1
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Libberecht K, Vangansewinkel T, Van Den Bosch L, Lambrichts I, Wolfs E. Proteostasis plays an important role in demyelinating Charcot Marie Tooth disease. Biochem Pharmacol 2023; 216:115760. [PMID: 37604292 DOI: 10.1016/j.bcp.2023.115760] [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: 06/01/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/23/2023]
Abstract
Type 1 Charcot-Marie-Tooth disease (CMT1) is the most common demyelinating peripheral neuropathy. Patients suffer from progressive muscle weakness and sensory problems. The underlying disease mechanisms of CMT1 are still unclear and no therapy is currently available, hence patients completely rely on supportive care. Balancing protein levels is a complex multistep process fundamental to maintain cells in their healthy state and a disrupted proteostasis is a hallmark of several neurodegenerative diseases. When protein misfolding occurs, protein quality control systems are activated such as chaperones, the lysosomal-autophagy system and proteasomal degradation to ensure proper degradation. However, in pathological circumstances, these mechanisms are overloaded and thereby become inefficient to clear the load of misfolded proteins. Recent evidence strongly indicates that a disbalance in proteostasis plays an important role in several forms of CMT1. In this review, we present an overview of the protein quality control systems, their role in CMT1, and potential treatment strategies to restore proteostasis.
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Affiliation(s)
- Karen Libberecht
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
| | - Tim Vangansewinkel
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium; UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Ludo Van Den Bosch
- KU Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ivo Lambrichts
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Esther Wolfs
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium.
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2
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Intisar A, Woo H, Kang HG, Kim WH, Shin HY, Kim MY, Kim YS, Mo YJ, Lee YI, Kim MS. Electroceutical approach ameliorates intracellular PMP22 aggregation and promotes pro-myelinating pathways in a CMT1A in vitro model. Biosens Bioelectron 2023; 224:115055. [PMID: 36630746 DOI: 10.1016/j.bios.2022.115055] [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: 10/07/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023]
Abstract
Charcot-Marie-Tooth disease subtype 1A (CMT1A) is one of the most prevalent demyelinating peripheral neuropathies worldwide, caused by duplication of the peripheral myelin protein 22 (PMP22) gene, which is expressed primarily in Schwann cells (SCs). PMP22 overexpression in SCs leads to intracellular aggregation of the protein, which eventually results in demyelination. Unfortunately, previous biochemical approaches have not resulted in an approved treatment for CMT1A disease, compelling the pursuit for a biophysical approach such as electrical stimulation (ES). However, the effects of ES on CMT1A SCs have remained unexplored. In this study, we established PMP22-overexpressed Schwannoma cells as a CMT1A in vitro model, and investigated the biomolecular changes upon applying ES via a custom-made high-throughput ES platform, screening for the condition that delivers optimal therapeutic effects. While PMP22-overexpressed Schwannoma exhibited intracellular PMP22 aggregation, ES at 20 Hz for 1 h improved this phenomenon, bringing PMP22 distribution closer to healthy condition. ES at this condition also enhanced the expression of the genes encoding myelin basic protein (MBP) and myelin-associated glycoprotein (MAG), which are essential for assembling myelin sheath. Furthermore, ES altered the gene expression for myelination-regulating transcription factors Krox-20, Oct-6, c-Jun and Sox10, inducing pro-myelinating effects in PMP22-overexpressed Schwannoma. While electroceuticals has previously been applied in the peripheral nervous system towards acquired peripheral neuropathies such as pain and nerve injury, this study demonstrates its effectiveness towards ameliorating biomolecular abnormalities in an in vitro model of CMT1A, an inherited peripheral neuropathy. These findings will facilitate the clinical translation of an electroceutical treatment for CMT1A.
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Affiliation(s)
- Aseer Intisar
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Hanwoong Woo
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Hyun Gyu Kang
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Woon-Hae Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea
| | - Hyun Young Shin
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea; SBCure Corp., Daegu, 43017, Republic of Korea
| | - Min Young Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Yu Seon Kim
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Yun Jeoung Mo
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Yun-Il Lee
- Well Aging Research Center, DGIST, Daegu, 42988, Republic of Korea
| | - Minseok S Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea; CTCELLS Corp., Daegu, 42988, Republic of Korea; Translational Responsive Medicine Center (TRMC), DGIST, Daegu, 42988, Republic of Korea; New Biology Research Center (NBRC), DGIST, Daegu, 42988, Republic of Korea.
