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.

Effects of age, gender, and senescence on β-adrenergic responses of isolated F344 rat brown adipocytes in vitro

1998 ◽  
Vol 274 (4) ◽  
pp. E726-E736 ◽  
Author(s):  
Annette M. Gabaldón ◽  
Roger B. McDonald ◽  
Barbara A. Horwitz
Keyword(s):  
Uncoupling Protein ◽  
Physiological State ◽  
Gender Effects ◽  
Rapid Weight Loss ◽  
Brown Adipocytes ◽  
Cl 316,243 ◽  
Age Related ◽  
Brown Adipose ◽  
Camp Levels

We previously reported greater age-related attenuation of cold-induced thermoregulation and brown adipose tissue thermogenic capacity in male vs. female F344 rats. With onset of the rapid weight loss that occurs near the end of the lifespan, this age-related attenuation becomes severe. We refer to this “end-of-life” physiological state of older rats as senescence. Here, we measured oxygen consumption of isolated brown adipocytes and found no age (6 vs. 12 vs. 26 mo) or gender effects on maximal norepinephrine (NE)- or CL-316,243 (β3-adrenergic agonist)-induced responses. In contrast, brown adipocytes from 22- to 26-mo-old senescent rats (males and females) consumed 51–60% less oxygen during maximal stimulation with NE and CL-316,243 than did cells from 26-mo-old presenescent rats. This attenuation was associated with lower (65–72%) uncoupling protein 1 concentrations but no alterations in NE-induced cAMP levels or lipolysis. Our data indicate that senescence, but not chronological age, significantly impacts NE-/β3-mediated thermogenesis of isolated brown adipocytes and that this effect involves altered mitochondrial rather than altered membrane or cytosol events.

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 In vitro and in vivo induction of brown adipocyte uncoupling protein (thermogenin) by retinoic acid

1996 ◽  
Vol 317 (3) ◽  
pp. 827-833 ◽  
Author(s):  
Pere PUIGSERVER ◽  
Francisca VÁZQUEZ ◽  
María L. BONET ◽  
Catalina PICÓ ◽  
Andreu PALOU
Keyword(s):  
Retinoic Acid ◽  
Cultured Cells ◽  
Uncoupling Protein ◽  
Primary Cultures ◽  
Brown Adipocyte ◽  
Brown Adipose ◽  
Adipocyte Cell ◽  
Differentiation Stage

The effects of retinoic acid (RA) isomers (all-trans-RA and 9-cis-RA) on the appearance of uncoupling protein (UCP; thermogenin), the only unequivocal molecular marker of the brown adipocyte differentiated phenotype, have been investigated in primary cultures of brown adipocytes, in the brown adipocyte cell line HIB 1B and directly in intact mice. The results obtained with cultured cells indicate that retinoids function as inducers of the appearance of UCP and, at the same time, partially inhibit brown adipocyte cell proliferation. The two RA isomers displayed similar effectiveness as UCP inducers, their effect being comparable with that triggered by noradrenaline, so far considered to be the main modulator of UCP gene expression. The effectiveness of retinoids as UCP inducers was dependent on the stage of brown adipocyte differentiation, being maximal in confluent primary cells and in the medium–late differentiation stage of HIB 1B cells. Corroborating the results obtained in vitro, we show that administration of all-trans-RA or 9-cis-RA to mice leads to an increase in their brown adipose tissue specific UCP content. 9-cis-RA treatment also prevented the loss of UCP on cold deacclimation. To our knowledge, this is the first report of a stimulatory effect of retinoid compounds on UCP induction in vivo.

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.

scholarly journals Essential roles of 11β-HSD1 in regulating brown adipocyte function

2012 ◽  
Vol 50 (1) ◽  
pp. 103-113 ◽  
Author(s):  
Juan Liu ◽  
Xiaocen Kong ◽  
Long Wang ◽  
Hanmei Qi ◽  
Wenjuan Di ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Fat ◽  
Brown Adipocyte ◽  
Specific Gene ◽  
Brown Adipocytes ◽  
Expression Of Genes ◽  
Brown Adipose ◽  
Attractive Therapeutic Target ◽  
And Function

