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Smiles WJ, Ovens AJ, Kemp BE, Galic S, Petersen J, Oakhill JS. New developments in AMPK and mTORC1 cross-talk. Essays Biochem 2024:EBC20240007. [PMID: 38994736 DOI: 10.1042/ebc20240007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/13/2024]
Abstract
Metabolic homeostasis and the ability to link energy supply to demand are essential requirements for all living cells to grow and proliferate. Key to metabolic homeostasis in all eukaryotes are AMPK and mTORC1, two kinases that sense nutrient levels and function as counteracting regulators of catabolism (AMPK) and anabolism (mTORC1) to control cell survival, growth and proliferation. Discoveries beginning in the early 2000s revealed that AMPK and mTORC1 communicate, or cross-talk, through direct and indirect phosphorylation events to regulate the activities of each other and their shared protein substrate ULK1, the master initiator of autophagy, thereby allowing cellular metabolism to rapidly adapt to energy and nutritional state. More recent reports describe divergent mechanisms of AMPK/mTORC1 cross-talk and the elaborate means by which AMPK and mTORC1 are activated at the lysosome. Here, we provide a comprehensive overview of current understanding in this exciting area and comment on new evidence showing mTORC1 feedback extends to the level of the AMPK isoform, which is particularly pertinent for some cancers where specific AMPK isoforms are implicated in disease pathogenesis.
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Affiliation(s)
- William J Smiles
- Metabolic Signalling Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Research Program for Receptor Biochemistry and Tumour Metabolism, Department of Paediatrics, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Ashley J Ovens
- Protein Engineering in Immunity and Metabolism, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Bruce E Kemp
- Protein Chemistry and Metabolism, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
- Mary Mackillop Institute for Health Research, Australian Catholic University, Fitzroy, Vic 3065, Vic. Australia
| | - Sandra Galic
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
- Metabolic Physiology, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Janni Petersen
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
- Nutrition and Metabolism, South Australia Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - Jonathan S Oakhill
- Metabolic Signalling Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
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2
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Niu Z, Liu J, Peng H, Wu X, Zheng X, Yao S, Xu C. Dietary composition and its association with metabolic dysfunction-associated fatty liver disease among Chinese adults: A cross-sectional study. Arab J Gastroenterol 2024; 25:205-213. [PMID: 38378357 DOI: 10.1016/j.ajg.2024.02.003] [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: 11/25/2023] [Revised: 01/23/2024] [Accepted: 02/10/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND AND STUDY AIMS Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the most common cause of chronic liver disease worldwide. Diet plays a critical role in the prevention and treatment of MAFLD. Our hypothesis was that the intake of some macronutrients, vitamins, or mineral elements is associated with MAFLD. PATIENTS AND METHODS Patients with MAFLD can be diagnosed based on the evidence of hepatic steatosis and if they meet any of the three additional criteria of overweight/obesity, diabetes mellitus, or metabolic dysregulation. Diets were recorded using photographs and diaries of meals for seven consecutive days. The consumed dietary composition was compared with the recommended intake according to the China Food Composition Tables (Standard Edition) version 2019 and the Chinese Dietary Reference Intakes version 2013, and its association with MAFLD was assessed by logistical regression analyses. RESULTS A total of 229 MAFLD patients and 148 healthy controls were included in this study. MAFLD patients, compared with that by non-MAFLD participants, consumed more polyunsaturated fatty acids (PUFAs) (p < 0.001), vitamin E (p < 0.001), and iron (p = 0.008). The intake of PUFAs (OR = 1.070, 95 % CI: 1.017-1.127, p = 0.009) and vitamin E (OR = 1.100, 95 % CI: 1.018-1.190, p = 0.016) was positively associated with MAFLD. In addition, the percentages of individuals who consumed PUFAs (p = 0.006), vitamin E (p < 0.001), or iron (p = 0.046) above the recommended intake were higher among the individuals with MAFLD. Daily intake of PUFAs > 11 % (OR = 2.328, 95 % CI: 1.290-4.201, p = 0.005) and vitamin E > 14 mg (OR = 2.189, 95 % CI: 1.153-4.158, p = 0.017) was positively correlated with MAFLD. CONCLUSIONS Patients with MAFLD consumed more PUFAs, vitamin E, and iron in their daily diet. Excessive consumption of PUFAs and vitamin E might be independent risk factors for the incidence of MAFLD.
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Affiliation(s)
- Zuohu Niu
- Department of Infections, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing 100010, China
| | - Jing Liu
- Department of Gastroenterology, China-Japan Friendship Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100029, China
| | - Hongye Peng
- Graduate School, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xuan Wu
- Graduate School, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xinzhuo Zheng
- Graduate School, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Shukun Yao
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing 100029, China.
| | - Chunjun Xu
- Department of Infections, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing 100010, China.
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Allard C, Miralpeix C, López-Gambero AJ, Cota D. mTORC1 in energy expenditure: consequences for obesity. Nat Rev Endocrinol 2024; 20:239-251. [PMID: 38225400 DOI: 10.1038/s41574-023-00934-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2023] [Indexed: 01/17/2024]
Abstract
In eukaryotic cells, the mammalian target of rapamycin complex 1 (sometimes referred to as the mechanistic target of rapamycin complex 1; mTORC1) orchestrates cellular metabolism in response to environmental energy availability. As a result, at the organismal level, mTORC1 signalling regulates the intake, storage and use of energy by acting as a hub for the actions of nutrients and hormones, such as leptin and insulin, in different cell types. It is therefore unsurprising that deregulated mTORC1 signalling is associated with obesity. Strategies that increase energy expenditure offer therapeutic promise for the treatment of obesity. Here we review current evidence illustrating the critical role of mTORC1 signalling in the regulation of energy expenditure and adaptive thermogenesis through its various effects in neuronal circuits, adipose tissue and skeletal muscle. Understanding how mTORC1 signalling in one organ and cell type affects responses in other organs and cell types could be key to developing better, safer treatments targeting this pathway in obesity.
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Affiliation(s)
- Camille Allard
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | | | | | - Daniela Cota
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France.
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4
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Colella F, Ramachandran P. Adipose tissue macrophage dysfunction in human MASLD - Cause or consequence? J Hepatol 2024; 80:390-393. [PMID: 38122832 DOI: 10.1016/j.jhep.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Affiliation(s)
- Fabio Colella
- Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom
| | - Prakash Ramachandran
- Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom.
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5
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Wang T, Zhao C, Zhang J, Li S, Zhang Y, Gong Y, Zhou Y, Yan L, Zhang S, Zhang Z, Hu H, Liu A, Bai X, Zou Z. Whitening of brown adipose tissue inhibits osteogenic differentiation via secretion of S100A8/A9. iScience 2024; 27:108857. [PMID: 38303710 PMCID: PMC10830855 DOI: 10.1016/j.isci.2024.108857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/20/2023] [Accepted: 01/05/2024] [Indexed: 02/03/2024] Open
Abstract
The mechanism by which brown adipose tissue (BAT) regulates bone metabolism is unclear. Here, we reveal that BAT secretes S100A8/A9, a previously unidentified BAT adipokine (batokine), to impair bone formation. Brown adipocytes-specific knockout of Rheb (RhebBAD KO), the upstream activator of mTOR, causes BAT malfunction to inhibit osteogenesis. Rheb depletion induces NF-κB dependent S100A8/A9 secretion from brown adipocytes, but not from macrophages. In wild-type mice, age-related Rheb downregulation in BAT is associated with enhanced S100A8/A9 secretion. Either batokines from RhebBAD KO mice, or recombinant S100A8/A9, inhibits osteoblast differentiation of mesenchymal stem cells in vitro by targeting toll-like receptor 4 on their surfaces. Conversely, S100A8/A9 neutralization not only rescues the osteogenesis repressed in the RhebBAD KO mice, but also alleviates age-related osteoporosis in wild-type mice. Collectively, our data revealed an unexpected BAT-bone crosstalk driven by Rheb-S100A8/A9, uncovering S100A8/A9 as a promising target for the treatment, and potentially, prevention of osteoporosis.
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Affiliation(s)
- Ting Wang
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Chaoran Zhao
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Jiahuan Zhang
- Laboratory Medicine, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Shengfa Li
- Clinical Research Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Youming Zhang
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yan Gong
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yingyue Zhou
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Lei Yan
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Sheng Zhang
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhongmin Zhang
- Division of Spine Surgery, Department of Orthopadics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Hongling Hu
- Department of Trauma and Joint Surgery, Shunde Hospital, Southern Medical University, Foshan, China
| | - Anling Liu
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xiaochun Bai
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhipeng Zou
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
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6
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Bjorkman SH, Marti A, Jena J, García-Peña LM, Weatherford ET, Kato K, Koneru J, Chen J, Sood A, Potthoff MJ, Adams CM, Abel ED, Pereira RO. ATF4 expression in thermogenic adipocytes is required for cold-induced thermogenesis in mice via FGF21-independent mechanisms. Sci Rep 2024; 14:1563. [PMID: 38238383 PMCID: PMC10796914 DOI: 10.1038/s41598-024-52004-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024] Open
Abstract
In brown adipose tissue (BAT), short-term cold exposure induces the activating transcription factor 4 (ATF4), and its downstream target fibroblast growth factor 21 (FGF21). Induction of ATF4 in BAT in response to mitochondrial stress is required for thermoregulation, partially by increasing FGF21 expression. In the present study, we tested the hypothesis that Atf4 and Fgf21 induction in BAT are both required for BAT thermogenesis under physiological stress by generating mice selectively lacking either Atf4 (ATF4 BKO) or Fgf21 (FGF21 BKO) in UCP1-expressing adipocytes. After 3 days of cold exposure, core body temperature was significantly reduced in ad-libitum-fed ATF4 BKO mice, which correlated with Fgf21 downregulation in brown and beige adipocytes, and impaired browning of white adipose tissue. Conversely, despite having reduced browning, FGF21 BKO mice had preserved core body temperature after cold exposure. Mechanistically, ATF4, but not FGF21, regulates amino acid import and metabolism in response to cold, likely contributing to BAT thermogenic capacity under ad libitum-fed conditions. Importantly, under fasting conditions, both ATF4 and FGF21 were required for thermogenesis in cold-exposed mice. Thus, ATF4 regulates BAT thermogenesis under fed conditions likely in a FGF21-independent manner, in part via increased amino acid uptake and metabolism.
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Affiliation(s)
- Sarah H Bjorkman
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Obstetrics and Gynecology, Reproductive Endocrinology and Infertility, University of Iowa Hospital and Clinics, Iowa City, IA, USA
| | - Alex Marti
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jayashree Jena
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Luis Miguel García-Peña
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Eric T Weatherford
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Kevin Kato
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jivan Koneru
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Jason Chen
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Ayushi Sood
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
| | - Matthew J Potthoff
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Christopher M Adams
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Renata O Pereira
- Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 169 Newton Road, 4338 PBDB, Iowa City, IA, 52242, USA.
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7
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Zhang X, Ding X, Wang C, Le Q, Wu D, Song A, Huang G, Luo L, Luo Y, Yang X, Goins AE, Desai SP, Qiu C, Silva FD, Feldman LE, Zhou J, Spafford MF, Boyd NH, Prossnitz ER, Yang XO, Wang QA, Liu M. Depletion of JunB increases adipocyte thermogenic capacity and ameliorates diet-induced insulin resistance. Nat Metab 2024; 6:78-93. [PMID: 38191667 PMCID: PMC10954369 DOI: 10.1038/s42255-023-00945-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 11/10/2023] [Indexed: 01/10/2024]
Abstract
The coexistence of brown adipocytes with low and high thermogenic activity is a fundamental feature of brown adipose tissue heterogeneity and plasticity. However, the mechanisms that govern thermogenic adipocyte heterogeneity and its significance in obesity and metabolic disease remain poorly understood. Here we show that in male mice, a population of transcription factor jun-B (JunB)-enriched (JunB+) adipocytes within the brown adipose tissue exhibits lower thermogenic capacity compared to high-thermogenic adipocytes. The JunB+ adipocyte population expands in obesity. Depletion of JunB in adipocytes increases the fraction of adipocytes exhibiting high thermogenic capacity, leading to enhanced basal and cold-induced energy expenditure and protection against diet-induced obesity and insulin resistance. Mechanistically, JunB antagonizes the stimulatory effects of PPARγ coactivator-1α on high-thermogenic adipocyte formation by directly binding to the promoter of oestrogen-related receptor alpha, a PPARγ coactivator-1α downstream effector. Taken together, our study uncovers that JunB shapes thermogenic adipocyte heterogeneity, serving a critical role in maintaining systemic metabolic health.