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3
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Kaur S, Zhang X, Patel S, Rodriguez YA, Luther KJ, Alghafli G, Lang RM, Abrams CK, Dobrowsky RT. Pharmacologic Targeting of the C-Terminus of Heat Shock Protein 90 Improves Neuromuscular Function in Animal Models of Charcot Marie Tooth X1 Disease. ACS Pharmacol Transl Sci 2023; 6:306-319. [PMID: 36798471 PMCID: PMC9926526 DOI: 10.1021/acsptsci.2c00223] [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: 11/14/2022] [Indexed: 01/22/2023]
Abstract
Charcot-Marie-Tooth X1 (CMTX1) disease is an inherited peripheral neuropathy that arises from loss-of-function mutations in the protein connexin 32 (Cx32). CMTX1 currently lacks a pharmacologic approach toward disease management, and we have previously shown that modulating the expression of molecular chaperones using novologue therapy may provide a viable disease-modifying approach to treat metabolic and demyelinating neuropathies. Cemdomespib is an orally bioavailable novologue that manifests neuroprotective activity by modulating the expression of heat shock protein 70 (Hsp70). We examined if 1 to 5 months of daily cemdomespib therapy may improve neuropathic symptoms in three mouse models of CMTX1 (Cx32 deficient (Cx32def), T55I-Cx32def, and R75W-Cx32 mice). Daily drug therapy significantly improved motor nerve conduction velocity (MNCV) and grip strength in all three models, but the compound muscle action potential was only improved in Cx32def mice. Drug efficacy required Hsp70 as improvements in MNCV, and the grip strength was abrogated in Cx32def × Hsp70 knockout mice. Five months of novologue therapy was associated with improved neuromuscular junction morphology, femoral motor nerve myelination, reduction in foamy macrophages, and a decrease in Schwann cell c-jun levels. To determine if c-jun may be downstream of Hsp70 and necessary for drug efficacy, c-jun expression was specifically deleted in Schwann cells of Cx32def mice. While the deletion of c-jun worsened the neuropathy, cemdomespib therapy remained effective in improving MNCV and grip strength. Our data show that cemdomespib therapy improves CMTX1-linked neuropathy in an Hsp70-dependent but a c-jun-independent manner and without regard to the nature of the underlying Cx32 mutation.
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Affiliation(s)
- Sukhmanjit Kaur
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Xinyue Zhang
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Sugandha Patel
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Yssa A. Rodriguez
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Kylie J. Luther
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Ghufran Alghafli
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Ryan M. Lang
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
| | - Charles K. Abrams
- Department
of Neurology and Rehabilitation and Biomedical Engineering, College
of Medicine, University of Illinois Chicago, Chicago, Illinois 60612, United States
| | - Rick T. Dobrowsky
- Department
of Pharmacology and Toxicology, University
of Kansas, Lawrence, Kansas 66045, United States
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4
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Transcriptomic Analysis of the Porcine Gut in Response to Heat Stress and Dietary Soluble Fiber from Beet Pulp. Genes (Basel) 2022; 13:genes13081456. [PMID: 36011367 PMCID: PMC9408315 DOI: 10.3390/genes13081456] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/03/2022] [Accepted: 08/14/2022] [Indexed: 11/17/2022] Open
Abstract
This study aimed to investigate the impact of heat stress (HS) and the effects of dietary soluble fiber from beet pulp (BP) on gene expression (differentially expressed genes, DEGs) of the porcine jejunum. Out of the 82 DEGs, 47 genes were up-regulated, and 35 genes were downregulated between treatments. The gene ontology (GO) enrichment analysis showed that the DEGs were related mainly to the actin cytoskeleton organization and muscle structure development in biological processes, cytoplasm, stress fibers, Z disc, cytoskeleton, and the extracellular regions in cellular composition, and actin binding, calcium ion binding, actin filament binding, and pyridoxal phosphate binding in the molecular function. The KEGG pathway analysis showed that the DEGs were involved in hypertrophic cardiomyopathy, dilated cardiomyopathy, vascular smooth muscle contraction, regulation of actin cytoskeleton, mucin type O-glycan biosynthesis, and African trypanosomiasis. Several of the genes (HSPB6, HSP70, TPM1, TAGLN, CCL4) in the HS group were involved in cellular oxidative stress, immune responses, and cellular differentiation. In contrast, the DEGs in the dietary BP group were related to intestinal epithelium integrity and immune response to pathogens, including S100A2, GCNT3, LYZ, SCGB1A1, SAA3, and ST3GAL1. These findings might help understand the HS response and the effect of dietary fiber (DF) regarding HS and be a valuable reference for future studies.
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5
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Curcumin and Ethanol Effects in Trembler-J Schwann Cell Culture. Biomolecules 2022; 12:biom12040515. [PMID: 35454103 PMCID: PMC9025918 DOI: 10.3390/biom12040515] [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: 02/26/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 02/04/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) syndrome is the most common progressive human motor and sensory peripheral neuropathy. CMT type 1E is a demyelinating neuropathy affecting Schwann cells due to peripheral-myelin-protein-22 (PMP22) mutations, modelized by Trembler-J mice. Curcumin, a natural polyphenol compound obtained from turmeric (Curcuma longa), exhibits dose- and time-varying antitumor, antioxidant and neuroprotective properties, however, the neurotherapeutic actions of curcumin remain elusive. Here, we propose curcumin as a possible natural treatment capable of enhancing cellular detoxification mechanisms, resulting in an improvement of the neurodegenerative Trembler-J phenotype. Using a refined method for obtaining enriched Schwann cell cultures, we evaluated the neurotherapeutic action of low dose curcumin treatment on the PMP22 expression, and on the chaperones and autophagy/mammalian target of rapamycin (mTOR) pathways in Trembler-J and wild-type genotypes. In wild-type Schwann cells, the action of curcumin resulted in strong stimulation of the chaperone and macroautophagy pathway, whereas the modulation of ribophagy showed a mild effect. However, despite the promising neuroprotective effects for the treatment of neurological diseases, we demonstrate that the action of curcumin in Trembler-J Schwann cells could be impaired due to the irreversible impact of ethanol used as a common curcumin vehicle necessary for administration. These results contribute to expanding our still limited understanding of PMP22 biology in neurobiology and expose the intrinsic lability of the neurodegenerative Trembler-J genotype. Furthermore, they unravel interesting physiological mechanisms of cellular resilience relevant to the pharmacological treatment of the neurodegenerative Tremble J phenotype with curcumin and ethanol. We conclude that the analysis of the effects of the vehicle itself is an essential and inescapable step to comprehensibly assess the effects and full potential of curcumin treatment for therapeutic purposes.
