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Wang Y, Yang J. ER-organelle contacts: A signaling hub for neurological diseases. Pharmacol Res 2024; 203:107149. [PMID: 38518830 DOI: 10.1016/j.phrs.2024.107149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 03/07/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
Neuronal health is closely linked to the homeostasis of intracellular organelles, and organelle dysfunction affects the pathological progression of neurological diseases. In contrast to isolated cellular compartments, a growing number of studies have found that organelles are largely interdependent structures capable of communicating through membrane contact sites (MCSs). MCSs have been identified as key pathways mediating inter-organelle communication crosstalk in neurons, and their alterations have been linked to neurological disease pathology. The endoplasmic reticulum (ER) is a membrane-bound organelle capable of forming an extensive network of pools and tubules with important physiological functions within neurons. There are multiple MCSs between the ER and other organelles and the plasma membrane (PM), which regulate a variety of cellular processes. In this review, we focus on ER-organelle MCSs and their role in a variety of neurological diseases. We compared the biological effects between different tethering proteins and the effects of their respective disease counterparts. We also discuss how altered ER-organelle contacts may affect disease pathogenesis. Therefore, understanding the molecular mechanisms of ER-organelle MCSs in neuronal homeostasis will lay the foundation for the development of new therapies targeting ER-organelle contacts.
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Affiliation(s)
- Yunli Wang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, PR China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, PR China
| | - Jinghua Yang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, PR China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, PR China.
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2
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Martinello C, Panza E, Orlacchio A. Hereditary spastic paraplegias proteome: common pathways and pathogenetic mechanisms. Expert Rev Proteomics 2023; 20:171-188. [PMID: 37788157 DOI: 10.1080/14789450.2023.2260952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023]
Abstract
INTRODUCTION Hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative disorders characterized by progressive spasticity and weakness of the lower limbs. These conditions are caused by lesions in the neuronal pyramidal tract and exhibit clinical and genetic variability. Ongoing research focuses on understanding the underlying mechanisms of HSP onset, which ultimately lead to neuronal degeneration. Key molecular mechanisms involved include axonal transport, cytoskeleton dynamics, myelination abnormalities, membrane trafficking, organelle morphogenesis, ER homeostasis, mitochondrial dysfunction, and autophagy deregulation. AREAS COVERED This review aims to provide an overview of the shared pathogenetic mechanisms in various forms of HSPs. By examining disease-causing gene products and their associated functional pathways, this understanding could lead to the discovery of new therapeutic targets and the development of treatments to modify the progression of the disease. EXPERT OPINION Investigating gene functionality is crucial for identifying shared pathogenetic pathways underlying different HSP subtypes. Categorizing protein function and identifying pathways aids in finding biomarkers, predicting early onset, and guiding treatment for a better quality of life. Targeting shared mechanisms enables efficient and cost-effective therapies. Prospects involve identifying new disease-causing genes, refining molecular processes, and implementing findings in diagnosis, key for advancing HSP understanding and developing effective treatments.
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Affiliation(s)
- Chiara Martinello
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
| | - Emanuele Panza
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
- Unità di Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Antonio Orlacchio
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
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3
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Ho NJ, Chen X, Lei Y, Gu S. Decoding hereditary spastic paraplegia pathogenicity through transcriptomic profiling. Zool Res 2023; 44:650-662. [PMID: 37161652 PMCID: PMC10236304 DOI: 10.24272/j.issn.2095-8137.2022.281] [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: 12/30/2022] [Accepted: 05/10/2023] [Indexed: 05/11/2023] Open
Abstract
Hereditary spastic paraplegia (HSP) is a group of genetic motor neuron diseases resulting from length-dependent axonal degeneration of the corticospinal upper motor neurons. Due to the advancement of next-generation sequencing, more than 70 novel HSP disease-causing genes have been identified in the past decade. Despite this, our understanding of HSP physiopathology and the development of efficient management and treatment strategies remain poor. One major challenge in studying HSP pathogenicity is selective neuronal vulnerability, characterized by the manifestation of clinical symptoms that are restricted to specific neuronal populations, despite the presence of germline disease-causing variants in every cell of the patient. Furthermore, disease genes may exhibit ubiquitous expression patterns and involve a myriad of different pathways to cause motor neuron degeneration. In the current review, we explore the correlation between transcriptomic data and clinical manifestations, as well as the importance of interspecies models by comparing tissue-specific transcriptomic profiles of humans and mice, expression patterns of different genes in the brain during development, and single-cell transcriptomic data from related tissues. Furthermore, we discuss the potential of emerging single-cell RNA sequencing technologies to resolve unanswered questions related to HSP pathogenicity.
