46 Inhibition of Lipolysis with Acipimox Targets Post-burn White Adipose Browning by Altering Macrophage Polarity

2020 ◽  
Vol 41 (Supplement_1) ◽  
pp. S30-S31
Author(s):  
Dalia Barayan ◽  
Roohi Vinaik ◽  
Marc G Jeschke
Keyword(s):  
Adipose Tissue ◽  
Uncoupling Protein ◽  
Polarization State ◽  
Critical Role ◽  
Metabolic Effects ◽  
Inhibitory Effects ◽  
Macrophage Recruitment ◽  
M2 Polarization ◽  
Brown Adipose ◽  
Major Burn

Abstract Introduction Severe burns are accompanied by a detrimental hypermetabolic stress response that can persist for years post-injury. Our previous work revealed that, under prolonged stress, white adipose tissue (WAT) adopts brown adipose-like traits in a process termed ‘browning’. This switch, characterized by the presence of uncoupling protein 1 (UCP1), is driven by the polarization of macrophages towards an M2 phenotype. Recently, we demonstrated that inhibiting lipolysis with the clinically approved drug, Acipimox, represses the burn-induced thermogenic activation of WAT. These findings raise the possibility that elevated rates of lipolysis may play a role in regulating the macrophage polarization state after major burn. However, the interconnection between post-burn lipolysis and inflammation remains unclear. In the present study, we investigated the mechanism underlying Acipimox’s inhibitory effects on burn-induced browning. Using a mouse model of thermal injury, we determine the metabolic effects of reducing WAT lipolysis on burn-induced macrophage recruitment and M2-polarization. Methods Adult C57BL/6 mice received a 30% total body surface area scald burn. Mice were then given daily intraperitoneal injections of APX (50 mg/Kg). On day 7 post-burn, the inguinal adipose tissue depot (iWAT) was harvested for histological analyses. Flow cytometry and F4/80 staining were used to assess adipose macrophage distribution and profile, and gene expression was analyzed via qPCR. Results APX administration significantly increased mitochondrial coupling, reflected by the decrease in UCP-1 (p< 0.05) and PGC-1a (p< 0.01) levels relative to the iWAT of untreated burn mice. F4/80 immunostaining of iWAT demonstrated decreased macrophage recruitment in Acipimox treated mice (p< 0.05). Flow cytometric analysis indicated decreased macrophage infiltration at 7 days in Acipimox treated mice (p< 0.05). Furthermore, iWAT from Acipimox treated mice demonstrated a pro-inflammatory profile, indicated by a greater distribution of TLR4 positive macrophages (p< 0.05). Conclusions Previously, we showed that the administration of Acipimox effectively suppressed PKA-mediated lipolysis and improved mitochondrial coupling in adipose tissue post-burn. Here, we elucidate the mechanism underlying these metabolic changes. Importantly, we show Acipimox exerts its inhibitory effects on burn-induced WAT browning by directly modulating macrophage recruitment and the M2-polarization state. Applicability of Research to Practice Our study highlights the critical role of lipolysis in mediating the key post-burn metabolic phenomena browning and inflammation. The data presented herein validate the pharmacological inhibition of lipolysis as a potentially powerful therapeutic strategy to counteract the detrimental metabolic effects induced by burn.

scholarly journals Metabolic Effects of Oral Phenelzine Treatment on High-Sucrose-Drinking Mice

2018 ◽  
Vol 19 (10) ◽  
pp. 2904 ◽  
Author(s):  
Christian Carpéné ◽  
Saioa Gómez-Zorita ◽  
Alice Chaplin ◽  
Josep Mercader
Keyword(s):  
Adipose Tissue ◽  
Phosphoenolpyruvate Carboxykinase ◽  
De Novo ◽  
Uncoupling Protein ◽  
De Novo Lipogenesis ◽  
Metabolic Effects ◽  
Mrna Levels ◽  
Brown Adipose ◽  
High Sucrose ◽  
Sucrose Drinking