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6
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Stavrou M, Sargiannidou I, Georgiou E, Kagiava A, Kleopa KA. Emerging Therapies for Charcot-Marie-Tooth Inherited Neuropathies. Int J Mol Sci 2021; 22:6048. [PMID: 34205075 PMCID: PMC8199910 DOI: 10.3390/ijms22116048] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited neuropathies known as Charcot-Marie-Tooth (CMT) disease are genetically heterogeneous disorders affecting the peripheral nerves, causing significant and slowly progressive disability over the lifespan. The discovery of their diverse molecular genetic mechanisms over the past three decades has provided the basis for developing a wide range of therapeutics, leading to an exciting era of finding treatments for this, until now, incurable group of diseases. Many treatment approaches, including gene silencing and gene replacement therapies, as well as small molecule treatments are currently in preclinical testing while several have also reached clinical trial stage. Some of the treatment approaches are disease-specific targeted to the unique disease mechanism of each CMT form, while other therapeutics target common pathways shared by several or all CMT types. As promising treatments reach the stage of clinical translation, optimal outcome measures, novel biomarkers and appropriate trial designs are crucial in order to facilitate successful testing and validation of novel treatments for CMT patients.
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Affiliation(s)
- Marina Stavrou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Irene Sargiannidou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Elena Georgiou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Alexia Kagiava
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Kleopas A. Kleopa
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
- Center for Neuromuscular Diseases, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
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7
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Boutary S, Echaniz-Laguna A, Adams D, Loisel-Duwattez J, Schumacher M, Massaad C, Massaad-Massade L. Treating PMP22 gene duplication-related Charcot-Marie-Tooth disease: the past, the present and the future. Transl Res 2021; 227:100-111. [PMID: 32693030 DOI: 10.1016/j.trsl.2020.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most frequent inherited neuropathy, affecting 1/1500 to 1/10000. CMT1A represents 60%-70% of all CMT and is caused by a duplication on chromosome 17p11.2 leading to an overexpression of the Peripheral Myelin Protein 22 (PMP22). PMP22 gene is under tight regulation and small changes in its expression influences myelination and affect motor and sensory functions. To date, CMT1A treatment is symptomatic and classic pharmacological options have been disappointing. Here, we review the past, present, and future treatment options for CMT1A, with a special emphasis on the highly promising potential of PMP22-targeted small interfering RNA and antisense oligonucleotides.
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Affiliation(s)
- Suzan Boutary
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France
| | - Andoni Echaniz-Laguna
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - David Adams
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - Julien Loisel-Duwattez
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | | | - Charbel Massaad
- Faculty of Basic and Biomedical Sciences, Paris Descartes University, INSERM UMRS 1124, Paris, France
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8
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Chaudhury S, Keegan BM, Blagg BSJ. The role and therapeutic potential of Hsp90, Hsp70, and smaller heat shock proteins in peripheral and central neuropathies. Med Res Rev 2021; 41:202-222. [PMID: 32844464 PMCID: PMC8485878 DOI: 10.1002/med.21729] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/16/2022]
Abstract
Heat shock proteins (Hsps) are molecular chaperones that also play important roles in the activation of the heat shock response (HSR). The HSR is an evolutionary conserved and protective mechanism that is used to counter abnormal physiological conditions, stressors, and disease states, such as those exemplified in cancer and/or neurodegeneration. In normal cells, heat shock factor-1 (HSF-1), the transcription factor that regulates the HSR, remains in a dormant multiprotein complex that is formed upon association with chaperones (Hsp90, Hsp70, etc.), co-chaperones, and client proteins. However, under cellular stress, HSF-1 dissociates from Hsp90 and induces the transcriptional upregulation of Hsp70 to afford protection against the encountered cellular stress. As a consequence of both peripheral and central neuropathies, cellular stress occurs and results in the accumulation of unfolded and/or misfolded proteins, which can be counterbalanced by activation of the HSR. Since Hsp90 is the primary regulator of the HSR, modulation of Hsp90 by small molecules represents an attractive therapeutic approach against both peripheral and central neuropathies.
