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Kathiresan DS, Balasubramani R, Marudhachalam K, Jaiswal P, Ramesh N, Sureshbabu SG, Puthamohan VM, Vijayan M. Role of Mitochondrial Dysfunctions in Neurodegenerative Disorders: Advances in Mitochondrial Biology. Mol Neurobiol 2024:10.1007/s12035-024-04469-x. [PMID: 39269547 DOI: 10.1007/s12035-024-04469-x] [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: 04/04/2024] [Accepted: 08/30/2024] [Indexed: 09/15/2024]
Abstract
Mitochondria, essential organelles responsible for cellular energy production, emerge as a key factor in the pathogenesis of neurodegenerative disorders. This review explores advancements in mitochondrial biology studies that highlight the pivotal connection between mitochondrial dysfunctions and neurological conditions such as Alzheimer's, Parkinson's, Huntington's, ischemic stroke, and vascular dementia. Mitochondrial DNA mutations, impaired dynamics, and disruptions in the ETC contribute to compromised energy production and heightened oxidative stress. These factors, in turn, lead to neuronal damage and cell death. Recent research has unveiled potential therapeutic strategies targeting mitochondrial dysfunction, including mitochondria targeted therapies and antioxidants. Furthermore, the identification of reliable biomarkers for assessing mitochondrial dysfunction opens new avenues for early diagnosis and monitoring of disease progression. By delving into these advancements, this review underscores the significance of understanding mitochondrial biology in unraveling the mechanisms underlying neurodegenerative disorders. It lays the groundwork for developing targeted treatments to combat these devastating neurological conditions.
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Affiliation(s)
- Divya Sri Kathiresan
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Rubadevi Balasubramani
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Kamalesh Marudhachalam
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Piyush Jaiswal
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Nivedha Ramesh
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Suruthi Gunna Sureshbabu
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India
| | - Vinayaga Moorthi Puthamohan
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Nadu, Tamil, 641046, India.
| | - Murali Vijayan
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA.
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Hana TA, Mousa VG, Lin A, Haj-Hussein RN, Michael AH, Aziz MN, Kamaridinova SU, Basnet S, Ormerod KG. Developmental and physiological impacts of pathogenic human huntingtin protein in the nervous system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.30.610525. [PMID: 39257834 PMCID: PMC11383668 DOI: 10.1101/2024.08.30.610525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Huntington's Disease (HD) is a neurodegenerative disorder, part of the nine identified inherited polyglutamine (polyQ) diseases. Most commonly, HD pathophysiology manifests in middle-aged adults with symptoms including progressive loss of motor control, cognitive decline, and psychiatric disturbances. Associated with the pathophysiology of HD is the formation of insoluble fragments of the huntingtin protein (htt) that tend to aggregate in the nucleus and cytoplasm of neurons. To track both the intracellular progression of the aggregation phenotype as well as the physiological deficits associated with mutant htt, two constructs of human HTT were expressed with varying polyQ lengths, non-pathogenic-htt (Q15, NP-htt) and pathogenic-htt (Q138, P-htt), with an N-terminal RFP tag for in vivo visualization. P-htt aggregates accumulate in the ventral nerve cord cell bodies as early as 24 hours post hatching and significant aggregates form in the segmental nerve branches at 48 hours post hatching. Organelle trafficking up-and downstream of aggregates formed in motor neurons showed severe deficits in trafficking dynamics. To explore putative downstream deficits of htt aggregation, ultrastructural changes of presynaptic motor neurons and muscles were assessed, but no significant effects were observed. However, the force and kinetics of muscle contractions were severely affected in P-htt animals, reminiscent of human chorea. Reduced muscle force production translated to altered locomotory behavior. A novel HD aggregation model was established to track htt aggregation throughout adulthood in the wing, showing similar aggregation patterns with larvae. Expressing P-htt in the adult nervous system resulted in significantly reduced lifespan, which could be partially rescued by feeding flies the mTOR inhibitor rapamycin. These findings advance our understanding of htt aggregate progression as well the downstream physiological impacts on the nervous system and peripheral tissues.
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Tenchov R, Sasso JM, Zhou QA. Polyglutamine (PolyQ) Diseases: Navigating the Landscape of Neurodegeneration. ACS Chem Neurosci 2024; 15:2665-2694. [PMID: 38996083 PMCID: PMC11311141 DOI: 10.1021/acschemneuro.4c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/02/2024] [Accepted: 06/26/2024] [Indexed: 07/14/2024] Open
Abstract
Polyglutamine (polyQ) diseases are a group of inherited neurodegenerative disorders caused by expanded cytosine-adenine-guanine (CAG) repeats encoding proteins with abnormally expanded polyglutamine tract. A total of nine polyQ disorders have been identified, including Huntington's disease, six spinocerebellar ataxias, dentatorubral pallidoluysian atrophy (DRPLA), and spinal and bulbar muscular atrophy (SBMA). The diseases of this class are each considered rare, yet polyQ diseases constitute the largest group of monogenic neurodegenerative disorders. While each subtype of polyQ diseases has its own causative gene, certain pathologic molecular attributes have been implicated in virtually all of the polyQ diseases, including protein aggregation, proteolytic cleavage, neuronal dysfunction, transcription dysregulation, autophagy impairment, and mitochondrial dysfunction. Although animal models of polyQ disease are available helping to understand their pathogenesis and access disease-modifying therapies, there is neither a cure nor prevention for these diseases, with only symptomatic treatments available. In this paper, we analyze data from the CAS Content Collection to summarize the research progress in the class of polyQ diseases. We examine the publication landscape in the area in effort to provide insights into current knowledge advances and developments. We review the most discussed concepts and assess the strategies to combat these diseases. Finally, we inspect clinical applications of products against polyQ diseases with their development pipelines. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding the class of polyQ diseases, to outline challenges, and evaluate growth opportunities to further efforts in combating the diseases.
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Affiliation(s)
- Rumiana Tenchov
- CAS, a division of the American
Chemical Society, Columbus, Ohio 43210, United States
| | - Janet M. Sasso
- CAS, a division of the American
Chemical Society, Columbus, Ohio 43210, United States
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Wodrich APK, Harris BT, Giniger E. Changes in mitochondrial distribution occur at the axon initial segment in association with neurodegeneration in Drosophila. Biol Open 2024; 13:bio060335. [PMID: 38912559 PMCID: PMC11261633 DOI: 10.1242/bio.060335] [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: 01/26/2024] [Accepted: 06/17/2024] [Indexed: 06/25/2024] Open
Abstract
Changes in mitochondrial distribution are a feature of numerous age-related neurodegenerative diseases. In Drosophila, reducing the activity of Cdk5 causes a neurodegenerative phenotype and is known to affect several mitochondrial properties. Therefore, we investigated whether alterations of mitochondrial distribution are involved in Cdk5-associated neurodegeneration. We find that reducing Cdk5 activity does not alter the balance of mitochondrial localization to the somatodendritic versus axonal neuronal compartments of the mushroom body, the learning and memory center of the Drosophila brain. We do, however, observe changes in mitochondrial distribution at the axon initial segment (AIS), a neuronal compartment located in the proximal axon involved in neuronal polarization and action potential initiation. Specifically, we observe that mitochondria are partially excluded from the AIS in wild-type neurons, but that this exclusion is lost upon reduction of Cdk5 activity, concomitant with the shrinkage of the AIS domain that is known to occur in this condition. This mitochondrial redistribution into the AIS is not likely due to the shortening of the AIS domain itself but rather due to altered Cdk5 activity. Furthermore, mitochondrial redistribution into the AIS is unlikely to be an early driver of neurodegeneration in the context of reduced Cdk5 activity.
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Affiliation(s)
- Andrew P. K. Wodrich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC 20007, USA
- College of Medicine, University of Kentucky, Lexington, KY 40506, USA
| | - Brent T. Harris
- Department of Pathology, Georgetown University, Washington, DC 20007, USA
- Department of Neurology, Georgetown University, Washington, DC 20007, USA
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Liu D, Webber HC, Bian F, Xu Y, Prakash M, Feng X, Yang M, Yang H, You IJ, Li L, Liu L, Liu P, Huang H, Chang CY, Liu L, Shah SH, Torre AL, Welsbie DS, Sun Y, Duan X, Goldberg JL, Braun M, Lansky Z, Hu Y. Optineurin-facilitated axonal mitochondria delivery promotes neuroprotection and axon regeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.02.587832. [PMID: 38617277 PMCID: PMC11014509 DOI: 10.1101/2024.04.02.587832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Optineurin (OPTN) mutations are linked to amyotrophic lateral sclerosis (ALS) and normal tension glaucoma (NTG), but a relevant animal model is lacking, and the molecular mechanisms underlying neurodegeneration are unknown. We found that OPTN C-terminus truncation (OPTN∆C) causes late-onset neurodegeneration of retinal ganglion cells (RGCs), optic nerve (ON), and spinal cord motor neurons, preceded by a striking decrease of axonal mitochondria. Surprisingly, we discover that OPTN directly interacts with both microtubules and the mitochondrial transport complex TRAK1/KIF5B, stabilizing them for proper anterograde axonal mitochondrial transport, in a C-terminus dependent manner. Encouragingly, overexpressing OPTN/TRAK1/KIF5B reverses not only OPTN truncation-induced, but also ocular hypertension-induced neurodegeneration, and promotes striking ON regeneration. Therefore, in addition to generating new animal models for NTG and ALS, our results establish OPTN as a novel facilitator of the microtubule-dependent mitochondrial transport necessary for adequate axonal mitochondria delivery, and its loss as the likely molecular mechanism of neurodegeneration.
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Affiliation(s)
- Dong Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Hannah C. Webber
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Fuyun Bian
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yangfan Xu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Manjari Prakash
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Xue Feng
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Ming Yang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Hang Yang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - In-Jee You
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liping Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pingting Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Chien-Yi Chang
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Liang Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Sahil H Shah
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Anna La Torre
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA; USA
| | - Derek S. Welsbie
- Viterbi Family Department of Ophthalmology, University of California San Diego, San Diego, CA; USA
| | - Yang Sun
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xin Duan
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA; USA
| | - Jeffrey Louis Goldberg
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Marcus Braun
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Zdenek Lansky
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Yang Hu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
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Jurcau A, Simion A, Jurcau MC. Emerging antibody-based therapies for Huntington's disease: current status and perspectives for future development. Expert Rev Neurother 2024; 24:299-312. [PMID: 38324338 DOI: 10.1080/14737175.2024.2314183] [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: 11/19/2023] [Accepted: 01/31/2024] [Indexed: 02/08/2024]
Abstract
INTRODUCTION Being an inherited neurodegenerative disease with an identifiable genetic defect, Huntington's disease (HD) is a suitable candidate for early intervention, possibly even in the pre-symptomatic stage. Our recent advances in elucidating the pathogenesis of HD have revealed a series of novel potential therapeutic targets, among which immunotherapies are actively pursued in preclinical experiments. AREAS COVERED This review focuses on the potential of antibody-based treatments targeting various epitopes (of mutant huntingtin as well as phosphorylated tau) that are currently evaluated in vitro and in animal experiments. The references used in this review were retrieved from the PubMed database, searching for immunotherapies in HD, and clinical trial registries were reviewed for molecules already evaluated in clinical trials. EXPERT OPINION Antibody-based therapies have raised considerable interest in a series of neurodegenerative diseases characterized by deposition of aggregated of aberrantly folded proteins, HD included. Intrabodies and nanobodies can interact with mutant huntingtin inside the nervous cells. However, the conflicting results obtained with some of these intrabodies highlight the need for proper choice of epitopes and for developing animal models more closely mimicking human disease. Approval of these strategies will require a considerable financial and logistic effort on behalf of healthcare systems.
