1
|
Fernández-Veledo S, Marsal-Beltran A, Vendrell J. Type 2 diabetes and succinate: unmasking an age-old molecule. Diabetologia 2024; 67:430-442. [PMID: 38182909 PMCID: PMC10844351 DOI: 10.1007/s00125-023-06063-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/18/2023] [Indexed: 01/07/2024]
Abstract
Beyond their conventional roles in intracellular energy production, some traditional metabolites also function as extracellular messengers that activate cell-surface G-protein-coupled receptors (GPCRs) akin to hormones and neurotransmitters. These signalling metabolites, often derived from nutrients, the gut microbiota or the host's intermediary metabolism, are now acknowledged as key regulators of various metabolic and immune responses. This review delves into the multi-dimensional aspects of succinate, a dual metabolite with roots in both the mitochondria and microbiome. It also connects the dots between succinate's role in the Krebs cycle, mitochondrial respiration, and its double-edge function as a signalling transmitter within and outside the cell. We aim to provide an overview of the role of the succinate-succinate receptor 1 (SUCNR1) axis in diabetes, discussing the potential use of succinate as a biomarker and the novel prospect of targeting SUCNR1 to manage complications associated with diabetes. We further propose strategies to manipulate the succinate-SUCNR1 axis for better diabetes management; this includes pharmacological modulation of SUCNR1 and innovative approaches to manage succinate concentrations, such as succinate administration and indirect strategies, like microbiota modulation. The dual nature of succinate, both in terms of origins and roles, offers a rich landscape for understanding the intricate connections within metabolic diseases, like diabetes, and indicates promising pathways for developing new therapeutic strategies.
Collapse
Affiliation(s)
- Sonia Fernández-Veledo
- Hospital Universitari Joan XXIII de Tarragona, Institut d'Investigació Sanitària Pere Virgili (IISPV)-CERCA, Tarragona, Spain.
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III (ISCIII), Madrid, Spain.
- Universitat Rovira I Virgili (URV), Reus, Spain.
| | - Anna Marsal-Beltran
- Hospital Universitari Joan XXIII de Tarragona, Institut d'Investigació Sanitària Pere Virgili (IISPV)-CERCA, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Universitat Rovira I Virgili (URV), Reus, Spain
| | - Joan Vendrell
- Hospital Universitari Joan XXIII de Tarragona, Institut d'Investigació Sanitària Pere Virgili (IISPV)-CERCA, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Universitat Rovira I Virgili (URV), Reus, Spain
| |
Collapse
|
2
|
Goetzman E, Gong Z, Zhang B, Muzumdar R. Complex II Biology in Aging, Health, and Disease. Antioxidants (Basel) 2023; 12:1477. [PMID: 37508015 PMCID: PMC10376733 DOI: 10.3390/antiox12071477] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/11/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Aging is associated with a decline in mitochondrial function which may contribute to age-related diseases such as neurodegeneration, cancer, and cardiovascular diseases. Recently, mitochondrial Complex II has emerged as an important player in the aging process. Mitochondrial Complex II converts succinate to fumarate and plays an essential role in both the tricarboxylic acid (TCA) cycle and the electron transport chain (ETC). The dysfunction of Complex II not only limits mitochondrial energy production; it may also promote oxidative stress, contributing, over time, to cellular damage, aging, and disease. Intriguingly, succinate, the substrate for Complex II which accumulates during mitochondrial dysfunction, has been shown to have widespread effects as a signaling molecule. Here, we review recent advances related to understanding the function of Complex II, succinate signaling, and their combined roles in aging and aging-related diseases.
Collapse
Affiliation(s)
- Eric Goetzman
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Zhenwei Gong
- Division of Endocrinology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Bob Zhang
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Radhika Muzumdar
- Division of Endocrinology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| |
Collapse
|
3
|
The Succinate Receptor SUCNR1 Resides at the Endoplasmic Reticulum and Relocates to the Plasma Membrane in Hypoxic Conditions. Cells 2022; 11:cells11142185. [PMID: 35883628 PMCID: PMC9321536 DOI: 10.3390/cells11142185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 12/24/2022] Open
Abstract
The GPCR SUCNR1/GPR91 exerts proangiogenesis upon stimulation with the Krebs cycle metabolite succinate. GPCR signaling depends on the surrounding environment and intracellular localization through location bias. Here, we show by microscopy and by cell fractionation that in neurons, SUCNR1 resides at the endoplasmic reticulum (ER), while being fully functional, as shown by calcium release and the induction of the expression of the proangiogenic gene for VEGFA. ER localization was found to depend upon N-glycosylation, particularly at position N8; the nonglycosylated mutant receptor localizes at the plasma membrane shuttled by RAB11. This SUCNR1 glycosylation is physiologically regulated, so that during hypoxic conditions, SUCNR1 is deglycosylated and relocates to the plasma membrane. Downstream signal transduction of SUCNR1 was found to activate the prostaglandin synthesis pathway through direct interaction with COX-2 at the ER; pharmacologic antagonism of the PGE2 EP4 receptor (localized at the nucleus) was found to prevent VEGFA expression. Concordantly, restoring the expression of SUCNR1 in the retina of SUCNR1-null mice renormalized vascularization; this effect is markedly diminished after transfection of the plasma membrane-localized SUCNR1 N8A mutant, emphasizing that ER localization of the succinate receptor is necessary for proper vascularization. These findings uncover an unprecedented physiologic process where GPCR resides at the ER for signaling function.