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Affiliation(s)
- Nicolas James Ho
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiao Chen
- Dr. Li Dak Sum-Yip Yio Chin Center for Stem Cells and Regenerative Medicine and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Zhejiang University-University of Edinburgh Institute & School of Basic Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Sports Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou, Zhejiang, 310058 China
| | - Yong Lei
- School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen, Guangdong 518172, China
- The Chinese University of Hong Kong (Shenzhen), Shenzhen Futian Biomedical Innovation R&D Center, Shenzhen, Guangdong 518172, China. E-mail:
| | - Shen Gu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
- Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
- Kunming Institute of Zoology Chinese Academy of Sciences, The Chinese University of Hong Kong Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Hong Kong SAR, China
- Hong Kong Branch of CAS Center for Excellence in Animal Evolution and Genetics, The Chinese University of Hong Kong, Hong Kong SAR, China. E-mail:
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4
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Lu M, Christensen CN, Weber JM, Konno T, Läubli NF, Scherer KM, Avezov E, Lio P, Lapkin AA, Kaminski Schierle GS, Kaminski CF. ERnet: a tool for the semantic segmentation and quantitative analysis of endoplasmic reticulum topology. Nat Methods 2023; 20:569-579. [PMID: 36997816 DOI: 10.1038/s41592-023-01815-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 02/10/2023] [Indexed: 04/01/2023]
Abstract
The ability to quantify structural changes of the endoplasmic reticulum (ER) is crucial for understanding the structure and function of this organelle. However, the rapid movement and complex topology of ER networks make this challenging. Here, we construct a state-of-the-art semantic segmentation method that we call ERnet for the automatic classification of sheet and tubular ER domains inside individual cells. Data are skeletonized and represented by connectivity graphs, enabling precise and efficient quantification of network connectivity. ERnet generates metrics on topology and integrity of ER structures and quantifies structural change in response to genetic or metabolic manipulation. We validate ERnet using data obtained by various ER-imaging methods from different cell types as well as ground truth images of synthetic ER structures. ERnet can be deployed in an automatic high-throughput and unbiased fashion and identifies subtle changes in ER phenotypes that may inform on disease progression and response to therapy.
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Affiliation(s)
- Meng Lu
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK
| | - Charles N Christensen
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Artificial Intelligence Group, Department of Computer Science and Technology, University of Cambridge, Cambridge, UK
| | - Jana M Weber
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Delft Bioinformatics Lab, Intelligent Systems Department, Delft University of Technology, Delft, the Netherlands
| | - Tasuku Konno
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Nino F Läubli
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Katharina M Scherer
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Edward Avezov
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Pietro Lio
- Artificial Intelligence Group, Department of Computer Science and Technology, University of Cambridge, Cambridge, UK
| | - Alexei A Lapkin
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Gabriele S Kaminski Schierle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
- Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, UK.
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5
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The interconnection of endoplasmic reticulum and microtubule and its implication in Hereditary Spastic Paraplegia. Comput Struct Biotechnol J 2023; 21:1670-1677. [PMID: 36860342 PMCID: PMC9968982 DOI: 10.1016/j.csbj.2023.02.025] [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: 08/15/2022] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
The endoplasmic reticulum (ER) and microtubule (MT) network form extensive contact with each other and their interconnection plays a pivotal role in ER maintenance and distribution as well as MT stability. The ER participates in a variety of biological processes including protein folding and processing, lipid biosynthesis, and Ca2+ storage. MTs specifically regulate cellular architecture, provide routes for transport of molecules or organelles, and mediate signaling events. The ER morphology and dynamics are regulated by a class of ER shaping proteins, which also provide the physical contact structure for linking of ER and MT. In addition to these ER-localized and MT-binding proteins, specific motor proteins and adaptor-linking proteins also mediate bidirectional communication between the two structures. In this review, we summarize the current understanding of the structure and function of ER-MT interconnection. We further highlight the morphologic factors which coordinate the ER-MT network and maintain the normal physiological function of neurons, with their defect causing neurodegenerative diseases such as Hereditary Spastic Paraplegia (HSP). These findings promote our understanding of the pathogenesis of HSP and provide important therapeutic targets for treatment of these diseases.
