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Ajwani J, Hwang E, Portillo B, Lieu L, Wallace B, Kabahizi A, He Z, Dong Y, Grose K, Williams KW. Upregulation of Xbp1 in NPY/AgRP neurons reverses diet-induced obesity and ameliorates leptin and insulin resistance. Neuropeptides 2024; 108:102461. [PMID: 39180950 DOI: 10.1016/j.npep.2024.102461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/31/2024] [Accepted: 08/04/2024] [Indexed: 08/27/2024]
Abstract
The molecular mechanisms underlying neuronal leptin and insulin resistance in obesity and diabetes are not fully understood. In this study, we show that induction of the unfolded protein response transcription factor, spliced X-box binding protein 1 (Xbp1s), in Agouti-Related Peptide (AgRP) neurons alone, is sufficient to not only protect against but also significantly reverse diet-induced obesity (DIO) as well as improve leptin and insulin sensitivity, despite activation of endoplasmic reticulum stress. We also demonstrate that constitutive expression of Xbp1s in AgRP neurons contributes to improved insulin sensitivity and glucose tolerance. Together, our results identify critical molecular mechanisms linking ER stress in arcuate AgRP neurons to acute leptin and insulin resistance as well as liver glucose metabolism in DIO and diabetes.
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Affiliation(s)
- Jason Ajwani
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Eunsang Hwang
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Bryan Portillo
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Linh Lieu
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Briana Wallace
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Anita Kabahizi
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Zhenyan He
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yanbin Dong
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Kyle Grose
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Kevin W Williams
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA.
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2
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Qian Q, Li M, Zhang Z, Davis SW, Rahmouni K, Norris AW, Cao H, Ding WX, Hotamisligil GS, Yang L. Obesity disrupts the pituitary-hepatic UPR communication leading to NAFLD progression. Cell Metab 2024; 36:1550-1565.e9. [PMID: 38718793 PMCID: PMC11222033 DOI: 10.1016/j.cmet.2024.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 03/05/2024] [Accepted: 04/17/2024] [Indexed: 07/05/2024]
Abstract
Obesity alters levels of pituitary hormones that govern hepatic immune-metabolic homeostasis, dysregulation of which leads to nonalcoholic fatty liver disease (NAFLD). However, the impact of obesity on intra-pituitary homeostasis is largely unknown. Here, we uncovered a blunted unfolded protein response (UPR) but elevated inflammatory signatures in pituitary glands of obese mice and humans. Furthermore, we found that obesity inflames the pituitary gland, leading to impaired pituitary inositol-requiring enzyme 1α (IRE1α)-X-box-binding protein 1 (XBP1) UPR branch, which is essential for protecting against pituitary endocrine defects and NAFLD progression. Intriguingly, pituitary IRE1-deletion resulted in hypothyroidism and suppressed the thyroid hormone receptor B (THRB)-mediated activation of Xbp1 in the liver. Conversely, activation of the hepatic THRB-XBP1 axis improved NAFLD in mice with pituitary UPR defect. Our study provides the first evidence and mechanism of obesity-induced intra-pituitary cellular defects and the pathophysiological role of pituitary-liver UPR communication in NAFLD progression.
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Affiliation(s)
- Qingwen Qian
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Mark Li
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Zeyuan Zhang
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Shannon W Davis
- Department of Biological Sciences, College of Arts and Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Andrew W Norris
- Division of Endocrinology and Diabetes, Department of Pediatrics, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Huojun Cao
- Iowa Institute for Oral Health Research, Division of Biostatistics and Computational Biology, Department of Endodontics, University of Iowa College of Dentistry, Iowa City, IA 52242, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Gökhan S Hotamisligil
- Sabri Ülker Center for Metabolic Research, Department of Molecular Metabolism, Harvard T.H. School of Public Health, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02141, USA
| | - Ling Yang
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
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3
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Shen J, Wang X, Wang M, Zhang H. Potential molecular mechanism of exercise reversing insulin resistance and improving neurodegenerative diseases. Front Physiol 2024; 15:1337442. [PMID: 38818523 PMCID: PMC11137309 DOI: 10.3389/fphys.2024.1337442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 04/29/2024] [Indexed: 06/01/2024] Open
Abstract
Neurodegenerative diseases are debilitating nervous system disorders attributed to various conditions such as body aging, gene mutations, genetic factors, and immune system disorders. Prominent neurodegenerative diseases include Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and multiple sclerosis. Insulin resistance refers to the inability of the peripheral and central tissues of the body to respond to insulin and effectively regulate blood sugar levels. Insulin resistance has been observed in various neurodegenerative diseases and has been suggested to induce the occurrence, development, and exacerbation of neurodegenerative diseases. Furthermore, an increasing number of studies have suggested that reversing insulin resistance may be a critical intervention for the treatment of neurodegenerative diseases. Among the numerous measures available to improve insulin sensitivity, exercise is a widely accepted strategy due to its convenience, affordability, and significant impact on increasing insulin sensitivity. This review examines the association between neurodegenerative diseases and insulin resistance and highlights the molecular mechanisms by which exercise can reverse insulin resistance under these conditions. The focus was on regulating insulin resistance through exercise and providing practical ideas and suggestions for future research focused on exercise-induced insulin sensitivity in the context of neurodegenerative diseases.
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Affiliation(s)
- Jiawen Shen
- Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Taizhou, China
| | - Xianping Wang
- School of Medicine, Taizhou University, Taizhou, China
| | - Minghui Wang
- College of Sports Medicine, Wuhan Sports University, Wuhan, China
| | - Hu Zhang
- College of Sports Medicine, Wuhan Sports University, Wuhan, China
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4
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Zhang Y, Chen L, Xuan Y, Zhang L, Tian W, Zhu Y, Wang J, Wang X, Qiu J, Yu J, Tang M, He Z, Zhang H, Chen S, Shen Y, Wang S, Zhang R, Xu L, Ma X, Liao Y, Hu C. Iron overload in hypothalamic AgRP neurons contributes to obesity and related metabolic disorders. Cell Rep 2024; 43:113900. [PMID: 38460132 DOI: 10.1016/j.celrep.2024.113900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/12/2024] [Accepted: 02/15/2024] [Indexed: 03/11/2024] Open
Abstract
Iron overload is closely associated with metabolic dysfunction. However, the role of iron in the hypothalamus remains unclear. Here, we find that hypothalamic iron levels are increased, particularly in agouti-related peptide (AgRP)-expressing neurons in high-fat-diet-fed mice. Using pharmacological or genetic approaches, we reduce iron overload in AgRP neurons by central deferoxamine administration or transferrin receptor 1 (Tfrc) deletion, ameliorating diet-induced obesity and related metabolic dysfunction. Conversely, Tfrc-mediated iron overload in AgRP neurons leads to overeating and adiposity. Mechanistically, the reduction of iron overload in AgRP neurons inhibits AgRP neuron activity; improves insulin and leptin sensitivity; and inhibits iron-induced oxidative stress, endoplasmic reticulum stress, nuclear factor κB signaling, and suppression of cytokine signaling 3 expression. These results highlight the critical role of hypothalamic iron in obesity development and suggest targets for treating obesity and related metabolic disorders.
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Affiliation(s)
- Yi Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Liwei Chen
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Ye Xuan
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Lina Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wen Tian
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Department of Endocrinology, Jinzhou Medical University, Jinzhou 121001, China
| | - Yangyang Zhu
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute for Metabolic Disease, Fengxian Central Hospital Affiliated to Southern Medical University, Shanghai 226001, China
| | - Jinghui Wang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Department of Endocrinology, Xihua Xian People's Hospital, Zhoukou 466000, China
| | - Xinyu Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jin Qiu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jian Yu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Mengyang Tang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute for Metabolic Disease, Fengxian Central Hospital Affiliated to Southern Medical University, Shanghai 226001, China
| | - Zhen He
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Hong Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Si Chen
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Yun Shen
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Siyi Wang
- Department of Pathology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Rong Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Lingyan Xu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China.
| | - Xinran Ma
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China; Chongqing Institute for Brain and Intelligence, Guangyang Bay Laboratory, Chongqing 400064, China.
| | - Yunfei Liao
- Department of Endocrinology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China.
| | - Cheng Hu
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute for Metabolic Disease, Fengxian Central Hospital Affiliated to Southern Medical University, Shanghai 226001, China.
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5
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Mota CMD, Madden CJ. Neural circuits of long-term thermoregulatory adaptations to cold temperatures and metabolic demands. Nat Rev Neurosci 2024; 25:143-158. [PMID: 38316956 DOI: 10.1038/s41583-023-00785-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2023] [Indexed: 02/07/2024]
Abstract
The mammalian brain controls heat generation and heat loss mechanisms that regulate body temperature and energy metabolism. Thermoeffectors include brown adipose tissue, cutaneous blood flow and skeletal muscle, and metabolic energy sources include white adipose tissue. Neural and metabolic pathways modulating the activity and functional plasticity of these mechanisms contribute not only to the optimization of function during acute challenges, such as ambient temperature changes, infection and stress, but also to longitudinal adaptations to environmental and internal changes. Exposure of humans to repeated and seasonal cold ambient conditions leads to adaptations in thermoeffectors such as habituation of cutaneous vasoconstriction and shivering. In animals that undergo hibernation and torpor, neurally regulated metabolic and thermoregulatory adaptations enable survival during periods of significant reduction in metabolic rate. In addition, changes in diet can activate accessory neural pathways that alter thermoeffector activity. This knowledge may be harnessed for therapeutic purposes, including treatments for obesity and improved means of therapeutic hypothermia.