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Affiliation(s)
- Xing Zhang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Xiaofeng Ding
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Chunqing Wang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Que Le
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Dandan Wu
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Anying Song
- Department of Molecular & Cellular Endocrinology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Guixiang Huang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, People's Republic of China
| | - Liping Luo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Yan Luo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Xin Yang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Aleyah E Goins
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Sharina P Desai
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Chengrui Qiu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Floyd D Silva
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Lily Elizabeth Feldman
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Jianlin Zhou
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, People's Republic of China
| | - Michael F Spafford
- Department of Surgery, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Nathan H Boyd
- Department of Surgery, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Eric R Prossnitz
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- UNM Comprehensive Cancer Center (UNMCCC), University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Xuexian O Yang
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Qiong A Wang
- Department of Molecular & Cellular Endocrinology, City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - Meilian Liu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
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8
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Ivanova I, Shen K. Structures and Functions of the Human GATOR1 Complex. Subcell Biochem 2024; 104:269-294. [PMID: 38963491 DOI: 10.1007/978-3-031-58843-3_12] [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: 07/05/2024]
Abstract
Eukaryotic cells coordinate available nutrients with their growth through the mechanistic target of rapamycin complex 1 (mTORC1) pathway, in which numerous evolutionarily conserved protein complexes survey and transmit nutrient inputs toward mTORC1. mTORC1 integrates these inputs and activates downstream anabolic or catabolic programs that are in tune with cellular needs, effectively maintaining metabolic homeostasis. The GAP activity toward Rags-1 (GATOR1) protein complex is a critical negative regulator of the mTORC1 pathway and, in the absence of amino acid inputs, is activated to turn off mTORC1 signaling. GATOR1-mediated inhibition of mTORC1 signaling is tightly regulated by an ensemble of protein complexes that antagonize or promote its activity in response to the cellular nutrient environment. Structural, biochemical, and biophysical studies of the GATOR1 complex and its interactors have advanced our understanding of how it regulates cellular metabolism when amino acids are limited. Here, we review the current research with a focus on GATOR1 structure, its enzymatic mechanism, and the growing group of proteins that regulate its activity. Finally, we discuss the implication of GATOR1 dysregulation in physiology and human diseases.
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Affiliation(s)
- Ilina Ivanova
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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9
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Bjorkman SH, Marti A, Jena J, Garcia Pena LM, Weatherford ET, Kato K, Koneru J, Chen J, Sood A, Potthoff MJ, Adams CM, Abel ED, Pereira RO. ATF4 Expression in Thermogenic Adipocytes is Required for Cold-Induced Thermogenesis in Mice via FGF21-Independent Mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.09.531964. [PMID: 36945390 PMCID: PMC10028960 DOI: 10.1101/2023.03.09.531964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In brown adipose tissue (BAT), short-term cold exposure induces the activating transcription factor 4 (ATF4), and its downstream target fibroblast growth factor 21 (FGF21). Induction of ATF4 in BAT in response to mitochondrial stress is required for thermoregulation, partially via upregulation of FGF21. In the present study, we tested the hypothesis that Atf4 and Fgf21 induction in BAT are both required for BAT thermogenesis by generating mice selectively lacking either Atf4 ( ATF4 BKO ) or Fgf21 (FGF21 BKO) in UCP1-expressing adipocytes. After 3 days of cold exposure, core body temperature was significantly reduced in ad-libitum -fed ATF4 BKO mice, which correlated with Fgf21 downregulation in brown and beige adipocytes, and impaired browning of white adipose tissue (WAT). Conversely, despite having reduced browning, FGF21 BKO mice had preserved core body temperature after cold exposure. Mechanistically, ATF4, but not FGF21, regulates amino acid import and metabolism in response to cold, likely contributing to BAT thermogenic capacity under ad libitum -fed conditions. Importantly, under fasting conditions, both ATF4 and FGF21 were required for thermogenesis in cold-exposed mice. Thus, ATF4 regulates BAT thermogenesis by activating amino acid metabolism in BAT in a FGF21-independent manner.
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10
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Kim JY, Kwon YG, Kim YM. The stress-responsive protein REDD1 and its pathophysiological functions. Exp Mol Med 2023; 55:1933-1944. [PMID: 37653030 PMCID: PMC10545776 DOI: 10.1038/s12276-023-01056-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/13/2023] [Accepted: 05/17/2023] [Indexed: 09/02/2023] Open
Abstract
Regulated in development and DNA damage-response 1 (REDD1) is a stress-induced protein that controls various cellular functions, including metabolism, oxidative stress, autophagy, and cell fate, and contributes to the pathogenesis of metabolic and inflammatory disorders, neurodegeneration, and cancer. REDD1 usually exerts deleterious effects, including tumorigenesis, metabolic inflammation, neurodegeneration, and muscle dystrophy; however, it also exhibits protective functions by regulating multiple intrinsic cell activities through either an mTORC1-dependent or -independent mechanism. REDD1 typically regulates mTORC1 signaling, NF-κB activation, and cellular pro-oxidant or antioxidant activity by interacting with 14-3-3 proteins, IκBα, and thioredoxin-interacting protein or 75 kDa glucose-regulated protein, respectively. The diverse functions of REDD1 depend on cell type, cellular context, interaction partners, and cellular localization (e.g., mitochondria, endomembrane, or cytosol). Therefore, comprehensively understanding the molecular mechanisms and biological roles of REDD1 under pathophysiological conditions is of utmost importance. In this review, based on the published literature, we highlight and discuss the molecular mechanisms underlying the REDD1 expression and its actions, biological functions, and pathophysiological roles.
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Affiliation(s)
- Ji-Yoon Kim
- Department of Anesthesiology and Pain Medicine, Hanyang University Hospital, Seoul, 04763, Republic of Korea
| | - Young-Guen Kwon
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Young-Myeong Kim
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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Shi F, Collins S. Regulation of mTOR Signaling: Emerging Role of Cyclic Nucleotide-Dependent Protein Kinases and Implications for Cardiometabolic Disease. Int J Mol Sci 2023; 24:11497. [PMID: 37511253 PMCID: PMC10380887 DOI: 10.3390/ijms241411497] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) kinase is a central regulator of cell growth and metabolism. It is the catalytic subunit of two distinct large protein complexes, mTOR complex 1 (mTORC1) and mTORC2. mTOR activity is subjected to tight regulation in response to external nutrition and growth factor stimulation. As an important mechanism of signaling transduction, the 'second messenger' cyclic nucleotides including cAMP and cGMP and their associated cyclic nucleotide-dependent kinases, including protein kinase A (PKA) and protein kinase G (PKG), play essential roles in mediating the intracellular action of a variety of hormones and neurotransmitters. They have also emerged as important regulators of mTOR signaling in various physiological and disease conditions. However, the mechanism by which cAMP and cGMP regulate mTOR activity is not completely understood. In this review, we will summarize the earlier work establishing the ability of cAMP to dampen mTORC1 activation in response to insulin and growth factors and then discuss our recent findings demonstrating the regulation of mTOR signaling by the PKA- and PKG-dependent signaling pathways. This signaling framework represents a new non-canonical regulation of mTOR activity that is independent of AKT and could be a novel mechanism underpinning the action of a variety of G protein-coupled receptors that are linked to the mTOR signaling network. We will further review the implications of these signaling events in the context of cardiometabolic disease, such as obesity, non-alcoholic fatty liver disease, and cardiac remodeling. The metabolic and cardiac phenotypes of mouse models with targeted deletion of Raptor and Rictor, the two essential components for mTORC1 and mTORC2, will be summarized and discussed.
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Affiliation(s)
- Fubiao Shi
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sheila Collins
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
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12
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Lotfollahzadeh S, Xia C, Amraei R, Hua N, Kandror KV, Farmer SR, Wei W, Costello CE, Chitalia V, Rahimi N. Inactivation of Minar2 in mice hyperactivates mTOR signaling and results in obesity. Mol Metab 2023; 73:101744. [PMID: 37245847 PMCID: PMC10267597 DOI: 10.1016/j.molmet.2023.101744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 05/30/2023] Open
Abstract
OBJECTIVE Obesity is a complex disorder and is linked to chronic diseases such as type 2 diabetes. Major intrinsically disordered NOTCH2-associated receptor2 (MINAR2) is an understudied protein with an unknown role in obesity and metabolism. The purpose of this study was to determine the impact of Minar2 on adipose tissues and obesity. METHOD We generated Minar2 knockout (KO) mice and used various molecular, proteomic, biochemical, histopathology, and cell culture studies to determine the pathophysiological role of Minar2 in adipocytes. RESULTS We demonstrated that the inactivation of Minar2 results in increased body fat with hypertrophic adipocytes. Minar2 KO mice on a high-fat diet develop obesity and impaired glucose tolerance and metabolism. Mechanistically, Minar2 interacts with Raptor, a specific and essential component of mammalian TOR complex 1 (mTORC1) and inhibits mTOR activation. mTOR is hyperactivated in the adipocytes deficient for Minar2 and over-expression of Minar2 in HEK-293 cells inhibited mTOR activation and phosphorylation of mTORC1 substrates, including S6 kinase, and 4E-BP1. CONCLUSION Our findings identified Minar2 as a novel physiological negative regulator of mTORC1 with a key role in obesity and metabolic disorders. Impaired expression or activation of MINAR2 could lead to obesity and obesity-associated diseases.
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Affiliation(s)
- Saran Lotfollahzadeh
- Renal Section, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Chaoshuang Xia
- Center for Biomedical Mass Spectrometry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Razie Amraei
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Ning Hua
- Biomed Research Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Konstantin V Kandror
- Department of Biochemistry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Stephen R Farmer
- Department of Biochemistry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Catherine E Costello
- Center for Biomedical Mass Spectrometry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA; Department of Biochemistry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
| | - Vipul Chitalia
- Renal Section, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA; Veterans Affairs Boston Healthcare System, Boston, MA, USA; Institute of Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Nader Rahimi
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
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13
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Montazeri M, Zarkesh M, Zadeh-Vakili A, Khalili D, Movahedi M, Khalaj A. Association of physical activity with increased PI3K and Akt mRNA levels in adipose tissues of obese and non-obese adults. Sci Rep 2023; 13:9291. [PMID: 37286617 DOI: 10.1038/s41598-023-36365-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 06/02/2023] [Indexed: 06/09/2023] Open
Abstract
Phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway regulates glucose and lipid metabolism. We examined the association of PI3K and Akt expression in visceral (VAT) and subcutaneous adipose tissue (SAT) with daily physical activity (PA) in non-diabetic obese and non-obese adults. In this cross-sectional study, we included 105 obese (BMI ≥ 30 kg/m2) and 71 non-obese (BMI < 30 kg/m2) subjects (aged/ ≥ 18 years). PA was measured using a valid and reliable International Physical Activity Questionnaire(IPAQ)-long-form, and the metabolic equivalent of task(MET) was calculated. Real-time PCR was performed to analyze the mRNA relative expression. VAT PI3K expression had a lower level in obese compared to non-obese (P = 0.015), while its expression was higher in active individuals than inactive ones (P = 0.029). SAT PI3K expression was increased in active individuals compared to inactive ones (P = 0.031). There was a rise in VAT Akt expression in the actives compared to the inactive participants (P = 0.037) and in non-obese/active compared to non-obese/inactive individuals (P = 0.026). Obese individuals had a decreased expression level of SAT Akt compared to non-obsesses (P = 0.005). VAT PI3K was directly and significantly associated with PA in obsesses (β = 1.457, P = 0.015). Positive association between PI3K and PA suggests beneficial effects of PA for obese individuals that can be partly described by PI3K/Akt pathway acceleration in adipose tissue.
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Affiliation(s)
- Marzieh Montazeri
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Zarkesh
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, PO Box: 19395-4763, Tehran, Iran.
| | - Azita Zadeh-Vakili
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, PO Box: 19395-4763, Tehran, Iran.
| | - Davood Khalili
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Monireh Movahedi
- Department of Biochemistry, Faculty of Biological Science, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Alireza Khalaj
- Tehran Obesity Treatment Center, Department of Surgery, Shahed University, Tehran, Iran
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14
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Vourdoumpa A, Paltoglou G, Charmandari E. The Genetic Basis of Childhood Obesity: A Systematic Review. Nutrients 2023; 15:1416. [PMID: 36986146 PMCID: PMC10058966 DOI: 10.3390/nu15061416] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/05/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Overweight and obesity in childhood and adolescence represents one of the most challenging public health problems of our century owing to its epidemic proportions and the associated significant morbidity, mortality, and increase in public health costs. The pathogenesis of polygenic obesity is multifactorial and is due to the interaction among genetic, epigenetic, and environmental factors. More than 1100 independent genetic loci associated with obesity traits have been currently identified, and there is great interest in the decoding of their biological functions and the gene-environment interaction. The present study aimed to systematically review the scientific evidence and to explore the relation of single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with changes in body mass index (BMI) and other measures of body composition in children and adolescents with obesity, as well as their response to lifestyle interventions. Twenty-seven studies were included in the qualitative synthesis, which consisted of 7928 overweight/obese children and adolescents at different stages of pubertal development who underwent multidisciplinary management. The effect of polymorphisms in 92 different genes was assessed and revealed SNPs in 24 genetic loci significantly associated with BMI and/or body composition change, which contribute to the complex metabolic imbalance of obesity, including the regulation of appetite and energy balance, the homeostasis of glucose, lipid, and adipose tissue, as well as their interactions. The decoding of the genetic and molecular/cellular pathophysiology of obesity and the gene-environment interactions, alongside with the individual genotype, will enable us to design targeted and personalized preventive and management interventions for obesity early in life.
