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Beghini M, Wagner T, Luca AC, Metz M, Kaltenecker D, Spirk K, Hackl MT, Haybaeck J, Moriggl R, Kautzky-Willer A, Scherer T, Fürnsinn C. Adipocyte STAT5 deficiency does not affect blood glucose homeostasis in obese mice. PLoS One 2021; 16:e0260501. [PMID: 34818373 PMCID: PMC8612524 DOI: 10.1371/journal.pone.0260501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 11/10/2021] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to investigate whether the lack of signal transducer and activator of transcription 5 (STAT5) in mature adipocytes of obese mice (Stat5Adipoq mice) improves glucose and lipid metabolism as previously observed in lean mice. Male Stat5Adipoq mice and their wild type (WT) littermates were fed high-fat diet (HFD). Effects of adipocyte STAT5 deficiency on adiposity as well as on glucose and lipid metabolism were determined under ad libitum feeding and after weight loss induced by calorie restriction. Compared to WT mice, obese Stat5Adipoq mice showed modestly accelerated weight gain and blunted depletion of fat stores under calorie restriction (reduction in % body fat after 3 weeks: WT, -9.3±1.1, vs Stat5Adipoq, -5.9±0.8, p = 0.04). No differences were observed between Stat5Adipoq and WT mice with regard to parameters of glucose and lipid metabolism including basal glycaemia, glucose tolerance, and plasma triglycerides. In conclusion, STAT5 deficiency in the adipocyte of HFD-fed obese mice was associated with increased fat accumulation. In contrast to previous findings in lean mice, however, lipid accumulation was not associated with any improvement in glucose and lipid metabolism. Our results do not support adipocyte STAT5 as a promising target for the treatment of obesity-associated metabolic derangements.
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Affiliation(s)
- Marianna Beghini
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Theresia Wagner
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Andreea Corina Luca
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Matthäus Metz
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Doris Kaltenecker
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Katrin Spirk
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Martina Theresa Hackl
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Johannes Haybaeck
- Institute of Pathology, Neuropathology and Molecular Pathology, Medical University of Innsbruck, Innsbruck, Austria
- Diagnostic & Research Center for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Richard Moriggl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Alexandra Kautzky-Willer
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Thomas Scherer
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Clemens Fürnsinn
- Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
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52
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Grabner GF, Xie H, Schweiger M, Zechner R. Lipolysis: cellular mechanisms for lipid mobilization from fat stores. Nat Metab 2021; 3:1445-1465. [PMID: 34799702 DOI: 10.1038/s42255-021-00493-6] [Citation(s) in RCA: 221] [Impact Index Per Article: 73.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022]
Abstract
The perception that intracellular lipolysis is a straightforward process that releases fatty acids from fat stores in adipose tissue to generate energy has experienced major revisions over the last two decades. The discovery of new lipolytic enzymes and coregulators, the demonstration that lipophagy and lysosomal lipolysis contribute to the degradation of cellular lipid stores and the characterization of numerous factors and signalling pathways that regulate lipid hydrolysis on transcriptional and post-transcriptional levels have revolutionized our understanding of lipolysis. In this review, we focus on the mechanisms that facilitate intracellular fatty-acid mobilization, drawing on canonical and noncanonical enzymatic pathways. We summarize how intracellular lipolysis affects lipid-mediated signalling, metabolic regulation and energy homeostasis in multiple organs. Finally, we examine how these processes affect pathogenesis and how lipolysis may be targeted to potentially prevent or treat various diseases.
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Affiliation(s)
- Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Hao Xie
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
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53
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Kanshana JS, Mattila PE, Ewing MC, Wood AN, Schoiswohl G, Meyer AC, Kowalski A, Rosenthal SL, Gingras S, Kaufman BA, Lu R, Weeks DE, McGarvey ST, Minster RL, Hawley NL, Kershaw EE. A murine model of the human CREBRFR457Q obesity-risk variant does not influence energy or glucose homeostasis in response to nutritional stress. PLoS One 2021; 16:e0251895. [PMID: 34520472 PMCID: PMC8439463 DOI: 10.1371/journal.pone.0251895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023] Open
Abstract
Obesity and diabetes have strong heritable components, yet the genetic contributions to these diseases remain largely unexplained. In humans, a missense variant in Creb3 regulatory factor (CREBRF) [rs373863828 (p.Arg457Gln); CREBRFR457Q] is strongly associated with increased odds of obesity but decreased odds of diabetes. Although virtually nothing is known about CREBRF's mechanism of action, emerging evidence implicates it in the adaptive transcriptional response to nutritional stress downstream of TORC1. The objectives of this study were to generate a murine model with knockin of the orthologous variant in mice (CREBRFR458Q) and to test the hypothesis that this CREBRF variant promotes obesity and protects against diabetes by regulating energy and glucose homeostasis downstream of TORC1. To test this hypothesis, we performed extensive phenotypic analysis of CREBRFR458Q knockin mice at baseline and in response to acute (fasting/refeeding), chronic (low- and high-fat diet feeding), and extreme (prolonged fasting) nutritional stress as well as with pharmacological TORC1 inhibition, and aging to 52 weeks. The results demonstrate that the murine CREBRFR458Q model of the human CREBRFR457Q variant does not influence energy/glucose homeostasis in response to these interventions, with the exception of possible greater loss of fat relative to lean mass with age. Alternative preclinical models and/or studies in humans will be required to decipher the mechanisms linking this variant to human health and disease.
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Affiliation(s)
- Jitendra S. Kanshana
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Polly E. Mattila
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Michael C. Ewing
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Ashlee N. Wood
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Gabriele Schoiswohl
- Department of Pharmacology and Toxicology, University of Graz, Graz, Austria
| | - Anna C. Meyer
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Aneta Kowalski
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Samantha L. Rosenthal
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Sebastien Gingras
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Brett A. Kaufman
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Ray Lu
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Daniel E. Weeks
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Stephen T. McGarvey
- International Health Institute, Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island, United States of America
- Department of Anthropology, Brown University, Providence, Rhode Island, United States of America
| | - Ryan L. Minster
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nicola L. Hawley
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Erin E. Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
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54
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Zhang J, Shi Y, Yang C, Sun B, Ma H, Huang R, Li Z, Wang M, Wang Q, Ma J, Xiong X. Adipocyte-specific deletion of Depdc5 exacerbates insulin resistance and adipose tissue inflammation in mice. Biochem Biophys Res Commun 2021; 569:118-124. [PMID: 34243067 DOI: 10.1016/j.bbrc.2021.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 11/23/2022]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is a crucial regulator of adipogenesis and systemic energy metabolism. Its dysregulation leads to a diversity of metabolic diseases, including obesity and type 2 diabetes. DEP-domain containing 5 (DEPDC5) is a critical component of GATOR1 complex that functions as a key inhibitor of mTORC1. So far, its function in adipose tissue remains largely unknown. Herein we evaluated how persistent mTORC1 activation in adipocyte via Depdc5 knockout modulates adiposity in vivo. Our data indicated that adipocyte-specific knockout of Depdc5 in aged mice led to reduced visceral fat, aggravated insulin resistance and enhanced adipose tissue inflammation. Moreover, we found that Depdc5 ablation resulted in upregulation of adipose triglyceride lipase (ATGL) in adipocytes and elevated levels of serum free fatty acids (FFAs). Intriguingly, rapamycin treatment did not reverse insulin resistance but alleviated adipose tissue inflammation caused by Depdc5 deletion. Taken together, our findings revealed that mTORC1 activation caused by Depdc5 deletion promotes lipolysis process and further exacerbates insulin resistance and adipose tissue inflammation in mice.
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Affiliation(s)
- Jinghong Zhang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; College of Pharmacy,Xinxiang Medical University, Xinxiang, Henan, China
| | - Yiping Shi
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China; School of Basic Medical Sciences,Xinxiang Medical University, Xinxiang, Henan, China
| | - Chenyan Yang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Bo Sun
- College of Pharmacy,Xinxiang Medical University, Xinxiang, Henan, China
| | - Honghui Ma
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Rong Huang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Zun Li
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Mingyong Wang
- School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Qingzhi Wang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China
| | - Jie Ma
- School of Basic Medical Sciences,Xinxiang Medical University, Xinxiang, Henan, China.
| | - Xiwen Xiong
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, Henan, China.
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55
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Gallerand A, Stunault MI, Merlin J, Luehmann HP, Sultan DH, Firulyova MM, Magnone V, Khedher N, Jalil A, Dolfi B, Castiglione A, Dumont A, Ayrault M, Vaillant N, Gilleron J, Barbry P, Dombrowicz D, Mack M, Masson D, Bertero T, Becher B, Williams JW, Zaitsev K, Liu Y, Guinamard RR, Yvan-Charvet L, Ivanov S. Brown adipose tissue monocytes support tissue expansion. Nat Commun 2021; 12:5255. [PMID: 34489438 PMCID: PMC8421389 DOI: 10.1038/s41467-021-25616-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 08/12/2021] [Indexed: 12/24/2022] Open
Abstract
Monocytes are part of the mononuclear phagocytic system. Monocytes play a central role during inflammatory conditions and a better understanding of their dynamics might open therapeutic opportunities. In the present study, we focused on the characterization and impact of monocytes on brown adipose tissue (BAT) functions during tissue remodeling. Single-cell RNA sequencing analysis of BAT immune cells uncovered a large diversity in monocyte and macrophage populations. Fate-mapping experiments demonstrated that the BAT macrophage pool requires constant replenishment from monocytes. Using a genetic model of BAT expansion, we found that brown fat monocyte numbers were selectively increased in this scenario. This observation was confirmed using a CCR2-binding radiotracer and positron emission tomography. Importantly, in line with their tissue recruitment, blood monocyte counts were decreased while bone marrow hematopoiesis was not affected. Monocyte depletion prevented brown adipose tissue expansion and altered its architecture. Podoplanin engagement is strictly required for BAT expansion. Together, these data redefine the diversity of immune cells in the BAT and emphasize the role of monocyte recruitment for tissue remodeling. Adipose tissue is composed of a number of adipocytes and a number of other cells including immune cells. Here the authors use single-cell sequencing of murine brown adipose tissue immune cells and describe multiple macrophage and monocyte subsets and show that monocytes contribute to brown adipose tissue expansion.
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Affiliation(s)
| | | | | | - Hannah P Luehmann
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Deborah H Sultan
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Maria M Firulyova
- Computer Technologies Department, ITMO University, Saint Petersburg, Russia
| | | | | | - Antoine Jalil
- Université Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | | | | | | | | | | | | | - Pascal Barbry
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | - David Dombrowicz
- Univ.Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, Lille, France
| | - Matthias Mack
- Department of Internal Medicine - Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - David Masson
- Université Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | | | - Burkhard Becher
- Institute of Experimental Immunology, University of Zürich, Zürich, Switzerland
| | - Jesse W Williams
- Department of Integrative Biology and Physiology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Konstantin Zaitsev
- Computer Technologies Department, ITMO University, Saint Petersburg, Russia
| | - Yongjian Liu
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
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56
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Li H, Wang C, Zhao J, Guo C. JNK downregulation improves olanzapine-induced insulin resistance by suppressing IRS1 Ser307 phosphorylation and reducing inflammation. Biomed Pharmacother 2021; 142:112071. [PMID: 34449309 DOI: 10.1016/j.biopha.2021.112071] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/08/2021] [Accepted: 08/17/2021] [Indexed: 11/16/2022] Open
Abstract
AIMS c-jun N-terminal kinase (JNK) plays pivotal roles in many physiological processes, including inflammation and glucose metabolism. However, the effects of JNK on olanzapine-induced insulin resistance and the underlying mechanisms have not been fully elucidated. The aim of our study was to explore the role of JNK in olanzapine-induced insulin resistance and the underlying mechanisms. METHODS We studied glucose metabolism in olanzapine-treated female C57B/J mice and mice with adeno-associated virus (AAV)-mediated downregulation of JNK1 in epididymal white adipose tissue (eWAT). 3T3-L1 adipocytes were used to investigate the mechanism of JNK1 regulating insulin signaling after olanzapine treatment. RESULTS JNK was activated in eWAT after olanzapine treatment. JNK1 downregulation in eWAT ameliorated the insulin resistance and adipose tissue inflammation in olanzapine-treated mice. Furthermore, overexpression of JNK1 in adipocytes exacerbated the glucose disorder while JNK1 knockdown alleviated the impaired insulin signaling on olanzapine challenge, which was likely mediated by the reduced inflammation and insulin receptor substrate 1 (IRS1) phosphorylation. Moreover, the effect of JNK1 was attenuated by downregulation of IRS1 in adipocytes. Finally, the JNK1-IRS1 interaction and IRS1S307 phosphorylation were required for JNK1-regulated olanzapine-induced insulin resistance in adipocytes. CONCLUSIONS Our results demonstrated that JNK1 activation by olanzapine induced insulin resistance by promoting IRS1Ser307 phosphorylation and inflammation in eWAT. These results highlighted the importance of JNK1 in eWAT as a promising drug target for olanzapine-induced insulin resistance.
