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Wang S, Xu B, Liang J, Feng Y, Han P, Shen J, Li X, Zheng M, Zhang T, Zhang C, Mi P, Zhang Y, Liu Z, Li S, Yuan D. Spatial Transcriptomic Study Reveals Heterogeneous Metabolic Adaptation and a Role of Pericentral PPARα/CAR/Ces2a Axis During Fasting in Mouse Liver. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2405240. [PMID: 39234807 DOI: 10.1002/advs.202405240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 08/13/2024] [Indexed: 09/06/2024]
Abstract
Spatial heterogeneity and plasticity of the mammalian liver are critical for systemic metabolic homeostasis in response to fluctuating nutritional conditions. Here, a spatially resolved transcriptomic landscape of mouse livers across fed, fasted and refed states using spatial transcriptomics is generated. This approach elucidated dynamic temporal-spatial gene cascades and how liver zonation-both expression levels and patterns-adapts to shifts in nutritional status. Importantly, the pericentral nuclear receptor Nr1i3 (CAR) as a pivotal regulator of triglyceride metabolism is pinpointed. It is showed that the activation of CAR in the pericentral region is transcriptionally governed by Pparα. During fasting, CAR activation enhances lipolysis by upregulating carboxylesterase 2a, playing a crucial role in maintaining triglyceride homeostasis. These findings lay the foundation for future mechanistic studies of liver metabolic heterogeneity and plasticity in response to nutritional status changes, offering insights into the zonated pathology that emerge during liver disease progression linked to nutritional imbalances.
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Affiliation(s)
- Shiguan Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
- Department of Clinical Laboratory, Qilu Hospital of Shandong University, Jinan, 250012, China
| | - Bowen Xu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
- Advanced Medical Research Institute, Shandong University, Jinan, 250012, China
| | - Jinyuan Liang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yawei Feng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Penghu Han
- Advanced Medical Research Institute, Shandong University, Jinan, 250012, China
| | - Jing Shen
- Advanced Medical Research Institute, Shandong University, Jinan, 250012, China
| | - Xinying Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Mengqi Zheng
- Advanced Medical Research Institute, Shandong University, Jinan, 250012, China
| | - Tingguo Zhang
- Institute of Pathology and Pathophysiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Cuijuan Zhang
- Institute of Pathology and Pathophysiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Ping Mi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yi Zhang
- Department of Clinical Laboratory, Qilu Hospital of Shandong University, Jinan, 250012, China
| | - Zhiping Liu
- Department of Biomedical Engineering, School of Control Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Shiyang Li
- Advanced Medical Research Institute, Shandong University, Jinan, 250012, China
| | - Detian Yuan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
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Steinhoff JS, Wagner C, Dähnhardt HE, Košić K, Meng Y, Taschler U, Pajed L, Yang N, Wulff S, Kiefer MF, Petricek KM, Flores RE, Li C, Dittrich S, Sommerfeld M, Guillou H, Henze A, Raila J, Wowro SJ, Schoiswohl G, Lass A, Schupp M. Adipocyte HSL is required for maintaining circulating vitamin A and RBP4 levels during fasting. EMBO Rep 2024; 25:2878-2895. [PMID: 38769419 PMCID: PMC11239848 DOI: 10.1038/s44319-024-00158-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/22/2024] Open
Abstract
Vitamin A (retinol) is distributed via the blood bound to its specific carrier protein, retinol-binding protein 4 (RBP4). Retinol-loaded RBP4 is secreted into the circulation exclusively from hepatocytes, thereby mobilizing hepatic retinoid stores that represent the major vitamin A reserves in the body. The relevance of extrahepatic retinoid stores for circulating retinol and RBP4 levels that are usually kept within narrow physiological limits is unknown. Here, we show that fasting affects retinoid mobilization in a tissue-specific manner, and that hormone-sensitive lipase (HSL) in adipose tissue is required to maintain serum concentrations of retinol and RBP4 during fasting in mice. We found that extracellular retinol-free apo-RBP4 induces retinol release by adipocytes in an HSL-dependent manner. Consistently, global or adipocyte-specific HSL deficiency leads to an accumulation of retinoids in adipose tissue and a drop of serum retinol and RBP4 during fasting, which affects retinoid-responsive gene expression in eye and kidney and lowers renal retinoid content. These findings establish a novel crosstalk between liver and adipose tissue retinoid stores for the maintenance of systemic vitamin A homeostasis during fasting.
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Affiliation(s)
- Julia S Steinhoff
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Carina Wagner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Henriette E Dähnhardt
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Kristina Košić
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Yueming Meng
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Ulrike Taschler
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Na Yang
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Sascha Wulff
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Marie F Kiefer
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Konstantin M Petricek
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Roberto E Flores
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Chen Li
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Sarah Dittrich
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Manuela Sommerfeld
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Hervé Guillou
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Andrea Henze
- Martin Luther University Halle-Wittenberg, Institute of Agricultural and Nutritional Sciences, Halle, Germany
- Junior Research Group ProAID, Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - Jens Raila
- Department of Physiology and Pathophysiology, Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - Sylvia J Wowro
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Gabriele Schoiswohl
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - Michael Schupp
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany.
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Li R, Liu Y, Wu J, Chen X, Lu Q, Xia K, Liu C, Sui X, Liu Y, Wang Y, Qiu Y, Chen J, Wang Y, Li R, Ba Y, Fang J, Huang W, Lu Z, Li Y, Liao X, Xiang AP, Huang Y. Adaptive Metabolic Responses Facilitate Blood-Brain Barrier Repair in Ischemic Stroke via BHB-Mediated Epigenetic Modification of ZO-1 Expression. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400426. [PMID: 38666466 PMCID: PMC11220715 DOI: 10.1002/advs.202400426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/11/2024] [Indexed: 07/04/2024]
Abstract
Adaptive metabolic responses and innate metabolites hold promising therapeutic potential for stroke, while targeted interventions require a thorough understanding of underlying mechanisms. Adiposity is a noted modifiable metabolic risk factor for stroke, and recent research suggests that it benefits neurological rehabilitation. During the early phase of experimental stroke, the lipidomic results showed that fat depots underwent pronounced lipolysis and released fatty acids (FAs) that feed into consequent hepatic FA oxidation and ketogenesis. Systemic supplementation with the predominant ketone beta-hydroxybutyrate (BHB) is found to exert discernible effects on preserving blood-brain barrier (BBB) integrity and facilitating neuroinflammation resolution. Meanwhile, blocking FAO-ketogenesis processes by administration of CPT1α antagonist or shRNA targeting HMGCS2 exacerbated endothelial damage and aggravated stroke severity, whereas BHB supplementation blunted these injuries. Mechanistically, it is unveiled that BHB infusion is taken up by monocarboxylic acid transporter 1 (MCT1) specifically expressed in cerebral endothelium and upregulated the expression of tight junction protein ZO-1 by enhancing local β-hydroxybutyrylation of H3K9 at the promoter of TJP1 gene. Conclusively, an adaptive metabolic mechanism is elucidated by which acute lipolysis stimulates FAO-ketogenesis processes to restore BBB integrity after stroke. Ketogenesis functions as an early metabolic responder to restrain stroke progression, providing novel prospectives for clinical translation.
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Wang H, Guo S, Gao H, Ding J, Li H, Kong X, Zhang S, He M, Feng Y, Wu W, Xu K, Chen Y, Zhang H, Liu T, Kong X. Myostatin regulates energy homeostasis through autocrine- and paracrine-mediated microenvironment communication. J Clin Invest 2024; 134:e178303. [PMID: 38889010 PMCID: PMC11324308 DOI: 10.1172/jci178303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/17/2024] [Indexed: 06/20/2024] Open
Abstract
Myostatin (MSTN) has long been recognized as a critical regulator of muscle mass. Recently, there has been increasing interest in its role in metabolism. In our study, we specifically knocked out MSTN in brown adipose tissue (BAT) from mice (MSTNΔUCP1) and found that the mice gained more weight than did controls when fed a high-fat diet, with progressive hepatosteatosis and impaired skeletal muscle activity. RNA-Seq analysis indicated signatures of mitochondrial dysfunction and inflammation in the MSTN-ablated BAT. Further studies demonstrated that Kruppel-like factor 4 (KLF4) was responsible for the metabolic phenotypes observed, whereas fibroblast growth factor 21 (FGF21) contributed to the microenvironment communication between adipocytes and macrophages induced by the loss of MSTN. Moreover, the MSTN/SMAD2/3-p38 signaling pathway mediated the expression of KLF4 and FGF21 in adipocytes. In summary, our findings suggest that brown adipocyte-derived MSTN regulated BAT thermogenesis via autocrine and paracrine effects on adipocytes or macrophages, ultimately regulating systemic energy homeostasis.
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Affiliation(s)
- Hui Wang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Shanshan Guo
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Huanqing Gao
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Jiyang Ding
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Hongyun Li
- Department of Sports Medicine and Arthroscopy Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Xingyu Kong
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Shuang Zhang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Muyang He
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
- Shanghai Medical College, Fudan University, Shanghai, China
| | - Yonghao Feng
- Department of Endocrinology, Jinshan Hospital, Fudan University, Shanghai, China
| | - Wei Wu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
| | - Kexin Xu
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Yuxuan Chen
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
| | - Hanyin Zhang
- Shanghai Medical College, Fudan University, Shanghai, China
| | - Tiemin Liu
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
- School of Life Sciences, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Xingxing Kong
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Human Phenome Institute, Fudan University, Shanghai, China
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, Shanghai, China
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5
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Ruppert PMM, Kersten S. Mechanisms of hepatic fatty acid oxidation and ketogenesis during fasting. Trends Endocrinol Metab 2024; 35:107-124. [PMID: 37940485 DOI: 10.1016/j.tem.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 11/10/2023]
Abstract
Fasting is part of many weight management and health-boosting regimens. Fasting causes substantial metabolic adaptations in the liver that include the stimulation of fatty acid oxidation and ketogenesis. The induction of fatty acid oxidation and ketogenesis during fasting is mainly driven by interrelated changes in plasma levels of various hormones and an increase in plasma nonesterified fatty acid (NEFA) levels and is mediated transcriptionally by the peroxisome proliferator-activated receptor (PPAR)α, supported by CREB3L3 (cyclic AMP-responsive element-binding protein 3 like 3). Compared with men, women exhibit higher ketone levels during fasting, likely due to higher NEFA availability, suggesting that the metabolic response to fasting shows sexual dimorphism. Here, we synthesize the current molecular knowledge on the impact of fasting on hepatic fatty acid oxidation and ketogenesis.
