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Sheng X, Xia Z, Yang H, Hu R. The ubiquitin codes in cellular stress responses. Protein Cell 2024; 15:157-190. [PMID: 37470788 PMCID: PMC10903993 DOI: 10.1093/procel/pwad045] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/04/2023] [Indexed: 07/21/2023] Open
Abstract
Ubiquitination/ubiquitylation, one of the most fundamental post-translational modifications, regulates almost every critical cellular process in eukaryotes. Emerging evidence has shown that essential components of numerous biological processes undergo ubiquitination in mammalian cells upon exposure to diverse stresses, from exogenous factors to cellular reactions, causing a dazzling variety of functional consequences. Various forms of ubiquitin signals generated by ubiquitylation events in specific milieus, known as ubiquitin codes, constitute an intrinsic part of myriad cellular stress responses. These ubiquitination events, leading to proteolytic turnover of the substrates or just switch in functionality, initiate, regulate, or supervise multiple cellular stress-associated responses, supporting adaptation, homeostasis recovery, and survival of the stressed cells. In this review, we attempted to summarize the crucial roles of ubiquitination in response to different environmental and intracellular stresses, while discussing how stresses modulate the ubiquitin system. This review also updates the most recent advances in understanding ubiquitination machinery as well as different stress responses and discusses some important questions that may warrant future investigation.
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Affiliation(s)
- Xiangpeng Sheng
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
- State Key Laboratory of Animal Disease Control, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhixiong Xia
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hanting Yang
- Department of Neurology, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Ronggui Hu
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
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Pan H, Huan C, Hou Y, Yan P, Yang F, Jiang L, Gao S. Porcine IGFBP3 promotes porcine circovirus type 2 replication via PERK/eIF2α mediated DNA damage. Vet Microbiol 2023; 287:109897. [PMID: 37922860 DOI: 10.1016/j.vetmic.2023.109897] [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: 07/10/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/07/2023]
Abstract
The infection of porcine circovirus type 2 (PCV2) triggers activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathway and leads to DNA damage. Insulin-like growth factor-binding protein 3 (IGFBP3) may interact with the endoplasmic reticulum (ER). It remains unclear whether IGFBP3 regulates DNA damage via ER stress to mediate PCV2 replication. In this study, we observed an upregulation of porcine IGFBP3 expression during PCV2 infection, and overexpression of IGFBP3 enhanced the expression of PCV2 Cap protein, PCV2 DNA copy number, and viral titers in PK-15 B6 cells and 3D4/21 cells. Additionally, overexpression of IGFBP3 induced an increase in the DNA damage marker γH2AX by activating the PERK/eIF2α pathway without concomitant activation of ATF4, IRE1α, and ATF6α/GRP78 pathways in PK-15 B6 cells and 3D4/21 cells. Knockdown of IGFBP3 had a reverse effect on PCV2 replication in PK-15 B6 cells and 3D4/21 cells. Furthermore, treatment with etoposide enhanced PCV2 replication while KU57788 decreased it. GSK2606414 and salubrinal limited both DNA damage and viral replication. Therefore, our findings suggest that porcine IGFBP3 promotes PCV2 replication through the PERK/eIF2α pathway-mediated induction of DNA damage in PK-15 B6 cells and 3D4/21 cells. Our study provides a basis for exploring novel antiviral strategies via the extensive understanding of the relationships between host cellular proteins and viral replication.
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Affiliation(s)
- Haochun Pan
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Changchao Huan
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Yutong Hou
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Ping Yan
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Fan Yang
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Luyao Jiang
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China
| | - Song Gao
- Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China; College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Key Laboratory of Avian Bioproduct Development, Ministry of Agriculture and Rural Affairs, Yangzhou 225009, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, China.
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Gilloteaux J, De Swert K, Suain V, Nicaise C. Thalamic Neuron Resilience during Osmotic Demyelination Syndrome (ODS) Is Revealed by Primary Cilium Outgrowth and ADP-ribosylation factor-like protein 13B Labeling in Axon Initial Segment. Int J Mol Sci 2023; 24:16448. [PMID: 38003639 PMCID: PMC10671465 DOI: 10.3390/ijms242216448] [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: 10/22/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
A murine osmotic demyelinating syndrome (ODS) model was developed through chronic hyponatremia, induced by desmopressin subcutaneous implants, followed by precipitous sodium restoration. The thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) relay nuclei were the most demyelinated regions where neuroglial damage could be evidenced without immune response. This report showed that following chronic hyponatremia, 12 h and 48 h time lapses after rebalancing osmolarity, amid the ODS-degraded outskirts, some resilient neuronal cell bodies built up primary cilium and axon hillock regions that extended into axon initial segments (AIS) where ADP-ribosylation factor-like protein 13B (ARL13B)-immunolabeled rod-like shape content was revealed. These AIS-labeled shaft lengths appeared proportional with the distance of neuronal cell bodies away from the ODS damaged epicenter and time lapses after correction of hyponatremia. Fine structure examination verified these neuron abundant transcriptions and translation regions marked by the ARL13B labeling associated with cell neurotubules and their complex cytoskeletal macromolecular architecture. This necessitated energetic transport to organize and restore those AIS away from the damaged ODS core demyelinated zone in the murine model. These labeled structures could substantiate how thalamic neuron resilience occurred as possible steps of a healing course out of ODS.
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Affiliation(s)
- Jacques Gilloteaux
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
- Department of Anatomical Sciences, St George’s University School of Medicine, Newcastle upon Tyne NE1 JG8, UK
| | - Kathleen De Swert
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
| | - Valérie Suain
- Laboratoire d’Histologie Générale, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium;
| | - Charles Nicaise
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
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Gilloteaux J, De Swert K, Suain V, Brion JP, Nicaise C. Loss of Ephaptic Contacts in the Murine Thalamus during Osmotic Demyelination Syndrome. Ultrastruct Pathol 2023; 47:398-423. [PMID: 37477534 DOI: 10.1080/01913123.2023.2232452] [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: 04/25/2023] [Revised: 06/10/2023] [Accepted: 06/29/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND AND AIM A murine model mimicking osmotic demyelination syndrome (ODS) revealed with histology in the relay posterolateral (VPL) and ventral posteromedial (VPM) thalamic nuclei adjoined nerve cell bodies in chronic hyponatremia, amongst the damaged 12 h and 48 h after reinstatement of osmolality. This report aims to verify and complement with ultrastructure other neurophysiology, immunohistochemistry, and molecular biochemistry data to assess the connexin-36 protein, as part of those hinted close contacts.This ODS investigation included four groups of mice: Sham (NN; n = 13), hyponatremic (HN; n = 11), those sacrificed 12 h after a fast restoration of normal natremia (ODS12h; n = 6) and mice sacrificed 48 h afterward, or ODS48 h (n = 9). Out of these, thalamic zones samples included NN (n = 2), HN (n = 2), ODS12h (n = 3) and ODS48h (n = 3). RESULTS Ultrastructure illustrated junctions between nerve cell bodies that were immunolabeled with connexin36 (Cx36) with light microscopy and Western blots. These cell's junctions were reminiscent of low resistance junctions characterized in other regions of the CNS with electrophysiology. Contiguous neurons showed neurolemma contacts in intact and damaged tissues according to their location in the ODS zones, at 12 h and 48 h post correction along with other demyelinating alterations. Neurons and ephaptic contact measurements indicated the highest alterations, including nerve cell necrosis in the ODS epicenter and damages decreased toward the outskirts of the demyelinated zone. CONCLUSION Ephapses contained C × 36between intact or ODS injured neurons in the thalamus appeared to be resilient beyond the core degraded tissue injuries. These could maintain intercellular ionic and metabolite exchanges between these lesser injured regions and, thus, would partake to some brain plasticity repairs.
