scholarly journals Identification and characterization of distinct murine brown adipocyte lineages

2020 ◽  
Author(s):  
Ruth Karlina ◽  
Dominik Lutter ◽  
Viktorian Miok ◽  
David Fischer ◽  
Irem Altun ◽  
...  

AbstractBrown adipose tissue (BAT) plays an important role in the regulation of body weight and glucose homeostasis. While increasing evidence supports white adipose tissue heterogeneity, little is known about heterogeneity within murine BAT. Using single cell RNA sequencing of the stromal vascular fraction of murine BAT and analysis of 67 brown preadipocyte and adipocyte clones we unravel heterogeneity within brown preadipocytes. Statistical analysis of gene expression profiles from these clones identifies markers distinguishing brown adipocyte lineages. We confirm the presence of distinct brown adipocyte populations in vivo using three identified markers; Eif5, Tcf25, and Bin1. Functionally, we demonstrate that loss of Bin1 enhances UCP1 expression and mitochondrial respiration, suggesting that Bin1 marks a dormant brown adipocyte type. The existence of multiple brown adipocyte lineages suggests distinct functional properties of BAT depending on its cellular composition, with potentially distinct function in thermogenesis and the regulation of whole body energy homeostasis.

2020 ◽  
Vol 4 (1) ◽  
pp. e202000924
Author(s):  
Ruth Karlina ◽  
Dominik Lutter ◽  
Viktorian Miok ◽  
David Fischer ◽  
Irem Altun ◽  
...  

Brown adipose tissue (BAT) plays an important role in the regulation of body weight and glucose homeostasis. Although increasing evidence supports white adipose tissue heterogeneity, little is known about heterogeneity within murine BAT. Recently, UCP1 high and low expressing brown adipocytes were identified, but a developmental origin of these subtypes has not been studied. To obtain more insights into brown preadipocyte heterogeneity, we use single-cell RNA sequencing of the BAT stromal vascular fraction of C57/BL6 mice and characterize brown preadipocyte and adipocyte clonal cell lines. Statistical analysis of gene expression profiles from brown preadipocyte and adipocyte clones identify markers distinguishing brown adipocyte subtypes. We confirm the presence of distinct brown adipocyte populations in vivo using the markers EIF5, TCF25, and BIN1. We also demonstrate that loss of Bin1 enhances UCP1 expression and mitochondrial respiration, suggesting that BIN1 marks dormant brown adipocytes. The existence of multiple brown adipocyte subtypes suggests distinct functional properties of BAT depending on its cellular composition, with potentially distinct functions in thermogenesis and the regulation of whole body energy homeostasis.


2019 ◽  
Vol 116 (47) ◽  
pp. 23822-23828 ◽  
Author(s):  
Shintaro Yamaguchi ◽  
Michael P. Franczyk ◽  
Maria Chondronikola ◽  
Nathan Qi ◽  
Subhadra C. Gunawardana ◽  
...  

Nicotinamide adenine dinucleotide (NAD+) is a critical coenzyme for cellular energy metabolism. The aim of the present study was to determine the importance of brown and white adipose tissue (BAT and WAT) NAD+ metabolism in regulating whole-body thermogenesis and energy metabolism. Accordingly, we generated and analyzed adipocyte-specific nicotinamide phosphoribosyltransferase (Nampt) knockout (ANKO) and brown adipocyte-specific Nampt knockout (BANKO) mice because NAMPT is the rate-limiting NAD+ biosynthetic enzyme. We found ANKO mice, which lack NAMPT in both BAT and WAT, had impaired gene programs involved in thermogenesis and mitochondrial function in BAT and a blunted thermogenic (rectal temperature, BAT temperature, and whole-body oxygen consumption) response to acute cold exposure, prolonged fasting, and administration of β-adrenergic agonists (norepinephrine and CL-316243). In addition, the absence of NAMPT in WAT markedly reduced adrenergic-mediated lipolytic activity, likely through inactivation of the NAD+–SIRT1–caveolin-1 axis, which limits an important fuel source fatty acid for BAT thermogenesis. These metabolic abnormalities were rescued by treatment with nicotinamide mononucleotide (NMN), which bypasses the block in NAD+ synthesis induced by NAMPT deficiency. Although BANKO mice, which lack NAMPT in BAT only, had BAT cellular alterations similar to the ANKO mice, BANKO mice had normal thermogenic and lipolytic responses. We also found NAMPT expression in supraclavicular adipose tissue (where human BAT is localized) obtained from human subjects increased during cold exposure, suggesting our finding in rodents could apply to people. These results demonstrate that adipose NAMPT-mediated NAD+ biosynthesis is essential for regulating adaptive thermogenesis, lipolysis, and whole-body energy metabolism.


