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Schneider A, Won S, Armstrong EA, Cooper AJ, Suresh A, Rivera R, Barrett-Wilt G, Denu JM, Simcox JA, Svaren J. The role of ATP citrate lyase in myelin formation and maintenance. Glia 2024. [PMID: 39318247 DOI: 10.1002/glia.24620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 09/05/2024] [Accepted: 09/14/2024] [Indexed: 09/26/2024]
Abstract
Formation of myelin by Schwann cells is tightly coupled to peripheral nervous system development and is important for neuronal function and long-term maintenance. Perturbation of myelin causes a number of specific disorders that are among the most prevalent diseases affecting the nervous system. Schwann cells synthesize myelin lipids de novo rather than relying on uptake of circulating lipids, yet one unresolved matter is how acetyl CoA, a central metabolite in lipid formation is generated during myelin formation and maintenance. Recent studies have shown that glucose-derived acetyl CoA itself is not required for myelination. However, the importance of mitochondrially-derived acetyl CoA has never been tested for myelination in vivo. Therefore, we have developed a Schwann cell-specific knockout of the ATP citrate lyase (Acly) gene to determine the importance of mitochondrial metabolism to supply acetyl CoA in nerve development. Intriguingly, the ACLY pathway is important for myelin maintenance rather than myelin formation. In addition, ACLY is required to maintain expression of a myelin-associated gene program and to inhibit activation of the latent Schwann cell injury program.
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Affiliation(s)
- Andrew Schneider
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Seongsik Won
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Eric A Armstrong
- Wisconsin Institute of Discovery, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aaron J Cooper
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amulya Suresh
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Rachell Rivera
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - John M Denu
- Wisconsin Institute of Discovery, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Judith A Simcox
- Howard Hughes Medical Institute, Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Preeti K, Sood A, Fernandes V, Khan I, Khatri DK, Singh SB. Experimental Type 2 diabetes and lipotoxicity-associated neuroinflammation involve mitochondrial DNA-mediated cGAS/STING axis: implication of Type-1 interferon response in cognitive impairment. Mol Neurobiol 2024; 61:6217-6244. [PMID: 38285288 DOI: 10.1007/s12035-024-03933-y] [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: 09/08/2023] [Accepted: 01/05/2024] [Indexed: 01/30/2024]
Abstract
Type-1 IFN (interferon)-associated innate immune response is increasingly getting attention in neurodegenerative and metabolic diseases like type 2 diabetes (T2DM). However, its significance in T2DM/lipotoxicity-induced neuroglia changes and cognitive impairment is missing. The present study aims to evaluate the involvement of cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon gene), IRF3 (interferon regulatory factor-3), TBK (TANK binding kinase)-mediated Type-1 IFN response in the diabetic brain, and lipotoxicity (palmitate-bovine serum albumin conjugate/PA-BSA)-induced changes in cells (neuro2a and BV2). T2DM was induced in C57/BL6 mice by feeding on a high-fat diet (HFD, 60% Kcal) for 16 weeks and injecting a single dose of streptozotocin (100 mg/kg, i.p) in the 12th week. Plasma biochemical parameter analysis, neurobehavioral assessment, protein expression, and quantitative polymerase chain reaction study were carried out to decipher the hypothesis. T2DM-associated metabolic and lipotoxic stress led to mitochondrial impairment causing leakage of mtDNA to the cytoplasm further commencing cGAS activation and its downstream signaling. The diseased hippocampus and cortex showed decreased expression of synaptophysin (p < 0.01) and PSD-95 (p < 0.01, p < 0.05) with increased expression of cGAS (p < 0.001), p-STING (p < 0.001), p-STAT1 (signal transducer and activator of transcription) (p < 0.01), and IFN-β (p < 0.001) compared to normal control. The IFN-β/p-STAT1-mediated microglia activation was executed employing a conditioned media approach. C-176, a selective STING inhibitor, alleviated cGAS/p-STING/IFN-β expression and proinflammatory microglia/M1-associated markers (CD16 expression, CXCL10, TNF-α, IL-1β mRNA fold change) in the diabetic brain. The present study suggests Type-1IFN response may result in neuroglia dyshomeostasis affecting normal brain function. Alleviating STING signaling has the potential to protect T2DM-associated central ailment.
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Affiliation(s)
- Kumari Preeti
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Anika Sood
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Valencia Fernandes
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Islauddin Khan
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Dharmendra Kumar Khatri
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India.
- Department of Pharmacology, Shobhaben Pratapbai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies (NMIMS) Deemed-to-University, Mumbai, 400056, India.
| | - Shashi Bala Singh
- Molecular & Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India.
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India.
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Bame X, Hill RA. Mitochondrial network reorganization and transient expansion during oligodendrocyte generation. Nat Commun 2024; 15:6979. [PMID: 39143079 PMCID: PMC11324877 DOI: 10.1038/s41467-024-51016-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 07/24/2024] [Indexed: 08/16/2024] Open
Abstract
Oligodendrocyte precursor cells (OPCs) give rise to myelinating oligodendrocytes of the brain. This process persists throughout life and is essential for recovery from neurodegeneration. To better understand the cellular checkpoints that occur during oligodendrogenesis, we determined the mitochondrial distribution and morphometrics across the oligodendrocyte lineage in mouse and human cerebral cortex. During oligodendrocyte generation, mitochondrial content expands concurrently with a change in subcellular partitioning towards the distal processes. These changes are followed by an abrupt loss of mitochondria in the oligodendrocyte processes and myelin, coinciding with sheath compaction. This reorganization and extensive expansion and depletion take 3 days. Oligodendrocyte mitochondria are stationary over days while OPC mitochondrial motility is modulated by animal arousal state within minutes. Aged OPCs also display decreased mitochondrial size, volume fraction, and motility. Thus, mitochondrial dynamics are linked to oligodendrocyte generation, dynamically modified by their local microenvironment, and altered in the aging brain.
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Affiliation(s)
- Xhoela Bame
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Robert A Hill
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA.
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Brask-Thomsen PK, Itani M, Karlsson P, Kristensen AG, Krøigård T, Jensen TS, Tankisi H, Sindrup SH, Finnerup NB, Gylfadottir SS. Development and Progression of Polyneuropathy Over 5 Years in Patients With Type 2 Diabetes. Neurology 2024; 103:e209652. [PMID: 39008800 DOI: 10.1212/wnl.0000000000209652] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND AND OBJECTIVES There is a need for knowledge regarding the natural course of diabetic polyneuropathy (DPN), a complication in type 2 diabetes (T2D). The aim of this study was to examine the development of DPN over time. METHODS Patients with newly diagnosed T2D, recruited from a national cohort, and controls without diabetes of similar age and sex, underwent sensory phenotyping in 2016-2018. The Toronto consensus criteria were used to classify patients into possible, probable, and confirmed DPN. For this 5-year, observational, follow-up, cohort study, all participants were invited to a reexamination combining bedside sensory examination, quantitative sensory testing (QST), nerve conduction studies (NCSs), and skin biopsies measuring intraepidermal nerve fiber density (IENFD) in order to compare phenotypic and diagnostic changes over time. RESULTS Of the baseline 389 patients and 97 controls, 184 patients (median [interquartile range] diabetes duration 5.9 [4.1-7.4] years, mean hemoglobin A1c [HbA1c] 51 ± 11 mmol/mol at baseline) and 43 controls completed follow-up (46.9%). Confirmed DPN was present in 35.8% and 50.3%, probable DPN in 27.2% and 14.6%, possible DPN in 17.2% and 16.6%, and no DPN in 15.2% and 17.9% at baseline and follow-up, respectively. The estimated prevalence (95% CI) of confirmed DPN was 33.5% (24.9-42.1) compared with 22.7% (17.5-28.0) at baseline. During the follow-up period, 43.9% of patients with probable DPN developed confirmed DPN. Progression of neuropathy occurred in 16.5% and 24.7% and regression in 5.9% and 18.6% of patients based on NCS and IENFD, respectively. Progression based on NCS and/or IENFD was associated with higher baseline waist circumference and triglycerides, and regression with lower baseline HbA1c. Patients with at least probable DPN at baseline but neither patients without DPN nor controls developed increased spread of hyposensitivity, more hyposensitivity on QST and lower NCS z-scores at follow-up, and worsening of nerve parameters at follow-up correlated with higher baseline triglycerides. DISCUSSION In patients with well-regulated T2D, the proportion of patients with confirmed DPN increased over 5 years driven by progression from probable DPN. A large proportion of patients progressed, and a smaller proportion regressed on nerve parameters. Higher triglycerides correlated with this progression and may constitute a risk factor.
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Affiliation(s)
- Peter Kolind Brask-Thomsen
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Mustapha Itani
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Pall Karlsson
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Alexander G Kristensen
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Thomas Krøigård
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Troels S Jensen
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Hatice Tankisi
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Søren H Sindrup
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Nanna B Finnerup
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
| | - Sandra Sif Gylfadottir
- From the Danish Pain Research Center (P.K.B.-T., P.K., A.G.K., T.S.J., N.B.F., S.S.G.), Department of Clinical Medicine, Aarhus University; Steno Diabetes Center Aarhus (P.K.B.-T., T.S.J.), Aarhus University Hospital; Department of Neurology (M.I., T.K., S.H.S.), Odense University Hospital; Core Center for Molecular Morphology (P.K.), Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University; Department of Clinical Neurophysiology (A.G.K., H.T.), Aarhus University Hospital; Department of Neurophysiology (T.K.), Odense University Hospital; Department of Clinical Research (T.K.), University of Southern Denmark, Odense; Department of Clinical Medicine (H.T.), Aarhus University; and Department of Neurology (N.B.F., S.S.G.), Aarhus University Hospital, Denmark
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Wu L, Wang XJ, Luo X, Zhang J, Zhao X, Chen Q. Diabetic peripheral neuropathy based on Schwann cell injury: mechanisms of cell death regulation and therapeutic perspectives. Front Endocrinol (Lausanne) 2024; 15:1427679. [PMID: 39193373 PMCID: PMC11348392 DOI: 10.3389/fendo.2024.1427679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/24/2024] [Indexed: 08/29/2024] Open
Abstract
Diabetic peripheral neuropathy (DPN) is a complication of diabetes mellitus that lacks specific treatment, its high prevalence and disabling neuropathic pain greatly affects patients' physical and mental health. Schwann cells (SCs) are the major glial cells of the peripheral nervous system, which play an important role in various inflammatory and metabolic neuropathies by providing nutritional support, wrapping axons and promoting repair and regeneration. Increasingly, high glucose (HG) has been found to promote the progression of DPN pathogenesis by targeting SCs death regulation, thus revealing the specific molecular process of programmed cell death (PCD) in which SCs are disrupted is an important link to gain insight into the pathogenesis of DPN. This paper is the first to review the recent progress of HG studies on apoptosis, autophagy, pyroptosis, ferroptosis and necroptosis pathways in SCs, and points out the crosstalk between various PCDs and the related therapeutic perspectives, with the aim of providing new perspectives for a deeper understanding of the mechanisms of DPN and the exploration of effective therapeutic targets.
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Affiliation(s)
- Lijiao Wu
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiang Jin Wang
- School of Sports Medicine and Health, Chengdu Sports University, Chengdu, China
| | - Xi Luo
- Jiangsu Key Laboratory for Functional Substance of Chinese Medicine, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jingqi Zhang
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xinyi Zhao
- College of lntegrated Traditional Chinese and Western Medicine, Hunan University of Chinese Medicine, Hunan, China
| | - Qiu Chen
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
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6
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Mishra SK, Tiwari SP. Bioenergetics of Axon Integrity and Its Regulation by Oligodendrocytes and Schwann Cells. Mol Neurobiol 2024; 61:5928-5934. [PMID: 38252382 DOI: 10.1007/s12035-024-03950-x] [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: 05/25/2023] [Accepted: 01/09/2024] [Indexed: 01/23/2024]
Abstract
Axons are long slender portions of neurons that transmit electrical impulses to maintain proper physiological functioning. Axons in the central nervous system (CNS) and peripheral nervous system (PNS) do not exist in isolation but are found to form a complex association with their surrounding glial cells, oligodendrocytes and Schwann cells. These cells not only myelinate them for faster nerve impulse conduction but are also known to provide metabolic support. Due to their incredible length, continuous growth, and distance from the cell body (where major energy synthesis takes place), axons are in high energetic demand. The stability and integrity of axons have long been associated with axonal energy levels. The current mini-review is thus focused on how axons accomplish their high energetic requirement in a cell-autonomous manner and how the surrounding glial cells help them in maintaining their integrity by fulfilling their energy demands (non-cell autonomous trophic support). The concept that adjacent glial cells (oligodendrocytes and Schwann cells) provide trophic support to axons and assist them in maintaining their integrity comes from the conditional knockout research and the studies in which the metabolic pathways controlling metabolism in these glial cells are modulated and its effect on axonal integrity is evaluated. In the later part of the mini-review, the current knowledge of axon-glial metabolic coupling during various neurodegenerative conditions was discussed, along with the potential lacunae in our current understanding of axon-glial metabolic coupling.
