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Marriott H, Kabiljo R, Hunt GP, Khleifat AA, Jones A, Troakes C, Pfaff AL, Quinn JP, Koks S, Dobson RJ, Schwab P, Al-Chalabi A, Iacoangeli A. Unsupervised machine learning identifies distinct ALS molecular subtypes in post-mortem motor cortex and blood expression data. Acta Neuropathol Commun 2023; 11:208. [PMID: 38129934 PMCID: PMC10734072 DOI: 10.1186/s40478-023-01686-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/10/2023] [Indexed: 12/23/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) displays considerable clinical and genetic heterogeneity. Machine learning approaches have previously been utilised for patient stratification in ALS as they can disentangle complex disease landscapes. However, lack of independent validation in different populations and tissue samples have greatly limited their use in clinical and research settings. We overcame these issues by performing hierarchical clustering on the 5000 most variably expressed autosomal genes from motor cortex expression data of people with sporadic ALS from the KCL BrainBank (N = 112). Three molecular phenotypes linked to ALS pathogenesis were identified: synaptic and neuropeptide signalling, oxidative stress and apoptosis, and neuroinflammation. Cluster validation was achieved by applying linear discriminant analysis models to cases from TargetALS US motor cortex (N = 93), as well as Italian (N = 15) and Dutch (N = 397) blood expression datasets, for which there was a high assignment probability (80-90%) for each molecular subtype. The ALS and motor cortex specificity of the expression signatures were tested by mapping KCL BrainBank controls (N = 59), and occipital cortex (N = 45) and cerebellum (N = 123) samples from TargetALS to each cluster, before constructing case-control and motor cortex-region logistic regression classifiers. We found that the signatures were not only able to distinguish people with ALS from controls (AUC 0.88 ± 0.10), but also reflect the motor cortex-based disease process, as there was perfect discrimination between motor cortex and the other brain regions. Cell types known to be involved in the biological processes of each molecular phenotype were found in higher proportions, reinforcing their biological interpretation. Phenotype analysis revealed distinct cluster-related outcomes in both motor cortex datasets, relating to disease onset and progression-related measures. Our results support the hypothesis that different mechanisms underpin ALS pathogenesis in subgroups of patients and demonstrate potential for the development of personalised treatment approaches. Our method is available for the scientific and clinical community at https://alsgeclustering.er.kcl.ac.uk .
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Affiliation(s)
- Heather Marriott
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Renata Kabiljo
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Guy P Hunt
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA, 6150, Australia
| | - Ahmad Al Khleifat
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
| | - Ashley Jones
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
| | - Claire Troakes
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
- MRC London Neurodegenerative Diseases Brain Bank, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Abigail L Pfaff
- Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA, 6150, Australia
| | - John P Quinn
- Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 3BX, UK
| | - Sulev Koks
- Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA, 6150, Australia
| | - Richard J Dobson
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- NIHR Maudsley Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust and King's College London, London, UK
- Institute of Health Informatics, University College London, London, UK
- NIHR Biomedical Research Centre, University College London Hospitals NHS Foundation Trust, London, UK
| | - Patrick Schwab
- GlaxoSmithKline, Artificial Intelligence and Machine Learning, Durham, NC, USA
| | - Ammar Al-Chalabi
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK
- King's College Hospital, London, SE5 9RS, UK
| | - Alfredo Iacoangeli
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King?s College London, London, SE5 9NU, UK.
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
- NIHR Maudsley Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust and King's College London, London, UK.
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Eisen A, Vucic S, Mitsumoto H. History of ALS and the competing theories on pathogenesis: IFCN handbook chapter. Clin Neurophysiol Pract 2023; 9:1-12. [PMID: 38213309 PMCID: PMC10776891 DOI: 10.1016/j.cnp.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/07/2023] [Accepted: 11/28/2023] [Indexed: 01/13/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the human motor system, first described in the 19th Century. The etiology of ALS appears to be multifactorial, with a complex interaction of genetic, epigenetic, and environmental factors underlying the onset of disease. Importantly, there are no known naturally occurring animal models, and transgenic mouse models fail to faithfully reproduce ALS as it manifests in patients. Debate as to the site of onset of ALS remain, with three competing theories proposed, including (i) the dying-forward hypothesis, whereby motor neuron degeneration is mediated by hyperexcitable corticomotoneurons via an anterograde transsynaptic excitotoxic mechanism, (ii) dying-back hypothesis, proposing the ALS begins in the peripheral nervous system with a toxic factor(s) retrogradely transported into the central nervous system and mediating upper motor neuron dysfunction, and (iii) independent hypothesis, suggesting that upper and lower motor neuron degenerated independently. Transcranial magnetic stimulation studies, along with pathological and genetic findings have supported the dying forward hypothesis theory, although the science is yet to be settled. The review provides a historical overview of ALS, discusses phenotypes and likely pathogenic mechanisms.