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Affiliation(s)
- Anamaria Jurcau
- Department of Psycho-Neurosciences and Rehabilitation, University of Oradea, Oradea, Romania
| | - Aurel Simion
- Department of Psycho-Neurosciences and Rehabilitation, University of Oradea, Oradea, Romania
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Wodrich APK, Harris BT, Giniger E. Changes in mitochondrial distribution occur at the axon initial segment in association with neurodegeneration in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580288. [PMID: 38405730 PMCID: PMC10888798 DOI: 10.1101/2024.02.14.580288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Changes in mitochondrial distribution are a feature of numerous age-related neurodegenerative diseases. In Drosophila, reducing the activity of Cdk5 causes a neurodegenerative phenotype and is known to affect several mitochondrial properties. Therefore, we investigated whether alterations of mitochondrial distribution are involved in Cdk5-associated neurodegeneration. We find that reducing Cdk5 activity does not alter the balance of mitochondrial localization to the somatodendritic vs. axonal neuronal compartments of the mushroom body, the learning and memory center of the Drosophila brain. We do, however, observe changes in mitochondrial distribution at the axon initial segment (AIS), a neuronal compartment located in the proximal axon involved in neuronal polarization and action potential initiation. Specifically, we observe that mitochondria are partially excluded from the AIS in wild-type neurons, but that this exclusion is lost upon reduction of Cdk5 activity, concomitant with the shrinkage of the AIS domain that is known to occur in this condition. This mitochondrial redistribution into the AIS is not likely due to the shortening of the AIS domain itself but rather due to altered Cdk5 activity. Furthermore, mitochondrial redistribution into the AIS is unlikely to be an early driver of neurodegeneration in the context of reduced Cdk5 activity.
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Affiliation(s)
- Andrew P. K. Wodrich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC
- College of Medicine, University of Kentucky, Lexington, KY
| | - Brent T. Harris
- Department of Pathology, Georgetown University, Washington, DC
- Department of Neurology, Georgetown University, Washington, DC
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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Wu C, Yin H, Fu S, Yoo H, Zhang M, Park H. Altered anterograde axonal transport of mitochondria in cultured striatal neurons of a knock-in mouse model of Huntington's disease. Biochem Biophys Res Commun 2024; 691:149246. [PMID: 38029540 DOI: 10.1016/j.bbrc.2023.149246] [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: 11/02/2023] [Revised: 11/12/2023] [Accepted: 11/12/2023] [Indexed: 12/01/2023]
Abstract
Huntington's disease (HD) is a progressive genetic neurodegenerative disease caused by an abnormal expansion of a cytosine-adenine-guanine trinucleotide repeat in the huntingtin gene. One pathological feature of HD is neuronal loss in the striatum. Despite many efforts, mechanisms underlying neuronal loss in HD striatum remain elusive. It was suggested that the mutant huntingtin protein interacts mitochondrial proteins and causes mitochondrial dysfunction in striatal neurons. However, whether axonal transport of mitochondria is altered in HD striatal neurons remains controversial. Here, we examined axonal transport of single mitochondria labelled with Mito-DsRed2 in cultured striatal neurons of zQ175 knock-in mice (a knock-in mouse model of HD). We observed decreased anterograde axonal transport of proximal mitochondria in HD striatal neurons compared with wild-type (WT) striatal neurons. Decreased anterograde transport in HD striatal neurons was prevented by overexpressing mitochondrial Rho GTPase 1 (Miro1). Our results offer a new insight into mechanisms underlying neuronal loss in the striatum in HD.
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Affiliation(s)
- Chao Wu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Haoran Yin
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Songdi Fu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hanna Yoo
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Min Zhang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hyokeun Park
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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Stonebraker AR, Hankin R, Kapp KL, Li P, Valentine SJ, Legleiter J. Charge within Nt17 peptides modulates huntingtin aggregation and initial lipid binding events. Biophys Chem 2023; 303:107123. [PMID: 37852163 PMCID: PMC10843285 DOI: 10.1016/j.bpc.2023.107123] [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: 06/27/2023] [Revised: 09/22/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
Toxic aggregation of pathogenic huntingtin protein (htt) is implicated in Huntington's disease and influenced by various factors, including the first seventeen amino acids at the N-terminus (Nt17) and the presence of lipid membranes. Nt17 has a propensity to form an amphipathic α-helix in the presence of binding partners, which promotes α-helix rich oligomer formation and facilitates htt/lipid interactions. Within Nt17 are multiple sites that are subject to post-translational modification, including acetylation and phosphorylation. Acetylation can occur at lysine 6, 9, and/or 15 while phosphorylation can occur at threonine 3, serine 13, and/or serine 16. Such modifications impact aggregation and lipid binding through the alteration of various intra- and intermolecular interactions. When incubated with htt-exon1(46Q), free Nt17 peptides containing point mutations mimicking acetylation or phosphorylation reduced fibril formation and altered oligomer morphologies. Upon exposure to lipid vesicles, changes to peptide/lipid complexation were observed and peptide-containing oligomers demonstrated reduced lipid interactions.
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Affiliation(s)
- Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Rachel Hankin
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Kathryn L Kapp
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Peng Li
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA.
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Reed AL, Mitchell W, Alexandrescu AT, Alder NN. Interactions of amyloidogenic proteins with mitochondrial protein import machinery in aging-related neurodegenerative diseases. Front Physiol 2023; 14:1263420. [PMID: 38028797 PMCID: PMC10652799 DOI: 10.3389/fphys.2023.1263420] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023] Open
Abstract
Most mitochondrial proteins are targeted to the organelle by N-terminal mitochondrial targeting sequences (MTSs, or "presequences") that are recognized by the import machinery and subsequently cleaved to yield the mature protein. MTSs do not have conserved amino acid compositions, but share common physicochemical properties, including the ability to form amphipathic α-helical structures enriched with basic and hydrophobic residues on alternating faces. The lack of strict sequence conservation implies that some polypeptides can be mistargeted to mitochondria, especially under cellular stress. The pathogenic accumulation of proteins within mitochondria is implicated in many aging-related neurodegenerative diseases, including Alzheimer's, Parkinson's, and Huntington's diseases. Mechanistically, these diseases may originate in part from mitochondrial interactions with amyloid-β precursor protein (APP) or its cleavage product amyloid-β (Aβ), α-synuclein (α-syn), and mutant forms of huntingtin (mHtt), respectively, that are mediated in part through their associations with the mitochondrial protein import machinery. Emerging evidence suggests that these amyloidogenic proteins may present cryptic targeting signals that act as MTS mimetics and can be recognized by mitochondrial import receptors and transported into different mitochondrial compartments. Accumulation of these mistargeted proteins could overwhelm the import machinery and its associated quality control mechanisms, thereby contributing to neurological disease progression. Alternatively, the uptake of amyloidogenic proteins into mitochondria may be part of a protein quality control mechanism for clearance of cytotoxic proteins. Here we review the pathomechanisms of these diseases as they relate to mitochondrial protein import and effects on mitochondrial function, what features of APP/Aβ, α-syn and mHtt make them suitable substrates for the import machinery, and how this information can be leveraged for the development of therapeutic interventions.
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Affiliation(s)
- Ashley L. Reed
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Wayne Mitchell
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Andrei T. Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Nathan N. Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
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Jiang A, Handley RR, Lehnert K, Snell RG. From Pathogenesis to Therapeutics: A Review of 150 Years of Huntington's Disease Research. Int J Mol Sci 2023; 24:13021. [PMID: 37629202 PMCID: PMC10455900 DOI: 10.3390/ijms241613021] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a debilitating neurodegenerative genetic disorder caused by an expanded polyglutamine-coding (CAG) trinucleotide repeat in the huntingtin (HTT) gene. HD behaves as a highly penetrant dominant disorder likely acting through a toxic gain of function by the mutant huntingtin protein. Widespread cellular degeneration of the medium spiny neurons of the caudate nucleus and putamen are responsible for the onset of symptomology that encompasses motor, cognitive, and behavioural abnormalities. Over the past 150 years of HD research since George Huntington published his description, a plethora of pathogenic mechanisms have been proposed with key themes including excitotoxicity, dopaminergic imbalance, mitochondrial dysfunction, metabolic defects, disruption of proteostasis, transcriptional dysregulation, and neuroinflammation. Despite the identification and characterisation of the causative gene and mutation and significant advances in our understanding of the cellular pathology in recent years, a disease-modifying intervention has not yet been clinically approved. This review includes an overview of Huntington's disease, from its genetic aetiology to clinical presentation and its pathogenic manifestation. An updated view of molecular mechanisms and the latest therapeutic developments will also be discussed.
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Affiliation(s)
- Andrew Jiang
- Applied Translational Genetics Group, Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand; (R.R.H.); (K.L.); (R.G.S.)
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Duarte FV, Ciampi D, Duarte CB. Mitochondria as central hubs in synaptic modulation. Cell Mol Life Sci 2023; 80:173. [PMID: 37266732 DOI: 10.1007/s00018-023-04814-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/03/2023]
Abstract
Mitochondria are present in the pre- and post-synaptic regions, providing the energy required for the activity of these very specialized neuronal compartments. Biogenesis of synaptic mitochondria takes place in the cell body, and these organelles are then transported to the synapse by motor proteins that carry their cargo along microtubule tracks. The transport of mitochondria along neurites is a highly regulated process, being modulated by the pattern of neuronal activity and by extracellular cues that interact with surface receptors. These signals act by controlling the distribution of mitochondria and by regulating their activity. Therefore, mitochondria activity at the synapse allows the integration of different signals and the organelles are important players in the response to synaptic stimulation. Herein we review the available evidence regarding the regulation of mitochondrial dynamics by neuronal activity and by neuromodulators, and how these changes in the activity of mitochondria affect synaptic communication.
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Affiliation(s)
- Filipe V Duarte
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- III - Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Daniele Ciampi
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Carlos B Duarte
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
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Yang X, Ma Z, Lian P, Xu Y, Cao X. Common mechanisms underlying axonal transport deficits in neurodegenerative diseases: a mini review. Front Mol Neurosci 2023; 16:1172197. [PMID: 37168679 PMCID: PMC10164940 DOI: 10.3389/fnmol.2023.1172197] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/05/2023] [Indexed: 05/13/2023] Open
Abstract
Many neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the accumulation of pathogenic proteins and abnormal localization of organelles. These pathological features may be related to axonal transport deficits in neurons, which lead to failures in pathological protein targeting to specific sites for degradation and organelle transportation to designated areas needed for normal physiological functioning. Axonal transport deficits are most likely early pathological events in such diseases and gradually lead to the loss of axonal integrity and other degenerative changes. In this review, we investigated reports of mechanisms underlying the development of axonal transport deficits in a variety of common neurodegenerative diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease and Huntington's disease to provide new ideas for therapeutic targets that may be used early in the disease process. The mechanisms can be summarized as follows: (1) motor protein changes including expression levels and post-translational modification alteration; (2) changes in microtubules including reducing stability and disrupting tracks; (3) changes in cargoes including diminished binding to motor proteins. Future studies should determine which axonal transport defects are disease-specific and whether they are suitable therapeutic targets in neurodegenerative diseases.