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Affiliation(s)
- Sandeep K Mishra
- Institute for Myelin and Glia Exploration, University at Buffalo, Buffalo, NY, 14203, USA.
- Faculty of Pharmacy, Kalinga University, Raipur, (C.G.), 492101, India.
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7
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Ratan Y, Rajput A, Pareek A, Pareek A, Kaur R, Sonia S, Kumar R, Singh G. Recent Advances in Biomolecular Patho-Mechanistic Pathways behind the Development and Progression of Diabetic Neuropathy. Biomedicines 2024; 12:1390. [PMID: 39061964 PMCID: PMC11273858 DOI: 10.3390/biomedicines12071390] [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: 05/07/2024] [Revised: 06/12/2024] [Accepted: 06/19/2024] [Indexed: 07/28/2024] Open
Abstract
Diabetic neuropathy (DN) is a neurodegenerative disorder that is primarily characterized by distal sensory loss, reduced mobility, and foot ulcers that may potentially lead to amputation. The multifaceted etiology of DN is linked to a range of inflammatory, vascular, metabolic, and other neurodegenerative factors. Chronic inflammation, endothelial dysfunction, and oxidative stress are the three basic biological changes that contribute to the development of DN. Although our understanding of the intricacies of DN has advanced significantly over the past decade, the distinctive mechanisms underlying the condition are still poorly understood, which may be the reason behind the lack of an effective treatment and cure for DN. The present study delivers a comprehensive understanding and highlights the potential role of the several pathways and molecular mechanisms underlying the etiopathogenesis of DN. Moreover, Schwann cells and satellite glial cells, as integral factors in the pathogenesis of DN, have been enlightened. This work will motivate allied research disciplines to gain a better understanding and analysis of the current state of the biomolecular mechanisms behind the pathogenesis of DN, which will be essential to effectively address every facet of DN, from prevention to treatment.
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Affiliation(s)
- Yashumati Ratan
- Department of Pharmacy, Banasthali Vidyapith, Banasthali 304022, Rajasthan, India; (A.R.); (A.P.); (A.P.)
| | - Aishwarya Rajput
- Department of Pharmacy, Banasthali Vidyapith, Banasthali 304022, Rajasthan, India; (A.R.); (A.P.); (A.P.)
| | - Ashutosh Pareek
- Department of Pharmacy, Banasthali Vidyapith, Banasthali 304022, Rajasthan, India; (A.R.); (A.P.); (A.P.)
| | - Aaushi Pareek
- Department of Pharmacy, Banasthali Vidyapith, Banasthali 304022, Rajasthan, India; (A.R.); (A.P.); (A.P.)
| | - Ranjeet Kaur
- Adesh Institute of Dental Sciences and Research, Bathinda 151101, Punjab, India;
| | - Sonia Sonia
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar 143005, Punjab, India;
| | - Rahul Kumar
- Baba Ragav Das Government Medical College, Gorakhpur 273013, Uttar Pradesh, India;
| | - Gurjit Singh
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
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8
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Hong J, Garfolo R, Kabre S, Humml C, Velanac V, Roué C, Beck B, Jeanette H, Haslam S, Bach M, Arora S, Acheta J, Nave KA, Schwab MH, Jourd’heuil D, Poitelon Y, Belin S. PMP2 regulates myelin thickening and ATP production during remyelination. Glia 2024; 72:885-898. [PMID: 38311982 PMCID: PMC11027087 DOI: 10.1002/glia.24508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/22/2023] [Accepted: 01/16/2024] [Indexed: 02/06/2024]
Abstract
It is well established that axonal Neuregulin 1 type 3 (NRG1t3) regulates developmental myelin formation as well as EGR2-dependent gene activation and lipid synthesis. However, in peripheral neuropathy disease context, elevated axonal NRG1t3 improves remyelination and myelin sheath thickness without increasing Egr2 expression or activity, and without affecting the transcriptional activity of canonical myelination genes. Surprisingly, Pmp2, encoding for a myelin fatty acid binding protein, is the only gene whose expression increases in Schwann cells following overexpression of axonal NRG1t3. Here, we demonstrate PMP2 expression is directly regulated by NRG1t3 active form, following proteolytic cleavage. Then, using a transgenic mouse model overexpressing axonal NRG1t3 (NRG1t3OE) and knocked out for PMP2, we demonstrate that PMP2 is required for NRG1t3-mediated remyelination. We demonstrate that the sustained expression of Pmp2 in NRG1t3OE mice enhances the fatty acid uptake in sciatic nerve fibers and the mitochondrial ATP production in Schwann cells. In sum, our findings demonstrate that PMP2 is a direct downstream mediator of NRG1t3 and that the modulation of PMP2 downstream NRG1t3 activation has distinct effects on Schwann cell function during developmental myelination and remyelination.
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Affiliation(s)
- Jiayue Hong
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Rebekah Garfolo
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Sejal Kabre
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Christian Humml
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Viktorija Velanac
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Clémence Roué
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Brianna Beck
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Haley Jeanette
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Sarah Haslam
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Martin Bach
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Simar Arora
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Jenica Acheta
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Markus H. Schwab
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Paul Flechsig Institute of Neuropathology, University Hospital Leipzig, Leipzig, Germany
| | - David Jourd’heuil
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, USA
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Sophie Belin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
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9
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Ryoo HD. The integrated stress response in metabolic adaptation. J Biol Chem 2024; 300:107151. [PMID: 38462161 PMCID: PMC10998230 DOI: 10.1016/j.jbc.2024.107151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/28/2024] [Accepted: 03/03/2024] [Indexed: 03/12/2024] Open
Abstract
The integrated stress response (ISR) refers to signaling pathways initiated by stress-activated eIF2α kinases. Distinct eIF2α kinases respond to different stress signals, including amino acid deprivation and mitochondrial stress. Such stress-induced eIF2α phosphorylation attenuates general mRNA translation and, at the same time, stimulates the preferential translation of specific downstream factors to orchestrate an adaptive gene expression program. In recent years, there have been significant new advances in our understanding of ISR during metabolic stress adaptation. Here, I discuss those advances, reviewing among others the ISR activation mechanisms in response to amino acid deprivation and mitochondrial stress. In addition, I review how ISR regulates the amino acid metabolic pathways and how changes in the ISR impact the physiology and pathology of various disease models.
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Affiliation(s)
- Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA.
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10
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Dhanapalaratnam R, Issar T, Poynten AM, Milner KL, Kwai NCG, Krishnan AV. Progression of axonal excitability abnormalities with increasing clinical severity of diabetic peripheral neuropathy. Clin Neurophysiol 2024; 160:12-18. [PMID: 38367309 DOI: 10.1016/j.clinph.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/18/2024] [Accepted: 02/05/2024] [Indexed: 02/19/2024]
Abstract
OBJECTIVE Diabetic peripheral neuropathy (DPN) is a frequent complication for persons with type 2 diabetes. Previous studies have failed to demonstrate any significant impact of treatment for DPN. The present study assessed the role of axonal ion channel dysfunction in DPN and explored the hypothesis that there may be a progressive change in ion channel abnormalities that varied with disease stage. METHODS Neurophysiological studies were conducted using axonal excitability techniques, a clinical method of assessing ion channel dysfunction. Studies were conducted in 178 persons with type 2 diabetes, with participants allocated into four groups according to clinical severity of neuropathy, assessed using the Total Neuropathy Grade. RESULTS Analysis of excitability data demonstrated a progressive and stepwise reduction in two parameters that are related to the activity of Kv1.1 channels, namely superexcitability and depolarizing threshold electrotonus at 10-20 ms (p < 0.001), and mathematical modelling of axonal excitability findings supported progressive upregulation of Kv1.1 conductances with increasing greater disease severity. CONCLUSION The findings are consistent with a progressive upregulation of juxtaparanodal Kv1.1 conductances with increasing clinical severity of diabetic peripheral neuropathy. SIGNIFICANCE From a translational perspective, the study suggests that blockade of Kv1.1 channels using 4-aminopyridine derivatives such as fampridine may be a potential treatment for DPN.
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Affiliation(s)
- Roshan Dhanapalaratnam
- School of Clinical Medicine, UNSW Sydney, NSW 2031, Australia; Department of Neurology, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Tushar Issar
- School of Clinical Medicine, UNSW Sydney, NSW 2031, Australia
| | - Ann M Poynten
- School of Clinical Medicine, UNSW Sydney, NSW 2031, Australia; Department of Endocrinology, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Kerry-Lee Milner
- School of Clinical Medicine, UNSW Sydney, NSW 2031, Australia; Department of Endocrinology, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Natalie C G Kwai
- School of Medical, Indigenous and Health Sciences, University of Wollongong, Australia
| | - Arun V Krishnan
- School of Clinical Medicine, UNSW Sydney, NSW 2031, Australia; Department of Neurology, Prince of Wales Hospital, Sydney, NSW 2031, Australia.
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11
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Trimarco A, Audano M, Marca RL, Cariello M, Falco M, Pedretti S, Imperato G, Cestaro A, Podini P, Dina G, Quattrini A, Massimino L, Caruso D, Mitro N, Taveggia C. Prostaglandin D2 synthase controls Schwann cells metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582775. [PMID: 38496560 PMCID: PMC10942270 DOI: 10.1101/2024.02.29.582775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
We previously reported that in the absence of Prostaglandin D2 synthase (L-PGDS) peripheral nerves are hypomyelinated in development and that with aging they present aberrant myelin sheaths. We now demonstrate that L-PGDS expressed in Schwann cells is part of a coordinated program aiming at preserving myelin integrity. In vivo and in vitro lipidomic, metabolomic and transcriptomic analyses confirmed that myelin lipids composition, Schwann cells energetic metabolism and key enzymes controlling these processes are altered in the absence of L-PGDS. Moreover, Schwann cells undergo a metabolic rewiring and turn to acetate as the main energetic source. Further, they produce ketone bodies to ensure glial cell and neuronal survival. Importantly, we demonstrate that all these changes correlate with morphological myelin alterations and describe the first physiological pathway implicated in preserving PNS myelin. Collectively, we posit that myelin lipids serve as a reservoir to provide ketone bodies, which together with acetate represent the adaptive substrates Schwann cells can rely on to sustain the axo-glial unit and preserve the integrity of the PNS.
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12
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Podmanicky O, Gao F, Munro B, Jennings MJ, Boczonadi V, Hathazi D, Mueller JS, Horvath R. Mitochondrial aminoacyl-tRNA synthetases trigger unique compensatory mechanisms in neurons. Hum Mol Genet 2024; 33:435-447. [PMID: 37975900 PMCID: PMC10877469 DOI: 10.1093/hmg/ddad196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/05/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Abstract
Mitochondrial aminoacyl-tRNA synthetase (mt-ARS) mutations cause severe, progressive, and often lethal diseases with highly heterogeneous and tissue-specific clinical manifestations. This study investigates the molecular mechanisms triggered by three different mt-ARS defects caused by biallelic mutations in AARS2, EARS2, and RARS2, using an in vitro model of human neuronal cells. We report distinct molecular mechanisms of mitochondrial dysfunction among the mt-ARS defects studied. Our findings highlight the ability of proliferating neuronal progenitor cells (iNPCs) to compensate for mitochondrial translation defects and maintain balanced levels of oxidative phosphorylation (OXPHOS) components, which becomes more challenging in mature neurons. Mutant iNPCs exhibit unique compensatory mechanisms, involving specific branches of the integrated stress response, which may be gene-specific or related to the severity of the mitochondrial translation defect. RNA sequencing revealed distinct transcriptomic profiles showing dysregulation of neuronal differentiation and protein translation. This study provides valuable insights into the tissue-specific compensatory mechanisms potentially underlying the phenotypes of patients with mt-ARS defects. Our novel in vitro model may more accurately represent the neurological presentation of patients and offer an improved platform for future investigations and therapeutic development.