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Affiliation(s)
- Subhabrata Chaudhury
- Department of Chemistry and Biochemistry, Warren Family Research Center for Drug Discovery and Development, University of Notre Dame, Notre Dame, Indiana, USA
| | - Bradley M Keegan
- Department of Chemistry and Biochemistry, Warren Family Research Center for Drug Discovery and Development, University of Notre Dame, Notre Dame, Indiana, USA
| | - Brian S J Blagg
- Department of Chemistry and Biochemistry, Warren Family Research Center for Drug Discovery and Development, University of Notre Dame, Notre Dame, Indiana, USA
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9
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Electron Microscopy Analysis of Sciatic Nerve Fibers in C57BL/6 Transgenic Mice. NEUROPHYSIOLOGY+ 2020. [DOI: 10.1007/s11062-020-09857-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Marinko JT, Carter BD, Sanders CR. Direct relationship between increased expression and mistrafficking of the Charcot-Marie-Tooth-associated protein PMP22. J Biol Chem 2020; 295:11963-11970. [PMID: 32647009 PMCID: PMC7443497 DOI: 10.1074/jbc.ac120.014940] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 06/30/2020] [Indexed: 12/16/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a neuropathy of the peripheral nervous system that afflicts ∼1:2500 people. The most common form of this disease (CMT1A, 1:4000) is associated with duplication of chromosome fragment 17p11.2-12, which results in a third WT PMP22 allele. In rodent models overexpressing the PMP22 (peripheral myelin protein 22) protein and in dermal fibroblasts from patients with CMT1A, PMP22 aggregates have been observed. This suggests that overexpression of PMP22 under CMT1A conditions overwhelms the endoplasmic reticulum quality control system, leading to formation of cytotoxic aggregates. In this work, we used a single-cell flow-cytometry trafficking assay to quantitatively examine the relationship between PMP22 expression and trafficking efficiency in individual cells. We observed that as expression of WT or disease variants of PMP22 is increased, the amount of intracellular PMP22 increases to a greater extent than the amount of surface-trafficked protein. This was true for both transiently transfected cells and PMP22 stable expressing cells. Our results support the notion that overexpression of PMP22 in CMT1A leads to a disproportionate increase in misfolding and mistrafficking of PMP22, which is likely a contributor to disease pathology and progression.
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Affiliation(s)
- Justin T Marinko
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Bruce D Carter
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt Brain Institute, Nashville, Tennessee, USA
| | - Charles R Sanders
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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11
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Chittoor-Vinod VG, Bazick H, Todd AG, Falk D, Morelli KH, Burgess RW, Foster TC, Notterpek L. HSP90 Inhibitor, NVP-AUY922, Improves Myelination in Vitro and Supports the Maintenance of Myelinated Axons in Neuropathic Mice. ACS Chem Neurosci 2019; 10:2890-2902. [PMID: 31017387 PMCID: PMC6588339 DOI: 10.1021/acschemneuro.9b00105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
![]()
Hereditary
demyelinating neuropathies linked to peripheral myelin
protein 22 (PMP22) involve the disruption of normal protein trafficking
and are therefore relevant targets for chaperone therapy. Using a
small molecule HSP90 inhibitor, EC137, in cell culture models, we
previously validated the chaperone pathway as a viable target for
therapy development. Here, we tested five commercially available inhibitors
of HSP90 and identified BIIB021 and AUY922 to support Schwann cell
viability and enhance chaperone expression. AUY922 showed higher efficacy,
compared to BIIB021, in enhancing myelin synthesis in dorsal root
ganglion explant cultures from neuropathic mice. For in vivo testing,
we randomly assigned 2–3 month old C22 and 6 week old Trembler
J (TrJ) mice to receive two weekly injections of either vehicle or
AUY922 (2 mg/kg). By the intraperitoneal (i.p.) route, the drug was
well-tolerated by all mice over the 5 month long study, without influence
on body weight or general grooming behavior. AUY922 improved the maintenance
of myelinated nerves of both neuropathic models and attenuated the
decline in rotarod performance and peak muscle force production in
C22 mice. These studies highlight the significance of proteostasis
in neuromuscular function and further validate the HSP90 pathway as
a therapeutic target for hereditary neuropathies.
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Affiliation(s)
- Vinita G. Chittoor-Vinod
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Hannah Bazick
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Adrian G. Todd
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Darin Falk
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Kathryn H. Morelli
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Robert W. Burgess
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Thomas C. Foster
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Lucia Notterpek
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
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12
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Marinko J, Huang H, Penn WD, Capra JA, Schlebach JP, Sanders CR. Folding and Misfolding of Human Membrane Proteins in Health and Disease: From Single Molecules to Cellular Proteostasis. Chem Rev 2019; 119:5537-5606. [PMID: 30608666 PMCID: PMC6506414 DOI: 10.1021/acs.chemrev.8b00532] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Advances over the past 25 years have revealed much about how the structural properties of membranes and associated proteins are linked to the thermodynamics and kinetics of membrane protein (MP) folding. At the same time biochemical progress has outlined how cellular proteostasis networks mediate MP folding and manage misfolding in the cell. When combined with results from genomic sequencing, these studies have established paradigms for how MP folding and misfolding are linked to the molecular etiologies of a variety of diseases. This emerging framework has paved the way for the development of a new class of small molecule "pharmacological chaperones" that bind to and stabilize misfolded MP variants, some of which are now in clinical use. In this review, we comprehensively outline current perspectives on the folding and misfolding of integral MPs as well as the mechanisms of cellular MP quality control. Based on these perspectives, we highlight new opportunities for innovations that bridge our molecular understanding of the energetics of MP folding with the nuanced complexity of biological systems. Given the many linkages between MP misfolding and human disease, we also examine some of the exciting opportunities to leverage these advances to address emerging challenges in the development of therapeutics and precision medicine.