Brown adipose tissue (BAT) increases energy expenditure and is an attractive therapeutic target for obesity. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1), an amplifier of local glucocorticoid activity, has been shown to modulate white adipose tissue (WAT) metabolism and function. In this study, we investigated the roles of 11β-HSD1 in regulating BAT function. We observed a significant increase in the expression of BAT-specific genes, including UCP1, Cidea, Cox7a1, and Cox8b, in BVT.2733 (a selective inhibitor of 11β-HSD1)-treated and 11β-HSD1-deficient primary brown adipocytes of mice. By contrast, a remarkable decrease in BAT-specific gene expression was detected in brown adipocytes when 11β-HSD1 was overexpressed, which effect was reversed by BVT.2733 treatment. Consistent with the in vitro results, expression of a range of genes related to brown fat function in high-fat diet-fed mice treated with BVT.2733. Our results indicate that 11β-HSD1 acts as a vital regulator that controls the expression of genes related to brown fat function and as such may become a potential target in preventing obesity.

Circulating pro fibrotic protein promotes fibrosis in liver

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Hsiao ◽  
I Shimizu ◽  
Y Yoshida ◽  
R Ikegami ◽  
Y Hayashi ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
High Fat Diet ◽  
In Vitro Studies ◽  
High Fat ◽  
Brown Adipocytes ◽  
Adipose Tissues ◽  
Nash Model ◽  
Brown Adipose

Abstract Background/Introduction Non-alcoholic steatohepatitis (NASH), driven by the obesity epidemic, has become the most common form of liver disease. Inflamed visceral adipose tissue secretes pro-inflammatory adipokines that are causal for systemic metabolic disorders. Role of adipokines in NASH, especially those from brown adipose tissues (BATokine) remain unclear. Purpose To show the pathogenic role of BATokine in NASH. Methods To identify and characterize the pathological roles of pro-fibrotic BATokine, we generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice, and murine systemic or BAT specific knockout (KO) models. We also conducted functional in-vitro studies with differentiated brown adipocytes. Results Analyzing two sets of DNA micro array data with bioinformatics, we identified a secreted form pro-fibrotic protein (sPFP) expressed in dysfunctional brown adipose tissues (BAT) in mice. Testing our biobank samples, we found this protein increased in plasma of NASH patients. We generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice for 9–10 months since 4 weeks of age, and found that sPFP is produced predominantly by BAT. In this model, we also found that sPFP increased in plasma. We generated a murine systemic or BAT specific sPFP knockout (KO) models and found that liver fibrosis ameliorated in these models. We also suppressed circulating sPFP with a peptide vaccine targeting this molecule, and found that sPFP vaccination therapy inhibited liver fibrosis. Next, we generated sPFP gain of function (GOF) model by the administration of plasmid encoding sPFP into skeletal muscle. Liver fibrosis augmented in sPFP-GOF model, and these results suggested that sPFP has causal role for the progression of fibrotic response in liver. In vitro studies with differentiated brown adipocytes showed that metabolic stress increased c-Fos in nuclear, and this was causal for an increase in sPFP level. Conclusions Our results suggest that one of the BATokines, sPFP, contributes for the progression of fibrotic responses in obese-NASH model. Inhibition of sPFP may become a therapy for NASH or obesity related fibrotic disorders. Funding Acknowledgement Type of funding source: None

Role of bone morphogenetic protein 4 in the differentiation of brown fat-like adipocytes

2014 ◽  
Vol 306 (4) ◽  
pp. E363-E372 ◽  
Author(s):  
Ruidan Xue ◽  
Yun Wan ◽  
Shuo Zhang ◽  
Qiongyue Zhang ◽  
Hongying Ye ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Uncoupling Protein ◽  
Brown Fat ◽  
Brown Adipocyte ◽  
White Adipocyte ◽  
Brown Adipose ◽  
And Function ◽  
Brown Adipogenesis