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Affiliation(s)
- Philip M M Ruppert
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 C Odense, Denmark
| | - Sander Kersten
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition and Health, Wageningen University, 6708 WE Wageningen, The Netherlands; Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
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Falkevall A, Mehlem A, Folestad E, Ning FC, Osorio-Conles Ó, Radmann R, de Hollanda A, Wright SD, Scotney P, Nash A, Eriksson U. Inhibition of VEGF-B signaling prevents non-alcoholic fatty liver disease development by targeting lipolysis in the white adipose tissue. J Hepatol 2023; 78:901-913. [PMID: 36717026 DOI: 10.1016/j.jhep.2023.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/22/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
BACKGROUND & AIMS Hepatic steatosis is a hallmark of non-alcoholic fatty liver disease (NAFLD), a common comorbidity in type 2 diabetes mellitus (T2DM). The pathogenesis of NAFLD is complex and involves the crosstalk between the liver and the white adipose tissue (WAT). Vascular endothelial growth factor B (VEGF-B) has been shown to control tissue lipid accumulation by regulating the transport properties of the vasculature. The role of VEGF-B signaling and the contribution to hepatic steatosis and NAFLD in T2DM is currently not understood. METHODS C57BL/6 J mice treated with a neutralizing antibody against VEGF-B, or mice with adipocyte-specific overexpression or under-expression of VEGF-B (AdipoqCre+/VEGF-BTG/+ mice and AdipoqCre+/Vegfbfl/+mice) were subjected to a 6-month high-fat diet (HFD), or chow-diet, whereafter NAFLD development was assessed. VEGF-B expression was analysed in WAT biopsies from patients with obesity and NAFLD in a pre-existing clinical cohort (n = 24 patients with NAFLD and n = 24 without NAFLD) and correlated to clinicopathological features. RESULTS Pharmacological inhibition of VEGF-B signaling in diabetic mice reduced hepatic steatosis and NAFLD by blocking WAT lipolysis. Mechanistically we show, by using HFD-fed AdipoqCre+/VEGF-BTG/+ mice and HFD-fed AdipoqCre+/Vegfbfl/+mice, that inhibition of VEGF-B signaling targets lipolysis in adipocytes. Reducing VEGF-B signaling ameliorated NAFLD by decreasing WAT inflammation, resolving WAT insulin resistance, and lowering the activity of the hormone sensitive lipase. Analyses of human WAT biopsies from individuals with NAFLD provided evidence supporting the contribution of VEGF-B signaling to NAFLD development. VEGF-B expression levels in adipocytes from two WAT depots correlated with development of dysfunctional WAT and NAFLD in humans. CONCLUSIONS Taken together, our data from mouse models and humans suggest that VEGF-B antagonism may represent an approach to combat NAFLD by targeting hepatic steatosis through suppression of lipolysis. IMPACT AND IMPLICATIONS Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity in type 2 diabetes mellitus (T2DM) and has a global prevalence of between 25-29%. There are currently no approved drugs for NAFLD, and given the scale of the ongoing diabetes epidemics, there is an urgent need to identify new treatment options. Our work suggests that VEGF-B antagonism may represent an approach to combat NAFLD by targeting hepatic steatosis through suppression of lipolysis. The neutralizing anti-VEGF-B antibody, which was used in this study, has already entered clinical trials for patients with diabetes. Therefore, we believe that our results are of great general interest to a broad audience, including patients and patient organizations, the medical community, academia, the life science industry and the public.
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Affiliation(s)
- Annelie Falkevall
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Annika Mehlem
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Erika Folestad
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Frank Chenfei Ning
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Óscar Osorio-Conles
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Rosa Radmann
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ana de Hollanda
- Obesity Unit. Clinical Hospital of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatologia de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain
| | | | | | - Andrew Nash
- CSL Innovation Pty Ltd, Parkville, Victoria, Australia
| | - Ulf Eriksson
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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Zhao X, Amevor FK, Cui Z, Wan Y, Xue X, Peng C, Li Y. Steatosis in metabolic diseases: A focus on lipolysis and lipophagy. Biomed Pharmacother 2023; 160:114311. [PMID: 36764133 DOI: 10.1016/j.biopha.2023.114311] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/11/2023] Open
Abstract
Fatty acids (FAs), as part of lipids, are involved in cell membrane composition, cellular energy storage, and cell signaling. FAs can also be toxic when their concentrations inside and/or outside the cell exceed physiological levels, which is called "lipotoxicity", and steatosis is a form of lipotoxity. To facilitate the storage of large quantities of FAs in cells, they undergo a process called lipolysis or lipophagy. This review focuses on the effects of lipolytic enzymes including cytoplasmic "neutral" lipolysis, lysosomal "acid" lipolysis, and lipophagy. Moreover, the impact of related lipolytic enzymes on lipid metabolism homeostasis and energy conservation, as well as their role in lipid-related metabolic diseases. In addition, we describe how they affect lipid metabolism homeostasis and energy conservation in lipid-related metabolic diseases with a focus on hepatic steatosis and cancer and the pathogenesis and therapeutic targets of AMPK/SIRTs/FOXOs, PI3K/Akt, PPARs/PGC-1α, MAPK/ERK1/2, TLR4/NF-κB, AMPK/mTOR/TFEB, Wnt/β-catenin through immune inflammation, oxidative stress and autophagy-related pathways. As well as the current application of lipolytic enzyme inhibitors (especially Monoacylglycerol lipase (MGL) inhibitors) to provide new strategies for future exploration of metabolic programming in metabolic diseases.
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Affiliation(s)
- Xingtao Zhao
- State Key Laboratory of Southwestern Chinese Medicine Resources, Ministry of Education, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Felix Kwame Amevor
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
| | - Zhifu Cui
- College of Animal Science and Technology, Southwest University, Chongqing 400715, China.
| | - Yan Wan
- State Key Laboratory of Southwestern Chinese Medicine Resources, Ministry of Education, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Xinyan Xue
- State Key Laboratory of Southwestern Chinese Medicine Resources, Ministry of Education, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, Ministry of Education, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Yunxia Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Ministry of Education, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
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8
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Wu D, Zhang Z, Sun W, Yan Y, Jing M, Ma S. The effect of G0S2 on insulin sensitivity: A proteomic analysis in a G0S2-overexpressed high-fat diet mouse model. Front Endocrinol (Lausanne) 2023; 14:1130350. [PMID: 37033250 PMCID: PMC10076770 DOI: 10.3389/fendo.2023.1130350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
BACKGROUND Previous research has shown a tight relationship between the G0/G1 switch gene 2 (G0S2) and metabolic diseases such as non-alcoholic fatty liver disease (NAFLD) and obesity and diabetes, and insulin resistance has been shown as the major risk factor for both NAFLD and T2DM. However, the mechanisms underlying the relationship between G0S2 and insulin resistance remain incompletely understood. Our study aimed to confirm the effect of G0S2 on insulin resistance, and determine whether the insulin resistance in mice fed a high-fat diet (HFD) results from G0S2 elevation. METHODS In this study, we extracted livers from mice that consumed HFD and received tail vein injections of AD-G0S2/Ad-LacZ, and performed a proteomics analysis. RESULTS Proteomic analysis revealed that there was a total of 125 differentially expressed proteins (DEPs) (56 increased and 69 decreased proteins) among the identified 3583 proteins. Functional enrichment analysis revealed that four insulin signaling pathway-associated proteins were significantly upregulated and five insulin signaling pathway -associated proteins were significantly downregulated. CONCLUSION These findings show that the DEPs, which were associated with insulin resistance, are generally consistent with enhanced insulin resistance in G0S2 overexpression mice. Collectively, this study demonstrates that G0S2 may be a potential target gene for the treatment of obesity, NAFLD, and diabetes.
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Affiliation(s)
- Dongming Wu
- College of First Clinical Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhenyuan Zhang
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Wenxiu Sun
- Department of Nursing, Taishan Vocational College of Nursing, Taian, China
| | - Yong Yan
- Department of Transfusion Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Mengzhe Jing
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
| | - Shizhan Ma
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Jinan, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China
- Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Jinan, China
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9
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Schratter M, Lass A, Radner FPW. ABHD5-A Regulator of Lipid Metabolism Essential for Diverse Cellular Functions. Metabolites 2022; 12:1015. [PMID: 36355098 PMCID: PMC9694394 DOI: 10.3390/metabo12111015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/19/2022] [Accepted: 10/23/2022] [Indexed: 11/12/2023] Open
Abstract
The α/β-Hydrolase domain-containing protein 5 (ABHD5; also known as comparative gene identification-58, or CGI-58) is the causative gene of the Chanarin-Dorfman syndrome (CDS), a disorder mainly characterized by systemic triacylglycerol accumulation and a severe defect in skin barrier function. The clinical phenotype of CDS patients and the characterization of global and tissue-specific ABHD5-deficient mouse strains have demonstrated that ABHD5 is a crucial regulator of lipid and energy homeostasis in various tissues. Although ABHD5 lacks intrinsic hydrolase activity, it functions as a co-activating enzyme of the patatin-like phospholipase domain-containing (PNPLA) protein family that is involved in triacylglycerol and glycerophospholipid, as well as sphingolipid and retinyl ester metabolism. Moreover, ABHD5 interacts with perilipins (PLINs) and fatty acid-binding proteins (FABPs), which are important regulators of lipid homeostasis in adipose and non-adipose tissues. This review focuses on the multifaceted role of ABHD5 in modulating the function of key enzymes in lipid metabolism.
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Affiliation(s)
- Margarita Schratter
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, 8010 Graz, Austria
| | - Franz P. W. Radner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
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10
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Mooli RGR, Ramakrishnan SK. Emerging Role of Hepatic Ketogenesis in Fatty Liver Disease. Front Physiol 2022; 13:946474. [PMID: 35860662 PMCID: PMC9289363 DOI: 10.3389/fphys.2022.946474] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/08/2022] [Indexed: 11/18/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver diseases, arise from non-alcoholic fatty liver (NAFL) characterized by excessive fat accumulation as triglycerides. Although NAFL is benign, it could progress to non-alcoholic steatohepatitis (NASH) manifested with inflammation, hepatocyte damage and fibrosis. A subset of NASH patients develops end-stage liver diseases such as cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD is highly complex and strongly associated with perturbations in lipid and glucose metabolism. Lipid disposal pathways, in particular, impairment in condensation of acetyl-CoA derived from β-oxidation into ketogenic pathway strongly influence the hepatic lipid loads and glucose metabolism. Current evidence suggests that ketogenesis dispose up to two-thirds of the lipids entering the liver, and its dysregulation significantly contribute to the NAFLD pathogenesis. Moreover, ketone body administration in mice and humans shows a significant improvement in NAFLD. This review focuses on hepatic ketogenesis and its role in NAFLD pathogenesis. We review the possible mechanisms through which impaired hepatic ketogenesis may promote NAFLD progression. Finally, the review sheds light on the therapeutic implications of a ketogenic diet in NAFLD.
