lipogenesis is suppressed in liver but enhanced in BAT. Here we investigated the mechanisms underlying increased lipogenesis in hypothyroid BAT. Housing the animals at 28 degrees C decreased lipogenesis in hypothyroid BAT to euthyroid levels. Denervation resulted in a 90% reduction in lipogenesis in hypothyroid BAT such that levels were lower than in euthyroid tissue. Thyroid hormone treatment of hypothyroid rats stimulated fatty acid synthesis in denervated BAT, as in liver, but decreased it in intact BAT. Steady-state levels of mRNA encoding acetyl-CoA carboxylase, fatty-acid synthase, and spor 14 were measured in similar animals by Northern analysis. The expression of these mRNAs mirrored the lipogenic data, showing that both thyroid hormone and the sympathetic nervous system work at a pretranslational level in this tissue. These data suggest that the increased BAT lipogenesis found with hypothyroidism is mediated by the sympathetic nervous system to counter the reduction in metabolic rate in these animals.

scholarly journals Chronic dietary supplementation of proanthocyanidins corrects the mitochondrial dysfunction of brown adipose tissue caused by diet-induced obesity in Wistar rats

2011 ◽  
Vol 107 (2) ◽  
pp. 170-178 ◽  
Author(s):  
David Pajuelo ◽  
Helena Quesada ◽  
Sabina Díaz ◽  
Anabel Fernández-Iglesias ◽  
Anna Arola-Arnal ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Citrate Synthase ◽  
Sirtuin 1 ◽  
Male Rats ◽  
Diet Induced Obesity ◽  
Brown Adipose

The present study aims to determine the effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) mitochondrial function in a state of obesity induced by diet. Wistar male rats were fed with a cafeteria diet (Cd) for 4 months; during the last 21 d, two groups were treated with doses of 25 and 50 mg GSPE/kg body weight. In the BAT, enzymatic activities of citrate synthase, cytochrome c oxidase (COX) and ATPase were determined and gene expression was analysed by real-time PCR. The mitochondrial function of BAT was determined in fresh mitochondria by high-resolution respirometry using both pyruvate and carnitine–palmitoyl-CoA as substrates. The results show that the Cd causes an important decrease in the gene expression of sirtuin 1, nuclear respiratory factor 1, isocitrate dehydrogenase 3γ and COX5α and, what is more telling, decreases the levels of mitochondrial respiration both with pyruvate and canitine–palmitoyl-CoA. Most of these parameters, which are indicative of mitochondrial dysfunction due to diet-induced obesity, are improved by chronic supplementation of GSPE. The beneficial effects caused by the administration of GSPE are exhibited as a protection against weight gain, in spite of the Cd the rats were fed. These data indicate that chronic consumption of a moderate dose of GSPE can correct an energy imbalance in a situation of diet-induced obesity, thereby improving the mitochondrial function and thermogenic capacity of the BAT.

Effects of ovariectomy and 17-β estradiol replacement on rat brown adipose tissue mitochondrial function

Steroids ◽  
2011 ◽  
Vol 76 (10-11) ◽  
pp. 1051-1056 ◽  
Author(s):  
Antònia Nadal-Casellas ◽  
Ana M. Proenza ◽  
Isabel Lladó ◽  
Magdalena Gianotti
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Function ◽  
Brown Adipose

scholarly journals Nicotine Improves Obesity and Hepatic Steatosis and ER Stress in Diet-Induced Obese Male Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (5) ◽  
pp. 1679-1689 ◽  
Author(s):  
Patricia Seoane-Collazo ◽  
Pablo B. Martínez de Morentin ◽  
Johan Fernø ◽  
Carlos Diéguez ◽  
Rubén Nogueiras ◽  
...  
Keyword(s):  
Nervous System ◽  
Body Weight ◽  
Adipose Tissue ◽  
Energy Balance ◽  
Protein Kinase ◽  
Brown Adipose Tissue ◽  
Male Rats ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Amp Activated Protein Kinase

Nicotine, the main addictive component of tobacco, promotes body weight reduction in humans and rodents. Recent evidence has suggested that nicotine acts in the central nervous system to modulate energy balance. Specifically, nicotine modulates hypothalamic AMP-activated protein kinase to decrease feeding and to increase brown adipose tissue thermogenesis through the sympathetic nervous system, leading to weight loss. Of note, most of this evidence has been obtained in animal models fed with normal diet or low-fat diet (LFD). However, its effectiveness in obese models remains elusive. Because obesity causes resistance towards many factors involved in energy homeostasis, the aim of this study has been to compare the effect of nicotine in a diet-induced obese (DIO) model, namely rats fed a high-fat diet, with rats fed a LFD. Our data show that chronic peripheral nicotine treatment reduced body weight by decreasing food intake and increasing brown adipose tissue thermogenesis in both LFD and DIO rats. This overall negative energy balance was associated to decreased activation of hypothalamic AMP-activated protein kinase in both models. Furthermore, nicotine improved serum lipid profile, decreased insulin serum levels, as well as reduced steatosis, inflammation, and endoplasmic reticulum stress in the liver of DIO rats but not in LFD rats. Overall, this evidence suggests that nicotine diminishes body weight and improves metabolic disorders linked to DIO and might offer a clear-cut strategy to develop new therapeutic approaches against obesity and its metabolic complications.

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