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Affiliation(s)
- Clarissa M D Mota
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA.
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6
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Mao H, Kim GH, Qi L. SEL1L-HRD1 ER-associated degradation regulates leptin receptor maturation and signaling in POMC neurons in diet-induced obesity. RESEARCH SQUARE 2024:rs.3.rs-3768472. [PMID: 38260335 PMCID: PMC10802724 DOI: 10.21203/rs.3.rs-3768472/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Endoplasmic reticulum (ER) homeostasis in the hypothalamus has been implicated in the pathogenesis of certain patho-physiological conditions such as diet-induced obesity (DIO) and type 2 diabetes; however, the significance of ER quality control mechanism(s) and its underlying mechanism remain largely unclear and highly controversial in some cases. Moreover, how the biogenesis of nascent leptin receptor in the ER is regulated remains largely unexplored. Here we report that the SEL1L-HRD1 protein complex of the highly conserved ER-associated protein degradation (ERAD) machinery in POMC neurons is indispensable for leptin signaling in diet-induced obesity. SEL1L-HRD1 ERAD is constitutively expressed in hypothalamic POMC neurons. Loss of SEL1L in POMC neurons attenuates leptin signaling and predisposes mice to HFD-associated pathologies including leptin resistance. Mechanistically, newly synthesized leptin receptors, both wildtype and disease-associated human mutant Cys604Ser (Cys602Ser in mice), are misfolding prone and bona fide substrates of SEL1L-HRD1 ERAD. Indeed, defects in SEL1L-HRD1 ERAD markedly impair the maturation of these receptors and causes their ER retention. This study not only uncovers a new role of SEL1L-HRD1 ERAD in the pathogenesis of diet-induced obesity and central leptin resistance, but a new regulatory mechanism for leptin signaling.
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Affiliation(s)
- Hancheng Mao
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105, USA
| | - Geun Hyang Kim
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105, USA
- Present address: Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Ling Qi
- Department of Molecular Physiology and Biological Physics, University of Virginia, School of Medicine, Charlottesville, VA 22903, USA
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7
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Dragano NRV, Milbank E, Haddad-Tóvolli R, Garrido-Gil P, Nóvoa E, Fondevilla MF, Capelli V, Zanesco AM, Solon C, Morari J, Pires L, Estevez-Salguero Á, Beiroa D, González-García I, Barca-Mayo O, Diéguez C, Nogueiras R, Labandeira-García JL, Rexen Ulven E, Ulven T, Claret M, Velloso LA, López M. Hypothalamic free fatty acid receptor-1 regulates whole-body energy balance. Mol Metab 2024; 79:101840. [PMID: 38036170 PMCID: PMC10784317 DOI: 10.1016/j.molmet.2023.101840] [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: 11/09/2023] [Accepted: 11/17/2023] [Indexed: 12/02/2023] Open
Abstract
OBJECTIVE Free fatty acid receptor-1 (FFAR1) is a medium- and long-chain fatty acid sensing G protein-coupled receptor that is highly expressed in the hypothalamus. Here, we investigated the central role of FFAR1 on energy balance. METHODS Central FFAR1 agonism and virogenic knockdown were performed in mice. Energy balance studies, infrared thermographic analysis of brown adipose tissue (BAT) and molecular analysis of the hypothalamus, BAT, white adipose tissue (WAT) and liver were carried out. RESULTS Pharmacological stimulation of FFAR1, using central administration of its agonist TUG-905 in diet-induced obese mice, decreases body weight and is associated with increased energy expenditure, BAT thermogenesis and browning of subcutaneous WAT (sWAT), as well as reduced AMP-activated protein kinase (AMPK) levels, reduced inflammation, and decreased endoplasmic reticulum (ER) stress in the hypothalamus. As FFAR1 is expressed in distinct hypothalamic neuronal subpopulations, we used an AAV vector expressing a shRNA to specifically knockdown Ffar1 in proopiomelanocortin (POMC) neurons of the arcuate nucleus of the hypothalamus (ARC) of obese mice. Our data showed that knockdown of Ffar1 in POMC neurons promoted hyperphagia and body weight gain. In parallel, these mice developed hepatic insulin resistance and steatosis. CONCLUSIONS FFAR1 emerges as a new hypothalamic nutrient sensor regulating whole body energy balance. Moreover, pharmacological activation of FFAR1 could provide a therapeutic advance in the management of obesity and its associated metabolic disorders.
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Affiliation(s)
- Nathalia R V Dragano
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain; Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil.
| | - Edward Milbank
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Roberta Haddad-Tóvolli
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Pablo Garrido-Gil
- Department of Morphological Sciences, CiMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; CIBER Enfermedades Neurodegenerativas (CIBERNED), 28029, Santiago de Compostela, Spain
| | - Eva Nóvoa
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Marcos F Fondevilla
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Valentina Capelli
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Ariane Maria Zanesco
- Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Carina Solon
- Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Joseane Morari
- Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Leticia Pires
- Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Ánxela Estevez-Salguero
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Daniel Beiroa
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Ismael González-García
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Olga Barca-Mayo
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - Carlos Diéguez
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - Ruben Nogueiras
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain
| | - José L Labandeira-García
- Department of Morphological Sciences, CiMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; CIBER Enfermedades Neurodegenerativas (CIBERNED), 28029, Santiago de Compostela, Spain
| | - Elisabeth Rexen Ulven
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Trond Ulven
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Marc Claret
- Neuronal Control of Metabolism (NeuCoMe) Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; CIBER Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem), 08036, Spain; Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Licio A Velloso
- Laboratory of Cell Signaling-Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
| | - Miguel López
- Department of Physiology, CiMUS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 15706, Spain.
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8
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Li Y, Zhu S, Du D, Li Q, Xie K, Chen L, Feng X, Wu X, Sun Z, Zhou J, Yang J, Shu G, Wang S, Gao P, Zhu C, Jiang Q, Wang L. TLR4 in POMC neurons regulates thermogenesis in a sex-dependent manner. J Lipid Res 2023; 64:100368. [PMID: 37028769 PMCID: PMC10205441 DOI: 10.1016/j.jlr.2023.100368] [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: 10/08/2022] [Revised: 02/10/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023] Open
Abstract
The rising prevalence of obesity has become a worldwide health concern. Obesity usually occurs when there is an imbalance between energy intake and energy expenditure. However, energy expenditure consists of several components, including metabolism, physical activity, and thermogenesis. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor, and it is abundantly expressed in the brain. Here, we showed that pro-opiomelanocortin (POMC)-specific deficiency of TLR4 directly modulates brown adipose tissue thermogenesis and lipid homeostasis in a sex-dependent manner. Deleting TLR4 in POMC neurons is sufficient to increase energy expenditure and thermogenesis resulting in reduced body weight in male mice. POMC neuron is a subpopulation of tyrosine hydroxylase neurons and projects into brown adipose tissue, which regulates the activity of sympathetic nervous system and contributes to thermogenesis in POMC-TLR4-KO male mice. By contrast, deleting TLR4 in POMC neurons decreases energy expenditure and increases body weight in female mice, which affects lipolysis of white adipose tissue (WAT). Mechanistically, TLR4 KO decreases the expression of the adipose triglyceride lipase and lipolytic enzyme hormone-sensitive lipase in WAT in female mice. Furthermore, the function of immune-related signaling pathway in WAT is inhibited because of obesity, which exacerbates the development of obesity reversely. Together, these results demonstrate that TLR4 in POMC neurons regulates thermogenesis and lipid balance in a sex-dependent manner.
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Affiliation(s)
- Yongxiang Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Shuqing Zhu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Dan Du
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Qiyong Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Kailai Xie
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Lvshuang Chen
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiajie Feng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xin Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Zhonghua Sun
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jingjing Zhou
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jinping Yang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Gang Shu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Songbo Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Ping Gao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Canjun Zhu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
| | - Qingyan Jiang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
| | - Lina Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, South China Agricultural University, Guangzhou, Guangdong, China; National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
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9
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Tang Q, Liu Q, Li J, Yan J, Jing X, Zhang J, Xia Y, Xu Y, Li Y, He J. MANF in POMC Neurons Promotes Brown Adipose Tissue Thermogenesis and Protects Against Diet-Induced Obesity. Diabetes 2022; 71:2344-2359. [PMID: 35972224 PMCID: PMC9630086 DOI: 10.2337/db21-1128] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 08/07/2022] [Indexed: 01/25/2023]
Abstract
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an emerging regulator in metabolic control. Hypothalamic proopiomelanocortin (POMC) neurons play critical roles in maintaining whole-body energy homeostasis. Whether MANF in POMC neurons is required for the proper regulation of energy balance remains unknown. Here, we showed that mice lacking MANF in POMC neurons were more prone to develop diet-induced obesity. In addition, the ablation of MANF induced endoplasmic reticulum (ER) stress and leptin resistance in the hypothalamus, reduced POMC expression and posttranslational processing, and ultimately decreased sympathetic nerve activity and thermogenesis in brown adipose tissue (BAT). Conversely, MANF overexpression in hypothalamic POMC neurons attenuated ER stress, increased POMC expression and processing, and then stimulated sympathetic innervation and activity in BAT, resulting in increased BAT thermogenesis, thus protecting mice against dietary obesity. Overall, our findings provide evidence that MANF is required for POMC neurons to combat obesity.