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Affiliation(s)
- Huqun Li
- Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China
| | - Chongshu Wang
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiefang Zhao
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cuilian Guo
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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57
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Dipta P, Sarsenbayeva A, Shmuel M, Forno F, Eriksson JW, Pereira MJ, Abalo XM, Wabitsch M, Thaysen-Andersen M, Tirosh B. Macrophage-derived secretome is sufficient to confer olanzapine-mediated insulin resistance in human adipocytes. COMPREHENSIVE PSYCHONEUROENDOCRINOLOGY 2021; 7:100073. [PMID: 35757056 PMCID: PMC9216267 DOI: 10.1016/j.cpnec.2021.100073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 07/22/2021] [Indexed: 12/15/2022] Open
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58
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Henderson GC. Plasma Free Fatty Acid Concentration as a Modifiable Risk Factor for Metabolic Disease. Nutrients 2021; 13:nu13082590. [PMID: 34444750 PMCID: PMC8402049 DOI: 10.3390/nu13082590] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/18/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023] Open
Abstract
Plasma free fatty acid (FFA) concentration is elevated in obesity, insulin resistance (IR), non-alcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D), and related comorbidities such as cardiovascular disease (CVD). Furthermore, experimentally manipulating plasma FFA in the laboratory setting modulates metabolic markers of these disease processes. In this article, evidence is presented indicating that plasma FFA is a disease risk factor. Elevations of plasma FFA can promote ectopic lipid deposition, IR, as well as vascular and cardiac dysfunction. Typically, elevated plasma FFA results from accelerated adipose tissue lipolysis, caused by a high adipose tissue mass, adrenal hormones, or other physiological stressors. Reducing an individual’s postabsorptive and postprandial plasma FFA concentration is expected to improve health. Lifestyle change could provide a significant opportunity for plasma FFA reduction. Various factors can impact plasma FFA concentration, such as chronic restriction of dietary energy intake and weight loss, as well as exercise, sleep quality and quantity, and cigarette smoking. In this review, consideration is given to multiple factors which lead to plasma FFA elevation and subsequent disruption of metabolic health. From considering a variety of medical conditions and lifestyle factors, it becomes clear that plasma FFA concentration is a modifiable risk factor for metabolic disease.
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Affiliation(s)
- Gregory C Henderson
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
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59
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Petkevicius K, Bidault G, Virtue S, Newland SA, Dale M, Dugourd A, Saez-Rodriguez J, Mallat Z, Vidal-Puig A. Macrophage beta2-adrenergic receptor is dispensable for the adipose tissue inflammation and function. Mol Metab 2021; 48:101220. [PMID: 33774223 PMCID: PMC8086137 DOI: 10.1016/j.molmet.2021.101220] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/18/2021] [Accepted: 03/20/2021] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Neuroimmune interactions between the sympathetic nervous system (SNS) and macrophages are required for the homeostasis of multiple tissues, including the adipose tissue. It has been proposed that the SNS maintains adipose tissue macrophages (ATMs) in an anti-inflammatory state via direct norepinephrine (NE) signaling to macrophages. This study aimed to investigate the physiological importance of this paradigm by utilizing a mouse model in which the adrenergic signaling from the SNS to macrophages, but not to other adipose tissue cells, was disrupted. METHODS We generated a macrophage-specific B2AR knockout mouse (Adrb2ΔLyz2) by crossing Adrb2fl/fl and Lyz2Cre/+ mice. We have previously shown that macrophages isolated from Adrb2ΔLyz2 animals do not respond to NE stimulation in vitro. Herein we performed a metabolic phenotyping of Adrb2ΔLyz2 mice on either chow or high-fat diet (HFD). We also assessed the adipose tissue function of Adrb2ΔLyz2 animals during fasting and cold exposure. Finally, we transplanted Adrb2ΔLyz2 bone marrow to low-density lipoprotein receptor (LDLR) knockout mice and investigated the development of atherosclerosis during Western diet feeding. RESULTS We demonstrated that SNS-associated ATMs have a transcriptional profile indicative of activated beta-2 adrenergic receptor (B2AR), the main adrenergic receptor isoform in myeloid cells. However, Adrb2ΔLyz2 mice have unaltered energy balance on a chow or HFD. Furthermore, Adrb2ΔLyz2 mice show similar levels of adipose tissue inflammation and function during feeding, fasting, or cold exposure, and develop insulin resistance during HFD at the same rate as controls. Finally, macrophage-specific B2AR deletion does not affect the development of atherosclerosis on an LDL receptor-null genetic background. CONCLUSIONS Overall, our data suggest that the SNS does not directly modulate the phenotype of adipose tissue macrophages in either lean mice or mouse models of cardiometabolic disease. Instead, sympathetic nerve activity exerts an indirect effect on adipose tissue macrophages through the modulation of adipocyte function.
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MESH Headings
- Adipocytes/metabolism
- Adipose Tissue, White/metabolism
- Animals
- Atherosclerosis/complications
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Bone Marrow Transplantation/methods
- Cells, Cultured
- Diet, High-Fat/adverse effects
- Diet, Western/adverse effects
- Disease Models, Animal
- Female
- Insulin Resistance/genetics
- Macrophages/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Obesity/complications
- Obesity/genetics
- Obesity/metabolism
- Panniculitis/genetics
- Panniculitis/metabolism
- Phenotype
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/genetics
- Sympathetic Nervous System/metabolism
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Affiliation(s)
- Kasparas Petkevicius
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC, Cambridge, United Kingdom.
| | - Guillaume Bidault
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC, Cambridge, United Kingdom
| | - Sam Virtue
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC, Cambridge, United Kingdom
| | - Stephen A Newland
- Division of Cardiovascular Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Martin Dale
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC, Cambridge, United Kingdom
| | - Aurelien Dugourd
- Joint Research Centre for Computational Biomedicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany; Institute for Computational Biomedicine, Heidelberg University, Faculty of Medicine & Heidelberg University Hospital, Heidelberg, Germany
| | - Julio Saez-Rodriguez
- Joint Research Centre for Computational Biomedicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany; Institute for Computational Biomedicine, Heidelberg University, Faculty of Medicine & Heidelberg University Hospital, Heidelberg, Germany
| | - Ziad Mallat
- Division of Cardiovascular Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRC, Cambridge, United Kingdom; Wellcome Trust Sanger Institute, Hinxton, United Kingdom.
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60
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Wang Z, Wang QA, Liu Y, Jiang L. Energy metabolism in brown adipose tissue. FEBS J 2021; 288:3647-3662. [PMID: 34028971 DOI: 10.1111/febs.16015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/06/2021] [Accepted: 05/12/2021] [Indexed: 12/14/2022]
Abstract
Brown adipose tissue (BAT) is well known to burn calories through uncoupled respiration, producing heat to maintain body temperature. This 'calorie wasting' feature makes BAT a special tissue, which can function as an 'energy sink' in mammals. While a combination of high energy intake and low energy expenditure is the leading cause of overweight and obesity in modern society, activating a safe 'energy sink' has been proposed as a promising obesity treatment strategy. Metabolically, lipids and glucose have been viewed as the major energy substrates in BAT, while succinate, lactate, branched-chain amino acids, and other metabolites can also serve as energy substrates for thermogenesis. Since the cataplerotic and anaplerotic reactions of these metabolites interconnect with each other, BAT relies on its dynamic, flexible, and complex metabolism to support its special function. In this review, we summarize how BAT orchestrates the metabolic utilization of various nutrients to support thermogenesis and contributes to whole-body metabolic homeostasis.
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Affiliation(s)
- Zhichao Wang
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, Duarte, CA, USA
| | - Qiong A Wang
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, Duarte, CA, USA.,Comprehensive Cancer Center, Beckman Research Institute, City of Hope Medical Center, Duarte, CA, USA
| | - Yong Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Institute for Advanced Studies, Wuhan University, China
| | - Lei Jiang
- Department of Molecular & Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, Duarte, CA, USA.,Comprehensive Cancer Center, Beckman Research Institute, City of Hope Medical Center, Duarte, CA, USA
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61
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Zebrafish and Flavonoids: Adjuvants against Obesity. Molecules 2021; 26:molecules26103014. [PMID: 34069388 PMCID: PMC8158719 DOI: 10.3390/molecules26103014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 12/16/2022] Open
Abstract
Obesity is a pathological condition, defined as an excessive accumulation of fat, primarily caused by an energy imbalance. The storage of excess energy in the form of triglycerides within the adipocyte leads to lipotoxicity and promotes the phenotypic switch in the M1/M2 macrophage. These changes induce the development of a chronic state of low-grade inflammation, subsequently generating obesity-related complications, commonly known as metabolic syndromes. Over the past decade, obesity has been studied in many animal models. However, due to its competitive aspects and unique characteristics, the use of zebrafish has begun to gain traction in experimental obesity research. To counteract obesity and its related comorbidities, several natural substances have been studied. One of those natural substances reported to have substantial biological effects on obesity are flavonoids. This review summarizes the results of studies that examined the effects of flavonoids on obesity and related diseases and the emergence of zebrafish as a model of diet-induced obesity.
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Morigny P, Boucher J, Arner P, Langin D. Lipid and glucose metabolism in white adipocytes: pathways, dysfunction and therapeutics. Nat Rev Endocrinol 2021; 17:276-295. [PMID: 33627836 DOI: 10.1038/s41574-021-00471-8] [Citation(s) in RCA: 208] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
In mammals, the white adipocyte is a cell type that is specialized for storage of energy (in the form of triacylglycerols) and for energy mobilization (as fatty acids). White adipocyte metabolism confers an essential role to adipose tissue in whole-body homeostasis. Dysfunction in white adipocyte metabolism is a cardinal event in the development of insulin resistance and associated disorders. This Review focuses on our current understanding of lipid and glucose metabolic pathways in the white adipocyte. We survey recent advances in humans on the importance of adipocyte hypertrophy and on the in vivo turnover of adipocytes and stored lipids. At the molecular level, the identification of novel regulators and of the interplay between metabolic pathways explains the fine-tuning between the anabolic and catabolic fates of fatty acids and glucose in different physiological states. We also examine the metabolic alterations involved in the genesis of obesity-associated metabolic disorders, lipodystrophic states, cancers and cancer-associated cachexia. New challenges include defining the heterogeneity of white adipocytes in different anatomical locations throughout the lifespan and investigating the importance of rhythmic processes. Targeting white fat metabolism offers opportunities for improved patient stratification and a wide, yet unexploited, range of therapeutic opportunities.
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Affiliation(s)
- Pauline Morigny
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, Toulouse, France
- University of Toulouse, Paul Sabatier University, I2MC, UMR1297, Toulouse, France
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Jeremie Boucher
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- The Lundberg Laboratory for Diabetes Research, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Peter Arner
- Department of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Dominique Langin
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, Toulouse, France.
- University of Toulouse, Paul Sabatier University, I2MC, UMR1297, Toulouse, France.
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague and Paul Sabatier University, Toulouse, France.