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Affiliation(s)
- Oliver Podmanicky
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Fei Gao
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Benjamin Munro
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Matthew J Jennings
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
- Department of Neurology, Columbia University, 630 West 168 St, New York, NY 10032, United States
| | - Veronika Boczonadi
- Biosciences Institute, International Centre for Life, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Denisa Hathazi
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Juliane S Mueller
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
- Dubowitz Neuromuscular Centre, Department of Neuropathology, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom
| | - Rita Horvath
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
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13
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André-Lévigne D, Pignel R, Boet S, Jaquet V, Kalbermatten DF, Madduri S. Role of Oxygen and Its Radicals in Peripheral Nerve Regeneration: From Hypoxia to Physoxia to Hyperoxia. Int J Mol Sci 2024; 25:2030. [PMID: 38396709 PMCID: PMC10888612 DOI: 10.3390/ijms25042030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Oxygen is compulsory for mitochondrial function and energy supply, but it has numerous more nuanced roles. The different roles of oxygen in peripheral nerve regeneration range from energy supply, inflammation, phagocytosis, and oxidative cell destruction in the context of reperfusion injury to crucial redox signaling cascades that are necessary for effective axonal outgrowth. A fine balance between reactive oxygen species production and antioxidant activity draws the line between physiological and pathological nerve regeneration. There is compelling evidence that redox signaling mediated by the Nox family of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases plays an important role in peripheral nerve regeneration. Further research is needed to better characterize the role of Nox in physiological and pathological circumstances, but the available data suggest that the modulation of Nox activity fosters great therapeutic potential. One of the promising approaches to enhance nerve regeneration by modulating the redox environment is hyperbaric oxygen therapy. In this review, we highlight the influence of various oxygenation states, i.e., hypoxia, physoxia, and hyperoxia, on peripheral nerve repair and regeneration. We summarize the currently available data and knowledge on the effectiveness of using hyperbaric oxygen therapy to treat nerve injuries and discuss future directions.
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Affiliation(s)
- Dominik André-Lévigne
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
| | - Rodrigue Pignel
- Subaquatic and Hyperbaric Medicine Unit, Division of Emergency Medicine, Department of Anesthesiology, Clinical Pharmacology, Intensive Care and Emergency Medicine, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | - Sylvain Boet
- Subaquatic and Hyperbaric Medicine Unit, Division of Emergency Medicine, Department of Anesthesiology, Clinical Pharmacology, Intensive Care and Emergency Medicine, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
- Department of Anesthesiology and Pain Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
- Ottawa Hospital Research Institute, Clinical Epidemiology Program, Department of Innovation in Medical Education, University of Ottawa, Ottawa, ON K1H 8L6, Canada
- Institut du Savoir Montfort, Ottawa, ON K1K 0T2, Canada
| | - Vincent Jaquet
- Department of Cell Physiology and Metabolism, University of Geneva, 1205 Geneva, Switzerland
- READS Unit, Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | - Daniel F. Kalbermatten
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
- Bioengineering and Neuroregeneration Laboratory, Department of Surgery, University of Geneva, 1205 Geneva, Switzerland
| | - Srinivas Madduri
- Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, 1205 Geneva, Switzerland
- Bioengineering and Neuroregeneration Laboratory, Department of Surgery, University of Geneva, 1205 Geneva, Switzerland
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14
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De Lima S, Mietto BS, Ribas VT, Ribeiro-Resende VT, Oliveira ALR, Park KK. Editorial: Promoting nervous system regeneration by treatments targeting neuron-glia interactions. Front Cell Neurosci 2024; 17:1355469. [PMID: 38273976 PMCID: PMC10808721 DOI: 10.3389/fncel.2023.1355469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Affiliation(s)
- Silmara De Lima
- Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
- Department of Molecular and Cellular Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA, United States
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Bruno Siqueira Mietto
- Department of Biology, Institute of Biomedical Science, Juiz de Fora Federal University, Juiz de Fora, Minas Gerais, Brazil
| | - Vinicius Toledo Ribas
- Morphology Department, Institute of Biomedical Science, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Kevin K. Park
- Department of Ophthalmology and Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, United States
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15
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Bame X, Hill RA. Mitochondrial network reorganization and transient expansion during oligodendrocyte generation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570104. [PMID: 38106204 PMCID: PMC10723275 DOI: 10.1101/2023.12.05.570104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Oligodendrocyte precursor cells (OPCs) give rise to myelinating oligodendrocytes of the central nervous system. This process persists throughout life and is essential for recovery from neurodegeneration. To better understand the cellular checkpoints that occur during oligodendrogenesis, we determined the mitochondrial distribution and morphometrics across the oligodendrocyte lineage in mouse and human cerebral cortex. During oligodendrocyte generation, mitochondrial content expanded concurrently with a change in subcellular partitioning towards the distal processes. These changes were followed by an abrupt loss of mitochondria in the oligodendrocyte processes and myelin, coinciding with sheath compaction. This reorganization and extensive expansion and depletion took 3 days. Oligodendrocyte mitochondria were stationary over days while OPC mitochondrial motility was modulated by animal arousal state within minutes. Aged OPCs also displayed decreased mitochondrial size, content, and motility. Thus, mitochondrial dynamics are linked to oligodendrocyte generation, dynamically modified by their local microenvironment, and altered in the aging brain.
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Affiliation(s)
- Xhoela Bame
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Robert A Hill
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
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16
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Fan B, Chopp M, Zhang Y, Wang X, Kemper A, Zhang ZG, Liu XS. Ablation of Argonaute 2 in Schwann cells accelerates the progression of diabetic peripheral neuropathy. Glia 2023; 71:2196-2209. [PMID: 37178056 PMCID: PMC11057225 DOI: 10.1002/glia.24387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 04/25/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023]
Abstract
Schwann cells (SCs) form myelin and provide metabolic support for axons, and are essential for normal nerve function. Identification of key molecules specific to SCs and nerve fibers may provide new therapeutic targets for diabetic peripheral neuropathy (DPN). Argonaute2 (Ago2) is a key molecular player that mediates the activity of miRNA-guided mRNA cleavage and miRNA stability. Our study found that Ago2 knockout (Ago2-KO) in proteolipid protein (PLP) lineage SCs in mice resulted in a significant reduction of nerve conduction velocities and impairments of thermal and mechanical sensitivities. Histopathological data revealed that Ago2-KO significantly induced demyelination and neurodegeneration. When DPN was induced in both wild-type and Ago2-KO mice, Ago2-KO mice exhibited further decreased myelin thickness and exacerbated neurological outcomes compared with wild-type mice. Deep sequencing analysis of Ago2 immunoprecipitated complexes showed that deregulated miR-206 in Ago2-KO mice is highly related to mitochondrial function. In vitro data showed that knockdown of miR-200 induced mitochondrial dysfunction and apoptosis in SCs. Together, our data suggest that Ago2 in SCs is essential to maintain peripheral nerve function while ablation of Ago2 in SCs exacerbates SC dysfunction and neuronal degeneration in DPN. These findings provide new insight into the molecular mechanisms of DPN.
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Affiliation(s)
- Baoyan Fan
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
| | - Yi Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Xinli Wang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Amy Kemper
- Department of Pathology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
| | - Xian Shuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
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17
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Li L, Long J, Mise K, Poungavrin N, Lorenzi PL, Mahmud I, Tan L, Saha PK, Kanwar YS, Chang BH, Danesh FR. The transcription factor ChREBP links mitochondrial lipidomes to mitochondrial morphology and progression of diabetic kidney disease. J Biol Chem 2023; 299:105185. [PMID: 37611830 PMCID: PMC10506103 DOI: 10.1016/j.jbc.2023.105185] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/27/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023] Open
Abstract
A substantial body of evidence has established the contributions of both mitochondrial dynamics and lipid metabolism to the pathogenesis of diabetic kidney disease (DKD). However, the precise interplay between these two key metabolic regulators of DKD is not fully understood. Here, we uncover a link between mitochondrial dynamics and lipid metabolism by investigating the role of carbohydrate-response element-binding protein (ChREBP), a glucose-responsive transcription factor and a master regulator of lipogenesis, in kidney podocytes. We find that inducible podocyte-specific knockdown of ChREBP in diabetic db/db mice improves key biochemical and histological features of DKD in addition to significantly reducing mitochondrial fragmentation. Because of the critical role of ChREBP in lipid metabolism, we interrogated whether and how mitochondrial lipidomes play a role in ChREBP-mediated mitochondrial fission. Our findings suggest a key role for a family of ether phospholipids in ChREBP-induced mitochondrial remodeling. We find that overexpression of glyceronephosphate O-acyltransferase, a critical enzyme in the biosynthesis of plasmalogens, reverses the protective phenotype of ChREBP deficiency on mitochondrial fragmentation. Finally, our data also points to Gnpat as a direct transcriptional target of ChREBP. Taken together, our results uncover a distinct mitochondrial lipid signature as the link between ChREBP-induced mitochondrial dynamics and progression of DKD.
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Affiliation(s)
- Li Li
- Section of Nephrology, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jianyin Long
- Section of Nephrology, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Koki Mise
- Section of Nephrology, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Naravat Poungavrin
- Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Philip L Lorenzi
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Iqbal Mahmud
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Lin Tan
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Pradip K Saha
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Diabetes Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Yashpal S Kanwar
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Benny H Chang
- Section of Nephrology, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Farhad R Danesh
- Section of Nephrology, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA.
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18
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Eid SA, Noureldein M, Kim B, Hinder LM, Mendelson FE, Hayes JM, Hur J, Feldman EL. Single-cell RNA-seq uncovers novel metabolic functions of Schwann cells beyond myelination. J Neurochem 2023; 166:367-388. [PMID: 37328915 PMCID: PMC11141588 DOI: 10.1111/jnc.15877] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/04/2023] [Accepted: 05/30/2023] [Indexed: 06/18/2023]
Abstract
Schwann cells (SCs) support peripheral nerves under homeostatic conditions, independent of myelination, and contribute to damage in prediabetic peripheral neuropathy (PN). Here, we used single-cell RNA sequencing to characterize the transcriptional profiles and intercellular communication of SCs in the nerve microenvironment using the high-fat diet-fed mouse, which mimics human prediabetes and neuropathy. We identified four major SC clusters, myelinating, nonmyelinating, immature, and repair in healthy and neuropathic nerves, in addition to a distinct cluster of nerve macrophages. Myelinating SCs acquired a unique transcriptional profile, beyond myelination, in response to metabolic stress. Mapping SC intercellular communication identified a shift in communication, centered on immune response and trophic support pathways, which primarily impacted nonmyelinating SCs. Validation analyses revealed that neuropathic SCs become pro-inflammatory and insulin resistant under prediabetic conditions. Overall, our study offers a unique resource for interrogating SC function, communication, and signaling in nerve pathophysiology to help inform SC-specific therapies.