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11
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Fougerat A, Schoiswohl G, Polizzi A, Régnier M, Wagner C, Smati S, Fougeray T, Lippi Y, Lasserre F, Raho I, Melin V, Tramunt B, Métivier R, Sommer C, Benhamed F, Alkhoury C, Greulich F, Jouffe C, Emile A, Schupp M, Gourdy P, Dubot P, Levade T, Meynard D, Ellero-Simatos S, Gamet-Payrastre L, Panasyuk G, Uhlenhaut H, Amri EZ, Cruciani-Guglielmacci C, Postic C, Wahli W, Loiseau N, Montagner A, Langin D, Lass A, Guillou H. ATGL-dependent white adipose tissue lipolysis controls hepatocyte PPARα activity. Cell Rep 2022; 39:110910. [PMID: 35675775 DOI: 10.1016/j.celrep.2022.110910] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/22/2022] [Accepted: 05/12/2022] [Indexed: 11/24/2022] Open
Abstract
In hepatocytes, peroxisome proliferator-activated receptor α (PPARα) orchestrates a genomic and metabolic response required for homeostasis during fasting. This includes the biosynthesis of ketone bodies and of fibroblast growth factor 21 (FGF21). Here we show that in the absence of adipose triglyceride lipase (ATGL) in adipocytes, ketone body and FGF21 production is impaired upon fasting. Liver gene expression analysis highlights a set of fasting-induced genes sensitive to both ATGL deletion in adipocytes and PPARα deletion in hepatocytes. Adipose tissue lipolysis induced by activation of the β3-adrenergic receptor also triggers such PPARα-dependent responses not only in the liver but also in brown adipose tissue (BAT). Intact PPARα activity in hepatocytes is required for the cross-talk between adipose tissues and the liver during fat mobilization.
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Affiliation(s)
- Anne Fougerat
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Gabriele Schoiswohl
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, 8010 Graz, Austria; BioTechMed-Graz, Graz, Austria; Department of Pharmacology and Toxicology, University of Graz, Humboldtstraße 46/II, 8010 Graz, Austria
| | - Arnaud Polizzi
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Marion Régnier
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Carina Wagner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, 8010 Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Sarra Smati
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France; Nantes Université, CHU Nantes, CNRS, INSERM, l'Institut du Thorax, 44000 Nantes, France
| | - Tiffany Fougeray
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Yannick Lippi
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Frederic Lasserre
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Ilyès Raho
- Université Paris Cité, BFA, UMR 8251, CNRS, 75013 Paris, France
| | - Valentine Melin
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Blandine Tramunt
- Institute of Metabolic and Cardiovascular Diseases, I2MC, University of Toulouse, INSERM, Toulouse III University - Paul Sabatier (UPS), Toulouse, France; Service de Diabétologie, Maladies Métaboliques et Nutrition, CHU de Toulouse, Toulouse, France
| | - Raphaël Métivier
- Institut de Génétique et Développement de Rennes, Université de Rennes, UMR 6290 CNRS, Rennes, France
| | - Caroline Sommer
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Fadila Benhamed
- Institut Cochin, Université Paris Cité, CNRS, INSERM, F-75014 Paris, France
| | - Chantal Alkhoury
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker-Enfants Malades, F-75015 Paris, France
| | - Franziska Greulich
- Metabolic Programming, TUM School of Life Sciences, ZIEL Institute for Food & Health, Gregor-Mendel-Strasse 2, 85354 Freising, Germany
| | - Céline Jouffe
- Helmholtz Diabetes Center (IDO, IDC, IDE), Helmholtz Center Munich HMGU, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Anthony Emile
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Michael Schupp
- Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10115 Berlin, Germany
| | - Pierre Gourdy
- Institute of Metabolic and Cardiovascular Diseases, I2MC, University of Toulouse, INSERM, Toulouse III University - Paul Sabatier (UPS), Toulouse, France; Service de Diabétologie, Maladies Métaboliques et Nutrition, CHU de Toulouse, Toulouse, France
| | - Patricia Dubot
- INSERM U1037, CRCT, Université Paul Sabatier, 31059 Toulouse, France; Laboratoire de Biochimie, CHU Toulouse, Toulouse, France
| | - Thierry Levade
- INSERM U1037, CRCT, Université Paul Sabatier, 31059 Toulouse, France; Laboratoire de Biochimie, CHU Toulouse, Toulouse, France
| | - Delphine Meynard
- Institute of Digestive Health Research, IRSD, INSERM U1220, Toulouse, France
| | - Sandrine Ellero-Simatos
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Laurence Gamet-Payrastre
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Ganna Panasyuk
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker-Enfants Malades, F-75015 Paris, France
| | - Henriette Uhlenhaut
- Metabolic Programming, TUM School of Life Sciences, ZIEL Institute for Food & Health, Gregor-Mendel-Strasse 2, 85354 Freising, Germany; Helmholtz Diabetes Center (IDO, IDC, IDE), Helmholtz Center Munich HMGU, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | | | | | - Catherine Postic
- Institut Cochin, Université Paris Cité, CNRS, INSERM, F-75014 Paris, France
| | - Walter Wahli
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France; Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore 308232, Singapore; Center for Integrative Genomics, University of Lausanne, Le Génopode, 1015 Lausanne, Switzerland
| | - Nicolas Loiseau
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Alexandra Montagner
- Institute of Metabolic and Cardiovascular Diseases, I2MC, University of Toulouse, INSERM, Toulouse III University - Paul Sabatier (UPS), Toulouse, France
| | - Dominique Langin
- Institute of Metabolic and Cardiovascular Diseases, I2MC, University of Toulouse, INSERM, Toulouse III University - Paul Sabatier (UPS), Toulouse, France; Laboratoire de Biochimie, CHU Toulouse, Toulouse, France; Academic Institute of France (IUF), Paris, France
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, 8010 Graz, Austria; BioTechMed-Graz, Graz, Austria.
| | - Hervé Guillou
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France.
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12
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Wagner C, Hois V, Eggeling A, Pusch LM, Pajed L, Starlinger P, Claudel T, Trauner M, Zimmermann R, Taschler U, Lass A. KIAA1363 affects retinyl ester turnover in cultured murine and human hepatic stellate cells. J Lipid Res 2022; 63:100173. [PMID: 35101424 PMCID: PMC8953624 DOI: 10.1016/j.jlr.2022.100173] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/14/2021] [Accepted: 01/19/2022] [Indexed: 12/18/2022] Open
Abstract
Large quantities of vitamin A are stored as retinyl esters (REs) in specialized liver cells, the hepatic stellate cells (HSCs). To date, the enzymes controlling RE degradation in HSCs are poorly understood. In this study, we identified KIAA1363 (also annotated as arylacetamide deacetylase 1 or neutral cholesterol ester hydrolase 1) as a novel RE hydrolase. We show that KIAA1363 is expressed in the liver, mainly in HSCs, and exhibits RE hydrolase activity at neutral pH. Accordingly, addition of the KIAA1363-specific inhibitor JW480 largely reduced RE hydrolase activity in lysates of cultured murine and human HSCs. Furthermore, cell fractionation experiments and confocal microscopy studies showed that KIAA1363 localizes to the endoplasmic reticulum. We demonstrate that overexpression of KIAA1363 in cells led to lower cellular RE content after a retinol loading period. Conversely, pharmacological inhibition or shRNA-mediated silencing of KIAA1363 expression in cultured murine and human HSCs attenuated RE degradation. Together, our data suggest that KIAA1363 affects vitamin A metabolism of HSCs by hydrolyzing REs at the endoplasmic reticulum, thereby counteracting retinol esterification and RE storage in lipid droplets.
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Affiliation(s)
- Carina Wagner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Victoria Hois
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Annalena Eggeling
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Lisa-Maria Pusch
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Patrick Starlinger
- Department of Surgery, General Hospital, Medical University of Vienna, Vienna, Austria; Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | - Thierry Claudel
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria; Field of Excellence BioHealth, University of Graz, Graz, Austria.
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13
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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: 226] [Impact Index Per Article: 75.3] [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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14
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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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15
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Cui A, Ding D, Li Y. Regulation of Hepatic Metabolism and Cell Growth by the ATF/CREB Family of Transcription Factors. Diabetes 2021; 70:653-664. [PMID: 33608424 PMCID: PMC7897342 DOI: 10.2337/dbi20-0006] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
The liver is a major metabolic organ that regulates the whole-body metabolic homeostasis and controls hepatocyte proliferation and growth. The ATF/CREB family of transcription factors integrates nutritional and growth signals to the regulation of metabolism and cell growth in the liver, and deregulated ATF/CREB family signaling is implicated in the progression of type 2 diabetes, nonalcoholic fatty liver disease, and cancer. This article focuses on the roles of the ATF/CREB family in the regulation of glucose and lipid metabolism and cell growth and its importance in liver physiology. We also highlight how the disrupted ATF/CREB network contributes to human diseases and discuss the perspectives of therapeutically targeting ATF/CREB members in the clinic.
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Affiliation(s)
- Aoyuan Cui
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Dong Ding
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yu Li
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
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16
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Zhao N, Tan H, Wang L, Han L, Cheng Y, Feng Y, Li T, Liu X. Palmitate induces fat accumulation via repressing FoxO1-mediated ATGL-dependent lipolysis in HepG2 hepatocytes. PLoS One 2021; 16:e0243938. [PMID: 33449950 PMCID: PMC7810308 DOI: 10.1371/journal.pone.0243938] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/30/2020] [Indexed: 02/05/2023] Open
Abstract
Obesity is closely associated with non-alcoholic fatty liver disease (NAFLD), and elevated serum palmitate is the link between obesity and excessive hepatic lipid accumulation. Forkhead box O-1 (FoxO1) is one of the FoxO family members of transcription factors and can stimulate adipose triglyceride lipase (ATGL) and suppress its inhibitor G0/G1 switch gene 2 (G0S2) expression in the liver. However, previous researches have also shown conflicting results regarding the role of FoxO1 in hepatic lipid accumulation. We therefore examined the role of FoxO1 as a downstream suppressor to palmitate-stimulated hepatic steatosis. Palmitate significantly promoted lipid accumulation but inhibited lipid decomposition in human HepG2 hepatoma cells. Palmitate also significantly reduced FoxO1, ATGL and its activator comparative gene identification-58 (CGI-58) expression but increased peroxisome proliferator-activated receptorγ (PPARγ) and its target gene G0S2 expression. FoxO1 overexpression significantly increased palmitate-inhibited ATGL and CGI-58 expression but reduced palmitate-stimulated PPARγ and its target gene G0S2 expression. FoxO1 overexpression also inhibited lipid accumulation and promoted lipolysis in palmitate-treated hepatocytes. Overall, these results indicate that FoxO1-mediated ATGL-dependent lipolysis may be an effective molecular mechanism in protecting hepatocytes from palmitate-induced fat accumulation.