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Affiliation(s)
- Qin Tang
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
| | - Qinhui Liu
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
| | - Jiahui Li
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jiamin Yan
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiandan Jing
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
| | - Jinhang Zhang
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yan Xia
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Xu
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yanping Li
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
| | - Jinhan He
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, China
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- Corresponding author: Jinhan He,
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10
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Pei Z, He Y, Bean JC, Yang Y, Liu H, Yu M, Yu K, Hyseni I, Cai X, Liu H, Qu N, Tu L, Conde KM, Wang M, Li Y, Yin N, Zhang N, Han J, Potts CHS, Scarcelli NA, Yan Z, Xu P, Wu Q, He Y, Xu Y, Wang C. Gabra5 plays a sexually dimorphic role in POMC neuron activity and glucose balance. Front Endocrinol (Lausanne) 2022; 13:889122. [PMID: 36120438 PMCID: PMC9471380 DOI: 10.3389/fendo.2022.889122] [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: 03/03/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022] Open
Abstract
Pro-opiomelanocortin (POMC) neurons are important for the regulation of body weight and glucose balance. The inhibitory tone to POMC neurons is mediated primarily by the GABA receptors. However, the detailed mechanisms and functions of GABA receptors are not well understood. The α5 subunit of GABAA receptor, Gabra5, is reported to regulate feeding, and we found that Gabra5 is highly expressed in POMC neurons. To explore the function of Gabra5 in POMC neurons, we knocked down Gabra5 specifically from mature hypothalamic POMC neurons using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 strategy. This POMC-specific knock-down of Gabra5 did not affect body weight or food intake in either male or female mice. Interestingly, the loss of Gabra5 caused significant increases in the firing frequency and resting membrane potential, and a decrease in the amplitude of the miniature inhibitory postsynaptic current (mIPSC) in male POMC neurons. However, the loss of Gabra5 only modestly decreased the frequency of mIPSC in female POMC neurons. Consistently, POMC-specific knock-down of Gabra5 significantly improved glucose tolerance in male mice but not in female mice. These results revealed a sexually dimorphic role of Gabra5 in POMC neuron activity and glucose balance, independent of body weight control.
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Affiliation(s)
- Zhou Pei
- Department of Endocrinology and Inherited Metabolic Diseases, Children’s Hospital of Fudan University, Shanghai, China
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yang He
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Jonathan C. Bean
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yongjie Yang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Hailan Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Meng Yu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Kaifan Yu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Ilirjana Hyseni
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Xing Cai
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Hesong Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Na Qu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Longlong Tu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Kristine M. Conde
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Mengjie Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yongxiang Li
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Na Yin
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Nan Zhang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Junying Han
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Camille HS. Potts
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Nikolas A. Scarcelli
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Zili Yan
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Pingwen Xu
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL, United States
| | - Qi Wu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Yanlin He
- Pennington Biomedical Research Center, Brain Glycemic and Metabolism Control Department, Louisiana State University, Baton Rouge, LA, United States
| | - Yong Xu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
| | - Chunmei Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
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11
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Signaling pathways in obesity: mechanisms and therapeutic interventions. Signal Transduct Target Ther 2022; 7:298. [PMID: 36031641 PMCID: PMC9420733 DOI: 10.1038/s41392-022-01149-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 12/19/2022] Open
Abstract
Obesity is a complex, chronic disease and global public health challenge. Characterized by excessive fat accumulation in the body, obesity sharply increases the risk of several diseases, such as type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease, and is linked to lower life expectancy. Although lifestyle intervention (diet and exercise) has remarkable effects on weight management, achieving long-term success at weight loss is extremely challenging, and the prevalence of obesity continues to rise worldwide. Over the past decades, the pathophysiology of obesity has been extensively investigated, and an increasing number of signal transduction pathways have been implicated in obesity, making it possible to fight obesity in a more effective and precise way. In this review, we summarize recent advances in the pathogenesis of obesity from both experimental and clinical studies, focusing on signaling pathways and their roles in the regulation of food intake, glucose homeostasis, adipogenesis, thermogenesis, and chronic inflammation. We also discuss the current anti-obesity drugs, as well as weight loss compounds in clinical trials, that target these signals. The evolving knowledge of signaling transduction may shed light on the future direction of obesity research, as we move into a new era of precision medicine.
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12
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Zhao J, Hu L, Gui W, Xiao L, Wang W, Xia J, Fan H, Li Z, Zhu Q, Hou X, Chu H, Seki E, Yang L. Hepatocyte TGF-β Signaling Inhibiting WAT Browning to Promote NAFLD and Obesity Is Associated With Let-7b-5p. Hepatol Commun 2022; 6:1301-1321. [PMID: 35018737 PMCID: PMC9134819 DOI: 10.1002/hep4.1892] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/06/2021] [Accepted: 12/18/2021] [Indexed: 01/18/2023] Open
Abstract
Transforming growth factor beta (TGF-β) signaling in hepatocytes promotes steatosis and body weight gain. However, processes that TGF-β signaling in hepatocytes promote pathological body weight gain in nonalcoholic fatty liver disease (NAFLD) are incompletely understood. Obesity and NAFLD were induced by 16 weeks of feeding a high-fat diet (HFD) in hepatocyte-specific TGF-β receptor II-deficient (Tgfbr2ΔHEP ) and Tgfbr2flox/flox mice. In addition, browning of white adipose tissue (WAT) was induced by administration of CL-316,243 (a β3-adrenergic agonist) or cold exposure for 7 days. Compared with Tgfbr2 flox/flox mice, Tgfbr2ΔHEP mice were resistant to steatosis and obesity. The metabolic changes in Tgfbr2ΔHEP mice were due to the increase of mitochondrial oxidative phosphorylation in the liver and white-to-beige fat conversion. A further mechanistic study revealed that exosomal let-7b-5p derived from hepatocytes was robustly elevated after stimulation with palmitic acid and TGF-β. Indeed, let-7b-5p levels were low in the liver, serum exosomes, inguinal WAT, and epididymal WAT in HFD-fed Tgfbr2ΔHEP mice. Moreover, 3T3-L1 cells internalized hepatocyte-derived exosomes. An in vitro experiment demonstrated that let-7b-5p overexpression increased hepatocyte fatty acid transport and inhibited adipocyte-like cell thermogenesis, whereas let-7b-5p inhibitor exerted the opposite effects. Conclusion: Hepatocyte TGF-β-let-7b-5p signaling promotes HFD-induced steatosis and obesity by reducing mitochondrial oxidative phosphorylation and suppressing white-to-beige fat conversion. This effect of hepatocyte TGF-β signaling in metabolism is partially associated with exosomal let-7b-5p.
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Affiliation(s)
- Jinfang Zhao
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Lilin Hu
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Wenfang Gui
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Li Xiao
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Weijun Wang
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Jing Xia
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Huiqian Fan
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Zhonglin Li
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | | | - Xiaohua Hou
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Huikuan Chu
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Ekihiro Seki
- Karsh Division of Gastroenterology and HepatologyCedars-Sinai Medical CenterLos AngelesCAUSA
| | - Ling Yang
- Division of GastroenterologyUnion HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
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13
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Tran LT, Park S, Kim SK, Lee JS, Kim KW, Kwon O. Hypothalamic control of energy expenditure and thermogenesis. Exp Mol Med 2022; 54:358-369. [PMID: 35301430 PMCID: PMC9076616 DOI: 10.1038/s12276-022-00741-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 12/05/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Energy expenditure and energy intake need to be balanced to maintain proper energy homeostasis. Energy homeostasis is tightly regulated by the central nervous system, and the hypothalamus is the primary center for the regulation of energy balance. The hypothalamus exerts its effect through both humoral and neuronal mechanisms, and each hypothalamic area has a distinct role in the regulation of energy expenditure. Recent studies have advanced the understanding of the molecular regulation of energy expenditure and thermogenesis in the hypothalamus with targeted manipulation techniques of the mouse genome and neuronal function. In this review, we elucidate recent progress in understanding the mechanism of how the hypothalamus affects basal metabolism, modulates physical activity, and adapts to environmental temperature and food intake changes. The hypothalamus is a key regulator of metabolism, controlling resting metabolism, activity levels, and responses to external temperature and food intake. The balance between energy intake and expenditure must be tightly controlled, with imbalances resulting in metabolic disorders such as obesity or diabetes. Obin Kwon at Seoul National University College of Medicine and Ki Woo Kim at Yonsei University College of Dentistry, Seoul, both in South Korea, and coworkers reviewed how metabolism is regulated by the hypothalamus, a small hormone-producing brain region. They report that hormonal and neuronal signals from the hypothalamus influence the ratio of lean to fatty tissue, gender-based differences in metabolism, activity levels, and weight gain in response to food intake. They note that further studies to untangle cause-and-effect relationships and other genetic factors will improve our understanding of metabolic regulation.
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Affiliation(s)
- Le Trung Tran
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Sohee Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Seul Ki Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea
| | - Jin Sun Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Ki Woo Kim
- Departments of Oral Biology and Applied Biological Science, BK21 Four, Yonsei University College of Dentistry, Seoul, 03722, Korea.
| | - Obin Kwon
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea. .,Departments of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.