- Toulouse University Hospitals, Laboratory of Clinical Biochemistry, Toulouse, France.
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Pajed L, Taschler U, Tilp A, Hofer P, Kotzbeck P, Kolleritsch S, Radner FPW, Pototschnig I, Wagner C, Schratter M, Eder S, Huetter S, Schreiber R, Haemmerle G, Eichmann TO, Schweiger M, Hoefler G, Kershaw EE, Lass A, Schoiswohl G. Advanced lipodystrophy reverses fatty liver in mice lacking adipocyte hormone-sensitive lipase. Commun Biol 2021; 4:323. [PMID: 33692445 PMCID: PMC7946939 DOI: 10.1038/s42003-021-01858-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 02/16/2021] [Indexed: 11/09/2022] Open
Abstract
Modulation of adipocyte lipolysis represents an attractive approach to treat metabolic diseases. Lipolysis mainly depends on two enzymes: adipose triglyceride lipase and hormone-sensitive lipase (HSL). Here, we investigated the short- and long-term impact of adipocyte HSL on energy homeostasis using adipocyte-specific HSL knockout (AHKO) mice. AHKO mice fed high-fat-diet (HFD) progressively developed lipodystrophy accompanied by excessive hepatic lipid accumulation. The increased hepatic triglyceride deposition was due to induced de novo lipogenesis driven by increased fatty acid release from adipose tissue during refeeding related to defective insulin signaling in adipose tissue. Remarkably, the fatty liver of HFD-fed AHKO mice reversed with advanced age. The reversal of fatty liver coincided with a pronounced lipodystrophic phenotype leading to blunted lipolytic activity in adipose tissue. Overall, we demonstrate that impaired adipocyte HSL-mediated lipolysis affects systemic energy homeostasis in AHKO mice, whereby with older age, these mice reverse their fatty liver despite advanced lipodystrophy.
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Affiliation(s)
- Laura Pajed
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anna Tilp
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Petra Kotzbeck
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | | | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Carina Wagner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Sandra Eder
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Sabrina Huetter
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- Center for Explorative Lipidomics, BioTechMed-Graz, Graz, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerald Hoefler
- Diagnostic & Research Institute of Pathology, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Erin E Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Gabriele Schoiswohl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- Department of Pharmacology and Toxicology, University of Graz, Graz, Austria.
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Cooper PO, Haas MR, Noonepalle SKR, Shook BA. Dermal Drivers of Injury-Induced Inflammation: Contribution of Adipocytes and Fibroblasts. Int J Mol Sci 2021; 22:1933. [PMID: 33669239 PMCID: PMC7919834 DOI: 10.3390/ijms22041933] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 02/07/2023] Open
Abstract
Irregular inflammatory responses are a major contributor to tissue dysfunction and inefficient repair. Skin has proven to be a powerful model to study mechanisms that regulate inflammation. In particular, skin wound healing is dependent on a rapid, robust immune response and subsequent dampening of inflammatory signaling. While injury-induced inflammation has historically been attributed to keratinocytes and immune cells, a vast body of evidence supports the ability of non-immune cells to coordinate inflammation in numerous tissues and diseases. In this review, we concentrate on the active participation of tissue-resident adipocytes and fibroblasts in pro-inflammatory signaling after injury, and how altered cellular communication from these cells can contribute to irregular inflammation associated with aberrant wound healing. Furthering our understanding of how tissue-resident mesenchymal cells contribute to inflammation will likely reveal new targets that can be manipulated to regulate inflammation and repair.
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Affiliation(s)
| | | | | | - Brett A. Shook
- Department of Biochemistry and Molecular Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.O.C.); (M.R.H.); (S.k.R.N.)
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Han SL, Liu Y, Limbu SM, Chen LQ, Zhang ML, Du ZY. The reduction of lipid-sourced energy production caused by ATGL inhibition cannot be compensated by activation of HSL, autophagy, and utilization of other nutrients in fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:173-188. [PMID: 33245450 DOI: 10.1007/s10695-020-00904-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/18/2020] [Indexed: 06/11/2023]
Abstract
The adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL)-mediated lipolysis play important roles in lipid catabolism. ATGL is considered the central rate-limiting enzyme in the mobilization of fatty acids in mammals. Currently, severe fat accumulation has been commonly detected in farmed fish globally. However, the ATGL-mediated lipolysis and the potential synergy among ATGL, HSL, and autophagy, which is another way for lipid breakdown, have not been intensively understood in fish. In the present study, we added Atglistatin as an ATGL-specific inhibitor into the zebrafish diet and fed to the fish for 5 weeks. The results showed that the Atglistatin-treated fish exhibited severe fat deposition, reduced oxygen consumption, and fatty acid β-oxidation, accompanied with increased oxidative stress and inflammation. Furthermore, the Atglistatin-treated fish elevated total and phosphorylation protein expressions of HSL. However, the free fatty acids and lipase activities in organs were still systemically reduced in the Atglistatin-treated fish, and the autophagy marker LC3 was also decreased in the liver. On the other hand, glycogenolysis was stimulated but blood glucose was higher in the Atglistatin-treated fish. The transcriptomic analysis also provided the hint that the protein turnover efficiency in Atglistatin-treated fish was likely to be accelerated, but the protein content in whole fish was not affected. Taken together, ATGL plays crucial roles in energy homeostasis such that its inhibition causes loss of lipid-sourced energy production, which cannot be compensated by activation of HSL, autophagy, and utilization of other nutrients.
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Affiliation(s)
- Si-Lan Han
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Yan Liu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Samwel M Limbu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
- Department of Aquatic Sciences and Fisheries Technology, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
- ECNU-UDSM Joint Research Center for Aquaculture and Fish Biology (JRCAFB), Dar es Salaam, Tanzania
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China.
- ECNU-UDSM Joint Research Center for Aquaculture and Fish Biology (JRCAFB), Shanghai, China.
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66
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Expression Signatures of microRNAs and Their Targeted Pathways in the Adipose Tissue of Chickens during the Transition from Embryonic to Post-Hatch Development. Genes (Basel) 2021; 12:genes12020196. [PMID: 33572831 PMCID: PMC7911735 DOI: 10.3390/genes12020196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 12/21/2022] Open
Abstract
As the chick transitions from embryonic to post-hatching life, its metabolism must quickly undergo a dramatic switch in its major energy source. The chick embryo derives most of its energy from the yolk, a lipid-rich/carbohydrate-poor source. Upon hatching, the chick’s metabolism must then be able to utilize a lipid-poor/carbohydrate-rich source (feed) as its main form of energy. We recently found that a number of hepatically-expressed microRNAs (miRNAs) help facilitate this shift in metabolic processes in the chick liver, the main site of lipogenesis. While adipose tissue was initially thought to mainly serve as a lipid storage site, it is now known to carry many metabolic, endocrine, and immunological functions. Therefore, it would be expected that adipose tissue is also an important factor in the metabolic switch. To that end, we used next generation sequencing (NGS) and real-time quantitative PCR (RT-qPCR) to generate miRNome and transcriptome signatures of the adipose tissue during the transition from late embryonic to early post-hatch development. As adipose tissue is well known to produce inflammatory and other immune factors, we used SPF white leghorns to generate the initial miRNome and transcriptome signatures to minimize complications from external factors (e.g., pathogenic infections) and ensure the identification of bona fide switch-associated miRNAs and transcripts. We then examined their expression signatures in the adipose tissue of broilers (Ross 708). Using E18 embryos as representative of pre-switching metabolism and D3 chicks as a representative of post-switching metabolism, we identified a group of miRNAs which work concordantly to regulate a diverse but interconnected group of developmental, immune and metabolic processes in the adipose tissue during the metabolic switch. Network mapping suggests that during the first days post-hatch, despite the consumption of feed, the chick is still heavily reliant upon adipose tissue lipid stores for energy production, and is not yet efficiently using their new energy source for de novo lipid storage. A number of core master regulatory pathways including, circadian rhythm transcriptional regulation and growth hormone (GH) signaling, likely work in concert with miRNAs to maintain an essential balance between adipogenic, lipolytic, developmental, and immunological processes in the adipose tissue during the metabolic switch.
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67
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ATGL activity regulates GLUT1-mediated glucose uptake and lactate production via TXNIP stability in adipocytes. J Biol Chem 2021; 296:100332. [PMID: 33508319 PMCID: PMC7949114 DOI: 10.1016/j.jbc.2021.100332] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 01/16/2021] [Accepted: 01/22/2021] [Indexed: 01/03/2023] Open
Abstract
Traditionally, lipolysis has been regarded as an enzymatic activity that liberates fatty acids as metabolic fuel. However, recent work has shown that novel substrates, including a variety of lipid compounds such as fatty acids and their derivatives, release lipolysis products that act as signaling molecules and transcriptional modulators. While these studies have expanded the role of lipolysis, the mechanisms underpinning lipolysis signaling are not fully defined. Here, we uncover a new mechanism regulating glucose uptake, whereby activation of lipolysis, in response to elevated cAMP, leads to the stimulation of thioredoxin-interacting protein (TXNIP) degradation. This, in turn, selectively induces glucose transporter 1 surface localization and glucose uptake in 3T3-L1 adipocytes and increases lactate production. Interestingly, cAMP-induced glucose uptake via degradation of TXNIP is largely dependent upon adipose triglyceride lipase (ATGL) and not hormone-sensitive lipase or monoacylglycerol lipase. Pharmacological inhibition or knockdown of ATGL alone prevents cAMP-dependent TXNIP degradation and thus significantly decreases glucose uptake and lactate secretion. Conversely, overexpression of ATGL amplifies the cAMP response, yielding increased glucose uptake and lactate production. Similarly, knockdown of TXNIP elicits enhanced basal glucose uptake and lactate secretion, and increased cAMP further amplifies this phenotype. Overexpression of TXNIP reduces basal and cAMP-stimulated glucose uptake and lactate secretion. As a proof of concept, we replicated these findings in human primary adipocytes and observed TXNIP degradation and increased glucose uptake and lactate secretion upon elevated cAMP signaling. Taken together, our results suggest a crosstalk between ATGL-mediated lipolysis and glucose uptake.
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68
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Lou P, Bi X, Tian Y, Li G, Kang Q, Lv C, Song Y, Xu J, Sheng X, Yang X, Liu R, Meng Q, Ren F, Plikus MV, Liang B, Zhang B, Guo H, Yu Z. MiR-22 modulates brown adipocyte thermogenesis by synergistically activating the glycolytic and mTORC1 signaling pathways. Am J Cancer Res 2021; 11:3607-3623. [PMID: 33664851 PMCID: PMC7914365 DOI: 10.7150/thno.50900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022] Open
Abstract
Background: Brown adipose tissue (BAT) dissipates chemical energy as heat and has the potential to be a protective strategy to prevent obesity. microRNAs (miRNAs) are emerging as important posttranscriptional factors affecting the thermogenic function of BAT. However, the regulatory mechanism underlying miRNA-mediated energy metabolism in BAT is not fully understood. Here, we explored the roles of miR-22 in BAT thermogenesis and energy metabolism. Methods: Using global and conditional knockout mice as in vivo models and primary brown adipocytes as an in vitro system, we investigated the function of miR-22 in BAT thermogenesis in vivo and in vitro. Results: miR-22 expression was upregulated in BAT in response to cold exposure and during brown preadipocyte differentiation. Both global and conditional knockout mice displayed BAT whitening, impaired cold tolerance, and decreased BAT thermogenesis. Moreover, we found that miR-22 deficiency impaired BAT glycolytic capacity, which is critical for thermogenesis. The mechanistic results revealed that miR-22 activated the mTORC1 signaling pathway by directly suppressing Tsc1 and concomitantly directly suppressing Hif1an, an inhibitor of Hif1α, which promotes glycolysis and maintains thermogenesis. Conclusions: Our findings identify miR-22 as a critical regulator in the control of thermogenesis in BAT and as a potential therapeutic target for human metabolic disorders.
