scholarly journals Regulatory circuits controlling white versus brown adipocyte differentiation

2006 ◽  
Vol 398 (2) ◽  
pp. 153-168 ◽  
Author(s):  
Jacob B. Hansen ◽  
Karsten Kristiansen

Adipose tissue is a major endocrine organ that exerts a profound influence on whole-body homoeostasis. Two types of adipose tissue exist in mammals: WAT (white adipose tissue) and BAT (brown adipose tissue). WAT stores energy and is the largest energy reserve in mammals, whereas BAT, expressing UCP1 (uncoupling protein 1), can dissipate energy through adaptive thermogenesis. In rodents, ample evidence supports BAT as an organ counteracting obesity, whereas less is known about the presence and significance of BAT in humans. Despite the different functions of white and brown adipocytes, knowledge of factors differentially influencing the formation of white and brown fat cells is sparse. Here we summarize recent progress in the molecular understanding of white versus brown adipocyte differentiation, including novel insights into transcriptional and signal transduction pathways. Since expression of UCP1 is the hallmark of BAT and a key factor determining energy expenditure, we also review conditions associated with enhanced energy expenditure and UCP1 expression in WAT that may provide information on processes involved in brown adipocyte differentiation.

2021 ◽  
Author(s):  
Mingsheng Ye ◽  
Liping Luo ◽  
Qi Guo ◽  
Guanghua Lei ◽  
Chao Zeng ◽  
...  

Brown adipose tissue (BAT) is emerging as a target to beat obesity through the dissipation of chemical energy to heat. However, the molecular mechanisms of brown adipocyte thermogenesis remain to be further elucidated. Here, we show that KCTD10, a member of the polymerase delta-interacting protein 1 (PDIP1) family, was reduced in BAT by cold stress and a β3 adrenoceptor agonist. Moreover, KCTD10 level increased in the BAT of obese mice, and KCTD10 overexpression attenuates uncoupling protein 1 (UCP1) expression in primary brown adipocytes. BAT-specific KCTD10 knockdown mice had increased thermogenesis and cold tolerance protecting from high fat diet (HFD)-induced obesity. Conversely, overexpression of KCTD10 in BAT caused reduced thermogenesis, cold intolerance, and obesity. Mechanistically, inhibiting Notch signaling restored the KCTD10 overexpression suppressed thermogenesis. Our study presents that KCTD10 serves as an upstream regulator of notch signaling pathway to regulate BAT thermogenesis and whole-body metabolic function.


Endocrinology ◽  
2013 ◽  
Vol 154 (9) ◽  
pp. 3141-3151 ◽  
Author(s):  
D. Tews ◽  
P. Fischer-Posovszky ◽  
T. Fromme ◽  
M. Klingenspor ◽  
J. Fischer ◽  
...  

Variants in the fat mass- and obesity-associated (FTO) gene are associated with obesity and body fat mass in genome-wide association studies. However, the mechanism by which FTO predisposes individuals to obesity is not clear so far. First mechanistic evidence was shown in Fto-negative mice. These mice are resistant to obesity due to enhanced energy expenditure, whereas the mass of brown adipose tissue remains unchanged. We hypothesize that FTO is involved in the induction of white adipose tissue browning, which leads to mitochondrial uncoupling and increases energy expenditure. Uncoupling protein 1 (Ucp-1) was significantly higher expressed in both gonadal and inguinal adipose depots of Fto−/− compared with Fto+/+ littermates accompanied by the appearance of multivacuolar, Ucp-1-positive adipocytes in these tissues. By using lentiviral short hairpin RNA constructs, we established FTO-deficient human preadipocytes and adipocytes and analyzed key metabolic processes. FTO-deficient adipocytes showed an adipogenic differentiation rate comparable with control cells but exhibited a reduced de novo lipogenesis despite unchanged glucose uptake. In agreement with the mouse data, FTO-deficient adipocytes exhibited 4-fold higher expression of UCP-1 in mitochondria compared with control cells. The up-regulation of UCP-1 in FTO-deficient adipocytes resulted in enhanced mitochondrial uncoupling. We conclude that FTO deficiency leads to the induction of a brown adipocyte phenotype, thereby enhancing energy expenditure. Further understanding of the signaling pathway connecting FTO with UCP-1 expression might lead to new options for obesity and overweight treatment.