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Affiliation(s)
- Naiqian Zhao
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
- * E-mail:
| | - Huiwen Tan
- Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Li Wang
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Le Han
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yanli Cheng
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Ying Feng
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Ting Li
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Xiaoling Liu
- Department of Gerontology, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
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17
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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: 114] [Impact Index Per Article: 28.5] [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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Wade H, Pan K, Su Q. CREBH: A Complex Array of Regulatory Mechanisms in Nutritional Signaling, Metabolic Inflammation, and Metabolic Disease. Mol Nutr Food Res 2020; 65:e2000771. [DOI: 10.1002/mnfr.202000771] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Henry Wade
- Institute for Global Food Security School of Biological Sciences Queen's University Belfast Belfast BT9 5DL UK
| | - Kaichao Pan
- Institute for Global Food Security School of Biological Sciences Queen's University Belfast Belfast BT9 5DL UK
| | - Qiaozhu Su
- Institute for Global Food Security School of Biological Sciences Queen's University Belfast Belfast BT9 5DL UK
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19
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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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20
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de la Rosa Rodriguez MA, Kersten S. Regulation of lipid droplet homeostasis by hypoxia inducible lipid droplet associated HILPDA. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158738. [PMID: 32417386 DOI: 10.1016/j.bbalip.2020.158738] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/17/2020] [Accepted: 05/06/2020] [Indexed: 12/28/2022]
Abstract
Nearly all cell types have the ability to store excess energy as triglycerides in specialized organelles called lipid droplets. The formation and degradation of lipid droplets is governed by a diverse set of enzymes and lipid droplet-associated proteins. One of the lipid droplet-associated proteins is Hypoxia Inducible Lipid Droplet Associated (HILPDA). HILPDA was originally discovered in a screen to identify novel hypoxia-inducible proteins. Apart from hypoxia, levels of HILPDA are induced by fatty acids and adrenergic agonists. HILPDA is a small protein of 63 amino acids in humans and 64 amino acids in mice. Inside cells, HILPDA is located in the endoplasmic reticulum and around lipid droplets. Gain- and loss-of-function experiments have demonstrated that HILPDA promotes lipid storage in hepatocytes, macrophages and cancer cells. HILPDA increases lipid droplet accumulation at least partly by inhibiting triglyceride hydrolysis via ATGL and stimulating triglyceride synthesis via DGAT1. Overall, HILPDA is a novel regulatory signal that adjusts triglyceride storage and the intracellular availability of fatty acids to the external fatty acid supply and the capacity for oxidation.
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Affiliation(s)
- Montserrat A de la Rosa Rodriguez
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands.
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21
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Wagner C, Hois V, Pajed L, Pusch LM, Wolinski H, Trauner M, Zimmermann R, Taschler U, Lass A. Lysosomal acid lipase is the major acid retinyl ester hydrolase in cultured human hepatic stellate cells but not essential for retinyl ester degradation. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158730. [PMID: 32361002 PMCID: PMC7279957 DOI: 10.1016/j.bbalip.2020.158730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 04/22/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023]
Abstract
Vitamin A is stored as retinyl esters (REs) in lipid droplets of hepatic stellate cells (HSCs). To date, two different pathways are known to facilitate the breakdown of REs: (i) Hydrolysis of REs by neutral lipases, and (ii) whole lipid droplet degradation in autolysosomes by acid hydrolysis. In this study, we evaluated the contribution of neutral and acid RE hydrolases to the breakdown of REs in human HSCs. (R)-Bromoenol lactone (R-BEL), inhibitor of adipose triglyceride lipase (ATGL) and patatin-like phospholipase domain-containing 3 (PNPLA3), the hormone-sensitive lipase (HSL) inhibitor 76-0079, as well as the serine-hydrolase inhibitor Orlistat reduced neutral RE hydrolase activity of LX-2 cell-lysates between 20 and 50%. Interestingly, in pulse-chase experiments, R-BEL, 76-0079, as well as Orlistat exerted little to no effect on cellular RE breakdown of LX-2 cells as well as primary human HSCs. In contrast, Lalistat2, a specific lysosomal acid lipase (LAL) inhibitor, virtually blunted acid in vitro RE hydrolase activity of LX-2 cells. Accordingly, HSCs isolated from LAL-deficient mice showed RE accumulation and were virtually devoid of acidic RE hydrolase activity. In pulse-chase experiments however, LAL-deficient HSCs, similar to LX-2 cells and primary human HSCs, were not defective in degrading REs. In summary, results demonstrate that ATGL, PNPLA3, and HSL contribute to neutral RE hydrolysis of human HSCs. LAL is the major acid RE hydrolase in HSCs. Yet, LAL is not limiting for RE degradation under serum-starvation. Together, results suggest that RE breakdown of HSCs is facilitated by (a) so far unknown, non-Orlistat inhibitable RE-hydrolase(s).
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Affiliation(s)
- Carina Wagner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria
| | - Victoria Hois
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria
| | - Lisa-Maria Pusch
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria.
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstraße 31/II, A-8010 Graz, Austria; BioTechMed-Graz, Graz, Austria.
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22
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Lu S, Liu G, Chen T, Wang W, Hu J, Tang D, Peng X. Lentivirus-Mediated hFGF21 Stable Expression in Liver of Diabetic Rats Model and Its Antidiabetic Effect Observation. Hum Gene Ther 2020; 31:472-484. [PMID: 32027183 DOI: 10.1089/hum.2019.322] [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] [Indexed: 11/12/2022] Open
Abstract
The incidence of type 2 diabetes mellitus (T2DM) has been increasing annually, which is a serious threat to human health. Fibroblast growth factor 21 (FGF21) is one of the most popular targets for the treatment of diabetes because it effectively improves glycolipid metabolism. In our experiment, human FGF21 (hFGF21) was injected and stably expressed in the liver tissues of a rat T2DM model with lentivirus system. Based on clinical and histopathological examinations, islet cells were protected and liver tissue lesions were repaired for >4 months. Glucose metabolism and histopathology were controlled perfectly when hFGF21 was stably expressed in partial liver of T2DM rats. The results showed that the liver tissue cell apoptosis was reduced, the lipid droplet content was decreased, the oxidative stress indexes were improved, the glycogen content was increased, and the islet cells were increased too. Besides, insulin sensitivity and glycogen synthesis-related genes expression were increased, but cell apoptosis-related genes caspase3 and NFκB expression were decreased. The effectiveness of results suggested that injecting hFGF21 to rats liver could effectively treat T2DM.
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Affiliation(s)
- Shuaiyao Lu
- Institute of Medical Biology, Peking Union Medical College, Chinese Academy of Medical Sciences, Kunming, China
- State Key Laboratory of Medical Molecular Biology, Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Medical Primate Research Center, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
- Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Diseases, Kunming, China
| | - Guanglong Liu
- The First People's Hospital of Yunnan Province, Kunming, China
| | - Tianxing Chen
- The First People's Hospital of Yunnan Province, Kunming, China
| | - Wanpu Wang
- The First People's Hospital of Yunnan Province, Kunming, China
| | - Jingwen Hu
- Institute of Medical Biology, Peking Union Medical College, Chinese Academy of Medical Sciences, Kunming, China
| | - Donghong Tang
- Institute of Medical Biology, Peking Union Medical College, Chinese Academy of Medical Sciences, Kunming, China
- Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Diseases, Kunming, China
| | - Xiaozhong Peng
- Institute of Medical Biology, Peking Union Medical College, Chinese Academy of Medical Sciences, Kunming, China
- State Key Laboratory of Medical Molecular Biology, Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Medical Primate Research Center, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
- Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Diseases, Kunming, China
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23
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Ma Y, Zhang M, Yu H, Lu J, Cheng KKY, Zhou J, Chen H, Jia W. Activation of G0/G1 switch gene 2 by endoplasmic reticulum stress enhances hepatic steatosis. Metabolism 2019; 99:32-44. [PMID: 31271806 DOI: 10.1016/j.metabol.2019.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/12/2019] [Accepted: 06/28/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Perturbed endoplasmic reticulum (ER) homeostasis and increased levels of G0/G1 Switch Gene 2 (G0S2) have been documented in animal models with fatty liver disease. In this study, we investigated whether G0S2 is regulated by branch of the unfolded protein response (UPR) and contributes to ER stress-induced hepatic steatosis. METHODS We first analyzed G0S2 expression and the state of the three canonical UPR branches in several hepatic steatosis models, tunicamycin-treated C57BL/6J mice and HepG2 cells, where ER homeostasis was perturbed. We pretreated HepG2 cells with tauroursodeoxycholic acid (TUDCA) to validate whether G0S2 was the downstream target of ER stress. Loss or gain function analysis was conducted to identify which UPR branch specifically linked to G0S2 transcription. The transcription mechanism was estimated by luciferase reporter assay and ChIP assay. RESULTS Here we showed that the activation of ER stress was accompanied by elevation of G0S2 expression in the occurrence of fatty liver disease. Furthermore, G0S2 was found to be a novel target gene of activating transcription factor 4(ATF4). We also localized one conserved ATF4-binding sequence in the 5' regulatory region of G0S2, which was responsible for transcriptional activating G0S2 by ATF4. CONCLUSION G0S2 is regulated by the PERK-eIF2α-ATF4 branch of the UPR and mediates ER stress-induced hepatic steatosis.