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Affiliation(s)
- Stéphanie A. Eid
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mohamed Noureldein
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Bhumsoo Kim
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lucy M. Hinder
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Faye E. Mendelson
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - John M. Hayes
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Junguk Hur
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA
| | - Eva L. Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
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19
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Storkebaum E, Rosenblum K, Sonenberg N. Messenger RNA Translation Defects in Neurodegenerative Diseases. Reply. N Engl J Med 2023; 388:2110-2111. [PMID: 37256994 DOI: 10.1056/nejmc2304387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
- Erik Storkebaum
- Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
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20
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Enders J, Elliott D, Wright DE. Emerging Nonpharmacologic Interventions to Treat Diabetic Peripheral Neuropathy. Antioxid Redox Signal 2023; 38:989-1000. [PMID: 36503268 PMCID: PMC10402707 DOI: 10.1089/ars.2022.0158] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/17/2022] [Accepted: 11/19/2022] [Indexed: 12/14/2022]
Abstract
Significance: Diabetic peripheral neuropathy (DPN), a complication of metabolic syndrome, type I and type II diabetes, leads to sensory changes that include slow nerve conduction, nerve degeneration, loss of sensation, pain, and gate disturbances. These complications remain largely untreatable, although tight glycemic control can prevent neuropathy progression. Nonpharmacologic approaches remain the most impactful to date, but additional advances in treatment approaches are needed. Recent Advances: This review highlights several emerging interventions, including a focus on dietary interventions and physical activity, that continue to show promise for treating DPN. We provide an overview of our current understanding of how exercise can improve aspects of DPN. We also highlight new studies in which a ketogenic diet has been used as an intervention to prevent and reverse DPN. Critical Issues: Both exercise and consuming a ketogenic diet induce systemic and cellular changes that collectively improve complications associated with DPN. Both interventions may involve similar signaling pathways and benefits but also impact DPN through unique mechanisms. Future Directions: These lifestyle interventions are critically important as personalized medicine approaches will likely be needed to identify specific subsets of neuropathy symptoms and deficits in patients, and determine the most impactful treatment. Overall, these two interventions have the potential to provide meaningful relief for patients with DPN and provide new avenues to identify new therapeutic targets.
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Affiliation(s)
- Jonathan Enders
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Daniel Elliott
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Douglas E. Wright
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
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21
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Deng H, Li B, Shen Q, Zhang C, Kuang L, Chen R, Wang S, Ma Z, Li G. Mechanisms of diabetic foot ulceration: A review. J Diabetes 2023; 15:299-312. [PMID: 36891783 PMCID: PMC10101842 DOI: 10.1111/1753-0407.13372] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/23/2023] [Accepted: 02/16/2023] [Indexed: 03/10/2023] Open
Abstract
Diabetic foot ulcers (DFUs) are associated with complex pathogenic factors and are considered a serious complication of diabetes. The potential mechanisms underlying DFUs have been increasingly investigated. Previous studies have focused on the three aspects of diabetic peripheral vascular disease, neuropathy, and wound infections. With advances in technology, researchers have been gradually conducting studies using immune cells, endothelial cells, keratinocytes, and fibroblasts, as they are involved in wound healing. It has been reported that the upregulation or downregulation of molecular signaling pathways is essential for the healing of DFUs. With a recent increase in the awareness of epigenetics, its regulatory role in wound healing has become a much sought-after trend in the treatment of DFUs. This review focuses on four aspects involved in the pathogenesis of DFUs: physiological and pathological mechanisms, cellular mechanisms, molecular signaling pathway mechanisms, and epigenetics. Given the challenge in the treatment of DFUs, we are hopeful that our review will provide new ideas for peers.
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Affiliation(s)
- Haibo Deng
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - Binghui Li
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - Qian Shen
- School of Foreign StudiesZhongnan University of Economics and LawWuhanHubeiChina
| | - Chenchen Zhang
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - Liwen Kuang
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - Ran Chen
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - SiYuan Wang
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - ZhiQiang Ma
- Department of Wound Repair, Liyuan Hospital Affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
| | - Gongchi Li
- Department of Hand Surgery, Union Hospital affiliated to Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina
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Buckman PJ, Scatton C, Cappola JJ. Peripheral Neuropathy Secondary to Ertapenem Administration for Treatment of Infectious Endocarditis. Cureus 2023; 15:e37253. [PMID: 37162774 PMCID: PMC10164356 DOI: 10.7759/cureus.37253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2023] [Indexed: 05/11/2023] Open
Abstract
Ertapenem is a widely used broad-spectrum carbapenem antibiotic active against most species of gram-negative and gram-positive aerobes and anaerobes with specific targeting of the Amp C extended-spectrum beta-lactamases. It is advantageous for its once-daily dosing via IM or IV administration and minimal side effect profile for the treatment of community-acquired infections. We report an 80-year-old man presenting with reversible peripheral neuropathy following the administration and subsequent discontinuation of ertapenem for the treatment of acute infectious endocarditis. It is especially notable that our patient had less severe (i.e., stage 3) chronic kidney disease as opposed to current literature which only presents similar findings with more advanced kidney disease (stage 4-5). Upon cessation of ertapenem administration, our patient recovered to his baseline motor and sensory status over a period of four days. We believe there to be value in reporting this case, as well as value in reevaluating the current recommendations for ertapenem dosing in those with kidney compromise.
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Affiliation(s)
- Patrick J Buckman
- Internal Medicine, Campbell University School of Osteopathic Medicine, Lillington, USA
| | | | - James J Cappola
- Internal Medicine, Campbell University School of Osteopathic Medicine, Lillington, USA
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23
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Marian OC, Teo JD, Lee JY, Song H, Kwok JB, Landin-Romero R, Halliday G, Don AS. Disrupted myelin lipid metabolism differentiates frontotemporal dementia caused by GRN and C9orf72 gene mutations. Acta Neuropathol Commun 2023; 11:52. [PMID: 36967384 PMCID: PMC10041703 DOI: 10.1186/s40478-023-01544-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 03/12/2023] [Indexed: 03/29/2023] Open
Abstract
Heterozygous mutations in the GRN gene and hexanucleotide repeat expansions in C9orf72 are the two most common genetic causes of Frontotemporal Dementia (FTD) with TDP-43 protein inclusions. The triggers for neurodegeneration in FTD with GRN (FTD-GRN) or C9orf72 (FTD-C9orf72) gene abnormalities are unknown, although evidence from mouse and cell culture models suggests that GRN mutations disrupt lysosomal lipid catabolism. To determine how brain lipid metabolism is affected in familial FTD with TDP-43 inclusions, and how this is related to myelin and lysosomal markers, we undertook comprehensive lipidomic analysis, enzyme activity assays, and western blotting on grey and white matter samples from the heavily-affected frontal lobe and less-affected parietal lobe of FTD-GRN cases, FTD-C9orf72 cases, and age-matched neurologically-normal controls. Substantial loss of myelin-enriched sphingolipids (sulfatide, galactosylceramide, sphingomyelin) and myelin proteins was observed in frontal white matter of FTD-GRN cases. A less-pronounced, yet statistically significant, loss of sphingolipids was also observed in FTD-C9orf72. FTD-GRN was distinguished from FTD-C9orf72 and control cases by increased acylcarnitines in frontal grey matter and marked accumulation of cholesterol esters in both frontal and parietal white matter, indicative of myelin break-down. Both FTD-GRN and FTD-C9orf72 cases showed significantly increased lysosomal and phagocytic protein markers, however galactocerebrosidase activity, required for lysosomal catabolism of galactosylceramide and sulfatide, was selectively increased in FTD-GRN. We conclude that both C9orf72 and GRN mutations are associated with disrupted lysosomal homeostasis and white matter lipid loss, but GRN mutations cause a more pronounced disruption to myelin lipid metabolism. Our findings support the hypothesis that hyperactive myelin lipid catabolism is a driver of gliosis and neurodegeneration in FTD-GRN. Since FTD-GRN is associated with white matter hyperintensities by MRI, our data provides important biochemical evidence supporting the use of MRI measures of white matter integrity in the diagnosis and management of FTD.
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Affiliation(s)
- Oana C Marian
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Jonathan D Teo
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Jun Yup Lee
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Huitong Song
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - John B Kwok
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
- Brain and Mind Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Ramon Landin-Romero
- Brain and Mind Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
- School of Health Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Glenda Halliday
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia
- Brain and Mind Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Anthony S Don
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, 2006, Australia.
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, 2006, Australia.
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24
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Cunningham ME, McGonigal R, Barrie JA, Campbell CI, Yao D, Willison HJ. Axolemmal nanoruptures arising from paranodal membrane injury induce secondary axon degeneration in murine Guillain-Barré syndrome. J Peripher Nerv Syst 2023; 28:17-31. [PMID: 36710500 PMCID: PMC10947354 DOI: 10.1111/jns.12532] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
The major determinant of poor outcome in Guillain-Barré syndrome (GBS) is axonal degeneration. Pathways leading to primary axonal injury in the motor axonal variant are well established, whereas mechanisms of secondary axonal injury in acute inflammatory demyelinating polyneuropathy (AIDP) are unknown. We recently developed an autoantibody-and complement-mediated model of murine AIDP, in which prominent injury to glial membranes at the node of Ranvier results in severe disruption to paranodal components. Acutely, axonal integrity was maintained, but over time secondary axonal degeneration occurred. Herein, we describe the differential mechanisms underlying acute glial membrane injury and secondary axonal injury in this model. Ex vivo nerve-muscle explants were injured for either acute or extended periods with an autoantibody-and complement-mediated injury to glial paranodal membranes. This model was used to test several possible mechanisms of axon degeneration including calpain activation, and to monitor live axonal calcium signalling. Glial calpains induced acute disruption of paranodal membrane proteins in the absence of discernible axonal injury. Over time, we observed progressive axonal degeneration which was markedly attenuated by axon-specific calpain inhibition. Injury was unaffected by all other tested methods of protection. Trans-axolemmal diffusion of fluorescent proteins and live calcium imaging studies indirectly demonstrated the presence of nanoruptures in the axon membrane. This study outlines one mechanism by which secondary axonal degeneration arises in the AIDP variant of GBS where acute paranodal loop injury is prominent. The data also support the development of calpain inhibitors to attenuate both primary and secondary axonal degeneration in GBS.
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Affiliation(s)
| | - Rhona McGonigal
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
| | | | | | - Denggao Yao
- School of Infection & ImmunityUniversity of GlasgowGlasgowUK
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25
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Yang Z, Yu Z, Xiao B. Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways. Neurosci Bull 2023; 39:453-465. [PMID: 36352321 PMCID: PMC10043148 DOI: 10.1007/s12264-022-00967-x] [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: 03/11/2022] [Accepted: 06/27/2022] [Indexed: 11/11/2022] Open
Abstract
Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.
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Affiliation(s)
- Zhiwen Yang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Zongyan Yu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
| | - Bo Xiao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
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26
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Takenaka T, Ohnishi Y, Yamamoto M, Setoyama D, Kishima H. Glycolytic System in Axons Supplement Decreased ATP Levels after Axotomy of the Peripheral Nerve. eNeuro 2023; 10:ENEURO.0353-22.2023. [PMID: 36894321 PMCID: PMC10035771 DOI: 10.1523/eneuro.0353-22.2023] [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: 08/30/2022] [Revised: 02/04/2023] [Accepted: 02/25/2023] [Indexed: 03/11/2023] Open
Abstract
Wallerian degeneration (WD) occurs in the early stages of numerous neurologic disorders, and clarifying WD pathology is crucial for the advancement of neurologic therapies. ATP is acknowledged as one of the key pathologic substances in WD. The ATP-related pathologic pathways that regulate WD have been defined. The elevation of ATP levels in axon contributes to delay WD and protects axons. However, ATP is necessary for the active processes to proceed WD, given that WD is stringently managed by auto-destruction programs. But little is known about the bioenergetics during WD. In this study, we made sciatic nerve transection models for GO-ATeam2 knock-in rats and mice. We presented the spatiotemporal ATP distribution in the injured axons with in vivo ATP imaging systems, and investigated the metabolic source of ATP in the distal nerve stump. A gradual decrease in ATP levels was observed before the progression of WD. In addition, the glycolytic system and monocarboxylate transporters (MCTs) were activated in Schwann cells following axotomy. Interestingly, in axons, we found the activation of glycolytic system and the inactivation of the tricarboxylic acid (TCA) cycle. Glycolytic inhibitors, 2-deoxyglucose (2-DG) and MCT inhibitors, a-cyano-4-hydroxycinnamic acid (4-CIN) decreased ATP and enhanced WD progression, whereas mitochondrial pyruvate carrier (MPC) inhibitors (MSDC-0160) did not change. Finally, ethyl pyruvate (EP) increased ATP levels and delayed WD. Together, our findings suggest that glycolytic system, both in Schwann cells and axons, is the main source of maintaining ATP levels in the distal nerve stump.