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69
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Selen ES, Choi J, Wolfgang MJ. Discordant hepatic fatty acid oxidation and triglyceride hydrolysis leads to liver disease. JCI Insight 2021; 6:135626. [PMID: 33491665 PMCID: PMC7934875 DOI: 10.1172/jci.insight.135626] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
To extract energy from stored lipids, fatty acids must first be liberated from triglyceride before their β-oxidation in mitochondria in a coordinated and stepwise manner. To determine the independent and interdependent roles of hepatic triglyceride hydrolysis and fatty acid oxidation, mice were generated with a liver-specific defect in triglyceride hydrolysis (AtglL–/–), fatty acid oxidation (Cpt2L–/–), or both (double knockout). The loss of either gene resulted in the compensatory increase in the other, demonstrating their coordination. The loss of individual components of fatty acid catabolism (carnitine palmitoyl transferase 2 [Cpt2], adipose triglyceride lipase [Atgl], and Pparα) resulted in largely independent effects on hepatocyte morphology, intermediary metabolism, and gene expression in response to fasting. However, high-fat feeding revealed the interdependent role of Atgl and Cpt2, as the loss of only one of the genes resulted in steatosis (fatty liver) but the loss of both components resulted in significant steatohepatitis (inflammation and fibrosis). Lipolysis and β-oxidation are intimately linked within a continuous pathway, and disruption of their coordination leads to unique cellular and molecular phenotypes that ultimately result in liver disease.
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Affiliation(s)
| | | | - Michael J Wolfgang
- Department of Biological Chemistry and.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Takahara S, Ferdaoussi M, Srnic N, Maayah ZH, Soni S, Migglautsch AK, Breinbauer R, Kershaw EE, Dyck JRB. Inhibition of ATGL in adipose tissue ameliorates isoproterenol-induced cardiac remodeling by reducing adipose tissue inflammation. Am J Physiol Heart Circ Physiol 2021; 320:H432-H446. [PMID: 33185110 PMCID: PMC7847076 DOI: 10.1152/ajpheart.00737.2020] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023]
Abstract
Following cardiac injury, increased adrenergic drive plays an important role in compensating for reduced cardiac function. However, chronic excess adrenergic stimulation can be detrimental to cardiac pathophysiology and can also affect other organs including adipose tissue, leading to increased lipolysis. Interestingly, inhibition of adipose triglyceride lipase (ATGL), a rate-limiting enzyme in lipolysis, in adipocytes ameliorates cardiac dysfunction in a heart failure model. Thus, we investigated whether inhibition of adipocyte ATGL can mitigate the adverse cardiac effects of chronic adrenergic stimulation and explored the underlying mechanisms. To do this, isoproterenol (ISO) was continuously administered to C57Bl/6N mice for 2 wk with or without an ATGL inhibitor (Atglistatin). We found that Atglistatin alleviated ISO-induced cardiac remodeling and reduced ISO-induced upregulation of galectin-3, a marker of activated macrophages and a potent inducer of fibrosis, in white adipose tissue (WAT), heart, and the circulation. To test whether the beneficial effects of Atglistatin occur via inhibition of adipocyte ATGL, adipocyte-specific ATGL knockout (atATGL-KO) mice were utilized for similar experiments. Subsequently, the same cardioprotective effects of atATGL-KO following ISO administration were observed. Furthermore, Atglistatin and atATGL-KO abolished ISO-induced galectin-3 secretion from excised WAT. We further demonstrated that activation of cardiac fibroblasts by the conditioned media of ISO-stimulated WAT is galectin-3-dependent. In conclusion, the inhibition of adipocyte ATGL ameliorated ISO-induced cardiac remodeling possibly by reducing galectin-3 secretion from adipose tissue. Thus, inhibition of adipocyte ATGL might be a potential target to prevent some of the adverse effects of chronic excess adrenergic drive.NEW & NOTEWORTHY The reduction of lipolysis by adipocyte ATGL inhibition ameliorates cardiac remodeling induced by chronic β-adrenergic stimulation likely via reducing galectin-3 secretion from adipose tissue. Our findings highlight that suppressing lipolysis in adipocytes may be a potential therapeutic target for patients with heart failure whose sympathetic nervous system is activated. Furthermore, galectin-3 might be involved in the mechanisms by which excessive lipolysis in adipose tissues influences remote cardiac pathologies and thus warrants further investigation.
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Affiliation(s)
- Shingo Takahara
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mourad Ferdaoussi
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Nikola Srnic
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Zaid H Maayah
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Shubham Soni
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Anna K Migglautsch
- Institute of Organic Chemistry, Graz University of Technology, Graz, Austria
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, Graz, Austria
| | - Erin E Kershaw
- Division of Endocrinology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jason R B Dyck
- Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
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de Oliveira C, Khatua B, Noel P, Kostenko S, Bag A, Balakrishnan B, Patel KS, Guerra AA, Martinez MN, Trivedi S, McCullough A, Lam-Himlin DM, Navina S, Faigel DO, Fukami N, Pannala R, Phillips AE, Papachristou GI, Kershaw EE, Lowe ME, Singh VP. Pancreatic triglyceride lipase mediates lipotoxic systemic inflammation. J Clin Invest 2020; 130:1931-1947. [PMID: 31917686 DOI: 10.1172/jci132767] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022] Open
Abstract
Visceral adipose tissue plays a critical role in numerous diseases. Although imaging studies often show adipose involvement in abdominal diseases, their outcomes may vary from being a mild self-limited illness to one with systemic inflammation and organ failure. We therefore compared the pattern of visceral adipose injury during acute pancreatitis and acute diverticulitis to determine its role in organ failure. Acute pancreatitis-associated adipose tissue had ongoing lipolysis in the absence of adipocyte triglyceride lipase (ATGL). Pancreatic lipase injected into mouse visceral adipose tissue hydrolyzed adipose triglyceride and generated excess nonesterified fatty acids (NEFAs), which caused organ failure in the absence of acute pancreatitis. Pancreatic triglyceride lipase (PNLIP) increased in adipose tissue during pancreatitis and entered adipocytes by multiple mechanisms, hydrolyzing adipose triglyceride and generating excess NEFAs. During pancreatitis, obese PNLIP-knockout mice, unlike obese adipocyte-specific ATGL knockouts, had lower visceral adipose tissue lipolysis, milder inflammation, less severe organ failure, and improved survival. PNLIP-knockout mice, unlike ATGL knockouts, were protected from adipocyte-induced pancreatic acinar injury without affecting NEFA signaling or acute pancreatitis induction. Therefore, during pancreatitis, unlike diverticulitis, PNLIP leaking into visceral adipose tissue can cause excessive visceral adipose tissue lipolysis independently of adipocyte-autonomous ATGL, and thereby worsen organ failure.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Ann McCullough
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona, USA
| | - Dora M Lam-Himlin
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona, USA
| | | | | | | | | | - Anna Evans Phillips
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Erin E Kershaw
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mark E Lowe
- Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri, USA
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Raje V, Ahern KW, Martinez BA, Howell NL, Oenarto V, Granade ME, Kim JW, Tundup S, Bottermann K, Gödecke A, Keller SR, Kadl A, Bland ML, Harris TE. Adipocyte lipolysis drives acute stress-induced insulin resistance. Sci Rep 2020; 10:18166. [PMID: 33097799 PMCID: PMC7584576 DOI: 10.1038/s41598-020-75321-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
Stress hyperglycemia and insulin resistance are evolutionarily conserved metabolic adaptations to severe injury including major trauma, burns, or hemorrhagic shock (HS). In response to injury, the neuroendocrine system increases secretion of counterregulatory hormones that promote rapid mobilization of nutrient stores, impair insulin action, and ultimately cause hyperglycemia, a condition known to impair recovery from injury in the clinical setting. We investigated the contributions of adipocyte lipolysis to the metabolic response to acute stress. Both surgical injury with HS and counterregulatory hormone (epinephrine) infusion profoundly stimulated adipocyte lipolysis and simultaneously triggered insulin resistance and hyperglycemia. When lipolysis was inhibited, the stress-induced insulin resistance and hyperglycemia were largely abolished demonstrating an essential requirement for adipocyte lipolysis in promoting stress-induced insulin resistance. Interestingly, circulating non-esterified fatty acid levels did not increase with lipolysis or correlate with insulin resistance during acute stress. Instead, we show that impaired insulin sensitivity correlated with circulating levels of the adipokine resistin in a lipolysis-dependent manner. Our findings demonstrate the central importance of adipocyte lipolysis in the metabolic response to injury. This insight suggests new approaches to prevent insulin resistance and stress hyperglycemia in trauma and surgery patients and thereby improve outcomes.
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Affiliation(s)
- Vidisha Raje
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Katelyn W Ahern
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Brittany A Martinez
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Nancy L Howell
- Department of Medicine, Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - Vici Oenarto
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,Institute of Cardiovascular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Mitchell E Granade
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Jae Woo Kim
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Smanla Tundup
- Department of Medicine, Pulmonary and Critical Care Medicine, University of Virginia, Charlottesville, VA, USA
| | | | - Axel Gödecke
- Institute of Cardiovascular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Susanna R Keller
- Department of Medicine, Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - Alexandra Kadl
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,Department of Medicine, Pulmonary and Critical Care Medicine, University of Virginia, Charlottesville, VA, USA
| | - Michelle L Bland
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.
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73
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Adipocyte lipolysis: from molecular mechanisms of regulation to disease and therapeutics. Biochem J 2020; 477:985-1008. [PMID: 32168372 DOI: 10.1042/bcj20190468] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 12/20/2022]
Abstract
Fatty acids (FAs) are stored safely in the form of triacylglycerol (TAG) in lipid droplet (LD) organelles by professional storage cells called adipocytes. These lipids are mobilized during adipocyte lipolysis, the fundamental process of hydrolyzing TAG to FAs for internal or systemic energy use. Our understanding of adipocyte lipolysis has greatly increased over the past 50 years from a basic enzymatic process to a dynamic regulatory one, involving the assembly and disassembly of protein complexes on the surface of LDs. These dynamic interactions are regulated by hormonal signals such as catecholamines and insulin which have opposing effects on lipolysis. Upon stimulation, patatin-like phospholipase domain containing 2 (PNPLA2)/adipocyte triglyceride lipase (ATGL), the rate limiting enzyme for TAG hydrolysis, is activated by the interaction with its co-activator, alpha/beta hydrolase domain-containing protein 5 (ABHD5), which is normally bound to perilipin 1 (PLIN1). Recently identified negative regulators of lipolysis include G0/G1 switch gene 2 (G0S2) and PNPLA3 which interact with PNPLA2 and ABHD5, respectively. This review focuses on the dynamic protein-protein interactions involved in lipolysis and discusses some of the emerging concepts in the control of lipolysis that include allosteric regulation and protein turnover. Furthermore, recent research demonstrates that many of the proteins involved in adipocyte lipolysis are multifunctional enzymes and that lipolysis can mediate homeostatic metabolic signals at both the cellular and whole-body level to promote inter-organ communication. Finally, adipocyte lipolysis is involved in various diseases such as cancer, type 2 diabetes and fatty liver disease, and targeting adipocyte lipolysis is of therapeutic interest.
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74
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Prolonged fasting drives a program of metabolic inflammation in human adipose tissue. Mol Metab 2020; 42:101082. [PMID: 32992039 PMCID: PMC7554650 DOI: 10.1016/j.molmet.2020.101082] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/06/2020] [Accepted: 09/14/2020] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE The human adaptive fasting response enables survival during periods of caloric deprivation. A crucial component of the fasting response is the shift from glucose metabolism to utilization of lipids, underscoring the importance of adipose tissue as the central lipid-storing organ. The objective of this study was to investigate the response of adipose tissue to a prolonged fast in humans. METHODS We performed RNA sequencing of subcutaneous adipose tissue samples longitudinally collected during a 10-day, 0-calorie fast in humans. We further investigated observed transcriptional signatures utilizing cultured human monocytes and Thp1 cells. We examined the cellularity of adipose tissue biopsies with transmission electron microscopy and tested for associated changes in relevant inflammatory mediators in the systemic circulation by ELISA assays of longitudinally collected blood samples. RESULTS Coincident with the expected shift away from glucose utilization and lipid storage, we demonstrated downregulation of pathways related to glycolysis, oxidative phosphorylation, and lipogenesis. The canonical lipolysis pathway was also downregulated, whereas fasting drove alternative lysosomal paths to lipid digestion. Unexpectedly, the dominant induced pathways were associated with immunity and inflammation, although this only became evident at the 10-day time point. Among the most augmented transcripts were those associated with macrophage identity and function, such as members of the erythroblast transformation-specific (ETS) transcription factor family. Key components of the macrophage transcriptional signal in fasting adipose tissue were recapitulated with induced expression of two of the ETS transcription factors via cultured macrophages, SPIC and SPI1. The inflammatory signal was further reflected by an increase in systemic inflammatory mediators. CONCLUSIONS Collectively, this study demonstrates an unexpected role of metabolic inflammation in the human adaptive fasting response.