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14
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McLaughlin T, Medina A, Perkins J, Yera M, Wang JJ, Zhang SX. Cellular stress signaling and the unfolded protein response in retinal degeneration: mechanisms and therapeutic implications. Mol Neurodegener 2022; 17:25. [PMID: 35346303 PMCID: PMC8962104 DOI: 10.1186/s13024-022-00528-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/04/2022] [Indexed: 12/22/2022] Open
Abstract
Background The retina, as part of the central nervous system (CNS) with limited capacity for self-reparation and regeneration in mammals, is under cumulative environmental stress due to high-energy demands and rapid protein turnover. These stressors disrupt the cellular protein and metabolic homeostasis, which, if not alleviated, can lead to dysfunction and cell death of retinal neurons. One primary cellular stress response is the highly conserved unfolded protein response (UPR). The UPR acts through three main signaling pathways in an attempt to restore the protein homeostasis in the endoplasmic reticulum (ER) by various means, including but not limited to, reducing protein translation, increasing protein-folding capacity, and promoting misfolded protein degradation. Moreover, recent work has identified a novel function of the UPR in regulation of cellular metabolism and mitochondrial function, disturbance of which contributes to neuronal degeneration and dysfunction. The role of the UPR in retinal neurons during aging and under disease conditions in age-related macular degeneration (AMD), retinitis pigmentosa (RP), glaucoma, and diabetic retinopathy (DR) has been explored over the past two decades. Each of the disease conditions and their corresponding animal models provide distinct challenges and unique opportunities to gain a better understanding of the role of the UPR in the maintenance of retinal health and function. Method We performed an extensive literature search on PubMed and Google Scholar using the following keywords: unfolded protein response, metabolism, ER stress, retinal degeneration, aging, age-related macular degeneration, retinitis pigmentosa, glaucoma, diabetic retinopathy. Results and conclusion We summarize recent advances in understanding cellular stress response, in particular the UPR, in retinal diseases, highlighting the potential roles of UPR pathways in regulation of cellular metabolism and mitochondrial function in retinal neurons. Further, we provide perspective on the promise and challenges for targeting the UPR pathways as a new therapeutic approach in age- and disease-related retinal degeneration.
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Affiliation(s)
- Todd McLaughlin
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Andy Medina
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Jacob Perkins
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA
| | - Maria Yera
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA.,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Joshua J Wang
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA.,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Sarah X Zhang
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 955 Main Street, Buffalo, NY, 14203, USA. .,Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA. .,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
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15
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Los posibles mecanismos de pardeamiento del tejido adiposo blanco: una diana novedosa para el tratamiento de la obesidad. NUTR HOSP 2022; 39:411-424. [PMID: 35001637 DOI: 10.20960/nh.03852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The increase of the obesity pandemic worldwide over the last several decades has generated a constant need for the scientific world to develop new possibilities to combat obesity. Since the discovery that brown adipose tissue (BAT) exists in adult humans, and BAT activation contributes to a negative energy balance, much more attention has been focused on the understanding of the molecular switches and their different regulatory mechanisms turning on energy expenditure. Recent insights have revealed that a range of stimuli including cold exposure, physical activity and diet, and critical transcription molecules such as PPARγ, PRDM16, PGC-1α and UCP1, aiming at the induction of BAT activation, could cause the browning of white adipose tissue, thereby dissipating energy and increasing heat production. An increasing number of studies that point to the white adipose tissue (WAT) browning strategies aiming at diet-induced and/or genetically determined obesity have been tested in mouse models as well as in human studies. Findings suggested that browning stimulating drugs have been currently or previously assayed as a therapy against obesity. As PPARα agonists, fibrate drugs effectively reduced plasma triglyceride, increased high-density lipoproteins, and improved glycemic control and heat production in brown adipose tissue, which has been used in the treatment of metabolic disorders. Many kinds of natural products promote white adipose tissue browning, such as alkaloids, flavonoids, terpenoids, and long-chain fatty acids, which can also ameliorate metabolic disorders including obesity, insulin resistance and diabetes. The aim of this review is to summarize the transcriptional regulators as well as the various mediators that have been regarded as potential therapeutic targets in the process of WAT browning.
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16
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Yang D, Hou X, Yang G, Li M, Zhang J, Han M, Zhang Y, Liu Y. Effects of the POMC System on Glucose Homeostasis and Potential Therapeutic Targets for Obesity and Diabetes. Diabetes Metab Syndr Obes 2022; 15:2939-2950. [PMID: 36186941 PMCID: PMC9521683 DOI: 10.2147/dmso.s380577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/13/2022] [Indexed: 11/23/2022] Open
Abstract
The hypothalamus is indispensable in energy regulation and glucose homeostasis. Previous studies have shown that pro-opiomelanocortin neurons receive both central neuronal signals, such as α-melanocyte-stimulating hormone, β-endorphin, and adrenocorticotropic hormone, as well as sense peripheral signals such as leptin, insulin, adiponectin, glucagon-like peptide-1, and glucagon-like peptide-2, affecting glucose metabolism through their corresponding receptors and related signaling pathways. Abnormalities in these processes can lead to obesity, type 2 diabetes, and other metabolic diseases. However, the mechanisms by which these signal molecules fulfill their role remain unclear. Consequently, in this review, we explored the mechanisms of these hormones and signals on obesity and diabetes to suggest potential therapeutic targets for obesity-related metabolic diseases. Multi-drug combination therapy for obesity and diabetes is becoming a trend and requires further research to help patients to better control their blood glucose and improve their prognosis.
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Affiliation(s)
- Dan Yang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Xintong Hou
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Guimei Yang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Mengnan Li
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Jian Zhang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Minmin Han
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- First Clinical Medical College, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Yi Zhang
- Department of Pharmacology, Shanxi Medical University, Taiyuan, People’s Republic of China
- Correspondence: Yi Zhang, Department of Pharmacology, Shanxi Medical University, Taiyuan, People’s Republic of China, Email
| | - Yunfeng Liu
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
- Yunfeng Liu, Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China, Tel +86 18703416196, Email
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17
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Cavalcanti-de-Albuquerque JP, Donato J. Rolling out physical exercise and energy homeostasis: Focus on hypothalamic circuitries. Front Neuroendocrinol 2021; 63:100944. [PMID: 34425188 DOI: 10.1016/j.yfrne.2021.100944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/11/2021] [Accepted: 08/18/2021] [Indexed: 01/17/2023]
Abstract
Energy balance is the fine regulation of energy expenditure and energy intake. Negative energy balance causes body weight loss, while positive energy balance promotes weight gain. Modern societies offer a maladapted way of life, where easy access to palatable foods and the lack of opportunities to perform physical activity are considered the roots of the obesity pandemic. Physical exercise increases energy expenditure and, consequently, is supposed to promote weight loss. Paradoxically, physical exercise acutely drives anorexigenic-like effects, but the mechanisms are still poorly understood. Using an evolutionary background, this review aims to highlight the potential involvement of the melanocortin system and other hypothalamic neural circuitries regulating energy balance during and after physical exercise. The physiological significance of these changes will be explored, and possible signalling agents will be addressed. The knowledge discussed here might be important for clarifying obesity aetiology as well as new therapeutic approaches for body weight loss.
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Affiliation(s)
| | - José Donato
- Department of Physiology and Biophysics, University of São Paulo, São Paulo 05508-900, Brazil.
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18
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He Z, Lieu L, Dong Y, Afrin S, Chau D, Kabahizi A, Wallace B, Cao J, Hwang ES, Yao T, Huang Y, Okolo J, Cheng B, Gao Y, Hu L, Williams KW. PERK in POMC neurons connects celastrol with metabolism. JCI Insight 2021; 6:145306. [PMID: 34549728 PMCID: PMC8492333 DOI: 10.1172/jci.insight.145306] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 07/28/2021] [Indexed: 01/02/2023] Open
Abstract
ER stress and activation of the unfolded protein response in the periphery as well as the central nervous system have been linked to various metabolic abnormalities. Chemically lowering protein kinase R–like ER kinase (PERK) activity within the hypothalamus leads to decreased food intake and body weight. However, the cell populations required in this response remain undefined. In the current study, we investigated the effects of proopiomelanocortin-specific (POMC-specific) PERK deficiency on energy balance and glucose metabolism. Male mice deficient for PERK in POMC neurons exhibited improvements in energy balance on a high-fat diet, showing decreased food intake and body weight, independent of changes in glucose and insulin tolerances. The plant-based inhibitor of PERK, celastrol, increases leptin sensitivity, resulting in decreased food intake and body weight in a murine model of diet-induced obesity (DIO). Our data extend these observations by demonstrating that celastrol-induced improvements in leptin sensitivity and energy balance were attenuated in mice with PERK deficiency in POMC neurons. Altogether, these data suggest that POMC-specific PERK deficiency in male mice confers protection against DIO, possibly providing a new therapeutic target for the treatment of diabetes and metabolic syndrome.