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Ahamad S, Bhat SA. The Emerging Landscape of Small-Molecule Therapeutics for the Treatment of Huntington's Disease. J Med Chem 2022; 65:15993-16032. [PMID: 36490325 DOI: 10.1021/acs.jmedchem.2c00799] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene (HTT). The new insights into HD's cellular and molecular pathways have led to the identification of numerous potent small-molecule therapeutics for HD therapy. The field of HD-targeting small-molecule therapeutics is accelerating, and the approval of these therapeutics to combat HD may be expected in the near future. For instance, preclinical candidates such as naphthyridine-azaquinolone, AN1, AN2, CHDI-00484077, PRE084, EVP4593, and LOC14 have shown promise for further optimization to enter into HD clinical trials. This perspective aims to summarize the advent of small-molecule therapeutics at various stages of clinical development for HD therapy, emphasizing their structure and design, therapeutic effects, and specific mechanisms of action. Further, we have highlighted the key drivers involved in HD pathogenesis to provide insights into the basic principle for designing promising anti-HD therapeutic leads.
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Affiliation(s)
- Shakir Ahamad
- Department of Chemistry, Aligarh Muslim University, Aligarh, Uttar Pradesh202002, India
| | - Shahnawaz A Bhat
- Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh202002, India
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15
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Olesen MA, Villavicencio-Tejo F, Quintanilla RA. The use of fibroblasts as a valuable strategy for studying mitochondrial impairment in neurological disorders. Transl Neurodegener 2022; 11:36. [PMID: 35787292 PMCID: PMC9251940 DOI: 10.1186/s40035-022-00308-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 05/26/2022] [Indexed: 11/10/2022] Open
Abstract
Neurological disorders (NDs) are characterized by progressive neuronal dysfunction leading to synaptic failure, cognitive impairment, and motor injury. Among these diseases, Alzheimer's disease (AD), Parkinson's disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS) have raised a significant research interest. These disorders present common neuropathological signs, including neuronal dysfunction, protein accumulation, oxidative damage, and mitochondrial abnormalities. In this context, mitochondrial impairment is characterized by a deficiency in ATP production, excessive production of reactive oxygen species, calcium dysregulation, mitochondrial transport failure, and mitochondrial dynamics deficiencies. These defects in mitochondrial health could compromise the synaptic process, leading to early cognitive dysfunction observed in these NDs. Interestingly, skin fibroblasts from AD, PD, HD, and ALS patients have been suggested as a useful strategy to investigate and detect early mitochondrial abnormalities in these NDs. In this context, fibroblasts are considered a viable model for studying neurodegenerative changes due to their metabolic and biochemical relationships with neurons. Also, studies of our group and others have shown impairment of mitochondrial bioenergetics in fibroblasts from patients diagnosed with sporadic and genetic forms of AD, PD, HD, and ALS. Interestingly, these mitochondrial abnormalities have been observed in the brain tissues of patients suffering from the same pathologies. Therefore, fibroblasts represent a novel strategy to study the genesis and progression of mitochondrial dysfunction in AD, PD, HD, and ALS. This review discusses recent evidence that proposes fibroblasts as a potential target to study mitochondrial bioenergetics impairment in neurological disorders and consequently to search for new biomarkers of neurodegeneration.
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Affiliation(s)
- Margrethe A Olesen
- Laboratory of Neurodegenerative Diseases, Facultad de Ciencias de La Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Francisca Villavicencio-Tejo
- Laboratory of Neurodegenerative Diseases, Facultad de Ciencias de La Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Rodrigo A Quintanilla
- Laboratory of Neurodegenerative Diseases, Facultad de Ciencias de La Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.
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16
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Adegbuyiro A, Stonebraker AR, Sedighi F, Fan CK, Hodges B, Li P, Valentine SJ, Legleiter J. Oxidation Promotes Distinct Huntingtin Aggregates in the Presence and Absence of Membranes. Biochemistry 2022; 61:1517-1530. [PMID: 35759798 DOI: 10.1021/acs.biochem.2c00212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expansion of a polyglutamine (polyQ) domain within the first exon of the huntingtin (htt) protein is the underlying cause of Huntington's disease, a genetic neurodegenerative disorder. PolyQ expansion triggers htt aggregation into oligomers, fibrils, and inclusions. The 17 N-terminal amino acids (Nt17) of htt-exon1, which directly precede the polyQ domain enhances polyQ fibrillization and functions as a lipid-binding domain. A variety of post-translational modifications occur within Nt17, including oxidation of two methionine residues. Here, the impact of oxidation within Nt17 on htt aggregation both in the presence and absence of lipid membranes was investigated. Treatment with hydrogen peroxide (H2O2) reduced fibril formation in a dose-dependent manner, resulting in shorter fibrils and an increased oligomer population. With excessive H2O2 treatments, fibrils developed a unique morphological feature around their periphery. In the presence of total brain lipid vesicles, H2O2 impacted fibrillization in a similar manner. That is, oligomerization was promoted at the expense of fibril elongation. The interaction of unoxidized and oxidized htt with supported lipid bilayers was directly observed using in situ atomic force microscopy. Without oxidation, granular htt aggregates developed on the bilayer surface. However, in the presence of H2O2, distinct plateau-like regions initially developed on the bilayer surface that gave way to rougher patches containing granular aggregates. Collectively, these observations suggest that oxidation of methionine residues within Nt17 plays a crucial role in both the aggregation of htt and its ability to interact with lipid surfaces.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Breanna Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Peng Li
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States.,Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States
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17
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Naranjo-Galindo FJ, Ai R, Fang EF, Nilsen HL, SenGupta T. C. elegans as an Animal Model to Study the Intersection of DNA Repair, Aging and Neurodegeneration. FRONTIERS IN AGING 2022; 3:916118. [PMID: 35821838 PMCID: PMC9261396 DOI: 10.3389/fragi.2022.916118] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022]
Abstract
Since its introduction as a genetic model organism, Caenorhabditis elegans has yielded insights into the causes of aging. In addition, it has provided a molecular understanding of mechanisms of neurodegeneration, one of the devastating effects of aging. However, C. elegans has been less popular as an animal model to investigate DNA repair and genomic instability, which is a major hallmark of aging and also a cause of many rare neurological disorders. This article provides an overview of DNA repair pathways in C. elegans and the impact of DNA repair on aging hallmarks, such as mitochondrial dysfunction, telomere maintenance, and autophagy. In addition, we discuss how the combination of biological characteristics, new technical tools, and the potential of following precise phenotypic assays through a natural life-course make C. elegans an ideal model organism to study how DNA repair impact neurodegeneration in models of common age-related neurodegenerative diseases.
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Affiliation(s)
- Francisco José Naranjo-Galindo
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
- Section of Clinical Molecular Biology (EpiGen), Akershus University Hospital, Lørenskog, Norway
| | - Ruixue Ai
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
| | - Evandro Fei Fang
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
| | - Hilde Loge Nilsen
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
- Section of Clinical Molecular Biology (EpiGen), Akershus University Hospital, Lørenskog, Norway
- Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | - Tanima SenGupta
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
- Section of Clinical Molecular Biology (EpiGen), Akershus University Hospital, Lørenskog, Norway
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18
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Molecular Pathophysiological Mechanisms in Huntington's Disease. Biomedicines 2022; 10:biomedicines10061432. [PMID: 35740453 PMCID: PMC9219859 DOI: 10.3390/biomedicines10061432] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/11/2022] Open
Abstract
Huntington’s disease is an inherited neurodegenerative disease described 150 years ago by George Huntington. The genetic defect was identified in 1993 to be an expanded CAG repeat on exon 1 of the huntingtin gene located on chromosome 4. In the following almost 30 years, a considerable amount of research, using mainly animal models or in vitro experiments, has tried to unravel the complex molecular cascades through which the transcription of the mutant protein leads to neuronal loss, especially in the medium spiny neurons of the striatum, and identified excitotoxicity, transcriptional dysregulation, mitochondrial dysfunction, oxidative stress, impaired proteostasis, altered axonal trafficking and reduced availability of trophic factors to be crucial contributors. This review discusses the pathogenic cascades described in the literature through which mutant huntingtin leads to neuronal demise. However, due to the ubiquitous presence of huntingtin, astrocytes are also dysfunctional, and neuroinflammation may additionally contribute to Huntington’s disease pathology. The quest for therapies to delay the onset and reduce the rate of Huntington’s disease progression is ongoing, but is based on findings from basic research.
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Burtscher J, Romani M, Bernardo G, Popa T, Ziviani E, Hummel FC, Sorrentino V, Millet GP. Boosting mitochondrial health to counteract neurodegeneration. Prog Neurobiol 2022; 215:102289. [DOI: 10.1016/j.pneurobio.2022.102289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/23/2022] [Accepted: 05/25/2022] [Indexed: 12/22/2022]
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Kong G, Lê Cao KA, Hannan AJ. Alterations in the Gut Fungal Community in a Mouse Model of Huntington's Disease. Microbiol Spectr 2022; 10:e0219221. [PMID: 35262396 PMCID: PMC9045163 DOI: 10.1128/spectrum.02192-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/14/2022] [Indexed: 12/26/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a trinucleotide expansion in the HTT gene, which is expressed throughout the brain and body, including the gut epithelium and enteric nervous system. Afflicted individuals suffer from progressive impairments in motor, psychiatric, and cognitive faculties, as well as peripheral deficits, including the alteration of the gut microbiome. However, studies characterizing the gut microbiome in HD have focused entirely on the bacterial component, while the fungal community (mycobiome) has been overlooked. The gut mycobiome has gained recognition for its role in host homeostasis and maintenance of the gut epithelial barrier. We aimed to characterize the gut mycobiome profile in HD using fecal samples collected from the R6/1 transgenic mouse model (and wild-type littermate controls) from 4 to 12 weeks of age, corresponding to presymptomatic through to early disease stages. Shotgun sequencing was performed on fecal DNA samples, followed by metagenomic analyses. The HD gut mycobiome beta diversity was significantly different from that of wild-type littermates at 12 weeks of age, while no genotype differences were observed at the earlier time points. Similarly, greater alpha diversity was observed in the HD mice by 12 weeks of age. Key taxa, including Malassezia restricta, Yarrowia lipolytica, and Aspergillus species, were identified as having a negative association with HD. Furthermore, integration of the bacterial and fungal data sets at 12 weeks of age identified negative correlations between the HD-associated fungal species and Lactobacillus reuteri. These findings provide new insights into gut microbiome alterations in HD and may help identify novel therapeutic targets. IMPORTANCE Huntington's disease (HD) is a fatal neurodegenerative disorder affecting both the mind and body. We have recently discovered that gut bacteria are disrupted in HD. The present study provides the first evidence of an altered gut fungal community (mycobiome) in HD. The genomes of many thousands of gut microbes were sequenced and used to assess "metagenomics" in particular the different types of fungal species in the HD versus control gut, in a mouse model. At an early disease stage, before the onset of symptoms, the overall gut mycobiome structure (array of fungi) in HD mice was distinct from that of their wild-type littermates. Alterations of multiple key fungi species were identified as being associated with the onset of disease symptoms, some of which showed strong correlations with the gut bacterial community. This study highlights the potential role of gut fungi in HD and may facilitate the development of novel therapeutic approaches.