Phenelzine has been suggested to have an antiobesity effect by inhibiting de novo lipogenesis, which led us to investigate the metabolic effects of oral chronic phenelzine treatment in high-sucrose-drinking mice. Sucrose-drinking mice presented higher body weight gain and adiposity versus controls. Phenelzine addition did not decrease such parameters, even though fat pad lipid content and weights were not different from controls. In visceral adipocytes, phenelzine did not impair insulin-stimulated de novo lipogenesis and had no effect on lipolysis. However, phenelzine reduced the mRNA levels of glucose transporters 1 and 4 and phosphoenolpyruvate carboxykinase in inguinal white adipose tissue (iWAT), and altered circulating levels of free fatty acids (FFA) and glycerol. Interestingly, glycemia was restored in phenelzine-treated mice, which also had higher insulinaemia. Phenelzine-treated mice presented higher rectal temperature, which was associated to reduced mRNA levels of uncoupling protein 1 in brown adipose tissue. Furthermore, unlike sucrose-drinking mice, hepatic malondialdehyde levels were not altered. In conclusion, although de novo lipogenesis was not inhibited by phenelzine, the data suggest that the ability to re-esterify FFA is impaired in iWAT. Moreover, the effects on glucose homeostasis and oxidative stress suggest that phenelzine could alleviate obesity-related alterations and deserves further investigation in obesity models.

scholarly journals ChREBP-β regulates thermogenesis in brown adipose tissue

2020 ◽  
Vol 245 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Chunchun Wei ◽  
Xianhua Ma ◽  
Kai Su ◽  
Shasha Qi ◽  
Yuangang Zhu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Uncoupling Protein ◽  
Critical Role ◽  
Active Form ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Brown Adipose ◽  
Metabolic Remodeling

Brown adipose tissue (BAT) plays a critical role in energy expenditure by uncoupling protein 1 (UCP1)-mediated thermogenesis. Carbohydrate response element-binding protein (ChREBP) is one of the key transcription factors regulating de novo lipogenesis (DNL). As a constitutively active form, ChREBP-β is expressed at extremely low levels. Up to date, its functional relevance in BAT remains unclear. In this study, we show that ChREBP-β inhibits BAT thermogenesis. BAT ChREBP-β mRNA levels were elevated upon cold exposure, which prompted us to generate a mouse model overexpressing ChREBP-β specifically in BAT using the Cre/LoxP approach. ChREBP-β overexpression led to a whitening phenotype of BAT at room temperature, as evidenced by increased lipid droplet size and decreased mitochondrion content. Moreover, BAT thermogenesis was inhibited upon acute cold exposure, and its metabolic remodeling induced by long-term cold adaptation was significantly impaired by ChREBP-β overexpression. Mechanistically, ChREBP-β overexpression downregulated expression of genes involved in mitochondrial biogenesis, autophagy, and respiration. Furthermore, thermogenic gene expression (e.g. Dio2, UCP1) was markedly inhibited in BAT by the overexpressed ChREBP-β. Put together, our work points to ChREBP-β as a negative regulator of thermogenesis in brown adipocytes.

scholarly journals Orally Induced Hyperthyroidism Regulates Hypothalamic AMP-Activated Protein Kinase

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4204
Author(s):  
Valentina Capelli ◽  
Carmen Grijota-Martínez ◽  
Nathalia R. V. Dragano ◽  
Eval Rial-Pensado ◽  
Johan Fernø ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Protein Kinase ◽  
Energy Homeostasis ◽  
Uncoupling Protein ◽  
Core Body Temperature ◽  
Metabolic Effects ◽  
Central Administration ◽  
Treatment Protocols ◽  
Brown Adipose ◽  
Amp Activated Protein Kinase