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Affiliation(s)
- Zhenyan He
- Department of Neurosurgery, Affiliated Tumor Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Linh Lieu
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Yanbin Dong
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA.,Institute of Gastroenterology and.,Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Sadia Afrin
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Dominic Chau
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Anita Kabahizi
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Briana Wallace
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Jianhong Cao
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Eun-Sang Hwang
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Ting Yao
- Division of Pediatric Endocrinology, Department of Pediatrics, UCLA Children's Discovery and Innovation Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Yiru Huang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Jennifer Okolo
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Bo Cheng
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Yong Gao
- Laboratory Department, Affiliated Hospital of Binzhou Medical College, Shandong, China
| | - Ling Hu
- Institute of Gastroenterology and.,Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Kevin W Williams
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
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19
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Abstract
Obesity, which has long since reached epidemic proportions worldwide, is associated with long-term stress to a variety of organs and results in diseases including type 2 diabetes. In the brain, overnutrition induces hypothalamic stress associated with the activation of several signalling pathways, together with central insulin and leptin resistance. This central action of nutrient overload appears very rapidly, suggesting that nutrition-induced hypothalamic stress is a major upstream initiator of obesity and associated diseases. The cellular response to nutrient overload includes the activation of the stress-activated c-Jun N-terminal kinases (JNKs) JNK1, JNK2 and JNK3, which are widely expressed in the brain. Here, we review recent findings on the regulation and effects of these kinases, with particular focus on the hypothalamus, a key brain region in the control of energy and glucose homeostasis. JNK1 blocks the hypothalamic-pituitary-thyroid axis, reducing energy expenditure and promoting obesity. Recently, opposing roles have been identified for JNK1 and JNK3 in hypothalamic agouti gene-related protein (AgRP) neurons: while JNK1 activation in AgRP neurons induces feeding and weight gain and impairs insulin and leptin signalling, JNK3 (also known as MAPK10) deletion in the same neuronal population produces very similar effects. The opposing roles of these kinases, and the unknown role of hypothalamic JNK2, reflect the complexity of JNK biology. Future studies should address the specific function of each kinase, not only in different neuronal subsets, but also in non-neuronal cells in the central nervous system. Decoding the puzzle of brain stress kinases will help to define the central stimuli and mechanisms implicated in the control of energy balance. Graphical abstract.
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Affiliation(s)
- Rubén Nogueiras
- Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
- Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, Spain
| | - Guadalupe Sabio
- Department of Myocardial Pathophysiology, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain.
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20
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Medinas DB, Hazari Y, Hetz C. Disruption of Endoplasmic Reticulum Proteostasis in Age-Related Nervous System Disorders. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:239-278. [PMID: 34050870 DOI: 10.1007/978-3-030-67696-4_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Endoplasmic reticulum (ER) stress is a prominent cellular alteration of diseases impacting the nervous system that are associated to the accumulation of misfolded and aggregated protein species during aging. The unfolded protein response (UPR) is the main pathway mediating adaptation to ER stress, but it can also trigger deleterious cascades of inflammation and cell death leading to cell dysfunction and neurodegeneration. Genetic and pharmacological studies in experimental models shed light into molecular pathways possibly contributing to ER stress and the UPR activation in human neuropathies. Most of experimental models are, however, based on the overexpression of mutant proteins causing familial forms of these diseases or the administration of neurotoxins that induce pathology in young animals. Whether the mechanisms uncovered in these models are relevant for the etiology of the vast majority of age-related sporadic forms of neurodegenerative diseases is an open question. Here, we provide a systematic analysis of the current evidence linking ER stress to human pathology and the main mechanisms elucidated in experimental models. Furthermore, we highlight the recent association of metabolic syndrome to increased risk to undergo neurodegeneration, where ER stress arises as a common denominator in the pathogenic crosstalk between peripheral organs and the nervous system.
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Affiliation(s)
- Danilo B Medinas
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile. .,Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile. .,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
| | - Younis Hazari
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile. .,Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile. .,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile. .,Buck Institute for Research on Aging, Novato, CA, USA.
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21
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Calió ML, Henriques E, Siena A, Bertoncini CRA, Gil-Mohapel J, Rosenstock TR. Mitochondrial Dysfunction, Neurogenesis, and Epigenetics: Putative Implications for Amyotrophic Lateral Sclerosis Neurodegeneration and Treatment. Front Neurosci 2020; 14:679. [PMID: 32760239 PMCID: PMC7373761 DOI: 10.3389/fnins.2020.00679] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/03/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive and devastating multifactorial neurodegenerative disorder. Although the pathogenesis of ALS is still not completely understood, numerous studies suggest that mitochondrial deregulation may be implicated in its onset and progression. Interestingly, mitochondrial deregulation has also been associated with changes in neural stem cells (NSC) proliferation, differentiation, and migration. In this review, we highlight the importance of mitochondrial function for neurogenesis, and how both processes are correlated and may contribute to the pathogenesis of ALS; we have focused primarily on preclinical data from animal models of ALS, since to date no studies have evaluated this link using human samples. As there is currently no cure and no effective therapy to counteract ALS, we have also discussed how improving neurogenic function by epigenetic modulation could benefit ALS. In support of this hypothesis, changes in histone deacetylation can alter mitochondrial function, which in turn might ameliorate cellular proliferation as well as neuronal differentiation and migration. We propose that modulation of epigenetics, mitochondrial function, and neurogenesis might provide new hope for ALS patients, and studies exploring these new territories are warranted in the near future.
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Affiliation(s)
| | - Elisandra Henriques
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | - Amanda Siena
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | - Clélia Rejane Antonio Bertoncini
- CEDEME, Center of Development of Experimental Models for Medicine and Biology, Federal University of São Paulo, São Paulo, Brazil
| | - Joana Gil-Mohapel
- Division of Medical Sciences, Faculty of Medicine, University of Victoria and Island Medical Program, University of British Columbia, Victoria, BC, Canada
| | - Tatiana Rosado Rosenstock
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
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22
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Tang Q, Gao Y, Liu Q, Yang X, Wu T, Huang C, Huang Y, Zhang J, Zhang Z, Li R, Pu S, Zhang G, Zhao Y, Zhou J, Huang H, Li Y, Jiang W, Chang Y, He J. Sirt6 in pro-opiomelanocortin neurons controls energy metabolism by modulating leptin signaling. Mol Metab 2020; 37:100994. [PMID: 32278654 PMCID: PMC7215198 DOI: 10.1016/j.molmet.2020.100994] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/28/2020] [Accepted: 04/03/2020] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE Sirt6 is an essential regulator of energy metabolism in multiple peripheral tissues. However, the direct role of Sirt6 in the hypothalamus, specifically pro-opiomelanocortin (POMC) neurons, controlling energy balance has not been established. Here, we aimed to determine the role of Sirt6 in hypothalamic POMC neurons in the regulation of energy balance and the underlying mechanisms. METHODS For overexpression studies, the hypothalamic arcuate nucleus (ARC) of diet-induced obese mice was targeted bilaterally and adenovirus was delivered by using stereotaxic apparatus. For knockout studies, the POMC neuron-specific Sirt6 knockout mice (PKO mice) were generated. Mice were fed with chow diet or high-fat diet, and body weight and food intake were monitored. Whole-body energy expenditure was determined by metabolic cages. Parameters of body composition and glucose/lipid metabolism were evaluated. RESULTS Sirt6 overexpression in the ARC ameliorated diet-induced obesity. Conversely, selective Sirt6 ablation in POMC neurons predisposed mice to obesity and metabolic disturbances. PKO mice showed an increased fat mass and food intake, while the energy expenditure was decreased. Mechanistically, Sirt6 could modulate leptin signaling in hypothalamic POMC neurons, with Sirt6 deficiency impairing leptin-induced phosphorylation of signal transducer and activator of transcription 3. The effects of leptin on reducing food intake and body weight and leptin-stimulated lipolysis were also impaired. Moreover, Sirt6 inhibition diminished the leptin-induced depolarization of POMC neurons. CONCLUSIONS Our results reveal a key role of Sirt6 in POMC neurons against energy imbalance, suggesting that Sirt6 is an important molecular regulator for POMC neurons to promote negative energy balance.
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Affiliation(s)
- Qin Tang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Yong Gao
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, China
| | - Qinhui Liu
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Xuping Yang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Tong Wu
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Cuiyuan Huang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Ya Huang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Jinhang Zhang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Zijing Zhang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Rui Li
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Shiyun Pu
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Guorong Zhang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Yingnan Zhao
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Jian Zhou
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Hui Huang
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Yanping Li
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Wei Jiang
- Molecular Medicine Research Center, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Yongsheng Chang
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin 300070, China.
| | - Jinhan He
- Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China.