Collapse
|
4
|
Bisbach CM, Hass DT, Thomas ED, Cherry TJ, Hurley JB. Monocarboxylate Transporter 1 (MCT1) Mediates Succinate Export in the Retina. Invest Ophthalmol Vis Sci 2022; 63:1. [PMID: 35363247 PMCID: PMC8976921 DOI: 10.1167/iovs.63.4.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Succinate is exported by the retina and imported by eyecup tissue. The transporters mediating this process have not yet been identified. Recent studies showed that monocarboxylate transporter 1 (MCT1) can transport succinate across plasma membranes in cardiac and skeletal muscle. Retina and retinal pigment epithelium (RPE) both express multiple MCT isoforms including MCT1. We tested the hypothesis that MCTs facilitate retinal succinate export and RPE succinate import. Methods We assessed retinal succinate export and eyecup succinate import in short-term ex vivo culture using gas chromatography–mass spectrometry. We tested the dependence of succinate export and import on pH, proton ionophores, conventional MCT substrates, and the MCT inhibitors AZD3965, AR-C155858, and diclofenac. Results Succinate exits retinal tissue through MCT1 but does not enter the RPE through MCT1 or any other MCT. Intracellular succinate levels are a contributing factor that determines if an MCT1-expressing tissue will export succinate. Conclusions MCT1 facilitates export of succinate from retinas. An unidentified, non-MCT transporter facilitates import of succinate into RPE.
Collapse
Affiliation(s)
- Celia M Bisbach
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Daniel T Hass
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Eric D Thomas
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Timothy J Cherry
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, United States
| | - James B Hurley
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| |
Collapse
|
5
|
Foresight regarding drug candidates acting on the succinate-GPR91 signalling pathway for non-alcoholic steatohepatitis (NASH) treatment. Biomed Pharmacother 2021; 144:112298. [PMID: 34649219 DOI: 10.1016/j.biopha.2021.112298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and it is a liver manifestation of metabolic syndrome, with a histological spectrum from simple steatosis to non-alcoholic steatohepatitis (NASH). NASH can evolve into progressive liver fibrosis and eventually lead to liver cirrhosis. The pathological mechanism of NASH is multifactorial, involving a series of metabolic disorders and changes that trigger low-level inflammation in the liver and other organs. In the pathogenesis of NASH, the signal transduction pathway involving succinate and the succinate receptor (G-protein-coupled receptor 91, GPR91) regulates inflammatory cell activation and liver fibrosis. This review describes the mechanism of the succinate-GPR91 signalling pathway in NASH and summarizes the drugs that act on this pathway, with the aim of providing a new approach to NASH treatment.
Collapse
|
6
|
Fernández-Veledo S, Ceperuelo-Mallafré V, Vendrell J. Rethinking succinate: an unexpected hormone-like metabolite in energy homeostasis. Trends Endocrinol Metab 2021; 32:680-692. [PMID: 34301438 DOI: 10.1016/j.tem.2021.06.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 02/07/2023]
Abstract
There has been an explosion of interest in the signaling capacity of energy metabolites. A prime example is the Krebs cycle substrate succinate, an archetypal respiratory substrate with functions beyond energy production as an intracellular and extracellular signaling molecule. Long associated with inflammation, emerging evidence supports a key role for succinate in metabolic processes relating to energy management. As the natural ligand for SUCNR1, a G protein-coupled receptor, succinate is akin to hormones and likely functions as a reporter of metabolism and stress. In this review, we reconcile new and old observations to outline a regulatory role for succinate in metabolic homeostasis. We highlight the importance of the succinate-SUCNR1 axis in metabolic diseases as an integrator of macrophage immune response, and we discuss new metabolic functions recently ascribed to succinate in specific tissues. Because circulating succinate has emerged as a promising biomarker in chronic metabolic diseases, a better understanding of the physiopathological role of the succinate-SUCNR1 axis in metabolism might open new avenues for clinical use in patients with obesity or diabetes.
Collapse
Affiliation(s)
- Sonia Fernández-Veledo
- Department of Endocrinology and Nutrition and Research Unit, University Hospital of Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain.
| | - Victòria Ceperuelo-Mallafré
- Department of Endocrinology and Nutrition and Research Unit, University Hospital of Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain; Department of Medicine and Surgery, University Rovira I Virgili, Tarragona, Spain
| | - Joan Vendrell
- Department of Endocrinology and Nutrition and Research Unit, University Hospital of Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain; Department of Medicine and Surgery, University Rovira I Virgili, Tarragona, Spain
| |
Collapse
|
7
|
Succinate Receptor 1: An Emerging Regulator of Myeloid Cell Function in Inflammation. Trends Immunol 2020; 42:45-58. [PMID: 33279412 DOI: 10.1016/j.it.2020.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022]
Abstract
The rapidly evolving area of immunometabolism has shed new light on the fundamental properties of products and intermediates of cellular metabolism (metabolites), highlighting their key signaling roles in cell-to-cell communication. Recent evidence identifies the succinate-succinate receptor 1 (SUCNR1) axis as an essential regulator of tissue homeostasis. Succinate signaling via SUCNR1 guides divergent responses in immune cells, which are tissue and context dependent. Herein, we explore the main cellular pathways regulated by the succinate-SUCNR1 axis and focus on the biology of SUCNR1 and its roles influencing the function of myeloid cells. Hence, we identify new therapeutic targets and putative therapeutic approaches aimed at resolving detrimental myeloid cell responses in tissues, including those occurring in the persistently inflamed central nervous system (CNS).