Besides their direct effects on peripheral metabolic tissues, thyroid hormones (TH) act on the hypothalamus to modulate energy homeostasis. However, since most of the hypothalamic actions of TH have been addressed in studies with direct central administration, the estimation of the relative contribution of the central vs. peripheral effects in physiologic conditions of peripheral release (or administration) of TH remains unclear. In this study we used two different models of peripherally induced hyperthyroidism (i.e., T4 and T3 oral administration) to assess and compare the serum and hypothalamic TH status and relate them to the metabolic effects of the treatment. Peripheral TH treatment affected feeding behavior, overall growth, core body temperature, body composition, brown adipose tissue (BAT) morphology and uncoupling protein 1 (UCP1) levels and metabolic activity, white adipose tissue (WAT) browning and liver metabolism. This resulted in an increased overall uncoupling capacity and a shift of the lipid metabolism from WAT accumulation to BAT fueling. Both peripheral treatment protocols induced significant changes in TH concentrations within the hypothalamus, with T3 eliciting a downregulation of hypothalamic AMP-activated protein kinase (AMPK), supporting the existence of a central action of peripheral TH. Altogether, these data suggest that peripherally administered TH modulate energy balance by various mechanisms; they also provide a unifying vision of the centrally mediated and the direct local metabolic effect of TH in the context of hyperthyroidism.

scholarly journals MCP-1 deficiency enhances browning of adipose tissue via increased M2 polarization

2019 ◽  
Vol 242 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Monisha Rajasekaran ◽  
Ok-Joo Sul ◽  
Eun-Kyung Choi ◽  
Ji-Eun Kim ◽  
Jae-Hee Suh ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Nuclear Translocation ◽  
Macrophage Polarization ◽  
Critical Role ◽  
M2 Macrophage ◽  
M2 Polarization ◽  
Mitochondrial Dna Copy Number ◽  
M1 Polarization ◽  
Brown Adipose

Obesity is strongly associated with chronic inflammation for which adipose tissue macrophages play a critical role. The objective of this study is to identify monocyte chemoattractant protein-1 (MCP-1, CCL2) as a key player governing M1–M2 macrophage polarization and energy balance. We evaluated body weight, fat mass, adipocyte size and energy expenditure as well as core body temperature of Ccl2 knockout mice compared with wild-type mice. Adipose tissues, differentiated adipocyte and bone marrow-derived macrophages were assessed by qPCR, Western blot analysis and histochemistry. MCP-1 deficiency augmented energy expenditure by promoting browning in white adipose tissue and brown adipose tissue activity via increasing the expressions of Ucp1, Prdm16, Tnfrsf9, Ppargc1a, Nrf1 and Th and mitochondrial DNA copy number. MCP-1 abrogation promoted M2 polarization which is characterized by increased expression of Arg1, Chil3, Il10 and Klf4 whereas it decreased M1 polarization by decreased p65 nuclear translocation and attenuated expression of Itgax, Tnf and Nos2, leading to increased browning of adipocytes. Enhanced M2 polarization and attenuated M1 polarization in the absence of MCP-1 are independent. Collectively, our results suggest that the action of MCP-1 in macrophages modulates energy expenditure by impairing browning in adipose tissue.

scholarly journals Role of the Central Melanocortin Circuitry in Adaptive Thermogenesis of Brown Adipose Tissue

Endocrinology ◽  
2007 ◽  
Vol 148 (4) ◽  
pp. 1550-1560 ◽  
Author(s):  
Adriana Voss-Andreae ◽  
Jonathan G. Murphy ◽  
Kate L. J. Ellacott ◽  
Ronald C. Stuart ◽  
Eduardo A. Nillni ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Energy Homeostasis ◽  
Pseudorabies Virus ◽  
Uncoupling Protein ◽  
Critical Role ◽  
Uncoupling Protein 1 ◽  
Adaptive Thermogenesis ◽  
Melanocortin 4 Receptor ◽  
Brown Adipose

