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

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.

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Kelsey Hildreth ◽  
Haley Overby ◽  
Sean Kodani ◽  
Christophe Morisseau ◽  
Bruce Hammock ◽  
...  

Abstract Objectives Brown adipose tissue has recently emerged as a novel target for obesity treatment and prevention. In contrast to the lipid storing function of white adipocytes, brown adipocytes are responsible for dissipating energy as heat, a process involving uncoupling protein 1 (UCP1). Soluble epoxide hydrolase (sEH) is a cytosolic enzyme that converts epoxy fatty acids (EpFAs) into less active diols. By stabilizing endogenous EpFAs, potent small molecule sEH inhibitors have been shown to be beneficial for many chronic diseases. Several recent papers have reported that sEH inhibitors are able to reduce diet-induced obesity, possibly by upregulating UCP1 expression. In the current study, we sought to study the mechanisms by which sEH inhibitor acts on brown preadipocytes. Methods The effects of a potent sEH inhibitor, trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB), on murine brown adipocyte differentiation were evaluated by lipid accumulation and expression of brown adipocyte marker genes. PPAR alpha and PPAR gamma activation by t-AUCB was measured by their respective transactivation assays. The roles of PPARs were further studied by pharmacological antagonism and knockdown experiments by small RNA interference. Results We report that sEH expression was increased during murine brown adipocyte differentiation. t-AUCB dose-dependently promoted brown adipocyte differentiation. Moreover, we demonstrate that t-AUCB activated PPAR alpha, but not PPAR gamma. t-AUCB-induced upregulation of thermogenic gene Ucp1 and Pgc1 alpha and the general differentiation marker Fabp4 were significantly attenuated by the antagonist of PPAR alpha, GW6471. In contrast, they were only partially attenuated by the antagonist of PPAR gamma, GW9662, and specific knockdown of PPAR gamma. Conclusions Our findings suggest that sEH may regulate brown adipogenesis and sEH pharmacological inhibition by t-AUCB promotes brown adipogenesis, possibly through activation of PPAR alpha. Funding Sources The work is supported by NIH 1R15DK114790-01A1 (to LZ), R00DK100736 (to AB) and R01ES002710 (to BDH).


2014 ◽  
Vol 306 (4) ◽  
pp. E363-E372 ◽  
Author(s):  
Ruidan Xue ◽  
Yun Wan ◽  
Shuo Zhang ◽  
Qiongyue Zhang ◽  
Hongying Ye ◽  
...  

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.


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.


2002 ◽  
Vol 282 (1) ◽  
pp. C105-C112 ◽  
Author(s):  
Bibian García ◽  
Maria-Jesús Obregón

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.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saki Takayanagi ◽  
Kengo Watanabe ◽  
Takeshi Maruyama ◽  
Motoyuki Ogawa ◽  
Kazuhiro Morishita ◽  
...  

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.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1639-1639
Author(s):  
Katie Graham ◽  
Yang Yang ◽  
Ahmed Bettaieb ◽  
Ling Zhao

Abstract Objectives Brown adipocytes have emerged as novel targets for obesity treatment and prevention. Cytochrome P450 (CYP) epoxygenases, primarily CYP2J and CYP2C isoforms, produce epoxy fatty acids (EpFAs), which have been suggested to play important roles in the regulation of white adipogenesis and obesity. However, the roles of CYP epoxygenases in brown adipogenesis remain unexplored. In this study, we sought to characterize mRNA expression patterns of Cyp2j and 2c subfamily members during adipogenesis of human and murine brown adipocytes and in obese mice and investigate the impact of modulating the expression of Cyp2j13 on brown adipogenesis. Methods The mRNA expression of various Cyp2j and Cyp2c isoforms were examined throughout murine and human brown adipocyte differentiation and in the brown adipose tissue (BAT) of diet-induced obese and control mice. To induce epoxygenase overexpression, stable transfection of murine brown preadipocytes with either Cyp2j13 or a vector control was performed. Protein and mRNA expression of Cyp2j13 and brown marker genes were analyzed. Results Expression of murine Cyp2j isoforms Cyp2j6, Cyp2j8, Cyp2j9, and Cyp2j13, and the human isoform CYP2J2 consistently decreased throughout brown adipocyte differentiation, while expression of Cyp2c isoforms did not elicit consistent patterns. Moreover, Cyp2j expression in BAT was enhanced in diet-induced obese mice compared to the controls. Due to its high relative abundance and significance, Cyp2j13 was selected for further investigation. Overexpression of Cyp2j13 significantly suppressed murine brown adipocyte differentiation as evaluated by lipid accumulation and brown marker gene UCP1 expression. Conclusions Our results suggest that CYP epoxygenases may play important roles in brown adipogenesis. Cyp2j13, in particular, may be a novel target for brown adipogenesis, and consequently, for obesity treatment and prevention. Further studies using CYP2J inhibitors and Cyp2j13 knockdown are warranted. Funding Sources The work was supported by NIH 1R15DK114790–01A1 (to L.Z.), K99DK100736 and R00DK100736 (to A.B.).


2017 ◽  
Vol 58 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Rose Kohlie ◽  
Nina Perwitz ◽  
Julia Resch ◽  
Sebastian M Schmid ◽  
Hendrik Lehnert ◽  
...  

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.


PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jiamiao Hu ◽  
Arong Zhou ◽  
Peter C. K. Cheung ◽  
Baodong Zheng ◽  
Shaoxiao Zeng ◽  
...  

GPR43, a G-protein coupled receptor recognizing short-chain fatty acids, has been reported to participate in many biological functions of white adipocytes, such as adipogenesis and lipolysis. However, the functional role of GPR43 in brown adipocytes is still not clear. In this study, we investigated the effects of the PPARγ agonist rosiglitazone on GPR43 expression in brown adipogenesis. The results demonstrated that GPR43 was expressed during the late phase of brown adipocyte differentiation, which could be further augmented by adipogenic agent rosiglitazone treatment. The PPARγ/RXR heterodimerization was found to be the key transcription factor for this enhancing effect of rosiglitazone on GPR43 expression. Taken together, these results suggested GPR43 levels might be regulated by PPARγ-activated events during brown adipocytes differentiation and reflect the adipogenesis status of brown adipocytes.


2019 ◽  
Vol 11 (9) ◽  
pp. 781-790 ◽  
Author(s):  
Wen Meng ◽  
Xiuci Liang ◽  
Ting Xiao ◽  
Jing Wang ◽  
Jie Wen ◽  
...  

Abstract Increasing brown and beige fat thermogenesis have an anti-obesity effect and thus great metabolic benefits. However, the molecular mechanisms regulating brown and beige fat thermogenesis remain to be further elucidated. We recently found that fat-specific knockout of Rheb promoted beige fat thermogenesis. In the current study, we show that Rheb has distinct effects on thermogenic gene expression in brown and beige fat. Fat-specific knockout of Rheb decreased protein kinase A (PKA) activity and thermogenic gene expression in brown adipose tissue of high-fat diet-fed mice. On the other hand, overexpression of Rheb activated PKA and increased uncoupling protein 1 expression in brown adipocytes. Mechanistically, Rheb overexpression in brown adipocytes increased Notch expression, leading to disassociation of the regulatory subunit from the catalytic subunit of PKA and subsequent PKA activation. Our study demonstrates that Rheb, by selectively modulating thermogenic gene expression in brown and beige adipose tissues, plays an important role in regulating energy homeostasis.


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