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Affiliation(s)
- Justin
T. Marinko
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Hui Huang
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Wesley D. Penn
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - John A. Capra
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37245, United States
| | - Jonathan P. Schlebach
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Charles R. Sanders
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
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13
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Jouaud M, Mathis S, Richard L, Lia AS, Magy L, Vallat JM. Rodent models with expression of PMP22: Relevance to dysmyelinating CMT and HNPP. J Neurol Sci 2019; 398:79-90. [PMID: 30685714 DOI: 10.1016/j.jns.2019.01.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 12/26/2018] [Accepted: 01/16/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND Charcot-Marie-Tooth diseases (CMT) are due to abnormalities of many genes, the most frequent being linked to PMP22 (Peripheral Myelin Protein 22). In the past, only spontaneous genetic anomalies occurring in mouse mutants such as Trembler (Tr) mice were available; more recently, several rodent models have been generated for exploration of the pathophysiological mechanisms underlying these neuropathies. METHODS Based on the personal experience of our team, we describe here the pathological hallmarks of most of these animal models and compare them to the pathological features observed in some CMT patient nerves (CMT types 1A and E; hereditary neuropathy with liability to pressure palsies, HNPP). RESULTS We describe clinical data and detailed pathological analysis mainly by electron microscopy of the sciatic nerves of these animal models conducted in our laboratory; lesions of PMP22 deficient animals (KO and mutated PMP22) and PMP22 overexpressed models are described and compared to ultrastructural anomalies of nerve biopsies from CMT patients due to PMP22 gene anomalies. It is of note that while there are some similarities, there are also significant differences between the lesions in animal models and human cases. Such observations highlight the complex roles played by PMP22 in nerve development. CONCLUSION It should be borne in mind that we require additional correlations between animal models of hereditary neuropathies and CMT patients to rationalize the development of efficient drugs.
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Affiliation(s)
- Maxime Jouaud
- Equipe d'accueil 6309, Maintenance myélinique et Neuropathies périphériques, University of Limoges, 2 rue du Docteur Raymond Marcland, 87000 Limoges, France
| | - Stéphane Mathis
- Department of Neurology, Nerve-Muscle Unit, CHU Bordeaux (Pellegrin University Hospital), place Amélie Raba-Léon, 33000 Bordeaux, France; National Reference Center 'maladies neuromusculaires du Grand Sud-ouest', CHU Bordeaux (Pellegrin University Hospital), place Amélie Raba-Léon, 33000 Bordeaux, France
| | - Laurence Richard
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Anne-Sophie Lia
- Equipe d'accueil 6309, Maintenance myélinique et Neuropathies périphériques, University of Limoges, 2 rue du Docteur Raymond Marcland, 87000 Limoges, France; Department of Biochemistry and Molecular Genetics, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Laurent Magy
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France
| | - Jean-Michel Vallat
- Department of Neurology, CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France; National Reference Center for 'Rare Peripheral Neuropathies', CHU Limoges, Dupuytren University Hospital, 2 avenue Martin Luther King, 87042 Limoges, France.
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14
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Li LX, Dong HL, Xiao BG, Wu ZY. A Novel Missense Mutation in Peripheral Myelin Protein-22 Causes Charcot-Marie-Tooth Disease. Chin Med J (Engl) 2018; 130:1779-1784. [PMID: 28748849 PMCID: PMC5547828 DOI: 10.4103/0366-6999.211539] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background: Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral neuropathy. A great number of causative genes have been described in CMT, and among them, the heterozygous duplication of peripheral myelin protein-22 (PMP22) is the major cause. Although the missense mutation in PMP22 is rarely reported, it has been demonstrated to be associated with CMT. This study described a novel missense mutation of PMP22 in a Chinese family with CMT phenotype. Methods: Targeted next-generation sequencing (NGS) was used to screen the causative genes in a family featured with an autosomal dominant demyelinating form of CMT. The potential variants identified by targeted NGS were verified by Sanger sequencing and classified according to the American College of Medical Genetics and Genomics standards and guidelines. Further cell transfection studies were performed to characterize the function of the novel variant. Results: Using targeted NGS, a novel heterozygous missense variant in PMP22 (c.320G>A, p.G107D) was identified. In vitro cell functional studies revealed that mutant PMP22 protein carrying p.G107D mutation lost the ability to reach the plasma membrane, was mainly retained in the endoplasmic reticulum, and induced cell apoptosis. Conclusions: This study supported the notion that missense mutations in PMP22 give rise to a CMT phenotype, possibly through a toxic gain-of-function mechanism.