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Affiliation(s)
- Jacques Gilloteaux
- Department of Medicine, URPHyM, NARILIS, Université de Namur, Namur, Belgium
- Department of Anatomical Sciences, St George's University School of Medicine, Newcastle Upon Tyne, UK
| | - Kathleen De Swert
- Department of Medicine, URPHyM, NARILIS, Université de Namur, Namur, Belgium
| | - Valérie Suain
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Charles Nicaise
- Department of Medicine, URPHyM, NARILIS, Université de Namur, Namur, Belgium
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Sterns RH, Rondon-Berrios H, Adrogué HJ, Berl T, Burst V, Cohen DM, Christ-Crain M, Cuesta M, Decaux G, Emmett M, Garrahy A, Gankam-Kengne F, Hix JK, Hoorn EJ, Kamel KS, Madias NE, Peri A, Refardt J, Rosner MH, Sherlock M, Silver SM, Soupart A, Thompson CJ, Verbalis JG. Treatment Guidelines for Hyponatremia: Stay the Course. Clin J Am Soc Nephrol 2023; 19:01277230-990000000-00180. [PMID: 37379081 PMCID: PMC10843202 DOI: 10.2215/cjn.0000000000000244] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/22/2023] [Indexed: 06/29/2023]
Abstract
International guidelines designed to minimize the risk of complications that can occur when correcting severe hyponatremia have been widely accepted for a decade. On the basis of the results of a recent large retrospective study of patients hospitalized with hyponatremia, it has been suggested that hyponatremia guidelines have gone too far in limiting the rate of rise of the serum sodium concentration; the need for therapeutic caution and frequent monitoring of the serum sodium concentration has been questioned. These assertions are reminiscent of a controversy that began many years ago. After reviewing the history of that controversy, the evidence supporting the guidelines, and the validity of data challenging them, we conclude that current safeguards should not be abandoned. To do so would be akin to discarding your umbrella because you remained dry in a rainstorm. The authors of this review, who represent 20 medical centers in nine countries, have all contributed significantly to the literature on the subject. We urge clinicians to continue to treat severe hyponatremia cautiously and to wait for better evidence before adopting less stringent therapeutic limits.
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Affiliation(s)
- Richard H. Sterns
- University of Rochester School of Medicine and Dentistry, Rochester, New York
- Rochester General Hospital, Rochester, New York
| | | | | | - Tomas Berl
- University of Colorado Aschutz School of Medicine, Aurora, Colorado
| | - Volker Burst
- University of Cologne Faculty of Medicine, Cologne, Germany
| | | | | | | | - Guy Decaux
- Erasmus University Hospital, Brussels, Belgium
| | | | | | | | - John K. Hix
- Rochester General Hospital, Rochester, New York
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6
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Gankam Kengne F. Adaptation of the Brain to Hyponatremia and Its Clinical Implications. J Clin Med 2023; 12:jcm12051714. [PMID: 36902500 PMCID: PMC10002753 DOI: 10.3390/jcm12051714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/12/2023] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
Hyponatremia is the most common electrolyte disorder, occurring in up to 25% of hospitalized patients. Hypo-osmotic hyponatremia when severe and left untreated invariably results in cell swelling, which can lead to fatal consequences, especially in the central nervous system. The brain is particularly vulnerable to the consequences of decreased extracellular osmolarity; because of being encased in the rigid skull, it cannot withstand persistent swelling. Moreover, serum sodium is the major determinant of extracellular ionic balance, which in turn governs crucial brain functions such as the excitability of neurons. For these reasons, the human brain has developed specific ways to adapt to hyponatremia and prevent brain edema. On the other hand, it is well known that rapid correction of chronic and severe hyponatremia can lead to brain demyelination, a condition known as osmotic demyelination syndrome. In this paper, we will discuss the mechanisms of brain adaptation to acute and chronic hyponatremia and the neurological symptoms of these conditions as well as the pathophysiology and prevention of osmotic demyelination syndrome.
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7
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Par3 promotes breast cancer invasion and migration through pull tension and protein nanoparticle-induced osmotic pressure. Biomed Pharmacother 2022; 155:113739. [PMID: 36179489 DOI: 10.1016/j.biopha.2022.113739] [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: 08/03/2022] [Revised: 09/13/2022] [Accepted: 09/21/2022] [Indexed: 11/20/2022] Open
Abstract
Cancer cell invasion and metastasis are closely related to intracellular tension. The cell-polarity protein, Par3, is a mechanical transmitter that affects cytoskeletal forces and determines breast cancer aggressiveness. Increased Par3 tension caused by aPKC inactivation is involved in filopodia and lamellipodia formation. Blocking the connection between Par3 and aPKC increases breast cancer aggressiveness both in vitro and in vivo. Meanwhile, aPKC-induced Par3 cytoplasmic translocation results in JAM-A phase separation and microfilament depolymerization, which is associated with increased intracellular protein nanoparticle-induced osmotic pressure. This study demonstrated the effects of aPKC on Par3 tension and osmotic pressure in breast cancer metastasis, and introduced Par3-associated mechanical mechanisms as potential targets for breast cancer treatment.
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8
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The Blood–Brain Barrier—A Key Player in Multiple Sclerosis Disease Mechanisms. Biomolecules 2022; 12:biom12040538. [PMID: 35454127 PMCID: PMC9025898 DOI: 10.3390/biom12040538] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 02/07/2023] Open
Abstract
Over the past decade, multiple sclerosis (MS), a chronic neuroinflammatory disease with severe personal and social consequences, has undergone a steady increase in incidence and prevalence rates worldwide. Despite ongoing research and the development of several novel therapies, MS pathology remains incompletely understood, and the prospect for a curative treatment continues to be unpromising in the near future. A sustained research effort, however, should contribute to a deeper understanding of underlying disease mechanisms, which will undoubtedly yield improved results in drug development. In recent years, the blood–brain barrier (BBB) has increasingly become the focus of many studies as it appears to be involved in both MS disease onset and progression. More specifically, neurovascular unit damage is believed to be involved in the critical process of CNS immune cell penetration, which subsequently favors the development of a CNS-specific immune response, leading to the classical pathological and clinical hallmarks of MS. The aim of the current narrative review is to merge the relevant evidence on the role of the BBB in MS pathology in a comprehensive and succinct manner. Firstly, the physiological structure and functions of the BBB as a component of the more complex neurovascular unit are presented. Subsequently, the authors review the specific alteration of the BBB encountered in different stages of MS, focusing on both the modifications of BBB cells in neuroinflammation and the CNS penetration of immune cells. Finally, the currently accepted theories on neurodegeneration in MS are summarized.