2016 ◽  
Vol 36 (15) ◽  
pp. 2027-2038 ◽  
Author(s):  
Hongyi Zhou ◽  
Stephen M. Black ◽  
Tyler W. Benson ◽  
Neal L. Weintraub ◽  
Weiqin Chen

Brown adipose tissue (BAT) plays a unique role in regulating whole-body energy homeostasis by dissipating energy through thermogenic uncoupling. Berardinelli-Seip congenital lipodystrophy (BSCL) type 2 (BSCL2; also known as seipin) is a lipodystrophy-associated endoplasmic reticulum membrane protein essential for white adipocyte differentiation. Whether BSCL2 directly participates in brown adipocyte differentiation, development, and function, however, is unknown. We show that BSCL2 expression is increased during brown adipocyte differentiation. Its deletion does not impair the classic brown adipogenic program but rather induces premature activation of differentiating brown adipocytes through cyclic AMP (cAMP)/protein kinase A (PKA)-mediated lipolysis and fatty acid and glucose oxidation, as well as uncoupling. cAMP/PKA signaling is physiologically activated during neonatal BAT development in wild-type mice and greatly potentiated in mice with genetic deletion ofBscl2in brown progenitor cells, leading to reduced BAT mass and lipid content during neonatal brown fat formation. However, prolonged overactivation of cAMP/PKA signaling during BAT development ultimately causes apoptosis of brown adipocytes through inflammation, resulting in BAT atrophy and increased overall adiposity in adult mice. These findings reveal a key cell-autonomous role for BSCL2 in controlling BAT mass/activity and provide novel insights into therapeutic strategies targeting cAMP/PKA signaling to regulate brown adipocyte function, viability, and metabolic homeostasis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Abhijit Babaji Shinde ◽  
Anying Song ◽  
Qiong A. Wang

Brown adipocyte in brown adipose tissue (BAT) specializes in expending energy through non-shivering thermogenesis, a process that produces heat either by uncoupling protein 1 (UCP1) dependent uncoupling of mitochondrial respiration or by UCP1 independent mechanisms. Apart from this, there is ample evidence suggesting that BAT has an endocrine function. Studies in rodents point toward its vital roles in glucose and lipid homeostasis, making it an important therapeutic target for treating metabolic disorders related to morbidities such as obesity and type 2 diabetes. The rediscovery of thermogenically active BAT depots in humans by several independent research groups in the last decade has revitalized interest in BAT as an even more promising therapeutic intervention. Over the last few years, there has been overwhelming interest in understanding brown adipocyte’s developmental lineages and how brown adipocyte uniquely utilizes energy beyond UCP1 mediated uncoupling respiration. These new discoveries would be leveraged for designing novel therapeutic interventions for metabolic disorders.


2019 ◽  
Vol 317 (5) ◽  
pp. E742-E750 ◽  
Author(s):  
Tania Quesada-López ◽  
Aleix Gavaldà-Navarro ◽  
Samantha Morón-Ros ◽  
Laura Campderrós ◽  
Roser Iglesias ◽  
...  

Adaptive induction of thermogenesis in brown adipose tissue (BAT) is essential for the survival of mammals after birth. We show here that G protein-coupled receptor protein 120 (GPR120) expression is dramatically induced after birth in mouse BAT. GPR120 expression in neonatal BAT is the highest among GPR120-expressing tissues in the mouse at any developmental stage tested. The induction of GPR120 in neonatal BAT is caused by postnatal thermal stress rather than by the initiation of suckling. GPR120-null neonates were found to be relatively intolerant to cold: close to one-third did not survive at 21°C, but all such pups survived at 25°C. Heat production in BAT was significantly impaired in GPR120-null pups. Deficiency in GPR120 did not modify brown adipocyte morphology or the anatomical architecture of BAT, as assessed by electron microscopy, but instead impaired the expression of uncoupling protein-1 and the fatty acid oxidation capacity of neonatal BAT. Moreover, GPR120 deficiency impaired fibroblast growth factor 21 (FGF21) gene expression in BAT and reduced plasma FGF21 levels. These results indicate that GPR120 is essential for neonatal adaptive thermogenesis.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Daisuke Irie ◽  
Hiroyuki Yamada ◽  
Taku Kato ◽  
Hiroyuki Kawahito ◽  
Kouji Ikeda ◽  
...  