Collapse
|
8
|
Li X, Xie L, Qu X, Zhao B, Fu W, Wu B, Wu J. GPR91, a critical signaling mechanism in modulating pathophysiologic processes in chronic illnesses. FASEB J 2020; 34:13091-13105. [PMID: 32812686 DOI: 10.1096/fj.202001037r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/08/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022]
Abstract
Succinate receptor GPR91 is one of G protein-coupled receptors (GPCRs), and is expressed in a variety of cell types and tissues. Succinate is its natural ligand, and its activation represents that an intrinsic metabolic intermediate exerts a regulatory role on many critical life processes involving pathophysiologic mechanisms, such as innate immunity, inflammation, tissue repair, and oncogenesis. With the illustration of 3-dimensional crystal structure of the receptor and discovery of its antagonists, it is possible to dissect the succinate-GPR91-G protein signaling pathways in different cell types under pathophysiological conditions. Deep understanding of the GPR91-ligand binding mode with various agonists and antagonists would aid in elucidating the molecular basis of a spectrum of chronic illnesses, such as hypertension, diabetes, and their renal and retina complications, metabolic-associated fatty liver diseases, such as nonalcoholic steatohepatitis and its fibrotic progression, inflammatory bowel diseases (Crohn's disease and ulcerative colitis), age-related macular degeneration, rheumatoid arthritis, and progressive behaviors of malignancies. With better delineation of critical regulatory role of the succinate-GPR91 axis in these illnesses, therapeutic intervention may be developed by specifically targeting this signaling pathway with small molecular antagonists or other strategies.
Collapse
Affiliation(s)
- Xinyi Li
- Department of Medical Microbiology, MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Li Xie
- Department of Medical Microbiology, MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Xiangli Qu
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bangyi Zhao
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai, China
| | - Wei Fu
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai, China
| | - Beili Wu
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jian Wu
- Department of Medical Microbiology, MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Department of Gastroenterology & Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Liver Diseases, Fudan University Shanghai Medical College, Shanghai, China
| |
Collapse
|
9
|
Louer EMM, Lorés-Motta L, Ion AM, Den Hollander AI, Deen PMT. Single nucleotide polymorphism rs13079080 is associated with differential regulation of the succinate receptor 1 (SUCNR1) gene by miRNA-4470. RNA Biol 2019; 16:1547-1554. [PMID: 31304868 PMCID: PMC6779389 DOI: 10.1080/15476286.2019.1643100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Oxidative stress is a feature of many common diseases. It leads to excessive formation and subsequent release of the mitochondrial metabolite succinate, which acts as a signalling molecule through binding the succinate receptor (SUCNR1). Recently, a potential role for SUCNR1 was proposed in age-related macular degeneration (AMD), a common cause of vision loss in the elderly associated with increased oxidative stress. Here, we evaluated the potential effect of genetic variants in SUCNR1 on its expression through differential micro-RNA (miRNA) binding to target mRNA, and investigated the relevance of altered SUCNR1 expression in AMD pathogenesis. We analysed common SUCNR1 SNPs for potential miRNA binding sites and identified rs13079080, located in the 3'-UTR and binding site for miRNA-4470. Both miRNA-4470 and SUCNR1 were found to be expressed in human retina. Moreover, using a luciferase reporter assay, a 60% decrease in activity was observed when miRNA-4470 was co-expressed with the C allele compared to the T allele of rs13079080. Finally, genotyping rs13079080 in an AMD case-control cohort revealed a protective effect of the TT genotype on AMD compared to the CC genotype (p = 0.007, odds ratio = 0.66). However, the association was not confirmed in the case-control study of the International AMD Genomics Consortium. Our study demonstrates that the T allele of rs13079080 in SUCNR1 disrupts a binding site for miRNA-4470, potentially increasing SUCNR1 expression and consequently increasing the capacity of sensing and dealing with oxidative stress. Therefore, it would be worthwhile assessing the relevance of rs13079080 in other oxidative stress-associated diseases in future studies.