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Affiliation(s)
- Yunqin Ma
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Mingliang Zhang
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Haoyong Yu
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Junxi Lu
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Kenneth K Y Cheng
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Jian Zhou
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Haibing Chen
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Weiping Jia
- Department of Endocrinology and Metabolism, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center of Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
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24
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Haemmerle G, Lass A. Genetically modified mouse models to study hepatic neutral lipid mobilization. Biochim Biophys Acta Mol Basis Dis 2019; 1865:879-894. [PMID: 29883718 PMCID: PMC6887554 DOI: 10.1016/j.bbadis.2018.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/25/2018] [Accepted: 06/01/2018] [Indexed: 02/07/2023]
Abstract
Excessive accumulation of triacylglycerol is the common denominator of a wide range of clinical pathologies of liver diseases, termed non-alcoholic fatty liver disease. Such excessive triacylglycerol deposition in the liver is also referred to as hepatic steatosis. Although liver steatosis often resolves over time, it eventually progresses to steatohepatitis, liver fibrosis and cirrhosis, with associated complications, including liver failure, hepatocellular carcinoma and ultimately death of affected individuals. From the disease etiology it is obvious that a tight regulation between lipid uptake, triacylglycerol synthesis, hydrolysis, secretion and fatty acid oxidation is required to prevent triacylglycerol deposition in the liver. In addition to triacylglycerol, also a tight control of other neutral lipid ester classes, i.e. cholesteryl esters and retinyl esters, is crucial for the maintenance of a healthy liver. Excessive cholesteryl ester accumulation is a hallmark of cholesteryl ester storage disease or Wolman disease, which is associated with premature death. The loss of hepatic vitamin A stores (retinyl ester stores of hepatic stellate cells) is incidental to the onset of liver fibrosis. Importantly, this more advanced stage of liver disease usually does not resolve but progresses to life threatening stages, i.e. liver cirrhosis and cancer. Therefore, understanding the enzymes and pathways that mobilize hepatic neutral lipid esters is crucial for the development of strategies and therapies to ameliorate pathophysiological conditions associated with derangements of hepatic neutral lipid ester stores, including liver steatosis, steatohepatitis, and fibrosis. This review highlights the physiological roles of enzymes governing the mobilization of neutral lipid esters at different sites in liver cells, including cytosolic lipid droplets, endoplasmic reticulum, and lysosomes. This article is part of a Special Issue entitled Molecular Basis of Disease: Animal models in liver disease.
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Affiliation(s)
- Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31/II, 8010 Graz, Austria.
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Heinrichstraße 31/II, 8010 Graz, Austria; BioTechMed-Graz, Austria.
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25
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Pajed L, Wagner C, Taschler U, Schreiber R, Kolleritsch S, Fawzy N, Pototschnig I, Schoiswohl G, Pusch LM, Wieser BI, Vesely P, Hoefler G, Eichmann TO, Zimmermann R, Lass A. Hepatocyte-specific deletion of lysosomal acid lipase leads to cholesteryl ester but not triglyceride or retinyl ester accumulation. J Biol Chem 2019; 294:9118-9133. [PMID: 31023823 PMCID: PMC6556574 DOI: 10.1074/jbc.ra118.007201] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/23/2019] [Indexed: 12/22/2022] Open
Abstract
Lysosomal acid lipase (LAL) hydrolyzes cholesteryl ester (CE) and retinyl ester (RE) and triglyceride (TG). Mice globally lacking LAL accumulate CE most prominently in the liver. The severity of the CE accumulation phenotype progresses with age and is accompanied by hepatomegaly and hepatic cholesterol crystal deposition. In contrast, hepatic TG accumulation is much less pronounced in these mice, and hepatic RE levels are even decreased. To dissect the functional role of LAL for neutral lipid ester mobilization in the liver, we generated mice specifically lacking LAL in hepatocytes (hep-LAL-ko). On a standard chow diet, hep-LAL-ko mice exhibited increased hepatic CE accumulation but unaltered TG and RE levels. Feeding the hep-LAL-ko mice a vitamin A excess/high-fat diet (VitA/HFD) further increased hepatic cholesterol levels, but hepatic TG and RE levels in these mice were lower than in control mice. Performing in vitro activity assays with lysosome-enriched fractions from livers of mice globally lacking LAL, we detected residual acid hydrolytic activities against TG and RE. Interestingly, this non-LAL acid TG hydrolytic activity was elevated in lysosome-enriched fractions from livers of hep-LAL-ko mice upon VitA/HFD feeding. In conclusion, the neutral lipid ester phenotype in livers from hep-LAL-ko mice indicates that LAL is limiting for CE turnover, but not for TG and RE turnovers. Furthermore, in vitro hydrolase activity assays revealed the existence of non-LAL acid hydrolytic activities for TG and RE. The corresponding acid lipase(s) catalyzing these reactions remains to be identified.
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Affiliation(s)
- Laura Pajed
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Carina Wagner
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Ulrike Taschler
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Renate Schreiber
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Stephanie Kolleritsch
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Nermeen Fawzy
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Isabella Pototschnig
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Gabriele Schoiswohl
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Lisa-Maria Pusch
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II
| | - Beatrix I Wieser
- the Diagnostic and Research Center for Molecular BioMedicine, Institute of Pathology, Medical University of Graz
| | - Paul Vesely
- the Diagnostic and Research Center for Molecular BioMedicine, Institute of Pathology, Medical University of Graz
| | - Gerald Hoefler
- the Diagnostic and Research Center for Molecular BioMedicine, Institute of Pathology, Medical University of Graz.,BioTechMed-Graz, 8010 Graz, Austria
| | - Thomas O Eichmann
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II.,the Center for Explorative Lipidomics, BioTechMed-Graz, and
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II.,BioTechMed-Graz, 8010 Graz, Austria
| | - Achim Lass
- From the Institute of Molecular Biosciences, NAWI Graz, University of Graz, Heinrichstrasse 31/II, .,BioTechMed-Graz, 8010 Graz, Austria
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26
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Of mice and men: The physiological role of adipose triglyceride lipase (ATGL). Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:880-899. [PMID: 30367950 PMCID: PMC6439276 DOI: 10.1016/j.bbalip.2018.10.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/12/2022]
Abstract
Adipose triglyceride lipase (ATGL) has been discovered 14 years ago and revised our view on intracellular triglyceride (TG) mobilization – a process termed lipolysis. ATGL initiates the hydrolysis of TGs to release fatty acids (FAs) that are crucial energy substrates, precursors for the synthesis of membrane lipids, and ligands of nuclear receptors. Thus, ATGL is a key enzyme in whole-body energy homeostasis. In this review, we give an update on how ATGL is regulated on the transcriptional and post-transcriptional level and how this affects the enzymes' activity in the context of neutral lipid catabolism. In depth, we highlight and discuss the numerous physiological functions of ATGL in lipid and energy metabolism. Over more than a decade, different genetic mouse models lacking or overexpressing ATGL in a cell- or tissue-specific manner have been generated and characterized. Moreover, pharmacological studies became available due to the development of a specific murine ATGL inhibitor (Atglistatin®). The identification of patients with mutations in the human gene encoding ATGL and their disease spectrum has underpinned the importance of ATGL in humans. Together, mouse models and human data have advanced our understanding of the physiological role of ATGL in lipid and energy metabolism in adipose and non-adipose tissues, and of the pathophysiological consequences of ATGL dysfunction in mice and men. Summary of mouse models with genetic or pharmacological manipulation of ATGL. Summary of patients with mutations in the human gene encoding ATGL. In depth discussion of the role of ATGL in numerous physiological processes in mice and men.
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27
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Régnier M, Polizzi A, Lippi Y, Fouché E, Michel G, Lukowicz C, Smati S, Marrot A, Lasserre F, Naylies C, Batut A, Viars F, Bertrand-Michel J, Postic C, Loiseau N, Wahli W, Guillou H, Montagner A. Insights into the role of hepatocyte PPARα activity in response to fasting. Mol Cell Endocrinol 2018; 471:75-88. [PMID: 28774777 DOI: 10.1016/j.mce.2017.07.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/04/2017] [Accepted: 07/28/2017] [Indexed: 12/28/2022]
Abstract
The liver plays a central role in the regulation of fatty acid metabolism. Hepatocytes are highly sensitive to nutrients and hormones that drive extensive transcriptional responses. Nuclear hormone receptors are key transcription factors involved in this process. Among these factors, PPARα is a critical regulator of hepatic lipid catabolism during fasting. This study aimed to analyse the wide array of hepatic PPARα-dependent transcriptional responses during fasting. We compared gene expression in male mice with a hepatocyte specific deletion of PPARα and their wild-type littermates in the fed (ad libitum) and 24-h fasted states. Liver samples were acquired, and transcriptome and lipidome analyses were performed. Our data extended and confirmed the critical role of hepatocyte PPARα as a central for regulator of gene expression during starvation. Interestingly, we identified novel PPARα-sensitive genes, including Cxcl-10, Rab30, and Krt23. We also found that liver phospholipid remodelling was a novel fasting-sensitive pathway regulated by PPARα. These results may contribute to investigations on transcriptional control in hepatic physiology and underscore the clinical relevance of drugs that target PPARα in liver pathologies, such as non-alcoholic fatty liver disease.
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Affiliation(s)
- Marion Régnier
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Arnaud Polizzi
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Yannick Lippi
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Edwin Fouché
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Géraldine Michel
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Céline Lukowicz
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Sarra Smati
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France; Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Alain Marrot
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Frédéric Lasserre
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Claire Naylies
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Aurélie Batut
- Metatoul-Lipidomic Facility, MetaboHUB, Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Fanny Viars
- Metatoul-Lipidomic Facility, MetaboHUB, Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Justine Bertrand-Michel
- Metatoul-Lipidomic Facility, MetaboHUB, Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
| | - Catherine Postic
- Institut National de La Santé et de La Recherche Médicale (INSERM), U1016, Institut Cochin, Paris, France
| | - Nicolas Loiseau
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France
| | - Walter Wahli
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France; Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, 11 Mandalay Road, 308232, Singapore; Center for Integrative Genomics, Université de Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - Hervé Guillou
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France.
| | - Alexandra Montagner
- Institut National de La Recherche Agronomique (INRA), UMR1331 ToxAlim, Toulouse, France; Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.