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6
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Molecular machinery regulating organelle dynamics during axon growth and guidance. Semin Cell Dev Biol 2023; 133:3-9. [PMID: 35227625 DOI: 10.1016/j.semcdb.2022.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/24/2022] [Accepted: 02/21/2022] [Indexed: 11/23/2022]
Abstract
Axon growth and guidance in the developing nervous system rely on intracellular membrane dynamics that involve endosome maturation and transport, as well as its regulated tethering to the endoplasmic reticulum (ER). Recent studies have identified several key molecules, such as protrudin, which plays a dynamic role at membrane contact sites between the ER and endosomes/lysosomes, and myosin Va, which acts as a sensor for ER-derived Ca2+ that triggers peri-ER membrane export. These molecules form different types of multiprotein complexes at the interface of organelles and, in response to their surrounding microenvironments, such as Ca2+ concentrations and lipid contents, regulate the directional movement of endosomal vesicles in extending axons. Here, we review the molecular mechanisms underlying membrane dynamics and inter-organelle interactions during neuronal morphogenesis.
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7
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Fink JK. The hereditary spastic paraplegias. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:59-88. [PMID: 37620092 DOI: 10.1016/b978-0-323-98817-9.00022-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
The hereditary spastic paraplegias (HSPs) are a group of more than 90 genetic disorders in which lower extremity spasticity and weakness are either the primary neurologic impairments ("uncomplicated HSP") or when accompanied by other neurologic deficits ("complicated HSP"), important features of the clinical syndrome. Various genetic types of HSP are inherited such as autosomal dominant, autosomal recessive, X-linked, and maternal (mitochondrial) traits. Symptoms that begin in early childhood may be nonprogressive and resemble spastic diplegic cerebral palsy. Symptoms that begin later, typically progress insidiously over a number of years. Genetic testing is able to confirm the diagnosis for many subjects. Insights from gene discovery indicate that abnormalities in diverse molecular processes underlie various forms of HSP, including disturbance in axon transport, endoplasmic reticulum morphogenesis, vesicle transport, lipid metabolism, and mitochondrial function. Pathologic studies in "uncomplicated" HSP have shown axon degeneration particularly involving the distal ends of corticospinal tracts and dorsal column fibers. Treatment is limited to symptom reduction including amelioration of spasticity, reducing urinary urgency, proactive physical therapy including strengthening, stretching, balance, and agility exercise.
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Affiliation(s)
- John K Fink
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States.
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8
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Gim JA, Lee S, Kim SC, Baek KW, Yoo JI. Demographic and Genome Wide Association Analyses According to Muscle Mass Using Data of the Korean Genome and Epidemiology Study. J Korean Med Sci 2022; 37:e346. [PMID: 36573383 PMCID: PMC9792260 DOI: 10.3346/jkms.2022.37.e346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/26/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Sarcopenia is commonly found in the elderly due to a decline in muscle mass. Many researchers have performed genome-wide association studies (GWAS) to find genetic risk factors of sarcopenia. Although many studies have discovered sarcopenia associated single nucleotide polymorphisms (SNPs), most of them are studies targeting Caucasians. The purpose of this study was to evaluate genetic correlation according to muscle mass in middle aged Koreans using data of the Korean Genome and Epidemiology Study (KOGES), a large population-based genomic cohort study. METHODS Baseline participants were 10,030 subjects aged 40 to 69 years who were from Ansan or Anseong in Gyeonggi-do, South Korea. Among them, 9,351 subjects with laboratory data available were included in this study. To identify sarcopenia associated variants, those in the top 30% and bottom 30% of muscle mass index (MMI) were compared. A total of 7,452 people with an MMI of 30-70% were excluded. A total of 1,004 people were also excluded due to missing data. Finally, 895 people were selected for this study. The Korea Biobank Array generated 500,568 SNPs for this dataset. RESULTS When subjects were divided into top 30% and bottom 30% of MMI, the top 30% had 169 men and 308 women and the bottom 30% had 220 men and 198 women. In men, age, body mass index (BMI), waist and hip were significantly (P < 0.005) different between top 30% and bottom 30% MMI groups. In women, age, BMI, waist, hip, and hypertension history were significantly different between the two MMI groups. There were 13 significant SNPs in men and 14 significant SNPs in women. Genes associated with variants in men based on the single-nucleotide polymorphism database (dbSNP) were LRP1B containing rs11679458 and RGS6 containing rs11848300. A gene associated with variants in women was Pi4K2A, which contained rs1189312 as a variant. In addition, rs11189312 was associated with expression quantitative trait loci (eQTL) of ZFYVE27 in skeletal muscles and other SNPs of ZFYVE27 (rs10882883, rs17108378, rs35077384) known to be associated with spastic paraplegia. The eQTL analysis revealed that rs11189312 was a variant associated with SNPs of ZFYVE27. CONCLUSIONS In the demographic study, significant results were found in BMI, waist, hip, history of hyperlipidemia, and sedentary life status in male group, and significant results were found in BMI, waist, hip, and hypertension history in female group. Variant rs11189312 was found to be a novel variant affecting ZFYVE27 expressed in skeletal muscles, suggesting that rs11189312 might be related to sarcopenia as a novel discovery of this study. Further study is needed to determine the association between sarcopenia and ZFYVE27 known to be associated with spastic paraplegia.