Collapse
Affiliation(s)
- Elja M M Louer
- Dept of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands.,Dept of Ophthalmology, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Laura Lorés-Motta
- Dept of Ophthalmology, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Ana Mãdãlina Ion
- Dept of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands.,Dept of Ophthalmology, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Anneke I Den Hollander
- Dept of Ophthalmology, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center , Nijmegen , The Netherlands.,Dept of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Peter M T Deen
- Dept of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands
| |
Collapse
|
10
|
Gao Y, Qian H, Tang X, Du X, Wang G, Zhang H, Ye F, Liu T. Superparamagnetic iron oxide nanoparticle-mediated expression of miR-326 inhibits human endometrial carcinoma stem cell growth. Int J Nanomedicine 2019; 14:2719-2731. [PMID: 31114192 PMCID: PMC6497851 DOI: 10.2147/ijn.s200480] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 03/20/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Previously, our group confirmed the presence of a subset of cancer stem cells in the tissues of endometrial carcinoma (ie, human endometrial carcinoma stem cells [HuECSCs]). However, the mechanisms by which microRNAs regulate the growth of HuECSCs remain elusive. Methods: We loaded miR-326 onto superparamagnetic iron oxide nanoparticles (miR-326@SPION) and transfected them into HuECSCs. Results: In the present study, we found that the expression levels of members of the G-protein coupled receptor 91 (GPR91)/signal transducer and activator of transcription 3 (STAT3)/vascular endothelial growth factor (VEGF) pathway were significantly elevated in CD44+/CD133+ HuECSCs. Luciferase reporter assays indicated that the succinate receptor 1 (SUCNR1) gene, also known as the G-protein coupled receptor 91 (GPR91) gene, was one of the potential targets of miR-326. Transmission electron microscopy revealed that the SPIONs could cross the cell membrane and accumulate in the cytoplasm. The overexpression of miR-326 significantly inhibited the proliferation and cell cycle progression of HuECSCs in vitro. MiR-326 overexpression also effectively inhibited the invasion and angiogenic capacities of HuECSCs in the extracellular matrix. Meanwhile, miR-326 overexpression significantly inhibited the tumorigenicity and tumour neovascularization capacity of HuECSCs in nude mice. Both quantitative real-time PCR and Western blotting confirmed that overexpression of miR-326 significantly reduced the expression of members of the GPR91/STAT3/VEGF pathway in HuECSCs, and the activity (level of phosphorylation) of key molecules in this pathway was also reduced. Conclusion: Collectively, we confirmed that SPIONs are highly efficient nanocarriers for nucleic acids, on which the loading of miR-326 inhibited the activation of the GPR91/STAT3/VEGF signaling pathway and significantly attenuated the activity of stem cells in endometrial carcinoma, both in vitro and in vivo.
Collapse
Affiliation(s)
- Yongtao Gao
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People's Republic of China
| | - Haiyang Qian
- Department of Imaging, Dahua Hospital, Shanghai, 200237, People's Republic of China
| | - Xue Tang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People's Republic of China
| | - Xiling Du
- School of Life Science and Technology, Tongji University, Shanghai 200092, People's Republic of China
| | - Gang Wang
- Department of Imaging, Dahua Hospital, Shanghai, 200237, People's Republic of China
| | - Hairong Zhang
- Department of Imaging, Dahua Hospital, Shanghai, 200237, People's Republic of China
| | - Fei Ye
- Department of Imaging, Dahua Hospital, Shanghai, 200237, People's Republic of China
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, People's Republic of China
| |
Collapse
|
11
|
Peruzzotti-Jametti L, Pluchino S. Targeting Mitochondrial Metabolism in Neuroinflammation: Towards a Therapy for Progressive Multiple Sclerosis. Trends Mol Med 2018; 24:838-855. [DOI: 10.1016/j.molmed.2018.07.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 02/07/2023]
|
12
|
Zhang H, Zheng J, Lin J, Chen J, Yu Z, Chen C, Liu T. miR-758 mediates oxLDL-dependent vascular endothelial cell damage by suppressing the succinate receptor SUCNR1. Gene 2018; 663:1-8. [PMID: 29660520 DOI: 10.1016/j.gene.2018.04.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 04/05/2018] [Accepted: 04/11/2018] [Indexed: 12/13/2022]
Abstract
Atherosclerosis is a vascular disease associated with ageing, and its occurrence and development are closely related to the vascular inflammatory response. Oxidized low-density lipoprotein (oxLDL) has distinct effects in atherosclerosis. We aimed to determine the mechanisms underlying these effects. microRNAs including miR-758 were differentially expressed in oxLDL-treated HUVECs or HAECs. Luciferase reporter assay results indicated that SUCNR1 is an important target of miR-758. Expression of SUCNR1 and its downstream components was decreased significantly in ApoE-/- mice. Overexpression of miR-758 could suppress HUVEC proliferation by cell cycle arrest at the G0/G1 phase. miR-758 was overexpressed on HUVECs with markedly reduced capillary tubule formation capacity. Overexpression of miR-758 on HUVECs or HAECs could significantly reduce SUCNR1 (GPR91), SATA3, phosphorylated STAT3 (p-STAT3), and EVGF levels. Thus, oxLDL likely damages vascular endothelial cells by modulating the DLK1-DIO3 genomic imprinted microRNA cluster component miR-758, thereby suppressing expression of SUCNR1/GPR91 and its downstream components.
Collapse
Affiliation(s)
- Hu Zhang
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China
| | - Jiajia Zheng
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China
| | - Jiajia Lin
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China
| | - Jiulin Chen
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China
| | - Zhihua Yu
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China
| | - Chuan Chen
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China.
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China; Department of Pathology, Yale University School of Medicine, CT 06520, USA.