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Affiliation(s)
- Tomofumi Takenaka
- Department of neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, Osaka, 564-8565, Japan
| | - Yuichiro Ohnishi
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, Osaka, 564-8565, Japan
- Department of Neurosurgery, Osaka Gyoumeikan Hospital, Osaka, 554-0012, Japan
| | - Masamichi Yamamoto
- Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, Osaka, 564-8565, Japan
| | - Daiki Setoyama
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Haruhiko Kishima
- Department of neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
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27
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Hornemann T. Serine deficiency causes complications in diabetes. Nature 2023; 614:42-43. [PMID: 36697725 DOI: 10.1038/d41586-023-00054-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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28
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Barnes-Vélez JA, Aksoy Yasar FB, Hu J. Myelin lipid metabolism and its role in myelination and myelin maintenance. Innovation (N Y) 2023; 4:100360. [PMID: 36588745 PMCID: PMC9800635 DOI: 10.1016/j.xinn.2022.100360] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Myelin is a specialized cell membrane indispensable for rapid nerve conduction. The high abundance of membrane lipids is one of myelin's salient features that contribute to its unique role as an insulator that electrically isolates nerve fibers across their myelinated surface. The most abundant lipids in myelin include cholesterol, glycosphingolipids, and plasmalogens, each playing critical roles in myelin development as well as function. This review serves to summarize the role of lipid metabolism in myelination and myelin maintenance, as well as the molecular determinants of myelin lipid homeostasis, with an emphasis on findings from genetic models. In addition, the implications of myelin lipid dysmetabolism in human diseases are highlighted in the context of hereditary leukodystrophies and neuropathies as well as acquired disorders such as Alzheimer's disease.
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Affiliation(s)
- Joseph A. Barnes-Vélez
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR 00936-5067, USA
| | - Fatma Betul Aksoy Yasar
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
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29
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Mitochondrial remodelling is essential for female germ cell differentiation and survival. PLoS Genet 2023; 19:e1010610. [PMID: 36696418 PMCID: PMC9901744 DOI: 10.1371/journal.pgen.1010610] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 02/06/2023] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Stem cells often possess immature mitochondria with few inner membrane invaginations, which increase as stem cells differentiate. Despite this being a conserved feature across many stem cell types in numerous organisms, how and why mitochondria undergo such remodelling during stem cell differentiation has remained unclear. Here, using Drosophila germline stem cells (GSCs), we show that Complex V drives mitochondrial remodelling during the early stages of GSC differentiation, prior to terminal differentiation. This endows germline mitochondria with the capacity to generate large amounts of ATP required for later egg growth and development. Interestingly, impairing mitochondrial remodelling prior to terminal differentiation results in endoplasmic reticulum (ER) lipid bilayer stress, Protein kinase R-like ER kinase (PERK)-mediated activation of the Integrated Stress Response (ISR) and germ cell death. Taken together, our data suggest that mitochondrial remodelling is an essential and tightly integrated aspect of stem cell differentiation. This work sheds light on the potential impact of mitochondrial dysfunction on stem and germ cell function, highlighting ER lipid bilayer stress as a potential major driver of phenotypes caused by mitochondrial dysfunction.
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30
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Quiroz-Aldave J, Durand-Vásquez M, Gamarra-Osorio E, Suarez-Rojas J, Jantine Roseboom P, Alcalá-Mendoza R, Coronado-Arroyo J, Zavaleta-Gutiérrez F, Concepción-Urteaga L, Concepción-Zavaleta M. Diabetic neuropathy: Past, present, and future. CASPIAN JOURNAL OF INTERNAL MEDICINE 2023; 14:153-169. [PMID: 37223297 PMCID: PMC10201131 DOI: 10.22088/cjim.14.2.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/03/2022] [Accepted: 09/06/2022] [Indexed: 05/25/2023]
Abstract
Background A sedentary lifestyle and an unhealthy diet have considerably increased the incidence of diabetes mellitus worldwide in recent decades, which has generated a high rate of associated chronic complications. Methods A narrative review was performed in MEDLINE, EMBASES and SciELO databases, including 162 articles. Results Diabetic neuropathy (DN) is the most common of these complications, mainly producing two types of involvement: sensorimotor neuropathy, whose most common form is symmetric distal polyneuropathy, and autonomic neuropathies, affecting the cardiovascular, gastrointestinal, and urogenital system. Although hyperglycemia is the main metabolic alteration involved in its genesis, the presents of obesity, dyslipidemia, arterial hypertension, and smoking, play an additional role in its appearance. In the pathophysiology, three main phenomena stand out: oxidative stress, the formation of advanced glycosylation end-products, and microvasculature damage. Diagnosis is clinical, and it is recommended to use a 10 g monofilament and a 128 Hz tuning fork as screening tools. Glycemic control and non-pharmacological interventions constitute the mainstay of DN treatment, although there are currently investigations in antioxidant therapies, in addition to pain management. Conclusions Diabetes mellitus causes damage to peripheral nerves, being the most common form of this, distal symmetric polyneuropathy. Control of glycemia and comorbidities contribute to prevent, postpone, and reduce its severity. Pharmacological interventions are intended to relieve pain.
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Affiliation(s)
| | | | | | | | - Pela Jantine Roseboom
- Division of Emergency Medicine, Hospital Regional Docente de Trujillo, Trujillo, Peru
| | - Rosa Alcalá-Mendoza
- Division of Physical Medicine and Rehabilitation, Hospital Víctor Lazarte Echegaray, Trujillo, Peru
| | - Julia Coronado-Arroyo
- Division of Obstetrics and Gynecology, Hospital Nacional Edgardo Rebagliati Martins, Lima, Peru
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31
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Sanaye MM, Kavishwar SA. Diabetic Neuropathy: Review on Molecular Mechanisms. Curr Mol Med 2023; 23:97-110. [PMID: 34397329 DOI: 10.2174/1566524021666210816093111] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 12/16/2022]
Abstract
Diabetic mellitus is a worldwide endocrine and metabolic disorder with insulin insensitivity or deficiency or both whose prevalence could rise up to 592 million by 2035. Consistent hyperglycemia leads to one of the most common comorbidities like Diabetic Peripheral Neuropathy (DPN). DPN is underlined with unpleasant sensory experience, such as tingling and burning sensation, hyperalgesia, numbness, etc. Globally, 50-60% of the diabetic population is suffering from such symptoms as microvascular complications. Consistent hyperglycemia during DM causes activation/inhibition of various pathways playing important role in the homeostasis of neurons and other cells. Disruption of these pathways results into apoptosis and mitochondrial dysfunctions, causing neuropathy. Among these, pathways like Polyol and PARP are some of the most intensively studied ones whereas those like Wnt pathway, Mitogen activated protein kinase (MAPK), mTOR pathway are comparatively newly discovered. Understanding of these pathways and their role in pathophysiology of DN underlines a few molecules of immense therapeutic value. The inhibitors or activators of these molecules can be of therapeutic importance in the management of DPN. This review, hence, focuses on these underlying molecular mechanisms intending to provide therapeutically effective molecular targets for the treatment of DPN.
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Affiliation(s)
- Mrinal M Sanaye
- Department of Pharmacology, Prin. K.M. Kundnani College of Pharmacy, Mumbai-400005, India
| | - Samruddhi A Kavishwar
- Department of Pharmacology, Prin. K.M. Kundnani College of Pharmacy, Mumbai-400005, India
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32
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García-Fernández P, Höfflin K, Rausch A, Strommer K, Neumann A, Cebulla N, Reinhold AK, Rittner H, Üçeyler N, Sommer C. Systemic inflammatory markers in patients with polyneuropathies. Front Immunol 2023; 14:1067714. [PMID: 36860843 PMCID: PMC9969086 DOI: 10.3389/fimmu.2023.1067714] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/31/2023] [Indexed: 02/16/2023] Open
Abstract
Introduction In patients with peripheral neuropathies (PNP), neuropathic pain is present in 50% of the cases, independent of the etiology. The pathophysiology of pain is poorly understood, and inflammatory processes have been found to be involved in neuro-degeneration, -regeneration and pain. While previous studies have found a local upregulation of inflammatory mediators in patients with PNP, there is a high variability described in the cytokines present systemically in sera and cerebrospinal fluid (CSF). We hypothesized that the development of PNP and neuropathic pain is associated with enhanced systemic inflammation. Methods To test our hypothesis, we performed a comprehensive analysis of the protein, lipid and gene expression of different pro- and anti-inflammatory markers in blood and CSF from patients with PNP and controls. Results While we found differences between PNP and controls in specific cytokines or lipids, such as CCL2 or oleoylcarnitine, PNP patients and controls did not present major differences in systemic inflammatory markers in general. IL-10 and CCL2 levels were related to measures of axonal damage and neuropathic pain. Lastly, we describe a strong interaction between inflammation and neurodegeneration at the nerve roots in a specific subgroup of PNP patients with blood-CSF barrier dysfunction. Conclusion In patients with PNP systemic inflammatory, markers in blood or CSF do not differ from controls in general, but specific cytokines or lipids do. Our findings further highlight the importance of CSF analysis in patients with peripheral neuropathies.
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Affiliation(s)
| | - Klemens Höfflin
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
| | - Antonia Rausch
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
| | | | - Astrid Neumann
- Department of Bioanalytics, Bionorica research GmbH, Innsbruck, Austria
| | - Nadine Cebulla
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
| | - Ann-Kristin Reinhold
- Department of Anesthesiology, University Hospital of Würzburg, Würzburg, Germany
| | - Heike Rittner
- Department of Anesthesiology, University Hospital of Würzburg, Würzburg, Germany
| | - Nurcan Üçeyler
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
| | - Claudia Sommer
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
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33
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Schwann cell functions in peripheral nerve development and repair. Neurobiol Dis 2023; 176:105952. [PMID: 36493976 DOI: 10.1016/j.nbd.2022.105952] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The glial cell of the peripheral nervous system (PNS), the Schwann cell (SC), counts among the most multifaceted cells of the body. During development, SCs secure neuronal survival and participate in axonal path finding. Simultaneously, they orchestrate the architectural set up of the developing nerves, including the blood vessels and the endo-, peri- and epineurial layers. Perinatally, in rodents, SCs radially sort and subsequently myelinate individual axons larger than 1 μm in diameter, while small calibre axons become organised in non-myelinating Remak bundles. SCs have a vital role in maintaining axonal health throughout life and several specialized SC types perform essential functions at specific locations, such as terminal SC at the neuromuscular junction (NMJ) or SC within cutaneous sensory end organs. In addition, neural crest derived satellite glia maintain a tight communication with the soma of sensory, sympathetic, and parasympathetic neurons and neural crest derivatives are furthermore an indispensable part of the enteric nervous system. The remarkable plasticity of SCs becomes evident in the context of a nerve injury, where SC transdifferentiate into intriguing repair cells, which orchestrate a regenerative response that promotes nerve repair. Indeed, the multiple adaptations of SCs are captivating, but remain often ill-resolved on the molecular level. Here, we summarize and discuss the knowns and unknowns of the vast array of functions that this single cell type can cover in peripheral nervous system development, maintenance, and repair.