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Affiliation(s)
- Jeong-An Gim
- Medical Science Research Center, College of Medicine, Korea University, Seoul, Korea
| | - Sangyeob Lee
- Department of Biomedical Research Institute, Gyeongsang National University Hospital, Jinju, Korea
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Gyeongsang National University, Jinju, Korea
| | - Seung Chan Kim
- Department of Biostatistics Cooperation Center, Gyeongsang National University Hospital, Jinju, Korea
| | - Kyung-Wan Baek
- Department of Physical Education, Gyeongsang National University, Jinju, Korea
- Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju, Korea
| | - Jun-Il Yoo
- Department of Orthopaedic Surgery, Gyeongsang National University Hospital, Jinju, Korea.
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Suhda S, Yamamoto Y, Wisesa S, Sada R, Sakisaka T. The 14-3-3γ isoform binds to and regulates the localization of endoplasmic reticulum (ER) membrane protein TMCC3 for the reticular network of the ER. J Biol Chem 2022; 299:102813. [PMID: 36549645 PMCID: PMC9860497 DOI: 10.1016/j.jbc.2022.102813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
The reticular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions and undergoes constant remodeling through formation and loss of the three-way junctions. Transmembrane and coiled-coil domain family 3 (TMCC3), an ER membrane protein localizing at three-way junctions, has been shown to positively regulate formation of the reticular ER network. However, elements that negatively regulate TMCC3 localization have not been characterized. In this study, we report that 14-3-3γ, a phospho-serine/phospho-threonine-binding protein involved in various signal transduction pathways, is a negative regulator of TMCC3. We demonstrate that overexpression of 14-3-3γ reduced localization of TMCC3 to three-way junctions and decreased the number of three-way junctions. TMCC3 bound to 14-3-3γ through the N terminus and had deduced 14-3-3 binding motifs. Additionally, we determined that a TMCC3 mutant substituting alanine for serine to be phosphorylated in the binding motif reduced binding to 14-3-3γ. The TMCC3 mutant was more prone than wildtype TMCC3 to localize at three-way junctions in the cells overexpressing 14-3-3γ. Furthermore, the TMCC3 mutant rescued the ER sheet expansion caused by TMCC3 knockdown less than wild-type TMCC3. Taken together, these results indicate that 14-3-3γ binding negatively regulates localization of TMCC3 to the three-way junctions for the proper reticular ER network, implying that the negative regulation of TMCC3 by 14-3-3γ would underlie remodeling of the reticular network of the ER.
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Affiliation(s)
- Saihas Suhda
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
| | - Yasunori Yamamoto
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
| | - Sindhu Wisesa
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
| | - Risa Sada
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
| | - Toshiaki Sakisaka
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan.