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Affiliation(s)
- Li-Xi Li
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Hai-Lin Dong
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, The Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Bao-Guo Xiao
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Zhi-Ying Wu
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
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15
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Zhang X, Li C, Fowler SC, Zhang Z, Blagg BSJ, Dobrowsky RT. Targeting Heat Shock Protein 70 to Ameliorate c-Jun Expression and Improve Demyelinating Neuropathy. ACS Chem Neurosci 2018; 9:381-390. [PMID: 29120605 DOI: 10.1021/acschemneuro.7b00377] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Increased expression of the c-jun transcription factor occurs in a variety of human neuropathies and is critical in promoting Schwann cell (SC) dedifferentiation and loss of the myelinated phenotype. Using cell culture models, we previously identified KU-32 as a novobiocin-based C-terminal heat shock protein 90 (Hsp90) inhibitor that decreased c-jun expression and the extent of demyelination. Additional chemical optimization has yielded KU-596 as a neuroprotective novologue whose mechanistic efficacy to improve a metabolic neuropathy requires the expression of Hsp70. The current study examined whether KU-596 therapy could decrease c-jun expression and improve motor function in an inducible transgenic model of a SC-specific demyelinating neuropathy (MPZ-Raf mice). Treating MPZ-Raf mice with tamoxifen activates the MAPK kinase pathway, increases c-jun expression and produces a profound demyelinating neuropathy characterized by a loss of motor function and paraparesis. KU-596 therapy did not interfere with MAPK activation but reduced c-jun expression, significantly improved motor performance, and ameliorated the extent of peripheral nerve demyelination in both prevention and intervention studies. Hsp70 was necessary for the drug's neuroprotective efficacy since MPZ-Raf × Hsp70 knockout mice did not respond to KU-596 therapy. Collectively, our data indicate that modulating Hsp70 may provide a novel therapeutic approach to attenuate SC c-jun expression and ameliorate the onset of certain demyelinating neuropathies in humans.
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Affiliation(s)
- Xinyue Zhang
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Chengyuan Li
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Stephen C. Fowler
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Zheng Zhang
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Brian S. J. Blagg
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Rick T. Dobrowsky
- Department
of Pharmacology and Toxicology and ‡Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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16
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Lee S, Bazick H, Chittoor-Vinod V, Al Salihi MO, Xia G, Notterpek L. Elevated Peripheral Myelin Protein 22, Reduced Mitotic Potential, and Proteasome Impairment in Dermal Fibroblasts from Charcot-Marie-Tooth Disease Type 1A Patients. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:728-738. [PMID: 29246495 PMCID: PMC5842032 DOI: 10.1016/j.ajpath.2017.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 10/05/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022]
Abstract
A common form of hereditary autosomal dominant demyelinating neuropathy known as Charcot-Marie-Tooth disease type 1A (CMT1A) is linked with duplication of the peripheral myelin protein 22 (PMP22) gene. Although studies from animal models have led to better understanding of the pathobiology of these neuropathies, there continues to be a gap in the translation of findings from rodents to humans. Because PMP22 was originally identified in fibroblasts as growth arrest specific gene 3 (gas3) and is expressed broadly in the body, it was tested whether skin cells from neuropathic patients would display the cellular pathology observed in Schwann cells from rodent models. Dermal fibroblasts from two CMT1A pedigrees with confirmed PMP22 gene duplication were studied. Samples from age-matched non-neuropathic individuals were used as controls. CMT1A patient–derived cultures contain approximately 1.5-fold elevated levels of PMP22 mRNA, exhibit reduced mitotic potential, and display intracellular protein aggregates as compared to cells from unaffected individuals. The presence of cytosolic PMP22 coincides with a decrease in proteasome activity and an increase in autophagy-lysosomal proteins, including LC3-II and LAMP1. These results indicate that the abnormalities in the subcellular processing of excess PMP22 elicit a detectable response in human CMT1A fibroblasts, a phenotype that resembles Schwann cells from neuropathic mice. These findings support the use of human CMT1A fibroblasts as a platform for therapy testing.
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Affiliation(s)
- Sooyeon Lee
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Hannah Bazick
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Vinita Chittoor-Vinod
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Mohammed Omar Al Salihi
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida
| | - Guangbin Xia
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida; Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida.
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17
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Abstract
The chaperome constitutes a broad family of molecular chaperones and co-chaperones that facilitate the folding, refolding, and degradation of the proteome. Heat shock protein 90 (Hsp90) promotes the folding of numerous oncoproteins to aid survival of malignant phenotypes, and small molecule inhibitors of the Hsp90 chaperone complex offer a viable approach to treat certain cancers. One therapeutic attribute of this approach is the selectivity of these molecules to target high affinity oncogenic Hsp90 complexes present in tumor cells, which are absent in nontransformed cells. This selectivity has given rise to the idea that disease may contribute to forming a stress chaperome that is functionally distinct in its ability to interact with small molecule Hsp90 modulators. Consistent with this premise, modulating Hsp90 improves clinically relevant endpoints of diabetic peripheral neuropathy but has little impact in nondiabetic nerve. The concept of targeting the "diabetic chaperome" to treat diabetes and its complications is discussed.
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Affiliation(s)
- Rick T Dobrowsky
- Department of Pharmacology and Toxicology, The University of Kansas, 5064 Malott Hall 1251 Wescoe Hall Dr., Lawrence, KS, 66045, USA.
