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Dlasková A, Clarke KJ, Rooney MF, Porter RK. The Use of Reactive Oxygen Species Production by Succinate-Driven Reverse Electron Flow as an Index of Complex 1 Activity in Isolated Brown Adipose Tissue Mitochondria. Methods Mol Biol 2021; 2310:247-258. [PMID: 34096006 DOI: 10.1007/978-1-0716-1433-4_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We compared the activity of complex 1, complex 2, and the expression of the complex 1 subunit, NDUFA9, in isolated brown adipose tissue mitochondria from wild type and mitochondrial uncoupling protein 1 (UCP1) knockout mice. Direct spectrophotometric measurement revealed that complex 2 activity was similar, but complex 1 activity was greater (~2.7 fold) in isolated mitochondria from wild-type mice compared to UCP1 knockout mice, an observation endorsed by greater complex 1 subunit expression (NDUFA9) in mitochondria of wild-type mice. We also measured reactive oxygen species (ROS) production by isolated brown adipose mitochondria respiring on succinate, without rotenone, thus facilitating reverse electron flow through complex 1. We observed that reverse electron flow in isolated mitochondria from wild-type mice, with UCP1 inhibited, produced significantly greater (~1.6 fold) ROS when compared with isolated brown adipose mitochondria from UCP1 knockout mice. In summary, we demonstrate that ROS production by succinate-driven reverse electron flow can occur in brown adipose tissue mitochondria and is a good index of complex 1 activity.
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Affiliation(s)
- Andrea Dlasková
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Kieran J Clarke
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Mary F Rooney
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Richard K Porter
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
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Qiao X, Kim DI, Jun H, Ma Y, Knights AJ, Park MJ, Zhu K, Lipinski JH, Liao J, Li Y, Richard S, Weinman SA, Wu J. Protein Arginine Methyltransferase 1 Interacts With PGC1α and Modulates Thermogenic Fat Activation. Endocrinology 2019; 160:2773-2786. [PMID: 31555811 PMCID: PMC6853686 DOI: 10.1210/en.2019-00504] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/11/2019] [Indexed: 02/06/2023]
Abstract
Protein arginine methyltransferases (PRMTs) are enzymes that regulate the evolutionarily conserved process of arginine methylation. It has been reported that PRMTs are involved in many metabolic regulatory pathways. However, until now, their roles in adipocyte function, especially browning and thermogenesis, have not been evaluated. Even though Prmt1 adipocyte-specific-deleted mice (Prmt1fl/flAQcre) appeared normal at basal level, following cold exposure or β-adrenergic stimulation, impaired induction of the thermogenic program was observed in both the interscapular brown adipose tissue and inguinal white adipose tissue of Prmt1fl/flAQcre mice compared with littermate controls. Different splicing variants of Prmt1 have been reported. Among them, PRMT1 variant 1 and PRMT1 variant 2 (PRMT1V2) are well conserved between humans and mice. Both variants contribute to the activation of thermogenic fat, with PRMT1V2 playing a more dominant role. Mechanistic studies using cultured murine and human adipocytes revealed that PRMT1V2 mediates thermogenic fat activation through PGC1α, a transcriptional coactivator that has been shown to play a key role in mitochondrial biogenesis. To our knowledge, our data are the first to demonstrate that PRMT1 plays a regulatory role in thermogenic fat function. These findings suggest that modulating PRMT1 activity may represent new avenues to regulate thermogenic fat and mediate energy homeostasis. This function is conserved in human primary adipocytes, suggesting that further investigation of this pathway may ultimately lead to therapeutic strategies against human obesity and associated metabolic disorders.