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10
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Al-Amri AH, Armstrong P, Amici M, Ligneul C, Rouse J, El-Asrag ME, Pantiru A, Vancollie VE, Ng HW, Ogbeta JA, Goodchild K, Ellegood J, Lelliott CJ, Mullins JG, Bretman A, Al-Ali R, Beetz C, Al-Gazali L, Al Shamsi A, Lerch JP, Mellor JR, Al Sayegh A, Ali M, Inglehearn CF, Clapcote SJ. PDZD8 Disruption Causes Cognitive Impairment in Humans, Mice, and Fruit Flies. Biol Psychiatry 2022; 92:323-334. [PMID: 35227461 PMCID: PMC9302898 DOI: 10.1016/j.biopsych.2021.12.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND The discovery of coding variants in genes that confer risk of intellectual disability (ID) is an important step toward understanding the pathophysiology of this common developmental disability. METHODS Homozygosity mapping, whole-exome sequencing, and cosegregation analyses were used to identify gene variants responsible for syndromic ID with autistic features in two independent consanguineous families from the Arabian Peninsula. For in vivo functional studies of the implicated gene's function in cognition, Drosophila melanogaster and mice with targeted interference of the orthologous gene were used. Behavioral, electrophysiological, and structural magnetic resonance imaging analyses were conducted for phenotypic testing. RESULTS Homozygous premature termination codons in PDZD8, encoding an endoplasmic reticulum-anchored lipid transfer protein, showed cosegregation with syndromic ID in both families. Drosophila melanogaster with knockdown of the PDZD8 ortholog exhibited impaired long-term courtship-based memory. Mice homozygous for a premature termination codon in Pdzd8 exhibited brain structural, hippocampal spatial memory, and synaptic plasticity deficits. CONCLUSIONS These data demonstrate the involvement of homozygous loss-of-function mutations in PDZD8 in a neurodevelopmental cognitive disorder. Model organisms with manipulation of the orthologous gene replicate aspects of the human phenotype and suggest plausible pathophysiological mechanisms centered on disrupted brain development and synaptic function. These findings are thus consistent with accruing evidence that synaptic defects are a common denominator of ID and other neurodevelopmental conditions.
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Affiliation(s)
- Ahmed H. Al-Amri
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom,Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom,National Genetic Centre, Royal Hospital, Muscat, Oman
| | - Paul Armstrong
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Mascia Amici
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Clemence Ligneul
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom
| | - James Rouse
- School of Biology, University of Leeds, Leeds, United Kingdom
| | - Mohammed E. El-Asrag
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom,Department of Zoology, Faculty of Science, Benha University, Benha, Egypt,Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham
| | - Andreea Pantiru
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | | | - Hannah W.Y. Ng
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Jennifer A. Ogbeta
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Kirstie Goodchild
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | - Amanda Bretman
- School of Biology, University of Leeds, Leeds, United Kingdom
| | | | | | - Lihadh Al-Gazali
- Department of Paediatrics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Aisha Al Shamsi
- Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates
| | - Jason P. Lerch
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom
| | - Jack R. Mellor
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Abeer Al Sayegh
- Genetics Department, Sultan Qaboos University Hospital, Muscat, Oman
| | - Manir Ali
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Chris F. Inglehearn
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Steven J. Clapcote
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom,Address correspondence to Steven J. Clapcote, Ph.D.
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11
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Panza E, Meyyazhagan A, Orlacchio A. Hereditary spastic paraplegia: Genetic heterogeneity and common pathways. Exp Neurol 2022; 357:114203. [PMID: 35970204 DOI: 10.1016/j.expneurol.2022.114203] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/11/2022] [Accepted: 08/09/2022] [Indexed: 02/07/2023]
Abstract
Hereditary Spastic Paraplegias (HSPs) are a heterogeneous group of disease, mainly characterized by progressive spasticity and weakness of the lower limbs resulting from distal degeneration of corticospinal tract axons. Although HSPs represent rare or ultra-rare conditions, with reported cases of mutated genes found in single families, overall, with 87 forms described, they are an important health and economic problem for society and patients. In fact, they are chronic and life-hindering conditions, still lacking a specific therapy. Notwithstanding the number of forms described, and 73 causative genes identified, overall, the molecular diagnostic rate varies among 29% to 61.8%, based on recent published analysis, suggesting that more genes are involved in HSP and/or that different molecular diagnostic approaches are necessary. The accumulating data in this field highlight several peculiar features of HSPs, such as genetic heterogeneity, the discovery that different mutations in a single gene can be transmitted in dominant and recessive trait in families and allelic heterogeneity, resulting in the involvement of HSP-genes in other conditions. Based on the observation of protein functions, the activity of many different proteins encoded by HSP-related genes converges into some distinct pathophysiological mechanisms. This suggests that common pathways could be a potential target for a therapy, possibly addressing several forms at once. Furthermore, the overlap of HSP genes with other neurological conditions can further expand this concept.