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Girardi KDCDV, Mietto BS, Dos Anjos Lima K, Atella GC, da Silva DS, Pereira AMR, Rosa PS, Lara FA. Phenolic glycolipid-1 of Mycobacterium leprae is involved in human Schwann cell line ST8814 neurotoxic phenotype. J Neurochem 2023; 164:158-171. [PMID: 36349509 DOI: 10.1111/jnc.15722] [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: 02/02/2022] [Revised: 09/06/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022]
Abstract
Leprosy is a chronic infectious disease caused by Mycobacterium leprae infection in Schwann cells. Axonopathy is considered a hallmark of leprosy neuropathy and is associated with the irreversible motor and sensory loss seen in infected patients. Although M. leprae is recognized to provoke Schwann cell dedifferentiation, the mechanisms involved in the contribution of this phenomenon to neural damage remain unclear. In the present work, we used live M. leprae to infect the immortalized human Schwann cell line ST8814. The neurotoxicity of infected Schwann cell-conditioned medium (SCCM) was then evaluated in a human neuroblastoma cell lineage and mouse neurons. ST8814 Schwann cells exposed to M. leprae affected neuronal viability by deviating glial 14 C-labeled lactate, important fuel of neuronal central metabolism, to de novo lipid synthesis. The phenolic glycolipid-1 (PGL-1) is a specific M. leprae cell wall antigen proposed to mediate bacterial-Schwann cell interaction. Therefore, we assessed the role of the PGL-1 on Schwann cell phenotype by using transgenic M. bovis (BCG)-expressing the M. leprae PGL-1. We observed that BCG-PGL-1 was able to induce a phenotype similar to M. leprae, unlike the wild-type BCG strain. We next demonstrated that this Schwann cell neurotoxic phenotype, induced by M. leprae PGL-1, occurs through the protein kinase B (Akt) pathway. Interestingly, the pharmacological inhibition of Akt by triciribine significantly reduced free fatty acid content in the SCCM from M. leprae- and BCG-PGL-1-infected Schwann cells and, hence, preventing neuronal death. Overall, these findings provide novel evidence that both M. leprae and PGL-1, induce a toxic Schwann cell phenotype, by modifying the host lipid metabolism, resulting in profound implications for neuronal loss. We consider this metabolic rewiring a new molecular mechanism to be the basis of leprosy neuropathy.
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Affiliation(s)
| | - Bruno Siqueira Mietto
- Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Karoline Dos Anjos Lima
- Laboratório de Bioquímica de Lipídeos e Lipoproteínas, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Geórgia Correa Atella
- Laboratório de Bioquímica de Lipídeos e Lipoproteínas, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Débora Santos da Silva
- Laboratório de Microbiologia Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | | | - Flavio Alves Lara
- Laboratório de Microbiologia Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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Corty MM, Hulegaard AL, Hill JQ, Sheehan AE, Aicher SA, Freeman MR. Discoidin domain receptor regulates ensheathment, survival and caliber of peripheral axons. Development 2022; 149:281293. [PMID: 36355066 PMCID: PMC10112903 DOI: 10.1242/dev.200636] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 10/27/2022] [Indexed: 11/12/2022]
Abstract
Most invertebrate axons and small-caliber axons in mammalian peripheral nerves are unmyelinated but still ensheathed by glia. Here, we use Drosophila wrapping glia to study the development and function of non-myelinating axon ensheathment, which is poorly understood. Selective ablation of these glia from peripheral nerves severely impaired larval locomotor behavior. In an in vivo RNA interference screen to identify glial genes required for axon ensheathment, we identified the conserved receptor tyrosine kinase Discoidin domain receptor (Ddr). In larval peripheral nerves, loss of Ddr resulted in severely reduced ensheathment of axons and reduced axon caliber, and we found a strong dominant genetic interaction between Ddr and the type XV/XVIII collagen Multiplexin (Mp), suggesting that Ddr functions as a collagen receptor to drive axon wrapping. In adult nerves, loss of Ddr decreased long-term survival of sensory neurons and significantly reduced axon caliber without overtly affecting ensheathment. Our data establish essential roles for non-myelinating glia in nerve development, maintenance and function, and identify Ddr as a key regulator of axon-glia interactions during ensheathment and establishment of axon caliber.
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Affiliation(s)
- Megan M Corty
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | | | - Jo Q Hill
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Amy E Sheehan
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Sue A Aicher
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Marc R Freeman
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
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36
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Wang P, Liu B, Rong T, Wu B. Is diabetes the risk factor for poor neurological recovery after cervical spine surgery? A review of the literature. Eur J Med Res 2022; 27:263. [PMID: 36419189 PMCID: PMC9686083 DOI: 10.1186/s40001-022-00879-6] [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] [Received: 06/10/2022] [Accepted: 11/01/2022] [Indexed: 11/25/2022] Open
Abstract
The poor prognosis of cervical spine surgery is mainly manifested as poor neurological recovery and the presence of new upper extremity dysfunction that promotes significant psychological and physiological burdens on patients. Many factors influence the prognosis of cervical spine surgery, including the age of patients, the time and mode of surgery, and the surgical technique used. However, in clinical studies, it has been observed that patients with diabetes have a higher probability of poor prognosis after surgery. Therefore, we review the pathophysiology of diabetic neuropathies and discuss its impact on cervical nerve system function, especially in cervical nerve roots and upper limb peripheral nerve conduction.
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Intisar A, Shin HY, Kim W, Kang HG, Kim MY, Kim YS, Cho Y, Mo YJ, Lim H, Lee S, Lu QR, Lee Y, Kim MS. Implantable Electroceutical Approach Improves Myelination by Restoring Membrane Integrity in a Mouse Model of Peripheral Demyelinating Neuropathy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201358. [PMID: 35975427 PMCID: PMC9661852 DOI: 10.1002/advs.202201358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Although many efforts are undertaken to treat peripheral demyelinating neuropathies based on biochemical interventions, unfortunately, there is no approved treatment yet. Furthermore, previous studies have not shown improvement of the myelin membrane at the biomolecular level. Here, an electroceutical treatment is introduced as a biophysical intervention to treat Charcot-Marie-Tooth (CMT) disease-the most prevalent peripheral demyelinating neuropathy worldwide-using a mouse model. The specific electrical stimulation (ES) condition (50 mV mm-1 , 20 Hz, 1 h) for optimal myelination is found via an in vitro ES screening system, and its promyelinating effect is validated with ex vivo dorsal root ganglion model. Biomolecular investigation via time-of-flight secondary ion mass spectrometry shows that ES ameliorates distribution abnormalities of peripheral myelin protein 22 and cholesterol in the myelin membrane, revealing the restoration of myelin membrane integrity. ES intervention in vivo via flexible implantable electrodes shows not only gradual rehabilitation of mouse behavioral phenotypes (balance and endurance), but also restored myelin thickness, compactness, and membrane integrity. This study demonstrates, for the first time, that an electroceutical approach with the optimal ES condition has the potential to treat CMT disease and restore impaired myelin membrane integrity, shifting the paradigm toward practical interventions for peripheral demyelinating neuropathies.
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Affiliation(s)
- Aseer Intisar
- Department of New BiologyDGISTDaegu42988Republic of Korea
| | - Hyun Young Shin
- CTCELLS Corp.Daegu42988Republic of Korea
- SBCure Corp.Daegu43017Republic of Korea
| | | | - Hyun Gyu Kang
- Department of New BiologyDGISTDaegu42988Republic of Korea
| | - Min Young Kim
- Department of New BiologyDGISTDaegu42988Republic of Korea
| | - Yu Seon Kim
- Well Aging Research CenterDGISTDaegu42988Republic of Korea
| | - Youngjun Cho
- Department of Robotics and Mechatronics EngineeringDGISTDaegu42988Republic of Korea
| | - Yun Jeoung Mo
- Well Aging Research CenterDGISTDaegu42988Republic of Korea
| | - Heejin Lim
- Department of New BiologyDGISTDaegu42988Republic of Korea
| | - Sanghoon Lee
- Department of Robotics and Mechatronics EngineeringDGISTDaegu42988Republic of Korea
| | - Q. Richard Lu
- Department of PediatricsCincinnati Children's Hospital Medical CenterCincinnatiOH45229USA
| | - Yun‐Il Lee
- Well Aging Research CenterDGISTDaegu42988Republic of Korea
| | - Minseok S. Kim
- Department of New BiologyDGISTDaegu42988Republic of Korea
- CTCELLS Corp.Daegu42988Republic of Korea
- Translational Responsive Medicine Center (TRMC)DGISTDaegu42988Republic of Korea
- New Biology Research Center (NBRC)DGISTDaegu42988Republic of Korea
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38
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Reed CB, Feltri ML, Wilson ER. Peripheral glia diversity. J Anat 2022; 241:1219-1234. [PMID: 34131911 PMCID: PMC8671569 DOI: 10.1111/joa.13484] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Recent years have seen an evolving appreciation for the role of glial cells in the nervous system. As we move away from the typical neurocentric view of neuroscience, the complexity and variability of central nervous system glia is emerging, far beyond the three main subtypes: astrocytes, oligodendrocytes, and microglia. Yet the diversity of the glia found in the peripheral nervous system remains rarely discussed. In this review, we discuss the developmental origin, morphology, and function of the different populations of glia found in the peripheral nervous system, including: myelinating Schwann cells, Remak Schwann cells, repair Schwann cells, satellite glia, boundary cap-derived glia, perineurial glia, terminal Schwann cells, glia found in the skin, olfactory ensheathing cells, and enteric glia. The morphological and functional heterogeneity of glia found in the periphery reflects the diverse roles the nervous system performs throughout the body. Further, it highlights a complexity that should be appreciated and considered when it comes to a complete understanding of the peripheral nervous system in health and disease.
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Affiliation(s)
- Chelsey B Reed
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Emma R Wilson
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
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Liu S, Liu S, Jiang H. Multifaceted roles of mitochondrial stress responses under ETC dysfunction - repair, destruction and pathogenesis. FEBS J 2022; 289:6994-7013. [PMID: 34918460 DOI: 10.1111/febs.16323] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 01/13/2023]
Abstract
Electron transport chain (ETC) dysfunction is a common feature of mitochondrial diseases and induces severe cellular stresses, including mitochondrial membrane potential (Δψm ) reduction, mitochondrial matrix acidification, metabolic derangements and proteostatic stresses. Extensive studies of ETC dysfunction in yeast, Caenorhabditis elegans, cultured cells and mouse models have revealed multiple mitochondrial stress response pathways. Here, we summarise the current understanding of the triggers, sensors, signalling mechanisms and the functional outcomes of mitochondrial stress responses in different species. We highlight Δψm reduction as a major trigger of stress responses in different species, but the responses are species-specific and the outcomes are context-dependent. ETC dysfunction elicits a mitochondrial unfolded protein response (UPRmt ) to repair damaged mitochondria in C. elegans, and activates a global adaptive programme to maintain Δψm in yeast. Yeast and C. elegans responses are remarkably similar at the downstream responses, although they are activated by different signalling mechanisms. UPRmt generally protects ETC-defective worms, but its constitutive activation is toxic for wildtype worms and worms carrying mutant mtDNA. In contrast to lower organisms, ETC dysfunction in mammals mainly activates a mitochondrial integrated stress response (ISRmt ) to reprogramme metabolism and a PINK1-Parkin mitophagy pathway to degrade damaged mitochondria. Accumulating in vivo results suggest that the ATF4 branch of ISRmt exacerbates metabolic derangements to accelerate mitochondrial disease progression. The in vivo roles of mitophagy in mitochondrial diseases are also context-dependent. These results thus reveal the common and unique aspects of mitochondrial stress responses in different species and highlight their multifaceted roles in mitochondrial diseases.
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Affiliation(s)
- Shanshan Liu
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Siqi Liu
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Hui Jiang
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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40
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Deck M, Van Hameren G, Campbell G, Bernard-Marissal N, Devaux J, Berthelot J, Lattard A, Médard JJ, Gautier B, Guelfi S, Abbou S, Quintana P, Chao de la Barca JM, Reynier P, Lenaers G, Chrast R, Tricaud N. Physiology of PNS axons relies on glycolytic metabolism in myelinating Schwann cells. PLoS One 2022; 17:e0272097. [PMID: 36194565 PMCID: PMC9531822 DOI: 10.1371/journal.pone.0272097] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 07/12/2022] [Indexed: 11/18/2022] Open
Abstract
While lactate shuttle theory states that glial cells metabolize glucose into lactate to shuttle it to neurons, how glial cells support axonal metabolism and function remains unclear. Lactate production is a common occurrence following anaerobic glycolysis in muscles. However, several other cell types, including some stem cells, activated macrophages and tumor cells, can produce lactate in presence of oxygen and cellular respiration, using Pyruvate Kinase 2 (PKM2) to divert pyruvate to lactate dehydrogenase. We show here that PKM2 is also upregulated in myelinating Schwann cells (mSC) of mature mouse sciatic nerve versus postnatal immature nerve. Deletion of this isoform in PLP-expressing cells in mice leads to a deficit of lactate in mSC and in peripheral nerves. While the structure of myelin sheath was preserved, mutant mice developed a peripheral neuropathy. Peripheral nerve axons of mutant mice failed to maintain lactate homeostasis upon activity, resulting in an impaired production of mitochondrial ATP. Action potential propagation was not altered but axonal mitochondria transport was slowed down, muscle axon terminals retracted and motor neurons displayed cellular stress. Additional reduction of lactate availability through dichloroacetate treatment, which diverts pyruvate to mitochondrial oxidative phosphorylation, further aggravated motor dysfunction in mutant mice. Thus, lactate production through PKM2 enzyme and aerobic glycolysis is essential in mSC for the long-term maintenance of peripheral nerve axon physiology and function.
