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Xin J, Huang S, Wen J, Li Y, Li A, Satyanarayanan SK, Yao X, Su H. Drug Screening and Validation Targeting TDP-43 Proteinopathy for Amyotrophic Lateral Sclerosis. Aging Dis 2024:AD.2024.0440. [PMID: 38739934 DOI: 10.14336/ad.2024.0440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/05/2024] [Indexed: 05/16/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) stands as a rare, yet severely debilitating disorder marked by the deterioration of motor neurons (MNs) within the brain and spinal cord, which is accompanied by degenerated corticobulbar/corticospinal tracts and denervation in skeletal muscles. Despite ongoing research efforts, ALS remains incurable, attributed to its intricate pathogenic mechanisms. A notable feature in the pathology of ALS is the prevalence of TAR DNA-binding protein 43 (TDP-43) proteinopathy, detected in approximately 97% of ALS cases, underscoring its significance in the disease's progression. As a result, strategies targeting the aberrant TDP-43 protein have garnered attention as a potential avenue for ALS therapy. This review delves into the existing drug screening systems aimed at TDP-43 proteinopathy and the models employed for drug efficacy validation. It also explores the hurdles encountered in the quest to develop potent medications against TDP-43 proteinopathy, offering insights into the intricacies of drug discovery and development for ALS. Through this comprehensive analysis, the review sheds light on the critical aspects of identifying and advancing therapeutic solutions for ALS.
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Affiliation(s)
- Jiaqi Xin
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Sen Huang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University; Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases; National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Jing Wen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Yunhao Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Ang Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Senthil Kumaran Satyanarayanan
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Hong Kong Science Park, Hong Kong, China
| | - Xiaoli Yao
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University; Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases; National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
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2
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Lo Piccolo L, Umegawachi T, Yeewa R, Potikanond S, Nimlamool W, Prachayasittikul V, Gotoh Y, Yoshida H, Yamaguchi M, Jantrapirom S. A Novel Drosophila-based Drug Repurposing Platform Identified Fingolimod As a Potential Therapeutic for TDP-43 Proteinopathy. Neurotherapeutics 2023; 20:1330-1346. [PMID: 37493896 PMCID: PMC10480388 DOI: 10.1007/s13311-023-01406-z] [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] [Accepted: 06/26/2023] [Indexed: 07/27/2023] Open
Abstract
Pathogenic changes to TAR DNA-binding protein 43 (TDP-43) leading to alteration of its homeostasis are a common feature shared by several progressive neurodegenerative diseases for which there is no effective therapy. Here, we developed Drosophila lines expressing either wild type TDP-43 (WT) or that carrying an Amyotrophic Lateral Sclerosis /Frontotemporal Lobar Degeneration-associating G384C mutation that recapitulate several aspects of the TDP-43 pathology. To identify potential therapeutics for TDP-43-related diseases, we implemented a drug repurposing strategy that involved three consecutive steps. Firstly, we evaluated the improvement of eclosion rate, followed by the assessment of locomotive functions at early and late developmental stages. Through this approach, we successfully identified fingolimod, as a promising candidate for modulating TDP-43 toxicity. Fingolimod exhibited several beneficial effects in both WT and mutant models of TDP-43 pathology, including post-transcriptional reduction of TDP-43 levels, rescue of pupal lethality, and improvement of locomotor dysfunctions. These findings provide compelling evidence for the therapeutic potential of fingolimod in addressing TDP-43 pathology, thereby strengthening the rationale for further investigation and consideration of clinical trials. Furthermore, our study demonstrates the utility of our Drosophila-based screening pipeline in identifying novel therapeutics for TDP-43-related diseases. These findings encourage further scale-up screening endeavors using this platform to discover additional compounds with therapeutic potential for TDP-43 pathology.