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Yu H, Chhabra KH, Thompson Z, Jones GL, Kiran S, Shangguan G, Low MJ. Hypothalamic POMC deficiency increases circulating adiponectin despite obesity. Mol Metab 2020; 35:100957. [PMID: 32244188 PMCID: PMC7082555 DOI: 10.1016/j.molmet.2020.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/22/2020] [Accepted: 01/31/2020] [Indexed: 02/06/2023] Open
Abstract
Objective The steep rise in the prevalence of obesity and its related metabolic syndrome have become a major worldwide health concerns. Melanocortin peptides from hypothalamic arcuate nucleus (Arc) POMC neurons induce satiety to limit food intake. Consequently, Arc Pomc-deficient mice (ArcPomc−/−) exhibit hyperphagia and obesity. Previous studies demonstrated that the circulating levels of adiponectin, a protein abundantly produced and secreted by fat cells, negatively correlate with obesity in both rodents and humans. However, we found that ArcPomc−/− mice have increased circulating adiponectin levels despite obesity. Therefore, we investigated the physiological function and underlying mechanisms of hypothalamic POMC in regulating systemic adiponectin levels. Methods Circulating adiponectin was measured in obese ArcPomc−/− mice at ages 4–52 weeks. To determine whether increased adiponectin was a direct result of ArcPomc deficiency or a secondary effect of obesity, we examined plasma adiponectin levels in calorie-restricted mice with or without a history of obesity and in ArcPomc−/− mice before and after genetic restoration of Pomc expression in the hypothalamus. To delineate the mechanisms causing increased adiponectin in ArcPomc−/− mice, we determined sympathetic outflow to adipose tissue by assessing epinephrine, norepinephrine, and tyrosine hydroxylase protein levels and measured the circulating adiponectin in the mice after acute norepinephrine or propranolol treatments. In addition, adiponectin mRNA and protein levels were measured in discrete adipose tissue depots to ascertain which fat depots contributed the most to the high level of adiponectin in the ArcPomc−/− mice. Finally, we generated compound Adiopoq−/−:ArcPomc−/− mice and compared their growth, body composition, and glucose homeostasis to the individual knockout mouse strains and their wild-type controls. Results Obese ArcPomc−/− female mice had unexpectedly increased plasma adiponectin compared to wild-type siblings at all ages greater than 8 weeks. Despite chronic calorie restriction to achieve normal body weights, higher adiponectin levels persisted in the ArcPomc−/− female mice. Genetic restoration of Pomc expression in the Arc or acute treatment of the ArcPomc−/− female mice with melanotan II reduced adiponectin levels to control littermate values. The ArcPomc−/− mice had defective thermogenesis and decreased epinephrine, norepinephrine, and tyrosine hydroxylase protein levels in their fat pads, indicating reduced sympathetic outflow to adipose tissue. Injections of norepinephrine into the ArcPomc−/− female mice reduced circulating adiponectin levels, whereas injections of propranolol significantly increased adiponectin levels. Despite the beneficial effects of adiponectin on metabolism, the deletion of adiponectin alleles in the ArcPomc−/− mice did not exacerbate their metabolic abnormalities. Conclusion In summary, to the best of our knowledge, this study provides the first evidence that despite obesity, the ArcPomc−/− mouse model has high circulating adiponectin levels, which demonstrated that increased fat mass is not necessarily correlated with hypoadiponectinemia. Our investigation also found a previously unknown physiological pathway connecting POMC neurons via the sympathetic nervous system to circulating adiponectin, thereby shedding light on the biological regulation of adiponectin. Obese female hypothalamic-specific Pomc-deficient mice have unexpectedly elevated circulating adiponectin. Restoration of Pomc expression in the hypothalamus reduces plasma adiponectin. Low sympathetic output to subcutaneous fat depots in the Pomc-deficient mice contributes to high adiponectin levels. Deletion of adiponectin in hypothalamic-specific Pomc-deficient mice does not alter their metabolic phenotype.
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Affiliation(s)
- Hui Yu
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA.
| | - Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Zoe Thompson
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Graham L Jones
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Sylee Kiran
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; School of Literature, Science, and Arts, University of Michigan, Ann Arbor, MI, USA
| | - Gary Shangguan
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48105, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
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Guo S, Huang Y, Zhang Y, Huang H, Hong S, Liu T. Impacts of exercise interventions on different diseases and organ functions in mice. JOURNAL OF SPORT AND HEALTH SCIENCE 2020; 9:53-73. [PMID: 31921481 PMCID: PMC6943779 DOI: 10.1016/j.jshs.2019.07.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/09/2019] [Accepted: 04/29/2019] [Indexed: 05/20/2023]
Abstract
Background In recent years, much evidence has emerged to indicate that exercise can benefit people when performed properly. This review summarizes the exercise interventions used in studies involving mice as they are related to special diseases or physiological status. To further understand the effects of exercise interventions in treating or preventing diseases, it is important to establish a template for exercise interventions that can be used in future exercise-related studies. Methods PubMed was used as the data resource for articles. To identify studies related to the effectiveness of exercise interventions for treating various diseases and organ functions in mice, we used the following search language: (exercise [Title] OR training [Title] OR physical activity [Title]) AND (mice [title/abstract] OR mouse [title/abstract] OR mus [title/abstract]). To limit the range of search results, we included 2 filters: one that limited publication dates to "in 10 years" and one that sorted the results as "best match". Then we grouped the commonly used exercise methods according to their similarities and differences. We then evaluated the effectiveness of the exercise interventions for their impact on diseases and organ functions in 8 different systems. Results A total of 331 articles were included in the analysis procedure. The articles were then segmented into 8 systems for which the exercise interventions were used in targeting and treating disorders: motor system (60 studies), metabolic system (45 studies), cardio-cerebral vascular system (58 studies), nervous system (74 studies), immune system (32 studies), respiratory system (7 studies), digestive system (1 study), and the system related to the development of cancer (54 studies). The methods of exercise interventions mainly involved the use of treadmills, voluntary wheel-running, forced wheel-running, swimming, and resistance training. It was found that regardless of the specific exercise method used, most of them demonstrated positive effects on various systemic diseases and organ functions. Most diseases were remitted with exercise regardless of the exercise method used, although some diseases showed the best remission effects when a specific method was used. Conclusion Our review strongly suggests that exercise intervention is a cornerstone in disease prevention and treatment in mice. Because exercise interventions in humans typically focus on chronic diseases, national fitness, and body weight loss, and typically have low intervention compliance rates, it is important to use mice models to investigate the molecular mechanisms underlying the health benefits from exercise interventions in humans.
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Affiliation(s)
- Shanshan Guo
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Yiru Huang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China
| | - Yan Zhang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China
| | - He Huang
- Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, Changchun 130012, China
| | - Shangyu Hong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200032, China
| | - Tiemin Liu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
- Department of Endocrinology and Metabolism, State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
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25
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Cheng H, Gang X, He G, Liu Y, Wang Y, Zhao X, Wang G. The Molecular Mechanisms Underlying Mitochondria-Associated Endoplasmic Reticulum Membrane-Induced Insulin Resistance. Front Endocrinol (Lausanne) 2020; 11:592129. [PMID: 33329397 PMCID: PMC7719781 DOI: 10.3389/fendo.2020.592129] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Mitochondria and the endoplasmic reticulum (ER) are connected at multiple sites via what are known as mitochondria-associated ER membranes (MAMs). These associations are known to play an important role in maintaining cellular homeostasis. Impaired MAM signaling has wide-ranging effects in many diseases, such as obesity, diabetes, and neurodegenerative disorders. Accumulating evidence has suggested that MAMs influence insulin signaling through different pathways, including those associated with Ca2+ signaling, lipid metabolism, mitochondrial function, ER stress responses, and inflammation. Altered MAM signaling is a common feature of insulin resistance in different tissues, including the liver, muscle, and even the brain. In the liver, MAMs are key glucose-sensing regulators and have been proposed to be a hub for insulin signaling. Impaired MAM integrity has been reported to disrupt hepatic responses to changes in glucose availability during nutritional transition and to induce hepatic insulin resistance. Meanwhile, these effects can be rescued by the reinforcement of MAM interactions. In contrast, several studies have proposed that enhanced ER-mitochondria connections are detrimental to hepatic insulin signaling and can lead to mitochondrial dysfunction. Thus, given these contradictory results, the role played by the MAM in the regulation of hepatic insulin signaling remains elusive. Similarly, in skeletal muscle, enhanced MAM formation may be beneficial in the early stage of diabetes, whereas continuous MAM enhancement aggravates insulin resistance. Furthermore, recent studies have suggested that ER stress may be the primary pathway through which MAMs induce brain insulin resistance, especially in the hypothalamus. This review will discuss the possible mechanisms underlying MAM-associated insulin resistance as well as the therapeutic potential of targeting the MAM in the treatment of type 2 diabetes.
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Affiliation(s)
| | | | | | | | | | - Xue Zhao
- *Correspondence: Guixia Wang, ; Xue Zhao,
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26
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Bhattacharya A, Qi L. ER-associated degradation in health and disease - from substrate to organism. J Cell Sci 2019; 132:132/23/jcs232850. [PMID: 31792042 DOI: 10.1242/jcs.232850] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The recent literature has revolutionized our view on the vital importance of endoplasmic reticulum (ER)-associated degradation (ERAD) in health and disease. Suppressor/enhancer of Lin-12-like (Sel1L)-HMG-coA reductase degradation protein 1 (Hrd1)-mediated ERAD has emerged as a crucial determinant of normal physiology and as a sentinel against disease pathogenesis in the body, in a largely substrate- and cell type-specific manner. In this Review, we highlight three features of ERAD, constitutive versus inducible ERAD, quality versus quantity control of ERAD and ERAD-mediated regulation of nuclear gene transcription, through which ERAD exerts a profound impact on a number of physiological processes.
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Affiliation(s)
- Asmita Bhattacharya
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105, USA.,Graduate Program of Genetics, Genomics and Development, Cornell University, Ithaca, NY 14853, USA
| | - Ling Qi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105, USA .,Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48105, USA
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27
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Huang S, Xing Y, Liu Y. Emerging roles for the ER stress sensor IRE1α in metabolic regulation and disease. J Biol Chem 2019; 294:18726-18741. [PMID: 31666338 DOI: 10.1074/jbc.rev119.007036] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Inositol-requiring enzyme 1 (IRE1) is an endoplasmic reticulum (ER)-resident transmembrane protein that senses ER stress and is evolutionarily conserved from yeast to humans. IRE1 possesses both Ser/Thr protein kinase and endoribonuclease (RNase) activities within its cytoplasmic domain and is activated through autophosphorylation and dimerization/oligomerization. It mediates a critical arm of the unfolded protein response to manage ER stress provoked by lumenal overload of unfolded/misfolded proteins. Emerging lines of evidence have revealed that in mammals, IRE1α functions as a multifunctional signal transducer that responds to metabolic cues and nutrient stress conditions, exerting profound and broad effects on metabolic homeostasis. In this review, we cover recent advances in our understanding of how IRE1α integrates a variety of metabolic and stress signals and highlight its tissue-specific or context-dependent metabolic activities. We also discuss how dysregulation of this metabolic stress sensor during handling of excessive nutrients in cells contributes to the progression of obesity and metabolic disorders.