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Affiliation(s)
- Andrew Eisen
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
| | - Steve Vucic
- Director Brain and Nerve Research Center, Clinical School, University of Sydney, Australia
| | - Hiroshi Mitsumoto
- Wesley J. Howe Professor of Neurology, Columbia University, The Neurological Institute of New York, and New York-Presbyterian Hospital/Columbia University Medical Center, United States
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Genç B, Nho B, Seung H, Helmold B, Park H, Gözütok Ö, Kim S, Park J, Ye S, Lee H, Lee N, Yu SS, Kim S, Lee J, Özdinler H. Novel rAAV vector mediated intrathecal HGF delivery has an impact on neuroimmune modulation in the ALS motor cortex with TDP-43 pathology. Gene Ther 2023; 30:560-574. [PMID: 36823441 DOI: 10.1038/s41434-023-00383-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/21/2022] [Accepted: 01/23/2023] [Indexed: 02/25/2023]
Abstract
Recombinant adeno-associated virus (rAAV)-based gene therapies offer an immense opportunity for rare diseases, such as amyotrophic lateral sclerosis (ALS), which is defined by the loss of the upper and the lower motor neurons. Here, we describe generation, characterization, and utilization of a novel vector system, which enables expression of the active form of hepatocyte growth factor (HGF) under EF-1α promoter with bovine growth hormone (bGH) poly(A) sequence and is effective with intrathecal injections. HGF's role in promoting motor neuron survival had been vastly reported. Therefore, we investigated whether intrathecal delivery of HGF would have an impact on one of the most common pathologies of ALS: the TDP-43 pathology. Increased astrogliosis, microgliosis and progressive upper motor neuron loss are important consequences of ALS in the motor cortex with TDP-43 pathology. We find that cortex can be modulated via intrathecal injection, and that expression of HGF reduces astrogliosis, microgliosis in the motor cortex, and help restore ongoing UMN degeneration. Our findings not only introduce a novel viral vector for the treatment of ALS, but also demonstrate modulation of motor cortex by intrathecal viral delivery, and that HGF treatment is effective in reducing astrogliosis and microgliosis in the motor cortex of ALS with TDP-43 pathology.
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Affiliation(s)
- Barış Genç
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA
| | - Boram Nho
- School of Biological Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Hana Seung
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Benjamin Helmold
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA
| | - Huiwon Park
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Öge Gözütok
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA
| | - Seunghyun Kim
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Jinil Park
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Sanghyun Ye
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Haneul Lee
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Nayeon Lee
- School of Biological Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seung-Shin Yu
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Sunyoung Kim
- School of Biological Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Junghun Lee
- School of Biological Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
- Helixmith Co., Ltd., R&D Center, 21, Magokjungang 8-ro 7-gil, Gangseo-gu, Seoul, 07794, Republic of Korea.
| | - Hande Özdinler
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA.
- Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Center for Developmental Therapeutics, Northwestern University, Evanston, IL, 60208, USA.
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Gosset P, Camu W, Raoul C, Mezghrani A. Prionoids in amyotrophic lateral sclerosis. Brain Commun 2022; 4:fcac145. [PMID: 35783556 PMCID: PMC9242622 DOI: 10.1093/braincomms/fcac145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/16/2022] [Accepted: 06/01/2022] [Indexed: 12/20/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is the third most frequent neurodegenerative disease after Alzheimer’s and Parkinson’s disease. ALS is characterized by the selective and progressive loss of motoneurons in the spinal cord, brainstem and cerebral cortex. Clinical manifestations typically occur in midlife and start with focal muscle weakness, followed by the rapid and progressive wasting of muscles and subsequent paralysis. As with other neurodegenerative diseases, the condition typically begins at an initial point and then spreads along neuroanatomical tracts. This feature of disease progression suggests the spreading of prion-like proteins called prionoids in the affected tissues, which is similar to the spread of prion observed in Creutzfeldt-Jakob disease. Intensive research over the last decade has proposed the ALS-causing gene products Cu/Zn superoxide dismutase 1, TAR DNA-binding protein of 43 kDa, and fused in sarcoma as very plausible prionoids contributing to the spread of the pathology. In this review, we will discuss the molecular and cellular mechanisms leading to the propagation of these prionoids in ALS.