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Affiliation(s)
- Marie Deck
- INM, INSERM, Université de Montpellier, Montpellier, France
- * E-mail: (NT); (MD)
| | | | | | | | - Jérôme Devaux
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jade Berthelot
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Alise Lattard
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jean-Jacques Médard
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Benoît Gautier
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Sophie Guelfi
- INM, INSERM, Université de Montpellier, Montpellier, France
| | | | | | - Juan Manuel Chao de la Barca
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Pascal Reynier
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Guy Lenaers
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Roman Chrast
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Nicolas Tricaud
- I-Stem, UEVE/UPS U861, INSERM, AFM, Corbeil-Essonnes, France
- * E-mail: (NT); (MD)
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Zhao S, Che F, Yang L, Zheng Y, Wang D, Yang Y, Wang Y. First report of paternal uniparental disomy of chromosome 8 with SLC52A2 mutation in Brown-vialetto-van laere syndrome type 2 and an analysis of genotype-phenotype correlations. Front Genet 2022; 13:977914. [PMID: 36186484 PMCID: PMC9520306 DOI: 10.3389/fgene.2022.977914] [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] [Received: 06/25/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose: This study reports the clinical and genetic features of Brown-Vialetto-Van Laere syndrome (BVVL) type 2 in a case of uniparental disomy of chromosome 8 in mainland China and analyzes the genotype-phenotype correlation through a review of the literature of BVVL type 2 cases. Methods: The clinical characteristics, treatment, and follow-up data of the patient were summarized, and the etiology was identified by whole-exome sequencing and gene chip analysis. Correlations between the genotype and phenotype were analyzed by collecting clinical and genetic data of published cases and our patient. Results: We identified a homozygous mutation in SLC52A2 (NM_001253815.2 c.1255G>A) by trio-WES. Sanger sequencing confirmed that his father was heterozygous and his mother was wild type. Subsequently, paternal uniparental disomy of chromosome 8 [UPD (8)pat] was confirmed by chromosomal microarray analysis.The patient received long-term oral riboflavin treatment (7 mg/kg.d) and was followed up for 40 months by which time the child’s bulbar palsy, ataxia, and motor function had improved. A review of the literature and statistical analysis found that the symptoms of BVVL type 2 appear at the earliest shortly after birth and at the latest at 10 years of age. The median age of onset was 2.5 years, but the overall delay in diagnosis was a median of 5.6 years. The most common symptoms were hearing loss (83.9%), followed by muscle weakness (80.6%), visual impairment (64.5%), and ataxia (61.3%). To date, a total of 32 mutations in the SLC52A2 gene have been reported, with the most common being a missense mutation. Mutations occur throughout the length of the gene apart from at the N-terminus. In patients with missense mutations, homozygous pattern was more likely to present with ataxia as the first symptom (p < 0.05), while compound heterozygous pattern was more likely to develop respiratory insufficiency during the course of disease (p < 0.001). Moreover, patients with one missense mutation located in inside the transmembrane domain were more likely to have respiratory insufficiency than those with mutations both inside and outside the domain (p < 0.05). Riboflavin supplementation was an important factor in determining prognosis (p < 0.001). Conclusion: We report the first UPD(8)pat with SLC52A2 homozygous pathogenic mutation case in BVVL type 2, which expand the mutation spectrum of gene.
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Affiliation(s)
- Siyu Zhao
- Department of Pediatric neurology, Xi’an Children’s hospital, Xi’an, China
| | - Fengyu Che
- Shaanxi Institute of Pediatric Diseases, Xi’an Children’s Hospital, Xi’an, China
| | - Le Yang
- Department of Pediatric neurology, Xi’an Children’s hospital, Xi’an, China
| | - Yanyan Zheng
- Department of Pediatric neurology, Xi’an Children’s hospital, Xi’an, China
| | - Dong Wang
- Department of Pediatric neurology, Xi’an Children’s hospital, Xi’an, China
| | - Ying Yang
- Shaanxi Institute of Pediatric Diseases, Xi’an Children’s Hospital, Xi’an, China
- *Correspondence: Ying Yang, Yan Wang,
| | - Yan Wang
- Department of Pediatric neurology, Xi’an Children’s hospital, Xi’an, China
- *Correspondence: Ying Yang, Yan Wang,
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42
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Lim JZM, Burgess J, Ooi CG, Ponirakis G, Malik RA, Wilding JPH, Alam U. The Peripheral Neuropathy Prevalence and Characteristics Are Comparable in People with Obesity and Long-Duration Type 1 Diabetes. Adv Ther 2022; 39:4218-4229. [PMID: 35867275 PMCID: PMC9402741 DOI: 10.1007/s12325-022-02208-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 05/26/2022] [Indexed: 12/02/2022]
Abstract
INTRODUCTION Peripheral neuropathy is reported in obesity even in the absence of hyperglycaemia. OBJECTIVE To compare the prevalence and characterise the phenotype of peripheral neuropathy in people living with obesity (OB) and long-duration type 1 diabetes (T1D). PATIENTS AND METHODS We performed a prospective cross-sectional study of 130 participants including healthy volunteers (HV) (n = 28), people with T1D (n = 51), and OB (BMI 30-50 kg/m2) (n = 51). Participants underwent assessment of neuropathic symptoms (Neuropathy Symptom Profile, NSP), neurological deficits (Neuropathy Disability Score, NDS), vibration perception threshold (VPT) and evaluation of sural nerve conduction velocity and amplitude. RESULTS Peripheral neuropathy was present in 43.1% of people with T1D (age 49.9 ± 12.9 years; duration of diabetes 23.4 ± 13.5 years) and 33.3% of OB (age 48.2 ± 10.8 years). VPT for high risk of neuropathic foot ulceration (VPT ≥ 25 V) was present in 31.4% of T1D and 19.6% of OB. Participants living with OB were heavier (BMI 42.9 ± 3.5 kg/m2) and had greater centripetal adiposity with an increased body fat percentage (FM%) (P < 0.001) and waist circumference (WC) (P < 0.001) compared to T1D. The OB group had a higher NDS (P < 0.001), VAS for pain (P < 0.001), NSP (P < 0.001), VPT (P < 0.001) and reduced sural nerve conduction velocity (P < 0.001) and amplitude (P < 0.001) compared to HV, but these parameters were comparable in T1D. VPT was positively associated with increased WC (P = 0.011), FM% (P = 0.001) and HbA1c (P < 0.001) after adjusting for age (R2 = 0.547). Subgroup analysis of respiratory quotient (RQ) measured in the OB group did not correlate with VPT (P = 0.788), nerve conduction velocity (P = 0.743) or amplitude (P = 0.677). CONCLUSION The characteristics of peripheral neuropathy were comparable between normoglycaemic people living with obesity and people with long-duration T1D, suggesting that metabolic factors linked to obesity play a pivotal role in the development of peripheral neuropathy. Further studies are needed to investigate the mechanistic link between visceral adiposity and neuropathy.
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Affiliation(s)
- J Z M Lim
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
- Division of Diabetes and Endocrinology, Aintree University Hospital, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - J Burgess
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - C G Ooi
- Division of Diabetes and Endocrinology, Aintree University Hospital, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - G Ponirakis
- Division of Medicine, Qatar Foundation, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - R A Malik
- Division of Medicine, Qatar Foundation, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - J P H Wilding
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
- Division of Diabetes and Endocrinology, Aintree University Hospital, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - Uazman Alam
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK.
- Division of Diabetes and Endocrinology, Aintree University Hospital, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK.
- Department of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Eid SA, Savelieff MG, Eid AA, Feldman EL. Nox, Nox, Are You There? The Role of NADPH Oxidases in the Peripheral Nervous System. Antioxid Redox Signal 2022; 37:613-630. [PMID: 34861780 PMCID: PMC9634986 DOI: 10.1089/ars.2021.0135] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 02/06/2023]
Abstract
Significance: Reactive oxygen species (ROS) contribute to multiple aspects of peripheral nervous system (PNS) biology ranging from physiological processes (e.g., axonal outgrowth and regeneration) to pathophysiology (e.g., nerve degeneration). Although ROS are derived from multiple sources, NADPH oxidase (Nox) family members are dedicated to ROS generation. Noxs are expressed in the PNS, and their overexpression is associated with detrimental effects on nerve function and contributes, at least in part, to peripheral neuropathies. Recent Advances: Of the seven members, studies mostly focused on Nox1, Nox2, and Nox4, which are expressed in the PNS in a cell-specific manner. We have also recently identified human Nox5 in sural nerve biopsies. When maintained at homeostatic levels, Noxs regulate several aspects of peripheral nerve health, most notably neurite outgrowth and axonal regeneration following nerve lesion. While Nox2 and Nox4 dysregulation is a major source of oxidative stress in PNS disorders, including neuropathic pain and diabetic peripheral neuropathy, recent evidence also implicates Nox1 and Nox5. Critical Issues: Although there is compelling evidence for a direct role of Noxs on nerve function, little is known about their subcellular localization, intercellular regulation, and interaction. These, together with redox signaling, are considered crucial components of nerve redox status. In addition, the lack of isoform-specific inhibitors limits conclusions about the physiological role of Noxs in the PNS and their therapeutic potential in peripheral neuropathies. Future Directions: Future research using isoform-specific genetic and pharmacological approaches are therefore needed to better understand the significance of Nox enzymes in PNS (patho) physiology. Antioxid. Redox Signal. 37, 613-630.
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Affiliation(s)
- Stéphanie A. Eid
- Department of Neurology, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Neurology, NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, Michigan, USA
| | - Masha G. Savelieff
- Department of Neurology, NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, Michigan, USA
| | - Assaad A. Eid
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Eva L. Feldman
- Department of Neurology, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Neurology, NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, Michigan, USA
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44
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Rumora AE, Kim B, Feldman EL. A Role for Fatty Acids in Peripheral Neuropathy Associated with Type 2 Diabetes and Prediabetes. Antioxid Redox Signal 2022; 37:560-577. [PMID: 35152728 PMCID: PMC9499450 DOI: 10.1089/ars.2021.0155] [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: 07/15/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 11/12/2022]
Abstract
Significance: As the global prevalence of diabetes rises, diabetic complications are also increasing at an alarming rate. Peripheral neuropathy (PN) is the most prevalent complication of diabetes and prediabetes, and is characterized by progressive sensory loss resulting from nerve damage. While hyperglycemia is the major risk factor for PN in type 1 diabetes (T1D), the metabolic syndrome (MetS) underlies the onset and progression of PN in type 2 diabetes (T2D) and prediabetes. Recent Advances: Recent reports show that dyslipidemia, a MetS component, is strongly associated with PN in T2D and prediabetes. Dyslipidemia is characterized by an abnormal plasma lipid profile with uncontrolled lipid levels, and both clinical and preclinical studies implicate a role for dietary fatty acids (FAs) in PN pathogenesis. Molecular studies further show that saturated and unsaturated FAs differentially regulate the nerve lipid profile and nerve function. Critical Issues: We first review the properties of FAs and the neuroanatomy of the peripheral nervous system (PNS). Second, we discuss clinical and preclinical studies that implicate the involvement of FAs in PN. Third, we summarize the potential effects of FAs on nerve function and lipid metabolism within the peripheral nerves, sensory neurons, and Schwann cells. Future Directions: Future directions will focus on identifying molecular pathways in T2D and prediabetes that are modulated by FAs in PN. Determining pathophysiological mechanisms that underlie the injurious effects of saturated FAs and beneficial properties of unsaturated FAs will provide mechanistic targets for developing new targeted therapies to treat PN associated with T2D and prediabetes. Antioxid. Redox Signal. 37, 560-577.