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18
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Zhou Y, Notterpek L. Promoting peripheral myelin repair. Exp Neurol 2016; 283:573-80. [PMID: 27079997 DOI: 10.1016/j.expneurol.2016.04.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/30/2016] [Accepted: 04/06/2016] [Indexed: 01/08/2023]
Abstract
Compared to the central nervous system (CNS), peripheral nerves have a remarkable ability to regenerate and remyelinate. This regenerative capacity to a large extent is dependent on and supported by Schwann cells, the myelin-forming glial cells of the peripheral nervous system (PNS). In a variety of paradigms, Schwann cells are critical in the removal of the degenerated tissue, which is followed by remyelination of newly-regenerated axons. This unique plasticity of Schwann cells has been the target of myelin repair strategies in acute injuries and chronic diseases, such as hereditary demyelinating neuropathies. In one approach, the endogenous regenerative capacity of Schwann cells is enhanced through interventions such as exercise, electrical stimulation or pharmacological means. Alternatively, Schwann cells derived from healthy nerves, or engineered from different tissue sources have been transplanted into the PNS to support remyelination. These transplant approaches can then be further enhanced by exercise and/or electrical stimulation, as well as by the inclusion of biomaterial engineered to support glial cell viability and neurite extension. Advances in our basic understanding of peripheral nerve biology, as well as biomaterial engineering, will further improve the functional repair of myelinated peripheral nerves.
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Affiliation(s)
- Ye Zhou
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, United States
| | - Lucia Notterpek
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, United States.
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19
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Emery SM, Dobrowsky RT. Promoting Neuronal Tolerance of Diabetic Stress: Modulating Molecular Chaperones. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 127:181-210. [PMID: 27133150 DOI: 10.1016/bs.irn.2016.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The etiology of diabetic peripheral neuropathy (DPN) involves an interrelated series of metabolic and vascular insults that ultimately contribute to sensory neuron degeneration. In the quest to pharmacologically manage DPN, small-molecule inhibitors have targeted proteins and pathways regarded as "diabetes specific" as well as others whose activity are altered in numerous disease states. These efforts have not yielded any significant therapies, due in part to the complicating issue that the biochemical contribution of these targets/pathways to the progression of DPN does not occur with temporal and/or biochemical uniformity between individuals. In a complex, chronic neurodegenerative disease such as DPN, it is increasingly appreciated that effective disease management may not necessarily require targeting a pathway or protein considered to contribute to disease progression. Alternatively, it may prove sufficiently beneficial to pharmacologically enhance the activity of endogenous cytoprotective pathways to aid neuronal tolerance to and recovery from glucotoxic stress. In pursuing this paradigm shift, we have shown that modulating the activity and expression of molecular chaperones such as heat shock protein 70 (Hsp70) may provide translational potential for the effective medical management of insensate DPN. Considerable evidence supports that modulating Hsp70 has beneficial effects in improving inflammation, oxidative stress, and glucose sensitivity. Given the emerging potential of modulating Hsp70 to manage DPN, the current review discusses efforts to characterize the cytoprotective effects of this protein and the benefits and limitations that may arise in drug development efforts that exploit its cytoprotective activity.
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Affiliation(s)
- S M Emery
- The University of Kansas, Lawrence, KS, United States
| | - R T Dobrowsky
- The University of Kansas, Lawrence, KS, United States.
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20
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Gonzalez S, Berthelot J, Jiner J, Perrin-Tricaud C, Fernando R, Chrast R, Lenaers G, Tricaud N. Blocking mitochondrial calcium release in Schwann cells prevents demyelinating neuropathies. J Clin Invest 2016; 126:1023-38. [PMID: 26878172 DOI: 10.1172/jci84505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/18/2015] [Indexed: 02/06/2023] Open
Abstract
Schwann cells produce myelin sheath around peripheral nerve axons. Myelination is critical for rapid propagation of action potentials, as illustrated by the large number of acquired and hereditary peripheral neuropathies, such as diabetic neuropathy or Charcot-Marie-Tooth diseases, that are commonly associated with a process of demyelination. However, the early molecular events that trigger the demyelination program in these diseases remain unknown. Here, we used virally delivered fluorescent probes and in vivo time-lapse imaging in a mouse model of demyelination to investigate the underlying mechanisms of the demyelination process. We demonstrated that mitochondrial calcium released by voltage-dependent anion channel 1 (VDAC1) after sciatic nerve injury triggers Schwann cell demyelination via ERK1/2, p38, JNK, and c-JUN activation. In diabetic mice, VDAC1 activity was altered, resulting in a mitochondrial calcium leak in Schwann cell cytoplasm, thereby priming the cell for demyelination. Moreover, reduction of mitochondrial calcium release, either by shRNA-mediated VDAC1 silencing or pharmacological inhibition, prevented demyelination, leading to nerve conduction and neuromuscular performance recovery in rodent models of diabetic neuropathy and Charcot-Marie-Tooth diseases. Therefore, this study identifies mitochondria as the early key factor in the molecular mechanism of peripheral demyelination and opens a potential opportunity for the treatment of demyelinating peripheral neuropathies.
