The mineralocorticoid receptor mediates aldosterone-induced differentiation of T37i cells into brown adipocytes

2000 ◽  
Vol 279 (2) ◽  
pp. E386-E394 ◽  
Author(s):  
Patrice Penfornis ◽  
Say Viengchareun ◽  
Damien Le Menuet ◽  
Françoise Cluzeaud ◽  
Maria-Christina Zennaro ◽  
...  
Keyword(s):  
Cell Line ◽  
Mineralocorticoid Receptor ◽  
Uncoupling Protein ◽  
T Antigen ◽  
Proximal Promoter ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Aldosterone Antagonists ◽  
Fatty Acid Binding ◽  
Gene Markers

By use of targeted oncogenesis, a brown adipocyte cell line was derived from a hibernoma of a transgenic mouse carrying the proximal promoter of the human mineralocorticoid receptor (MR) linked to the SV40 large T antigen. T37i cells remain capable of differentiating into brown adipocytes upon insulin and triiodothyronine treatment as judged by their ability to express uncoupling protein 1 and maintain MR expression. Aldosterone treatment of undifferentiated cells induced accumulation of intracytoplasmic lipid droplets and mitochondria. This effect was accompanied by a significant and dose-dependent increase in intracellular triglyceride content (half-maximally effective dose 10−9 M) and involved MR, because it was unaffected by RU-38486 treatment but was totally abolished in the presence of aldosterone antagonists (spironolactone, RU-26752). The expression of early adipogenic gene markers, such as lipoprotein lipase, peroxisome proliferator-activated receptor-γ, and adipocyte-specific fatty acid binding protein 2, was enhanced by aldosterone, confirming activation of the differentiation process. We demonstrate that, in the T37i cell line, aldosterone participates in the very early induction of brown adipocyte differentiation. Our findings may have a broader biological significance and suggest that MR is not only implicated in maintaining electrolyte homeostasis but could also play a role in metabolism and energy balance.

Characterization of the novel brown adipocyte cell line HIB 1B. Adrenergic pathways involved in regulation of uncoupling protein gene expression

1994 ◽  
Vol 107 (1) ◽  
pp. 313-319 ◽  
Author(s):  
S. Klaus ◽  
L. Choy ◽  
O. Champigny ◽  
A.M. Cassard-Doulcier ◽  
S. Ross ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Line ◽  
Adrenergic Receptors ◽  
Uncoupling Protein ◽  
Primary Cultures ◽  
Brown Adipocyte ◽  
Mrna Levels ◽  
Adrenergic Agonists ◽  
Brown Adipocytes ◽  
Adipocyte Cell

The HIB 1B cell line, derived from a brown fat tumor of a transgenic mouse, is the first established brown adipocyte cell line capable of expressing the brown fat-specific mitochondrial uncoupling protein (UCP). UCP gene expression, which was virtually undetectable under basic conditions, was stimulated by acute catecholamine or cyclic AMP treatment to levels comparable to primary cultures of brown adipocytes. Elevation of UCP mRNA levels following stimulation was very rapid but transient, decreasing after about 4 hours with a half-life between 9 and 13 hours. Immunoblotting showed the presence of UCP in HIB 1B mitochondria, but expression was much lower than observed in BAT or primary cultures of brown adipocytes. Upon transfection of HIB 1B cells with a reporter gene containing the UCP promoter, the activity of the transgene was regulatable by cAMP and norepinephrine. Investigation of the possible adrenergic receptors involved in UCP stimulation showed that specific beta 3-adrenergic agonists were much less effective than nonspecific beta-adrenergic agonists and that mRNA levels of the atypical, fat-specific beta 3-adrenoceptor were lower than those observed in brown adipocytes differentiated in primary culture. From pharmacological evidence we conclude that beta 3-adrenergic receptors account for approximately 30–40% of catecholamine induced UCP gene stimulation, whereas about 60–70% is stimulated via the classical beta 1/2 adrenergic pathway. We conclude that HIB 1B cells represent a functional system for the study of mechanisms related to brown adipose thermogenesis.