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75
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Mayer N, Schweiger M, Fuchs E, Migglautsch AK, Doler C, Grabner GF, Romauch M, Melcher MC, Zechner R, Zimmermann R, Breinbauer R. Structure-activity relationship studies for the development of inhibitors of murine adipose triglyceride lipase (ATGL). Bioorg Med Chem 2020; 28:115610. [PMID: 32690265 DOI: 10.1016/j.bmc.2020.115610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 01/20/2023]
Abstract
High serum fatty acid (FA) levels are causally linked to the development of insulin resistance, which eventually progresses to type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) generalized in the term metabolic syndrome. Adipose triglyceride lipase (ATGL) is the initial enzyme in the hydrolysis of intracellular triacylglycerol (TG) stores, liberating fatty acids that are released from adipocytes into the circulation. Hence, ATGL-specific inhibitors have the potential to lower circulating FA concentrations, and counteract the development of insulin resistance and NAFLD. In this article, we report about structure-activity relationship (SAR) studies of small molecule inhibitors of murine ATGL which led to the development of Atglistatin. Atglistatin is a specific inhibitor of murine ATGL, which has proven useful for the validation of ATGL as a potential drug target.
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Affiliation(s)
- Nicole Mayer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31, A-8010 Graz, Austria; BIOTECHMED Graz, A-8010, Austria
| | - Elisabeth Fuchs
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Anna K Migglautsch
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Carina Doler
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31, A-8010 Graz, Austria
| | - Matthias Romauch
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31, A-8010 Graz, Austria
| | | | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31, A-8010 Graz, Austria; BIOTECHMED Graz, A-8010, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31, A-8010 Graz, Austria; BIOTECHMED Graz, A-8010, Austria.
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria; BIOTECHMED Graz, A-8010, Austria.
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76
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Dahik VD, Frisdal E, Le Goff W. Rewiring of Lipid Metabolism in Adipose Tissue Macrophages in Obesity: Impact on Insulin Resistance and Type 2 Diabetes. Int J Mol Sci 2020; 21:ijms21155505. [PMID: 32752107 PMCID: PMC7432680 DOI: 10.3390/ijms21155505] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 12/12/2022] Open
Abstract
Obesity and its two major comorbidities, insulin resistance and type 2 diabetes, represent worldwide health issues whose incidence is predicted to steadily rise in the coming years. Obesity is characterized by an accumulation of fat in metabolic tissues resulting in chronic inflammation. It is now largely accepted that adipose tissue inflammation underlies the etiology of these disorders. Adipose tissue macrophages (ATMs) represent the most enriched immune fraction in hypertrophic, chronically inflamed adipose tissue, and these cells play a key role in diet-induced type 2 diabetes and insulin resistance. ATMs are triggered by the continuous influx of dietary lipids, among other stimuli; however, how these lipids metabolically activate ATM depends on their nature, composition and localization. This review will discuss the fate and molecular programs elicited within obese ATMs by both exogenous and endogenous lipids, as they mediate the inflammatory response and promote or hamper the development of obesity-associated insulin resistance and type 2 diabetes.
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77
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Reinisch I, Schreiber R, Prokesch A. Regulation of thermogenic adipocytes during fasting and cold. Mol Cell Endocrinol 2020; 512:110869. [PMID: 32439414 DOI: 10.1016/j.mce.2020.110869] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022]
Abstract
Cold exposure activates brown and brown-like adipocytes that dissipate large amounts of glucose and fatty acids via uncoupling protein 1 (UCP1) to drive non-shivering thermogenesis (NST). Evidence for the existence of these thermogenic adipocytes in adult humans gave rise to a renaissance in research on brown adipose tissue, establishing it as linchpin of energy homeostasis and metabolic health. Besides low ambient temperature, shortage or excess of food affect thermoregulation. Upon high caloric meals thermogenic adipocytes burn excess calories and maintain energy balance. In contrast, in conditions of nutrient deprivation, counter-regulatory mechanisms prevent thermogenic adipocytes from "wasting" energy substrates that need to be conserved. In this review, we discuss cell-autonomous mechanisms, metabolites, and hormones that modify NST in response to nutrient fluctuations. In particular, we focus on how thermogenic adipocytes balance thermogenesis with systemic energy homeostasis during fasting periods.
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Affiliation(s)
- Isabel Reinisch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
| | - Andreas Prokesch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria; BioTechMed-Graz, 8010, Graz, Austria.
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78
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Wang X, Xu M, Peng Y, Naren Q, Xu Y, Wang X, Yang G, Shi X, Li X. Triptolide enhances lipolysis of adipocytes by enhancing ATGL transcription via upregulation of p53. Phytother Res 2020; 34:3298-3310. [PMID: 32614500 DOI: 10.1002/ptr.6779] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/17/2020] [Accepted: 05/28/2020] [Indexed: 12/17/2022]
Abstract
Lipolysis is an essential physiological activity of adipocytes. The Patatin Like Phospholipase Domain Containing 2 (PNPLA2) gene encodes the enzyme adipose triglyceride lipase (ATGL) responsible for triglyceride hydrolysis, the first step in lipolysis. In this study, we investigated the potential of triptolide (TP), a natural plant extract, to induce weight loss by examining its effect on ATGL expression. We found that long- and short-term TP administration reduced body weight and fat weight and increased heat production in brown adipose tissue in wild-type C57BL/6 mice. In 3T3-L1 fibroblasts and porcine adipocytes, TP treatment reduced the number of lipid droplets as determined by Oil Red O and BODIPY staining, with concomitant increases in free fatty acid and triglyceride levels in the culture medium. Combined treatment with TP and p53 inhibitor reversed these lipolytic effects. We next amplified the ATGL promoter region and identified conserved p53 binding sites in the sequence by in silico analysis. The results of the dual-luciferase reporter assay using a construct containing the ATGL promoter harboring the p53 binding site showed that p53 induces ATGL promoter activity and consequently, ATGL transcription. These results demonstrate that TP has therapeutic value as an anti-obesity agent and acts by promoting lipolysis via upregulation of p53 and ATGL transcription.
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Affiliation(s)
- Xiaoyu Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Meixue Xu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Ying Peng
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Qimuge Naren
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Yanting Xu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Xin Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Gongshe Yang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Xin'E Shi
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
| | - Xiao Li
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China
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79
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OGT suppresses S6K1-mediated macrophage inflammation and metabolic disturbance. Proc Natl Acad Sci U S A 2020; 117:16616-16625. [PMID: 32601203 DOI: 10.1073/pnas.1916121117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Enhanced inflammation is believed to contribute to overnutrition-induced metabolic disturbance. Nutrient flux has also been shown to be essential for immune cell activation. Here, we report an unexpected role of nutrient-sensing O-linked β-N-acetylglucosamine (O-GlcNAc) signaling in suppressing macrophage proinflammatory activation and preventing diet-induced metabolic dysfunction. Overnutrition stimulates an increase in O-GlcNAc signaling in macrophages. O-GlcNAc signaling is down-regulated during macrophage proinflammatory activation. Suppressing O-GlcNAc signaling by O-GlcNAc transferase (OGT) knockout enhances macrophage proinflammatory polarization, promotes adipose tissue inflammation and lipolysis, increases lipid accumulation in peripheral tissues, and exacerbates tissue-specific and whole-body insulin resistance in high-fat-diet-induced obese mice. OGT inhibits macrophage proinflammatory activation by catalyzing ribosomal protein S6 kinase beta-1 (S6K1) O-GlcNAcylation and suppressing S6K1 phosphorylation and mTORC1 signaling. These findings thus identify macrophage O-GlcNAc signaling as a homeostatic mechanism maintaining whole-body metabolism under overnutrition.
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80
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Shook BA, Wasko RR, Mano O, Rutenberg-Schoenberg M, Rudolph MC, Zirak B, Rivera-Gonzalez GC, López-Giráldez F, Zarini S, Rezza A, Clark DA, Rendl M, Rosenblum MD, Gerstein MB, Horsley V. Dermal Adipocyte Lipolysis and Myofibroblast Conversion Are Required for Efficient Skin Repair. Cell Stem Cell 2020; 26:880-895.e6. [PMID: 32302523 PMCID: PMC7853423 DOI: 10.1016/j.stem.2020.03.013] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 11/20/2019] [Accepted: 03/18/2020] [Indexed: 12/26/2022]
Abstract
Mature adipocytes store fatty acids and are a common component of tissue stroma. Adipocyte function in regulating bone marrow, skin, muscle, and mammary gland biology is emerging, but the role of adipocyte-derived lipids in tissue homeostasis and repair is poorly understood. Here, we identify an essential role for adipocyte lipolysis in regulating inflammation and repair after injury in skin. Genetic mouse studies revealed that dermal adipocytes are necessary to initiate inflammation after injury and promote subsequent repair. We find through histological, ultrastructural, lipidomic, and genetic experiments in mice that adipocytes adjacent to skin injury initiate lipid release necessary for macrophage inflammation. Tamoxifen-inducible genetic lineage tracing of mature adipocytes and single-cell RNA sequencing revealed that dermal adipocytes alter their fate and generate ECM-producing myofibroblasts within wounds. Thus, adipocytes regulate multiple aspects of repair and may be therapeutic for inflammatory diseases and defective wound healing associated with aging and diabetes.
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Affiliation(s)
- Brett A Shook
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Renee R Wasko
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Omer Mano
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Michael Rutenberg-Schoenberg
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Michael C Rudolph
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado, Denver Anschutz Medical Campus, CO 80045, USA
| | - Bahar Zirak
- Department of Dermatology, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | - Simona Zarini
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Amélie Rezza
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 11766, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 11766, USA
| | - Damon A Clark
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Michael Rendl
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 11766, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 11766, USA
| | - Michael D Rosenblum
- Department of Dermatology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mark B Gerstein
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Valerie Horsley
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Department of Dermatology, Yale University, New Haven, CT 06511, USA.
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81
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Yvan-Charvet L, Ivanov S. Metabolic Reprogramming of Macrophages in Atherosclerosis: Is It All about Cholesterol? J Lipid Atheroscler 2020; 9:231-242. [PMID: 32821733 PMCID: PMC7379089 DOI: 10.12997/jla.2020.9.2.231] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/16/2020] [Accepted: 02/11/2020] [Indexed: 12/20/2022] Open
Abstract
Hypercholesterolemia contributes to the chronic inflammatory response during the progression of atherosclerosis, in part by favoring cholesterol loading in macrophages and other immune cells. However, macrophages encounter a substantial amount of other lipids and nutrients after ingesting atherogenic lipoprotein particles or clearing apoptotic cells, increasing their metabolic load and impacting their behavior during atherosclerosis plaque progression. This review examines whether and how fatty acids and glucose shape the cellular metabolic reprogramming of macrophages in atherosclerosis to modulate the onset phase of inflammation and the later resolution stage, in which the balance is tipped toward tissue repair.