[BACKGROUND] The angiotensin II type 1 (AT1) receptor in visceral white adipose tissue (WAT) is closely implicated in lipid metabolism and energy homeostasis. Recently, perivascular adipose tissue (PVAT) has been shown to play a crucial role in the development of atherosclerosis; however, the effects of AT1 on PVAT properties and their functional relevance in atherogenesis remain undefined. [METHOD AND RESULT] We examined the fat depot-specific difference of adipose tissue among epididymal WAT, PVAT surrounding thoracic aorta, and interscapular brown adipose tissue (BAT) in 8-week-old apoE deficient (apoE-/-) mice. The expression levels of brown adipocyte marker genes (UCP-1, PGC-1α, Elovl3, PPARα, and Cidea) were significantly higher in BAT and PVAT compared with WAT (P<0.01). White adipocyte marker genes (Igfbp3, DPT, Tcf21, and Hoxc9), which were hardly expressed in BAT, showed a moderate expression levels in PVAT, suggesting that PVAT has a strikingly different phenotype from the classical WAT and BAT. We next examined the properties of PVAT in 8-week-old apoE-/-/AT1 receptor deficient (Agtr1-/-) mice. After 4 weeks of western diet, the expression levels of adipocyte differentiation maker genes (PPARγ, FABP4, c/EBPα) were markedly increased in apoE -/- PVAT (P<0.05), which was completely diminished in apoE-/-/Agtr1 -/- PVAT (P<0.01). To investigate the effect of AT1 on the periaortic adipocyte differentiation, we performed primary culture of preadipocyte from stromal vascular fraction in Agtr1 -/- and Agtr1+/+ PVAT. The mRNA expressions of adipocyte differentiation marker genes (PPARγ, FABP4, and c/EBPα) were time-dependently increased in Agtr1+/+ adipocyte. In contrast, FABP4 and c/EBPα mRNA expressions were markedly inhibited in Agtr1 -/- adipocyte, whereas PPARγ did not differ between the two groups during differentiation, suggesting that AT1 is essentially implicated in the terminal differentiation of periaortic adipocyte. [CONCLUSION] Our findings demonstrate that AT1 regulates the expression levels of late stage of adipocyte-differentiation marker genes in PVAT, suggesting that AT1-mediated modulation of periaortic adipocyte differentiation could be a novel therapeutic target for the prevention of atherosclerosis.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Clarissa S. Craft ◽  
Hero Robles ◽  
Madelyn R. Lorenz ◽  
Eric D. Hilker ◽  
Kristann L. Magee ◽  
...  

AbstractAdipocytes within the skeleton are collectively termed bone marrow adipose tissue (BMAT). BMAT contributes to peripheral and local metabolism, however, its capacity for cell-autonomous expression of uncoupling protein 1 (UCP1), a biomarker of beige and brown adipogenesis, remains unclear. To overcome this, Ucp1-Cre was used to drive diphtheria toxin expression in cells expressing UCP1 (Ucp1Cre+/DTA+). Despite loss of brown adipose tissue, BMAT volume was not reduced in Ucp1Cre+/DTA+ mice. Comparably, in mTmG reporter mice (Ucp1Cre+/mTmG+), Ucp1-Cre expression was absent from BMAT in young (3-weeks) and mature (16-weeks) male and female mice. Further, β3-agonist stimulation failed to induce Ucp1-Cre expression in BMAT. This demonstrates that BMAT adipocytes are not UCP1-expressing beige/brown adipocytes. Thus, to identify novel and emerging roles for BMAT adipocytes in skeletal and whole-body homeostasis, we performed gene enrichment analysis of microarray data from adipose tissues of adult rabbits. Pathway analysis revealed genetic evidence for differences in BMAT including insulin resistance, decreased fatty acid metabolism, and enhanced contributions to local processes including bone mineral density through candidate genes such as osteopontin. In sum, this supports a paradigm by which BMAT adipocytes are a unique subpopulation that is specialized to support cells within the skeletal and hematopoietic niche.