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Affiliation(s)
- Xiaona Qiao
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Dong-il Kim
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea
| | - Heejin Jun
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Yingxu Ma
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Cardiology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | | | - Min-Jung Park
- Department of Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea
| | - Kezhou Zhu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Jay H Lipinski
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Jiling Liao
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Endocrinology and Metabolism, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yiming Li
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Stéphane Richard
- Terry Fox Molecular Oncology Group and Bloomfield Center for Research on Aging, Segal Cancer Centre, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada
- Department of Oncology and Medicine, McGill University, Montreal, Quebec, Canada
| | - Steven A Weinman
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas
- Liver Center, University of Kansas Medical Center, Kansas City, Kansas
| | - Jun Wu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
- Correspondence: Jun Wu, PhD, Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Room 5115A, Ann Arbor, Michigan 48109. E-mail:
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Park J, Kim HL, Jung Y, Ahn KS, Kwak HJ, Um JY. Bitter Orange (Citrus aurantium Linné) Improves Obesity by Regulating Adipogenesis and Thermogenesis through AMPK Activation. Nutrients 2019; 11:nu11091988. [PMID: 31443565 PMCID: PMC6770725 DOI: 10.3390/nu11091988] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/09/2019] [Accepted: 08/18/2019] [Indexed: 12/19/2022] Open
Abstract
Obesity is a global health threat. Herein, we evaluated the underlying mechanism of anti-obese features of bitter orange (Citrus aurantium Linné, CA). Eight-week-administration of CA in high fat diet-induced obese C57BL/6 mice resulted in a significant decrease of body weight, adipose tissue weight and serum cholesterol. In further in vitro studies, we observed decreased lipid droplets in CA-treated 3T3-L1 adipocytes. Suppressed peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha indicated CA-inhibited adipogenesis. Moreover, CA-treated primary cultured brown adipocytes displayed increased differentiation associated with elevation of thermogenic factors including uncoupling protein 1 and PPARγ coactivator 1 alpha as well. The effects of CA in both adipocytes were abolished in AMP-activated protein kinase alpha (AMPKα)-suppressed environments, suggesting the anti-adipogenic and pro-thermogenic actions of CA were dependent on AMPKα pathway. In conclusion, our results suggest CA as a potential anti-obese agent which regulates adipogenesis and thermogenesis via AMPKα.
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Affiliation(s)
- Jinbong Park
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea
- Basic Research Laboratory for Comorbidity Regulation, Comorbidity Research Institute, Kyung Hee University, Seoul 02447, Korea
| | - Hye-Lin Kim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea
| | - Yunu Jung
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea
- Basic Research Laboratory for Comorbidity Regulation, Comorbidity Research Institute, Kyung Hee University, Seoul 02447, Korea
| | - Kwang Seok Ahn
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea
- Basic Research Laboratory for Comorbidity Regulation, Comorbidity Research Institute, Kyung Hee University, Seoul 02447, Korea
| | - Hyun Jeong Kwak
- Life science major, Division of Bio-convergence, College of convergence and integrate science, Kyonggi University, Suwon 16227, Korea.
| | - Jae-Young Um
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea.
- Basic Research Laboratory for Comorbidity Regulation, Comorbidity Research Institute, Kyung Hee University, Seoul 02447, Korea.
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Matesanz N, Nikolic I, Leiva M, Pulgarín-Alfaro M, Santamans AM, Bernardo E, Mora A, Herrera-Melle L, Rodríguez E, Beiroa D, Caballero A, Martín-García E, Acín-Pérez R, Hernández-Cosido L, Leiva-Vega L, Torres JL, Centeno F, Nebreda AR, Enríquez JA, Nogueiras R, Marcos M, Sabio G. p38α blocks brown adipose tissue thermogenesis through p38δ inhibition. PLoS Biol 2018; 16:e2004455. [PMID: 29979672 PMCID: PMC6051667 DOI: 10.1371/journal.pbio.2004455] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 07/18/2018] [Accepted: 06/15/2018] [Indexed: 02/06/2023] Open
Abstract
Adipose tissue has emerged as an important regulator of whole-body metabolism, and its capacity to dissipate energy in the form of heat has acquired a special relevance in recent years as potential treatment for obesity. In this context, the p38MAPK pathway has arisen as a key player in the thermogenic program because it is required for the activation of brown adipose tissue (BAT) thermogenesis and participates also in the transformation of white adipose tissue (WAT) into BAT-like depot called beige/brite tissue. Here, using mice that are deficient in p38α specifically in adipose tissue (p38αFab-KO), we unexpectedly found that lack of p38α protected against high-fat diet (HFD)-induced obesity. We also showed that p38αFab-KO mice presented higher energy expenditure due to increased BAT thermogenesis. Mechanistically, we found that lack of p38α resulted in the activation of the related protein kinase family member p38δ. Our results showed that p38δ is activated in BAT by cold exposure, and lack of this kinase specifically in adipose tissue (p38δ Fab-KO) resulted in overweight together with reduced energy expenditure and lower body and skin surface temperature in the BAT region. These observations indicate that p38α probably blocks BAT thermogenesis through p38δ inhibition. Consistent with the results obtained in animals, p38α was reduced in visceral and subcutaneous adipose tissue of subjects with obesity and was inversely correlated with body mass index (BMI). Altogether, we have elucidated a mechanism implicated in physiological BAT activation that has potential clinical implications for the treatment of obesity and related diseases such as diabetes.