Growth factor regulation of uncoupling protein-1 mRNA expression in brown adipocytes

2002 ◽  
Vol 282 (1) ◽  
pp. C105-C112 ◽  
Author(s):  
Bibian García ◽  
Maria-Jesús Obregón
Keyword(s):  
Growth Factor ◽  
Adipocyte Differentiation ◽  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Mrna Levels ◽  
Uncoupling Protein 1 ◽  
Brown Adipocytes ◽  
Proliferation And Differentiation ◽  
Epidermal Growth ◽  
Continuous Presence

To study the effect of the mitogens epidermal growth factor (EGF), acidic and basic fibroblast growth factors (aFGF and bFGF), and vasopressin on brown adipocyte differentiation, we analyzed the expression of uncoupling protein-1 (UCP-1) mRNA. Quiescent brown preadipocytes express high levels of UCP-1 mRNA in response to triiodothyronine (T3) and norepinephrine (NE). The addition of serum or the mitogenic condition aFGF + vasopressin + NE or EGF + vasopressin + NE decreases UCP-1 mRNA. A second addition of mitogens further decreases UCP-1 mRNA. Treatment with aFGF or bFGF alone increases UCP-1 mRNA, whereas the addition of EGF or vasopressin dramatically reduces UCP-1 mRNA levels. The continuous presence of T3 increases UCP-1 mRNA levels in cells treated with EGF, aFGF, or bFGF. The effect of T3 on the stimulation of DNA synthesis also was tested. T3 inhibits the mitogenic activity of aFGF and bFGF. In conclusion, mitogens like aFGF or bFGF allow brown adipocyte differentiation, whereas EGF and vasopressin inhibit the differentiation process. T3 behaves as an important hormone that regulates both brown adipocyte proliferation and differentiation.

scholarly journals ASKA technology-based pull-down method reveals a suppressive effect of ASK1 on the inflammatory NOD-RIPK2 pathway in brown adipocytes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saki Takayanagi ◽  
Kengo Watanabe ◽  
Takeshi Maruyama ◽  
Motoyuki Ogawa ◽  
Kazuhiro Morishita ◽  
...  
Keyword(s):  
Uncoupling Protein ◽  
Biological Significance ◽  
Suppressive Effect ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Adipose Tissues ◽  
Signaling Complex ◽  
Brown Adipose ◽  
Immune Pathway

AbstractRecent studies have shown that adipose tissue is an immunological organ. While inflammation in energy-storing white adipose tissues has been the focus of intense research, the regulatory mechanisms of inflammation in heat-producing brown adipose tissues remain largely unknown. We previously identified apoptosis signal-regulating kinase 1 (ASK1) as a critical regulator of brown adipocyte maturation; the PKA-ASK1-p38 axis facilitates uncoupling protein 1 (UCP1) induction cell-autonomously. Here, we show that ASK1 suppresses an innate immune pathway and contributes to maintenance of brown adipocytes. We report a novel chemical pull-down method for endogenous kinases using analog sensitive kinase allele (ASKA) technology and identify an ASK1 interactor in brown adipocytes, receptor-interacting serine/threonine-protein kinase 2 (RIPK2). ASK1 disrupts the RIPK2 signaling complex and inhibits the NOD-RIPK2 pathway to downregulate the production of inflammatory cytokines. As a potential biological significance, an in vitro model for intercellular regulation suggests that ASK1 facilitates the expression of UCP1 through the suppression of inflammatory cytokine production. In parallel to our previous report on the PKA-ASK1-p38 axis, our work raises the possibility of an auxiliary role of ASK1 in brown adipocyte maintenance through neutralizing the thermogenesis-suppressive effect of the NOD-RIPK2 pathway.

scholarly journals Dopamine directly increases mitochondrial mass and thermogenesis in brown adipocytes

2017 ◽  
Vol 58 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Rose Kohlie ◽  
Nina Perwitz ◽  
Julia Resch ◽  
Sebastian M Schmid ◽  
Hendrik Lehnert ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Energy Homeostasis ◽  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Peroxisome Proliferator ◽  
Cellular Mechanisms ◽  
Brown Adipocytes ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mitochondrial Mass ◽  
Brown Adipose