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Affiliation(s)
- Aikaterini Vourdoumpa
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, National and Kapodistrian University of Athens Medical School, ‘Aghia Sophia’ Children’s Hospital, 11527 Athens, Greece
| | - George Paltoglou
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, National and Kapodistrian University of Athens Medical School, ‘Aghia Sophia’ Children’s Hospital, 11527 Athens, Greece
| | - Evangelia Charmandari
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, National and Kapodistrian University of Athens Medical School, ‘Aghia Sophia’ Children’s Hospital, 11527 Athens, Greece
- Division of Endocrinology and Metabolism, Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece
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15
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Liebscher G, Vujic N, Schreiber R, Heine M, Krebiehl C, Duta-Mare M, Lamberti G, de Smet CH, Hess MW, Eichmann TO, Hölzl S, Scheja L, Heeren J, Kratky D, Huber LA. The lysosomal LAMTOR / Ragulator complex is essential for nutrient homeostasis in brown adipose tissue. Mol Metab 2023; 71:101705. [PMID: 36907508 PMCID: PMC10074977 DOI: 10.1016/j.molmet.2023.101705] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023] Open
Abstract
OBJECTIVE In brown adipose tissue (iBAT), the balance between lipid/glucose uptake and lipolysis is tightly regulated by insulin signaling. Downstream of the insulin receptor, PDK1 and mTORC2 phosphorylate AKT, which activates glucose uptake and lysosomal mTORC1 signaling. The latter requires the late endosomal/lysosomal adaptor and MAPK and mTOR activator (LAMTOR/Ragulator) complex, which serves to translate the nutrient status of the cell to the respective kinase. However, the role of LAMTOR in metabolically active iBAT has been elusive. METHODS Using an AdipoqCRE-transgenic mouse line, we deleted LAMTOR2 (and thereby the entire LAMTOR complex) in adipose tissue (LT2 AKO). To examine the metabolic consequences, we performed metabolic and biochemical studies in iBAT isolated from mice housed at different temperatures (30 °C, room temperature and 5 °C), after insulin treatment, or in fasted and refed condition. For mechanistic studies, mouse embryonic fibroblasts (MEFs) lacking LAMTOR 2 were analyzed. RESULTS Deletion of the LAMTOR complex in mouse adipocytes resulted in insulin-independent AKT hyperphosphorylation in iBAT, causing increased glucose and fatty acid uptake, which led to massively enlarged lipid droplets. As LAMTOR2 was essential for the upregulation of de novo lipogenesis, LAMTOR2 deficiency triggered exogenous glucose storage as glycogen in iBAT. These effects are cell autonomous, since AKT hyperphosphorylation was abrogated by PI3K inhibition or by deletion of the mTORC2 component Rictor in LAMTOR2-deficient MEFs. CONCLUSIONS We identified a homeostatic circuit for the maintenance of iBAT metabolism that links the LAMTOR-mTORC1 pathway to PI3K-mTORC2-AKT signaling downstream of the insulin receptor.
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Affiliation(s)
- Gudrun Liebscher
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Nemanja Vujic
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Caroline Krebiehl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Madalina Duta-Mare
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Giorgia Lamberti
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Cedric H de Smet
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Michael W Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Sarah Hölzl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Dagmar Kratky
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
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16
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Madsen S, Nelson ME, Deshpande V, Humphrey SJ, Cooke KC, Howell A, Diaz-Vegas A, Burchfield JG, Stöckli J, James DE. Deep Proteome Profiling of White Adipose Tissue Reveals Marked Conservation and Distinct Features Between Different Anatomical Depots. Mol Cell Proteomics 2023; 22:100508. [PMID: 36787876 PMCID: PMC10014311 DOI: 10.1016/j.mcpro.2023.100508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 01/26/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
White adipose tissue is deposited mainly as subcutaneous adipose tissue (SAT), often associated with metabolic protection, and abdominal/visceral adipose tissue, which contributes to metabolic disease. To investigate the molecular underpinnings of these differences, we conducted comprehensive proteomics profiling of whole tissue and isolated adipocytes from these two depots across two diets from C57Bl/6J mice. The adipocyte proteomes from lean mice were highly conserved between depots, with the major depot-specific differences encoded by just 3% of the proteome. Adipocytes from SAT (SAdi) were enriched in pathways related to mitochondrial complex I and beiging, whereas visceral adipocytes (VAdi) were enriched in structural proteins and positive regulators of mTOR presumably to promote nutrient storage and cellular expansion. This indicates that SAdi are geared toward higher catabolic activity, while VAdi are more suited for lipid storage. By comparing adipocytes from mice fed chow or Western diet (WD), we define a core adaptive proteomics signature consisting of increased extracellular matrix proteins and decreased fatty acid metabolism and mitochondrial Coenzyme Q biosynthesis. Relative to SAdi, VAdi displayed greater changes with WD including a pronounced decrease in mitochondrial proteins concomitant with upregulation of apoptotic signaling and decreased mitophagy, indicating pervasive mitochondrial stress. Furthermore, WD caused a reduction in lipid handling and glucose uptake pathways particularly in VAdi, consistent with adipocyte de-differentiation. By overlaying the proteomics changes with diet in whole adipose tissue and isolated adipocytes, we uncovered concordance between adipocytes and tissue only in the visceral adipose tissue, indicating a unique tissue-specific adaptation to sustained WD in SAT. Finally, an in-depth comparison of isolated adipocytes and 3T3-L1 proteomes revealed a high degree of overlap, supporting the utility of the 3T3-L1 adipocyte model. These deep proteomes provide an invaluable resource highlighting differences between white adipose depots that may fine-tune their unique functions and adaptation to an obesogenic environment.
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Affiliation(s)
- Søren Madsen
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Marin E Nelson
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Vinita Deshpande
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Sean J Humphrey
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Kristen C Cooke
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Anna Howell
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Alexis Diaz-Vegas
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - James G Burchfield
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Jacqueline Stöckli
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - David E James
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia; Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia; Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia.
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17
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Lee E, Korf H, Vidal-Puig A. An adipocentric perspective on the development and progression of non-alcoholic fatty liver disease. J Hepatol 2023; 78:1048-1062. [PMID: 36740049 DOI: 10.1016/j.jhep.2023.01.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/20/2022] [Accepted: 01/19/2023] [Indexed: 02/07/2023]
Abstract
Alongside the liver, white adipose tissue (WAT) is critical in regulating systemic energy homeostasis. Although each organ has its specialised functions, they must work coordinately to regulate whole-body metabolism. Adipose tissues and the liver are relatively resilient and can adapt to an energy surplus by facilitating triglyceride (TG) storage up to a certain threshold level without significant metabolic disturbances. However, lipid storage in WAT beyond a "personalised" adiposity threshold becomes dysfunctional, leading to metabolic inflexibility, progressive inflammation, and aberrant adipokine secretion. Moreover, the failure of adipose tissue to store and mobilise lipids results in systemic knock-on lipid overload, particularly in the liver. Factors contributing to hepatic lipid overload include lipids released from WAT, dietary fat intake, and enhanced de novo lipogenesis. In contrast, extrahepatic mechanisms counteracting toxic hepatic lipid overload entail coordinated compensation through oxidation of surplus fatty acids in brown adipose tissue and storage of fatty acids as TGs in WAT. Failure of these integrated homeostatic mechanisms leads to quantitative increases and qualitative alterations to the lipidome of the liver. Initially, hepatocytes preferentially accumulate TG species leading to a relatively "benign" non-alcoholic fatty liver. However, with time, inflammatory responses ensue, progressing into more severe conditions such as non-alcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma, in some individuals (often without an early prognostic clue). Herein, we highlight the pathogenic importance of obesity-induced "adipose tissue failure", resulting in decreased adipose tissue functionality (i.e. fat storage capacity and metabolic flexibility), in the development and progression of NAFL/NASH.
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Affiliation(s)
- Eunyoung Lee
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK; Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba, Japan
| | - Hannelie Korf
- Laboratory of Hepatology, CHROMETA Department, KU Leuven, Leuven, Belgium.
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK; Centro de Innvestigacion Principe Felipe, Valencia, Spain; Cambridge University Nanjing Centre of Technology and Innovation, Nanjing, China.
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18
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Colas C, Mouchiroud M, Al Dow M, Kolnohuz A, Gélinas Y, Caron A, Laplante M. DEPTOR loss impairs brown adipocyte development in vitro but has limited impacts in mice. Mol Metab 2022; 67:101660. [PMID: 36535626 PMCID: PMC9827061 DOI: 10.1016/j.molmet.2022.101660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth and metabolism. In mice, activation of mTOR controls cold adaptation by promoting the recruitment and the activation of brown adipose tissue (BAT). DEP-domain containing mTOR-interacting protein (DEPTOR) interacts with mTOR to modulate its activity. Whether DEPTOR levels are modulated by cold in BAT and whether this protein regulates brown adipocyte development and thermogenic activation has never been tested. METHODS DEPTOR levels were measured in mouse tissues upon cold exposure and in brown preadipocytes following the induction of adipogenesis. Lentiviruses expressing short-hairpin RNA were used to repress DEPTOR expression in brown preadipocytes in vitro. Conditional deletion of DEPTOR in brown preadipocytes and in mature brown fat cells was achieved by crossing DEPTOR floxed mice with either Myf5-Cre or Ucp1-CreERT2 mice. These animals were exposed to cold and extensively phenotyped. RESULTS DEPTOR is highly expressed in BAT and its levels are induced by chronic cold exposure, a condition that triggers BAT expansion and activation. Supporting a role for DEPTOR in brown fat cell recruitment, we found that DEPTOR is induced during brown adipocyte development and that its depletion impairs adipogenesis in vitro. This adipogenic lesion was associated with defects in both Akt activation and the expression of key adipogenic regulators. Conditional deletion of DEPTOR in brown preadipocytes or mature brown fat cells did not impact BAT recruitment and thermogenesis in mice but slightly reduced the expression of adipogenic and lipogenic genes. CONCLUSIONS DEPTOR is highly expressed in BAT and its levels are dynamically regulated during brown fat cell development and upon cold exposure. Although DEPTOR depletion severely represses brown fat adipogenesis in vitro, its deletion is dispensable for BAT development, recruitment, and thermogenic activation in mice.
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Affiliation(s)
- Charles Colas
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Mathilde Mouchiroud
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Manal Al Dow
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Alona Kolnohuz
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Yves Gélinas
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Alexandre Caron
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Faculté de Pharmacie, Université Laval, 1050 avenue de la Médecine, Québec, QC, Canada, G1V0A6
| | - Mathieu Laplante
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3; Département de Médecine, Université Laval, 1050 avenue de la Médecine, Québec, QC, Canada, G1V0A6.
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19
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Li Q, Spalding KL. The regulation of adipocyte growth in white adipose tissue. Front Cell Dev Biol 2022; 10:1003219. [PMID: 36483678 PMCID: PMC9723158 DOI: 10.3389/fcell.2022.1003219] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/03/2022] [Indexed: 10/25/2023] Open
Abstract
Adipocytes can increase in volume up to a thousand-fold, storing excess calories as triacylglycerol in large lipid droplets. The dramatic morphological changes required of adipocytes demands extensive cytoskeletal remodeling, including lipid droplet and plasma membrane expansion. Cell growth-related signalling pathways are activated, stimulating the production of sufficient amino acids, functional lipids and nucleotides to meet the increasing cellular needs of lipid storage, metabolic activity and adipokine secretion. Continued expansion gives rise to enlarged (hypertrophic) adipocytes. This can result in a failure to maintain growth-related homeostasis and an inability to cope with excess nutrition or respond to stimuli efficiently, ultimately leading to metabolic dysfunction. We summarize recent studies which investigate the functional and cellular structure remodeling of hypertrophic adipocytes. How adipocytes adapt to an enlarged cell size and how this relates to cellular dysfunction are discussed. Understanding the healthy and pathological processes involved in adipocyte hypertrophy may shed light on new strategies for promoting healthy adipose tissue expansion.