Endocrinology ◽  
2011 ◽  
Vol 152 (10) ◽  
pp. 3628-3637 ◽  
Author(s):  
R. Gonzalez ◽  
R. L. S. Perry ◽  
X. Gao ◽  
M. P. Gaidhu ◽  
R. G. Tsushima ◽  
...  

Nesfatin-1 is a recently discovered anorexigen, and we first reported nesfatin-like immunoreactivity in the pancreatic β-cells. The aim of this study was to characterize the effects of nesfatin-1 on whole-body energy homeostasis, insulin secretion, and glycemia. The in vivo effects of continuous peripheral delivery of nesfatin-1 using osmotic minipumps on food intake and substrate partitioning were examined in ad libitum-fed male Fischer 344 rats. The effects of nesfatin-1 on glucose-stimulated insulin secretion (GSIS) were examined in isolated pancreatic islets. L6 skeletal muscle cells and isolated rat adipocytes were used to assess the effects of nesfatin-1 on basal and insulin-mediated glucose uptake as well as on major steps of insulin signaling in these cells. Nesfatin-1 reduced cumulative food intake and increased spontaneous physical activity, whole-body fat oxidation, and carnitine palmitoyltransferase I mRNA expression in brown adipose tissue but did not affect uncoupling protein 1 mRNA in the brown adipose tissue. Nesfatin-1 significantly enhanced GSIS in vivo during an oral glucose tolerance test and improved insulin sensitivity. Although insulin-stimulated glucose uptake in L6 muscle cells was inhibited by nesfatin-1 pretreatment, basal and insulin-induced glucose uptake in adipocytes from nesfatin-1-treated rats was significantly increased. In agreement with our in vivo results, nesfatin-1 enhanced GSIS from isolated pancreatic islets at both normal (5.6 mm) and high (16.7 mm), but not at low (2 mm), glucose concentrations. Furthermore, nesfatin-1/nucleobindin 2 release from rat pancreatic islets was stimulated by glucose. Collectively, our data indicate that glucose-responsive nesfatin-1 regulates insulin secretion, glucose homeostasis, and whole-body energy balance in rats.


Endocrinology ◽  
2013 ◽  
Vol 154 (9) ◽  
pp. 3152-3167 ◽  
Author(s):  
Emilia Guirguis ◽  
Steven Hockman ◽  
Youn Wook Chung ◽  
Faiyaz Ahmad ◽  
Oksana Gavrilova ◽  
...  

Obesity is linked to various diseases, including insulin resistance, diabetes, and cardiovascular disorders. The idea of inducing white adipose tissue (WAT) to assume characteristics of brown adipose tissue (BAT), and thus gearing it to fat burning instead of storage, is receiving serious consideration as potential treatment for obesity and related disorders. Phosphodiesterase 3B (PDE3B) links insulin- and cAMP-signaling networks in tissues associated with energy metabolism, including WAT. We used C57BL/6 PDE3B knockout (KO) mice to elucidate mechanisms involved in the formation of BAT in epididymal WAT (EWAT) depots. Examination of gene expression profiles in PDE3B KO EWAT revealed increased expression of several genes that block white and promote brown adipogenesis, such as C-terminal binding protein, bone morphogenetic protein 7, and PR domain containing 16, but a clear BAT-like phenotype was not completely induced. However, acute treatment of PDE3B KO mice with the β3-adrenergic agonist, CL316243, markedly increased the expression of cyclooxygenase-2, which catalyzes prostaglandin synthesis and is thought to be important in the formation of BAT in WAT and the elongation of very long-chain fatty acids 3, which is linked to BAT recruitment upon cold exposure, causing a clear shift toward fat burning and the induction of BAT in KO EWAT. These data provide insight into the mechanisms of BAT formation in mouse EWAT, suggesting that, in a C57BL/6 background, an increase in cAMP, caused by ablation of PDE3B and administration of CL316243, may promote differentiation of prostaglandin-responsive progenitor cells in the EWAT stromal vascular fraction into functional brown adipocytes.


Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Fenfen Li ◽  
Shirong Wang ◽  
Xin Cui ◽  
Jia Jing ◽  
Liqing Yu ◽  
...  

While the main function of white adipose tissue (WAT) is to store surplus of energy as triacylglycerol, that of brown adipose tissue (BAT) is to burn energy as heat. Epigenetic mechanisms participate prominently in both WAT and BAT energy metabolism. We previously reported that the histone demethylase ubiquitously transcribed tetratricopeptide (Utx) is a positive regulator of brown adipocyte thermogenesis. Here, we aimed to investigate whether Utx also regulates WAT metabolism in vivo. We generated a mouse model with Utx deficiency in adipocytes (AUTXKO). AUTXKO animals fed a chow diet had higher body weight, more fat mass and impaired glucose tolerance. AUTXKO mice also exhibited cold intolerance with an impaired brown fat thermogenic program. When challenged with high-fat diet (HFD), AUTXKO mice displayed adipose dysfunction featured by suppressed lipogenic pathways, exacerbated inflammation and fibrosis with less fat storage in adipose tissues and more lipid storage in the liver; as a result, AUTXKO mice showed a disturbance in whole body glucose homeostasis and hepatic steatosis. Our data demonstrate that Utx deficiency in adipocytes limits adipose tissue expansion under HFD challenge and induces metabolic dysfunction via adipose tissue remodeling. We conclude that adipocyte Utx is a key regulator of systemic metabolic homeostasis.


2020 ◽  
Vol 40 (1) ◽  
pp. 25-49 ◽  
Author(s):  
Nishan Sudheera Kalupahana ◽  
Bimba Lakmini Goonapienuwala ◽  
Naima Moustaid-Moussa

White adipose tissue (WAT) and brown adipose tissue (BAT) are involved in whole-body energy homeostasis and metabolic regulation. Changes to mass and function of these tissues impact glucose homeostasis and whole-body energy balance during development of obesity, weight loss, and subsequent weight regain. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), which have known hypotriglyceridemic and cardioprotective effects, can also impact WAT and BAT function. In rodent models, these fatty acids alleviate obesity-associated WAT inflammation, improve energy metabolism, and increase thermogenic markers in BAT. Emerging evidence suggests that ω-3 PUFAs can also modulate gut microbiota impacting WAT function and adiposity. This review discusses molecular mechanisms, implications of these findings, translation to humans, and future work, especially with reference to the potential of these fatty acids in weight loss maintenance.


2009 ◽  
Vol 20 (3) ◽  
pp. 801-808 ◽  
Author(s):  
Fei Wang ◽  
Qiang Tong

Sirtuin family of proteins possesses NAD-dependent deacetylase and ADP ribosyltransferase activities. They are found to respond to nutrient deprivation and profoundly regulate metabolic functions. We have previously reported that caloric restriction increases the expression of one of the seven mammalian sirtuins, SIRT2, in tissues such as white adipose tissue. Because adipose tissue is a key metabolic organ playing a critical role in whole body energy homeostasis, we went on to explore the function of SIRT2 in adipose tissue. We found short-term food deprivation for 24 h, already induces SIRT2 expression in white and brown adipose tissues. Additionally, cold exposure elevates SIRT2 expression in brown adipose tissue but not in white adipose tissue. Intraperitoneal injection of a β-adrenergic agonist (isoproterenol) enhances SIRT2 expression in white adipose tissue. Retroviral expression of SIRT2 in 3T3-L1 adipocytes promotes lipolysis. SIRT2 inhibits 3T3-L1 adipocyte differentiation in low-glucose (1 g/l) or low-insulin (100 nM) condition. Mechanistically, SIRT2 suppresses adipogenesis by deacetylating FOXO1 to promote FOXO1's binding to PPARγ and subsequent repression on PPARγ transcriptional activity. Overall, our results indicate that SIRT2 responds to nutrient deprivation and energy expenditure to maintain energy homeostasis by promoting lipolysis and inhibiting adipocyte differentiation.


2019 ◽  
Author(s):  
Chuanhai Zhang ◽  
Xiaoyun He ◽  
Yao Sheng ◽  
Jia Xu ◽  
Cui Yang ◽  
...  