There are two different types of fat present in mammals: white adipose tissue, the primary site of energy storage, and brown adipose tissue, which is specializes in energy expenditure. Factors that specify the developmental fate and function of brown fat are poorly understood. Bone morphogenic proteins (BMPs) play an important role in adipogenesis. While BMP4 is capable of triggering commitment of stem cells to the white adipocyte lineage, BMP7 triggers commitment of progenitor cells to a brown adipocyte lineage and activates brown adipogenesis. To investigate the differential effects of BMPs on the development of adipocytes, C3H10T1/2 pluripotent cells were pretreated with BMP4 and BMP7, followed by different adipogenic induction cocktails. Both BMP4 and BMP7 unexpectedly activated a full program of brown adipogenesis, including induction of the brown fat-defining marker uncoupling protein-1 (UCP1), increasing the expression of early regulators of brown fat fate PRDM16 (PR domain-containing 16) and induction of mitochondrial biogenesis and function. Implantation of BMP4-pretreated C3H10T1/2 cells into nude mice resulted in the development of adipose tissue depots containing UCP1-positive brown adipocytes. Interestingly, BMP4 could also induce brown fat-like adipocytes in both white and brown preadipocytes, thereby decreasing the classical brown adipocyte marker Zic1 and increasing the recently identified beige adipocyte marker TMEM26. The data indicate an important role for BMP4 in promoting brown adipocyte differentiation and thermogenesis in vivo and in vitro and offers a potentially new therapeutic approach for the treatment of obesity.

scholarly journals Immunohistochemical identification of the uncoupling protein in rat brown adipose tissue.

1985 ◽  
Vol 33 (2) ◽  
pp. 150-154 ◽  
Author(s):  
M Cadrin ◽  
M Tolszczuk ◽  
J Guy ◽  
G Pelletier ◽  
K B Freeman ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Staining Technique ◽  
Cellular Heterogeneity ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Immunohistochemical Technique ◽  
Brown Adipose ◽  
Pap Method

Brown adipose tissue mitochondria are characterized by the presence of an uncoupling protein that gives them an exceptional capacity for substrate-controlled respiration and thermogenesis. The specific localization of this protein in rat brown adipocytes was demonstrated using an immunohistochemical technique, the peroxidase-antiperoxidase (PAP) method. Light microscopy observations showed that serum antibodies raised against the uncoupling protein selectively reacted with multilocular brown adipocytes. No labeling could be detected in either unilocular adipocytes, capillaries, or muscle fibers (striated and vascular smooth muscle). Staining was more intensive in certain adipocytes than in others, suggesting the presence of cellular heterogeneity. The specificity of the staining technique was demonstrated by showing that treatment of the preparations with antiserum saturated with an excess of uncoupling protein almost entirely inhibited brown adipocyte labeling. The specificity and selectivity of the PAP method allow the clear differentiation of uncoupling protein-containing adipocytes from other cellular types, suggesting that this immunohistochemical technique will represent an extremely useful tool for studying adipocyte function and differentiation.

scholarly journals Development of Phodopus sungorus brown preadipocytes in primary cell culture: effect of an atypical beta-adrenergic agonist, insulin, and triiodothyronine on differentiation, mitochondrial development, and expression of the uncoupling protein UCP.

1991 ◽  
Vol 115 (6) ◽  
pp. 1783-1790 ◽  
Author(s):  
S Klaus ◽  
A M Cassard-Doulcier ◽  
D Ricquier
Keyword(s):  
Uncoupling Protein ◽  
Phodopus Sungorus ◽  
Brown Adipocyte ◽  
Mrna Levels ◽  
Adrenergic Stimulation ◽  
Stimulatory Action ◽  
Beta Adrenergic ◽  
Brown Adipose ◽  
Dwarf Hamster

A new cellular model for the study of brown adipocyte development and differentiation in vitro is presented. Preadipocytes isolated from brown adipose tissue (BAT) of the djungarian dwarf hamster Phodopus sungorus are able to proliferate and differentiate in vitro into true brown adipocytes able to express the BAT marker protein the uncoupling protein (UCP). Whereas basal UCP expression is very low, its mRNA levels as well as the UCP detected by immunoblotting are highly increased by beta-adrenergic stimulation. The novel, atypical beta-adrenergic compound D7114 (ICI Pharmaceuticals, Macclesfield, Cheshire, England) was found to increase the number of adipocytes as well as UCP mRNA and UCP content of mitochondria, indicating the involvement of an atypical or beta 3 receptor. Insulin was found to play an important role in brown adipocyte differentiation and mitochondrial development, whereas T3 seemed to be implicated more directly in UCP expression. In a defined, serum-free medium a synergistic stimulatory action of insulin and T3 on UCP expression was found, which seems to involve a pathway different from that of beta-adrenergic UCP stimulation.

Sign in / Sign up

Export Citation Format

Share Document