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Affiliation(s)
- Laurent Yvan-Charvet
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France
| | - Stoyan Ivanov
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France
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82
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Czech MP. Mechanisms of insulin resistance related to white, beige, and brown adipocytes. Mol Metab 2020; 34:27-42. [PMID: 32180558 PMCID: PMC6997501 DOI: 10.1016/j.molmet.2019.12.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The diminished glucose lowering effect of insulin in obesity, called "insulin resistance," is associated with glucose intolerance, type 2 diabetes, and other serious maladies. Many publications on this topic have suggested numerous hypotheses on the molecular and cellular disruptions that contribute to the syndrome. However, significant uncertainty remains on the mechanisms of its initiation and long-term maintenance. SCOPE OF REVIEW To simplify insulin resistance analysis, this review focuses on the unifying concept that adipose tissue is a central regulator of systemic glucose homeostasis by controlling liver and skeletal muscle metabolism. Key aspects of adipose function related to insulin resistance reviewed are: 1) the modes by which specific adipose tissues control hepatic glucose output and systemic glucose disposal, 2) recently acquired understanding of the underlying mechanisms of these modes of regulation, and 3) the steps in these pathways adversely affected by obesity that cause insulin resistance. MAJOR CONCLUSIONS Adipocyte heterogeneity is required to mediate the multiple pathways that control systemic glucose tolerance. White adipocytes specialize in sequestering triglycerides away from the liver, muscle, and other tissues to limit toxicity. In contrast, brown/beige adipocytes are very active in directly taking up glucose in response to β adrenergic signaling and insulin and enhancing energy expenditure. Nonetheless, white, beige, and brown adipocytes all share the common feature of secreting factors and possibly exosomes that act on distant tissues to control glucose homeostasis. Obesity exerts deleterious effects on each of these adipocyte functions to cause insulin resistance.
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Affiliation(s)
- Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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83
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Kintscher U, Foryst-Ludwig A, Haemmerle G, Zechner R. The Role of Adipose Triglyceride Lipase and Cytosolic Lipolysis in Cardiac Function and Heart Failure. CELL REPORTS MEDICINE 2020; 1:100001. [PMID: 33205054 PMCID: PMC7659492 DOI: 10.1016/j.xcrm.2020.100001] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Heart failure is one of the leading causes of death worldwide. New therapeutic concepts are urgently required to lower the burden of heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), the two major forms of heart failure. Lipolytic processes are induced during the development of heart failure and occur in adipose tissue and multiple organs, including the heart. Increasing evidence suggests that cellular lipolysis, in particular, adipose triglyceride lipase (ATGL) activity, has an important function in cardiac (patho)physiology. This review summarizes the crucial role of cellular lipolysis for normal cardiac function and for the development of HFrEF and HFpEF. We discuss the most relevant pre-clinical studies and elaborate on the cardiac consequences of non-myocardial and myocardial lipolysis modulation. Finally, we critically analyze the therapeutic importance of pharmacological ATGL inhibition as a potential treatment option for HFrEF and/or HFpEF in the future.
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Affiliation(s)
- Ulrich Kintscher
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Pharmacology, Center for Cardiovascular Research, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
- Corresponding author
| | - Anna Foryst-Ludwig
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Pharmacology, Center for Cardiovascular Research, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Einstein BIH Visiting Fellow, Berlin Institute of Health, and Charité - Universitätsmedizin Berlin, Berlin, Germany
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84
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The adrenergic-induced ERK3 pathway drives lipolysis and suppresses energy dissipation. Genes Dev 2020; 34:495-510. [PMID: 32139423 PMCID: PMC7111262 DOI: 10.1101/gad.333617.119] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/11/2020] [Indexed: 02/07/2023]
Abstract
In this study, El-Merahbi et al. investigated new regulators of lipolysis, and using a high-throughput screen identified the extracellular-regulated kinase 3 (ERK3) in lipolysis regulation. They identified a downstream target of the ERK3/MK5 pathway, the transcription factor FOXO1, which promotes expression of the major lipolytic enzyme ATGL, and provide evidence that targeted deletion of ERK3 in mouse adipocytes inhibits lipolysis. Obesity-induced diabetes affects >400 million people worldwide. Uncontrolled lipolysis (free fatty acid release from adipocytes) can contribute to diabetes and obesity. To identify future therapeutic avenues targeting this pathway, we performed a high-throughput screen and identified the extracellular-regulated kinase 3 (ERK3) as a hit. We demonstrated that β-adrenergic stimulation stabilizes ERK3, leading to the formation of a complex with the cofactor MAP kinase-activated protein kinase 5 (MK5), thereby driving lipolysis. Mechanistically, we identified a downstream target of the ERK3/MK5 pathway, the transcription factor FOXO1, which promotes the expression of the major lipolytic enzyme ATGL. Finally, we provide evidence that targeted deletion of ERK3 in mouse adipocytes inhibits lipolysis, but elevates energy dissipation, promoting lean phenotype and ameliorating diabetes. Thus, ERK3/MK5 represents a previously unrecognized signaling axis in adipose tissue and an attractive target for future therapies aiming to combat obesity-induced diabetes.
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85
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Li W, Wu K, Liu Y, Yang Y, Wang W, Li X, Zhang Y, Zhang Q, Zhou R, Tang H. Molecular cloning of SLC35D3 and analysis of its role during porcine intramuscular preadipocyte differentiation. BMC Genet 2020; 21:20. [PMID: 32087688 PMCID: PMC7036214 DOI: 10.1186/s12863-020-0822-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/04/2020] [Indexed: 11/10/2022] Open
Abstract
Background Solute carrier family 35 (SLC35) is one of a large number of membrane transporter protein families. Member D3 of this family is thought to be involved in adipose deposition and metabolic control. Results We obtained 2238 bp cDNA of porcine SLC35D3, it contains a 1272 bp ORF, encoding a 423 amino acid polypeptide, and a 966 bp 3′ UTR. BLAST results revealed that the amino acid sequence of porcine SLC35D3 had the closest phylogenetic relationship with members of the genus Ovis aries. Further bioinformatics analysis showed that the SLC35D3 protein contains 8 transmembrane domains, and that there is no signal peptide structure. The secondary structure of the protein mainly contains 37.12% α-helixes, 7.8% in β-folds, and 33.57% random coils. mRNA expression analysis showed that SLC35D3 is expressed in lung, liver, heart, spleen, kidney, longissimus dorsi muscle (LDM), leaf fat (LF), and subcutaneous adipose tissue (SAT). To examine the effects of SLC35D3 expression on fat synthesis and catabolism, SLC35D3-siRNA was transfected into cultured intramuscular adipocytes. SLC35D3 silenced cells showed increased expression of genes related to fat synthesis, and increased deposition of intramuscular fat (IMF), abundance of lipid droplets, and the level of free fatty acid (FFA) in the culture medium. In contrast, the siRNA decreased the expression genes involved in fat catabolism. Conclusions Our results demonstrate that silenced SLC35D3 results in increased adipogenic processes in pig intramuscular adipocytes. These data represent the first exploration of SLC35D3 expression in swine, and provide valuable insights into the functions of SLC35D3 in adipocyte differentiation.
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Affiliation(s)
- Wentong Li
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China.,The State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Keliang Wu
- College of Animal Science and Technology, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Ying Liu
- The State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Yalan Yang
- School of Life Science and Engineering, Foshan University, Foshan, 528231, Guangdong, China
| | - Wenwen Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China
| | - Xiuxiu Li
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China
| | - Yanmin Zhang
- The State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Qin Zhang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China
| | - Rong Zhou
- The State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
| | - Hui Tang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China.
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86
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Jarc E, Petan T. A twist of FATe: Lipid droplets and inflammatory lipid mediators. Biochimie 2020; 169:69-87. [DOI: 10.1016/j.biochi.2019.11.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022]
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87
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Barayan D, Vinaik R, Auger C, Knuth CM, Abdullahi A, Jeschke MG. Inhibition of Lipolysis With Acipimox Attenuates Postburn White Adipose Tissue Browning and Hepatic Fat Infiltration. Shock 2020; 53:137-145. [PMID: 31425403 PMCID: PMC10880813 DOI: 10.1097/shk.0000000000001439] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Extensive burn injuries promote an increase in the lipolysis of white adipose tissue (WAT), a complication that enhances postburn hypermetabolism contributing to hyperlipidemia and hepatic steatosis. The systemic increase of free fatty acids (FFAs) due to burn-induced lipolysis and subsequent organ fatty infiltration may culminate in multiple organ dysfunction and, ultimately, death. Thus, reducing WAT lipolysis to diminish the mobilization of FFAs may render an effective means to improve outcomes postburn. Here, we investigated the metabolic effects of Acipimox, a clinically approved drug that suppresses lipolysis via inhibition of hormone-sensitive lipase (HSL). Using a murine model of thermal injury, we show that specific inhibition of HSL with Acipimox effectively suppresses burn-induced lipolysis in the inguinal WAT leading to lower levels of circulating FFAs at 7 days postburn (P < 0.05). The FFA substrate shortage indirectly repressed the thermogenic activation of adipose tissue after injury, reflected by the decrease in protein expression of key browning markers, UCP-1 (P < 0.001) and PGC-1α (P < 0.01). Importantly, reduction of FFA mobilization by Acipimox significantly decreased liver weight and intracellular fat accumulation (P < 0.05), suggesting that it may also improve organ function postburn. Our data validate the pharmacological inhibition of lipolysis as a potentially powerful therapeutic strategy to counteract the detrimental metabolic effects induced by burn.
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Affiliation(s)
- Dalia Barayan
- Institute of Medical Science, University of Toronto, Canada
| | - Roohi Vinaik
- Institute of Medical Science, University of Toronto, Canada
| | - Christopher Auger
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Canada
- Sunnybrook Research Institute, Toronto, Canada
| | - Carly M. Knuth
- Institute of Medical Science, University of Toronto, Canada
| | - Abdikarim Abdullahi
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Canada
- Sunnybrook Research Institute, Toronto, Canada
| | - Marc G. Jeschke
- Department of Surgery, Division of Plastic Surgery, University of Toronto, Canada
- Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Toronto, Canada
- Sunnybrook Research Institute, Toronto, Canada
- Institute of Medical Science, University of Toronto, Canada
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88
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Karczewska-Kupczewska M, Nikołajuk A, Majewski R, Filarski R, Stefanowicz M, Matulewicz N, Strączkowski M. Changes in adipose tissue lipolysis gene expression and insulin sensitivity after weight loss. Endocr Connect 2020; 9:90-100. [PMID: 31905163 PMCID: PMC6993275 DOI: 10.1530/ec-19-0507] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 12/22/2019] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Insulin resistance is a major pathophysiological link between obesity and its metabolic complications. Weight loss (WL) is an effective tool to prevent obesity-related diseases; however, the mechanisms of an improvement in insulin sensitivity (IS) after weight-reducing interventions are not completely understood. The aim of the present study was to analyze the relationships between IS and adipose tissue (AT) expression of the genes involved in the regulation of lipolysis in obese subjects after WL. METHODS Fifty-two obese subjects underwent weight-reducing dietary intervention program. The control group comprised 20 normal-weight subjects, examined at baseline only. Hyperinsulinemic-euglycemic clamp and s.c. AT biopsy with subsequent gene expression analysis were performed before and after the program. RESULTS AT expression of genes encoding lipases (PNPLA2, LIPE and MGLL) and lipid-droplet proteins enhancing (ABHD5) and inhibiting lipolysis (PLIN1 and CIDEA) were decreased in obese individuals in comparison with normal-weight individuals. The group of 38 obese participants completed dietary intervention program and clamp studies, which resulted in a significant WL and an improvement in mean IS. However, in nine subjects from this group IS did not improve in response to WL. AT expression of PNPLA2, LIPE and PLIN1 increased only in the group without IS improvement. CONCLUSIONS Excessive lipolysis may prevent an improvement in IS during WL. The change in AT PNPLA2 and LIPE expression was a negative predictor of the change in IS after WL.