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McCormick JJ, King KE, Rutherford MM, Meade RD, Notley SR, Akerman AP, Dokladny K, Kenny GP. Effect of extracellular hyperosmolality during normothermia and hyperthermia on the autophagic response in peripheral blood mononuclear cells from young men. J Appl Physiol (1985) 2022; 132:995-1004. [PMID: 35238651 DOI: 10.1152/japplphysiol.00661.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heat-stress induced dehydration is associated with extracellular hyperosmolality. To counteract the associated stress, cells employ cytoprotective mechanisms, including autophagy, however, the autophagic response to hyperosmotic stress has yet to be evaluated in humans. Thus, we investigated autophagy and associated cellular stress pathways (the heat shock response [HSR], apoptosis, and the acute inflammatory response) to isosmotic and hyperosmotic conditions with and without hyperthermia in twelve young men (mean [SD]; 25 [5] years). Participants received a 90-min intravenous infusion of either isosmotic (ISO; 0.9% NaCl; serum osmolality of 293 [4] mOsm/kg) or hyperosmotic (HYP; 3.0% NaCl; 300 [6] mOsm/kg) saline, followed by passive whole-body heating using a water perfused suit to increase esophageal temperature by ~0.8⁰C. Peripheral blood mononuclear cells were harvested at baseline (pre-infusion), post-infusion, and after heating, and changes in protein content were analyzed via Western blotting. Post-infusion, the LC3-II/I ratio was higher in HYP compared to ISO infusion (p<0.001), although no other protein changes were observed (all p>0.050). Following passive heating, autophagy increased in HYP, as demonstrated by an increase in LC3-II from baseline (p=0.004) and an elevated LC3-II/I ratio compared to ISO (p=0.035), and a decrease in p62 when compared to the ISO condition (p=0.019). This was accompanied by an elevation in cleaved caspase-3 following heating in the HYP condition (p<0.010), however, the HSR and acute inflammatory response did not change under any condition (all p>0.050). Taken together, our findings indicate that serum hyperosmolality induces autophagy and apoptotic signaling during mild hyperthermia with minimal autophagic activation during normothermia.
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Affiliation(s)
- James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Maura M Rutherford
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.,Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, United States
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Karol Dokladny
- Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, United States
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.,Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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Miyata Y, Fuse H, Tokumoto S, Hiki Y, Deviatiiarov R, Yoshida Y, Yamada TG, Cornette R, Gusev O, Shagimardanova E, Funahashi A, Kikawada T. Cas9-mediated genome editing reveals a significant contribution of calcium signaling pathways to anhydrobiosis in Pv11 cells. Sci Rep 2021; 11:19698. [PMID: 34611198 PMCID: PMC8492635 DOI: 10.1038/s41598-021-98905-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 09/16/2021] [Indexed: 01/01/2023] Open
Abstract
Pv11 is an insect cell line established from the midge Polypedilum vanderplanki, whose larval form exhibits an extreme desiccation tolerance known as anhydrobiosis. Pv11 itself is also capable of anhydrobiosis, which is induced by trehalose treatment. Here we report the successful construction of a genome editing system for Pv11 cells and its application to the identification of signaling pathways involved in anhydrobiosis. Using the Cas9-mediated gene knock-in system, we established Pv11 cells that stably expressed GCaMP3 to monitor intracellular Ca2+ mobilization. Intriguingly, trehalose treatment evoked a transient increase in cytosolic Ca2+ concentration, and further experiments revealed that the calmodulin-calcineurin-NFAT pathway contributes to tolerance of trehalose treatment as well as desiccation tolerance, while the calmodulin-calmodulin kinase-CREB pathway conferred only desiccation tolerance on Pv11 cells. Thus, our results show a critical contribution of the trehalose-induced Ca2+ surge to anhydrobiosis and demonstrate temporally different roles for each signaling pathway.
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Affiliation(s)
- Yugo Miyata
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
| | - Hiroto Fuse
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Shoko Tokumoto
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Yusuke Hiki
- Department of Biosciences and Informatics, Keio University, Yokohama, Kanagawa, Japan
| | - Ruslan Deviatiiarov
- Extreme Biology Laboratory, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yuki Yoshida
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa, Japan
| | - Takahiro G Yamada
- Department of Biosciences and Informatics, Keio University, Yokohama, Kanagawa, Japan
| | - Richard Cornette
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
| | - Oleg Gusev
- Extreme Biology Laboratory, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
- Laboratory for Transcriptome Technology, RIKEN Center for Integrative Medical Sciences, RIKEN, Yokohama, Kanagawa, Japan
| | - Elena Shagimardanova
- Extreme Biology Laboratory, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Akira Funahashi
- Department of Biosciences and Informatics, Keio University, Yokohama, Kanagawa, Japan
| | - Takahiro Kikawada
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan.
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
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11
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Saunders I, Williams DM, Ruslan AM, Min T. Osmotic demyelination syndrome following slow correction of hyponatraemia. BMJ Case Rep 2021; 14:e241407. [PMID: 34373247 PMCID: PMC8354253 DOI: 10.1136/bcr-2020-241407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2021] [Indexed: 01/10/2023] Open
Abstract
Hyponatraemia is the most common electrolyte disturbance observed in hospital inpatients. We report a 90-year-old woman admitted generally unwell following a fall with marked confusion. Examination revealed a tender suprapubic region, and investigations observed elevated inflammatory markers and bacteriuria. Admission investigations demonstrated a serum sodium of 110 mmol/L with associated serum osmolality 236 mmol/kg and urine osmolality 346 mmol/kg. She was treated for hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone (SIADH) and urosepsis. However, her serum sodium failed to normalise despite fluid restriction, necessitating treatment with demeclocycline and hypertonic saline. Despite slow reversal of hyponatraemia over 1 month, the patient developed generalised seizures with pontine and thalamic changes on MRI consistent with osmotic demyelination syndrome (ODS). This case highlights the risk of ODS, a rare but devastating consequence of hyponatraemia treatment, despite cautious sodium correction.