Brown adipose tissue (BAT) is key to energy homeostasis. By virtue of its thermogenic potential, it may dissipate excessive energy, regulate body weight and increase insulin sensitivity. Catecholamines are critically involved in the regulation of BAT thermogenesis, yet research has focussed on the effects of noradrenaline and adrenaline. Some evidence suggests a role of dopamine (DA) in BAT thermogenesis, but the cellular mechanisms involved have not been addressed. We employed our extensively characterised murine brown adipocyte cells. D1-like and D2-like receptors were detectable at the protein level. Stimulation with DA caused an increase in cAMP concentrations. Oxygen consumption rates (OCR), mitochondrial membrane potential (Δψm) and uncoupling protein 1 (UCP1) levels increased after 24 h of treatment with either DA or a D1-like specific receptor agonist. A D1-like receptor antagonist abolished the DA-mediated effect on OCR, Δψm and UCP1. DA induced the release of fatty acids, which did not additionally alter DA-mediated increases of OCR. Mitochondrial mass (as determined by (i) CCCP- and oligomycin-mediated effects on OCR and (ii) immunoblot analysis of mitochondrial proteins) also increased within 24 h. This was accompanied by an increase in peroxisome proliferator-activated receptor gamma co-activator 1 alpha protein levels. Also, DA caused an increase in p38 MAPK phosphorylation and pharmacological inhibition of p38 MAPK abolished the DA-mediated effect on Δψm. In summary, our study is the first to reveal direct D1-like receptor and p38 MAPK-mediated increases of thermogenesis and mitochondrial mass in brown adipocytes. These results expand our understanding of catecholaminergic effects on BAT thermogenesis.

scholarly journals SUN-587 IDH1-Dependent Alpha-KG Regulates Brown Fat Differentiation and Function by Modulating Histone Methylation

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Won Kon Kim ◽  
Baek-Soo Han
Keyword(s):  
Histone Methylation ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Uncoupling Protein ◽  
Ectopic Expression ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Brown Adipose ◽  
And Function ◽  
Brown Adipogenesis

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.

scholarly journals Synergism between cAMP and PPARγSignalling in the Initiation of UCP1 Gene Expression in HIB1B Brown Adipocytes

PPAR Research ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
H. Y. Chen ◽  
Q. Liu ◽  
A. M. Salter ◽  
M. A. Lomax
Keyword(s):  
Tandem Repeats ◽  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Specific Gene ◽  
Uncoupling Protein 1 ◽  
Brown Adipocytes ◽  
Promoter Construct ◽  
Ucp1 Expression ◽  
Signalling Systems ◽  
Antagonist Gw9662

Expression of the brown adipocyte-specific gene, uncoupling protein 1 (UCP1), is increased by both PPARγstimulation and cAMP activation through their ability to stimulate the expression of the PPAR coactivator PGC1α. In HIB1B brown preadipocytes, combination of the PPARγagonist, rosiglitazone, and the cAMP stimulator forskolin synergistically increased UCP1 mRNA expression, but PGC1αexpression was only increased additively by the two drugs. The PPARγantagonist, GW9662, and the PKA inhibitor, H89, both inhibited UCP1 expression stimulated by rosiglitazone and forskolin but PGC1αexpression was not altered to the same extent. Reporter studies demonstrated that combined rosiglitazone and forskolin synergistically activated transcription from a full length 3.1 kbp UCP1 luciferase promoter construct, but the response was only additive and much reduced when a minimal 260 bp proximal UCP1 promoter was examined. Rosiglitazone and forskolin in combination were able to synergistically stimulate promoters comprising of tandem repeats of either PPREs or CREs. We conclude that rosiglitazone and forskolin act together to synergistically activate the UCP1 promoter directly rather than by increasing PGC1αexpression and by a mechanism involving cross-talk between the signalling systems regulating the CRE and PPRE on the promoters.