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Affiliation(s)
- Shijia Huang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yuying Xing
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yong Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
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28
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He Z, Gao Y, Lieu L, Afrin S, Cao J, Michael NJ, Dong Y, Sun J, Guo H, Williams KW. Direct and indirect effects of liraglutide on hypothalamic POMC and NPY/AgRP neurons - Implications for energy balance and glucose control. Mol Metab 2019; 28:120-134. [PMID: 31446151 PMCID: PMC6822260 DOI: 10.1016/j.molmet.2019.07.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 07/22/2019] [Accepted: 07/25/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE The long-acting glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, stimulates insulin secretion and efficiently suppresses food intake to reduce body weight. As such, liraglutide is growing in popularity in the treatment of diabetes and chronic weight management. Within the brain, liraglutide has been shown to alter the activity of hypothalamic proopiomelanocortin (POMC) and Neuropeptide Y/Agouti-related peptide (NPY/AgRP) neurons. Moreover, the acute activities of POMC and NPY neurons have been directly linked to feeding behavior, body weight, and glucose metabolism. Despite the increased usage of liraglutide and other GLP-1 analogues as diabetic and obesity interventions, the cellular mechanisms by which liraglutide alters the activity of metabolically relevant neuronal populations are poorly understood. METHODS In order to resolve this issue, we utilized neuron-specific transgenic mouse models to identify POMC and NPY neurons for patch-clamp electrophysiology experiments. RESULTS We found that liraglutide directly activated arcuate POMC neurons via TrpC5 channels, sharing a similar mechanistic pathway to the adipose-derived peptide leptin. Liraglutide also indirectly increases excitatory tone to POMC neurons. In contrast, liraglutide inhibited NPY/AgRP neurons through post-synaptic GABAA receptors and enhanced activity of pre-synaptic GABAergic neurons, which required both TrpC5 subunits and K-ATP channels. In support of an additive role of leptin and liraglutide in suppressing food intake, leptin potentiated the acute effects of liraglutide to activate POMC neurons. TrpC5 subunits in POMC neurons were also required for the intact pharmacological effects of liraglutide on food intake and body weight. Thus, the current study adds to recent work from our group and others, which highlight potential mechanisms to amplify the effects of GLP-1 agonists in vivo. Moreover, these data highlight multiple sites of action (both pre- and post-synaptic) for GLP-1 agonists on this circuit. CONCLUSIONS Taken together, our results identify critical molecular mechanisms linking GLP-1 analogues in arcuate POMC and NPY/AgRP neurons with metabolism.
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Affiliation(s)
- Zhenyan He
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yong Gao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Linh Lieu
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Sadia Afrin
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Jianhong Cao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Natalie J Michael
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yanbin Dong
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Jia Sun
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Hongbo Guo
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Kevin W Williams
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA.
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29
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Abstract
In the midst of an obesity epidemic, the promotion of brown adipose tissue (BAT) function and the browning of white adipose tissue (WAT) have emerged as promising therapeutic targets to increase energy expenditure and counteract weight gain. Despite the fact that the thermogenic potential of bone fide BAT in rodents is several orders of magnitudes higher than white fat containing brite/beige adipocytes, WAT browning represents a particularly intriguing concept in humans given the extreme amount of excess WAT in obese individuals. In addition, the clear distinction between classic brown and beige fat that has been proposed in mice does not exist in humans. In fact, studies of human BAT biopsies found controversial results suggesting both classic brown and beige characteristics. Irrespective of the true ‘color’, accumulating evidence suggests the induction of thermogenic adipocytes in human WAT depots in response to specific stimuli, highlighting that WAT browning may occur in both, mice and humans. These observations also emphasize the great plasticity of human fat depots and raise important questions about the metabolic properties of thermogenically active adipose tissue in humans and the potential therapeutic implications. We will first review the cellular and molecular aspects of selected adipose tissue browning concepts that have been identified in mouse models with emphasis on neuronal factors, the microbiome, immune cells and several hormones. We will also summarize the evidence for adipose tissue browning in humans including some experimental pharmacologic approaches.
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Affiliation(s)
- Carsten T Herz
- Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Florian W Kiefer
- Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
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30
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Ratner C, He Z, Grunddal KV, Skov LJ, Hartmann B, Zhang F, Feuchtinger A, Bjerregaard A, Christoffersen C, Tschöp MH, Finan B, DiMarchi RD, Leinninger GM, Williams KW, Clemmensen C, Holst B. Long-Acting Neurotensin Synergizes With Liraglutide to Reverse Obesity Through a Melanocortin-Dependent Pathway. Diabetes 2019; 68:1329-1340. [PMID: 30936142 PMCID: PMC6610020 DOI: 10.2337/db18-1009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 03/18/2019] [Indexed: 02/07/2023]
Abstract
Neurotensin (NT), a gut hormone and neuropeptide, increases in circulation after bariatric surgery in rodents and humans and inhibits food intake in mice. However, its potential to treat obesity and the subsequent metabolic dysfunctions have been difficult to assess owing to its short half-life in vivo. Here, we demonstrate that a long-acting, pegylated analog of the NT peptide (P-NT) reduces food intake, body weight, and adiposity in diet-induced obese mice when administered once daily for 6 days. Strikingly, when P-NT was combined with the glucagon-like peptide 1 mimetic liraglutide, the two peptides synergized to reduce food intake and body weight relative to each monotherapy, without inducing a taste aversion. Further, P-NT and liraglutide coadministration improved glycemia and reduced steatohepatitis. Finally, we show that the melanocortin pathway is central for P-NT-induced anorexia and necessary for the full synergistic effect of P-NT and liraglutide combination therapy. Overall, our data suggest that P-NT and liraglutide combination therapy could be an enhanced treatment for obesity with improved tolerability compared with liraglutide monotherapy.
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Affiliation(s)
- Cecilia Ratner
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zhenyan He
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX
| | - Kaare V Grunddal
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise J Skov
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Fa Zhang
- Department of Chemistry, Indiana University, Bloomington, IN
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Munich, Germany
| | - Anette Bjerregaard
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Christoffersen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, Munich, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Brian Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN
| | | | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Kevin W Williams
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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31
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Cakir I, Nillni EA. Endoplasmic Reticulum Stress, the Hypothalamus, and Energy Balance. Trends Endocrinol Metab 2019; 30:163-176. [PMID: 30691778 DOI: 10.1016/j.tem.2019.01.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/17/2018] [Accepted: 01/03/2019] [Indexed: 01/09/2023]
Abstract
Overweight and obesity pose significant health problems globally, and are causatively linked to metabolic dysregulation. The hypothalamus integrates neural, nutritional, and hormonal cues to regulate homeostasis, including circadian rhythm, body temperature, thirst, food intake, energy expenditure, and glucose metabolism. Hypothalamic neuropeptides play a fundamental role in these processes. Studies during the past two decades suggest a role of central endoplasmic reticulum (ER) stress in the pathophysiology of obesity. This review covers recent findings on the role of ER stress and neuropeptide processing in the central regulation of energy homeostasis, with special emphasis on proopiomelanocortin (POMC)-encoding neurons. In addition, the role of neuroinflammation in the context of obesity is briefly discussed.
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Affiliation(s)
- Isin Cakir
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Eduardo A Nillni
- Department of Medicine, Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.
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32
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Martínez G, Khatiwada S, Costa-Mattioli M, Hetz C. ER Proteostasis Control of Neuronal Physiology and Synaptic Function. Trends Neurosci 2018; 41:610-624. [PMID: 29945734 PMCID: PMC7268632 DOI: 10.1016/j.tins.2018.05.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/08/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022]
Abstract
Neuronal proteostasis is maintained by the dynamic integration of different processes that regulate the synthesis, folding, quality control, and localization of proteins. The endoplasmic reticulum (ER) serves as a fundamental pillar of the proteostasis network, and is emerging as a key compartment to sustain normal brain function. The unfolded protein response (UPR), the main mechanism that copes with ER stress, plays a central role in the quality control of many ion channels and receptors, in addition to crosstalk with signaling pathways that regulate connectivity, synapse formation, and neuronal plasticity. We provide here an overview of recent advances in the involvement of the UPR in maintaining neuronal proteostasis, and discuss its emerging role in brain development, neuronal physiology, and behavior, as well as the implications for neurodegenerative diseases involving cognitive decline.
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Affiliation(s)
- Gabriela Martínez
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile
| | - Sanjeev Khatiwada
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA 94945, USA; Department of Immunology and Infectious diseases, Harvard School of Public Health, Boston, MA 02115, USA.