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Affiliation(s)
- Luca Lo Piccolo
- Center of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Faculty of Medicine, Musculoskeletal Science and Translational Research Centre (MSTR), Chiang Mai University, Chiang Mai, Thailand
| | | | - Ranchana Yeewa
- Center of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Saranyapin Potikanond
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wutigri Nimlamool
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Virapong Prachayasittikul
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Chiang Mai, Thailand
| | - Yusuke Gotoh
- Platform Technology Research Unit, Sumitomo Pharma Co., Ltd, Kyoto, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | | | - Salinee Jantrapirom
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
- Drosophila Centre for Human Diseases and Drug Discovery (DHD), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
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Lobanov SV, McAllister B, McDade-Kumar M, Landwehrmeyer GB, Orth M, Rosser AE, Paulsen JS, Lee JM, MacDonald ME, Gusella JF, Long JD, Ryten M, Williams NM, Holmans P, Massey TH, Jones L. Huntington's disease age at motor onset is modified by the tandem hexamer repeat in TCERG1. NPJ Genom Med 2022; 7:53. [PMID: 36064847 PMCID: PMC9445028 DOI: 10.1038/s41525-022-00317-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 07/15/2022] [Indexed: 01/29/2023] Open
Abstract
Huntington's disease is caused by an expanded CAG tract in HTT. The length of the CAG tract accounts for over half the variance in age at onset of disease, and is influenced by other genetic factors, mostly implicating the DNA maintenance machinery. We examined a single nucleotide variant, rs79727797, on chromosome 5 in the TCERG1 gene, previously reported to be associated with Huntington's disease and a quasi-tandem repeat (QTR) hexamer in exon 4 of TCERG1 with a central pure repeat. We developed a method for calling perfect and imperfect repeats from exome-sequencing data, and tested association between the QTR in TCERG1 and residual age at motor onset (after correcting for the effects of CAG length in the HTT gene) in 610 individuals with Huntington's disease via regression analysis. We found a significant association between age at onset and the sum of the repeat lengths from both alleles of the QTR (p = 2.1 × 10-9), with each added repeat hexamer reducing age at onset by one year (95% confidence interval [0.7, 1.4]). This association explained that previously observed with rs79727797. The association with age at onset in the genome-wide association study is due to a QTR hexamer in TCERG1, translated to a glutamine/alanine tract in the protein. We could not distinguish whether this was due to cis-effects of the hexamer repeat on gene expression or of the encoded glutamine/alanine tract in the protein. These results motivate further study of the mechanisms by which TCERG1 modifies onset of HD.
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Affiliation(s)
- Sergey V Lobanov
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Branduff McAllister
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Mia McDade-Kumar
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | | | - Michael Orth
- Department of Old Age Psychiatry and Psychotherapy, Bern University, Bern, Switzerland
- Swiss Huntington's Disease Centre, Siloah, Gümligen, Switzerland
| | - Anne E Rosser
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
| | - Jane S Paulsen
- Department of Neurology, University of Wisconsin, Madison, WI53705, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Jeffrey D Long
- Departments of Psychiatry and Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Mina Ryten
- Great Ormond Street Institute of Child Health, Genetics and Genomic Medicine, University, College London, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
| | - Nigel M Williams
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Peter Holmans
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
| | - Thomas H Massey
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.
| | - Lesley Jones
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK
- UK Dementia Research Institute at Cardiff, Cardiff University, Cardiff, UK
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4
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François-Moutal L, Scott DD, Ambrose AJ, Zerio CJ, Rodriguez-Sanchez M, Dissanayake K, May DG, Carlson JM, Barbieri E, Moutal A, Roux KJ, Shorter J, Khanna R, Barmada SJ, McGurk L, Khanna M. Heat shock protein Grp78/BiP/HspA5 binds directly to TDP-43 and mitigates toxicity associated with disease pathology. Sci Rep 2022; 12:8140. [PMID: 35581326 PMCID: PMC9114370 DOI: 10.1038/s41598-022-12191-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/04/2022] [Indexed: 11/09/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with no cure or effective treatment in which TAR DNA Binding Protein of 43 kDa (TDP-43) abnormally accumulates into misfolded protein aggregates in affected neurons. It is widely accepted that protein misfolding and aggregation promotes proteotoxic stress. The molecular chaperones are a primary line of defense against proteotoxic stress, and there has been long-standing interest in understanding the relationship between chaperones and aggregated protein in ALS. Of particular interest are the heat shock protein of 70 kDa (Hsp70) family of chaperones. However, defining which of the 13 human Hsp70 isoforms is critical for ALS has presented many challenges. To gain insight into the specific Hsp70 that modulates TDP-43, we investigated the relationship between TDP-43 and the Hsp70s using proximity-dependent biotin identification (BioID) and discovered several Hsp70 isoforms associated with TDP-43 in the nucleus, raising the possibility of an interaction with native TDP-43. We further found that HspA5 bound specifically to the RNA-binding domain of TDP-43 using recombinantly expressed proteins. Moreover, in a Drosophila strain that mimics ALS upon TDP-43 expression, the mRNA levels of the HspA5 homologue (Hsc70.3) were significantly increased. Similarly we observed upregulation of HspA5 in prefrontal cortex neurons from human ALS patients. Finally, overexpression of HspA5 in Drosophila rescued TDP-43-induced toxicity, suggesting that upregulation of HspA5 may have a compensatory role in ALS pathobiology.