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21
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Ma J, Pan P, Anyika M, Blagg BSJ, Dobrowsky RT. Modulating Molecular Chaperones Improves Mitochondrial Bioenergetics and Decreases the Inflammatory Transcriptome in Diabetic Sensory Neurons. ACS Chem Neurosci 2015; 6:1637-48. [PMID: 26161583 DOI: 10.1021/acschemneuro.5b00165] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have previously demonstrated that modulating molecular chaperones with KU-32, a novobiocin derivative, ameliorates physiologic and bioenergetic deficits of diabetic peripheral neuropathy (DPN). Replacing the coumarin core of KU-32 with a meta-fluorinated biphenyl ring system created KU-596, a novobiocin analogue (novologue) that showed neuroprotective activity in a cell-based assay. The current study sought to determine whether KU-596 offers similar therapeutic potential for treating DPN. Administration of 2-20 mg/kg of KU-596 improved diabetes induced hypoalgesia and sensory neuron bioenergetic deficits in a dose-dependent manner. However, the drug could not improve these neuropathic deficits in diabetic heat shock protein 70 knockout (Hsp70 KO) mice. To gain further insight into the mechanisms by which KU-596 improved DPN, we performed transcriptomic analysis of sensory neuron RNA obtained from diabetic wild-type and Hsp70 KO mice using RNA sequencing. Bioinformatic analysis of the differentially expressed genes indicated that diabetes strongly increased inflammatory pathways and that KU-596 therapy effectively reversed these increases independent of Hsp70. In contrast, the effects of KU-596 on decreasing the expression of genes regulating the production of reactive oxygen species were more Hsp70-dependent. These data indicate that modulation of molecular chaperones by novologue therapy offers an effective approach toward correcting nerve dysfunction in DPN but that normalization of inflammatory pathways alone by novologue therapy seems to be insufficient to reverse sensory deficits associated with insensate DPN.
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Affiliation(s)
- Jiacheng Ma
- Department of Pharmacology and Toxicology and ‡̂Department
of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Pan Pan
- Department of Pharmacology and Toxicology and ‡̂Department
of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Mercy Anyika
- Department of Pharmacology and Toxicology and ‡̂Department
of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Brian S. J. Blagg
- Department of Pharmacology and Toxicology and ‡̂Department
of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Rick T. Dobrowsky
- Department of Pharmacology and Toxicology and ‡̂Department
of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States
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22
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Ekins S, Litterman NK, Arnold RJG, Burgess RW, Freundlich JS, Gray SJ, Higgins JJ, Langley B, Willis DE, Notterpek L, Pleasure D, Sereda MW, Moore A. A brief review of recent Charcot-Marie-Tooth research and priorities. F1000Res 2015; 4:53. [PMID: 25901280 PMCID: PMC4392824 DOI: 10.12688/f1000research.6160.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2015] [Indexed: 12/14/2022] Open
Abstract
This brief review of current research progress on Charcot-Marie-Tooth (CMT) disease is a summary of discussions initiated at the Hereditary Neuropathy Foundation (HNF) scientific advisory board meeting on November 7, 2014. It covers recent published and unpublished
in vitro and
in vivo research. We discuss recent promising preclinical work for CMT1A, the development of new biomarkers, the characterization of different animal models, and the analysis of the frequency of gene mutations in patients with CMT. We also describe how progress in related fields may benefit CMT therapeutic development, including the potential of gene therapy and stem cell research. We also discuss the potential to assess and improve the quality of life of CMT patients. This summary of CMT research identifies some of the gaps which may have an impact on upcoming clinical trials. We provide some priorities for CMT research and areas which HNF can support. The goal of this review is to inform the scientific community about ongoing research and to avoid unnecessary overlap, while also highlighting areas ripe for further investigation. The general collaborative approach we have taken may be useful for other rare neurological diseases.
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Affiliation(s)
- Sean Ekins
- Hereditary Neuropathy Foundation, New York, NY, 10016, USA ; Collaborations in Chemistry, Fuquay Varina, NC, 27526, USA ; Collaborative Drug Discovery, Burlingame, CA, 94010, USA
| | | | - Renée J G Arnold
- Arnold Consultancy & Technology LLC, New York, NY, 10023, USA ; Master of Public Health Program, Mount Sinai School of Medicine, New York, NY, 10029, USA ; Quorum Consulting, Inc, San Francisco, CA, 94104, USA
| | - Robert W Burgess
- The Jackson Laboratory in Bar Harbor, Bar Harbour, ME, 04609, USA
| | - Joel S Freundlich
- Department of Medicine, Center for Emerging and Reemerging Pathogens, Rutgers University - New Jersey Medical School, Newark, NJ, 07103, USA
| | - Steven J Gray
- Gene Therapy Center and Dept. of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7352, USA
| | | | - Brett Langley
- Burke-Cornell Medical Research Institute, White Plains, NY, 10605, USA ; Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Dianna E Willis
- Burke-Cornell Medical Research Institute, White Plains, NY, 10605, USA
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL, 32611, USA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, University of California Davis, School of Medicine, Sacramento, CA, 95817, USA ; Department of Neurology, University of California, Davis, School of Medicine, c/o Shriners Hospital, Sacramento, CA, 95817, USA
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute (MPI) of Experimental Medicine, Göttingen, 37075, Germany ; Department of Clinical Neurophysiology, University Medical Center (UMG), Göttingen, D-37075, Germany
| | - Allison Moore
- Hereditary Neuropathy Foundation, New York, NY, 10016, USA
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