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Affiliation(s)
| | | | | | - Thinzar Min
- Diabetes and Endocrinology, Singleton Hospital, Swansea, UK
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12
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Bai Y, Liu Y. Illuminating Protein Phase Separation: Reviewing Aggregation-Induced Emission, Fluorescent Molecular Rotor and Solvatochromic Fluorophore based Probes. Chemistry 2021; 27:14564-14576. [PMID: 34342071 DOI: 10.1002/chem.202102344] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Indexed: 11/09/2022]
Abstract
Protein phase separation process involving protein unfolding, misfolding, condensation and aggregation etc. has been associated with numerous human degenerative diseases. The complexity in protein conformational transitions results in multi-step and multi-species biochemical pathways upon protein phase separation. Recent progresses in designing novel fluorescent probes have unraveled the enriched details of phase separated proteins and provided mechanistic insights towards disease pathology. In this review, we summarized the design and characterizations of fluorescent probes that selectively illuminate proteins at different phase separated states with a focus on aggregation-induced emission probes, fluorescent molecular rotors, and solvatochromic fluorophores. Inspired by these pioneering works, a design blueprint was proposed to further develop fluorescent probes that can potentially shed light on the unresolved protein phase separated states in the future.
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Affiliation(s)
- Yulong Bai
- Dalian Institute of Chemical Physics, Chemistry, 457 Zhongshan Road, 116023, Dalian, CHINA
| | - Yu Liu
- Chinese Academy of Sciences, Dalian Institute of Chemical Physics, 457 Zhongshan Road, 116023, Dalian, CHINA
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13
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Bose P. Central pontine myelinolysis and the osmotic demyelination syndromes: an open and shut case? Acta Neurol Belg 2021; 121:849-858. [PMID: 33713026 DOI: 10.1007/s13760-021-01634-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/16/2021] [Indexed: 12/01/2022]
Abstract
Central pontine myelinolysis and extrapontine myelinolysis are collectively called the osmotic demyelination syndromes. Despite being described in 1959, there are several aspects of the disorder that remain an enigma. Animal models and neuroimaging techniques have allowed us to understand the condition better. From being a universally fatal disorder that was diagnosed post mortem, increased awareness, neuroimaging techniques and supportive care have enabled us to make the diagnosis ante-mortem. This has also led to a significant drop in associated mortality. The aim of this review is to highlight the clinical spectrum, neuroimaging findings, and recent developments.
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Affiliation(s)
- Pyari Bose
- Department of Neurology, Auckland City Hospital, Auckland, New Zealand.
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14
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Kalampokini S, Artemiadis A, Zis P, Hadjihannas L, Parpas G, Kyrri A, Hadjigeorgiou GM. Osmotic demyelination syndrome improving after immune-modulating treatment: Case report and literature review. Clin Neurol Neurosurg 2021; 208:106811. [PMID: 34358802 DOI: 10.1016/j.clineuro.2021.106811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Osmotic demyelination syndrome (ODS), which embraces central pontine and extrapontine myelinolysis, is an uncommon neurological disorder that occurs due to plasma osmotic changes. CASE PRESENTATION We present the case of a 55-year-old man, who presented with severe hyponatremia due to repeated vomiting, antidepressant treatment and consumption of large amounts of water. Fifteen days after sodium correction, the patient showed fluctuation of vigilance, dysarthria and dysphagia, tremor, cogwheel rigidity, bilateral facial palsy, ophthalmoplegia and tetraparesis. A brain MRI scan revealed extrapontine and later on pontine myelinolysis. He received intravenous steroids and subsequently immunoglobulin. His status began to improve gradually after completion of immunoglobulin and at three month-follow-up had no neurological deficit. LITERATURE REVIEW A comprehensive literature search of all reported ODS cases that received immunoglobulin, steroids or plasmapheresis was conducted in the electronic databases PubMed and Web of science. CONCLUSIONS Improvement was seen in most cases that received immunoglobulin either during treatment or in the first days after treatment. With regard to steroids, although most cases reported improvement in the following months their effect on the outcome is unclear. Most cases treated with plasmapheresis reported favorable outcome at variable follow-up time. Immunoglobulin and steroids have immunomodulatory effects, which could contribute to promotion of myelin repair in ODS. Plasmapheresis has effects on the immune system beyond removing myelinotoxins from the circulation. More evidence is required to support their use in ODS. However, in view of the disease severity, these therapeutic choices should be considered in the clinical management of ODS.
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Affiliation(s)
- Stefania Kalampokini
- Medical School, University of Cyprus, Nicosia, Cyprus; Department of Neurology, Nicosia General Hospital, Nicosia, Cyprus.
| | - Artemios Artemiadis
- Medical School, University of Cyprus, Nicosia, Cyprus; Department of Neurology, Nicosia General Hospital, Nicosia, Cyprus
| | - Panagiotis Zis
- Medical School, University of Cyprus, Nicosia, Cyprus; Department of Neurology, Nicosia General Hospital, Nicosia, Cyprus
| | - Linos Hadjihannas
- Department of Internal medicine, Nicosia General Hospital, Nicosia, Cyprus
| | - Giorgos Parpas
- Department of Internal medicine, Nicosia General Hospital, Nicosia, Cyprus
| | - Artemis Kyrri
- Department of Internal medicine, Nicosia General Hospital, Nicosia, Cyprus
| | - Georgios M Hadjigeorgiou
- Medical School, University of Cyprus, Nicosia, Cyprus; Department of Neurology, Nicosia General Hospital, Nicosia, Cyprus
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15
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Wang P, Wu YJ, Sun ML. Decrease of an intracellular organic osmolyte contributes to the cytotoxicity of organophosphate in neuroblastoma cells in vitro. Toxicology 2021; 453:152725. [PMID: 33617914 DOI: 10.1016/j.tox.2021.152725] [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: 08/11/2020] [Revised: 02/06/2021] [Accepted: 02/13/2021] [Indexed: 11/29/2022]
Abstract
Organophosphorus compounds (OP) causes prominent delayed neuropathy in vivo and cytotoxicity to neuronal cells in vitro. The primary target protein of OP's neurotoxicity is neuropathy target esterase (NTE), which can convert phosphatidylcholine (PC) to glycerophosphocholine (GPC). Recent studies reveal that autophagic cell death is important for the initiation and progression of OP-induced neurotoxicity both in vivo and in vitro. However, the mechanism of how OP induces autophagic cell death is unknown. Here it is found that GPC is an important organic osmolyte in the neuroblastoma cells, and treatment with tri-o-cresyl phosphate (TOCP), a representative OP, leads to the decrease of GPC and imbalance of extracellular and intracellular osmolality. Knockdown of GPC metabolizing enzyme glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5) reverses TOCP-induced autophagic cell death, which further supports the notion that the reduced GPC level leads to the autophagic cell death. Furthermore, it is found that autophagic cell death is due to the induction of reactive oxygen species (ROS) and mitochondrial damage by imbalance of osmolality with TOCP treatment. In summary, this study reveals that TOCP treatment decreases GPC level and intracellular osmolality, which induces ROS and mitochondrial damage and leads to the cell death and neurite degradation by autophagy. This study lays the foundation for further investigations on the potential therapeutic approaches for OP neurotoxicity or NTE mutation-related neurological diseases.