The central melanocortin 4 receptor (MC4R) plays a critical role in energy homeostasis, although little is known regarding its role in the regulation of adaptive thermogenesis of brown adipose tissue (BAT). Here we show using retrograde transsynaptic tracing with attenuated pseudorabies virus coupled with dual-label immunohistochemistry that specific subsets of MC4R-expressing neurons in multiple nuclei of the central nervous system known to regulate sympathetic outflow polysynaptically connect with interscapular BAT (IBAT). Furthermore, we show that MC4R−/− and agouti-related peptide-treated mice are defective in HF diet-induced up-regulation of uncoupling protein 1 in IBAT. Additionally, MC4R−/− mice exposed to 4 C for 4 h exhibit a defect in up-regulation of uncoupling protein 1 levels in IBAT. Our results provide a neuroanatomic substrate for MC4R regulating sympathetically mediated IBAT thermogenesis and demonstrate that the MC4R is critically required for acute high-fat- and cold-induced IBAT thermogenesis.

Characterization of MCH-mediated obesity in mice

2003 ◽  
Vol 284 (5) ◽  
pp. E940-E945 ◽  
Author(s):  
Masahiko Ito ◽  
Akira Gomori ◽  
Akane Ishihara ◽  
Zenjun Oda ◽  
Satoshi Mashiko ◽  
...  
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Body Weight Gain ◽  
Uncoupling Protein ◽  
Critical Role ◽  
Acid Oxidation ◽  
Intracerebroventricular Infusion ◽  
Brown Adipose ◽  
Ad Libitum ◽  
Lipogenic Activity

Melanin-concentrating hormone (MCH) is a cyclic orexigenic peptide expressed in the lateral hypothalamus. Recently, we demonstrated that chronic intracerebroventricular infusion of MCH induced obesity accompanied by sustained hyperphagia in mice. Here, we analyzed the mechanism of MCH-induced obesity by comparing animals fed ad libitum with pair-fed and control animals. Chronic infusion of MCH significantly increased food intake, body weight, white adipose tissue (WAT) mass, and liver mass in ad libitum-fed mice on a moderately high-fat diet. In addition, a significant increase in lipogenic activity was observed in the WAT of the ad libitum-fed group. Although body weight gain was marginal in the pair-fed group, MCH infusion clearly enhanced the lipogenic activity in liver and WAT. Plasma leptin levels were also increased in the pair-fed group. Furthermore, MCH infusion significantly reduced rectal temperatures in the pair-fed group. In support of these findings, mRNA expression of uncoupling protein-1, acyl-CoA oxidase, and carnitine palmitoyltransferase I, which are key molecules involved in thermogenesis and fatty acid oxidation, were reduced in the brown adipose tissue (BAT) of the pair-fed group, suggesting that MCH infusion might reduce BAT functions. We conclude that the activation of MCH neuronal pathways stimulated adiposity, in part resulting from increased lipogenesis in liver and WAT and reduced energy expenditure in BAT. These findings confirm that modulation of energy homeostasis by MCH may play a critical role in the development of obesity.

scholarly journals Adipose tissue insulin resistance due to loss of PI3K p110α leads to decreased energy expenditure and obesity

2014 ◽  
Vol 306 (10) ◽  
pp. E1205-E1216 ◽  
Author(s):  
Victoria L. B. Nelson ◽  
Ya-Ping Jiang ◽  
Kathleen G. Dickman ◽  
Lisa M. Ballou ◽  
Richard Z. Lin
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Insulin Signaling ◽  
Uncoupling Protein ◽  
Critical Role ◽  
Liver Steatosis ◽  
Cellular Respiration ◽  
Brown Adipose

Adipose tissue is a highly insulin-responsive organ that contributes to metabolic regulation. Insulin resistance in the adipose tissue affects systemic lipid and glucose homeostasis. Phosphoinositide 3-kinase (PI3K) mediates downstream insulin signaling in adipose tissue, but its physiological role in vivo remains unclear. Using Cre recombinase driven by the aP2 promoter, we created mice that lack the class 1A PI3K catalytic subunit p110α or p110β specifically in the white and brown adipose tissue. The loss of p110α, not p110β, resulted in increased adiposity, glucose intolerance and liver steatosis. Mice lacking p110α in adipose tissue exhibited a decrease in energy expenditure but no change in food intake or activity compared with control animals. This low energy expenditure is a consequence of low cellular respiration in the brown adipocytes caused by a decrease in expression of key mitochondrial genes including uncoupling protein-1. These results illustrate a critical role of p110α in the regulation of energy expenditure through modulation of cellular respiration in the brown adipose tissue and suggest that compromised insulin signaling in adipose tissue might be involved in the onset of obesity.

scholarly journals A single mutation in uncoupling protein of rat brown adipose tissue mitochondria abolishes GDP sensitivity of H+ transport.