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33
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Alvarsson A, Stanley SA. Remote control of glucose-sensing neurons to analyze glucose metabolism. Am J Physiol Endocrinol Metab 2018; 315:E327-E339. [PMID: 29812985 PMCID: PMC6171010 DOI: 10.1152/ajpendo.00469.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 12/13/2022]
Abstract
The central nervous system relies on a continual supply of glucose, and must be able to detect glucose levels and regulate peripheral organ functions to ensure that its energy requirements are met. Specialized glucose-sensing neurons, first described half a century ago, use glucose as a signal and modulate their firing rates as glucose levels change. Glucose-excited neurons are activated by increasing glucose concentrations, while glucose-inhibited neurons increase their firing rate as glucose concentrations fall and decrease their firing rate as glucose concentrations rise. Glucose-sensing neurons are present in multiple brain regions and are highly expressed in hypothalamic regions, where they are involved in functions related to glucose homeostasis. However, the roles of glucose-sensing neurons in healthy and disease states remain poorly understood. Technologies that can rapidly and reversibly activate or inhibit defined neural populations provide invaluable tools to investigate how specific neural populations regulate metabolism and other physiological roles. Optogenetics has high temporal and spatial resolutions, requires implants for neural stimulation, and is suitable for modulating local neural populations. Chemogenetics, which requires injection of a synthetic ligand, can target both local and widespread populations. Radio- and magnetogenetics offer rapid neural activation in localized or widespread neural populations without the need for implants or injections. These tools will allow us to better understand glucose-sensing neurons and their metabolism-regulating circuits.
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Affiliation(s)
- Alexandra Alvarsson
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
| | - Sarah A Stanley
- Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai , New York, New York
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, New York
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34
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Endoplasmic Reticulum Stress in Metabolic Disorders. Cells 2018; 7:cells7060063. [PMID: 29921793 PMCID: PMC6025008 DOI: 10.3390/cells7060063] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 02/06/2023] Open
Abstract
Metabolic disorders have become among the most serious threats to human health, leading to severe chronic diseases such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, as well as cardiovascular diseases. Interestingly, despite the fact that each of these diseases has different physiological and clinical symptoms, they appear to share certain pathological traits such as intracellular stress and inflammation induced by metabolic disturbance stemmed from over nutrition frequently aggravated by a modern, sedentary life style. These modern ways of living inundate cells and organs with saturating levels of sugar and fat, leading to glycotoxicity and lipotoxicity that induce intracellular stress signaling ranging from oxidative to ER stress response to cope with the metabolic insults (Mukherjee, et al., 2015). In this review, we discuss the roles played by cellular stress and its responses in shaping metabolic disorders. We have summarized here current mechanistic insights explaining the pathogenesis of these disorders. These are followed by a discussion of the latest therapies targeting the stress response pathways.
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35
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Ye Z, Liu G, Guo J, Su Z. Hypothalamic endoplasmic reticulum stress as a key mediator of obesity-induced leptin resistance. Obes Rev 2018. [PMID: 29514392 DOI: 10.1111/obr.12673] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obesity is an epidemic disease that is increasing worldwide and is a major risk factor for many metabolic diseases. However, effective agents for the prevention or treatment of obesity remain limited. Therefore, it is urgent to clarify the pathophysiological mechanisms underlying the development and progression of obesity and exploit potential agents to cure and prevent this disease. According to a recent study series, obesity is associated with the development of endoplasmic reticulum stress and the activation of its stress responses (unfolded protein response) in metabolically active tissues, which contribute to the development of obesity-related insulin and leptin resistance, inflammation and energy imbalance. Hypothalamic endoplasmic reticulum stress is the central mechanism underlying the development of obesity-associated leptin resistance and disruption of energy homeostasis; thus, targeting endoplasmic reticulum stress offers a promising therapeutic strategy for improving leptin sensitivity, increasing energy expenditure and ultimately combating obesity. In this review, we highlight the relationship between and mechanism underlying hypothalamic endoplasmic reticulum stress and obesity-associated leptin resistance and energy imbalance and provide new insight regarding strategies for the treatment of obesity.
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Affiliation(s)
- Z Ye
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Pharmaceutical University, Guangzhou, China
| | - G Liu
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - J Guo
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China
| | - Z Su
- Guangdong Metabolic Disease Research Center of Integrated Chinese and Western Medicine, Key Unit of Modulating Liver to Treat Hyperlipemia SATCM (State Administration of Traditional Chinese Medicine), Guangdong Pharmaceutical University, Guangzhou, China.,Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Pharmaceutical University, Guangzhou, China
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36
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Kim GH, Shi G, Somlo DR, Haataja L, Song S, Long Q, Nillni EA, Low MJ, Arvan P, Myers MG, Qi L. Hypothalamic ER-associated degradation regulates POMC maturation, feeding, and age-associated obesity. J Clin Invest 2018; 128:1125-1140. [PMID: 29457782 PMCID: PMC5824855 DOI: 10.1172/jci96420] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/14/2017] [Indexed: 12/18/2022] Open
Abstract
Pro-opiomelanocortin (POMC) neurons function as key regulators of metabolism and physiology by releasing prohormone-derived neuropeptides with distinct biological activities. However, our understanding of early events in prohormone maturation in the ER remains incomplete. Highlighting the significance of this gap in knowledge, a single POMC cysteine-to-phenylalanine mutation at position 28 (POMC-C28F) is defective for ER processing and causes early onset obesity in a dominant-negative manner in humans through an unclear mechanism. Here, we report a pathologically important role of Sel1L-Hrd1, the protein complex of ER-associated degradation (ERAD), within POMC neurons. Mice with POMC neuron–specific Sel1L deficiency developed age-associated obesity due, at least in part, to the ER retention of POMC that led to hyperphagia. The Sel1L-Hrd1 complex targets a fraction of nascent POMC molecules for ubiquitination and proteasomal degradation, preventing accumulation of misfolded and aggregated POMC, thereby ensuring that another fraction of POMC can undergo normal posttranslational processing and trafficking for secretion. Moreover, we found that the disease-associated POMC-C28F mutant evades ERAD and becomes aggregated due to the presence of a highly reactive unpaired cysteine thiol at position 50. Thus, this study not only identifies ERAD as an important mechanism regulating POMC maturation within the ER, but also provides insights into the pathogenesis of monogenic obesity associated with defective prohormone folding.
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Affiliation(s)
- Geun Hyang Kim
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Guojun Shi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Diane Rm Somlo
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, USA
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Soobin Song
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, USA
| | - Qiaoming Long
- Cam-Su Genomic Resource Center, Soochow University, Suzhou, Jiangsu, China
| | - Eduardo A Nillni
- The Warren Alpert Medical School, Department of Medicine, Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Malcolm J Low
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Peter Arvan
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Martin G Myers
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ling Qi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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37
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Melanocortin neurons: Multiple routes to regulation of metabolism. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2477-2485. [PMID: 28499988 DOI: 10.1016/j.bbadis.2017.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/31/2017] [Accepted: 05/05/2017] [Indexed: 01/07/2023]
Abstract
The burden of disability, premature death, escalating health care costs and lost economic productivity due to obesity and its associated complications including hypertension, stroke, cardiovascular disease and type 2 diabetes is staggering [1,2]. A better understanding of metabolic homeostatic pathways will provide us with insights into the biological mechanisms of obesity and how to fundamentally address this epidemic [3-6]. In mammals, energy balance is maintained via a homeostatic system involving both peripheral and central melanocortin systems; changes in body weight reflect an unbalance of the energetic state [7-9]. Although the primary cause of obesity is unknown, there is significant effort to understand the role of the central melanocortin pathway in the brain as it has been shown that deficiency of proopiomelanocortin (POMC) [10,11] and melanocortin 4 receptors (MC4R) [12-15] in both rodents and humans results in severe hyperphagia and obesity [16-23]. In this review, we will summarize how the central melanocortin pathway helps regulate body mass and adiposity within a 'healthy' range through the 'nutrient sensing' network [24-28]. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Chandrahas VK, Han J, Kaufman RJ. Coordinating Organismal Metabolism During Protein Misfolding in the ER Through the Unfolded Protein Response. Curr Top Microbiol Immunol 2017; 414:103-130. [PMID: 28900680 DOI: 10.1007/82_2017_41] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The endoplasmic reticulum (ER) is a cellular organelle responsible for folding of secretory and membrane proteins. Perturbance in ER homeostasis caused by various intrinsic/extrinsic stimuli challenges the protein-folding capacity of the ER, leading to an ER dysfunction, called ER stress. Cells have developed a defensive response to adapt and/or survive in the face of ER stress that may be detrimental to cell function and survival. When exposed to ER stress, the cell activates a complex and elaborate signaling network that includes translational modulation and transcriptional induction of genes. In addition to these autonomous responses, recent studies suggest that the stressed tissue secretes peptides or unknown factors that transfer the signal to other cells in the same or different organs, leading the organism as a whole to cope with challenges in a non-autonomous manner. In this review, we discuss the mechanisms by which cells adapt to ER stress challenges autonomously and transfer the stress signal to non-stressed cells in different organs.
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Affiliation(s)
- Vishwanatha K Chandrahas
- Degenerative Diseases Program, Sanford_Burnham_Prebys Medical Discovery Institute, 92037, La Jolla, CA, USA
| | - Jaeseok Han
- Soonchunhyang Institute of Med-bio Science (SIMS), Soonchunhyang University, 31151, Cheonan-si, Chungcheongnam-do, Republic of Korea.
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford_Burnham_Prebys Medical Discovery Institute, 92037, La Jolla, CA, USA.
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