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Affiliation(s)
- Pan Wang
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China; School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Yi-Jun Wu
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China.
| | - Man-Lian Sun
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China
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16
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Scalisi J, Balau B, Deneyer L, Bouchat J, Gilloteaux J, Nicaise C. Blood-brain barrier permeability towards small and large tracers in a mouse model of osmotic demyelination syndrome. Neurosci Lett 2021; 746:135665. [DOI: 10.1016/j.neulet.2021.135665] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/17/2020] [Accepted: 01/13/2021] [Indexed: 01/01/2023]
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Wijayabandara M, Appuhamy S, Weerathunga P, Chang T. Effective treatment of osmotic demyelination syndrome with plasmapheresis: a case report and review of the literature. J Med Case Rep 2021; 15:6. [PMID: 33430956 PMCID: PMC7798224 DOI: 10.1186/s13256-020-02573-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/03/2020] [Indexed: 11/21/2022] Open
Abstract
Background Treatment options for chronic osmotic demyelination syndrome are limited to case reports and only a very few show complete recovery. We report a case of complete recovery of chronic osmotic demyelination syndrome with plasmapheresis. Case presentation A 43-year-old Sri Lankan man presented with fever, repeated vomiting, unsteady gait, increased tonicity of his right upper limb and paucity of speech for three days. He was treated in the local hospital with antibiotics and antivirals as per central nervous system infection. He had hyponatraemia, which was rapidly corrected with hypertonic saline from 97 to 119 mmol/L. He was transferred to our hospital because of progressive reduction of consciousness, rapidly worsening rigidity and bradykinesia of all four limbs and worsening dysarthria and bradyphrenia. Magnetic resonance imaging of the brain was compatible with osmotic demyelination syndrome. He was commenced on plasmapheresis twenty-two days after rapid correction of sodium. He regained independent mobility with complete resolution of rigidity, bradykinesia and speech dysfunction after five cycles of alternate day plasmapheresis. Conclusion Plasmapheresis can be considered as an effective treatment modality in chronic osmotic demyelination syndrome.
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Affiliation(s)
| | - Shenal Appuhamy
- University Medical Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka
| | - Praveen Weerathunga
- Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Thashi Chang
- Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
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18
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Gilloteaux J, Bouchat J, Brion JP, Nicaise C. The osmotic demyelination syndrome: the resilience of thalamic neurons is verified with transmission electron microscopy. Ultrastruct Pathol 2021; 44:450-480. [DOI: 10.1080/01913123.2020.1853865] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jacques Gilloteaux
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
- Department of Anatomical Sciences, St George’s University School of Medicine, KB Taylor Global Scholar’s Program at UNN, School of Health and Life Sciences, Newcastle upon Tyne, UK
| | - Joanna Bouchat
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculté de Médecine Université Libre de Bruxelles, Brussels, Belgium
| | - Charles Nicaise
- Unit of Research in Molecular Physiology (Urphym- NARILIS), Department of Medicine, Université de Namur, Namur, Belgium
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19
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Endocytic regulation of cellular ion homeostasis controls lysosome biogenesis. Nat Cell Biol 2020; 22:815-827. [PMID: 32601373 DOI: 10.1038/s41556-020-0535-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/21/2020] [Indexed: 12/24/2022]
Abstract
Lysosomes serve as cellular degradation and signalling centres that coordinate metabolism in response to intracellular cues and extracellular signals. Lysosomal capacity is adapted to cellular needs by transcription factors, such as TFEB and TFE3, which activate the expression of lysosomal and autophagy genes. Nuclear translocation and activation of TFEB are induced by a variety of conditions such as starvation, lysosome stress and lysosomal storage disorders. How these various cues are integrated remains incompletely understood. Here, we describe a pathway initiated at the plasma membrane that controls lysosome biogenesis via the endocytic regulation of intracellular ion homeostasis. This pathway is based on the exo-endocytosis of NHE7, a Na+/H+ exchanger mutated in X-linked intellectual disability, and serves to control intracellular ion homeostasis and thereby Ca2+/calcineurin-mediated activation of TFEB and downstream lysosome biogenesis in response to osmotic stress to promote the turnover of toxic proteins and cell survival.
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20
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Decaux G, Gankam Kengne F. Hypertonic saline, isotonic saline, water restriction, long loops diuretics, urea or vaptans to treat hyponatremia. Expert Rev Endocrinol Metab 2020; 15:195-214. [PMID: 32401559 DOI: 10.1080/17446651.2020.1755259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/09/2020] [Indexed: 01/08/2023]
Abstract
Introduction: Hyponatremia is the most common fluid and electrolyte abnormality. It is associated with much higher morbidity and mortality rates than found in non hyponatremic patients.Areas covered: When the physician is faced to a hyponatremic patient he first has to confirm that hyponatremia is associated with hypoosmolality. Then he must answer to a series of questions: What is its origin? Is it acute or chronic? Which treatment is the most appropriate? We will discuss the various options for the treatment of hypotonic hyponatremia. For a better comprehensive approach of the treatment we will also discuss some pathophysiological data. The use of urea in euvolemic and hypervolemic hyponatremia will be particularly discussed. Literature was reviewed from Jan 1970 to Dec 2019.Expert opinion: Prospective studies showing the benefit in decreasing morbidity by increasing SNa in patients with chronic hyponatremia should be done. These studies should also compare the efficacy and side effects of urea therapy compare to vaptans.
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Affiliation(s)
- Guy Decaux
- Department of Internal Medicine, Erasmus University Hospital, ULB, Brussels, Belgium
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21
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Astrocyte and Oligodendrocyte Cross-Talk in the Central Nervous System. Cells 2020; 9:cells9030600. [PMID: 32138223 PMCID: PMC7140446 DOI: 10.3390/cells9030600] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/23/2022] Open
Abstract
Over the last decade knowledge of the role of astrocytes in central nervous system (CNS) neuroinflammatory diseases has changed dramatically. Rather than playing a merely passive role in response to damage it is clear that astrocytes actively maintain CNS homeostasis by influencing pH, ion and water balance, the plasticity of neurotransmitters and synapses, cerebral blood flow, and are important immune cells. During disease astrocytes become reactive and hypertrophic, a response that was long considered to be pathogenic. However, recent studies reveal that astrocytes also have a strong tissue regenerative role. Whilst most astrocyte research focuses on modulating neuronal function and synaptic transmission little is known about the cross-talk between astrocytes and oligodendrocytes, the myelinating cells of the CNS. This communication occurs via direct cell-cell contact as well as via secreted cytokines, chemokines, exosomes, and signalling molecules. Additionally, this cross-talk is important for glial development, triggering disease onset and progression, as well as stimulating regeneration and repair. Its critical role in homeostasis is most evident when this communication fails. Here, we review emerging evidence of astrocyte-oligodendrocyte communication in health and disease. Understanding the pathways involved in this cross-talk will reveal important insights into the pathogenesis and treatment of CNS diseases.