| |
Collapse
|
13
|
Riddy DM, Delerive P, Summers RJ, Sexton PM, Langmead CJ. G Protein–Coupled Receptors Targeting Insulin Resistance, Obesity, and Type 2 Diabetes Mellitus. Pharmacol Rev 2017; 70:39-67. [DOI: 10.1124/pr.117.014373] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/13/2017] [Indexed: 12/18/2022] Open
|
14
|
van Diepen JA, Robben JH, Hooiveld GJ, Carmone C, Alsady M, Boutens L, Bekkenkamp-Grovenstein M, Hijmans A, Engelke UFH, Wevers RA, Netea MG, Tack CJ, Stienstra R, Deen PMT. SUCNR1-mediated chemotaxis of macrophages aggravates obesity-induced inflammation and diabetes. Diabetologia 2017; 60:1304-1313. [PMID: 28382382 PMCID: PMC5487589 DOI: 10.1007/s00125-017-4261-z] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/28/2017] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Obesity induces macrophages to drive inflammation in adipose tissue, a crucial step towards the development of type 2 diabetes. The tricarboxylic acid (TCA) cycle intermediate succinate is released from cells under metabolic stress and has recently emerged as a metabolic signal induced by proinflammatory stimuli. We therefore investigated whether succinate receptor 1 (SUCNR1) could play a role in the development of adipose tissue inflammation and type 2 diabetes. METHODS Succinate levels were determined in human plasma samples from individuals with type 2 diabetes and non-diabetic participants. Succinate release from adipose tissue explants was studied. Sucnr1 -/- and wild-type (WT) littermate mice were fed a high-fat diet (HFD) or low-fat diet (LFD) for 16 weeks. Serum metabolic variables, adipose tissue inflammation, macrophage migration and glucose tolerance were determined. RESULTS We show that hypoxia and hyperglycaemia independently drive the release of succinate from mouse adipose tissue (17-fold and up to 18-fold, respectively) and that plasma levels of succinate were higher in participants with type 2 diabetes compared with non-diabetic individuals (+53%; p < 0.01). Sucnr1 -/- mice had significantly reduced numbers of macrophages (0.56 ± 0.07 vs 0.92 ± 0.15 F4/80 cells/adipocytes, p < 0.05) and crown-like structures (0.06 ± 0.02 vs 0.14 ± 0.02, CLS/adipocytes p < 0.01) in adipose tissue and significantly improved glucose tolerance (p < 0.001) compared with WT mice fed an HFD, despite similarly increased body weights. Consistently, macrophages from Sucnr1 -/- mice showed reduced chemotaxis towards medium collected from apoptotic and hypoxic adipocytes (-59%; p < 0.05). CONCLUSIONS/INTERPRETATION Our results reveal that activation of SUCNR1 in macrophages is important for both infiltration and inflammation of adipose tissue in obesity, and suggest that SUCNR1 is a promising therapeutic target in obesity-induced type 2 diabetes. DATA AVAILABILITY The dataset generated and analysed during the current study is available in GEO with the accession number GSE64104, www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE64104 .
Collapse
Affiliation(s)
- Janna A van Diepen
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Joris H Robben
- Department of Physiology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Guido J Hooiveld
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
| | - Claudia Carmone
- Department of Physiology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Mohammad Alsady
- Department of Physiology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Lily Boutens
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
| | | | - Anneke Hijmans
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Udo F H Engelke
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ron A Wevers
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mihai G Netea
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Cees J Tack
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rinke Stienstra
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
| | - Peter M T Deen
- Department of Physiology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands.
| |
Collapse
|
15
|
Hu J, Li T, Du X, Wu Q, Le YZ. G protein-coupled receptor 91 signaling in diabetic retinopathy and hypoxic retinal diseases. Vision Res 2017; 139:59-64. [PMID: 28539261 DOI: 10.1016/j.visres.2017.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 05/01/2017] [Accepted: 05/03/2017] [Indexed: 12/25/2022]
Abstract
G protein-coupled receptor 91 (GPR91) is a succinate-specific receptor and activation of GPR91 could initiate a complex signal transduction cascade and upregulate inflammatory and pro-angiogenic cytokines. In the retina, GPR91 is predominately expressed in ganglion cells, a major cellular entity involved in the pathogenesis of diabetic retinopathy (DR) and other hypoxic retinal diseases. During the development of DR and retinopathy of prematurity (ROP), chronic hypoxia causes an increase in the levels of local succinate. Succinate-mediated GPR91 activation upregulates vascular endothelial growth factor (VEGF) through ERK1/2-C/EBP β (c-Fos) and/or ERK1/2-COX-2/PGE2 signaling pathways, which in turn, leads to the breakdown of blood-retina barriers in these disorders. In this review, we will have a brief introduction of GPR91 and its biological functions and a more detailed discussion about the role and mechanisms of GPR91 in DR and ROP. A better understanding of GPR91 regulation may be of great significance in identifying new biomarkers and drug targets for the prediction and treatment of DR, ROP, and hypoxic retinal diseases.
Collapse
Affiliation(s)
- Jianyan Hu
- Department of Ophthalmology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China
| | - Tingting Li
- Department of Ophthalmology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China
| | - Xinhua Du
- Department of Ophthalmology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China
| | - Qiang Wu
- Department of Ophthalmology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China.