AbstractBackground/objectives:Disorder of energy homeostasis can lead to a variety of metabolic diseases, especially obesity. Brown adipose tissue (BAT) is a promising potential therapeutic target for the treatment of obesity and related metabolic diseases. Allicin, a main bioactive ingredient in garlic, has multiple biology and pharmacological function. However, the role of Allicin, in the regulation of metabolic organ, especially the role of activation of BAT, has not been well studied. Here, we analyzed the role of Allicin in whole-body metabolism and the activation of BAT.Results:Allicin had a significant effect in inhibiting body weight gain, decreasing adiposity, maintaining glucose homeostasis, improving insulin resistance, and ameliorating hepatic steatosis in diet-introduced obesity (DIO) mice. Then we find that Allicin can strongly activate brown adipose tissue (BAT). The activation of brown adipocyte treated with Allicin was also confirmed in mouse primary brown adipocytes.Conclusion:Allicin can ameliorate obesity through activating brown adipose tissue. Our findings provide a promising therapeutic approach for the treatment of obesity and metabolic disorders.


2016 ◽  
Vol 48 (6) ◽  
pp. 420-427 ◽  
Author(s):  
Michal Pravenec ◽  
Petr Mlejnek ◽  
Václav Zídek ◽  
Vladimír Landa ◽  
Miroslava Šimáková ◽  
...  

Resistin has been originally identified as an adipokine that links obesity to insulin resistance in mice. In our previous studies in spontaneously hypertensive rats (SHR) expressing a nonsecreted form of mouse resistin ( Retn) transgene specifically in adipose tissue (SHR- Retn), we have observed an increased lipolysis and serum free fatty acids, ectopic fat accumulation in muscles, and insulin resistance. Recently, brown adipose tissue (BAT) has been suggested to play an important role in the pathogenesis of metabolic disturbances. In the current study, we have analyzed autocrine effects of transgenic resistin on BAT glucose and lipid metabolism and mitochondrial function in the SHR- Retn vs. nontransgenic SHR controls. We observed that interscapular BAT isolated from SHR- Retn transgenic rats compared with SHR controls showed a lower relative weight (0.71 ± 0.05 vs. 0.91 ± 0.08 g/100 g body wt, P < 0.05), significantly reduced both basal and insulin stimulated incorporation of palmitate into BAT lipids (658 ± 50 vs. 856 ± 45 and 864 ± 47 vs. 1,086 ± 35 nmol/g/2 h, P ≤ 0.01, respectively), and significantly decreased palmitate oxidation (37.6 ± 4.5 vs. 57 ± 4.1 nmol/g/2 h, P = 0.007) and glucose oxidation (277 ± 34 vs. 458 ± 38 nmol/g/2 h, P = 0.001). In addition, in vivo microPET imaging revealed significantly reduced 18F-FDG uptake in BAT induced by exposure to cold in SHR- Retn vs. control SHR (232 ± 19 vs. 334 ± 22 kBq/ml, P < 0.05). Gene expression profiles in BAT identified differentially expressed genes involved in skeletal muscle and connective tissue development, inflammation and MAPK and insulin signaling. These results provide evidence that autocrine effects of resistin attenuate differentiation and activity of BAT and thus may play a role in the pathogenesis of insulin resistance in the rat.


2021 ◽  
Author(s):  
Zyanya Díaz-Hirashi ◽  
Tian Gao ◽  
Chiara Scaffidi ◽  
Monika Fey ◽  
Susan Murray ◽  
...  

Abstract Whole-body energy homeostasis is influenced by anabolic and catabolic cellular programs, which depend on environmental and nutritional cues. Adipose tissue plays a predominant role in the physiological regulation of energy balance by either storing or consuming energy through brown adipose tissue thermogenesis. It is however not clearly understood how brown adipose tissue balances catabolic and anabolic states. We show here that the transcription factor YY1 senses energetic state through a post-translational S120 phosphorylation switch. Adrenergic signaling leads to YY1 dephosphorylation which directly activates thermogenesis and a catabolic gene program while its phosphorylation maintains an anabolic program. Mechanistically, YY1 dephosphorylation increases chromatin binding at distal genomic loci respective to the transcription start site but remains constitutively bound to TSS. This mode of transcriptional control influences the activating and repressive function of YY1 and regulates catabolism/anabolism. We show that YY1 interacts with PPP1R3B, a regulatory subunit of the phosphatase PP1 and that in vivo knockdown of PPP1R3B protects against diet-induced obesity and insulin resistance. Our results uncover a novel transcriptional mechanism of metabolism orchestrated by YY1 phosphorylation switch and identifies PPP1R3B as a regulator of energy balance.


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