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Affiliation(s)
- Liberty François-Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA.,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA
| | - David Donald Scott
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA.,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA
| | - Andrew J Ambrose
- Pharmacology and Toxicology, School of Pharmacy, University of Arizona, Tucson, AZ, 85724, USA
| | - Christopher J Zerio
- Pharmacology and Toxicology, School of Pharmacy, University of Arizona, Tucson, AZ, 85724, USA
| | | | - Kumara Dissanayake
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Danielle G May
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA
| | - Jacob M Carlson
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA.,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA
| | - Edward Barbieri
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA.,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA
| | - Kyle J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA.,Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
| | - James Shorter
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA.,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Leeanne McGurk
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - May Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, 85724, USA. .,Center for Innovation in Brain Science, Tucson, AZ, 85721, USA. .,Department of Molecular Pathobiology, NYU, New York, NY, USA. .,Department of Molecular Pathobiology, College of Dentistry, NYU, 433 1st Ave, New York, NY, 10010, USA.
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5
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McAlary L, Chew YL, Lum JS, Geraghty NJ, Yerbury JJ, Cashman NR. Amyotrophic Lateral Sclerosis: Proteins, Proteostasis, Prions, and Promises. Front Cell Neurosci 2020; 14:581907. [PMID: 33328890 PMCID: PMC7671971 DOI: 10.3389/fncel.2020.581907] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of the motor neurons that innervate muscle, resulting in gradual paralysis and culminating in the inability to breathe or swallow. This neuronal degeneration occurs in a spatiotemporal manner from a point of onset in the central nervous system (CNS), suggesting that there is a molecule that spreads from cell-to-cell. There is strong evidence that the onset and progression of ALS pathology is a consequence of protein misfolding and aggregation. In line with this, a hallmark pathology of ALS is protein deposition and inclusion formation within motor neurons and surrounding glia of the proteins TAR DNA-binding protein 43, superoxide dismutase-1, or fused in sarcoma. Collectively, the observed protein aggregation, in conjunction with the spatiotemporal spread of symptoms, strongly suggests a prion-like propagation of protein aggregation occurs in ALS. In this review, we discuss the role of protein aggregation in ALS concerning protein homeostasis (proteostasis) mechanisms and prion-like propagation. Furthermore, we examine the experimental models used to investigate these processes, including in vitro assays, cultured cells, invertebrate models, and murine models. Finally, we evaluate the therapeutics that may best prevent the onset or spread of pathology in ALS and discuss what lies on the horizon for treating this currently incurable disease.
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Affiliation(s)
- Luke McAlary
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Yee Lian Chew
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Jeremy Stephen Lum
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Nicholas John Geraghty
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Justin John Yerbury
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Neil R. Cashman
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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Liscic RM, Alberici A, Cairns NJ, Romano M, Buratti E. From basic research to the clinic: innovative therapies for ALS and FTD in the pipeline. Mol Neurodegener 2020; 15:31. [PMID: 32487123 PMCID: PMC7268618 DOI: 10.1186/s13024-020-00373-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/27/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and Frontotemporal Degeneration (FTD) are neurodegenerative disorders, related by deterioration of motor and cognitive functions and short survival. Aside from cases with an inherited pathogenic mutation, the causes of the disorders are still largely unknown and no effective treatment currently exists. It has been shown that FTD may coexist with ALS and this overlap occurs at clinical, genetic, and molecular levels. In this work, we review the main pathological aspects of these complex diseases and discuss how the integration of the novel pathogenic molecular insights and the analysis of molecular interaction networks among all the genetic players represents a critical step to shed light on discovering novel therapeutic strategies and possibly tailoring personalized medicine approaches to specific ALS and FTD patients.
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Affiliation(s)
- Rajka Maria Liscic
- Department of Neurology, Johannes Kepler University, Linz, Austria
- School of Medicine, University of Osijek, Osijek, Croatia
| | - Antonella Alberici
- Neurology Unit, Department of Neurological Sciences and Vision, ASST-Spedali Civili-University of Brescia, Brescia, Italy
| | - Nigel John Cairns
- College of Medicine and Health and Living Systems Institute, University of Exeter, Exeter, UK
| | - Maurizio Romano
- Department of Life Sciences, Via Valerio 28, University of Trieste, 34127, Trieste, Italy
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, 34149, Trieste, Italy.