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22
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Nimodipine-Dependent Protection of Schwann Cells, Astrocytes and Neuronal Cells from Osmotic, Oxidative and Heat Stress Is Associated with the Activation of AKT and CREB. Int J Mol Sci 2019; 20:ijms20184578. [PMID: 31527507 PMCID: PMC6770698 DOI: 10.3390/ijms20184578] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/06/2019] [Accepted: 09/14/2019] [Indexed: 02/08/2023] Open
Abstract
Clinical and experimental data assumed a neuroprotective effect of the calcium channel blocker nimodipine. However, it has not been proven which neuronal or glial cell types are affected by nimodipine and which mechanisms underlie these neuroprotective effects. Therefore, the aim of this study was to investigate the influence of nimodipine treatment on the in vitro neurotoxicity of different cell types in various stress models and to identify the associated molecular mechanisms. Therefore, cell lines from Schwann cells, neuronal cells and astrocytes were pretreated for 24 h with nimodipine and incubated under stress conditions such as osmotic, oxidative and heat stress. The cytotoxicity was measured via the lactate dehydrogenase (LDH) activity of cell culture supernatant. As a result, the nimodipine treatment led to a statistically significantly reduced cytotoxicity in Schwann cells and neurons during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (p ≤ 0.05), when compared to the vehicle. The cytotoxicity of astrocytes was nimodipine-dependently reduced during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (not significant). Moreover, a decreased caspase activity as well as an increased proteinkinase B (AKT) and cyclic adenosine monophosphate response element-binding protein (CREB) phosphorylation could be observed after the nimodipine treatment under different stress conditions. These results demonstrate a cell type-independent neuroprotective effect of the prophylactic nimodipine treatment, which is associated with the prevention of stress-dependent apoptosis through the activation of CREB and AKT signaling pathways and the reduction of caspase 3 activity.
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23
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Bansal LR, Zinkus T. Osmotic Demyelination Syndrome in Children. Pediatr Neurol 2019; 97:12-17. [PMID: 31128892 DOI: 10.1016/j.pediatrneurol.2019.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 03/09/2019] [Accepted: 03/20/2019] [Indexed: 11/28/2022]
Abstract
Osmotic demyelination syndrome is an acute demyelination process that usually occurs several days following an osmotic stress. This syndrome is rare in adults (0.4% to 0.56%) and even more uncommon in children. We performed a review of all reported pediatric osmotic demyelination syndrome patients from 1960 to 2018. Among all 106 cases, 49 presented with isolated central pontine myelinolysis, 30 with isolated extrapontine myelinolysis, and 27 with combined central pontine myelinolysis and extrapontine myelinolysis. There was no gender preponderance, and the highest prevalence was noted between the ages one and five years. Magnetic resonance imaging remains the diagnostic modality of choice, and diffusion tensor imaging is now increasingly used for prognostication in osmotic demyelination syndrome. Sixty percent of the children had a complete neurological recovery. Current management of osmotic demyelination syndrome in children consists of supportive medical care, steroids, and intravenous immunoglobulin. Our review of the literature supports the hypothesis that steroids and immunoglobulins are potentially helpful, although additional controlled studies are needed.
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Affiliation(s)
- Lalit R Bansal
- Division of Neurology, Children's Mercy Hospital, Kansas City, Missouri.
| | - Timothy Zinkus
- Department of Radiology, Children's Mercy Hospital, Kansas City, Missouri
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24
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Bouchat J, Gilloteaux J, Suain V, Van Vlaender D, Brion JP, Nicaise C. Ultrastructural Analysis of Thalamus Damages in a Mouse Model of Osmotic-Induced Demyelination. Neurotox Res 2019; 36:144-162. [DOI: 10.1007/s12640-019-00041-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 03/25/2019] [Accepted: 04/04/2019] [Indexed: 12/31/2022]
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25
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Nicaise C, Marneffe C, Bouchat J, Gilloteaux J. Osmotic Demyelination: From an Oligodendrocyte to an Astrocyte Perspective. Int J Mol Sci 2019; 20:E1124. [PMID: 30841618 PMCID: PMC6429405 DOI: 10.3390/ijms20051124] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 02/26/2019] [Accepted: 02/27/2019] [Indexed: 12/15/2022] Open
Abstract
Osmotic demyelination syndrome (ODS) is a disorder of the central myelin that is often associated with a precipitous rise of serum sodium. Remarkably, while the myelin and oligodendrocytes of specific brain areas degenerate during the disease, neighboring neurons and axons appear unspoiled, and neuroinflammation appears only once demyelination is well established. In addition to blood‒brain barrier breakdown and microglia activation, astrocyte death is among one of the earliest events during ODS pathology. This review will focus on various aspects of biochemical, molecular and cellular aspects of oligodendrocyte and astrocyte changes in ODS-susceptible brain regions, with an emphasis on the crosstalk between those two glial cells. Emerging evidence pointing to the initiating role of astrocytes in region-specific degeneration are discussed.
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Affiliation(s)
| | - Catherine Marneffe
- Laboratory of Glia Biology (VIB-KU Leuven Center for Brain & Disease Research), Department of Neuroscience, KU Leuven, 3000 Leuven, Belgium.
| | - Joanna Bouchat
- URPhyM-NARILIS, Université de Namur, 5000 Namur, Belgium.
| | - Jacques Gilloteaux
- URPhyM-NARILIS, Université de Namur, 5000 Namur, Belgium.
- Department of Anatomical Sciences, St George's University School of Medicine, Newcastle upon Tyne NE1 8ST, UK.
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26
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Decaux G. Approach to and management of abnormalities in plasma sodium. Acta Clin Belg 2019; 74:7-20. [PMID: 30311550 DOI: 10.1080/17843286.2018.1531616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The differential diagnosis between hypertonic, isotonic and hypotonic hyponatremia are presented. The help of some usual serum (urea, uric acid and TCO2) and urine parameters (mainly osmolality and sodium concentration) are discussed and help to determine the best treatment. Morbidity associated with untreated hyponatremia and with the different treatment available is also discussed. Who to prevent and treat ODS (osmotic demyelating syndrome) is recalled. The pathophysiology and treatment of hypernatremia are also discussed.