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28
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Iroz A, Montagner A, Benhamed F, Levavasseur F, Polizzi A, Anthony E, Régnier M, Fouché E, Lukowicz C, Cauzac M, Tournier E, Do-Cruzeiro M, Daujat-Chavanieu M, Gerbal-Chalouin S, Fauveau V, Marmier S, Burnol AF, Guilmeau S, Lippi Y, Girard J, Wahli W, Dentin R, Guillou H, Postic C. A Specific ChREBP and PPARα Cross-Talk Is Required for the Glucose-Mediated FGF21 Response. Cell Rep 2018; 21:403-416. [PMID: 29020627 PMCID: PMC5643524 DOI: 10.1016/j.celrep.2017.09.065] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 08/15/2017] [Accepted: 09/20/2017] [Indexed: 02/03/2023] Open
Abstract
While the physiological benefits of the fibroblast growth factor 21 (FGF21) hepatokine are documented in response to fasting, little information is available on Fgf21 regulation in a glucose-overload context. We report that peroxisome-proliferator-activated receptor α (PPARα), a nuclear receptor of the fasting response, is required with the carbohydrate-sensitive transcription factor carbohydrate-responsive element-binding protein (ChREBP) to balance FGF21 glucose response. Microarray analysis indicated that only a few hepatic genes respond to fasting and glucose similarly to Fgf21. Glucose-challenged Chrebp−/− mice exhibit a marked reduction in FGF21 production, a decrease that was rescued by re-expression of an active ChREBP isoform in the liver of Chrebp−/− mice. Unexpectedly, carbohydrate challenge of hepatic Pparα knockout mice also demonstrated a PPARα-dependent glucose response for Fgf21 that was associated with an increased sucrose preference. This blunted response was due to decreased Fgf21 promoter accessibility and diminished ChREBP binding onto Fgf21 carbohydrate-responsive element (ChoRE) in hepatocytes lacking PPARα. Our study reports that PPARα is required for the ChREBP-induced glucose response of FGF21. Fgf21 is a unique hepatic gene inducible by both catabolic and anabolic signals The ChREBP-mediated induction of Fgf21 in hepatocytes requires PPARα Loss of PPARα impairs Fgf21 promoter accessibility at the ChoRE PPARα is required for the control of sucrose preference in vivo
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Affiliation(s)
- Alison Iroz
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Alexandra Montagner
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Fadila Benhamed
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Françoise Levavasseur
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Arnaud Polizzi
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Elodie Anthony
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Marion Régnier
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Edwin Fouché
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Céline Lukowicz
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Michèle Cauzac
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Emilie Tournier
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Marcio Do-Cruzeiro
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Martine Daujat-Chavanieu
- INSERM, U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, France; Université de Montpellier, UMR 1183, Montpellier, France; CHU Montpellier, Institute for Regenerative Medicine and Biotherapy, Montpellier, France
| | - Sabine Gerbal-Chalouin
- INSERM, U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, France; Université de Montpellier, UMR 1183, Montpellier, France; CHU Montpellier, Institute for Regenerative Medicine and Biotherapy, Montpellier, France
| | - Véronique Fauveau
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Solenne Marmier
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Anne-Françoise Burnol
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Sandra Guilmeau
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Yannick Lippi
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France
| | - Jean Girard
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France
| | - Walter Wahli
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore; Center for Integrative Genomics, University of Lausanne, Genopode Building, Lausanne 1015, Switzerland
| | - Renaud Dentin
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France.
| | - Hervé Guillou
- Toxalim, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse 31027, France.
| | - Catherine Postic
- INSERM U1016, Institut Cochin, Paris 75014, France; CNRS UMR 8104, Paris 75014, France; University of Paris Descartes, Sorbonne Paris Cité, Paris 75005, France.
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29
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Zhao N, Li X, Feng Y, Han J, Feng Z, Li X, Wen Y. The Nuclear Orphan Receptor Nur77 Alleviates Palmitate-induced Fat Accumulation by Down-regulating G0S2 in HepG2 Cells. Sci Rep 2018; 8:4809. [PMID: 29556076 PMCID: PMC5859288 DOI: 10.1038/s41598-018-23141-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 03/07/2018] [Indexed: 12/11/2022] Open
Abstract
Excessive triglyceride accumulation in hepatocytes is the hallmark of obesity-associated nonalcoholic fatty liver disease (NAFLD). Elevated levels of the saturated free fatty acid palmitate in obesity are a major contributor to excessive hepatic lipid accumulation. The nuclear orphan receptor Nur77 is a transcriptional regulator and a lipotoxicity sensor. Using human HepG2 hepatoma cells, this study aimed to investigate the functional role of Nur77 in palmitate-induced hepatic steatosis. The results revealed that palmitate significantly induced lipid accumulation and suppressed lipolysis in hepatocytes. In addition, palmitate significantly suppressed Nur77 expression and stimulated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and its target genes. Nur77 overexpression significantly reduced palmitate-induced expression of PPARγ and its target genes. Moreover, Nur77 overexpression attenuated lipid accumulation and augmented lipolysis in palmitate-treated hepatocytes. Importantly, G0S2 knockdown significantly attenuated lipid accumulation and augmented lipolysis in palmitate-treated hepatocytes, whereas G0S2 knockdown had no effect on the palmitate-induced expression of Nur77, PPARγ, or PPARγ target genes. In summary, palmitate suppresses Nur77 expression in HepG2 cells, and Nur77 overexpression alleviates palmitate-induced hepatic fat accumulation by down-regulating G0S2. These results display a novel molecular mechanism linking Nur77-regulated G0S2 expression to palmitate-induced hepatic steatosis.
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Affiliation(s)
- Naiqian Zhao
- Department of Gerontology, Second Hospital of Shanxi Medical University, 382 Wuyi Road, Taiyuan, 030001, Shanxi, China.
| | - Xiaoyan Li
- Department of Infectious Diseases, First People's Hospital of Jinzhong, 85 Shuncheng Street, Jinzhong, 030600, Shanxi, China
| | - Ying Feng
- Department of Gerontology, Second Hospital of Shanxi Medical University, 382 Wuyi Road, Taiyuan, 030001, Shanxi, China
| | - Jinxiang Han
- Department of Gerontology, Second Hospital of Shanxi Medical University, 382 Wuyi Road, Taiyuan, 030001, Shanxi, China
| | - Ziling Feng
- Department of Infectious Diseases, First People's Hospital of Jinzhong, 85 Shuncheng Street, Jinzhong, 030600, Shanxi, China
| | - Xifeng Li
- Department of Infectious Diseases, First People's Hospital of Jinzhong, 85 Shuncheng Street, Jinzhong, 030600, Shanxi, China
| | - Yanfang Wen
- Department of Infectious Diseases, First People's Hospital of Jinzhong, 85 Shuncheng Street, Jinzhong, 030600, Shanxi, China
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30
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Zhao NQ, Li XY, Wang L, Feng ZL, Li XF, Wen YF, Han JX. Palmitate induces fat accumulation by activating C/EBPβ-mediated G0S2 expression in HepG2 cells. World J Gastroenterol 2017; 23:7705-7715. [PMID: 29209111 PMCID: PMC5703930 DOI: 10.3748/wjg.v23.i43.7705] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/27/2017] [Accepted: 09/28/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To determine the role of G0/G1 switch gene 2 (G0S2) and its transcriptional regulation in palmitate-induced hepatic lipid accumulation.
METHODS HepG2 cells were treated with palmitate, or palmitate in combination with CCAAT/enhancer binding protein (C/EBP)β siRNA or G0S2 siRNA. The mRNA expression of C/EBPβ, peroxisome proliferator-activated receptor (PPAR)γ and PPARγ target genes (G0S2, GPR81, GPR109A and Adipoq) was examined by qPCR. The protein expression of C/EBPβ, PPARγ, and G0S2 was determined by Western blotting. Lipid accumulation was detected with Oil Red O staining and quantified by absorbance value of the extracted Oil Red O dye. Lipolysis was evaluated by measuring the amount of glycerol released into the medium.
RESULTS Palmitate caused a dose-dependent increase in lipid accumulation and a dose-dependent decrease in lipolysis in HepG2 cells. In addition, palmitate increased the mRNA expression of C/EBPβ, PPARγ, and PPARγ target genes (G0S2, GPR81, GPR109A, and Adipoq) and the protein expression of C/EBPβ, PPARγ, and G0S2 in a dose-dependent manner. Knockdown of C/EBPβ decreased palmitate-induced PPARγ and its target genes (G0S2, GPR81, GPR109A, and Adipoq) mRNA expression and palmitate-induced PPARγ and G0S2 protein expression in HepG2 cells. Knockdown of C/EBPβ also attenuated lipid accumulation and augmented lipolysis in palmitate-treated HepG2 cells. G0S2 knockdown attenuated lipid accumulation and augmented lipolysis, while G0S2 knockdown had no effects on the mRNA expression of C/EBPβ, PPARγ, and PPARγ target genes (GPR81, GPR109A and Adipoq) in palmitate-treated HepG2 cells.
CONCLUSION Palmitate can induce lipid accumulation in HepG2 cells by activating C/EBPβ-mediated G0S2 expression.
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Affiliation(s)
- Nai-Qian Zhao
- Department of Gerontology, the Second Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi Province, China
| | - Xiao-Yan Li
- Department of Infectious Diseases, the First People’s Hospital of Jinzhong, Jinzhong 030600, Shanxi Province, China
| | - Li Wang
- Department of Gerontology, the Second Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi Province, China
| | - Zi-Ling Feng
- Department of Infectious Diseases, the First People’s Hospital of Jinzhong, Jinzhong 030600, Shanxi Province, China
| | - Xi-Fen Li
- Department of Infectious Diseases, the First People’s Hospital of Jinzhong, Jinzhong 030600, Shanxi Province, China
| | - Yan-Fang Wen
- Department of Infectious Diseases, the First People’s Hospital of Jinzhong, Jinzhong 030600, Shanxi Province, China
| | - Jin-Xiang Han
- Department of Gerontology, the Second Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi Province, China
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31
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Soares AF, Duarte JMN, Gruetter R. Increased hepatic fatty acid polyunsaturation precedes ectopic lipid deposition in the liver in adaptation to high-fat diets in mice. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 31:341-354. [PMID: 29027041 DOI: 10.1007/s10334-017-0654-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVE We monitored hepatic lipid content (HLC) and fatty acid (FA) composition in the context of enhanced lipid handling induced by a metabolic high-fat diet (HFD) challenge and fasting. MATERIALS AND METHODS Mice received a control diet (10% of kilocalories from fat, N = 14) or an HFD (45% or 60% of kilocalories from fat, N = 10 and N = 16, respectively) for 26 weeks. A subset of five mice receiving an HFD (60% of kilocalories from fat) were switched to the control diet for the final 7 weeks. At nine time points, magnetic resonance spectroscopy was performed in vivo at 14.1 T, interleaved with glucose tolerance tests. RESULTS Glucose intolerance promptly developed with the HFD, followed by a progressive increase of fasting insulin level, simultaneously with that of HLC. These metabolic defects were normalized by dietary reversal. HFD feeding immediately increased polyunsaturation of hepatic FA, before lipid accumulation. Fasting-induced changes in hepatic lipids (increased HLC and FA polyunsaturation, decreased FA monounsaturation) in control-diet-fed mice were not completely reproduced in HFD-fed mice, not even after dietary reversal. CONCLUSION A similar adaptation of hepatic lipids to both fasting and an HFD suggests common mechanisms of lipid trafficking from adipose tissue to the liver. Altered hepatic lipid handling with fasting indicates imperfect metabolic recovery from HFD exposure.