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Affiliation(s)
- Monika Karczewska-Kupczewska
- Department of Internal Medicine and Metabolic Diseases, Medical University of Białystok, Białystok, Poland
- Correspondence should be addressed to M Karczewska-Kupczewska:
| | - Agnieszka Nikołajuk
- Department of Prophylaxis of Metabolic Diseases, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland
| | - Radosław Majewski
- Department of Prophylaxis of Metabolic Diseases, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland
| | - Remigiusz Filarski
- Department of Prophylaxis of Metabolic Diseases, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland
| | - Magdalena Stefanowicz
- Department of Metabolic Diseases, Medical University of Białystok, Białystok, Poland
| | - Natalia Matulewicz
- Department of Metabolic Diseases, Medical University of Białystok, Białystok, Poland
| | - Marek Strączkowski
- Department of Prophylaxis of Metabolic Diseases, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland
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89
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Yu L, Li Y, Grisé A, Wang H. CGI-58: Versatile Regulator of Intracellular Lipid Droplet Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:197-222. [PMID: 32705602 PMCID: PMC8063591 DOI: 10.1007/978-981-15-6082-8_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Comparative gene identification-58 (CGI-58), also known as α/β-hydrolase domain-containing 5 (ABHD5), is a member of a large family of proteins containing an α/β-hydrolase-fold. CGI-58 is well-known as the co-activator of adipose triglyceride lipase (ATGL), which is a key enzyme initiating cytosolic lipid droplet lipolysis. Mutations in either the human CGI-58 or ATGL gene cause an autosomal recessive neutral lipid storage disease, characterized by the excessive accumulation of triglyceride (TAG)-rich lipid droplets in the cytoplasm of almost all cell types. CGI-58, however, has ATGL-independent functions. Distinct phenotypes associated with CGI-58 deficiency commonly include ichthyosis (scaly dry skin), nonalcoholic steatohepatitis, and hepatic fibrosis. Through regulated interactions with multiple protein families, CGI-58 controls many metabolic and signaling pathways, such as lipid and glucose metabolism, energy balance, insulin signaling, inflammatory responses, and thermogenesis. Recent studies have shown that CGI-58 regulates the pathogenesis of common metabolic diseases in a tissue-specific manner. Future studies are needed to molecularly define ATGL-independent functions of CGI-58, including the newly identified serine protease activity of CGI-58. Elucidation of these versatile functions of CGI-58 may uncover fundamental cellular processes governing lipid and energy homeostasis, which may help develop novel approaches that counter against obesity and its associated metabolic sequelae.
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Affiliation(s)
- Liqing Yu
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Yi Li
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alison Grisé
- College of Computer, Math, and Natural Sciences, College of Behavioral and Social Sciences, University of Maryland, College Park, MD, USA
| | - Huan Wang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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90
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Trites MJ, Clugston RD. The role of adipose triglyceride lipase in lipid and glucose homeostasis: lessons from transgenic mice. Lipids Health Dis 2019; 18:204. [PMID: 31757217 PMCID: PMC6874817 DOI: 10.1186/s12944-019-1151-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/07/2019] [Indexed: 12/14/2022] Open
Abstract
The ability of mammals to store and draw on fat reserves has been a driving force throughout evolution in an environment with intermittent nutrient availability. The discovery of adipose triglyceride lipase (ATGL) as a triglyceride lipase provided a heightened understanding of the mechanisms governing mobilization of fat reserves from adipose tissue. ATGL catalyses the initial step in adipose triglyceride lipolysis, working in concert with other enzymes to mobilize triglyceride for energy production. In addition to the role of ATGL in adipose tissue triglyceride mobilization, ATGL plays crucial roles in regulating lipid homeostasis in other tissues. These roles have been characterized primarily using transgenic mice with tissue-specific ATGL ablation. For example, the global ATGL knockout induces a severe cardiac defect that results in premature mortality that is mimicked by inducible cardiomyocyte-specific ATGL knockout. Global- and adipose-specific ATGL ablation induces a whole-body shift from lipid metabolism to glucose metabolism to satisfy metabolic demand primarily facilitated by an increase in glucose uptake by skeletal muscle. Generation of liver-specific ATGL knockouts has implicated hepatic lipolysis as a critical component of normal liver function. Analysis of β-cell ATGL knockouts implicates the necessity of pancreatic ATGL in insulin secretion. The objective of this review is to discuss the contributions of ATGL to systemic lipid- and glucose-homeostasis discovered through the study of transgenic mice.
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Affiliation(s)
- Michael J Trites
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.,Group on the Molecular and Cell Biology of Lipids, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Robin D Clugston
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada. .,Group on the Molecular and Cell Biology of Lipids, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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91
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Rebollo-Hernanz M, Zhang Q, Aguilera Y, Martín-Cabrejas MA, Gonzalez de Mejia E. Phenolic compounds from coffee by-products modulate adipogenesis-related inflammation, mitochondrial dysfunction, and insulin resistance in adipocytes, via insulin/PI3K/AKT signaling pathways. Food Chem Toxicol 2019; 132:110672. [DOI: 10.1016/j.fct.2019.110672] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 06/24/2019] [Accepted: 07/10/2019] [Indexed: 02/07/2023]
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92
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Nag S, Patel S, Mani S, Hussain T. Role of angiotensin type 2 receptor in improving lipid metabolism and preventing adiposity. Mol Cell Biochem 2019; 461:195-204. [PMID: 31414336 DOI: 10.1007/s11010-019-03602-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/08/2019] [Indexed: 01/14/2023]
Abstract
Recent studies on mice with null mutation of the angiotensin type 2 receptor (AT2R) gene have implicated the involvement of AT2R in regulating adipocyte size and obesity, a major risk factor for metabolic syndrome. However, the outcome from these studies remains inconclusive. Therefore, current study was designed to test whether pharmacological activation of AT2R regulates adiposity and lipid metabolism. Male mice (5-weeks old) were pre-treated with vehicle or AT2R agonist (C21, 0.3 mg/kg, i.p., daily, for 4 days) and fed normal diet (ND). Then these animals were subdivided into ND and high-fat diet (HFD) regimen and concomitantly treated with vehicle or C21 through day 14. Vehicle-treated HFD-fed mice demonstrated an increase in epididymal white adipose tissue (eWAT) weight and adipocyte size, which were associated with increased eWAT expression of the lipogenic regulators, fatty acid binding protein and fatty acid synthase, decreased expression of adipose triglyceride lipase and increased expression of hormone-sensitive lipase. Interestingly, C21 pre-treatment altered HFD-induced changes in lipogenic and lipolytic regulators. C21 pre-treatment prevented decrease in expression of uncoupler protein-1 in brown adipose in HFD-fed mice, which was associated with increased core temperature. In addition, C21 pre-treatment ameliorated plasma-free fatty acids, triglycerides, insulin and tumor necrosis factor-α in HFD-fed mice. Ex-vivo study in isolated primary epididymal adipocytes revealed that C21 inhibits long chain fatty acid transporter, via a nitric oxide synthase/guanylate cyclase/protein kinase G-dependent pathway. Collectively, we propose pharmacological activation of AT2R regulates fatty acid metabolism and thermogenesis and prevents HFD-induced adiposity in mice.
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Affiliation(s)
- Sourashish Nag
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, 4849 Calhoun Rd., Health 2, Houston, TX, 77204, USA
| | - Sanket Patel
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, 4849 Calhoun Rd., Health 2, Houston, TX, 77204, USA
| | - Shailaja Mani
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Tahir Hussain
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, 4849 Calhoun Rd., Health 2, Houston, TX, 77204, USA.
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93
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Insulin Resistance-Related Proteins Are Overexpressed in Patients and Rats Treated With Olanzapine and Are Reverted by Pueraria in the Rat Model. J Clin Psychopharmacol 2019; 39:214-219. [PMID: 30946280 DOI: 10.1097/jcp.0000000000001028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Olanzapine, a commonly used second-generation antipsychotic, causes severe metabolic adverse effects, such as elevated blood glucose and insulin resistance (IR). Previous studies have proposed that overexpression of CD36, GGPPS, PTP-1B, GRK2, and adipose triglyceride lipase may contribute to the development of metabolic syndrome, and Pueraria could eliminate the metabolic adverse effects. The study aimed to investigate the association between olanzapine-associated IR and IR-related proteins (IRRPs) and determine the role of Pueraria in protection against the metabolic adverse effects of olanzapine. METHODS The expression levels of IRRPs were examined in schizophrenia patients and rat models with long-term olanzapine treatment. The efficacy of Pueraria on anti-IR by reducing the expression of IRRPs was comprehensively evaluated. RESULTS Our study demonstrated that in schizophrenia patients chronically treated with olanzapine, the expression levels of IRRPs in patients with a high IR index significantly increased, and these phenomena were further confirmed in a rat model. The expression levels of IRRPs were reduced significantly in Pueraria-treated IR rat models. The body weight, blood glucose, and IR index were restored to levels similar to those of normal controls. CONCLUSIONS The IRRPs are closely related to IR induced by olanzapine, and Pueraria could interfere with olanzapine-associated IR and revert overexpressed IRRPs. These findings suggest that IRRPs are key players in olanzapine-associated IR and that Pueraria has potential as a clinical drug to prevent the metabolic adverse effects of olanzapine, further improving compliance of schizophrenia patients.
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94
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Sun J, Huang X, Ji S, Ji H. Two faces of PPARα/NFκB signaling pathway in inflammatory responses to adipocytes lipolysis in grass carp Ctenopharyngodon idella. FISH & SHELLFISH IMMUNOLOGY 2019; 90:244-249. [PMID: 31029776 DOI: 10.1016/j.fsi.2019.04.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
Adipose tissue plays an important role in energy reservation, also be considered as vital immunological organ in animals. Adipocytes are the basic unit of adipose tissue, while little is known about the relationship between lipid metabolism and inflammatory response in fish adipocytes so far. In this study, forskolin was used to induce adipocyte lipolysis, and 5 μM forskolin and 30 μM forskolin both triggered lipolysis by increasing ATGL expression. Consequently, 30 μM Forskolin instead of 5 μM Forskolin induced the expression of NF-κB and its target pro-inflammatory cytokine genes including MCP-1, IL-6 and TNF-α. Further study found that low grade rate of lipolysis activated PPARα gene, and its inhibitory effect on the mRNA expression of NF-κB and its target genes inhibited the adipocyte inflammation. On the contrary, high grade rate of lipolysis increased the expression levels of NF-κB and its target genes, while their expression were attenuated by inhibition of reactive oxygen species (ROS) using α-tocopherol, suggesting that ROS generated due to the PPARα-mediated oxidation of released fatty acids from lipolysis may contribute to adipocyte inflammation. These results indicated that PPARα has dose effect in inflammatory responses to adipocyte lipolysis in grass carp. Taken together, grass carp adipocytes have immune activity. The inflammatory response is linked to the grade rate of adipocyte lipolysis in grass carp adipocytes, and excessive adipocyte lipolysis may promote a dynamic immune response in adipose tissue. This is the first study showing the regulatory effects of lipolysis on immune functions in fish adipocytes.
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Affiliation(s)
- Jian Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - XiaoCheng Huang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - ShangHong Ji
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Hong Ji
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
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95
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Ran L, Wang X, Mi A, Liu Y, Wu J, Wang H, Guo M, Sun J, Liu B, Li Y, Wang D, Jiang R, Wang N, Gao W, Zeng L, Huang L, Chen X, LeRoith D, Liang B, Li X, Wu Y. Loss of Adipose Growth Hormone Receptor in Mice Enhances Local Fatty Acid Trapping and Impairs Brown Adipose Tissue Thermogenesis. iScience 2019; 16:106-121. [PMID: 31154207 PMCID: PMC6545351 DOI: 10.1016/j.isci.2019.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/10/2019] [Accepted: 05/13/2019] [Indexed: 01/06/2023] Open
Abstract
Growth hormone (GH) binds to its receptor (growth hormone receptor [GHR]) to exert its pleiotropic effects on growth and metabolism. Disrupted GH/GHR actions not only fail growth but also are involved in many metabolic disorders, as shown in murine models with global or tissue-specific Ghr deficiency and clinical observations. Here we constructed an adipose-specific Ghr knockout mouse model Ad-GHRKO and studied the metabolic adaptability of the mice when stressed by high-fat diet (HFD) or cold. We found that disruption of adipose Ghr accelerated dietary obesity but protected the liver from ectopic adiposity through free fatty acid trapping. The heat-producing brown adipose tissue burning and white adipose tissue browning induced by cold were slowed in the absence of adipose Ghr but were recovered after prolonged cold acclimation. We conclude that at the expense of excessive subcutaneous fat accumulation and lower emergent cold tolerance, down-tuning adipose GHR signaling emulates a healthy obesity situation which has metabolic advantages against HFD.