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Affiliation(s)
- Nuria Matesanz
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Ivana Nikolic
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Magdalena Leiva
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Marta Pulgarín-Alfaro
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Ayelén M. Santamans
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Edgar Bernardo
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Alfonso Mora
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Leticia Herrera-Melle
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Elena Rodríguez
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Daniel Beiroa
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Ainoa Caballero
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Elena Martín-García
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Rebeca Acín-Pérez
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Lourdes Hernández-Cosido
- Bariatric Surgery Unit, Department of General Surgery, University Hospital of Salamanca, Salamanca, Spain
| | - Luis Leiva-Vega
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Jorge L. Torres
- Department of Internal Medicine, University Hospital of Salamanca-IBSAL, Department of Medicine, University of Salamanca, Salamanca, Spain
| | - Francisco Centeno
- Facultad de Ciencias, University of Extremadura, Grupo GIEN (Grupo de Investigación en Enfermedades Neurodegenerativas), Badajoz, Spain
| | - Angel R. Nebreda
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- ICREA, Barcelona, Spain
| | - José Antonio Enríquez
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
- CIBER Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Miguel Marcos
- Department of Internal Medicine, University Hospital of Salamanca-IBSAL, Department of Medicine, University of Salamanca, Salamanca, Spain
| | - Guadalupe Sabio
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
- * E-mail:
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Choi HR, Kim WK, Kim EY, Han BS, Min JK, Chi SW, Park SG, Bae KH, Lee SC. Dual-specificity phosphatase 10 controls brown adipocyte differentiation by modulating the phosphorylation of p38 mitogen-activated protein kinase. PLoS One 2013; 8:e72340. [PMID: 23977283 PMCID: PMC3748012 DOI: 10.1371/journal.pone.0072340] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/09/2013] [Indexed: 11/23/2022] Open
Abstract
Background Brown adipocytes play an important role in regulating the balance of energy, and as such, there is a strong correlation between obesity and the amount of brown adipose tissue. Although the molecular mechanism underlying white adipocyte differentiation has been well characterized, brown adipocyte differentiation has not been studied extensively. Here, we investigate the potential role of dual-specificity phosphatase 10 (DUSP10) in brown adipocyte differentiation using primary brown preadipocytes. Methods and Results The expression of DUSP10 increased continuously after the brown adipocyte differentiation of mouse primary brown preadipocytes, whereas the phosphorylation of p38 was significantly upregulated at an early stage of differentiation followed by steep downregulation. The overexpression of DUSP10 induced a decrease in the level of p38 phosphorylation, resulting in lower lipid accumulation than that in cells overexpressing the inactive mutant DUSP10. The expression levels of several brown adipocyte markers such as PGC-1α, UCP1, and PRDM16 were also significantly reduced upon the ectopic expression of DUSP10. Furthermore, decreased mitochondrial DNA content was detected in cells expressing DUSP10. The results obtained upon treatment with the p38 inhibitor, SB203580, clearly indicated that the phosphorylation of p38 at an early stage is important in brown adipocyte differentiation. The effect of the p38 inhibitor was partially recovered by DUSP10 knockdown using RNAi. Conclusions These results suggest that p38 phosphorylation is controlled by DUSP10 expression. Furthermore, p38 phosphorylation at an early stage is critical in brown adipocyte differentiation. Thus, the regulation of DUSP10 activity affects the efficiency of brown adipogenesis. Consequently, DUSP10 can be used as a novel target protein for the regulation of obesity.