| | - Yun-Zheng Le
- Department of Medicine Endocrinology, Cell Biology, and Ophthalmology and Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| |
Collapse
|
16
|
Rubić-Schneider T, Carballido-Perrig N, Regairaz C, Raad L, Jost S, Rauld C, Christen B, Wieczorek G, Kreutzer R, Dawson J, Lametschwandner G, Littlewood-Evans A, Carballido JM. GPR91 deficiency exacerbates allergic contact dermatitis while reducing arthritic disease in mice. Allergy 2017; 72:444-452. [PMID: 27527650 PMCID: PMC5324651 DOI: 10.1111/all.13005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2016] [Indexed: 12/12/2022]
Abstract
Background Succinate, in addition to its role as an intermediary of the citric acid cycle, acts as an alarmin, initiating and propagating danger signals resulting from tissue injury or inflammatory stimuli. The contribution of this immune sensing pathway to the development of allergic and inflammatory responses is unknown. Methods Ear thickness of wild‐type (wt) and Sucnr1‐deficient (Sucnr1−/−) mice, sensitized and challenged with oxazolone, was used as a criterion to assess the relevance of SUCNR1/GPR91 expression mediating allergic contact dermatitis (ACD). Results obtained in this system were contrasted with data generated using passive cutaneous anaphylaxis, ovalbumin‐induced asthma and arthritis models. Results We found augmented ACD reactions in Sucnr1−/− mice. This observation correlated with increased mast cell activation in vitro and in vivo. However, exacerbated mast cell activation in Sucnr1−/− mice did not contribute to the enhancement of asthma or arthritis and seemed to be due to alterations during mast cell development as augmented mast cell responses could be recapitulated in wt mast cells differentiated in the absence of succinate. Conclusions A deficiency in succinate sensing during mast cell development confers these cells with a hyperactive phenotype. Such a phenomenon does not translate into exacerbation of asthma or mast cell‐dependent arthritis. On the contrary, the fact that Sucnr1−/− mice developed reduced arthritic disease, using two different in vivo models, indicates that GPR91 antagonists may have therapeutic potential for the treatment of allergic and autoimmune diseases.
Collapse
Affiliation(s)
- T. Rubić-Schneider
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
- Former NIBR; Vienna Austria
| | - N. Carballido-Perrig
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
- Former NIBR; Vienna Austria
| | - C. Regairaz
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | - L. Raad
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | | | - C. Rauld
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | - B. Christen
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | - G. Wieczorek
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | - R. Kreutzer
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | - J. Dawson
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
| | | | | | - J. M. Carballido
- Novartis Institutes for Biomedical Research (NIBR); Basel Switzerland
- Former NIBR; Vienna Austria
| |
Collapse
|
17
|
Arjunan P, Gnanaprakasam JP, Ananth S, Romej MA, Rajalakshmi VK, Prasad PD, Martin PM, Gurusamy M, Thangaraju M, Bhutia YD, Ganapathy V. Increased Retinal Expression of the Pro-Angiogenic Receptor GPR91 via BMP6 in a Mouse Model of Juvenile Hemochromatosis. Invest Ophthalmol Vis Sci 2016; 57:1612-9. [PMID: 27046124 PMCID: PMC4824383 DOI: 10.1167/iovs.15-17437] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Hemochromatosis, an iron-overload disease, occurs as adult and juvenile types. Mutations in hemojuvelin (HJV), an iron-regulatory protein and a bone morphogenetic protein (BMP) coreceptor, underlie most of the juvenile type. Hjv(-/-) mice accumulate excess iron in retina and exhibit aberrant vascularization and angiomas. A succinate receptor, GPR91, is pro-angiogenic in retina. We hypothesized that Hjv(-/-) retinas have increased BMP signaling and increased GPR91 expression as the basis of angiomas. METHODS Expression of GPR91 was examined by qPCR, immunofluorescence, and Western blot in wild-type and Hjv(-/-) mouse retinas and pRPE cells. Influence of excess iron and BMP6 on GPR91 expression was investigated in ARPE-19 cells, and wild-type and Hjv(-/-) pRPE cells. Succinate was used to activate GPR91 and determine the effects of GPR91 signaling on VEGF expression. Signaling of BMP6 was studied by the expression of Smad1/5/8 and pSmad4, and the BMP-target gene Id1. The interaction of pSmad4 with GPR91 promoter was studied by ChIP. RESULTS Expression of GPR91 was higher in Hjv(-/-) retinas and RPE than in wild-type counterparts. Unexpectedly, BMP signaling was increased, not decreased, in Hjv(-/-) retinas and RPE. Bone morphogenetic protein 6 induced GPR91 in RPE, suggesting that increased BMP signaling in Hjv(-/-) retinas was likely responsible for GPR91 upregulation. Exposure of RPE to excess iron and succinate as well as BMP6 and succinate increased VEGF expression. Bone morphogenetic protein 6 promoted the interaction of pSmad4 with GPR91 promoter in RPE. CONCLUSIONS G-protein-coupled receptor 91 is a BMP6 target and Hjv deletion enhances BMP signaling in retina, thus underscoring a role for excess iron and hemochromatosis in abnormal retinal vascularization.
Collapse
Affiliation(s)
- Pachiappan Arjunan
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 2Department of Periodontics, Georgia Regents University, Augusta, Georgia, United States
| | - Jaya P Gnanaprakasam
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Sudha Ananth
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Michelle A Romej
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | | | - Puttur D Prasad
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Pamela M Martin
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Mariappan Gurusamy
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Muthusamy Thangaraju
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Yangzom D Bhutia
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 3Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States
| | - Vadivel Ganapathy
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 3Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States
| |
Collapse
|
18
|
Succinate, an intermediate in metabolism, signal transduction, ROS, hypoxia, and tumorigenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1086-1101. [PMID: 26971832 DOI: 10.1016/j.bbabio.2016.03.012] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/06/2016] [Accepted: 03/07/2016] [Indexed: 12/31/2022]
Abstract
Succinate is an important metabolite at the cross-road of several metabolic pathways, also involved in the formation and elimination of reactive oxygen species. However, it is becoming increasingly apparent that its realm extends to epigenetics, tumorigenesis, signal transduction, endo- and paracrine modulation and inflammation. Here we review the pathways encompassing succinate as a metabolite or a signal and how these may interact in normal and pathological conditions.(1).