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Affiliation(s)
- G. Decaux
- Service de Médecine Interne, Hôpital Universitaire Erasme, Bruxelles, Belgium
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27
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Cooper JF, Spielbauer KK, Senchuk MM, Nadarajan S, Colaiácovo MP, Van Raamsdonk JM. α-synuclein expression from a single copy transgene increases sensitivity to stress and accelerates neuronal loss in genetic models of Parkinson's disease. Exp Neurol 2018; 310:58-69. [PMID: 30194957 DOI: 10.1016/j.expneurol.2018.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/25/2018] [Accepted: 09/04/2018] [Indexed: 11/28/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by the formation of α-synuclein-containing protein aggregates called Lewy bodies within the brain. A crucial role for α-synuclein in the pathogenesis of PD is also suggested by the fact that point mutations, increased copy number, or polymorphisms in the α-synuclein gene SNCA all cause or contribute to the development of PD. In addition to SNCA, an increasing number of other genes have been implicated in PD. While mutations in at least some of these genes have been shown to cause the formation of Lewy bodies, the role of α-synuclein in these genetic forms of PD remains poorly defined. Since C. elegans do not have a homolog of α-synuclein, this organism provides the opportunity to identify synergism between α-synuclein and other genes implicated in PD. To do this, we generated a novel C. elegans model in which wild-type α-synuclein is ubiquitously expressed from a single copy transgene, and examined the resulting effect on phenotypic deficits in PD deletion mutants affecting PARK2/pdr-1, PINK1/pink-1, DJ-1/djr-1.1 and ATP13A2/catp-6. While the PD deletion mutants exhibit only mild phenotypic deficits in absence of α-synuclein, expression of wild-type α-synuclein caused increased sensitivity to multiple stresses, induced deficits in dopamine-dependent behavior, and accelerated loss of dopamine neurons. Overall, these results suggest that the recessive loss of function mutations act together with α-synuclein to cause PD, and that α-synuclein lowering strategies may be effective in genetic forms of PD.
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Affiliation(s)
- Jason F Cooper
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Katie K Spielbauer
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Megan M Senchuk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | | | | | - Jeremy M Van Raamsdonk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada; Metabolic Disorders and Complications Program, and Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada.
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28
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Bryniarski MA, Yee BM, Jaffri I, Chaves LD, Yu JA, Guan X, Ghavam N, Yacoub R, Morris ME. Increased megalin expression in early type 2 diabetes: role of insulin-signaling pathways. Am J Physiol Renal Physiol 2018; 315:F1191-F1207. [PMID: 29949391 DOI: 10.1152/ajprenal.00210.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The megalin/cubilin complex is responsible for the majority of serum protein reclamation in the proximal tubules. The current study examined if decreases in their renal expression, along with the albumin recycling protein neonatal Fc receptor (FcRn) could account for proteinuria/albuminuria in the Zucker diabetic fatty rat model of type 2 diabetes. Immunoblots of renal cortex samples obtained at worsening disease stages demonstrated no loss in megalin, cubilin, or FcRn, even when proteinuria was measured. Additionally, early diabetic rats exhibited significantly increased renal megalin expression when compared with controls (adjusted P < 0.01). Based on these results, the ability of insulin to increase megalin was examined in a clonal subpopulation of the opossum kidney proximal tubule cell line. Insulin treatments (24 h, 100 nM) under high glucose conditions significantly increased megalin protein ( P < 0.0001), mRNA ( P < 0.0001), and albumin endocytosis. The effect on megalin expression was prevented with inhibitors against key effectors of insulin intracellular signaling, phosphatidylinositide 3-kinase and Akt. Studies using rapamycin to inhibit the mechanistic target of rapamycin complex 1 (mTORC1) resulted in a loss of insulin-induced megalin expression. However, subsequent evaluation demonstrated these effects were independent of initial mTORC1 suppression. The presented results provide insight into the expression of megalin, cubilin, and FcRn in type 2 diabetes, which may be impacted by elevated insulin and glucose. Furthermore, proximal tubule endocytic activity in early diabetics may be enhanced, a process that could have a significant role in proteinuria-induced renal damage.
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Affiliation(s)
- Mark A Bryniarski
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Benjamin M Yee
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Irum Jaffri
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Lee D Chaves
- Department of Internal Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo , New York
| | - Jin Ah Yu
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Xiaowen Guan
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Nazanin Ghavam
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
| | - Rabi Yacoub
- Department of Internal Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo , New York
| | - Marilyn E Morris
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo , New York
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Wang YF, Parpura V. Astroglial Modulation of Hydromineral Balance and Cerebral Edema. Front Mol Neurosci 2018; 11:204. [PMID: 29946238 PMCID: PMC6007284 DOI: 10.3389/fnmol.2018.00204] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Maintenance of hydromineral balance (HB) is an essential condition for life activity at cellular, tissue, organ and system levels. This activity has been considered as a function of the osmotic regulatory system that focuses on hypothalamic vasopressin (VP) neurons, which can reflexively release VP into the brain and blood to meet the demand of HB. Recently, astrocytes have emerged as an essential component of the osmotic regulatory system in addition to functioning as a regulator of the HB at cellular and tissue levels. Astrocytes express all the components of osmoreceptors, including aquaporins, molecules of the extracellular matrix, integrins and transient receptor potential channels, with an operational dynamic range allowing them to detect and respond to osmotic changes, perhaps more efficiently than neurons. The resultant responses, i.e., astroglial morphological and functional plasticity in the supraoptic and paraventricular nuclei, can be conveyed, physically and chemically, to adjacent VP neurons, thereby influencing HB at the system level. In addition, astrocytes, particularly those in the circumventricular organs, are involved not only in VP-mediated osmotic regulation, but also in regulation of other osmolality-modulating hormones, including natriuretic peptides and angiotensin. Thus, astrocytes play a role in local/brain and systemic HB. The adaptive astrocytic reactions to osmotic challenges are associated with signaling events related to the expression of glial fibrillary acidic protein and aquaporin 4 to promote cell survival and repair. However, prolonged osmotic stress can initiate inflammatory and apoptotic signaling processes, leading to glial dysfunction and a variety of brain diseases. Among many diseases of brain injury and hydromineral disorders, cytotoxic and osmotic cerebral edemas are the most common pathological manifestation. Hyponatremia is the most common cause of osmotic cerebral edema. Overly fast correction of hyponatremia could lead to central pontine myelinolysis. Ischemic stroke exemplifies cytotoxic cerebral edema. In this review, we summarize and analyze the osmosensory functions of astrocytes and their implications in cerebral edema.
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Affiliation(s)
- Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, United States
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Abstract
Patients with severe (serum sodium ≤120 mEq/L), symptomatic hyponatremia can develop life-threatening or fatal complications from cerebral edema if treatment is inadequate and permanent neurologic disability from osmotic demyelination if treatment is excessive. Unfortunately, as is true of all electrolyte disturbances, there are no randomized trials to guide the treatment of this challenging disorder. Rather, therapeutic decisions rest on physiologic principles, animal models, observational studies, and single-patient reports. European guidelines and recommendations of an American Expert panel have come to similar conclusions on how much correction of hyponatremia is enough and how much is too much, but there are important differences. We review the evidence supporting these recommendations, identifying areas that rest on relatively solid ground and highlighting areas in greatest need of additional data.