Functional assessment of white and brown adipocyte development and energy metabolism in cell culture. Dissociation of terminal differentiation and thermogenesis in brown adipocytes

1995 ◽  
Vol 108 (10) ◽  
pp. 3171-3180
Author(s):  
S. Klaus ◽  
M. Ely ◽  
D. Encke ◽  
G. Heldmaier
Keyword(s):  
Uncoupling Protein ◽  
Terminal Differentiation ◽  
Brown Adipocyte ◽  
Index Number ◽  
Brown Adipocytes ◽  
White Adipocytes ◽  
Dwarf Hamster ◽  
Microscopy Analysis ◽  
White Fat ◽  
Adipocyte Development

We investigated the effect of insulin, triiodothyronine (T3) and dexamethasone (a synthetic glucocorticoid) on differentiation, lipid metabolism and thermogenesis of preadipocytes isolated from white fat (WAT) and brown fat (BAT) from the Siberian dwarf hamster (Phodopus sungorus). Cell cultures from WAT and BAT were chronically treated with the above hormones alone or in any combination. After differentiation (day 8 or 9 of culture) we measured the following parameters: adipogenic index (number × size of adipocytes), protein content, lipolysis, cell respiration, and expression of the uncoupling protein UCP, which is unique to mitochondria of brown adipocytes. Insulin was the most important adipogenic factor for brown and white adipocytes and necessary for terminal differentiation, whereas dexamethasone alone completely inhibited differentiation. T3 had no effect on adipogenesis in WAT cultures, but further increased insulin stimulated adipogenesis in BAT cultures. Basal lipolysis was higher in WAT than in BAT cultures except when dexamethasone was present, which stimulated lipolysis in both culture types to the same extent. T3 had a pronounced dose dependent lipolytic effect on WAT cultures but very little effect on BAT cultures. Respiration rates were generally higher in differentiated adipocytes than in fibroblast like cells. T3 had no effect on thermogenesis in WAT cultures but increased thermogenesis in BAT cultures, and this was further elevated by insulin. UCP expression in BAT cultures could be detected by western blot in insulin treated, T3 treated and insulin+T3 treated cultures with highest expression in the latter. These results imply a possible dissociation of terminal differentiation and thermogenic function of brown adipocytes. In WAT cultures there was also a low level of UCP detectable in the insulin+T3 treated cultures. Immuno-fluorescence microscopy analysis revealed the presence of UCP in 10–15% of adipocytes from WAT cultures (in BAT cultures: 90%), indicating the presence of some brown preadipocytes in typical WAT deposits.

Involvement of SIK2/TORC2 signaling cascade in the regulation of insulin-induced PGC-1α and UCP-1 gene expression in brown adipocytes

2009 ◽  
Vol 296 (6) ◽  
pp. E1430-E1439 ◽  
Author(s):  
Masaaki Muraoka ◽  
Aiko Fukushima ◽  
Say Viengchareun ◽  
Marc Lombès ◽  
Fukuko Kishi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Binding Protein ◽  
Uncoupling Protein ◽  
Brown Adipocytes ◽  
Adipose Tissues ◽  
Fatty Acid Binding ◽  
Diet Induced Obesity ◽  
Brown Adipose ◽  
The Impact