1994 ◽  
Vol 269 (10) ◽  
pp. 7435-7438
Author(s):  
D.L. Murdza-Inglis ◽  
M. Modriansky ◽  
H.V. Patel ◽  
G. Woldegiorgis ◽  
K.B. Freeman ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Single Mutation ◽  
Brown Adipose

scholarly journals Eicosapentaenoic Acid Increases Browning Markers in Subcutaneous Adipose Tissue and Primary Adipocytes from Wild Type and UCP-1 Deficient Mice (P15-007-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Shasika Jayarathne ◽  
Mandana Pahlavani ◽  
Latha Ramalingam ◽  
Shane Scoggin ◽  
Naima Moustaid-Moussa
Keyword(s):  
Adipose Tissue ◽  
Eicosapentaenoic Acid ◽  
Subcutaneous Adipose Tissue ◽  
Uncoupling Protein ◽  
Fibroblast Growth Factor 21 ◽  
Chow Diet ◽  
Mrna Levels ◽  
Wild Type ◽  
Brown Adipose ◽  
Subcutaneous Adipose

Abstract Objectives Brown adipose tissue (BAT) regulates energy balance through thermogenesis, in part via uncoupling protein -1 (UCP-1). White adipose tissue (WAT), namely subcutaneous adipose tissue (SAT) can convert to a beige/brite adipose tissue phenotype (browning) under thermogenic conditions such as cold. We previously reported that eicosapentaenoic acid (EPA) reduced obesity and glucose intolerance, and increased UCP-1 in BAT of B6 mice at ambient temperature (22°C); and these effects were attenuated at thermoneutral environment (28–30°C). We hypothesized that EPA exerts anti-obesity effects on SAT, including increased browning, adipocyte hypotrophy; and these effects require UCP-1. Methods Six-week-old B6 wild type (WT) and UCP-1 knock-out (KO) male mice were maintained at thermoneutral environment and fed high fat diet (HF) with or without 36 g/kg of AlaskOmega EPA-enriched fish oil (800 mg/g) for 14 weeks; and SAT was collected for histological, gene and protein analyses. SAT was also prepared from chow diet-fed WT and KO mice at ambient environment to prepare stroma vascular cells, which were differentiated into adipocytes, treated with 100uM EPA for 48 hours then harvested for mRNA and protein analyses. Results KO mice fed HF diets had the highest body weight (P < 0.05) among all groups. EPA reduced fat cell size in both WT and KO mice fed the EPA diet. mRNA levels of fibroblast growth factor-21 (FGF-21) were higher in SAT of WT mice fed EPA compared to WT mice fed HF (P < 0.05), with no differences between the KO genotype. KO mice fed HF diets had lower levels of UCP-3 in SAT compared to WT mice fed HF (P < 0.05), which was rescued only in the KO mice fed EPA (P < 0.05). UCP-1 protein levels were very low in SAT tissues, and UCP-2 mRNA levels were similar across all groups in SAT. Interestingly, EPA significantly (P < 0.05) increased mRNA expression of UCP-2, UCP-3 and FGF21 in differentiated SAT adipocytes from both WT and KO compared to control. Furthermore, UCP-1 mRNA levels were significantly higher in WT adipocytes treated with EPA, compared to non-treated cells (P < 0.05). Additional mechanistic studies are currently underway to further dissect adipose depot differences in EPA effects in WT vs. KO mice. Conclusions Our data suggest that EPA increases SAT browning, independently of UCP-1. Funding Sources NIH/NCCIH.

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