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Affiliation(s)
- Hye-Ryung Choi
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Won Kon Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Eun Young Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Baek Soo Han
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
| | - Jeong-Ki Min
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
| | - Seung-Wook Chi
- Biomedical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Sung Goo Park
- Biomedical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Kwang-Hee Bae
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
- * E-mail: (KHB); (SCL)
| | - Sang Chul Lee
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
- * E-mail: (KHB); (SCL)
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Clarke KJ, Adams AE, Manzke LH, Pearson TW, Borchers CH, Porter RK. A role for ubiquitinylation and the cytosolic proteasome in turnover of mitochondrial uncoupling protein 1 (UCP1). Biochim Biophys Acta 2012; 1817:1759-67. [PMID: 22531154 DOI: 10.1016/j.bbabio.2012.03.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/23/2012] [Accepted: 03/29/2012] [Indexed: 11/19/2022]
Abstract
In this study we show that mitochondrial uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) and thymus mitochondria can be ubiquitinylated and degraded by the cytosolic proteasome. Using a ubiquitin conjugating system, we show that UCP1 can be ubiquitinylated in vitro. We demonstrate that UCP1 is ubiquitinylated in vivo using isolated mitochondria from brown adipose tissue, thymus and whole brown adipocytes. Using an in vitro ubiquitin conjugating-proteasome degradation system, we show that the cytosolic proteasome can degrade UCP1 at a rate commensurate with the half-life of UCP1 (i.e. 30-72h in brown adipocytes and ~3h, in thymocytes). In addition, we demonstrate that the cytoplasmic proteasome is required for UCP1 degradation from mitochondria that the process is inhibited by the proteasome inhibitor MG132 and that dissipation of the mitochondrial membrane potential inhibits degradation of UCP1. There also appears to be a greater amount of ubiquitinylated UCP1 associated with BAT mitochondria from cold-acclimated animals. We have also identified (using immunoprecipitation coupled with mass spectrometry) ubiquitinylated proteins with molecular masses greater than 32kDa, as being UCP1. We conclude that there is a role for ubiquitinylation and the cytosolic proteasome in turnover of mitochondrial UCP1. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).
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Affiliation(s)
- Kieran J Clarke
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Ireland
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Bettaieb A, Matsuo K, Matsuo I, Wang S, Melhem R, Koromilas AE, Haj FG. Protein tyrosine phosphatase 1B deficiency potentiates PERK/eIF2α signaling in brown adipocytes. PLoS One 2012; 7:e34412. [PMID: 22509299 PMCID: PMC3317973 DOI: 10.1371/journal.pone.0034412] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 02/27/2012] [Indexed: 12/02/2022] Open
Abstract
Background Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and body mass, and has been implicated in endoplasmic reticulum (ER) stress. Herein, we assess the role of PTP1B in ER stress in brown adipocytes, which are key regulators of thermogenesis and metabolic response. Methodology/Principal Findings To determine the role of PTP1B in ER stress, we utilized brown adipose tissue (BAT) from mice with adipose-specific PTP1B deletion, and brown adipocytes deficient in PTP1B and reconstituted with PTP1B wild type (WT) or the substrate-trapping PTP1B D181A (D/A) mutant. PTP1B deficiency led to upregulation of PERK-eIF2α phosphorylation and IRE1α-XBP1 sub-arms of the unfolded protein response. In addition, PTP1B deficiency sensitized differentiated brown adipocytes to chemical-induced ER stress. Moreover, PERK activation and tyrosine phosphorylation were increased in BAT and adipocytes lacking PTP1B. Increased PERK activity resulted in the induction of eIF2α phosphorylation at Ser51 and better translatability of ATF4 mRNA in response to ER stress. At the molecular level, we demonstrate direct interaction between PTP1B and PERK and identify PERK Tyr615 as a mediator of this association. Conclusions Collectively, the data demonstrate that PTP1B is a physiologically-relevant modulator of ER stress in brown adipocytes and that PTP1B deficiency modulates PERK-eIF2α phosphorylation and protein synthesis.