Collapse
|
19
|
Abstract
SUCNR1 (or GPR91) belongs to the family of G protein-coupled receptors (GPCR), which represents the largest group of membrane proteins in human genome. The majority of marketed drugs targets GPCRs, directly or indirectly. SUCNR1 has been classified as an orphan receptor until a landmark study paired it with succinate, a citric acid cycle intermediate. According to the current paradigm, succinate triggers SUCNR1 signaling pathways to indicate local stress that may affect cellular metabolism. SUCNR1 implication has been well documented in renin-induced hypertension, ischemia/reperfusion injury, inflammation and immune response, platelet aggregation and retinal angiogenesis. In addition, the SUCNR1-induced increase of blood pressure may contribute to diabetic nephropathy or cardiac hypertrophy. The understanding of SUCNR1 activation, signaling pathways and functions remains largely elusive, which calls for deeper investigations. SUCNR1 shows a high potential as an innovative drug target and is probably an important regulator of basic physiology. In order to achieve the full characterization of this receptor, more specific pharmacological tools such as small-molecules modulators will represent an important asset. In this review, we describe the structural features of SUCNR1, its current ligands and putative binding pocket. We give an exhaustive overview of the known and hypothetical signaling partners of the receptor in different in vitro and in vivo systems. The link between SUCNR1 intracellular pathways and its pathophysiological roles are also extensively discussed.
Collapse
|
20
|
Li X, Guo Y, Yan W, Snyder MP, Li X. Metformin Improves Diabetic Bone Health by Re-Balancing Catabolism and Nitrogen Disposal. PLoS One 2015; 10:e0146152. [PMID: 26716870 PMCID: PMC4696809 DOI: 10.1371/journal.pone.0146152] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/13/2015] [Indexed: 12/11/2022] Open
Abstract
Objective Metformin, a leading drug used to treat diabetic patients, is reported to benefit bone homeostasis under hyperglycemia in animal models. However, both the molecular targets and the biological pathways affected by metformin in bone are not well identified or characterized. The objective of this study is to investigate the bioengergeric pathways affected by metformin in bone marrow cells of mice. Materials and Methods Metabolite levels were examined in bone marrow samples extracted from metformin or PBS -treated healthy (Wild type) and hyperglycemic (diabetic) mice using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. We applied an untargeted high performance LC-MS approach which combined multimode chromatography (ion exchange, reversed phase and hydrophilic interaction (HILIC)) and Orbitrap-based ultra-high accuracy mass spectrometry to achieve a wide coverage. A multivariate clustering was applied to reveal the global trends and major metabolite players. Results A total of 346 unique metabolites were identified, and they are grouped into distinctive clusters that reflected general and diabetes-specific responses to metformin. As evidenced by changes in the TCA and urea cycles, increased catabolism and nitrogen waste that are commonly associated with diabetes were rebalanced upon treatment with metformin. In particular, we found glutamate and succinate whose levels were drastically elevated in diabetic animals were brought back to normal levels by metformin. These two metabolites were further validated as the major targets of metformin in bone marrow stromal cells. Conclusion Overall using limited sample size, our study revealed the metabolic pathways modulated by metformin in bones which have broad implication in our understanding of bone remodeling under hyperglycemia and in finding therapeutic interventions in mammals.
Collapse
Affiliation(s)
- Xiyan Li
- Department of Genetics, Stanford University, Stanford, CA 94305–5120, United States of America
| | - Yuqi Guo
- Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, United States of America
| | - Wenbo Yan
- Department of Biology and Chemistry, Nyack College, New York, NY 10013, United States of America
| | - Michael P. Snyder
- Department of Genetics, Stanford University, Stanford, CA 94305–5120, United States of America
| | - Xin Li
- Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, United States of America
- * E-mail:
| |
Collapse
|
21
|
|
22
|
Peti-Peterdi J, Kishore BK, Pluznick JL. Regulation of Vascular and Renal Function by Metabolite Receptors. Annu Rev Physiol 2015; 78:391-414. [PMID: 26667077 DOI: 10.1146/annurev-physiol-021115-105403] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
To maintain metabolic homeostasis, the body must be able to monitor the concentration of a large number of substances, including metabolites, in real time and to use that information to regulate the activities of different metabolic pathways. Such regulation is achieved by the presence of sensors, termed metabolite receptors, in various tissues and cells of the body, which in turn convey the information to appropriate regulatory or positive or negative feedback systems. In this review, we cover the unique roles of metabolite receptors in renal and vascular function. These receptors play a wide variety of important roles in maintaining various aspects of homeostasis-from salt and water balance to metabolism-by sensing metabolites from a wide variety of sources. We discuss the role of metabolite sensors in sensing metabolites generated locally, metabolites generated at distant tissues or organs, or even metabolites generated by resident microbes. Metabolite receptors are also involved in various pathophysiological conditions and are being recognized as potential targets for new drugs. By highlighting three receptor families-(a) citric acid cycle intermediate receptors, (b) purinergic receptors, and
Collapse
Affiliation(s)
- János Peti-Peterdi
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California 90033;
| | - Bellamkonda K Kishore
- Department of Internal Medicine and Center on Aging, University of Utah Health Sciences Center, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah 84148;
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205;
| |
Collapse
|
23
|
7-Ketocholesterol increases retinal microglial migration, activation, and angiogenicity: a potential pathogenic mechanism underlying age-related macular degeneration. Sci Rep 2015; 5:9144. [PMID: 25775051 PMCID: PMC4360733 DOI: 10.1038/srep09144] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/23/2015] [Indexed: 11/26/2022] Open
Abstract
Age-related macular degeneration (AMD) has been associated with both accumulation of lipid and lipid oxidative products, as well as increased neuroinflammatory changes and microglial activation in the outer retina. However, the relationships between these factors are incompletely understood. 7-Ketocholesterol (7KCh) is a cholesterol oxidation product localized to the outer retina with prominent pro-inflammatory effects. To explore the potential relationship between 7KCh and microglial activation, we localized 7KCh and microglia to the outer retina of aged mice and investigated 7KCh effects on retinal microglia in both in vitro and in vivo systems. We found that retinal microglia demonstrated a prominent chemotropism to 7KCh and readily internalized 7KCh. Sublethal concentrations of 7KCh resulted in microglial activation and polarization to a pro-inflammatory M1 state via NLRP3 inflammasome activation. Microglia exposed to 7KCh reduced expression of neurotrophic growth factors but increased expression of angiogenic factors, transitioning to a more neurotoxic and pro-angiogenic phenotype. Finally, subretinal transplantation of 7KCh-exposed microglia promoted choroidal neovascularization (CNV) relative to control microglia in a Matrigel-CNV model. The interaction of retinal microglia with 7KCh in the aged retina may thus underlie how outer retinal lipid accumulation in intermediate AMD results in neuroinflammation that ultimately drives progression towards advanced AMD.