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Affiliation(s)
- Philippe Gosset
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
| | - William Camu
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
| | - Cedric Raoul
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
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Genç B, Jara JH, Sanchez SS, Lagrimas AKB, Gözütok Ö, Koçak N, Zhu Y, Hande Özdinler P. Upper motor neurons are a target for gene therapy and UCHL1 is necessary and sufficient to improve cellular integrity of diseased upper motor neurons. Gene Ther 2022; 29:178-192. [PMID: 34853443 PMCID: PMC9018479 DOI: 10.1038/s41434-021-00303-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/15/2022]
Abstract
There are no effective cures for upper motor neuron (UMN) diseases, such as amyotrophic lateral sclerosis (ALS), primary lateral sclerosis, and hereditary spastic paraplegia. Here, we show UMN loss occurs independent of spinal motor neuron degeneration and that UMNs are indeed effective cellular targets for gene therapy, which offers a potential solution especially for UMN disease patients. UCHL1 (ubiquitin C-terminal hydrolase-L1) is a deubiquitinating enzyme crucial for maintaining free ubiquitin levels. Corticospinal motor neurons (CSMN, a.k.a UMNs in mice) show early, selective, and profound degeneration in Uchl1nm3419 (UCHL1-/-) mice, which lack all UCHL1 function. When UCHL1 activity is ablated only from spinal motor neurons, CSMN remained intact. However, restoring UCHL1 specifically in CSMN of UCHL1-/- mice via directed gene delivery was sufficient to improve CSMN integrity to the healthy control levels. In addition, when UCHL1 gene was delivered selectively to CSMN that are diseased due to misfolded SOD1 toxicity and TDP-43 pathology via AAV-mediated retrograde transduction, the disease causing misfolded SOD1 and mutant human TDP-43 were reduced in hSOD1G93A and prpTDP-43A315T models, respectively. Diseased CSMN retained their neuronal integrity and cytoarchitectural stability in two different mouse models that represent two distinct causes of neurodegeneration in ALS.
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Affiliation(s)
- Barış Genç
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Javier H Jara
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Santana S Sanchez
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Amiko K B Lagrimas
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Öge Gözütok
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Nuran Koçak
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Yongling Zhu
- Departments of Ophthalmology and Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - P Hande Özdinler
- Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA.
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Advances in Gene Delivery Methods to Label and Modulate Activity of Upper Motor Neurons: Implications for Amyotrophic Lateral Sclerosis. Brain Sci 2021; 11:brainsci11091112. [PMID: 34573134 PMCID: PMC8471472 DOI: 10.3390/brainsci11091112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 11/17/2022] Open
Abstract
The selective degeneration of both upper motor neurons (UMNs) and lower motor neurons (LMNs) is the pathological hallmark of amyotrophic lateral sclerosis (ALS). Unlike the simple organisation of LMNs in the brainstem and spinal cord, UMNs are embedded in the complex cytoarchitecture of the primary motor cortex, which complicates their identification. UMNs therefore remain a challenging neuronal population to study in ALS research, particularly in the early pre-symptomatic stages of animal models. A better understanding of the mechanisms that lead to selective UMN degeneration requires unequivocal visualization and cellular identification of vulnerable UMNs within the heterogeneous cortical neuronal population and circuitry. Here, we review recent novel gene delivery methods developed to cellularly identify vulnerable UMNs and modulate their activity in various mouse models. A critical overview of retrograde tracers, viral vectors encoding reporter genes and transgenic reporter mice used to visualize UMNs in mouse models of ALS is provided. Functional targeting of UMNs in vivo with the advent of optogenetic and chemogenetic technology is also discussed. These exciting gene delivery techniques will facilitate improved anatomical mapping, cell-specific gene expression profiling and targeted manipulation of UMN activity in mice. These advancements in the field pave the way for future work to uncover the precise role of UMNs in ALS and improve future therapeutic targeting of UMNs.