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Affiliation(s)
- Ahmed Bettaieb
- Department of Nutrition, University of California Davis, Davis, California, United States of America
| | - Kosuke Matsuo
- Department of Nutrition, University of California Davis, Davis, California, United States of America
| | - Izumi Matsuo
- Department of Nutrition, University of California Davis, Davis, California, United States of America
| | - Shuo Wang
- Lady Davis Institute for Medical Research, Sir Mortimer Davis-Jewish General Hospital, Montreal, Quebec, Canada
| | - Ramzi Melhem
- Department of Nutrition, University of California Davis, Davis, California, United States of America
| | - Antonis E. Koromilas
- Lady Davis Institute for Medical Research, Sir Mortimer Davis-Jewish General Hospital, Montreal, Quebec, Canada
- Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Fawaz G. Haj
- Department of Nutrition, University of California Davis, Davis, California, United States of America
- * E-mail:
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Momose A, Fujita M, Ohtomo T, Umemoto N, Tanonaka K, Toyoda H, Morikawa M, Yamada J. Regulated expression of acyl-CoA thioesterases in the differentiation of cultured rat brown adipocytes. Biochem Biophys Res Commun 2010; 404:74-8. [PMID: 21094633 DOI: 10.1016/j.bbrc.2010.11.066] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Accepted: 11/16/2010] [Indexed: 11/20/2022]
Abstract
Acyl-CoA thioesterases (ACOTs) are enzymes that catalyze the hydrolysis of fatty acyl-CoAs to free fatty acids and CoA-SH. In this study, we show that the expression profile of the ACOT isoforms changes remarkably during the differentiation of cultured rat brown adipocytes. Immunocytochemistry suggested that cytosolic ACOT1 was present in the preadipocytes, while mitochondrial ACOT2 was additionally expressed as the cells differentiated, concurrent with the accumulation of lipid droplets in the cytoplasm. Western blotting confirmed that, in contrast to ACOT1, the ACOT2 expression level was very low in the preadipocytes. However, after differentiation, the ACOT1 level fell to one-half of the baseline level and ACOT2 increased 18-fold. ACOT2 expression in the differentiated adipocytes was further enhanced by treatment with lipids or troglitazone. These changes in the ACOT2 expression level correlated well with changes in the expression of carnitine palmitoyltransferase 2, a mitochondrial β-oxidation enzyme. These results indicate that, in differentiating brown adipocytes, cytosolic ACOT1 becomes downregulated as the cellular use of acyl-CoA increases, while mitochondrial ACOT2 is upregulated as the β-oxidation capacity increases. ACOT isoform expression may be regulated during brown adipocyte differentiation to support the fat storage and combustion characteristics of this cell type.
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Affiliation(s)
- Atsushi Momose
- Department of Clinical Molecular Genetics, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
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Vila-Bedmar R, Lorenzo M, Fernández-Veledo S. Adenosine 5'-monophosphate-activated protein kinase-mammalian target of rapamycin cross talk regulates brown adipocyte differentiation. Endocrinology 2010; 151:980-92. [PMID: 20133456 DOI: 10.1210/en.2009-0810] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Brown adipose tissue (BAT) is considered of metabolic significance in mammalian physiology, because it plays an important role in regulating energy balance. Alterations in this tissue have been associated with obesity and type 2 diabetes. The molecular mechanisms modulating brown adipocyte differentiation are not fully understood. Using a murine brown preadipocyte cell line, primary cultures, and 3T3-L1 cells, we analyzed the contribution of various intracellular signaling pathways to adipogenic and thermogenic programs. Sequential activation of p38MAPK and LKB1-AMPK-tuberous sclerosis complex 2 (TSC2) as well as significant attenuation of ERK1/2 and mammalian target of rapamycin (mTOR)-p70 S6 kinase 1 (p70S6K1) activation was observed through the brown differentiation process. This study demonstrates a critical role for AMPK in controlling the mTOR-p70S6K1 signaling cascade in brown but not in 3T3-L1 adipocytes. We observed that mTOR activity is essential in the first stages of differentiation. Nevertheless, subsequent inhibition of this cascade by AMPK activation is also necessary at later stages. An in vivo study showed that prolonged 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR)-induced AMPK activation increases uncoupling protein 1 expression and induces an accumulation of brown adipocytes in white adipose tissue (WAT), as revealed by immunohistology. Moreover, the induction of brown adipogenesis in areas of white fat partially correlates with the body weight reduction detected in response to treatment with AICAR. Taken together, our study reveals that differentiation of brown adipocytes employs different signaling pathways from white adipocytes, with AMPK-mTOR cross talk a central mediator of this process. Promotion of BAT development in WAT by pharmacological activation of AMPK may have potential in treating obesity by acting on energy dissipation.