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Affiliation(s)
- Qian Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Kirsty L. Spalding
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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20
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Bodur C, Kazyken D, Huang K, Tooley AS, Cho KW, Barnes TM, Lumeng CN, Myers MG, Fingar DC. TBK1-mTOR Signaling Attenuates Obesity-Linked Hyperglycemia and Insulin Resistance. Diabetes 2022; 71:2297-2312. [PMID: 35983955 PMCID: PMC9630091 DOI: 10.2337/db22-0256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022]
Abstract
The innate immune kinase TBK1 (TANK-binding kinase 1) responds to microbial-derived signals to initiate responses against viral and bacterial pathogens. More recent work implicates TBK1 in metabolism and tumorigenesis. The kinase mTOR (mechanistic target of rapamycin) integrates diverse environmental cues to control fundamental cellular processes. Our prior work demonstrated in cells that TBK1 phosphorylates mTOR (on S2159) to increase mTORC1 and mTORC2 catalytic activity and signaling. Here we investigate a role for TBK1-mTOR signaling in control of glucose metabolism in vivo. We find that mice with diet-induced obesity (DIO) but not lean mice bearing a whole-body "TBK1-resistant" Mtor S2159A knock-in allele (MtorA/A) display exacerbated hyperglycemia and systemic insulin resistance with no change in energy balance. Mechanistically, Mtor S2159A knock-in in DIO mice reduces mTORC1 and mTORC2 signaling in response to insulin and innate immune agonists, reduces anti-inflammatory gene expression in adipose tissue, and blunts anti-inflammatory macrophage M2 polarization, phenotypes shared by mice with tissue-specific inactivation of TBK1 or mTOR complexes. Tissues from DIO mice display elevated TBK1 activity and mTOR S2159 phosphorylation relative to lean mice. We propose a model whereby obesity-associated signals increase TBK1 activity and mTOR phosphorylation, which boost mTORC1 and mTORC2 signaling in parallel to the insulin pathway, thereby attenuating insulin resistance to improve glycemic control during diet-induced obesity.
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Affiliation(s)
- Cagri Bodur
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Dubek Kazyken
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Kezhen Huang
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Aaron Seth Tooley
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Kae Won Cho
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI
| | - Tammy M. Barnes
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Carey N. Lumeng
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI
| | - Martin G. Myers
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Diane C. Fingar
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
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21
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Abudujilile D, Wang W, Aimaier A, Chang L, Dong Y, Wang Y, Fan X, Ma Y, Wang Y, Ziyayiding D, Ma Y, Lv J, Li J. Cistanche tubulosa phenylethanoid glycosides suppressed adipogenesis in 3T3-L1 adipocytes and improved obesity and insulin resistance in high-fat diet induced obese mice. BMC Complement Med Ther 2022; 22:270. [PMID: 36229811 PMCID: PMC9564091 DOI: 10.1186/s12906-022-03743-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 09/23/2022] [Indexed: 11/10/2022] Open
Abstract
Background Cistanche tubulosa is an editable and medicinal traditional Chinese herb and phenylethanoid glycosides are its major components, which have shown various beneficial effects such as anti-tumor, anti-oxidant and neuroprotective activities. However, the anti-obesity effect of C. tubulosa phenylethanoid glycosides (CTPG) and their regulatory effect on gut microbiota are still unclear. In the present study, we investigated its anti-obesity effect and regulatory effect on gut microbiota by 3T3-L1 cell model and obesity mouse model. Methods 3T3-L1 adipocytes were used to evaluate CTPG effects on adipogenesis and lipids accumulation. Insulin resistant 3T3-L1 cells were induced and used to measure CTPG effects on glucose consumption and insulin sensitivity. High-fat diet (HFD)-induced C57BL/6 obese mice were used to investigate CTPG effects on fat deposition, glucose and lipid metabolism, insulin resistance and intestinal microorganism. Results In vitro data showed that CTPG significantly decreased the triglyceride (TG) and non-esterified fatty acid (NEFA) contents of the differentiated 3T3-L1 adipocytes in a concentration-dependent manner without cytotoxicity, and high concentration (100 µg/ml) of CTPG treatment dramatically suppressed the level of monocyte chemoattractant protein-1 (MCP-1) in 3T3-L1 mature adipocytes. Meanwhile, CTPG increased glucose consumption and decreased NEFA level in insulin resistant 3T3-L1 cells. We further found that CTPG protected mice from the development of obesity by inhibiting the expansion of adipose tissue and adipocyte hypertrophy, and improved hepatic steatosis by activating AMPKα to reduce hepatic fat accumulation. CTPG ameliorated HFD-induced hyperinsulinemia, hyperglycemia, inflammation and insulin resistance by activating IRS1/Akt/GLUT4 insulin signaling pathway in white adipose tissue. Moreover, gut microbiota structure and metabolic functions in HFD-induced obese mice was changed by CTPG, especially short chain fatty acids-producing bacteria including Blautia, Roseburia, Butyrivibrio and Bacteriodes were significantly increased by CTPG treatment. Conclusions CTPG effectively suppressed adipogenesis and lipid accumulation in 3T3-L1 adipocytes and ameliorated HFD-induced obesity and insulin resistance through activating AMPKα and IRS1/AKT/GLUT4 signaling pathway and regulating the composition and metabolic functions of gut microbiota. Supplementary Information The online version contains supplementary material available at 10.1186/s12906-022-03743-6.
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Affiliation(s)
- Dilinazi Abudujilile
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Weilan Wang
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Alimu Aimaier
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Lili Chang
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Yuliang Dong
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Yiye Wang
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Xu Fan
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Yu Ma
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Yongli Wang
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Dilinigeer Ziyayiding
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Yuan Ma
- grid.413254.50000 0000 9544 7024College of Resource and Environment Sciences, Xinjiang University, Urumqi, 830017 China
| | - Jie Lv
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
| | - Jinyao Li
- grid.413254.50000 0000 9544 7024Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017 China
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22
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The role of protein kinases as key drivers of metabolic dysfunction-associated fatty liver disease progression: New insights and future directions. Life Sci 2022; 305:120732. [PMID: 35760093 DOI: 10.1016/j.lfs.2022.120732] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 06/08/2022] [Accepted: 06/21/2022] [Indexed: 02/07/2023]
Abstract
Metabolic dysfunction-associated fatty liver disease (MAFLD), proposed in 2020 is a novel term for non-alcoholic fatty liver disease (NAFLD) which was coined for the first time in 1980. It is a leading cause of the most chronic liver disease and hepatic failure all over the world, and unfortunately, with no licensed drugs for treatment yet. The progress of the disease is driven by the triggered inflammatory process, oxidative stress, and insulin resistance in many pathways, starting with simple hepatic steatosis to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and liver cancer. Protein kinases (PKs), such as MAPK, ErbB, PKC, PI3K/Akt, and mTOR, govern most of the pathological pathways by acting on various downstream key points in MAFLD and regulating both hepatic gluco- lipo-neogenesis and inflammation. Therefore, modulating the function of those potential protein kinases that are effectively involved in MAFLD might be a promising therapeutic approach for tackling this disease. In the current review, we have discussed the key role of protein kinases in the pathogenesis of MAFLD and performed a protein-protein interaction (PPI) network among the main proteins of each kinase pathway with MAFLD-related proteins to predict the most likely targets of the PKs in MAFLD. Moreover, we have reported the experimental, pre-clinical, and clinical data for the most recent investigated molecules that are activating p38-MAPK and AMPK proteins and inhibiting the other PKs to improve MAFLD condition by regulating oxidation and inflammation signalling.
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23
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Simcox J, Lamming DW. The central moTOR of metabolism. Dev Cell 2022; 57:691-706. [PMID: 35316619 PMCID: PMC9004513 DOI: 10.1016/j.devcel.2022.02.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) functions as a central regulator of metabolism, integrating diverse nutritional and hormonal cues to control anabolic processes, organismal physiology, and even aging. This review discusses the current state of knowledge regarding the regulation of mTOR signaling and the metabolic regulation of the four macromolecular building blocks of the cell: carbohydrate, nucleic acid, lipid, and protein by mTOR. We review the role of mTOR in the control of organismal physiology and aging through its action in key tissues and discuss the potential for clinical translation of mTOR inhibition for the treatment and prevention of diseases of aging.
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Affiliation(s)
- Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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24
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Chen Y, Fernandez EA, Roger C, Lopez-Mejia IC, Fajas Coll L, Ji H. Adipocyte-Specific CDK7 Ablation Leads to Progressive Loss of Adipose Tissue and Metabolic Dysfunction. FEBS Lett 2022; 596:1434-1444. [PMID: 35294049 DOI: 10.1002/1873-3468.14335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 11/12/2022]
Abstract
Adipose tissue regulates whole-body energy homeostasis. Both lipodystrophy and obesity, the extreme and opposite aspects of adipose tissue dysfunction, result in metabolic disorders: insulin resistance and hepatic steatosis. Cyclin-dependent kinases (CDKs) have been reported to be involved in adipose tissue development and functions. Using adipose tissue-specific knockout mice, here we demonstrate that the deletion of CDK7 in adipose tissue results in progressive lipodystrophy, insulin resistance, impaired adipokine secretion and down-regulation of fat-specific genes, which are aggravated on high-fat diet and during aging. Our studies suggest that CDK7 is a key regulatory component of adipose tissue maintenance and systemic energy homeostasis.
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Affiliation(s)
- Yizhe Chen
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Eric Aria Fernandez
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Catherine Roger
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | | | - Lluis Fajas Coll
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,Institut National de la Santé et de la Recherche Médicale (Inserm), Languedoc Roussillon, France
| | - Honglei Ji
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
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25
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Integrating adipocyte insulin signaling and metabolism in the multi-omics era. Trends Biochem Sci 2022; 47:531-546. [PMID: 35304047 DOI: 10.1016/j.tibs.2022.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/08/2022] [Accepted: 02/21/2022] [Indexed: 12/16/2022]
Abstract
Insulin stimulates glucose uptake into adipocytes via mTORC2/AKT signaling and GLUT4 translocation and directs glucose carbons into glycolysis, glycerol for TAG synthesis, and de novo lipogenesis. Adipocyte insulin resistance is an early indicator of type 2 diabetes in obesity, a worldwide health crisis. Thus, understanding the interplay between insulin signaling and central carbon metabolism pathways that maintains adipocyte function, blood glucose levels, and metabolic homeostasis is critical. While classically viewed through the lens of individual enzyme-substrate interactions, advances in mass spectrometry are beginning to illuminate adipocyte signaling and metabolic networks on an unprecedented scale, yet this is just the tip of the iceberg. Here, we review how 'omics approaches help to elucidate adipocyte insulin action in cellular time and space.
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26
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Dattilo A, Ceccarini G, Scabia G, Magno S, Quintino L, Pelosini C, Salvetti G, Cusano R, Massidda M, Montanelli L, Gilio D, Gatti G, Giacomina A, Costa M, Santini F, Maffei M. Circulating Levels of MiRNAs From 320 Family in Subjects With Lipodystrophy: Disclosing Novel Signatures of the Disease. Front Endocrinol (Lausanne) 2022; 13:866679. [PMID: 35733784 PMCID: PMC9207177 DOI: 10.3389/fendo.2022.866679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Lipodystrophy (LD) indicates a group of rare disorders, with generalized or partial loss of white adipose tissue (WAT) often associated with metabolic derangements. Heterogeneity/wide spectrum of the disease and lack of biomarkers make diagnosis often difficult. MicroRNAs are important to maintain a correct WAT function and WAT is a source of circulating miRNAs (cmiRs). miRNAs from 320 family were previously detected in the WAT and variably associated to the metabolic syndrome. Our aim was then to investigate if LD can result in altered abundance of cmiRs-320. We collected samples from a cohort of LD subjects of various subtypes and from age matched controls. Use of quantitative PCR determined that cmiRs- 320a-3p, 320b, 320c, 320e are upregulated, while 320d is downregulated in LD. CmiRs-320 power as classifiers was more powerful in the most extreme and defined forms of LD, including the generalized and the Dunnigan subtypes. cmiR-320a-3p showed significant inverse relationships with plasma leptin (P < 0.0001), typically low in LD. The hepatic enzymes gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the marker of inflammation C-reactive protein (CRP) were inversely related to cmiR 320d (P < 0.05, for CRP and GGT; P < 0.01, for AST and ALT). Gene ontology analysis revealed cell-cell adhesion as a process regulated by 320 miRNAs targets, thus disclosing a novel route to investigate origin of WAT loss/dysfunction. In conclusion, cmiRs-320 constitute novel biomarkers of LD, abundance of miR320a-3p is inversely associated to indicators related to WAT function, while downregulation of cmiR-320d predicts an altered hepatic profile and higher inflammation.