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Affiliation(s)
- Richard H Sterns
- University of Rochester School of Medicine and Dentistry, Rochester General Hospital, Rochester, New York
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31
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Decaux G, Gankam Kengne F, Couturier B, Musch W, Soupart A, Vandergheynst F. Mild water restriction with or without urea for the longterm treatment of syndrome of inappropriate antidiuretic hormone secretion (SIADH): Can urine osmolality help the choice? Eur J Intern Med 2018; 48:89-93. [PMID: 29017746 DOI: 10.1016/j.ejim.2017.09.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/20/2017] [Accepted: 09/22/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Treatment options for chronic SIADH include water restriction (WR) and urea. The usefulness of urine osmolality to guide the choice of the treatment option is not clearly defined. We hypothesized that urine osmolality can indicate whether treatment with mild water restriction alone could be successful. METHODS Retrospective Review of clinical and biochemical (blood and urine) data of patients with chronic SIADH treated for at least one year with mild WR (1.5-2l/day) either with or without urea. RESULTS Twenty nine patients were included. Nine patients were treated by mild WR. Mean serum sodium (SNa) and mean Uosm were 129±2mEq/l and 274±78mOsm/kgH2O respectively before WR, and increased to 138.5±3mEq/l and 505±87mOsm/kgH2O (P<0.001). Eight patients were treated with mild WR and 15g urea daily, the SNa and Uosm before treatment were 127.5±3mEq/l and 340±100mOsm/kgH2O respectively and increased to 136.5±1mEq/l and 490±151mOsm/kgH2O (P<0.001). Four of the eight patients had a permanent low solute intake which contributed to hyponatremia. Twelve patients needed 30g urea daily combined with mild WR. The SNa and Uosm were respectively 126±2mEq/l and 595±176mOsm/kgH2O and increased to 136.5±2mEq/l and 698±157mOsm/kgH2O (P<0.05). Uosm increased in most of the treated patients. CONCLUSIONS About 30% of patients could be treated by moderate WR alone. All these patients presented an initial urine osmolality lower than 400mOsm/kgH2O.
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Affiliation(s)
- G Decaux
- Department of Internal Medicine, Cliniques Universitaires Erasme, Brussels, Belgium; Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium.
| | - F Gankam Kengne
- Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium
| | - B Couturier
- Department of Internal Medicine, Cliniques Universitaires Erasme, Brussels, Belgium; Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium
| | - W Musch
- Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium
| | - A Soupart
- Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium
| | - F Vandergheynst
- Department of Internal Medicine, Cliniques Universitaires Erasme, Brussels, Belgium; Research Unit on Hydromineral Metabolism, Cliniques Universitaires Erasme, Brussels, Belgium
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Bouchat J, Couturier B, Marneffe C, Gankam-Kengne F, Balau B, De Swert K, Brion JP, Poncelet L, Gilloteaux J, Nicaise C. Regional oligodendrocytopathy and astrocytopathy precede myelin loss and blood-brain barrier disruption in a murine model of osmotic demyelination syndrome. Glia 2017; 66:606-622. [DOI: 10.1002/glia.23268] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/28/2022]
Affiliation(s)
| | - Bruno Couturier
- Department of General Medicine; Erasme Hospital, Université Libre de Bruxelles; Bruxelles Belgium
- Laboratory of Histology, Neuroanatomy and Neuropathology; Université Libre de Bruxelles; Bruxelles Belgium
| | | | - Fabrice Gankam-Kengne
- Laboratory of Histology, Neuroanatomy and Neuropathology; Université Libre de Bruxelles; Bruxelles Belgium
- Department of Nephrology; EpiCURA Ath; Ath Belgium
| | - Benoît Balau
- URPhyM - NARILIS, Université de Namur; Namur Belgium
| | | | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology; Université Libre de Bruxelles; Bruxelles Belgium
| | - Luc Poncelet
- Laboratory of Anatomy, Biomechanics and Organogenesis; Université Libre de Bruxelles; Bruxelles Belgium
| | - Jacques Gilloteaux
- URPhyM - NARILIS, Université de Namur; Namur Belgium
- Department of Anatomical Sciences; St George's University School of Medicine, Newcastle upon Tyne; United Kingdom
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Hyponatremia and the Brain. Kidney Int Rep 2017; 3:24-35. [PMID: 29340311 PMCID: PMC5762960 DOI: 10.1016/j.ekir.2017.08.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/23/2017] [Accepted: 08/28/2017] [Indexed: 01/12/2023] Open
Abstract
Hyponatremia is defined by low serum sodium concentration and is the most common electrolyte disorder encountered in clinical practice. Serum sodium is the main determinant of plasma osmolality, which, in turn, affects cell volume. In the presence of low extracellular osmolality, cells will swell if the adaptation mechanisms involved in the cell volume maintenance are inadequate. The most dramatic effects of hyponatremia on the brain are seen when serum sodium concentration decreases in a short period, allowing little or no adaptation. The brain is constrained inside a nonextensible envelope; thus, brain swelling carries a significant morbidity because of the compression of brain parenchyma over the rigid skull. Serum sodium concentration is an important determinant of several biological pathways in the nervous system, and recent studies have suggested that hyponatremia carries a significant risk of neurological impairment even in the absence of brain edema. The brain can also be affected by the treatment of hyponatremia, which, if not undertaken cautiously, could lead to osmotic demyelination syndrome, a rare demyelinating brain disorder that occurs after rapid correction of severe hyponatremia. This review summarizes the pathophysiology of brain complications of hyponatremia and its treatment.
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Peña-Oyarzun D, Troncoso R, Kretschmar C, Hernando C, Budini M, Morselli E, Lavandero S, Criollo A. Hyperosmotic stress stimulates autophagy via polycystin-2. Oncotarget 2017; 8:55984-55997. [PMID: 28915568 PMCID: PMC5593539 DOI: 10.18632/oncotarget.18995] [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] [Received: 05/10/2017] [Accepted: 06/21/2017] [Indexed: 12/13/2022] Open
Abstract
Various intracellular mechanisms are activated in response to stress, leading to adaptation or death. Autophagy, an intracellular process that promotes lysosomal degradation of proteins, is an adaptive response to several types of stress. Osmotic stress occurs under both physiological and pathological conditions, provoking mechanical stress and activating various osmoadaptive mechanisms. Polycystin-2 (PC2), a membrane protein of the polycystin family, is a mechanical sensor capable of activating the cell signaling pathways required for cell adaptation and survival. Here we show that hyperosmotic stress provoked by treatment with hyperosmolar concentrations of sorbitol or mannitol induces autophagy in HeLa and HCT116 cell lines. In addition, we show that mTOR and AMPK, two stress sensor proteins involved modulating autophagy, are downregulated and upregulated, respectively, when cells are subjected to hyperosmotic stress. Finally, our findings show that PC2 is required to promote hyperosmotic stress-induced autophagy. Downregulation of PC2 prevents inhibition of hyperosmotic stress-induced mTOR pathway activation. In conclusion, our data provide new insight into the role of PC2 as a mechanosensor that modulates autophagy under hyperosmotic stress conditions.
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Affiliation(s)
- Daniel Peña-Oyarzun
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Rodrigo Troncoso
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Catalina Kretschmar
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Cecilia Hernando
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Mauricio Budini
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Eugenia Morselli
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Department of Internal Medicine (Cardiology Division), University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alfredo Criollo
- Advanced Center for Chronic Diseases, Facultad Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
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