Salt-inducible kinase 2 (SIK2) is expressed abundantly in adipose tissues and represses cAMP-response element-binding protein (CREB)-mediated gene expression by phosphorylating the coactivator transducer of regulated CREB activity (TORC2). Phosphorylation at Ser587 of SIK2 diminishes its TORC2 phosphorylation activity. In 3T3-L1 white adipocytes, SIK2 downregulates lipogenic gene in response to nutritional stresses. To investigate the impact of SIK2 on the function of brown adipose tissue (BAT), we used T37i brown adipocytes, mice with diet-induced obesity, and SIK2 mutant (S587A) transgenic mice. When T37i adipocytes were treated with insulin, the levels of peroxisome proliferator-activated receptor-coactivator-1α ( PGC-1α) and uncoupling protein-1 ( UCP-1) mRNA were increased, and the induction was inhibited by overexpression of SIK2 (S587A) mutant or dominant-negative CREB. Insulin enhanced SIK2 phosphorylation at Ser587, which was accompanied by decrease in phospho-TORC2. Similarly, the decrease in the level of SIK2 phosphorylation at Ser587 was observed in the BAT of mice with diet-induced obesity, which was negatively correlated with TORC2 phosphorylation. To confirm the negative correlation between SIK2 phosphorylation at Ser587 and TORC2 phosphorylation in BAT, SIK2 mutant (S587A) was overexpressed in adipose tissues by using the adipocyte fatty acid-binding protein 2 promoter. The expression of recombinant SIK2 (S587A) was restricted to BAT, and the levels of phospho-TORC2 were elevated in BAT of transgenic mice. Male transgenic mice developed high-fat diet-induced obesity, and their BAT expressed low levels of PGC-1α and UCP-1 mRNA, suggesting that SIK2-TORC2 cascade may be important for the regulation of PGC-1α and UCP-1 gene expression in insulin signaling in BAT.

White, brite, and brown adipocytes: the evolution and function of a heater organ in mammals

2014 ◽  
Vol 92 (7) ◽  
pp. 615-626 ◽  
Author(s):  
Yongguo Li ◽  
David Lasar ◽  
Tobias Fromme ◽  
Martin Klingenspor
Keyword(s):  
Adipose Tissue ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Brown Fat ◽  
Brown Adipocyte ◽  
Nonshivering Thermogenesis ◽  
Inner Mitochondrial Membrane ◽  
Brown Adipocytes ◽  
Mitochondrial Density ◽  
Beige Adipocytes

Brown fat is a specialized heater organ in eutherian mammals. In contrast to the energy storage function of white adipocytes, brown adipocytes dissipate nutrient energy by uncoupling of mitochondrial oxidative phosphorylation, which depends on uncoupling protein 1 (UCP1). UCP1, as well as UCP2 and UCP3, belong to the family of mitochondrial carriers inserted into the inner mitochondrial membrane for metabolite trafficking between the matrix and the intermembrane space. UCP1 transports protons into the mitochondrial matrix when activated by a rise in free fatty acid levels in the cell. This UCP1-dependant proton leak drives high oxygen consumption rates in the absence of ATP synthesis and dissipates proton motive force as heat. The enormous heating capacity of brown fat is supported by dense vascularization, high rates of tissue perfusion, and high mitochondrial density in brown adipocytes. It has been known for more than 50 years that nonshivering thermogenesis in brown fat serves to maintain body temperature of neonates and small mammals in cold environments, and is used by hibernators for arousal from torpor. It has been speculated that the development of brown fat as a new source for nonshivering thermogenesis provided mammals with a unique advantage for survival in the cold. Indeed brown fat and UCP1 is found in ancient groups of mammals, like the afrotherians and marsupials. In the latter, however, the thermogenic function of UCP1 and brown fat has not been demonstrated as of yet. Notably, orthologs of all three mammalian UCP genes are also present in the genomes of bony fishes and in amphibians. Molecular phylogeny reveals a striking increase in the substitution rate of UCP1 between marsupial and eutherian lineages. At present, it seems that UCP1 only gained thermogenic function in brown adipocytes of eutherian mammals, whereas the function of UCP1 and that of the other UCPs in ectotherms remains to be identified. Evolution of thermogenic function required expression of UCP1 in a brown-adipocyte-like cell equipped with high mitochondrial density embedded in a well-vascularized tissue. Brown-adipocyte-like cells in white adipose tissue, called “brite” (brown-in-white) or “beige” adipocytes, emerge during adipogenesis and in response to cold exposure in anatomically distinct adipose tissue depots of juvenile and adult rodents. These brite adipocytes may resemble the archetypical brown adipocyte in vertebrate evolution. It is therefore of interest to elucidate the molecular mechanisms of brite adipocyte differentiation, study the bioenergetic properties of these cells, and search for the presence of related brown-adipocyte-like cells in nonmammalian vertebrates.

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