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Affiliation(s)
- Alessia Dattilo
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Giovanni Ceccarini
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Gaia Scabia
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
- National Research Council, Institute of Clinical Physiology, Pisa, Italy
| | - Silvia Magno
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Lara Quintino
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Caterina Pelosini
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Guido Salvetti
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Roberto Cusano
- Center for Advanced Studies, Research and Development in Sardinia, Pula (CA), Italy
| | - Matteo Massidda
- Center for Advanced Studies, Research and Development in Sardinia, Pula (CA), Italy
| | - Lucia Montanelli
- Department of Clinical and Experimental Medicine, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Donatella Gilio
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Gianluca Gatti
- Plastic and Reconstructive Surgery Unit, Hospital of Pisa, Pisa, Italy
| | | | - Mario Costa
- National Research Council, Institute of Neuroscience, Pisa, Italy
- Centro Pisano Flash Radiotherapy, Center for Instrument Sharing of the University of Pisa (CPFR@CISUP), Pisa University Hospital, Pisa, Italy
| | - Ferruccio Santini
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
| | - Margherita Maffei
- Obesity and Lipodystrophy Center, Endocrinology Unit, Pisa University Hospital, Pisa, Italy
- National Research Council, Institute of Clinical Physiology, Pisa, Italy
- *Correspondence: Margherita Maffei,
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27
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Feng R, Chen L, Chen K. Cytotoxicity and changes in gene expression under aluminium potassium sulfate on Spodoptera frugiperda 9 cells. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:2056-2070. [PMID: 34546441 DOI: 10.1007/s10646-021-02478-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Aluminium, a substance found in large amounts in nature, has been widely used for various purposes, especially food additives. The effects of long-term and excessive exposure to aluminium on human health are receiving increasing attention. The extensive human use of aluminium food additives can also cause aluminium to enter the ecosystem, where it has significant impacts on insects. This study explored the cytotoxicity and changes in gene expression under aluminium potassium sulfate toward Spodoptera frugiperda 9 cells. We found that high concentrations of aluminium resulted in cell enlargement and cell membrane breakage, decreased cell vitality, and apoptosis. Through RNA-Seq transcriptomics, we found that aluminium ions may inhibit the expression of regulatory-associated protein of mTOR, tdIns-dependent protein kinase-1, and small heat shock proteins (heat shock 70 kDa protein and crystallin alpha B), leading to changes in mTOR-related pathways (such as the longevity regulation pathway and PI3K-Akt signalling pathway), and promoting cell apoptosis. On the other hand, aluminium ions lead to the overexpression of GSH S-transferase, prostaglandin-H2 D-isomerase and pyrimidodiazepine synthase, and induce intracellular oxidative damage, which ultimately affects cell growth and apoptosis through a series of cascade reactions.
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Affiliation(s)
- Rong Feng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu province, China
| | - Liang Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu province, China
| | - Keping Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu province, China.
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu province, China.
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28
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Lu Q, Hou Q, Cao K, Sun X, Liang Y, Gu M, Xue X, Zhao AZ, Dai C. Complement factor B in high glucose-induced podocyte injury and diabetic kidney disease. JCI Insight 2021; 6:147716. [PMID: 34622800 PMCID: PMC8525650 DOI: 10.1172/jci.insight.147716] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 08/27/2021] [Indexed: 02/06/2023] Open
Abstract
The role and mechanisms for upregulating complement factor B (CFB) expression in podocyte dysfunction in diabetic kidney disease (DKD) are not fully understood. Here, analyzing Gene Expression Omnibus GSE30528 data, we identified genes enriched in mTORC1 signaling, CFB, and complement alternative pathways in podocytes from patients with DKD. In mouse models, podocyte mTOR complex 1 (mTORC1) signaling activation was induced, while blockade of mTORC1 signaling reduced CFB upregulation, alternative complement pathway activation, and podocyte injury in the glomeruli. Knocking down CFB remarkably alleviated alternative complement pathway activation and DKD in diabetic mice. In cultured podocytes, high glucose treatment activated mTORC1 signaling, stimulated STAT1 phosphorylation, and upregulated CFB expression, while blockade of mTORC1 or STAT1 signaling abolished high glucose–upregulated CFB expression. Additionally, high glucose levels downregulated protein phosphatase 2Acα (PP2Acα) expression, while PP2Acα deficiency enhanced high glucose–induced mTORC1/STAT1 activation, CFB induction, and podocyte injury. Taken together, these findings uncover a mechanism by which CFB mediates podocyte injury in DKD.
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Affiliation(s)
| | | | - Kai Cao
- Center for Kidney Disease and
| | - Xiaoli Sun
- Department of Clinical Genetics, Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | | | | | - Xian Xue
- Department of Clinical Genetics, Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Allan Zijian Zhao
- Institute of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, China
| | - Chunsun Dai
- Center for Kidney Disease and.,Department of Clinical Genetics, Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
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29
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Yang G, Francis D, Krycer JR, Larance M, Zhang Z, Novotny CJ, Diaz-Vegas A, Shokat KM, James DE. Dissecting the biology of mTORC1 beyond rapamycin. Sci Signal 2021; 14:eabe0161. [PMID: 34546793 DOI: 10.1126/scisignal.abe0161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Guang Yang
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Deanne Francis
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - James R Krycer
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Mark Larance
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Ziyang Zhang
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - Chris J Novotny
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - Alexis Diaz-Vegas
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Kevan M Shokat
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - David E James
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia.,University of Sydney, Sydney Medical School, Sydney, New South Wales 2006, Australia
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30
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Autophagy-Associated IL-15 Production Is Involved in the Pathogenesis of Leprosy Type 1 Reaction. Cells 2021; 10:cells10092215. [PMID: 34571865 PMCID: PMC8468917 DOI: 10.3390/cells10092215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 01/18/2023] Open
Abstract
Leprosy reactional episodes are acute inflammatory events that may occur during the clinical course of the disease. Type 1 reaction (T1R) is associated with an increase in neural damage, and the understanding of the molecular pathways related to T1R onset is pivotal for the development of strategies that may effectively control the reaction. Interferon-gamma (IFN-γ) is a key cytokine associated with T1R onset and is also associated with autophagy induction. Here, we evaluated the modulation of the autophagy pathway in Mycobacterium leprae-stimulated cells in the presence or absence of IFN-γ. We observed that IFN-γ treatment promoted autophagy activation and increased the expression of genes related to the formation of phagosomes, autophagy regulation and function, or lysosomal pathways in M. leprae-stimulated cells. IFN-γ increased interleukin (IL)-15 secretion in M. leprae-stimulated THP-1 cells in a process associated with autophagy activation. We also observed higher IL15 gene expression in multibacillary (MB) patients who later developed T1R during clinical follow-up when compared to MB patients who did not develop the episode. By overlapping gene expression patterns, we observed 13 common elements shared between T1R skin lesion cells and THP-1 cells stimulated with both M. leprae and IFN-γ. Among these genes, the autophagy regulator Translocated Promoter Region, Nuclear Basket Protein (TPR) was significantly increased in T1R cells when compared with non-reactional MB cells. Overall, our results indicate that IFN-γ may induce a TPR-mediated autophagy transcriptional program in M. leprae-stimulated cells similar to that observed in skin cells during T1R by a pathway that involves IL-15 production, suggesting the involvement of this cytokine in the pathogenesis of T1R.
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Andrade ML, Gilio GR, Perandini LA, Peixoto AS, Moreno MF, Castro É, Oliveira TE, Vieira TS, Ortiz-Silva M, Thomazelli CA, Chaves-Filho AB, Belchior T, Chimin P, Magdalon J, Ivison R, Pant D, Tsai L, Yoshinaga MY, Miyamoto S, Festuccia WT. PPARγ-induced upregulation of subcutaneous fat adiponectin secretion, glyceroneogenesis and BCAA oxidation requires mTORC1 activity. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158967. [PMID: 34004356 PMCID: PMC9391032 DOI: 10.1016/j.bbalip.2021.158967] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/27/2021] [Accepted: 05/08/2021] [Indexed: 12/13/2022]
Abstract
The nutrient sensors peroxisome proliferator-activated receptor γ (PPARγ) and mechanistic target of rapamycin complex 1 (mTORC1) closely interact in the regulation of adipocyte lipid storage. The precise mechanisms underlying this interaction and whether this extends to other metabolic processes and the endocrine function of adipocytes are still unknown. We investigated herein the involvement of mTORC1 as a mediator of the actions of the PPARγ ligand rosiglitazone in subcutaneous inguinal white adipose tissue (iWAT) mass, endocrine function, lipidome, transcriptome and branched-chain amino acid (BCAA) metabolism. Mice bearing regulatory associated protein of mTOR (Raptor) deletion and therefore mTORC1 deficiency exclusively in adipocytes and littermate controls were fed a high-fat diet supplemented or not with the PPARγ agonist rosiglitazone (30 mg/kg/day) for 8 weeks and evaluated for iWAT mass, lipidome, transcriptome (Rnaseq), respiration and BCAA metabolism. Adipocyte mTORC1 deficiency not only impaired iWAT adiponectin transcription, synthesis and secretion, PEPCK mRNA levels, triacylglycerol synthesis and BCAA oxidation and mRNA levels of related proteins but also completely blocked the upregulation in these processes induced by pharmacological PPARγ activation with rosiglitazone. Mechanistically, adipocyte mTORC1 deficiency impairs PPARγ transcriptional activity by reducing PPARγ protein content, as well as by downregulating C/EBPα, a co-partner and facilitator of PPARγ. In conclusion, mTORC1 and PPARγ are essential partners involved in the regulation of subcutaneous adipose tissue adiponectin production and secretion and BCAA oxidative metabolism.
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Affiliation(s)
- Maynara L Andrade
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Gustavo R Gilio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luiz A Perandini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Albert S Peixoto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mayara F Moreno
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Érique Castro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Tiago E Oliveira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Thayna S Vieira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Milene Ortiz-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Caroline A Thomazelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Adriano B Chaves-Filho
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil; Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconness Medical Center, Boston, MA, USA
| | - Thiago Belchior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Patricia Chimin
- Department of Physical Education, Physical Education and Sports Center, Londrina State University, Londrina, Brazil
| | | | | | - Deepti Pant
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconness Medical Center, Boston, MA, USA
| | - Linus Tsai
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconness Medical Center, Boston, MA, USA
| | - Marcos Y Yoshinaga
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Brazil
| | - Sayuri Miyamoto
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Brazil
| | - William T Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Tooley AS, Kazyken D, Bodur C, Gonzalez IE, Fingar DC. The innate immune kinase TBK1 directly increases mTORC2 activity and downstream signaling to Akt. J Biol Chem 2021; 297:100942. [PMID: 34245780 PMCID: PMC8342794 DOI: 10.1016/j.jbc.2021.100942] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/21/2021] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
TBK1 responds to microbes to initiate cellular responses critical for host innate immune defense. We found previously that TBK1 phosphorylates mTOR (mechanistic target of rapamycin) on S2159 to increase mTOR complex 1 (mTORC1) signaling in response to the growth factor EGF and the viral dsRNA mimetic poly(I:C). mTORC1 and the less well studied mTORC2 respond to diverse cues to control cellular metabolism, proliferation, and survival. Although TBK1 has been linked to Akt phosphorylation, a direct relationship between TBK1 and mTORC2, an Akt kinase, has not been described. By studying MEFs lacking TBK1, as well as MEFs, macrophages, and mice bearing an Mtor S2159A knock-in allele (MtorA/A) using in vitro kinase assays and cell-based approaches, we demonstrate here that TBK1 activates mTOR complex 2 (mTORC2) directly to increase Akt phosphorylation. We find that TBK1 and mTOR S2159 phosphorylation promotes mTOR-dependent phosphorylation of Akt in response to several growth factors and poly(I:C). Mechanistically, TBK1 coimmunoprecipitates with mTORC2 and phosphorylates mTOR S2159 within mTORC2 in cells. Kinase assays demonstrate that TBK1 and mTOR S2159 phosphorylation increase mTORC2 intrinsic catalytic activity. Growth factors failed to activate TBK1 or increase mTOR S2159 phosphorylation in MEFs. Thus, basal TBK1 activity cooperates with growth factors in parallel to increase mTORC2 (and mTORC1) signaling. Collectively, these results reveal cross talk between TBK1 and mTOR, key regulatory nodes within two major signaling networks. As TBK1 and mTOR contribute to tumorigenesis and metabolic disorders, these kinases may work together in a direct manner in a variety of physiological and pathological settings.