2016 ◽  
Vol 311 (1) ◽  
pp. R79-R88 ◽  
Author(s):  
Lorna M. Dickson ◽  
Shriya Gandhi ◽  
Brian T. Layden ◽  
Ronald N. Cohen ◽  
Barton Wicksteed

Adipose tissue PKA has roles in adipogenesis, lipolysis, and mitochondrial function. PKA transduces the cAMP signal downstream of G protein-coupled receptors, which are being explored for therapeutic manipulation to reduce obesity and improve metabolic health. This study aimed to determine the overall physiological consequences of PKA activation in adipose tissue. Mice expressing an activated PKA catalytic subunit in adipose tissue (Adipoq-caPKA mice) showed increased PKA activity in subcutaneous, epididymal, and mesenteric white adipose tissue (WAT) depots and brown adipose tissue (BAT) compared with controls. Adipoq-caPKA mice weaned onto a high-fat diet (HFD) or switched to the HFD at 26 wk of age were protected from diet-induced weight gain. Metabolic health was improved, with enhanced insulin sensitivity, glucose tolerance, and β-cell function. Adipose tissue health was improved, with smaller adipocyte size and reduced macrophage engulfment of adipocytes. Using metabolic cages, we found that Adipoq-caPKA mice were shown to have increased energy expenditure, but no difference to littermate controls in physical activity or food consumption. Immunoblotting of adipose tissue showed increased expression of uncoupling protein-1 (UCP1) in BAT and dramatic UCP1 induction in subcutaneous WAT, but no induction in the visceral depots. Feeding a HFD increased PKA activity in epididymal WAT of wild-type mice compared with chow, but did not change PKA activity in subcutaneous WAT or BAT. This was associated with changes in PKA regulatory subunit expression. This study shows that adipose tissue PKA activity is sufficient to increase energy expenditure and indicates that PKA is a beneficial target in metabolic health.


2019 ◽  
Vol 51 (10) ◽  
pp. 678-685 ◽  
Author(s):  
Luka Levata ◽  
Riccardo Dore ◽  
Olaf Jöhren ◽  
Markus Schwaninger ◽  
Carla Schulz ◽  
...  

AbstractNesfatin-1 has originally been established as a bioactive peptide interacting with key hypothalamic nuclei and neural circuitries in control of feeding behavior, while its effect on energy expenditure has only recently been investigated. Hence, the aim of this study was to examine whether centrally acting nesfatin-1 can induce β3-adrenergic stimulation, which is a prerequisite for the activation of thermogenic genes and heat release from interscapular brown adipose tissue, key physiological features that underlie increased energy expenditure. This question was addressed in non-fasted mice stereotactically cannulated to receive nesfatin-1 intracerebroventricularly together with peripheral injection of the β3-adrenoceptor antagonist SR 59230 A, to assess whole-body energy metabolism. Using a minimally invasive thermography technique, we now demonstrate that the thermogenic effect of an anorectic nesfatin-1 dose critically depends on β3 adrenergic stimulation, as the co-administration with SR 59230 A completely abolished heat production from interscapular brown adipose tissue and rise in ocular surface temperature, thus preventing body weight loss. Moreover, through indirect calorimetry it could be shown that the anorectic concentration of nesfatin-1 augments overall caloric expenditure. Plausibly, central administration of nesfatin-1 also enhanced the expression of DIO2 and CIDEA mRNA in brown adipose tissue critically involved in the regulation of thermogenesis.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Won Kon Kim ◽  
Baek-Soo Han

Abstract Brown adipocytes play important roles in the regulation of energy homeostasis by uncoupling protein 1-mediated non-shivering thermogenesis. Recent studies suggest that brown adipocytes as novel therapeutic targets for combating obesity and associated diseases, such as type II diabetes. However, the molecular mechanisms underlying brown adipocyte differentiation and function are not fully understood. We employed previous findings obtained through proteomic studies performed to assess proteins displaying altered levels during brown adipocyte differentiation. Here, we performed assays to determine the functional significance of their altered levels during brown adipogenesis and development. We identified isocitrate dehydrogenase 1 (IDH1) as upregulated during brown adipocyte differentiation, with subsequent investigations revealing that ectopic expression of IDH1 inhibited brown adipogenesis, whereas suppression of IDH1 levels promoted differentiation of brown adipocytes. Additionally, Idh1 overexpression resulted in increased levels of intracellular α-ketoglutarate (α-KG) and inhibited the expression of genes involved in brown adipogenesis. Exogenous treatment with α-KG reduced brown adipogenesis during the early phase of differentiation, and ChIP analysis revealed that IDH1-mediated α-KG reduced trimethylation of histone H3 lysine 4 in the promoters of genes associated with brown adipogenesis. Furthermore, administration of α-KG decreased adipogenic gene expression by modulating histone methylation in brown adipose tissues of mice. These results suggested that the IDH1–α-KG axis plays an important role in regulating brown adipocyte differentiation and might represent a therapeutic target for treating metabolic diseases.


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