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Affiliation(s)
- Geraldine Kong
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne Brain Centre, Parkville, Australia
| | - Kim-Anh Lê Cao
- Melbourne Integrative Genomics, School of Mathematics and Statistics, University of Melbourne, Parkville, Australia
| | - Anthony J. Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne Brain Centre, Parkville, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Australia
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21
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Pradhan S, Gao R, Bush K, Zhang N, Wairkar YP, Sarkar PS. Polyglutamine Expansion in Huntingtin and Mechanism of DNA Damage Repair Defects in Huntington’s Disease. Front Cell Neurosci 2022; 16:837576. [PMID: 35444517 PMCID: PMC9013776 DOI: 10.3389/fncel.2022.837576] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/07/2022] [Indexed: 12/27/2022] Open
Abstract
Emerging evidence suggests that DNA repair deficiency and genome instability may be the impending signs of many neurological diseases. Genome-wide association (GWAS) studies have established a strong correlation between genes that play a role in DNA damage repair and many neurodegenerative diseases, including Huntington’s disease (HD), and several other trinucleotides repeat expansion-related hereditary ataxias. Recently, many reports have documented a significant role played by the DNA repair processes in aging and in modifying many neurodegenerative diseases, early during their progression. Studies from our lab and others have now begun to understand the mechanisms that cause defective DNA repair in HD and surprisingly, many proteins that have a strong link to known neurodegenerative diseases seem to be important players in these cellular pathways. Mutations in huntingtin (HTT) gene that lead to polyglutamine repeat expansion at the N-terminal of HTT protein has been shown to disrupt transcription-coupled DNA repair process, a specialized DNA repair process associated with transcription. Due to the recent progress made in understanding the mechanisms of DNA repair in relation to HD, in this review, we will mainly focus on the mechanisms by which the wild-type huntingtin (HTT) protein helps in DNA repair during transcription, and the how polyglutamine expansions in HTT impedes this process in HD. Further studies that identify new players in DNA repair will help in our understanding of this process in neurons. Furthermore, it should help us understand how various DNA repair mechanism(s) coordinate to maintain the normal physiology of neurons, and provide insights for the development of novel drugs at prodromal stages of these neurodegenerative diseases.
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Affiliation(s)
- Subrata Pradhan
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States
| | - Rui Gao
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States
| | - Keegan Bush
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, United States
| | - Nan Zhang
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, United States
| | - Yogesh P. Wairkar
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, United States
| | - Partha S. Sarkar
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, United States
- *Correspondence: Partha S. Sarkar,
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22
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Royea J, Khacho M. Examining Mitochondrial Morphology in Mouse Brains. Methods Mol Biol 2022; 2515:17-28. [PMID: 35776343 DOI: 10.1007/978-1-0716-2409-8_2] [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] [Indexed: 06/15/2023]
Abstract
Mitochondria are dynamic organelles that rely on a balance of opposing fission and fusion events to sustain mitochondrial function and efficiently meet the energy demands of a cell. As high-energy demanding cells, neurons rely heavily on optimally functional mitochondria with balanced mitochondrial dynamics, to ensure a sufficient energy supply required to maintain cell survival, establish membrane excitability and partake in processes of neurotransmission and plasticity. As such, many neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease) and stress conditions (e.g., stroke) leading to neuronal dysfunction or death are often associated with impaired mitochondrial function and dynamics, characterized by excessive mitochondrial fragmentation. For this reason, the assessment of mitochondrial morphology in neurons and within the brain can provide valuable information. The dynamic nature of mitochondria is not only observed in shape changes, but also changes in mitochondrial network connectivity and in cristae architecture. In this chapter, we will describe how mitochondrial morphology can be examined in vitro using hippocampal neuronal cultures and in vivo using mouse brain sections by immunocytochemistry, immunohistochemistry, and electron microscopy techniques.
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Affiliation(s)
- Jessika Royea
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Institute of Systems Biology (OISB), Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Center for Neuromuscular Disease (CNMD), University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute (uOBMRI), Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Mireille Khacho
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
- Ottawa Institute of Systems Biology (OISB), Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
- Center for Neuromuscular Disease (CNMD), University of Ottawa, Ottawa, ON, Canada.
- University of Ottawa Brain and Mind Research Institute (uOBMRI), Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
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23
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Sawant N, Morton H, Kshirsagar S, Reddy AP, Reddy PH. Mitochondrial Abnormalities and Synaptic Damage in Huntington's Disease: a Focus on Defective Mitophagy and Mitochondria-Targeted Therapeutics. Mol Neurobiol 2021; 58:6350-6377. [PMID: 34519969 DOI: 10.1007/s12035-021-02556-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/05/2021] [Indexed: 12/12/2022]
Abstract
Huntington's disease (HD) is a fatal and pure genetic disease with a progressive loss of medium spiny neurons (MSN). HD is caused by expanded polyglutamine repeats in the exon 1 of HD gene. Clinically, HD is characterized by chorea, seizures, involuntary movements, dystonia, cognitive decline, intellectual impairment, and emotional disturbances. Several years of intense research revealed that multiple cellular changes, including defective axonal transport, protein-protein interactions, defective bioenergetics, calcium dyshomeostasis, NMDAR activation, synaptic damage, mitochondrial abnormalities, and selective loss of medium spiny neurons are implicated in HD. Recent research on mutant huntingtin (mHtt) and mitochondria has found that mHtt interacts with the mitochondrial division protein, dynamin-related protein 1 (DRP1), enhances GTPase DRP1 enzymatic activity, and causes excessive mitochondrial fragmentation and abnormal distribution, leading to defective axonal transport of mitochondria and selective synaptic degeneration. Recent research also revealed that failure to remove dead and/or dying mitochondria is an early event in the disease progression. Currently, efforts are being made to reduce abnormal protein interactions and enhance synaptic mitophagy as therapeutic strategies for HD. The purpose of this article is to discuss recent research in HD progression. This article also discusses recent developments of cell and mouse models, cellular changes, mitochondrial abnormalities, DNA damage, bioenergetics, oxidative stress, mitophagy, and therapeutics strategies in HD.
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Affiliation(s)
- Neha Sawant
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Hallie Morton
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Sudhir Kshirsagar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Arubala P Reddy
- Nutritional Sciences Department, College of Human Sciences, Texas Tech University, 1301 Akron Ave, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Neurology, Department of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Department of Internal Medicine, Cell Biology & Biochemistry, Public Health and School of Health Professions, Texas Tech University Health Sciences Center, Neuroscience & Pharmacology3601 4th Street, NeurologyLubbock, TX, 79430, USA.
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24
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Brustovetsky T, Khanna R, Brustovetsky N. Involvement of CRMP2 in Regulation of Mitochondrial Morphology and Motility in Huntington's Disease. Cells 2021; 10:cells10113172. [PMID: 34831395 PMCID: PMC8619197 DOI: 10.3390/cells10113172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/28/2021] [Accepted: 11/09/2021] [Indexed: 01/29/2023] Open
Abstract
Mitochondrial morphology and motility (mitochondrial dynamics) play a major role in the proper functioning of distant synapses. In Huntington’s disease (HD), mitochondria become fragmented and less motile, but the mechanisms leading to these changes are not clear. Here, we found that collapsin response mediator protein 2 (CRMP2) interacted with Drp1 and Miro 2, proteins involved in regulating mitochondrial dynamics. CRMP2 interaction with these proteins inversely correlated with CRMP2 phosphorylation. CRMP2 was hyperphosphorylated in postmortem brain tissues of HD patients, in human neurons derived from induced pluripotent stem cells from HD patients, and in cultured striatal neurons from HD mouse model YAC128. At the same time, CRMP2 interaction with Drp1 and Miro 2 was diminished in HD neurons. The CRMP2 hyperphosphorylation and dissociation from Drp1 and Miro 2 correlated with increased fission and suppressed motility. (S)-lacosamide ((S)-LCM), a small molecule that binds to CRMP2, decreased its phosphorylation at Thr 509/514 and Ser 522 and rescued CRMP2’s interaction with Drp1 and Miro 2. This was accompanied by reduced mitochondrial fission and enhanced mitochondrial motility. Additionally, (S)-LCM exerted a neuroprotective effect in YAC128 cultured neurons. Thus, our data suggest that CRMP2 may regulate mitochondrial dynamics in a phosphorylation-dependent manner and modulate neuronal survival in HD.
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Affiliation(s)
- Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85721, USA;
- Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Correspondence: ; Tel.: +1-317-278-9229; Fax: +1-317-274-7714
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25
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Hu D, Liu Z, Qi X. Mitochondrial Quality Control Strategies: Potential Therapeutic Targets for Neurodegenerative Diseases? Front Neurosci 2021; 15:746873. [PMID: 34867159 PMCID: PMC8633545 DOI: 10.3389/fnins.2021.746873] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/19/2021] [Indexed: 12/30/2022] Open
Abstract
Many lines of evidence have indicated the therapeutic potential of rescuing mitochondrial integrity by targeting specific mitochondrial quality control pathways in neurodegenerative diseases, such as Parkinson's disease, Huntington's disease, and Alzheimer's disease. In addition to ATP synthesis, mitochondria are critical regulators of ROS production, lipid metabolism, calcium buffering, and cell death. The mitochondrial unfolded protein response, mitochondrial dynamics, and mitophagy are the three main quality control mechanisms responsible for maintaining mitochondrial proteostasis and bioenergetics. The proper functioning of these complex processes is necessary to surveil and restore mitochondrial homeostasis and the healthy pool of mitochondria in cells. Mitochondrial dysfunction occurs early and causally in disease pathogenesis. A significant accumulation of mitochondrial damage resulting from compromised quality control pathways leads to the development of neuropathology. Moreover, genetic or pharmaceutical manipulation targeting the mitochondrial quality control mechanisms can sufficiently rescue mitochondrial integrity and ameliorate disease progression. Thus, therapies that can improve mitochondrial quality control have great promise for the treatment of neurodegenerative diseases. In this review, we summarize recent progress in the field that underscores the essential role of impaired mitochondrial quality control pathways in the pathogenesis of neurodegenerative diseases. We also discuss the translational approaches targeting mitochondrial function, with a focus on the restoration of mitochondrial integrity, including mitochondrial dynamics, mitophagy, and mitochondrial proteostasis.
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Affiliation(s)
- Di Hu
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Zunren Liu
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Xin Qi
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Center for Mitochondrial Disease, Case Western Reserve University School of Medicine, Cleveland, OH, United States
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26
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Nuclear and cytoplasmic huntingtin inclusions exhibit distinct biochemical composition, interactome and ultrastructural properties. Nat Commun 2021; 12:6579. [PMID: 34772920 PMCID: PMC8589980 DOI: 10.1038/s41467-021-26684-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Despite the strong evidence linking the aggregation of the Huntingtin protein (Htt) to the pathogenesis of Huntington's disease (HD), the mechanisms underlying Htt aggregation and neurodegeneration remain poorly understood. Herein, we investigated the ultrastructural properties and protein composition of Htt cytoplasmic and nuclear inclusions in mammalian cells and primary neurons overexpressing mutant exon1 of the Htt protein. Our findings provide unique insight into the ultrastructural properties of cytoplasmic and nuclear Htt inclusions and their mechanisms of formation. We show that Htt inclusion formation and maturation are complex processes that, although initially driven by polyQ-dependent Htt aggregation, also involve the polyQ and PRD domain-dependent sequestration of lipids and cytoplasmic and cytoskeletal proteins related to HD dysregulated pathways; the recruitment and accumulation of remodeled or dysfunctional membranous organelles, and the impairment of the protein quality control and degradation machinery. We also show that nuclear and cytoplasmic Htt inclusions exhibit distinct biochemical compositions and ultrastructural properties, suggesting different mechanisms of aggregation and toxicity.