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Affiliation(s)
- Rocio Vila-Bedmar
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University, 28040 Madrid, Spain
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Murholm M, Dixen K, Qvortrup K, Hansen LHL, Amri EZ, Madsen L, Barbatelli G, Quistorff B, Hansen JB. Dynamic regulation of genes involved in mitochondrial DNA replication and transcription during mouse brown fat cell differentiation and recruitment. PLoS One 2009; 4:e8458. [PMID: 20107496 PMCID: PMC2809086 DOI: 10.1371/journal.pone.0008458] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 12/03/2009] [Indexed: 11/19/2022] Open
Abstract
Background Brown adipocytes are specialised in dissipating energy through adaptive thermogenesis, whereas white adipocytes are specialised in energy storage. These essentially opposite functions are possible for two reasons relating to mitochondria, namely expression of uncoupling protein 1 (UCP1) and a remarkably higher mitochondrial abundance in brown adipocytes. Methodology/Principal Findings Here we report a comprehensive characterisation of gene expression linked to mitochondrial DNA replication, transcription and function during white and brown fat cell differentiation in vitro as well as in white and brown fat, brown adipose tissue fractions and in selected adipose tissues during cold exposure. We find a massive induction of the majority of such genes during brown adipocyte differentiation and recruitment, e.g. of the mitochondrial transcription factors A (Tfam) and B2 (Tfb2m), whereas only a subset of the same genes were induced during white adipose conversion. In addition, PR domain containing 16 (PRDM16) was found to be expressed at substantially higher levels in brown compared to white pre-adipocytes and adipocytes. We demonstrate that forced expression of Tfam but not Tfb2m in brown adipocyte precursor cells promotes mitochondrial DNA replication, and that silencing of PRDM16 expression during brown fat cell differentiation blunts mitochondrial biogenesis and expression of brown fat cell markers. Conclusions/Significance Using both in vitro and in vivo model systems of white and brown fat cell differentiation, we report a detailed characterisation of gene expression linked to mitochondrial biogenesis and function. We find significant differences in differentiating white and brown adipocytes, which might explain the notable increase in mitochondrial content observed during brown adipose conversion. In addition, our data support a key role of PRDM16 in triggering brown adipocyte differentiation, including mitochondrial biogenesis and expression of UCP1.
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Affiliation(s)
- Maria Murholm
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Karen Dixen
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Klaus Qvortrup
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Lillian H. L. Hansen
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Ez-Zoubir Amri
- IBDC, Université de Nice Sophia-Antipolis, CNRS, UMR 6543, Nice, France
| | - Lise Madsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- National Institute of Nutrition and Seafood Research, Bergen, Norway
| | - Giorgio Barbatelli
- Department of Molecular Pathology and Innovative Therapies, School of Medicine, University of Ancona, Ancona, Italy
| | - Bjørn Quistorff
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jacob B. Hansen
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Abstract
White adipose tissue functions in energy storage and as an endocrine organ. DNA microarray analysis led us to identify Wdnm1-like, a distant member of the whey acidic protein/four-disulfide core (WAP/4-DSC) family, as a differentiation-dependent gene in white and brown adipogenesis. Wdnm1-like is a novel 6.8-kDa protein, and Western blot analysis reveals secretion into culture media. Wdnm1-like transcript is selectively expressed in adipose tissue and liver and is enriched approximately 500-fold in white adipose depots vs. brown. Cellular fractionation of WAT demonstrates Wdnm1-like transcript expression is restricted to the adipocyte population. Studies in 3T3-L1 preadipocytes, an in vitro model of white adipogenesis, indicate Wdnm1-like transcript increases within 6 h of adipogenic induction with an approximately 17,000-fold increase by day 7. Dramatic upregulation of Wdnm1-like also accompanies white adipogenesis of ScAP-23 preadipocytes and primary preadipocytes. TNF-alpha treatment of 3T3-L1 adipocytes increased Wdnm1-like transcript level 2.4-fold and was attenuated by pretreatment with the p38 MAP kinase inhibitor SB203580. A number of WAP/4-DSC family proteins function as protease inhibitors. This, taken with the role of extracellular remodeling in adipogenesis, led us to address effects of Wdnm1-like on matrix metalloproteinase (MMP) activity. Gelatin zymography of HT1080 fibrosarcoma cells transfected with a Wdnm1-like expression construct revealed markedly increased levels of active MMP-2. Our findings identify a new member of the adipocyte "secretome" that functions to enhance MMP-2 activity. We postulate that Wdnm1-like may play roles in remodeling of the extracellular milieu in adipogenesis, as well as in tumor microenvironments where adipocytes are key stromal components.