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Affiliation(s)
- Liyuan Ran
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Xiaoshuang Wang
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Ai Mi
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Yanshuang Liu
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China
| | - Jin Wu
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Haoan Wang
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Meihua Guo
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Jie Sun
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China; College of Integrative Medicine, Dalian Medical University, Dalian 116044, China
| | - Bo Liu
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Youwei Li
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Dan Wang
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Rujiao Jiang
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Ning Wang
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Wenting Gao
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China
| | - Li Zeng
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China
| | - Lin Huang
- Department of Pathophysiology, Dalian Medical University, Dalian 116044, China
| | - Xiaoli Chen
- Department of Food Science and Nutrition, University of Minnesota, Twin Cities, MN, USA
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Icahn Mount Sinai School of Medicine, New York 10029, USA
| | - Bin Liang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China.
| | - Xin Li
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York 10010, USA; Department of Urology, New York University Langone Medical Center, New York 10016, USA; Perlmutter Cancer Institute, New York University Langone Medical Center, New York 10016, USA.
| | - Yingjie Wu
- Institute for Genome Engineered Animal Models of Human Diseases, Dalian Medical University, Dalian 116044, China; National Center of Genetically Engineered Animal Models for International Research, Dalian Medical University, Dalian 116044, China; Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian 116044, China; College of Integrative Medicine, Dalian Medical University, Dalian 116044, China; Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Icahn Mount Sinai School of Medicine, New York 10029, USA; Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York 10010, USA.
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96
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Adipose HuR protects against diet-induced obesity and insulin resistance. Nat Commun 2019; 10:2375. [PMID: 31147543 PMCID: PMC6542850 DOI: 10.1038/s41467-019-10348-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 05/06/2019] [Indexed: 02/07/2023] Open
Abstract
Human antigen R (HuR) is a member of the Hu family of RNA-binding proteins and is involved in many physiological processes. Obesity, as a worldwide healthcare problem, has attracted more and more attention. To investigate the role of adipose HuR, we generate adipose-specific HuR knockout (HuRAKO) mice. As compared with control mice, HuRAKO mice show obesity when induced with a high-fat diet, along with insulin resistance, glucose intolerance, hypercholesterolemia and increased inflammation in adipose tissue. The obesity of HuRAKO mice is attributed to adipocyte hypertrophy in white adipose tissue due to decreased expression of adipose triglyceride lipase (ATGL). HuR positively regulates ATGL expression by promoting the mRNA stability and translation of ATGL. Consistently, the expression of HuR in adipose tissue is reduced in obese humans. This study suggests that adipose HuR may be a critical regulator of ATGL expression and lipolysis and thereby controls obesity and metabolic syndrome. Human antigen R (HuR) is a RNA-binding protein. Here the authors investigate its role in adipose tissue and find that it protects mice from diet-induced obesity, prevents adipocyte hypertrophy, and promotes lipolysis, which may at least in part be due to HuR-dependent ATGL mRNA stability regulation demonstrated in-vitro.
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97
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Sim SY, Shin YE, Kim HK. Fucoidan from Undaria pinnatifida has anti-diabetic effects by stimulation of glucose uptake and reduction of basal lipolysis in 3T3-L1 adipocytes. Nutr Res 2019; 65:54-62. [PMID: 30952503 DOI: 10.1016/j.nutres.2019.02.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 01/22/2019] [Accepted: 02/15/2019] [Indexed: 01/14/2023]
Abstract
Fucoidan, a sulfated polysaccharide derived from brown seaweeds, has been shown to reduce blood glucose levels and improve insulin sensitivity in mice. We investigated the effects of fucoidan on lipid accumulation, lipolysis, and glucose uptake in 3T3-L1 cells to test the hypothesis that fucoidan exerts an anti-diabetic function by acting directly on adipocytes. The 3T3-L1 cells were treated with 10, 50, 100, and 200 μg/mL of fucoidan from Undaria pinnatifida. Oil Red O staining and AdipoRed assay were used to determine lipid accumulation during adipocyte differentiation. Fucoidan was shown to reduce lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity in a dose-dependent manner (P < .01). The expression of peroxisome proliferator-activated receptor γ (PPARγ), a major transcription factor associated with adipocyte differentiation, was also suppressed upon treatment with fucoidan. Treatment with fucoidan stimulated glucose uptake in normal adipocytes and restored insulin-stimulated glucose uptake in obesity-induced insulin resistant adipocytes, which were made by incubating hypertrophied 3T3-L1 cells with the conditioned media of RAW 264.7 macrophages (RAW-CM) (P < .01). In the presence of RAW-CM, fucoidan enhanced epinephrine-stimulated lipolysis but reduced basal lipolysis, as determined by non-esterified fatty acid into the culture medium (P < .001). These results suggest that fucoidan may have anti-diabetic effects by improving insulin-stimulated glucose uptake and inhibiting basal lipolysis in adipocytes without inducing adipogenesis.
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Affiliation(s)
- Sung-Yi Sim
- Department of Food Science and Nutrition, The Catholic University of Korea, Bucheon, Republic of Korea.
| | - Ye-Eun Shin
- Department of Food Science and Nutrition, The Catholic University of Korea, Bucheon, Republic of Korea.
| | - Hye-Kyeong Kim
- Department of Food Science and Nutrition, The Catholic University of Korea, Bucheon, Republic of Korea.
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98
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Chan CC, Damen MSMA, Alarcon PC, Sanchez-Gurmaches J, Divanovic S. Inflammation and Immunity: From an Adipocyte's Perspective. J Interferon Cytokine Res 2019; 39:459-471. [PMID: 30920343 DOI: 10.1089/jir.2019.0014] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Comprehension of adipocyte function has evolved beyond a long-held belief of their inert nature, as simple energy storing and releasing cells. Adipocytes, including white, brown, and beige, are capable mediators of global metabolic health, but their intersection with inflammation is a budding field of exploration. Evidence hints at a reciprocal relationship adipocytes share with immune cells. Adipocyte's capacity to behave in an "immune-like" manner and ability to sense inflammatory cues that subsequently alter core adipocyte function might play an important role in shaping immune responses. Clarifying this intricate relationship could uncover previously underappreciated contribution of adipocytes to inflammation-driven human health and disease. In this review, we highlight the potential of largely underappreciated adipocyte "immune-like" function and how it may contribute to inflammation, immunity, and pathology of various diseases.
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Affiliation(s)
- Calvin C Chan
- 1Medical Scientist Training Program, Immunology Graduate Program, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.,2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.,3Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Michelle S M A Damen
- 2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.,3Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Pablo C Alarcon
- 1Medical Scientist Training Program, Immunology Graduate Program, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.,2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.,3Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Joan Sanchez-Gurmaches
- 2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.,4Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,5Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Senad Divanovic
- 1Medical Scientist Training Program, Immunology Graduate Program, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.,2Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.,3Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,6Division of Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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99
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Cruz-Color LDL, Hernández-Nazará ZH, Maldonado-González M, Navarro-Muñíz E, Domínguez-Rosales JA, Torres-Baranda JR, Ruelas-Cinco EDC, Ramírez-Meza SM, Ruíz-Madrigal B. Association of the PNPLA2, SCD1 and Leptin Expression with Fat Distribution in Liver and Adipose Tissue From Obese Subjects. Exp Clin Endocrinol Diabetes 2019; 128:715-722. [PMID: 30754064 DOI: 10.1055/a-0829-6324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The expansion of adipose tissue is regulated by insulin and leptin through sterol regulatory element-binding protein-1c (SREBP-1c), up-regulating lipogenesis in tissues by Stearoylcoenzyme A desaturase 1 (SCD1) enzyme, while adipose triglyceride lipase (ATGL) enzyme is key in lipolysis. The research objective was to evaluate the expression of Sterol Regulatory Element Binding Transcription Factor 1 (SREBF1), SCD1, Patatin Like Phospholipase Domain Containing 2 (PNPLA2), and leptin (LEP) genes in hepatic-adipose tissue, and related them with the increment and distribution of fat depots of individuals without insulin resistance. Thirty-eight subjects undergoing elective cholecystectomy with liver and adipose tissue biopsies (subcutaneous-omental) are included. Tissue gene expression was assessed by qPCR and biochemical parameters determined. Individuals are classified according to the body mass index, classified as lean (control group, n=12), overweight (n=11) and obesity (n=15). Abdominal adiposity was determined by anthropometric and histopathological study of the liver. Increased SCD1 expression in omental adipose tissue (p=0.005) and PNPLA2 in liver (p=0.01) were found in the obesity group. PNPLA2 decreased expression in subcutaneous adipose tissue was significant in individuals with abdominal adiposity (p=0.017). Anthropometric parameters positively correlated with liver PNPLA2 and the expression of liver PNPLA2 with serum leptin. SCD1 increased levels may represent lipid storage activity in omental adipose tissue. Liver PNPLA2 increased expression could function as a primary compensatory event of visceral fat deposits associated to the leptin hormone related to the increase of adipose tissue.
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Affiliation(s)
- Lucía De la Cruz-Color
- Programa de Doctorado en Ciencias en Biología Molecular en Medicina, Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Zamira Helena Hernández-Nazará
- Instituto de Investigación de Enfermedades Crónico-Degenerativas del Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Montserrat Maldonado-González
- Laboratorio de Investigación del Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Eliseo Navarro-Muñíz
- División de Cirugía Nuevo Hospital Civil de Guadalajara "Dr. Juan I. Menchaca". Guadalajara, Jalisco, México
| | - José Alfredo Domínguez-Rosales
- Instituto de Investigación de Enfermedades Crónico-Degenerativas del Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - José Rodrigo Torres-Baranda
- Laboratorio de Investigación del Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Elizabeth Del Carmen Ruelas-Cinco
- Laboratorio de Investigación del Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Sandra Margarita Ramírez-Meza
- Laboratorio de Investigación del Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
| | - Bertha Ruíz-Madrigal
- Laboratorio de Investigación del Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara. Guadalajara, Jalisco, México
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100
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Chronic olanzapine administration causes metabolic syndrome through inflammatory cytokines in rodent models of insulin resistance. Sci Rep 2019; 9:1582. [PMID: 30733507 PMCID: PMC6367387 DOI: 10.1038/s41598-018-36930-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 11/23/2018] [Indexed: 01/16/2023] Open
Abstract
Olanzapine is a second-generation anti-psychotic drug used to prevent neuroinflammation in patients with schizophrenia. However, the long-term administration of olanzapine leads to insulin resistance (IR); the mechanisms of this effect remains poorly understood. Using cellular and rodent models of IR induced by olanzapine, we found that chronic olanzapine treatment induces differential inflammatory cytokine reactions in peripheral adipose and the central nervous system. Long-term treatment of olanzapine caused metabolic symptoms, including IR, by markedly elevating the plasma levels of pro-inflammatory cytokines, including IL-1ß, IL-6, IL-8 and TNFα; these findings are consistent with observations from schizophrenia patients chronically treated with olanzapine. Our observations of differential inflammatory cytokine responses in white adipose tissues from the prefrontal cortex in the brain indicated cell type-specific effects of the drug. These cytokines induced IR by activating NF-kB through the suppression of IkBα. Functional blockade of the components p50/p65 of NF-kB rescued olanzapine-induced IR in NIH-3T3 L1-derived adipocytes. Our findings demonstrate that olanzapine induces inflammatory cytokine reactions in peripheral tissues without adversely affecting the central nervous system and suggest that chronic olanzapine treatment of schizophrenia patients may cause inflammation-mediated IR with minimal or no adverse effects in the brain.
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