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27
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Simões RF, Pino R, Moreira-Soares M, Kovarova J, Neuzil J, Travasso R, Oliveira PJ, Cunha-Oliveira T, Pereira FB. Quantitative analysis of neuronal mitochondrial movement reveals patterns resulting from neurotoxicity of rotenone and 6-hydroxydopamine. FASEB J 2021; 35:e22024. [PMID: 34751984 DOI: 10.1096/fj.202100899r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/24/2021] [Accepted: 10/19/2021] [Indexed: 01/31/2023]
Abstract
Alterations in mitochondrial dynamics, including their intracellular trafficking, are common early manifestations of neuronal degeneration. However, current methodologies used to study mitochondrial trafficking events rely on parameters that are primarily altered in later stages of neurodegeneration. Our objective was to establish a reliable applied statistical analysis to detect early alterations in neuronal mitochondrial trafficking. We propose a novel quantitative analysis of mitochondria trajectories based on innovative movement descriptors, including straightness, efficiency, anisotropy, and kurtosis. We evaluated time- and dose-dependent alterations in trajectory descriptors using biological data from differentiated SH-SY5Y cells treated with the mitochondrial toxicants 6-hydroxydopamine and rotenone. MitoTracker Red CMXRos-labelled mitochondria movement was analyzed by total internal reflection fluorescence microscopy followed by computational modelling to describe the process. Based on the aforementioned trajectory descriptors, this innovative analysis of mitochondria trajectories provides insights into mitochondrial movement characteristics and can be a consistent and sensitive method to detect alterations in mitochondrial trafficking occurring in the earliest time points of neurodegeneration.
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Affiliation(s)
- Rui F Simões
- CNC, Center for Neuroscience and Cell Biology, UC Biotech, Cantanhede, Portugal
| | - Rute Pino
- CISUC, Department of Informatics Engineering, University of Coimbra, Coimbra, Portugal
| | - Maurício Moreira-Soares
- OCBE, Faculty of Medicine, University of Oslo, Oslo, Norway.,Centre for Bioinformatics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Jaromira Kovarova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Rui Travasso
- CFisUC, Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Paulo J Oliveira
- CNC, Center for Neuroscience and Cell Biology, UC Biotech, Cantanhede, Portugal
| | | | - Francisco B Pereira
- CISUC, Department of Informatics Engineering, University of Coimbra, Coimbra, Portugal.,Coimbra Polytechnic - ISEC, Coimbra, Portugal
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28
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CRMP2 Is Involved in Regulation of Mitochondrial Morphology and Motility in Neurons. Cells 2021; 10:cells10102781. [PMID: 34685760 PMCID: PMC8535169 DOI: 10.3390/cells10102781] [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: 09/27/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 11/16/2022] Open
Abstract
Regulation of mitochondrial morphology and motility is critical for neurons, but the exact mechanisms are unclear. Here, we demonstrate that these mechanisms may involve collapsin response mediator protein 2 (CRMP2). CRMP2 is attached to neuronal mitochondria and binds to dynamin-related protein 1 (Drp1), Miro 2, and Kinesin 1 light chain (KLC1). Treating neurons with okadaic acid (OA), an inhibitor of phosphatases PP1 and PP2A, resulted in increased CRMP2 phosphorylation at Thr509/514, Ser522, and Thr555, and augmented Drp1 phosphorylation at Ser616. The CRMP2-binding small molecule (S)-lacosamide ((S)-LCM) prevented an OA-induced increase in CRMP2 phosphorylation at Thr509/514 and Ser522 but not at Thr555, and also failed to alleviate Drp1 phosphorylation. The increased CRMP2 phosphorylation correlated with decreased CRMP2 binding to Drp1, Miro 2, and KLC1. (S)-LCM rescued CRMP2 binding to Drp1 and Miro 2 but not to KLC1. In parallel with CRMP2 hyperphosphorylation, OA increased mitochondrial fission and suppressed mitochondrial traffic. (S)-LCM prevented OA-induced alterations in mitochondrial morphology and motility. Deletion of CRMP2 with a small interfering RNA (siRNA) resulted in increased mitochondrial fission and diminished mitochondrial traffic. Overall, our data suggest that the CRMP2 expression level and phosphorylation state are involved in regulating mitochondrial morphology and motility in neurons.
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29
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Bečanović K, Asghar M, Gadawska I, Sachdeva S, Walker D, Lazarowski ER, Franciosi S, Park KHJ, Côté HCF, Leavitt BR. Age-related mitochondrial alterations in brain and skeletal muscle of the YAC128 model of Huntington disease. NPJ Aging Mech Dis 2021; 7:26. [PMID: 34650085 PMCID: PMC8516942 DOI: 10.1038/s41514-021-00079-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 09/16/2021] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial dysfunction and bioenergetics failure are common pathological hallmarks in Huntington's disease (HD) and aging. In the present study, we used the YAC128 murine model of HD to examine the effects of mutant huntingtin on mitochondrial parameters related to aging in brain and skeletal muscle. We have conducted a cross-sectional natural history study of mitochondrial DNA changes in the YAC128 mouse. Here, we first show that the mitochondrial volume fraction appears to increase in the axons and dendrite regions adjacent to the striatal neuron cell bodies in old mice. Mitochondrial DNA copy number (mtDNAcn) was used as a proxy measure for mitochondrial biogenesis and function. We observed that the mtDNAcn changes significantly with age and genotype in a tissue-specific manner. We found a positive correlation between aging and the mtDNAcn in striatum and skeletal muscle but not in cortex. Notably, the YAC128 mice had lower mtDNAcn in cortex and skeletal muscle. We further show that mtDNA deletions are present in striatal and skeletal muscle tissue in both young and aged YAC128 and WT mice. Tracking gene expression levels cross-sectionally in mice allowed us to identify contributions of age and genotype to transcriptional variance in mitochondria-related genes. These findings provide insights into the role of mitochondrial dynamics in HD pathogenesis in both brain and skeletal muscle, and suggest that mtDNAcn in skeletal muscle tissue may be a potential biomarker that should be investigated further in human HD.
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Affiliation(s)
- Kristina Bečanović
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada ,grid.4714.60000 0004 1937 0626Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Muhammad Asghar
- grid.4714.60000 0004 1937 0626Department of Medicine, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden ,grid.24381.3c0000 0000 9241 5705Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Izabella Gadawska
- grid.17091.3e0000 0001 2288 9830Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC Canada
| | - Shiny Sachdeva
- grid.416553.00000 0000 8589 2327The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Disease, St Paul’s Hospital, Vancouver, BC Canada
| | - David Walker
- grid.416553.00000 0000 8589 2327The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Disease, St Paul’s Hospital, Vancouver, BC Canada
| | - Eduardo. R. Lazarowski
- grid.410711.20000 0001 1034 1720Cystic Fibrosis Research Center, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC USA
| | - Sonia Franciosi
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Pediatrics, University of British Columbia, Vancouver, BC Canada
| | - Kevin H. J. Park
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada ,grid.253856.f0000 0001 2113 4110Department of Psychology and Neuroscience Program, Central Michigan University, Mount Pleasant, MI USA
| | - Hélène C. F. Côté
- grid.17091.3e0000 0001 2288 9830Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC Canada
| | - Blair R. Leavitt
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
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30
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Jadiya P, Garbincius JF, Elrod JW. Reappraisal of metabolic dysfunction in neurodegeneration: Focus on mitochondrial function and calcium signaling. Acta Neuropathol Commun 2021; 9:124. [PMID: 34233766 PMCID: PMC8262011 DOI: 10.1186/s40478-021-01224-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023] Open
Abstract
The cellular and molecular mechanisms that drive neurodegeneration remain poorly defined. Recent clinical trial failures, difficult diagnosis, uncertain etiology, and lack of curative therapies prompted us to re-examine other hypotheses of neurodegenerative pathogenesis. Recent reports establish that mitochondrial and calcium dysregulation occur early in many neurodegenerative diseases (NDDs), including Alzheimer's disease, Parkinson's disease, Huntington's disease, and others. However, causal molecular evidence of mitochondrial and metabolic contributions to pathogenesis remains insufficient. Here we summarize the data supporting the hypothesis that mitochondrial and metabolic dysfunction result from diverse etiologies of neuropathology. We provide a current and comprehensive review of the literature and interpret that defective mitochondrial metabolism is upstream and primary to protein aggregation and other dogmatic hypotheses of NDDs. Finally, we identify gaps in knowledge and propose therapeutic modulation of mCa2+ exchange and mitochondrial function to alleviate metabolic impairments and treat NDDs.
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Affiliation(s)
- Pooja Jadiya
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA.
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31
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Groover SE, Adegbuyiro A, Fan CK, Hodges BL, Beasley M, Taylor K, Stonebraker AR, Siriwardhana C, Legleiter J. Macromolecular crowding in solution alters huntingtin interaction and aggregation at interfaces. Colloids Surf B Biointerfaces 2021; 206:111969. [PMID: 34246856 DOI: 10.1016/j.colsurfb.2021.111969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disease caused by an extended polyglutamine (polyQ) domain within the first exon of the huntingtin protein (htt). PolyQ expansion directly invokes the formation of a heterogenous mixture of toxic htt aggregates, including fibrils and oligomers. While htt is a cytosolic protein, it also associates with numerous membranous surfaces within the cell, leading to altered organelle morphology and dysfunction. Here, the impact of macromolecular crowding on htt aggregation in bulk solution and at solid/liquid or membrane/liquid interfaces was investigated. Dextran, Ficoll, and polyethylene glycol (PEG) were used as crowding agents. In bulk solution, crowding enhanced the heterogeneity of non-fibrillar aggregate species formed in a crowder dependent manner. However, crowding agents interfered with the deposition of htt fibrils on mica, suggesting that a crowded aqueous phase influences the interaction of htt with interfaces. By use of in situ atomic force microcopy (AFM), the aggregation of htt directly at mica and bilayer interfaces was tracked. The predominate aggregates type observed to form at the mica interface was fibrillar, but oligomeric aggregates of various stabilities were also observed. Crowding in the aqueous phase suppressed deposition and formation of htt aggregates on mica. In contrast, the addition of crowders enhanced deposition of htt aggregates onto supported total brain lipid extract (TBLE) bilayers. Different crowding agents led to distinct htt aggregates on supported bilayers with unique morphological impact on bilayer integrity. Collectively, these observations point to the complexity of htt aggregation at interfaces and that crowding in the aqueous phase profoundly influences this process.
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Affiliation(s)
- Sharon E Groover
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Breanna L Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Katelyn Taylor
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States.