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Affiliation(s)
- Aaron Seth Tooley
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Dubek Kazyken
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Cagri Bodur
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ian E Gonzalez
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Diane C Fingar
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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Zhang Z, Yang D, Xiang J, Zhou J, Cao H, Che Q, Bai Y, Guo J, Su Z. Non-shivering Thermogenesis Signalling Regulation and Potential Therapeutic Applications of Brown Adipose Tissue. Int J Biol Sci 2021; 17:2853-2870. [PMID: 34345212 PMCID: PMC8326120 DOI: 10.7150/ijbs.60354] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/23/2021] [Indexed: 12/25/2022] Open
Abstract
In mammals, thermogenic organs exist in the body that increase heat production and enhance energy regulation. Because brown adipose tissue (BAT) consumes energy and generates heat, increasing energy expenditure via BAT might be a potential strategy for new treatments for obesity and obesity-related diseases. Thermogenic differentiation affects normal adipose tissue generation, emphasizing the critical role that common transcriptional regulation factors might play in common characteristics and sources. An understanding of thermogenic differentiation and related factors could help in developing ways to improve obesity indirectly or directly through targeting of specific signalling pathways. Many studies have shown that the active components of various natural products promote thermogenesis through various signalling pathways. This article reviews recent major advances in this field, including those in the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA), cyclic guanosine monophosphate-GMP-dependent protein kinase G (cGMP-AKT), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), transforming growth factor-β/bone morphogenic protein (TGF-β/BMP), transient receptor potential (TRP), Wnt, nuclear factor-κ-light-chain-enhancer of activated B cells (NF-κΒ), Notch and Hedgehog (Hh) signalling pathways in brown and brown-like adipose tissue. To provide effective information for future research on weight-loss nutraceuticals or drugs, this review also highlights the natural products and their active ingredients that have been reported in recent years to affect thermogenesis and thus contribute to weight loss via the above signalling pathways.
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Affiliation(s)
- Zhengyan Zhang
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou 510006, China.,Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Di Yang
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou 510006, China.,Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Junwei Xiang
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou 510006, China.,Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Jingwen Zhou
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou 510006, China.,Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Hua Cao
- Guangdong Cosmetics Engineering & Technology Research Center, School of Chemistry and Chemical Engneering, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Qishi Che
- Guangzhou Rainhome Pharm & Tech Co., Ltd., Guangzhou 510663, China
| | - Yan Bai
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou 510310, China
| | - Jiao Guo
- Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Zhengquan Su
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou 510006, China.,Guangdong Metabolic Diseases Research Centre of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
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Deleyto-Seldas N, Efeyan A. The mTOR-Autophagy Axis and the Control of Metabolism. Front Cell Dev Biol 2021; 9:655731. [PMID: 34277603 PMCID: PMC8281972 DOI: 10.3389/fcell.2021.655731] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/19/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR), master regulator of cellular metabolism, exists in two distinct complexes: mTOR complex 1 and mTOR complex 2 (mTORC1 and 2). MTORC1 is a master switch for most energetically onerous processes in the cell, driving cell growth and building cellular biomass in instances of nutrient sufficiency, and conversely, allowing autophagic recycling of cellular components upon nutrient limitation. The means by which the mTOR kinase blocks autophagy include direct inhibition of the early steps of the process, and the control of the lysosomal degradative capacity of the cell by inhibiting the transactivation of genes encoding structural, regulatory, and catalytic factors. Upon inhibition of mTOR, autophagic recycling of cellular components results in the reactivation of mTORC1; thus, autophagy lies both downstream and upstream of mTOR. The functional relationship between the mTOR pathway and autophagy involves complex regulatory loops that are significantly deciphered at the cellular level, but incompletely understood at the physiological level. Nevertheless, genetic evidence stemming from the use of engineered strains of mice has provided significant insight into the overlapping and complementary metabolic effects that physiological autophagy and the control of mTOR activity exert during fasting and nutrient overload.
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Affiliation(s)
- Nerea Deleyto-Seldas
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Alejo Efeyan
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Center (CNIO), Madrid, Spain
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Guo Z, Chen X, Feng P, Yu Q. Short-term rapamycin administration elevated testosterone levels and exacerbated reproductive disorder in dehydroepiandrosterone-induced polycystic ovary syndrome mice. J Ovarian Res 2021; 14:64. [PMID: 33947426 PMCID: PMC8097915 DOI: 10.1186/s13048-021-00813-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/16/2021] [Indexed: 11/15/2022] Open
Abstract
Background Polycystic ovary syndrome (PCOS) is a multifactorial endocrinopathy that affects reproduction and metabolism. Mammalian target of rapamycin (mTOR) has been shown to participate in female reproduction under physiological and pathological conditions. This study aimed to investigate the role of mTOR complex 1 (mTORC1) signaling in dehydroepiandrosterone (DHEA)-induced PCOS mice. Results Female C57BL/6J mice were randomly assigned into three groups: control group, DHEA group, and DHEA + rapamycin group. All DHEA-treated mice were administered 6 mg/100 g DHEA for 21 consecutive days, and the DHEA + rapamycin group was intraperitoneally injected with 4 mg/kg rapamycin every other day for the last 14 days of the DHEA treatment. There was no obvious change in the expression of mTORC1 signaling in the ovaries of the control and DHEA groups. Rapamycin did not protect against DHEA-induced acyclicity and PCO morphology, but impeded follicle development and elevated serum testosterone levels in DHEA-induced mice, which was related with suppressed Hsd3b1, Cyp17a1, and Cyp19a1 expression. Moreover, rapamycin also exacerbated insulin resistance but relieved lipid metabolic disturbance in the short term. Conclusions Rapamycin exacerbated reproductive imbalance in DHEA-induced PCOS mice, which characterized by elevated testosterone levels and suppressed steroid synthesis. This underscores the need for new mTORC1-specific and tissue-specific mTOR-related drugs for reproductive disorders.
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Affiliation(s)
- Zaixin Guo
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaohan Chen
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Penghui Feng
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Qi Yu
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
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Zhu Y, Jing L, Li X, Zheng D, Zhou G, Zhang Y, Sang Y, Shi Z, Sun Z, Zhou X. Decabromodiphenyl ether disturbs hepatic glycolipid metabolism by regulating the PI3K/AKT/GLUT4 and mTOR/PPARγ/RXRα pathway in mice and L02 cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:142936. [PMID: 33138992 DOI: 10.1016/j.scitotenv.2020.142936] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/25/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
Decabromodiphenyl ether (BDE-209) is a persistent environmental pollutant that poses great risks to human health and has been associated with glucose and lipid metabolism. However, the mechanisms by which BDE-209 disturbs glycolipid metabolism in the liver remain unclear. Therefore, this study sought to confirm the effects of BDE-209 on glycolipid metabolism in mice livers and L02 cells to elucidate potential mechanisms of action. In vivo BDE-209 exposure caused histological damage and lipid accumulation, elevated glucose, low-density lipoprotein, total cholesterol, and triglyceride levels, and decreased glycogen and high-density lipoprotein levels in mice livers. Moreover, in vitro BDE-209 exposure not only induced L02 cells cytotoxicity (i.e., reduced cell viability and increased LDH leakage and ROS generation) but also increased glucose and triglyceride concentrations in L02 cells. Furthermore, IGF-1, an activator of the PI3K-AKT pathway, markedly inhibited BDE-209-induced glucose concentration increase in L02 cells and antagonized the inhibitory effect of BDE-209 on the PI3K/AKT/GLUT4 pathway by counteracting the changes in the expression levels of p-IRS, AKT, PI3K, p-AKT, and GLUT4. Moreover, GW9662, a PPARγ inhibitor, blocked lipid accumulation and the upregulation of the mTOR/PPARγ/RXRα pathway in L02 cells induced by BDE-209 by relieving the increases in p-mTOR, PPARγ, and RXRα protein expression levels. In summary, this study revealed that BDE-209 disrupted glycolipid metabolism by inhibiting the PI3K/AKT/GLUT4 pathway and activating the mTOR/PPARγ/RXRα pathway.
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Affiliation(s)
- Yupeng Zhu
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China; Haidian Maternal&Child Health Hospital, Health Care Department for Women, Beijing 100080, China
| | - Li Jing
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xiangyang Li
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Dan Zheng
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Guiqing Zhou
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Yue Zhang
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Yujian Sang
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Zhixiong Shi
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Zhiwei Sun
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xianqing Zhou
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
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Cox AR, Chernis N, Kim KH, Masschelin PM, Saha PK, Briley SM, Sharp R, Li X, Felix JB, Sun Z, Moore DD, Pangas SA, Hartig SM. Ube2i deletion in adipocytes causes lipoatrophy in mice. Mol Metab 2021; 48:101221. [PMID: 33771728 PMCID: PMC8080079 DOI: 10.1016/j.molmet.2021.101221] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/11/2021] [Accepted: 03/22/2021] [Indexed: 12/18/2022] Open
Abstract
Objective White adipose tissue (WAT) expansion regulates energy balance and overall metabolic homeostasis. The absence or loss of WAT occurring through lipodystrophy and lipoatrophy contributes to the development of hepatic steatosis and insulin resistance. We previously demonstrated that sole small ubiquitin-like modifier (SUMO) E2-conjugating enzyme Ube2i represses human adipocyte differentiation. The role of Ube2i during WAT development remains unknown. Methods To determine how Ube2i impacts body composition and energy balance, we generated adipocyte-specific Ube2i knockout mice (Ube2ia-KO). CRISPR/Cas9 gene editing inserted loxP sites flanking exons 3 and 4 at the Ube2i locus. Subsequent genetic crosses to Adipoq-Cre transgenic mice allowed deletion of Ube2i in white and brown adipocytes. We measured multiple metabolic endpoints that describe energy balance and carbohydrate metabolism in Ube2ia-KO and littermate controls during postnatal growth. Results Surprisingly, Ube2ia-KO mice developed hyperinsulinemia and hepatic steatosis. Global energy balance defects emerged from dysfunctional WAT marked by pronounced local inflammation, loss of serum adipokines, hepatomegaly, and near absence of major adipose tissue depots. We observed progressive lipoatrophy that commences in the early adolescent period. Conclusions Our results demonstrate that Ube2i expression in mature adipocytes allows WAT expansion during postnatal growth. Deletion of Ube2i in fat cells compromises and diminishes adipocyte function that induces WAT inflammation and ectopic lipid accumulation in the liver. Our findings reveal an indispensable role for Ube2i during white adipocyte expansion and endocrine control of energy balance. A new mouse model reveals that Ube2i loss in fat cells impacts body composition. Ube2i fat-specific knockout (Ube2ia-KO) causes fatty liver and hyperinsulinemia. Ube2ia-KO mice develop metabolic inflexibility and cold intolerance. Inflammation and caspase activation of cell death occur in Ube2ia-KO adipocytes.