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Affiliation(s)
- Yu Wu
- Department of Biochemistry and Cancer Biology and Center for Diabetes and Endocrine Research, University of Toledo Health Science Campus, Toledo, OH 43614, USA
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12
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Abstract
Thyroid hormones act as pleiotropic factors in many tissues during development, by regulating genes involved in differentiation. The adipose tissue, a target of thyroid hormones, is the main place for energy storage and acts as a regulator of energy balance, sending signals to keep metabolic control. Adipogenesis is a complex process that involves proliferation of preadipocytes and its differentiation into mature adipocytes. This process is regulated by several transcription factors (CCAAT/enhancer-binding proteins [C/EBPs], peroxisome proliferator-activated receptors [PPARs]) that act coordinately, activating adipocyte-specific genes that will provide the adipocytic phenotype. Thyroid hormones regulate many of those genes, markers of differentiation of adipocytes, those involved in lipogenesis, lipolysis, and thermogenesis in the brown adipose tissue (BAT). Triiodothyronine (T3) actions are achieved either directly through specific thyroid response elements (TREs), by regulating other key genes as PPARs, or through specific isoforms of the nuclear T3 receptors. The availability of T3 is regulated through the deiodinases D3, D2, and D1. D3 is activated by serum and mitogens during proliferation of preadipocytes, while D2 is linked to the differentiation program of adipocytes, through the C/EBPs that govern its functionality, providing the T3 required for thermogenesis and lipogenesis. The relationship between white adipose tissue (WAT) and BAT and the possible reactivation of WAT by activation of uncoupling protein-1 (UCP1) is discussed.
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Affiliation(s)
- Maria-Jesus Obregon
- Instituto de Investigaciones Biomedicas, Centro mixto from Consejo Superior de Investigaciones Cientificas (CSIC), Universidad Autonoma de Madrid (UAM), Madrid, Spain.
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13
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Abstract
Active thyroid hormones are critical for the differentiation and function of brown adipose tissue. However, we have observed high basal and induced levels of type 3 deiodinase (D3), an enzyme that inactivates thyroid hormones and is coded by the imprinted gene Dio3, in differentiating brown preadipocytes in primary culture. We find that D3 activity and mRNA expression strongly correlate with the rate of proliferation of undifferentiated precursor cells under various conditions. Furthermore, differentiation of precursor cells to adipocytes is associated with decreased levels of D3 expression, and only very low levels of D3 mRNA are found in mature adipocytes. Dlk1, an inhibitor of adipocyte differentiation and a paternally expressed gene located in the same imprinted domain as Dio3, displayed changes in expression that parallel those of Dio3. In contrast, a 4-kb transcript for Dio3os, an antisense gene also located in the same imprinted domain, is markedly up-regulated in differentiated adipocytes. We conclude that D3 expression in differentiating preadipocytes is primarily linked to proliferating cells, whereas Dio3os expression is associated with mature adipocytes. Our results suggest that genomic imprinting and gene expression at the Dlk1/Dio3 imprinted domain may play a role in the regulation of adipocyte proliferation and differentiation.
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Affiliation(s)
- Arturo Hernandez
- Department of Medicine, Dartmouth Medical School, Borwell Building, Room 720W, Lebanon, New Hampshire 03755, USA.
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