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32
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Paß T, Wiesner RJ, Pla-Martín D. Selective Neuron Vulnerability in Common and Rare Diseases-Mitochondria in the Focus. Front Mol Biosci 2021; 8:676187. [PMID: 34295920 PMCID: PMC8290884 DOI: 10.3389/fmolb.2021.676187] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/08/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction is a central feature of neurodegeneration within the central and peripheral nervous system, highlighting a strong dependence on proper mitochondrial function of neurons with especially high energy consumptions. The fitness of mitochondria critically depends on preservation of distinct processes, including the maintenance of their own genome, mitochondrial dynamics, quality control, and Ca2+ handling. These processes appear to be differently affected in common neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, as well as in rare neurological disorders, including Huntington’s disease, Amyotrophic Lateral Sclerosis and peripheral neuropathies. Strikingly, particular neuron populations of different morphology and function perish in these diseases, suggesting that cell-type specific factors contribute to the vulnerability to distinct mitochondrial defects. Here we review the disruption of mitochondrial processes in common as well as in rare neurological disorders and its impact on selective neurodegeneration. Understanding discrepancies and commonalities regarding mitochondrial dysfunction as well as individual neuronal demands will help to design new targets and to make use of already established treatments in order to improve treatment of these diseases.
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Affiliation(s)
- Thomas Paß
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - David Pla-Martín
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
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33
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Nicoletti V, Palermo G, Del Prete E, Mancuso M, Ceravolo R. Understanding the Multiple Role of Mitochondria in Parkinson's Disease and Related Disorders: Lesson From Genetics and Protein-Interaction Network. Front Cell Dev Biol 2021; 9:636506. [PMID: 33869180 PMCID: PMC8047151 DOI: 10.3389/fcell.2021.636506] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/16/2021] [Indexed: 12/12/2022] Open
Abstract
As neurons are highly energy-demanding cell, increasing evidence suggests that mitochondria play a large role in several age-related neurodegenerative diseases. Synaptic damage and mitochondrial dysfunction have been associated with early events in the pathogenesis of major neurodegenerative diseases, including Parkinson’s disease, atypical parkinsonisms, and Huntington disease. Disruption of mitochondrial structure and dynamic is linked to increased levels of reactive oxygen species production, abnormal intracellular calcium levels, and reduced mitochondrial ATP production. However, recent research has uncovered a much more complex involvement of mitochondria in such disorders than has previously been appreciated, and a remarkable number of genes and proteins that contribute to the neurodegeneration cascade interact with mitochondria or affect mitochondrial function. In this review, we aim to summarize and discuss the deep interconnections between mitochondrial dysfunction and basal ganglia disorders, with an emphasis into the molecular triggers to the disease process. Understanding the regulation of mitochondrial pathways may be beneficial in finding pharmacological or non-pharmacological interventions to delay the onset of neurodegenerative diseases.
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Affiliation(s)
- Valentina Nicoletti
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Giovanni Palermo
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Eleonora Del Prete
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Michelangelo Mancuso
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberto Ceravolo
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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34
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Fiocchetti M, Cracco P, Montalesi E, Solar Fernandez V, Stuart JA, Marino M. Neuroglobin and mitochondria: The impact on neurodegenerative diseases. Arch Biochem Biophys 2021; 701:108823. [PMID: 33675812 DOI: 10.1016/j.abb.2021.108823] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 12/12/2022]
Abstract
Dysfunctional mitochondria have severe consequences on cell functions including Reactive Oxygen Specie (ROS) generation, alteration of mitochondrial signaling, Ca2+ buffering, and activation of apoptotic pathway. These dysfunctions are closely linked with degenerative diseases including neurodegeneration. The discovery of neuroglobin (NGB) as an endogenous neuroprotective protein, which effects seem to depend on its mitochondrial localization, could drive new therapeutic strategies against aged-related neurodegenerative diseases. Indeed, high levels of NGB are active against several brain injuries, including neurodegeneration, hypoxia, ischemia, toxicity, and nutrient deprivation opening a new scenario in the comprehension of the relationship between neural pathologies and mitochondrial homeostasis. In this review, we provide the current understanding of the role of mitochondria in neurodegeneration and discuss structural and functional connection between NGB and mitochondria with the purpose of defining a novel mitochondrial-based neuroprotective mechanism(s).
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Affiliation(s)
- Marco Fiocchetti
- Department of Science, University Roma Tre, Viale G. Marconi, 446 -00146, Rome, Italy; Neuroendocrinology, Metabolism, and Neuropharmacology Unit, IRCCS Santa Lucia Foundation, 00143, Rome, Italy
| | - Patrizio Cracco
- Department of Science, University Roma Tre, Viale G. Marconi, 446 -00146, Rome, Italy
| | - Emiliano Montalesi
- Department of Science, University Roma Tre, Viale G. Marconi, 446 -00146, Rome, Italy
| | | | - Jeffrey A Stuart
- Department of Biological Science, Faculty of Mathematics and Science, Brock University, St. Catharines L2S 3A1, Ontario, Canada
| | - Maria Marino
- Department of Science, University Roma Tre, Viale G. Marconi, 446 -00146, Rome, Italy; Neuroendocrinology, Metabolism, and Neuropharmacology Unit, IRCCS Santa Lucia Foundation, 00143, Rome, Italy.
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35
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Franco-Iborra S, Plaza-Zabala A, Montpeyo M, Sebastian D, Vila M, Martinez-Vicente M. Mutant HTT (huntingtin) impairs mitophagy in a cellular model of Huntington disease. Autophagy 2021; 17:672-689. [PMID: 32093570 PMCID: PMC8032238 DOI: 10.1080/15548627.2020.1728096] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 01/27/2020] [Accepted: 02/04/2020] [Indexed: 12/13/2022] Open
Abstract
The precise degradation of dysfunctional mitochondria by mitophagy is essential for maintaining neuronal homeostasis. HTT (huntingtin) can interact with numerous other proteins and thereby perform multiple biological functions within the cell. In this study, we investigated the role of HTT during mitophagy and analyzed the impact of the expansion of its polyglutamine (polyQ) tract. HTT is involved in different mitophagy steps, promoting the physical proximity of different protein complexes during the initiation of mitophagy and recruiting mitophagy receptors essential for promoting the interaction between damaged mitochondria and the nascent autophagosome. The presence of the polyQ tract in mutant HTT affects the formation of these protein complexes and determines the negative consequences of mutant HTT on mitophagy, leading to the accumulation of damaged mitochondria and an increase in oxidative stress. These outcomes contribute to general mitochondrial dysfunction and neurodegeneration in Huntington disease.Abbreviations: AMPK: AMP-activated protein kinase; ATG13: autophagy related 13; BECN1: beclin 1, autophagy related; BNIP3: BCL2/adenovirus E1B interacting protein 3; BNIP3L/Nix: BCL2/adenovirus E1B interacting protein 3-like; CCCP: carbonyl cyanide 3-chlorophenyl hydrazone; DMEM: Dulbecco's modified eagle medium; EDTA: ethylene-diamine-tetra-acetic acid; EGFP: enhanced green fluorescent protein; EGTA: ethylene glycol bis(2-aminoethyl ether)tetraacetic acid; FUNDC1: FUN14 domain containing 1; HD: Huntington disease; HRP: horseradish peroxidase; HTT: huntingtin; LC3-II: lipidated form of MAP1LC3/LC3; mtDNA: mitochondrial deoxyribonucleic acid; MTDR: MitoTracker Deep Red; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; NBR1: NBR1, autophagy cargo receptor; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; OCR: oxygen consumption rate; OPTN: optineurin; OXPHOS: oxidative phosphorylation; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3R4/VPS15: phosphoinositide-3-kinase regulatory subunit 4; PINK1: PTEN induced putative kinase 1; PLA: proximity ligation assay; PMSF: phenylmethylsulfonyl fluoride; polyQ: polyglutamine; PtdIns3K: phosphatidylinositol 3-kinase; ROS: reactive oxygen species; Rot: rotenone; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; SEM: standard error of the mean; SQSTM1/p62: sequestosome 1; TMRM: tetramethylrhodamine methyl ester; UB: ubiquitin; ULK1: unc-51 like kinase 1.
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Affiliation(s)
- Sandra Franco-Iborra
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute-Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED)-Autonomous University of Barcelona, Barcelona, Spain
| | - Ainhoa Plaza-Zabala
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute-Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED)-Autonomous University of Barcelona, Barcelona, Spain
| | - Marta Montpeyo
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute-Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED)-Autonomous University of Barcelona, Barcelona, Spain
| | - David Sebastian
- Institute for Research in Biomedicine (IRB) - Diabetes and Associated Metabolic Diseases Networking Biomedical Research (CIBERDEM), Barcelona, Spain
| | - Miquel Vila
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute-Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED)-Autonomous University of Barcelona, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Autonomous University of Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Marta Martinez-Vicente
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute-Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED)-Autonomous University of Barcelona, Barcelona, Spain
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36
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Choi GE, Han HJ. Glucocorticoid impairs mitochondrial quality control in neurons. Neurobiol Dis 2021; 152:105301. [PMID: 33609641 DOI: 10.1016/j.nbd.2021.105301] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/20/2021] [Accepted: 02/14/2021] [Indexed: 12/17/2022] Open
Abstract
Neurons are particularly vulnerable to mitochondrial dysfunction due to high energy demand and an inability to proliferate. Therefore, dysfunctional mitochondria cause various neuropathologies. Mitochondrial damage induces maintenance pathways to repair or eliminate damaged organelles. This mitochondrial quality control (MQC) system maintains appropriate morphology, localization, and removal/replacement of mitochondria to sustain brain homeostasis and counter progression of neurological disorders. Glucocorticoid release is an essential response to stressors for adaptation; however, it often culminates in maladaptation if neurons are exposed to chronic and severe stress. Long-term exposure to high levels of glucocorticoids induces mitochondrial dysfunction via genomic and nongenomic mechanisms. Glucocorticoids induce abnormal mitochondrial morphology and dysregulate fusion and fission. Moreover, mitochondrial trafficking is arrested by glucocorticoids and dysfunctional mitochondria are subsequently accumulated around the soma. These alterations lead to energy deficiency, particularly for synaptic transmission that requires large amounts of energy. Glucocorticoids also impair mitochondrial clearance by preventing mitophagy of damaged organelle and suppress mitochondrial biogenesis, resulting in the reduced number of healthy mitochondria. Failure to maintain MQC degrades brain function and contributes to neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. However, mechanisms of glucocorticoid action on the regulation of MQC during chronic stress conditions are not well understood. The present review discusses pathways involved in the impairment of MQC and the clinical significance of high glucocorticoid blood levels for neurodegenerative diseases.
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Affiliation(s)
- Gee Euhn Choi
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul 08826, Republic of Korea.