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Affiliation(s)
- Aaron R Cox
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Natasha Chernis
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Kang Ho Kim
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Peter M Masschelin
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Pradip K Saha
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Shawn M Briley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Robert Sharp
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Xin Li
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Jessica B Felix
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Zheng Sun
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - David D Moore
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Stephanie A Pangas
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Sean M Hartig
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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Tangseefa P, Martin SK, Arthur A, Panagopoulos V, Page AJ, Wittert GA, Proud CG, Fitter S, Zannettino ACW. Deletion of Rptor in Preosteoblasts Reveals a Role for the Mammalian Target of Rapamycin Complex 1 (mTORC1) Complex in Dietary-Induced Changes to Bone Mass and Glucose Homeostasis in Female Mice. JBMR Plus 2021; 5:e10486. [PMID: 33977204 PMCID: PMC8101617 DOI: 10.1002/jbm4.10486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/22/2021] [Accepted: 02/28/2021] [Indexed: 12/11/2022] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) complex is the major nutrient sensor in mammalian cells that responds to amino acids, energy levels, growth factors, and hormones, such as insulin, to control anabolic and catabolic processes. We have recently shown that suppression of the mTORC1 complex in bone‐forming osteoblasts (OBs) improved glucose handling in male mice fed a normal or obesogenic diet. Mechanistically, this occurs, at least in part, by increasing OB insulin sensitivity leading to upregulation of glucose uptake and glycolysis. Given previously reported sex‐dependent differences observed upon antagonism of mTORC1 signaling, we investigated the metabolic and skeletal effects of genetic inactivation of preosteoblastic‐mTORC1 in female mice. Eight‐week‐old control diet (CD)‐fed Rptorob−/− mice had a low bone mass with a significant reduction in trabecular bone volume and trabecular number, reduced cortical bone thickness, and increased marrow adiposity. Despite no changes in body composition, CD‐fed Rptorob−/− mice exhibited significant lower fasting insulin and glucose levels and increased insulin sensitivity. Upon high‐fat diet (HFD) feeding, Rptorob−/− mice were resistant to a diet‐induced increase in whole‐body and total fat mass and protected from the development of diet‐induced insulin resistance. Notably, although 12 weeks of HFD increased marrow adiposity, with minimal changes in both trabecular and cortical bone in the female control mice, marrow adiposity was significantly reduced in HFD‐fed Rptorob−/− compared to both HFD‐fed control and CD‐fed Rptorob−/− mice. Collectively, our results demonstrate that mTORC1 function in preosteoblasts is crucial for skeletal development and skeletal regulation of glucose homeostasis in both male and female mice. Importantly, loss of mTORC1 function in OBs results in metabolic and physiological adaptations that mirror a caloric restriction phenotype (under CD) and protects against HFD‐induced obesity, associated insulin resistance, and marrow adiposity expansion. These results highlight the critical contribution of the skeleton in the regulation of whole‐body energy homeostasis. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Pawanrat Tangseefa
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Sally K Martin
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Agnieszka Arthur
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Vasilios Panagopoulos
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Amanda J Page
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Nutrition, Diabetes & Gut Health Program, Lifelong Health Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Gary A Wittert
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Nutrition, Diabetes & Gut Health Program, Lifelong Health Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia.,Freemasons Foundation Centre for Men's Health University of Adelaide Adelaide South Australia Australia
| | - Christopher G Proud
- Nutrition, Diabetes & Gut Health Program, Lifelong Health Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia.,School of Biological Sciences, University of Adelaide Adelaide South Australia Australia
| | - Stephen Fitter
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia
| | - Andrew C W Zannettino
- Adelaide Medical School, Faculty of Health and Medical Science University of Adelaide Adelaide South Australia Australia.,Cancer Program, Precision Medicine Theme, South Australian Health and Medical Research Institute Adelaide South Australia Australia.,Central Adelaide Local Health Network Adelaide South Australia Australia
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Mirra P, Desiderio A, Spinelli R, Nigro C, Longo M, Parrillo L, D'Esposito V, Carissimo A, Hedjazifar S, Smith U, Formisano P, Miele C, Raciti GA, Beguinot F. Adipocyte precursor cells from first degree relatives of type 2 diabetic patients feature changes in hsa-mir-23a-5p, -193a-5p, and -193b-5p and insulin-like growth factor 2 expression. FASEB J 2021; 35:e21357. [PMID: 33710685 DOI: 10.1096/fj.202002156rrr] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/13/2022]
Abstract
First-degree relatives (FDRs) of type 2 diabetics (T2D) feature dysfunction of subcutaneous adipose tissue (SAT) long before T2D onset. miRNAs have a role in adipocyte precursor cells (APC) differentiation and in adipocyte identity. Thus, impaired miRNA expression may contribute to SAT dysfunction in FDRs. In the present work, we have explored changes in miRNA expression associated with T2D family history which may affect gene expression in SAT APCs from FDRs. Small RNA-seq was performed in APCs from healthy FDRs and matched controls and omics data were validated by qPCR. Integrative analyses of APC miRNome and transcriptome from FDRs revealed down-regulated hsa-miR-23a-5p, -193a-5p and -193b-5p accompanied by up-regulated Insulin-like Growth Factor 2 (IGF2) gene which proved to be their direct target. The expression changes in these marks were associated with SAT adipocyte hypertrophy in FDRs. APCs from FDRs further demonstrated reduced capability to differentiate into adipocytes. Treatment with IGF2 protein decreased APC adipogenesis, while over-expression of hsa-miR-23a-5p, -193a-5p and -193b-5p enhanced adipogenesis by IGF2 targeting. Indeed, IGF2 increased the Wnt Family Member 10B gene expression in APCs. Down-regulation of the three miRNAs and IGF2 up-regulation was also observed in Peripheral Blood Leukocytes (PBLs) from FDRs. In conclusion, APCs from FDRs feature a specific miRNA/gene profile, which associates with SAT adipocyte hypertrophy and appears to contribute to impaired adipogenesis. PBL detection of this profile may help in identifying adipocyte hypertrophy in individuals at high risk of T2D.
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Affiliation(s)
- Paola Mirra
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Antonella Desiderio
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Rosa Spinelli
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Cecilia Nigro
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Michele Longo
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Luca Parrillo
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Vittoria D'Esposito
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | | | - Shahram Hedjazifar
- Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ulf Smith
- Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Pietro Formisano
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Claudia Miele
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Gregory A Raciti
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Francesco Beguinot
- URT Genomics of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Department of Translational Medicine, Federico II University of Naples, Naples, Italy
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Yin S, Liu L, Gan W. The Roles of Post-Translational Modifications on mTOR Signaling. Int J Mol Sci 2021; 22:ijms22041784. [PMID: 33670113 PMCID: PMC7916890 DOI: 10.3390/ijms22041784] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth, proliferation, and metabolism by integrating various environmental inputs including growth factors, nutrients, and energy, among others. mTOR signaling has been demonstrated to control almost all fundamental cellular processes, such as nucleotide, protein and lipid synthesis, autophagy, and apoptosis. Over the past fifteen years, mapping the network of the mTOR pathway has dramatically advanced our understanding of its upstream and downstream signaling. Dysregulation of the mTOR pathway is frequently associated with a variety of human diseases, such as cancers, metabolic diseases, and cardiovascular and neurodegenerative disorders. Besides genetic alterations, aberrancies in post-translational modifications (PTMs) of the mTOR components are the major causes of the aberrant mTOR signaling in a number of pathologies. In this review, we summarize current understanding of PTMs-mediated regulation of mTOR signaling, and also update the progress on targeting the mTOR pathway and PTM-related enzymes for treatment of human diseases.
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The mTORC1 complex in pre-osteoblasts regulates whole-body energy metabolism independently of osteocalcin. Bone Res 2021; 9:10. [PMID: 33551450 PMCID: PMC7868369 DOI: 10.1038/s41413-020-00123-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/23/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Overnutrition causes hyperactivation of mTORC1-dependent negative feedback loops leading to the downregulation of insulin signaling and development of insulin resistance. In osteoblasts (OBs), insulin signaling plays a crucial role in the control of systemic glucose homeostasis. We utilized mice with conditional deletion of Rptor to investigate how the loss of mTORC1 function in OB affects glucose metabolism under normal and overnutrition dietary states. Compared to the controls, chow-fed Rptorob−/− mice had substantially less fat mass and exhibited adipocyte hyperplasia. Remarkably, upon feeding with high-fat diet, mice with pre- and post-natal deletion of Rptor in OBs were protected from diet-induced obesity and exhibited improved glucose metabolism with lower fasting glucose and insulin levels, increased glucose tolerance and insulin sensitivity. This leanness and resistance to weight gain was not attributable to changes in food intake, physical activity or lipid absorption but instead was due to increased energy expenditure and greater whole-body substrate flexibility. RNA-seq revealed an increase in glycolysis and skeletal insulin signaling pathways, which correlated with the potentiation of insulin signaling and increased insulin-dependent glucose uptake in Rptor-knockout osteoblasts. Collectively, these findings point to a critical role for the mTORC1 complex in the skeletal regulation of whole-body glucose metabolism and the skeletal development of insulin resistance.
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Huang LO, Rauch A, Mazzaferro E, Preuss M, Carobbio S, Bayrak CS, Chami N, Wang Z, Schick UM, Yang N, Itan Y, Vidal-Puig A, den Hoed M, Mandrup S, Kilpeläinen TO, Loos RJF. Genome-wide discovery of genetic loci that uncouple excess adiposity from its comorbidities. Nat Metab 2021; 3:228-243. [PMID: 33619380 DOI: 10.1038/s42255-021-00346-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/14/2021] [Indexed: 01/31/2023]
Abstract
Obesity is a major risk factor for cardiometabolic diseases. Nevertheless, a substantial proportion of individuals with obesity do not suffer cardiometabolic comorbidities. The mechanisms that uncouple adiposity from its cardiometabolic complications are not fully understood. Here, we identify 62 loci of which the same allele is significantly associated with both higher adiposity and lower cardiometabolic risk. Functional analyses show that the 62 loci are enriched for genes expressed in adipose tissue, and for regulatory variants that influence nearby genes that affect adipocyte differentiation. Genes prioritized in each locus support a key role of fat distribution (FAM13A, IRS1 and PPARG) and adipocyte function (ALDH2, CCDC92, DNAH10, ESR1, FAM13A, MTOR, PIK3R1 and VEGFB). Several additional mechanisms are involved as well, such as insulin-glucose signalling (ADCY5, ARAP1, CREBBP, FAM13A, MTOR, PEPD, RAC1 and SH2B3), energy expenditure and fatty acid oxidation (IGF2BP2), browning of white adipose tissue (CSK, VEGFA, VEGFB and SLC22A3) and inflammation (SH2B3, DAGLB and ADCY9). Some of these genes may represent therapeutic targets to reduce cardiometabolic risk linked to excess adiposity.
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Affiliation(s)
- Lam O Huang
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Alexander Rauch
- Functional Genomics & Metabolism Research Unit, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Molecular Endocrinology & Stem Cell Research Unit, Department of Endocrinology and Metabolism, Odense University Hospital and Steno Diabetes Center Odense and Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Eugenia Mazzaferro
- The Beijer Laboratory and Department of Immunology, Genetics and Pathology, Uppsala University and SciLifeLab, Uppsala, Sweden
| | - Michael Preuss
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Stefania Carobbio
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Cigdem S Bayrak
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Nathalie Chami
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Zhe Wang
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Ursula M Schick
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Nancy Yang
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Yuval Itan
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Antonio Vidal-Puig
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
- University of Cambridge Metabolic Research Laboratories, Wellcome-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
| | - Marcel den Hoed
- The Beijer Laboratory and Department of Immunology, Genetics and Pathology, Uppsala University and SciLifeLab, Uppsala, Sweden
| | - Susanne Mandrup
- Functional Genomics & Metabolism Research Unit, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Tuomas O Kilpeläinen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA
| | - Ruth J F Loos
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA.
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA.
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, NY, USA.
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Abstract
Sensing and responding to changes in nutrient levels, including those of glucose, lipids, and amino acids, by the body is necessary for survival. Accordingly, perturbations in nutrient sensing are tightly linked with human pathologies, particularly metabolic diseases such as obesity, type 2 diabetes mellitus, and other complications of metabolic syndromes. The conventional view is that amino acids are fundamental elements for protein and peptide synthesis, while recent studies have revealed that amino acids are also important bioactive molecules that play key roles in signaling pathways and metabolic regulation. Different pathways that sense intracellular and extracellular levels of amino acids are integrated and coordinated at the organismal level, and, together, these pathways maintain whole metabolic homeostasis. In this review, we discuss the studies describing how important sensing signals respond to amino acid availability and how these sensing mechanisms modulate metabolic processes, including energy, glucose, and lipid metabolism. We further discuss whether dysregulation of amino acid sensing signals can be targeted to promote metabolic disorders, and discuss how to translate these mechanisms to treat human diseases. This review will help to enhance our overall understanding of the correlation between amino acid sensing and metabolic homeostasis, which have important implications for human health.
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Affiliation(s)
- Xiaoming Hu
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Feifan Guo
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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44
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Ruiz-Ojeda FJ, Wang J, Bäcker T, Krueger M, Zamani S, Rosowski S, Gruber T, Onogi Y, Feuchtinger A, Schulz TJ, Fässler R, Müller TD, García-Cáceres C, Meier M, Blüher M, Ussar S. Active integrins regulate white adipose tissue insulin sensitivity and brown fat thermogenesis. Mol Metab 2021; 45:101147. [PMID: 33359386 PMCID: PMC7808956 DOI: 10.1016/j.molmet.2020.101147] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/20/2022] Open
Abstract
Objective Reorganization of the extracellular matrix is a prerequisite for healthy adipose tissue expansion, whereas fibrosis is a key feature of adipose dysfunction and inflammation. However, very little is known about the direct effects of impaired cell–matrix interaction in adipocyte function and insulin sensitivity. The objective of this study was to determine whether integrin activity can regulate insulin sensitivity in adipocytes and thereby systemic metabolism. Methods We characterized integrin activity in adipose tissue and its consequences on whole-body metabolism using adipose-selective deletion of β1 integrin (Itgb1adipo-cre) and Kindlin-2 (Kind2adipo-cre) in mice. Results We demonstrate that integrin signaling regulates white adipocyte insulin action and systemic metabolism. Consequently, loss of adipose integrin activity, similar to loss of adipose insulin receptors, results in a lipodystrophy-like phenotype and systemic insulin resistance. However, brown adipose tissue of Kind2adipo-cre and Itgb1adipo-cre mice is chronically hyperactivated and has increased substrate delivery, reduced endothelial basement membrane thickness, and increased endothelial vesicular transport. Conclusions Thus, we establish integrin-extracellular matrix interactions as key regulators of white and brown adipose tissue function and whole-body metabolism. β1 and β3 integrins interact with insulin signaling to regulate white adipocyte insulin sensitivity and systemic metabolism. Impaired integrin activity results in lipodystrophy in the absence of hepatosteatosis. β1 integrin activity regulates energy expenditure and vascular permeability in brown adipose tissue.