Collapse
|
24
|
Li T, Hu J, Du S, Chen Y, Wang S, Wu Q. ERK1/2/COX-2/PGE2 signaling pathway mediates GPR91-dependent VEGF release in streptozotocin-induced diabetes. Mol Vis 2014; 20:1109-21. [PMID: 25324681 PMCID: PMC4119234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 07/29/2014] [Indexed: 11/04/2022] Open
Abstract
PURPOSE Retinal vascular dysfunction caused by vascular endothelial growth factor (VEGF) is the major pathological change that occurs in diabetic retinopathy (DR). It has recently been demonstrated that G protein-coupled receptor 91 (GPR91) plays a major role in both vasculature development and retinal angiogenesis. In this study, we examined the signaling pathways involved in GPR91-dependent VEGF release during the early stages of retinal vascular change in streptozotocin-induced diabetes. METHODS Diabetic rats were assigned randomly to receive intravitreal injections of shRNA lentiviral particles targeting GPR91 (LV.shGPR91) or control particles (LV.shScrambled). Accumulation of succinate was assessed by gas chromatography-mass spectrometry (GC-MS). At 14 weeks, the ultrastructure and function of the retinal vessels of diabetic retinas with or without shRNA treatment were assessed using hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), and Evans blue dye permeability. The expression of GPR91, extracellular signal-regulated kinases 1 and 2 (ERK1/2) and cyclooxygenase-2 (COX-2) were measured using immunofluorescence and western blotting. COX-2 and VEGF mRNA were determined by quantitative RT-PCR. Prostaglandin E2 (PGE2) and VEGF secretion were detected using an enzyme-linked immunosorbent assay. RESULTS Succinate exhibited abundant accumulation in diabetic rat retinas. The retinal telangiectatic vessels, basement membrane thickness, and Evans blue dye permeability were attenuated by treatment with GPR91 shRNA. In diabetic rats, knockdown of GPR91 inhibited the activities of ERK1/2 and COX-2 as well as the expression of PGE2 and VEGF. Meanwhile, COX-2, PGE2, and VEGF expression was inhibited by ERK1/2 inhibitor U0126 and COX-2 inhibitor NS-398. CONCLUSIONS Our data suggest that hyperglycemia causes succinate accumulation and GPR91 activity in retinal ganglion cells, which mediate VEGF-induced retinal vascular change via the ERK1/2/COX-2/PGE2 pathway. This study highlights the signaling pathway as a potential target for intervention in DR.
Collapse
Affiliation(s)
- Tingting Li
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Jianyan Hu
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Shanshan Du
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Yongdong Chen
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Shuai Wang
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Qiang Wu
- Department of Ophthalmology, the Sixth People’s Hospital, Shanghai Jiaotong University, Shanghai, China,Shanghai Key Laboratory of Diabetes Mellitus, Shanghai, China
| |
Collapse
|
25
|
Unsuspected task for an old team: succinate, fumarate and other Krebs cycle acids in metabolic remodeling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1330-7. [PMID: 24699309 DOI: 10.1016/j.bbabio.2014.03.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/17/2014] [Accepted: 03/25/2014] [Indexed: 12/15/2022]
Abstract
Seventy years from the formalization of the Krebs cycle as the central metabolic turntable sustaining the cell respiratory process, key functions of several of its intermediates, especially succinate and fumarate, have been recently uncovered. The presumably immutable organization of the cycle has been challenged by a number of observations, and the variable subcellular location of a number of its constitutive protein components is now well recognized, although yet unexplained. Nonetheless, the most striking observations have been made in the recent period while investigating human diseases, especially a set of specific cancers, revealing the crucial role of Krebs cycle intermediates as factors affecting genes methylation and thus cell remodeling. We review here the recent advances and persisting incognita about the role of Krebs cycle acids in diverse aspects of cellular life and human pathology.
Collapse
|