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Chen YC, Huang HR, Hsu CH, Ou CY. CRMP/UNC-33 organizes microtubule bundles for KIF5-mediated mitochondrial distribution to axon. PLoS Genet 2021; 17:e1009360. [PMID: 33571181 PMCID: PMC7904166 DOI: 10.1371/journal.pgen.1009360] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 02/24/2021] [Accepted: 11/11/2020] [Indexed: 12/13/2022] Open
Abstract
Neurons are highly specialized cells with polarized cellular processes and subcellular domains. As vital organelles for neuronal functions, mitochondria are distributed by microtubule-based transport systems. Although the essential components of mitochondrial transport including motors and cargo adaptors are identified, it is less clear how mitochondrial distribution among somato-dendritic and axonal compartment is regulated. Here, we systematically study mitochondrial motors, including four kinesins, KIF5, KIF17, KIF1, KLP-6, and dynein, and transport regulators in C. elegans PVD neurons. Among all these motors, we found that mitochondrial export from soma to neurites is mainly mediated by KIF5/UNC-116. Interestingly, UNC-116 is especially important for axonal mitochondria, while dynein removes mitochondria from all plus-end dendrites and the axon. We surprisingly found one mitochondrial transport regulator for minus-end dendritic compartment, TRAK-1, and two mitochondrial transport regulators for axonal compartment, CRMP/UNC-33 and JIP3/UNC-16. While JIP3/UNC-16 suppresses axonal mitochondria, CRMP/UNC-33 is critical for axonal mitochondria; nearly no axonal mitochondria present in unc-33 mutants. We showed that UNC-33 is essential for organizing the population of UNC-116-associated microtubule bundles, which are tracks for mitochondrial trafficking. Disarrangement of these tracks impedes mitochondrial transport to the axon. In summary, we identified a compartment-specific transport regulation of mitochondria by UNC-33 through organizing microtubule tracks for different kinesin motors other than microtubule polarity.
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Affiliation(s)
- Ying-Chun Chen
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hao-Ru Huang
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Hao Hsu
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chan-Yen Ou
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Labanca F, Ullah H, Khan H, Milella L, Xiao J, Dajic-Stevanovic Z, Jeandet P. Therapeutic and Mechanistic Effects of Curcumin in Huntington's Disease. Curr Neuropharmacol 2021; 19:1007-1018. [PMID: 32442088 PMCID: PMC8686321 DOI: 10.2174/1570159x18666200522201123] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/10/2020] [Accepted: 05/17/2020] [Indexed: 02/08/2023] Open
Abstract
Curcumin is a spice derived nutraceutical which gained tremendous attention because of its profound medicinal values. It alters a number of molecular pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), signal transducer and activator of transcription 3 (STAT3), nuclear factor erythroid 2-related factor 2 (Nrf2) and cyclooxygenases-2 (COX-2), which make it potential therapeutic choice in treating multiple disorders. It also possesses the potential to prevent protein aggregation and thus protect against degeneration of neurons in neurodegenerative disorders including Huntington's disease (HD). HD is an autosomal dominant disorder linked with altered gene expression which leads to an increase in the size of cytosine, adenine and guanine (CAG) trinucleotide repeats, aids in protein aggregation throughout the brain and thus damages neurons. Upstream regulation of oxidative stress and inflammatory cascade are two important factors that drive HD progression. Available therapies just suppress the severity of symptoms with a number of side effects. Curcumin targets multiple mechanisms in treating or preventing HD including antioxidant and anti-inflammatory potential, metal ion chelation, transcriptional alterations and upregulating activity of molecular chaperons, heat shock proteins (HSPs). Having a favorable safety profile, curcumin can be an alternative therapeutic choice in treating neurodegenerative disorders like HD. This review will focus on mechanistic aspects of curcumin in treating or preventing HD and its potential to arrest disease progression and will open new dimensions for safe and effective therapeutic agents in diminishing HD.
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Affiliation(s)
| | | | - Haroon Khan
- Address correspondence to this author at the Department of Pharmacy, Abdul Wali Khan University Mardan, 23200, Pakistan;, E-mails: ;
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Dafinca R, Barbagallo P, Talbot K. The Role of Mitochondrial Dysfunction and ER Stress in TDP-43 and C9ORF72 ALS. Front Cell Neurosci 2021; 15:653688. [PMID: 33867942 PMCID: PMC8047135 DOI: 10.3389/fncel.2021.653688] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/10/2021] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the motor system with complex determinants, including genetic and non-genetic factors. Despite this heterogeneity, a key pathological signature is the mislocalization and aggregation of specific proteins in the cytoplasm, suggesting that convergent pathogenic mechanisms focusing on disturbances in proteostasis are important in ALS. In addition, many cellular processes have been identified as potentially contributing to disease initiation and progression, such as defects in axonal transport, autophagy, nucleocytoplasmic transport, ER stress, calcium metabolism, the unfolded protein response and mitochondrial function. Here we review the evidence from in vitro and in vivo models of C9ORF72 and TDP-43-related ALS supporting a central role in pathogenesis for endoplasmic reticulum stress, which activates an unfolded protein response (UPR), and mitochondrial dysfunction. Disruption in the finely tuned signaling between the ER and mitochondria through calcium ions may be a crucial trigger of mitochondrial deficits and initiate an apoptotic signaling cascade, thus acting as a point of convergence for multiple upstream disturbances of cellular homeostasis and constituting a potentially important therapeutic target.
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40
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Masnata M, Salem S, de Rus Jacquet A, Anwer M, Cicchetti F. Targeting Tau to Treat Clinical Features of Huntington's Disease. Front Neurol 2020; 11:580732. [PMID: 33329322 PMCID: PMC7710872 DOI: 10.3389/fneur.2020.580732] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/17/2020] [Indexed: 12/16/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by severe motor, cognitive and psychiatric impairments. While motor deficits often confirm diagnosis, cognitive dysfunctions usually manifest early in the disease process and are consistently ranked among the leading factors that impact the patients' quality of life. The genetic component of HD, a mutation in the huntingtin (HTT) gene, is traditionally presented as the main contributor to disease pathology. However, accumulating evidence suggests the implication of the microtubule-associated tau protein to the pathogenesis and therefore, proposes an alternative conceptual framework where tau and mutant huntingtin (mHTT) act conjointly to drive neurodegeneration and cognitive dysfunction. This perspective on disease etiology offers new avenues to design therapeutic interventions and could leverage decades of research on Alzheimer's disease (AD) and other tauopathies to rapidly advance drug discovery. In this mini review, we examine the breadth of tau-targeting treatments currently tested in the preclinical and clinical settings for AD and other tauopathies, and discuss the potential application of these strategies to HD.
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Affiliation(s)
- Maria Masnata
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Shireen Salem
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | - Aurelie de Rus Jacquet
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Mehwish Anwer
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
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Zorgniotti A, Ditamo Y, Arce CA, Bisig CG. Irreversible incorporation of L-dopa into the C-terminus of α-tubulin inhibits binding of molecular motor KIF5B to microtubules and alters mitochondrial traffic along the axon. Neurobiol Dis 2020; 147:105164. [PMID: 33171229 DOI: 10.1016/j.nbd.2020.105164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022] Open
Abstract
L-dopa is the most effective drug used to date for management of Parkinson's disease symptoms. Unfortunately, long-term administration of L-dopa often results in development of motor disorders, including dyskinesias. Despite extensive research on L-dopa-induced dyskinesia, its pathogenesis remains poorly understood. We demonstrated previously that L-dopa can be post-translationally incorporated into the C-terminus of α-tubulin in living cells. In the present study, we investigated the effect of the presence of L-dopa-tubulin-enriched microtubules on mitochondrial traffic mediated by molecular motor KIF5B. Using biochemical approaches in combination with experiments on neuronal cell lines and mouse hippocampal primary cultures, we demonstrated that L-dopa incorporation into tubulin is irreversible. Transport of mitochondria along the axon was altered after L-dopa treatment of cells. In L-dopa-treated cells, mitochondria had reduced ability to reach the distal segment of the axon, spent more time in pause, and showed reduced velocity of anterograde movement. KIF5B motor, a member of the kinesin family involved in mitochondrial transport in neurons, showed reduced affinity for Dopa-tubulin-containing microtubules. Our findings, taken together, suggest that tyrosination state of tubulin (and microtubules) is altered by L-dopa incorporation into tubulin; the gradual increase in amount of altered microtubules affects microtubule functioning, impairs mitochondrial traffic and distribution, and this could be relevant in Parkinson's disease patients chronically treated with L-dopa.
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Affiliation(s)
- Agustina Zorgniotti
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina
| | - Yanina Ditamo
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina
| | - Carlos A Arce
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina
| | - C Gaston Bisig
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
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Lipid headgroups alter huntingtin aggregation on membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183497. [PMID: 33130095 DOI: 10.1016/j.bbamem.2020.183497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022]
Abstract
Huntington's Disease is a fatal neurodegenerative disorder caused by expansion of a glutamine repeat region (polyQ) beyond a critical threshold within exon1 of the huntingtin protein (htt). As a consequence of polyQ expansion, htt associates into a variety of aggregate species that are thought to underlie cellular toxicity. Within cells, htt associates with numerous membranous organelles and surfaces that exert influence on the aggregation process. In particular, the first 17 amino acids at the N-terminus of htt (Nt17) serve as a lipid-binding domain that is intrinsically disordered in bulk solution but adopts an amphipathic α-helical structure upon binding membranes. Beyond this, Nt17 is implicated in initiating htt fibrillization. As the interaction between Nt17 and lipid membranes is likely influenced by lipid properties, the impact of lipid headgroups on htt-exon1 aggregation, membrane activity, and the ability to form protein:lipid complexes was determined. Htt-exon1 with a disease-length polyQ domain (46Q) was exposed to lipid vesicles comprised of lipids with either zwitterionic (POPC and POPE) or anionic (POPG and POPS) headgroups. With zwitterionic head groups, large lipid to peptide ratios were required to have a statistically significant impact on htt aggregation. Anionic lipids enhanced htt fibrillization, even at low lipid:protein ratios, and this was accompanied by changes in aggregate morphology. Despite the larger impact of anionic lipids, htt-exon1(46Q) was more membrane active with zwitterionic lipid systems. The ability of Nt17 to form complexes with lipids was also mediated by lipid headgroups as zwitterionic ionic lipids more readily associated with multimeric forms of Nt17 in comparison with anionic lipids. Collectively, these results highlight the complexity of htt/membrane interactions and the resulting impact on the aggregation process.
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43
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Park SJ, Choi JW. Brain energy metabolism and multiple sclerosis: progress and prospects. Arch Pharm Res 2020; 43:1017-1030. [PMID: 33119885 DOI: 10.1007/s12272-020-01278-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
Multiple sclerosis (MS) is an autoimmune disease accompanied with nerve pain and paralysis. Although various pathogenic causes of MS have been suggested, including genetic and environmental factors, how MS occurs remains unclear. Moreover, MS should be diagnosed based on clinical experiences because of no disease-specific biomarker and currently available treatments for MS just can reduce relapsing frequency or severity with little effects on disease disability. Therefore, more efforts are required to identify pathophysiology of MS and diagnosis markers. Recent evidence indicates another aspect of MS pathogenesis, energy failure in the central nervous system (CNS). For instance, inflammation that is a characteristic MS symptom and occurs frequently in the CNS of MS patients can result into energy failure in mitochondria and cytosol. Indeed, metabolomics studies for MS have reported energy failure in oxidative phosphorylation and alteration of aerobic glycolysis. Therefore, studies on the metabolism in the CNS may provide another insight for understanding complexity of MS and pathogenesis, which would facilitate the discovery of promising strategies for developing therapeutics to treat MS. This review will provide an overview on recent progress of metabolomic studies for MS, with a focus on the fluctuation of energy metabolism in MS.
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Affiliation(s)
- Sung Jean Park
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon, 21936, Korea.
| | - Ji Woong Choi
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon, 21936, Korea.