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Marques C, Burg T, Scekic-Zahirovic J, Fischer M, Rouaux C. Upper and Lower Motor Neuron Degenerations Are Somatotopically Related and Temporally Ordered in the Sod1 Mouse Model of Amyotrophic Lateral Sclerosis. Brain Sci 2021; 11:brainsci11030369. [PMID: 33805792 PMCID: PMC7998935 DOI: 10.3390/brainsci11030369] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/06/2021] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating and fatal neurodegenerative disease arising from the combined degeneration of upper motor neurons (UMN) in the motor cortex, and lower motor neurons (LMN) in the brainstem and spinal cord. This dual impairment raises two major questions: (i) are the degenerations of these two neuronal populations somatotopically related? and if yes (ii), where does neurodegeneration start? If studies carried out on ALS patients clearly demonstrated the somatotopic relationship between UMN and LMN degenerations, their temporal relationship remained an unanswered question. In the present study, we took advantage of the well-described Sod1G86R model of ALS to interrogate the somatotopic and temporal relationships between UMN and LMN degenerations in ALS. Using retrograde labelling from the cervical or lumbar spinal cord of Sod1G86R mice and controls to identify UMN, along with electrophysiology and histology to assess LMN degeneration, we applied rigorous sampling, counting, and statistical analyses, and show that UMN and LMN degenerations are somatotopically related and that UMN depletion precedes LMN degeneration. Together, the data indicate that UMN degeneration is a particularly early and thus relevant event in ALS, in accordance with a possible cortical origin of the disease, and emphasize the need to further elucidate the molecular mechanisms behind UMN degeneration, towards new therapeutic avenues.
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Genç B, Gautam M, Gözütok Ö, Dervishi I, Sanchez S, Goshu GM, Koçak N, Xie E, Silverman RB, Özdinler PH. Improving mitochondria and ER stability helps eliminate upper motor neuron degeneration that occurs due to mSOD1 toxicity and TDP-43 pathology. Clin Transl Med 2021; 11:e336. [PMID: 33634973 PMCID: PMC7898037 DOI: 10.1002/ctm2.336] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Upper motor neurons (UMNs) are a key component of motor neuron circuitry. Their degeneration is a hallmark for diseases, such as hereditary spastic paraplegia (HSP), primary lateral sclerosis (PLS), and amyotrophic lateral sclerosis (ALS). Currently there are no preclinical assays investigating cellular responses of UMNs to compound treatment, even for diseases of the UMNs. The basis of UMN vulnerability is not fully understood, and no compound has yet been identified to improve the health of diseased UMNs: two major roadblocks for building effective treatment strategies. METHODS Novel UMN reporter models, in which UMNs that are diseased because of misfolded superoxide dismutase protein (mSOD1) toxicity and TDP-43 pathology are labeled with eGFP expression, allow direct assessment of UMN response to compound treatment. Electron microscopy reveals very precise aspects of endoplasmic reticulum (ER) and mitochondrial damage. Administration of NU-9, a compound initially identified based on its ability to reduce mSOD1 toxicity, has profound impact on improving the health and stability of UMNs, as identified by detailed cellular and ultrastructural analyses. RESULTS Problems with mitochondria and ER are conserved in diseased UMNs among different species. NU-9 has drug-like pharmacokinetic properties. It lacks toxicity and crosses the blood brain barrier. NU-9 improves the structural integrity of mitochondria and ER, reduces levels of mSOD1, stabilizes degenerating UMN apical dendrites, improves motor behavior measured by the hanging wire test, and eliminates ongoing degeneration of UMNs that become diseased both because of mSOD1 toxicity and TDP-43 pathology, two distinct and important overarching causes of motor neuron degeneration. CONCLUSIONS Mechanism-focused and cell-based drug discovery approaches not only addressed key cellular defects responsible for UMN loss, but also identified NU-9, the first compound to improve the health of diseased UMNs, neurons that degenerate in ALS, HSP, PLS, and ALS/FTLD patients.
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Affiliation(s)
- Barış Genç
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Mukesh Gautam
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Öge Gözütok
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Ina Dervishi
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Santana Sanchez
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Gashaw M. Goshu
- Department of ChemistryNorthwestern UniversityEvanstonIllinoisUSA
| | - Nuran Koçak
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Edward Xie
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Richard B. Silverman
- Department of ChemistryNorthwestern UniversityEvanstonIllinoisUSA
- Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Center for Developmental TherapeuticsNorthwestern UniversityEvanstonIllinoisUSA
- Department of Pharmacology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Chemistry of Life Processes InstituteNorthwestern UniversityEvanstonIL60208
| | - P. Hande Özdinler
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Center for Developmental TherapeuticsNorthwestern UniversityEvanstonIllinoisUSA
- Chemistry of Life Processes InstituteNorthwestern UniversityEvanstonIL60208
- Mesulam Center for Cognitive Neurology and Alzheimer's DiseaseNorthwestern University, Feinberg School of MedicineChicagoIL60611
- Les Turner ALS CenterNorthwestern University, Feinberg School of MedicineChicagoIL60611
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