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Affiliation(s)
- Ana Francisca Soares
- Laboratory for Functional and Metabolic Imaging, Swiss Federal Institute of Technology, Bâtiment CH, Station 6, 1015, Lausanne, Switzerland.
| | - João M N Duarte
- Laboratory for Functional and Metabolic Imaging, Swiss Federal Institute of Technology, Bâtiment CH, Station 6, 1015, Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging, Swiss Federal Institute of Technology, Bâtiment CH, Station 6, 1015, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland.,Department of Radiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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32
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Zechner R, Madeo F, Kratky D. Cytosolic lipolysis and lipophagy: two sides of the same coin. Nat Rev Mol Cell Biol 2017; 18:671-684. [DOI: 10.1038/nrm.2017.76] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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33
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Caputo T, Gilardi F, Desvergne B. From chronic overnutrition to metaflammation and insulin resistance: adipose tissue and liver contributions. FEBS Lett 2017; 591:3061-3088. [DOI: 10.1002/1873-3468.12742] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/28/2017] [Accepted: 07/02/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Tiziana Caputo
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
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34
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Zhang X, Heckmann BL, Campbell LE, Liu J. G0S2: A small giant controller of lipolysis and adipose-liver fatty acid flux. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28645852 DOI: 10.1016/j.bbalip.2017.06.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The discovery of adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) provided a major paradigm shift in the understanding of intracellular lipolysis in both adipocytes and nonadipocyte cells. The subsequent discovery of G0/G1 switch gene 2 (G0S2) as a potent endogenous inhibitor of ATGL revealed a unique mechanism governing lipolysis and fatty acid (FA) availability. G0S2 is highly conserved in vertebrates, and exhibits cyclical expression pattern between adipose tissue and liver that is critical to lipid flux and energy homeostasis in these two tissues. Biochemical and cell biological studies have demonstrated that a direct interaction with ATGL mediates G0S2's inhibitory effects on lipolysis and lipid droplet degradation. In this review we examine evidence obtained from recent in vitro and in vivo studies that lends support to the proof-of-principle concept that G0S2 functions as a master regulator of tissue-specific balance of TG storage vs. mobilization, partitioning of metabolic fuels between adipose and liver, and the whole-body adaptive energy response. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Xiaodong Zhang
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, AZ, United States; HEAL(th) Program, Mayo Clinic, Scottsdale, AZ, United States
| | - Bradlee L Heckmann
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Latoya E Campbell
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Jun Liu
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, AZ, United States; HEAL(th) Program, Mayo Clinic, Scottsdale, AZ, United States; Division of Endocrinology, Mayo Clinic, Scottsdale, AZ, United States.
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35
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Schweiger M, Romauch M, Schreiber R, Grabner GF, Hütter S, Kotzbeck P, Benedikt P, Eichmann TO, Yamada S, Knittelfelder O, Diwoky C, Doler C, Mayer N, De Cecco W, Breinbauer R, Zimmermann R, Zechner R. Pharmacological inhibition of adipose triglyceride lipase corrects high-fat diet-induced insulin resistance and hepatosteatosis in mice. Nat Commun 2017; 8:14859. [PMID: 28327588 PMCID: PMC5364409 DOI: 10.1038/ncomms14859] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 02/06/2017] [Indexed: 12/19/2022] Open
Abstract
Elevated circulating fatty acids (FAs) contribute to the development of obesity-associated metabolic complications such as insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). Hence, reducing adipose tissue lipolysis to diminish the mobilization of FAs and lower their respective plasma concentrations represents a potential treatment strategy to counteract obesity-associated disorders. Here we show that specific inhibition of adipose triglyceride lipase (Atgl) with the chemical inhibitor, Atglistatin, effectively reduces adipose tissue lipolysis, weight gain, IR and NAFLD in mice fed a high-fat diet. Importantly, even long-term treatment does not lead to lipid accumulation in ectopic tissues such as the skeletal muscle or heart. Thus, the severe cardiac steatosis and cardiomyopathy that is observed in genetic models of Atgl deficiency does not occur in Atglistatin-treated mice. Our data validate the pharmacological inhibition of Atgl as a potentially powerful therapeutic strategy to treat obesity and associated metabolic disorders. The enzyme Atgl participates in the breakdown of lipids in adipose tissue. Here the authors show that pharmacological inhibition of Atgl reduces weight gain and improves metabolic health in mice fed a high-fat diet, without causing adverse effects in cardiac muscle associated with genetic depletion of Atgl.
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Affiliation(s)
- Martina Schweiger
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Matthias Romauch
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Sabrina Hütter
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Petra Kotzbeck
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Pia Benedikt
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Sohsuke Yamada
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Oskar Knittelfelder
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Clemens Diwoky
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Carina Doler
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Nicole Mayer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Werner De Cecco
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Rolf Breinbauer
- Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
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36
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Heckmann BL, Zhang X, Saarinen AM, Schoiswohl G, Kershaw EE, Zechner R, Liu J. Liver X receptor α mediates hepatic triglyceride accumulation through upregulation of G0/G1 Switch Gene 2 expression. JCI Insight 2017; 2:e88735. [PMID: 28239648 DOI: 10.1172/jci.insight.88735] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Liver X receptors (LXRs) are transcription factors essential for cholesterol homeostasis and lipogenesis. LXRα has been implicated in regulating hepatic triglyceride (TG) accumulation upon both influx of adipose-derived fatty acids (FAs) during fasting and stimulation of de novo FA synthesis by chemical agonism of LXR. However, whether or not a convergent mechanism is employed to drive deposition of FAs from these 2 different sources in TGs is undetermined. Here, we report that the G0/G1 Switch Gene 2 (G0S2), a selective inhibitor of intracellular TG hydrolysis/lipolysis, is a direct target gene of LXRα. Transcriptional activation is conferred by LXRα binding to a direct repeat 4 (DR4) motif in the G0S2 promoter. While LXRα-/- mice exhibited decreased hepatic G0S2 expression, adenoviral expression of G0S2 was sufficient to restore fasting-induced TG storage and glycogen depletion in the liver of these mice. In response to LXR agonist T0901317, G0S2 ablation prevented hepatic steatosis and hypertriglyceridemia without affecting the beneficial effects on HDL. Thus, the LXRα-G0S2 axis plays a distinct role in regulating hepatic TG during both fasting and pharmacological activation of LXR.
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Affiliation(s)
- Bradlee L Heckmann
- Department of Biochemistry and Molecular Biology.,HEALth Program, Mayo Clinic in Arizona, Scottsdale, Arizona, USA.,Mayo Graduate School, Rochester, Minnesota, USA
| | - Xiaodong Zhang
- Department of Biochemistry and Molecular Biology.,HEALth Program, Mayo Clinic in Arizona, Scottsdale, Arizona, USA
| | - Alicia M Saarinen
- Department of Biochemistry and Molecular Biology.,HEALth Program, Mayo Clinic in Arizona, Scottsdale, Arizona, USA
| | - Gabriele Schoiswohl
- Division of Endocrinology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Erin E Kershaw
- Division of Endocrinology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jun Liu
- Department of Biochemistry and Molecular Biology.,HEALth Program, Mayo Clinic in Arizona, Scottsdale, Arizona, USA.,Division of Endocrinology, Mayo Clinic in Arizona, Scottsdale, Arizona, USA
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37
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Mueller KM, Hartmann K, Kaltenecker D, Vettorazzi S, Bauer M, Mauser L, Amann S, Jall S, Fischer K, Esterbauer H, Müller TD, Tschöp MH, Magnes C, Haybaeck J, Scherer T, Bordag N, Tuckermann JP, Moriggl R. Adipocyte Glucocorticoid Receptor Deficiency Attenuates Aging- and HFD-Induced Obesity and Impairs the Feeding-Fasting Transition. Diabetes 2017; 66:272-286. [PMID: 27650854 DOI: 10.2337/db16-0381] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/14/2016] [Indexed: 11/13/2022]
Abstract
Glucocorticoids (GCs) are important regulators of systemic energy metabolism, and aberrant GC action is linked to metabolic dysfunctions. Yet, the extent to which normal and pathophysiological energy metabolism depend on the GC receptor (GR) in adipocytes remains unclear. Here, we demonstrate that adipocyte GR deficiency in mice significantly impacts systemic metabolism in different energetic states. Plasma metabolomics and biochemical analyses revealed a marked global effect of GR deficiency on systemic metabolite abundance and, thus, substrate partitioning in fed and fasted states. This correlated with a decreased lipolytic capacity of GR-deficient adipocytes under postabsorptive and fasting conditions, resulting from impaired signal transduction from β-adrenergic receptors to adenylate cyclase. Upon prolonged fasting, the impaired lipolytic response resulted in abnormal substrate utilization and lean mass wasting. Conversely, GR deficiency attenuated aging-/diet-associated obesity, adipocyte hypertrophy, and liver steatosis. Systemic glucose tolerance was improved in obese GR-deficient mice, which was associated with increased insulin signaling in muscle and adipose tissue. We conclude that the GR in adipocytes exerts central but diverging roles in the regulation of metabolic homeostasis depending on the energetic state. The adipocyte GR is indispensable for the feeding-fasting transition but also promotes adiposity and associated metabolic disorders in fat-fed and aged mice.
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Affiliation(s)
- Kristina M Mueller
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Kerstin Hartmann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | | | - Sabine Vettorazzi
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Mandy Bauer
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Lea Mauser
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Sabine Amann
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Sigrid Jall
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Katrin Fischer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Christoph Magnes
- HEALTH Institute for Biomedicine and Health Sciences, JOANNEUM RESEARCH, Forschungsgesellschaft mbH, Graz, Austria
| | | | - Thomas Scherer
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Natalie Bordag
- Center for Biomarker Research in Medicine, CBmed GmbH, Graz, Austria
| | - Jan P Tuckermann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Richard Moriggl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
- Medical University of Vienna, Vienna, Austria
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38
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Grond S, Eichmann TO, Dubrac S, Kolb D, Schmuth M, Fischer J, Crumrine D, Elias PM, Haemmerle G, Zechner R, Lass A, Radner FPW. PNPLA1 Deficiency in Mice and Humans Leads to a Defect in the Synthesis of Omega-O-Acylceramides. J Invest Dermatol 2016; 137:394-402. [PMID: 27751867 DOI: 10.1016/j.jid.2016.08.036] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 01/22/2023]
Abstract
Mutations in PNPLA1 have been identified as causative for autosomal recessive congenital ichthyosis in humans and dogs. So far, the underlying molecular mechanisms are unknown. In this study, we generated and characterized PNPLA1-deficient mice and found that PNPLA1 is crucial for epidermal sphingolipid synthesis. The absence of functional PNPLA1 in mice impaired the formation of omega-O-acylceramides and led to an accumulation of nonesterified omega-hydroxy-ceramides. As a consequence, PNPLA1-deficient mice lacked a functional corneocyte-bound lipid envelope leading to a severe skin barrier defect and premature death of newborn animals. Functional analyses of differentiated keratinocytes from a patient with mutated PNPLA1 demonstrated an identical defect in omega-O-acylceramide synthesis in human cells, indicating that PNPLA1 function is conserved among mammals and indispensable for normal skin physiology. Notably, topical application of epidermal lipids from wild-type onto Pnpla1-mutant mice promoted rebuilding of the corneocyte-bound lipid envelope, indicating that supplementation of ichthyotic skin with omega-O-acylceramides might be a therapeutic approach for the treatment of skin symptoms in individuals affected by omega-O-acylceramide deficiency.