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44
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Theocharopoulou G. The ubiquitous role of mitochondria in Parkinson and other neurodegenerative diseases. AIMS Neurosci 2020; 7:43-65. [PMID: 32455165 PMCID: PMC7242057 DOI: 10.3934/neuroscience.2020004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/05/2020] [Indexed: 12/14/2022] Open
Abstract
Orderly mitochondrial life cycle, plays a key role in the pathology of neurodegenerative diseases. Mitochondria are ubiquitous in neurons as they respond to an ever-changing demand for energy supply. Mitochondria constantly change in shape and location, feature of their dynamic nature, which facilitates a quality control mechanism. Biological studies in mitochondria dynamics are unveiling the mechanisms of fission and fusion, which essentially arrange morphology and motility of these organelles. Control of mitochondrial network homeostasis is a critical factor for the proper function of neurons. Disease-related genes have been reported to be implicated in mitochondrial dysfunction. Increasing evidence implicate mitochondrial perturbation in neuronal diseases, such as AD, PD, HD, and ALS. The intricacy involved in neurodegenerative diseases and the dynamic nature of mitochondria point to the idea that, despite progress toward detecting the biology underlying mitochondrial disorders, its link to these diseases is difficult to be identified in the laboratory. Considering the need to model signaling pathways, both in spatial and temporal level, there is a challenge to use a multiscale modeling framework, which is essential for understanding the dynamics of a complex biological system. The use of computational models in order to represent both a qualitative and a quantitative structure of mitochondrial homeostasis, allows to perform simulation experiments so as to monitor the conformational changes, as well as the intersection of form and function.
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45
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Sivanesan S, Chang E, Howell MD, Rajadas J. Amyloid protein aggregates: new clients for mitochondrial energy production in the brain? FEBS J 2020; 287:3386-3395. [DOI: 10.1111/febs.15225] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/08/2020] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Senthilkumar Sivanesan
- Biomaterials and Advanced Drug Delivery Laboratory Cardiovascular Institute Stanford University School of Medicine Stanford CA USA
| | - Edwin Chang
- Department of Radiology Stanford University School of Medicine Stanford CA USA
| | | | - Jayakumar Rajadas
- Biomaterials and Advanced Drug Delivery Laboratory Cardiovascular Institute Stanford University School of Medicine Stanford CA USA
- Department of Bioengineering and Therapeutic Sciences School of Pharmacy University of California San Francisco San Francisco CA USA
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46
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Sedighi F, Adegbuyiro A, Legleiter J. SUMOylation Prevents Huntingtin Fibrillization and Localization onto Lipid Membranes. ACS Chem Neurosci 2020; 11:328-343. [PMID: 31880908 DOI: 10.1021/acschemneuro.9b00509] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD), a genetic neurodegenerative disease, is caused by an expanded polyglutamine (polyQ) domain in the first exon of the huntingtin protein (htt). PolyQ expansion destabilizes protein structure, resulting in aggregation into a variety of oligomers, protofibrils, and fibrils. Beyond the polyQ domain, adjacent protein sequences influence the aggregation process. Specifically, the first 17 N-terminal amino acids (Nt17) directly preceding the polyQ domain promote the formation of α-helix-rich oligomers that represent intermediate species associated with fibrillization. Due to its propensity to form an amphipathic α-helix, Nt17 also facilitates lipid binding. Three lysine residues (K6, K9, and K15) within Nt17 can be SUMOylated, which modifies htt's accumulation and toxicity within cells in a variety of HD models. The impact of SUMOylation on htt aggregation and direct interaction with lipid membranes was investigated. SUMOylation of htt-exon1 inhibited fibril formation while promoting larger, amorphous aggregate species. These amorphous aggregates were SDS soluble but nonetheless exhibited levels of β-sheet structure similar to that of htt-exon1 fibrils. In addition, SUMOylation prevented htt binding, aggregation, and accumulation on model lipid bilayers comprised of total brain lipid extract. Collectively, these observations demonstrate that SUMOylation promotes a distinct htt aggregation pathway that may affect htt toxicity.
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Affiliation(s)
- Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
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47
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Tereshchenko A, van der Plas E, Mathews KD, Epping E, Conrad AL, Langbehn DR, Nopoulos P. Developmental Trajectory of Height, Weight, and BMI in Children and Adolescents at Risk for Huntington's Disease: Effect of mHTT on Growth. J Huntingtons Dis 2020; 9:245-251. [PMID: 32894247 PMCID: PMC7683066 DOI: 10.3233/jhd-200407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The gene (Huntingtin or HTT) causing Huntington's disease (HD) is vital for development and is expressed throughout the brain and body lifelong. The mutant form (mHTT) may influence growth and development. OBJECTIVE To determine the impact of mHTT on human measures of growth, including height, weight, and body mass index (BMI), between child and adolescent carriers of mHTT and control peers. METHODS Children ages 6-18 years of age (n = 186) at risk for HD were enrolled in the KidsHD study. For research purposes only, genetic testing was performed to classify participants as Gene-Expanded (GE = 78) or as Gene Non-Expanded (GNE = 108). Outcome measures included height, weight, and body mass index (BMI). Mixed models were used to determine if non-linear age trends differed between groups for BMI, height, and weight. RESULTS Differences were seen in the trajectory of BMI in which the GE group reached a plateau in late adolescence with no further increase, compared with a nearly linear increase in the GNE group. There was a significant sex interaction pattern where GE males were taller than GNE males in adolescence, in the presence of similar weight. In contrast, GE females weighed significantly less than their GNE counterparts in adolescence, in the presence of similar height. CONCLUSION Measures of growth are abnormal in child and adolescent carriers of mHTT, decades before HD onset. Although further studies are needed for replication, the current findings suggest that developmental aberrations may be systemic and a vital part of disease pathology.
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Affiliation(s)
- Alexander Tereshchenko
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Ellen van der Plas
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Katherine D. Mathews
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Eric Epping
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Amy L. Conrad
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Douglas R. Langbehn
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
- University of Iowa College of Public Health Administration, Iowa City, IA, USA
| | - Peg Nopoulos
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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48
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Beasley M, Stonebraker AR, Hasan I, Kapp KL, Liang BJ, Agarwal G, Groover S, Sedighi F, Legleiter J. Lipid Membranes Influence the Ability of Small Molecules To Inhibit Huntingtin Fibrillization. Biochemistry 2019; 58:4361-4373. [PMID: 31608620 DOI: 10.1021/acs.biochem.9b00739] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Several diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease (HD), are associated with specific proteins aggregating and depositing within tissues and/or cellular compartments. The aggregation of these proteins is characterized by the formation of extended, β-sheet rich fibrils, termed amyloid. In addition, a variety of other aggregate species also form, including oligomers and protofibrils. Specifically, HD is caused by the aggregation of the huntingtin (htt) protein that contains an expanded polyglutamine domain. Due to the link between protein aggregation and disease, small molecule aggregation inhibitors have been pursued as potential therapeutic agents. Two such small molecules are epigallocatechin 3-gallate (EGCG) and curcumin, both of which inhibit the fibril formation of several amyloid-forming proteins. However, amyloid formation is a complex process that is strongly influenced by the protein's environment, leading to distinct aggregation pathways. Thus, changes in the protein's environment may alter the effectiveness of aggregation inhibitors. A well-known modulator of amyloid formation is lipid membranes. Here, we investigated if the presence of lipid vesicles altered the ability of EGCG or curcumin to modulate htt aggregation and influence the interaction of htt with lipid membranes. The presence of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine or total brain lipid extract vesicles prevented the curcumin from inhibiting htt fibril formation. In contrast, EGCG's inhibition of htt fibril formation persisted in the presence of lipids. Collectively, these results highlight the complexity of htt aggregation and demonstrate that the presence of lipid membranes is a key modifier of the ability of small molecules to inhibit htt fibril formation.
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Affiliation(s)
- Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Iraj Hasan
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Kathryn L Kapp
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Barry J Liang
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Garima Agarwal
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States.,Rockefeller Neurosciences Institute , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States.,Department of Neuroscience , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States
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49
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Creus-Muncunill J, Ehrlich ME. Cell-Autonomous and Non-cell-Autonomous Pathogenic Mechanisms in Huntington's Disease: Insights from In Vitro and In Vivo Models. Neurotherapeutics 2019; 16:957-978. [PMID: 31529216 PMCID: PMC6985401 DOI: 10.1007/s13311-019-00782-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominant disorder caused by an expansion in the trinucleotide CAG repeat in exon-1 in the huntingtin gene, located on chromosome 4. When the number of trinucleotide CAG exceeds 40 repeats, disease invariably is manifested, characterized by motor, cognitive, and psychiatric symptoms. The huntingtin (Htt) protein and its mutant form (mutant huntingtin, mHtt) are ubiquitously expressed but although multiple brain regions are affected, the most vulnerable brain region is the striatum. Striatal medium-sized spiny neurons (MSNs) preferentially degenerate, followed by the cortical pyramidal neurons located in layers V and VI. Proposed HD pathogenic mechanisms include, but are not restricted to, excitotoxicity, neurotrophic support deficits, collapse of the protein degradation mechanisms, mitochondrial dysfunction, transcriptional alterations, and disorders of myelin. Studies performed in cell type-specific and regionally selective HD mouse models implicate both MSN cell-autonomous properties and cell-cell interactions, particularly corticostriatal but also with non-neuronal cell types. Here, we review the intrinsic properties of MSNs that contribute to their selective vulnerability and in addition, we discuss how astrocytes, microglia, and oligodendrocytes, together with aberrant corticostriatal connectivity, contribute to HD pathophysiology. In addition, mHtt causes cell-autonomous dysfunction in cell types other than MSNs. These findings have implications in terms of therapeutic strategies aimed at preventing neuronal dysfunction and degeneration.
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Affiliation(s)
- Jordi Creus-Muncunill
- Department of Neurology, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA.
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Energy Metabolism and Mitochondrial Superoxide Anion Production in Pre-symptomatic Striatal Neurons Derived from Human-Induced Pluripotent Stem Cells Expressing Mutant Huntingtin. Mol Neurobiol 2019; 57:668-684. [PMID: 31435904 DOI: 10.1007/s12035-019-01734-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/15/2019] [Indexed: 12/13/2022]
Abstract
In the present study, we investigated whether mutant huntingtin (mHTT) impairs mitochondrial functions in human striatal neurons derived from induced pluripotent stem cells (iPSCs). Striatal neurons and astrocytes derived from iPSCs from unaffected individuals (Ctrl) and Huntington's disease (HD) patients with HTT gene containing increased number of CAG repeats were used to assess the effect of mHTT on bioenergetics and mitochondrial superoxide anion production. The human neurons were thoroughly characterized and shown to express MAP2, DARPP32, GABA, synapsin, and PSD95. In human neurons and astrocytes expressing mHTT, the ratio of mHTT to wild-type huntingtin (HTT) was 1:1. The human neurons were excitable and could generate action potentials, confirming successful conversion of iPSCs into functional neurons. The neurons and astrocytes from Ctrl individuals and HD patients had similar levels of ADP and ATP and comparable respiratory and glycolytic activities. The mitochondrial mass, mitochondrial membrane potential, and superoxide anion production in human neurons appeared to be similar regardless of mHTT presence. The present results are in line with the results obtained in our previous studies with isolated brain mitochondria and cultured striatal neurons from YAC128 and R6/2 mice, in which we demonstrated that mutant huntingtin at early stages of HD pathology does not deteriorate mitochondrial functions. Overall, our results argue against bioenergetic deficits as a factor in HD pathogenesis and suggest that other detrimental processes might be more relevant to the development of HD pathology.
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