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Affiliation(s)
- Amy E. Rumora
- Department of Neurology, Columbia University, New York, New York, USA
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
| | - Bhumsoo Kim
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
| | - Eva L. Feldman
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
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Elbaz B, Yang L, Vardy M, Isaac S, Rader BL, Kawaguchi R, Traka M, Woolf CJ, Renthal W, Popko B. Sensory neurons display cell-type-specific vulnerability to loss of neuron-glia interactions. Cell Rep 2022; 40:111130. [PMID: 35858549 PMCID: PMC9354470 DOI: 10.1016/j.celrep.2022.111130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/22/2021] [Accepted: 07/01/2022] [Indexed: 11/11/2022] Open
Abstract
Peripheral nervous system (PNS) injuries initiate transcriptional changes in glial cells and sensory neurons that promote axonal regeneration. While the factors that initiate the transcriptional changes in glial cells are well characterized, the full range of stimuli that initiate the response of sensory neurons remain elusive. Here, using a genetic model of glial cell ablation, we find that glial cell loss results in transient PNS demyelination without overt axonal loss. By profiling sensory ganglia at single-cell resolution, we show that glial cell loss induces a transcriptional injury response preferentially in proprioceptive and Aβ RA-LTMR neurons. The transcriptional response of sensory neurons to mechanical injury has been assumed to be a cell-autonomous response. By identifying a similar response in non-injured, demyelinated neurons, our study suggests that this represents a non-cell-autonomous transcriptional response of sensory neurons to glial cell loss and demyelination.
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Affiliation(s)
- Benayahu Elbaz
- Department of Neurology, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
| | - Lite Yang
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA
| | - Maia Vardy
- Department of Neurology, Northwestern Feinberg School of Medicine, Chicago, IL, USA
| | - Sara Isaac
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Braesen L Rader
- Department of Neurology, Northwestern Feinberg School of Medicine, Chicago, IL, USA
| | - Riki Kawaguchi
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Maria Traka
- Department of Anatomy, College of Graduate Studies, Midwestern University, Downers Grove, IL, USA
| | - Clifford J Woolf
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Circle, Boston, MA 02115, USA
| | - William Renthal
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA
| | - Brian Popko
- Department of Neurology, Northwestern Feinberg School of Medicine, Chicago, IL, USA.
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Smith S, Normahani P, Lane T, Hohenschurz-Schmidt D, Oliver N, Davies AH. Pathogenesis of Distal Symmetrical Polyneuropathy in Diabetes. LIFE (BASEL, SWITZERLAND) 2022; 12:life12071074. [PMID: 35888162 PMCID: PMC9319251 DOI: 10.3390/life12071074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/13/2022]
Abstract
Distal symmetrical polyneuropathy (DSPN) is a serious complication of diabetes associated with significant disability and mortality. Although more than 50% of people with diabetes develop DSPN, its pathogenesis is still relatively unknown. This lack of understanding has limited the development of novel disease-modifying therapies and left the reasons for failed therapies uncertain, which is critical given that current management strategies often fail to achieve long-term efficacy. In this article, the pathogenesis of DSPN is reviewed, covering pathogenic changes in the peripheral nervous system, microvasculature and central nervous system (CNS). Furthermore, the successes and limitations of current therapies are discussed, and potential therapeutic targets are proposed. Recent findings on its pathogenesis have called the definition of DSPN into question and transformed the disease model, paving the way for new research prospects.
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Affiliation(s)
- Sasha Smith
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Pasha Normahani
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Tristan Lane
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Department of Vascular Surgery, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - David Hohenschurz-Schmidt
- Pain Research Group, Department of Surgery and Cancer, Imperial College London, London SW10 9NH, UK;
| | - Nick Oliver
- Section of Metabolic Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London W2 1PG, UK;
- Division of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London W2 1NY, UK
| | - Alun Huw Davies
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
- Correspondence:
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Tricaud N, Gautier B, Berthelot J, Gonzalez S, Van Hameren G. Traumatic and Diabetic Schwann Cell Demyelination Is Triggered by a Transient Mitochondrial Calcium Release through Voltage Dependent Anion Channel 1. Biomedicines 2022; 10:biomedicines10061447. [PMID: 35740468 PMCID: PMC9220872 DOI: 10.3390/biomedicines10061447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
A large number of peripheral neuropathies, among which are traumatic and diabetic peripheral neuropathies, result from the degeneration of the myelin sheath, a process called demyelination. Demyelination does not result from Schwann cell death but from Schwann cell dedifferentiation, which includes reprograming and several catabolic and anabolic events. Starting around 4 h after nerve injury, activation of MAPK/cJun pathways is the earliest characterized step of this dedifferentiation program. Here we show, using real-time in vivo imaging, that Schwann cell mitochondrial pH, motility and calcium content are altered as soon as one hour after nerve injury. Mitochondrial calcium release occurred through the VDAC outer membrane channel and mPTP inner membrane channel. This calcium influx in the cytoplasm induced Schwann-cell demyelination via MAPK/c-Jun activation. Blocking calcium release through VDAC silencing or VDAC inhibitor TRO19622 prevented demyelination. We found that the kinetics of mitochondrial calcium release upon nerve injury were altered in the Schwann cells of diabetic mice suggesting a permanent leak of mitochondrial calcium in the cytoplasm. TRO19622 treatment alleviated peripheral nerve defects and motor deficit in diabetic mice. Together, these data indicate that mitochondrial calcium homeostasis is instrumental in the Schwann cell demyelination program and that blocking VDAC constitutes a molecular basis for developing anti-demyelinating drugs for diabetic peripheral neuropathy.
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Affiliation(s)
- Nicolas Tricaud
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
- I-Stem, UEVE/UPS U861, INSERM U861, AFM, 91100 Corbeil-Essonnes, France
- Correspondence:
| | - Benoit Gautier
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Jade Berthelot
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Sergio Gonzalez
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Gerben Van Hameren
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
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48
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Beirowski B. Emerging evidence for compromised axonal bioenergetics and axoglial metabolic coupling as drivers of neurodegeneration. Neurobiol Dis 2022; 170:105751. [PMID: 35569720 DOI: 10.1016/j.nbd.2022.105751] [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: 03/01/2022] [Revised: 04/20/2022] [Accepted: 05/09/2022] [Indexed: 10/18/2022] Open
Abstract
Impaired bioenergetic capacity of the nervous system is thought to contribute to the pathogenesis of many neurodegenerative diseases (NDD). Since neuronal synapses are believed to be the major energy consumers in the nervous system, synaptic derangements resulting from energy deficits have been suggested to play a central role for the development of many of these disorders. However, long axons constitute the largest compartment of the neuronal network, require large amounts of energy, are metabolically and structurally highly vulnerable, and undergo early injurious stresses in many NDD. These stresses likely impose additional energy demands for continuous adaptations and repair processes, and may eventually overwhelm axonal maintenance mechanisms. Indeed, pathological axon degeneration (pAxD) is now recognized as an etiological focus in a wide array of NDD associated with bioenergetic abnormalities. In this paper I first discuss the recognition that a simple experimental model for pAxD is regulated by an auto-destruction program that exhausts distressed axons energetically. Provision of the energy substrate pyruvate robustly counteracts this axonal breakdown. Importantly, energy decline in axons is not only a consequence but also an initiator of this program. This opens the intriguing possibility that axon dysfunction and pAxD can be suppressed by preemptively energizing distressed axons. Second, I focus on the emerging concept that axons communicate energetically with their flanking glia. This axoglial metabolic coupling can help offset the axonal energy decline that activates the pAxD program but also jeopardize axon integrity as a result of perturbed glial metabolism. Third, I present compelling evidence that abnormal axonal energetics and compromised axoglial metabolic coupling accompany the activation of the pAxD auto-destruction pathway in models of glaucoma, a widespread neurodegenerative condition with pathogenic overlap to other common NDD. In conclusion, I propose a novel conceptual framework suggesting that therapeutic interventions focused on bioenergetic support of the nervous system should also address axons and their metabolic interactions with glia.
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Affiliation(s)
- Bogdan Beirowski
- Institute for Myelin and Glia Exploration, New York State Center of Excellence in Bioinformatics & Life Sciences (CBLS), University at Buffalo, Buffalo, NY 14203, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
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Chandrasekaran K, Najimi N, Sagi AR, Yarlagadda S, Salimian M, Arvas MI, Hedayat AF, Kevas Y, Kadakia A, Russell JW. NAD + Precursors Repair Mitochondrial Function in Diabetes and Prevent Experimental Diabetic Neuropathy. Int J Mol Sci 2022; 23:4887. [PMID: 35563288 PMCID: PMC9102948 DOI: 10.3390/ijms23094887] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/18/2022] [Accepted: 04/26/2022] [Indexed: 12/04/2022] Open
Abstract
Axon degeneration in diabetic peripheral neuropathy (DPN) is associated with impaired NAD+ metabolism. We tested whether the administration of NAD+ precursors, nicotinamide mononucleotide (NMN) or nicotinamide riboside (NR), prevents DPN in models of Type 1 and Type 2 diabetes. NMN was administered to streptozotocin (STZ)-induced diabetic rats and STZ-induced diabetic mice by intraperitoneal injection at 50 or 100 mg/kg on alternate days for 2 months. mice The were fed with a high fat diet (HFD) for 2 months with or without added NR at 150 or 300 mg/kg for 2 months. The administration of NMN to STZ-induced diabetic rats or mice or dietary addition of NR to HFD-fed mice improved sensory function, normalized sciatic and tail nerve conduction velocities, and prevented loss of intraepidermal nerve fibers in skin samples from the hind-paw. In adult dorsal root ganglion (DRG) neurons isolated from HFD-fed mice, there was a decrease in NAD+ levels and mitochondrial maximum reserve capacity. These impairments were normalized in isolated DRG neurons from NR-treated mice. The results indicate that the correction of NAD+ depletion in DRG may be sufficient to prevent DPN but does not significantly affect glucose tolerance, insulin levels, or insulin resistance.
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Affiliation(s)
- Krish Chandrasekaran
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
- Veterans Affairs Medical Center, Baltimore, MD 21201, USA
| | - Neda Najimi
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Avinash R. Sagi
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Sushuma Yarlagadda
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Mohammad Salimian
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Muhammed Ikbal Arvas
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Ahmad F. Hedayat
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Yanni Kevas
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Anand Kadakia
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - James W. Russell
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (A.R.S.); (S.Y.); (M.S.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
- Veterans Affairs Medical Center, Baltimore, MD 21201, USA
- CAMC Institute for Academic Medicine, 415 Morris Street Suite 300, Charleston, WV 25301, USA
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Abstract
Diabetic neuropathy is a commonly occurring complication of diabetes that affects hundreds of millions of patients worldwide. Patients suffering from diabetic neuropathy experience abnormal sensations and have damage in their peripheral nerve axons as well as myelin, a tightly packed Schwann cell sheath that wraps around axons to provide insulation and increases electrical conductivity along the nerve fibers. The molecular events underlying myelin damage in diabetic neuropathy are largely unknown, and there is no efficacious treatment for the disease. The current study, using a diabetic mouse model and human patient nerve samples, uncovered a molecular mechanism underlying myelin sheath damage in diabetic neuropathy and provides a potential treatment strategy for the disease. Demyelination is a pathological feature of diabetic neuropathy, a common and painful complication of diabetes, yet the mechanisms underlying diabetes-induced demyelination remain unclear. Here, we show that targeting mixed lineage kinase domain–like protein (MLKL), a protein critical in necroptosis, using Schwann cell–specific genetic knockout, S441A single–amino acid knockin mutation, or pharmacological inhibition all blocked myelin sheath decompaction and prevented the decrease of nerve conduction velocity in streptozotocin-induced diabetic mice. The decompaction of the myelin sheaths of sural nerves was observed in biopsy samples from diabetic patients, and the MLKL-mediated myelin breakdown was activated in human diabetic neuropathy patients. Our study establishes a direct myelin degradation–related role for MLKL in diabetic neuropathy and defines MLKL as a druggable target for developing agents to prevent or treat diabetic neuropathy.
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