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Affiliation(s)
- Francisco Javier Ruiz-Ojeda
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Jiefu Wang
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Theresa Bäcker
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Martin Krueger
- Institute for Anatomy, University of Leipzig, 04103, Leipzig, Germany
| | - Samira Zamani
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Simon Rosowski
- Microfluidic and Biological Engineering, Helmholtz Pioneer Campus, Helmholtz Zentrum Munich, 85764, Neuherberg, Germany
| | - Tim Gruber
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Yasuhiro Onogi
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Tim J Schulz
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | - Reinhard Fässler
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Timo D Müller
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, 85764, Neuherberg, Germany; Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
| | - Cristina García-Cáceres
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Matthias Meier
- Microfluidic and Biological Engineering, Helmholtz Pioneer Campus, Helmholtz Zentrum Munich, 85764, Neuherberg, Germany
| | - Matthias Blüher
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Germany
| | - Siegfried Ussar
- RG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Department of Medicine, Technical University Munich, Munich, Germany.
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Orozco JM, Krawczyk PA, Scaria SM, Cangelosi AL, Chan SH, Kunchok T, Lewis CA, Sabatini DM. Dihydroxyacetone phosphate signals glucose availability to mTORC1. Nat Metab 2020; 2:893-901. [PMID: 32719541 PMCID: PMC7995735 DOI: 10.1038/s42255-020-0250-5] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/24/2020] [Indexed: 12/05/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) kinase regulates cell growth by setting the balance between anabolic and catabolic processes. To be active, mTORC1 requires the environmental presence of amino acids and glucose. While a mechanistic understanding of amino acid sensing by mTORC1 is emerging, how glucose activates mTORC1 remains mysterious. Here, we used metabolically engineered human cells lacking the canonical energy sensor AMP-activated protein kinase to identify glucose-derived metabolites required to activate mTORC1 independent of energetic stress. We show that mTORC1 senses a metabolite downstream of the aldolase and upstream of the GAPDH-catalysed steps of glycolysis and pinpoint dihydroxyacetone phosphate (DHAP) as the key molecule. In cells expressing a triose kinase, the synthesis of DHAP from DHA is sufficient to activate mTORC1 even in the absence of glucose. DHAP is a precursor for lipid synthesis, a process under the control of mTORC1, which provides a potential rationale for the sensing of DHAP by mTORC1.
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Affiliation(s)
- Jose M Orozco
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Patrycja A Krawczyk
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sonia M Scaria
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andrew L Cangelosi
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sze Ham Chan
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Tenzin Kunchok
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | | | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA.
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Zhang X, Wu D, Wang C, Luo Y, Ding X, Yang X, Silva F, Arenas S, Weaver JM, Mandell M, Deretic V, Liu M. Sustained activation of autophagy suppresses adipocyte maturation via a lipolysis-dependent mechanism. Autophagy 2020; 16:1668-1682. [PMID: 31840569 PMCID: PMC8386625 DOI: 10.1080/15548627.2019.1703355] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of macroautophagy/autophagy is implicated in obesity and insulin resistance. However, it remains poorly defined how autophagy regulates adipocyte development. Using adipose-specific rptor/raptor knockout (KO), atg7 KO and atg7 rptor double-KO mice, we show that inhibiting MTORC1 by RPTOR deficiency led to autophagic sequestration of lipid droplets, formation of LD-containing lysosomes, and elevation of basal and isoproterenol-induced lipolysis in vivo and in primary adipocytes. Despite normal differentiation at an early phase, progressive degradation and shrinkage of cellular LDs and downregulation of adipogenic markers PPARG and PLIN1 occurred in terminal differentiation of rptor KO adipocytes, which was rescued by inhibiting lipolysis or lysosome. In contrast, inactivating autophagy by depletion of ATG7 protected adipocytes against RPTOR deficiency-induced formation of LD-containing lysosomes, LD degradation, and downregulation of adipogenic markers in vitro. Ultimately, atg7 rptor double-KO mice displayed decreased lipolysis, restored adipose tissue development, and upregulated thermogenic gene expression in brown and inguinal adipose tissue compared to RPTOR-deficient mice in vivo. Collectively, our study demonstrates that autophagy plays an important role in regulating adipocyte maturation via a lipophagy and lipolysis-dependent mechanism. ABBREVIATIONS ATG7: autophagy related 7; BAT: brown adipose tissue; CEBPB/C/EBPβ: CCAAT enhancer binding protein beta; DGAT1: diacylglycerol O-acyltransferase 1; eWAT: epididymal white adipose tissue; iWAT: inguinal white adipose tissue; KO: knockout; LD: lipid droplet; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; PLIN1: perepilin 1; PNPLA2/ATGL: patatin-like phospholipase domain containing 2; PPARG/PPARγ: peroxisome proliferator activated receptor gamma; RPTOR: regulatory associated protein of MTOR complex1; TG: triglyceride; ULK1: unc-51 like kinase 1; UCP1: uncoupling protein 1; WAT: white adipose tissue.
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Affiliation(s)
- Xing Zhang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Dandan Wu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Chunqing Wang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Yan Luo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Xiaofeng Ding
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Xin Yang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Floyd Silva
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Sara Arenas
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - John Michael Weaver
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Michael Mandell
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Vojo Deretic
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Meilian Liu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,CONTACT Meilian Liu Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, USA
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47
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Yamamuro T, Kawabata T, Fukuhara A, Saita S, Nakamura S, Takeshita H, Fujiwara M, Enokidani Y, Yoshida G, Tabata K, Hamasaki M, Kuma A, Yamamoto K, Shimomura I, Yoshimori T. Age-dependent loss of adipose Rubicon promotes metabolic disorders via excess autophagy. Nat Commun 2020; 11:4150. [PMID: 32811819 PMCID: PMC7434891 DOI: 10.1038/s41467-020-17985-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 07/28/2020] [Indexed: 12/31/2022] Open
Abstract
The systemic decline in autophagic activity with age impairs homeostasis in several tissues, leading to age-related diseases. A mechanistic understanding of adipocyte dysfunction with age could help to prevent age-related metabolic disorders, but the role of autophagy in aged adipocytes remains unclear. Here we show that, in contrast to other tissues, aged adipocytes upregulate autophagy due to a decline in the levels of Rubicon, a negative regulator of autophagy. Rubicon knockout in adipocytes causes fat atrophy and hepatic lipid accumulation due to reductions in the expression of adipogenic genes, which can be recovered by activation of PPARγ. SRC-1 and TIF2, coactivators of PPARγ, are degraded by autophagy in a manner that depends on their binding to GABARAP family proteins, and are significantly downregulated in Rubicon-ablated or aged adipocytes. Hence, we propose that age-dependent decline in adipose Rubicon exacerbates metabolic disorders by promoting excess autophagic degradation of SRC-1 and TIF2.
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Affiliation(s)
- Tadashi Yamamuro
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tsuyoshi Kawabata
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
- Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan
| | - Atsunori Fukuhara
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
- Department of Adipose Management, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Shotaro Saita
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Shuhei Nakamura
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, Osaka, Japan
| | - Hikari Takeshita
- Department of Geriatric and General Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mari Fujiwara
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yusuke Enokidani
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Gota Yoshida
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Keisuke Tabata
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Maho Hamasaki
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Akiko Kuma
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Koichi Yamamoto
- Department of Geriatric and General Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Iichiro Shimomura
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan.
- Laboratory of Intracellular Membrane Dynamics, Graduate school of Frontier Biosciences, Osaka University, Osaka, Japan.
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan.
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48
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Samimi Z, Izadpanah A, Feizollahi P, Roghani SA, Assar S, Zafari P, Taghadosi M. The Association between the Plasma Sugar and Lipid Profile with the Gene Expression of the Regulatory Protein of mTOR (Raptor) in Patients with Rheumatoid Arthritis. Immunol Invest 2020; 50:597-608. [PMID: 32576051 DOI: 10.1080/08820139.2020.1781160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Rheumatoid arthritis (RA) is an autoinflammatory and self-perpetuating disease with both articular and extra-articular manifestations, such as cardiovascular complications, which are the leading cause of mortality and morbidity in RA patients. Impaired sugar and lipid metabolism are considered as the critical risk factors for cardiovascular disease (CVD). Regarding the regulatory function of Raptor in the immunometabolism, in this study, we evaluated the association between plasma sugar and lipid profiles with the gene expression of Raptor and the cytokine tumor necrosis factor-α (TNF-α), as an inflammatory mediator, in peripheral blood leukocyte of RA patients. MATERIAL AND METHODS Thirty-five RA patients who received combinational disease modified anti-rheumatoid drugs (DMARD) regimen and thirty healthy subjects enrolled in this study. The gene expression of Raptor was assessed by the real-time PCR method, and the Plasma levels of glucose and lipids, as well as TNF-α, were obtained using Hitachi device and enzyme-linked immunosorbent assay (ELISA) technique, respectively. RESULTS The gene expression of Raptor was reduced significantly in RA patients compared to the healthy subjects (p = .001). The plasma level of HDL was significantly higher in RA patients than the control group (p = .001), while the plasma level of LDL was reduced significantly in these patients (p = .001). CONCLUSION In our study, the reduced gene expression of Raptor may contribute to the impaired immunometabolism in RA patients, which is independent of plasma sugar and lipid profile.
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Affiliation(s)
- Zahra Samimi
- Student Research Committee, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Immunology Department, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Arman Izadpanah
- Student Research Committee, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Immunology Department, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Parisa Feizollahi
- Student Research Committee, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Immunology Department, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Seyed Askar Roghani
- Student Research Committee, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Immunology Department, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Shirin Assar
- Clinical Research Development Center, Imam Reza Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Parisa Zafari
- Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Student Research Committee, Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahdi Taghadosi
- Department of Immunology, Kermanshah University of Medical Sciences, Kermanshah, Iran
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49
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Czech MP. Mechanisms of insulin resistance related to white, beige, and brown adipocytes. Mol Metab 2020; 34:27-42. [PMID: 32180558 PMCID: PMC6997501 DOI: 10.1016/j.molmet.2019.12.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The diminished glucose lowering effect of insulin in obesity, called "insulin resistance," is associated with glucose intolerance, type 2 diabetes, and other serious maladies. Many publications on this topic have suggested numerous hypotheses on the molecular and cellular disruptions that contribute to the syndrome. However, significant uncertainty remains on the mechanisms of its initiation and long-term maintenance. SCOPE OF REVIEW To simplify insulin resistance analysis, this review focuses on the unifying concept that adipose tissue is a central regulator of systemic glucose homeostasis by controlling liver and skeletal muscle metabolism. Key aspects of adipose function related to insulin resistance reviewed are: 1) the modes by which specific adipose tissues control hepatic glucose output and systemic glucose disposal, 2) recently acquired understanding of the underlying mechanisms of these modes of regulation, and 3) the steps in these pathways adversely affected by obesity that cause insulin resistance. MAJOR CONCLUSIONS Adipocyte heterogeneity is required to mediate the multiple pathways that control systemic glucose tolerance. White adipocytes specialize in sequestering triglycerides away from the liver, muscle, and other tissues to limit toxicity. In contrast, brown/beige adipocytes are very active in directly taking up glucose in response to β adrenergic signaling and insulin and enhancing energy expenditure. Nonetheless, white, beige, and brown adipocytes all share the common feature of secreting factors and possibly exosomes that act on distant tissues to control glucose homeostasis. Obesity exerts deleterious effects on each of these adipocyte functions to cause insulin resistance.
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Affiliation(s)
- Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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50
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Liu GY, Sabatini DM. mTOR at the nexus of nutrition, growth, ageing and disease. Nat Rev Mol Cell Biol 2020; 21:183-203. [PMID: 31937935 PMCID: PMC7102936 DOI: 10.1038/s41580-019-0199-y] [Citation(s) in RCA: 1332] [Impact Index Per Article: 333.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2019] [Indexed: 12/21/2022]
Abstract
The mTOR pathway integrates a diverse set of environmental cues, such as growth factor signals and nutritional status, to direct eukaryotic cell growth. Over the past two and a half decades, mapping of the mTOR signalling landscape has revealed that mTOR controls biomass accumulation and metabolism by modulating key cellular processes, including protein synthesis and autophagy. Given the pathway's central role in maintaining cellular and physiological homeostasis, dysregulation of mTOR signalling has been implicated in metabolic disorders, neurodegeneration, cancer and ageing. In this Review, we highlight recent advances in our understanding of the complex regulation of the mTOR pathway and discuss its function in the context of physiology, human disease and pharmacological intervention.
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Affiliation(s)
- Grace Y Liu
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute, Cambridge, MA, USA
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Broad Institute, Cambridge, MA, USA.
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA, USA.
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