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Affiliation(s)
- Susanne Grond
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Sandrine Dubrac
- Department of Dermatology, Venerology, and Allergology, Innsbruck Medical University, Innsbruck, Austria
| | - Dagmar Kolb
- ZMF, Center for Medical Research, Medical University of Graz, Graz, Austria; Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Matthias Schmuth
- Department of Dermatology, Venerology, and Allergology, Innsbruck Medical University, Innsbruck, Austria
| | - Judith Fischer
- Institute for Human Genetics, University Medical Center Freiburg, Freiburg i. Br., Germany
| | - Debra Crumrine
- Dermatology Service, Department of Veterans Affairs Medical Center, University of California, San Francisco, California, USA
| | - Peter M Elias
- Dermatology Service, Department of Veterans Affairs Medical Center, University of California, San Francisco, California, USA
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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39
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Montagner A, Polizzi A, Fouché E, Ducheix S, Lippi Y, Lasserre F, Barquissau V, Régnier M, Lukowicz C, Benhamed F, Iroz A, Bertrand-Michel J, Al Saati T, Cano P, Mselli-Lakhal L, Mithieux G, Rajas F, Lagarrigue S, Pineau T, Loiseau N, Postic C, Langin D, Wahli W, Guillou H. Liver PPARα is crucial for whole-body fatty acid homeostasis and is protective against NAFLD. Gut 2016; 65:1202-14. [PMID: 26838599 PMCID: PMC4941147 DOI: 10.1136/gutjnl-2015-310798] [Citation(s) in RCA: 480] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 01/04/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor expressed in tissues with high oxidative activity that plays a central role in metabolism. In this work, we investigated the effect of hepatocyte PPARα on non-alcoholic fatty liver disease (NAFLD). DESIGN We constructed a novel hepatocyte-specific PPARα knockout (Pparα(hep-/-)) mouse model. Using this novel model, we performed transcriptomic analysis following fenofibrate treatment. Next, we investigated which physiological challenges impact on PPARα. Moreover, we measured the contribution of hepatocytic PPARα activity to whole-body metabolism and fibroblast growth factor 21 production during fasting. Finally, we determined the influence of hepatocyte-specific PPARα deficiency in different models of steatosis and during ageing. RESULTS Hepatocyte PPARα deletion impaired fatty acid catabolism, resulting in hepatic lipid accumulation during fasting and in two preclinical models of steatosis. Fasting mice showed acute PPARα-dependent hepatocyte activity during early night, with correspondingly increased circulating free fatty acids, which could be further stimulated by adipocyte lipolysis. Fasting led to mild hypoglycaemia and hypothermia in Pparα(hep-/-) mice when compared with Pparα(-/-) mice implying a role of PPARα activity in non-hepatic tissues. In agreement with this observation, Pparα(-/-) mice became overweight during ageing while Pparα(hep-/-) remained lean. However, like Pparα(-/-) mice, Pparα(hep-/-) fed a standard diet developed hepatic steatosis in ageing. CONCLUSIONS Altogether, these findings underscore the potential of hepatocyte PPARα as a drug target for NAFLD.
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Affiliation(s)
| | - Arnaud Polizzi
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Edwin Fouché
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Simon Ducheix
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Yannick Lippi
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | | | - Valentin Barquissau
- INSERM UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
- University of Toulouse, UMR1048, Paul Sabatier University, France
| | - Marion Régnier
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Céline Lukowicz
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Fadila Benhamed
- INSERM U1016, Cochin Institute, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Alison Iroz
- INSERM U1016, Cochin Institute, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Justine Bertrand-Michel
- INSERM UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
- University of Toulouse, UMR1048, Paul Sabatier University, France
| | - Talal Al Saati
- INSERM/UPS-US006/CREFRE, Service d'Histopathologie, CHU Purpan, Toulouse, France
| | - Patricia Cano
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | | | | | | | - Sandrine Lagarrigue
- INRA UMR1348 Pegase, Saint-Gilles, France
- Agrocampus Ouest, UMR1348 Pegase, Rennes, France
- Université Européenne de Bretagne, France
| | - Thierry Pineau
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Nicolas Loiseau
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
| | - Catherine Postic
- INSERM U1016, Cochin Institute, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Dominique Langin
- INSERM UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France
- University of Toulouse, UMR1048, Paul Sabatier University, France
- Laboratory of Clinical Biochemistry, Toulouse University Hospitals, Toulouse, France
| | - Walter Wahli
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Center for Integrative Genomics, University of Lausanne, Genopode Building, Lausanne, Switzerland
| | - Hervé Guillou
- INRA UMR1331, ToxAlim, University of Toulouse, Toulouse, France
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40
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CREBH-FGF21 axis improves hepatic steatosis by suppressing adipose tissue lipolysis. Sci Rep 2016; 6:27938. [PMID: 27301791 PMCID: PMC4908383 DOI: 10.1038/srep27938] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/26/2016] [Indexed: 02/07/2023] Open
Abstract
Adipose tissue lipolysis produces glycerol and nonesterified fatty acids (NEFA) that serve as energy sources during nutrient scarcity. Adipose tissue lipolysis is tightly regulated and excessive lipolysis causes hepatic steatosis, as NEFA released from adipose tissue constitutes a major source of TG in the liver of patients with nonalcoholic fatty liver diseases. Here we show that the liver-enriched transcription factor CREBH is activated by TG accumulation and induces FGF21, which suppresses adipose tissue lipolysis, ameliorating hepatic steatosis. CREBH-deficient mice developed severe hepatic steatosis due to increased adipose tissue lipolysis, when fasted or fed a high-fat low-carbohydrate ketogenic diet. FGF21 production was impaired in CREBH-deficient mice, and adenoviral overexpression of FGF21 suppressed adipose tissue lipolysis and improved hepatic steatosis in these mice. Thus, our results uncover a negative feedback loop in which CREBH regulates NEFA flux from adipose tissue to the liver via FGF21.
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41
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Cheng Y, Gao WW, Tang HMV, Deng JJ, Wong CM, Chan CP, Jin DY. β-TrCP-mediated ubiquitination and degradation of liver-enriched transcription factor CREB-H. Sci Rep 2016; 6:23938. [PMID: 27029215 PMCID: PMC4814919 DOI: 10.1038/srep23938] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 03/16/2016] [Indexed: 12/13/2022] Open
Abstract
CREB-H is an endoplasmic reticulum-resident bZIP transcription factor which critically regulates lipid homeostasis and gluconeogenesis in the liver. CREB-H is proteolytically activated by regulated intramembrane proteolysis to generate a C-terminally truncated form known as CREB-H-ΔTC, which translocates to the nucleus to activate target gene expression. CREB-H-ΔTC is a fast turnover protein but the mechanism governing its destruction was not well understood. In this study, we report on β-TrCP-dependent ubiquitination and proteasomal degradation of CREB-H-ΔTC. The degradation of CREB-H-ΔTC was mediated by lysine 48-linked polyubiquitination and could be inhibited by proteasome inhibitor. CREB-H-ΔTC physically interacted with β-TrCP, a substrate recognition subunit of the SCFβ-TrCP E3 ubiquitin ligase. Forced expression of β-TrCP increased the polyubiquitination and decreased the stability of CREB-H-ΔTC, whereas knockdown of β-TrCP had the opposite effect. An evolutionarily conserved sequence, SDSGIS, was identified in CREB-H-ΔTC, which functioned as the β-TrCP-binding motif. CREB-H-ΔTC lacking this motif was stabilized and resistant to β-TrCP-induced polyubiquitination. This motif was a phosphodegron and its phosphorylation was required for β-TrCP recognition. Furthermore, two inhibitory phosphorylation sites close to the phosphodegron were identified. Taken together, our work revealed a new intracellular signaling pathway that controls ubiquitination and degradation of the active form of CREB-H transcription factor.
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Affiliation(s)
- Yun Cheng
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong
| | - Wei-Wei Gao
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong
| | - Hei-Man Vincent Tang
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong.,Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China
| | - Jian-Jun Deng
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong.,Department of Food Science and Engineering, College of Chemical Engineering, Northwestern University, Xi'an 710069, China
| | - Chi-Ming Wong
- Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China.,Department of Medicine and State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Pokfulam, Hong Kong
| | - Chi-Ping Chan
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong.,Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China
| | - Dong-Yan Jin
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong.,State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong.,Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China
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42
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Zhang W, Bu SY, Mashek MT, O-Sullivan I, Sibai Z, Khan SA, Ilkayeva O, Newgard CB, Mashek DG, Unterman TG. Integrated Regulation of Hepatic Lipid and Glucose Metabolism by Adipose Triacylglycerol Lipase and FoxO Proteins. Cell Rep 2016; 15:349-59. [PMID: 27050511 DOI: 10.1016/j.celrep.2016.03.021] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 02/23/2016] [Accepted: 03/03/2016] [Indexed: 12/16/2022] Open
Abstract
Metabolism is a highly integrated process that is coordinately regulated between tissues and within individual cells. FoxO proteins are major targets of insulin action and contribute to the regulation of gluconeogenesis, glycolysis, and lipogenesis in the liver. However, the mechanisms by which FoxO proteins exert these diverse effects in an integrated fashion remain poorly understood. We report that FoxO proteins also exert important effects on intrahepatic lipolysis and fatty acid oxidation via the regulation of adipose triacylglycerol lipase (ATGL), which mediates the first step in lipolysis, and its inhibitor, the G0/S1 switch 2 gene (G0S2). We also find that ATGL-dependent lipolysis plays a critical role in mediating diverse effects of FoxO proteins in the liver, including effects on gluconeogenic, glycolytic, and lipogenic gene expression and metabolism. These results indicate that intrahepatic lipolysis plays a critical role in mediating and integrating the regulation of glucose and lipid metabolism downstream of FoxO proteins.
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Affiliation(s)
- Wenwei Zhang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - So Young Bu
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mara T Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - InSug O-Sullivan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Zakaria Sibai
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - Salmaan A Khan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27710, USA; Department of Pharmacology, Duke University, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27710, USA; Department of Pharmacology, Duke University, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Terry G Unterman
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Medical Research Service, Jesse Brown VA Medical Center, Chicago, IL 60612, USA.
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