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7
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Liachko NF, Saxton AD, McMillan PJ, Strovas TJ, Keene CD, Bird TD, Kraemer BC. Genome wide analysis reveals heparan sulfate epimerase modulates TDP-43 proteinopathy. PLoS Genet 2019; 15:e1008526. [PMID: 31834878 PMCID: PMC6934317 DOI: 10.1371/journal.pgen.1008526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 12/27/2019] [Accepted: 11/15/2019] [Indexed: 12/31/2022] Open
Abstract
Pathological phosphorylated TDP-43 protein (pTDP) deposition drives neurodegeneration in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP). However, the cellular and genetic mechanisms at work in pathological TDP-43 toxicity are not fully elucidated. To identify genetic modifiers of TDP-43 neurotoxicity, we utilized a Caenorhabditis elegans model of TDP-43 proteinopathy expressing human mutant TDP-43 pan-neuronally (TDP-43 tg). In TDP-43 tg C. elegans, we conducted a genome-wide RNAi screen covering 16,767 C. elegans genes for loss of function genetic suppressors of TDP-43-driven motor dysfunction. We identified 46 candidate genes that when knocked down partially ameliorate TDP-43 related phenotypes; 24 of these candidate genes have conserved homologs in the human genome. To rigorously validate the RNAi findings, we crossed the TDP-43 transgene into the background of homozygous strong genetic loss of function mutations. We have confirmed 9 of the 24 candidate genes significantly modulate TDP-43 transgenic phenotypes. Among the validated genes we focused on, one of the most consistent genetic modifier genes protecting against pTDP accumulation and motor deficits was the heparan sulfate-modifying enzyme hse-5, the C. elegans homolog of glucuronic acid epimerase (GLCE). We found that knockdown of human GLCE in cultured human cells protects against oxidative stress induced pTDP accumulation. Furthermore, expression of glucuronic acid epimerase is significantly decreased in the brains of FTLD-TDP cases relative to normal controls, demonstrating the potential disease relevance of the candidate genes identified. Taken together these findings nominate glucuronic acid epimerase as a novel candidate therapeutic target for TDP-43 proteinopathies including ALS and FTLD-TDP. The protein TDP-43 forms aggregates in disease-affected neurons in patients with ALS and FTLD-TDP. In addition, mutations in the human gene coding for TDP-43 can cause inherited ALS. By expressing human mutant TDP-43 protein in C. elegans neurons, we have modelled aspects of ALS pathobiology. This animal model exhibits severe motor dysfunction, progressive neurodegeneration, and accumulation of abnormally modified TDP-43 protein. To identify genes controlling TDP-43 neurotoxicity in C. elegans, we have conducted a genome-wide reverse genetic screen and found 46 genes that participate in TDP-43 neurotoxicity. We demonstrated that one of them, glucuronic acid epimerase, is decreased in patients with FTLD-TDP suggesting inhibitors of glucuronic acid epimerase could have therapeutic value for ALS and FTLD.
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Affiliation(s)
- Nicole F. Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Aleen D. Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
| | - Pamela J. McMillan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
| | - Timothy J. Strovas
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
| | - C. Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Thomas D. Bird
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Brian C. Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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8
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Cortini A, Bembich S, Marson L, Cocco E, Edomi P. Identification of novel non-myelin biomarkers in multiple sclerosis using an improved phage-display approach. PLoS One 2019; 14:e0226162. [PMID: 31805175 PMCID: PMC6894809 DOI: 10.1371/journal.pone.0226162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/20/2019] [Indexed: 12/17/2022] Open
Abstract
Although the etiology of multiple sclerosis is not yet understood, it is accepted that its pathogenesis involves both autoimmune and neurodegenerative processes, in which the role of autoreactive T-cells has been elucidated. Instead, the contribution of humoral response is still unclear, even if the presence of intrathecal antibodies and B-cells follicle-like structures in meninges of patients has been demonstrated. Several myelin and non-myelin antigens have been identified, but none has been validated as humoral biomarker. In particular autoantibodies against myelin proteins have been found also in healthy individuals, whereas non-myelin antigens have been implicated in neurodegenerative phase of the disease. To provide further putative autoantigens of multiple sclerosis, we investigated the antigen specificity of immunoglobulins present both in sera and in cerebrospinal fluid of patients using phage display technology in a new improved format. A human brain cDNA phage display library was constructed and enriched for open-read-frame fragments. This library was selected against pooled and purified immunoglobulins from cerebrospinal fluid and sera of multiple sclerosis patients. The antigen library was also screened against an antibody scFv library obtained from RNA of B cells purified from the cerebrospinal fluid of two relapsing remitting patients. From all biopanning a complex of 14 antigens were identified; in particular, one of these antigens, corresponding to DDX24 protein, was present in all selections. The ability of more frequently isolated antigens to discriminate between sera from patients with multiple sclerosis or other neurological diseases was investigated. The more promising novel candidate autoantigens were DDX24 and TCERG1. Both are implicated in RNA modification and regulation which can be altered in neurodegenerative processes. Therefore, we propose that they could be a marker of a particular disease activity state.
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Affiliation(s)
- Andrea Cortini
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Sara Bembich
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Lorena Marson
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Eleonora Cocco
- Multiple Sclerosis Center, University of Cagliari/ATS Sardegna, Cagliari, Italy
| | - Paolo Edomi
- Department of Life Sciences, University of Trieste, Trieste, Italy
- * E-mail:
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