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Affiliation(s)
- Emanuele Panza
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
| | - Arun Meyyazhagan
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
| | - Antonio Orlacchio
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy; Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy.
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12
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Ubap1 knock-in mice reproduced the phenotype of SPG80. J Hum Genet 2022; 67:679-686. [PMID: 35962060 DOI: 10.1038/s10038-022-01073-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 07/03/2022] [Accepted: 07/28/2022] [Indexed: 11/08/2022]
Abstract
SPG80 is a neurodegenerative disorder characterized by a pure type of juvenile-onset hereditary spastic paraplegia and is caused by a heterozygous mutation of the UBAP1 (ubiquitin-associated protein 1) gene. UBAP1 is one of the subunits of the endosomal sorting complex required for transport I and plays a role in endosome sorting by binding to ubiquitin-tagged proteins. In this study, we generated novel Ubap1+/E176Efx23 knock-in mice, in which the SOUBA domain of Ubap1 was completely deleted with the UMA domain being intact, as an animal model of SPG80. The knock-in mice with this heterozygous Ubap1 truncated mutation appeared normal at birth, but they developed progressive hind limb dysfunction several months later. Molecular pathologically, loss of neurons in the spinal cord and accumulation of ubiquitinated proteins were observed in Ubap1+/E176Efx23 knock-in mice. In addition, changes in the distributions of Rab5 and Rab7 in the spinal cord suggest that this mutation in Ubap1 disturbs endosome-mediated vesicular trafficking. This is the first report of a mouse model that reproduces the phenotype of SPG80. Our knock-in mice may provide a clue for understanding the molecular pathogenesis underlying UBAP1-related HSP and screening of therapeutic agents.
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Kim S, Coukos R, Gao F, Krainc D. Dysregulation of organelle membrane contact sites in neurological diseases. Neuron 2022; 110:2386-2408. [PMID: 35561676 PMCID: PMC9357093 DOI: 10.1016/j.neuron.2022.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/21/2022] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
Abstract
The defining evolutionary feature of eukaryotic cells is the emergence of membrane-bound organelles. Compartmentalization allows each organelle to maintain a spatially, physically, and chemically distinct environment, which greatly bolsters individual organelle function. However, the activities of each organelle must be balanced and are interdependent for cellular homeostasis. Therefore, properly regulated interactions between organelles, either physically or functionally, remain critical for overall cellular health and behavior. In particular, neuronal homeostasis depends heavily on the proper regulation of organelle function and cross talk, and deficits in these functions are frequently associated with diseases. In this review, we examine the emerging role of organelle contacts in neurological diseases and discuss how the disruption of contacts contributes to disease pathogenesis. Understanding the molecular mechanisms underlying the formation and regulation of organelle contacts will broaden our knowledge of their role in health and disease, laying the groundwork for the development of new therapies targeting interorganelle cross talk and function.
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Affiliation(s)
- Soojin Kim
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Robert Coukos
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Fanding Gao
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL 60611, USA.
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14
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Selçuk E, Kırımtay K, Temizci B, Akarsu Ş, Everest E, Baslo MB, Demirkıran M, Yapıcı Z, Karabay A. MYO1H is a novel candidate gene for autosomal dominant pure hereditary spastic paraplegia. Mol Genet Genomics 2022; 297:1141-1150. [PMID: 35704118 DOI: 10.1007/s00438-022-01910-5] [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: 01/20/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022]
Abstract
In this study, we aimed to determine the genetic basis of a Turkish family related to hereditary spastic paraplegia (HSP) by exome sequencing. HSP is a progressive neurodegenerative disorder and displays genetic and clinical heterogeneity. The major symptoms are muscle weakness and spasticity, especially in the lower extremities. We studied seven affected and seven unaffected family members, as well as a clinically undetermined member, to identify the disease-causing gene. Exome sequencing was performed for four affected and two unaffected individuals. The variants were firstly filtered for HSP-associated genes, and we found a common variant in the ZFYVE27 gene, which has been previously implied for association with HSP. Due to the incompletely penetrant segregation pattern of the ZFYVE27 variant, revealed by Sanger sequencing, with the disease in this family, filtering was re-performed according to the mode of inheritance and allelic frequencies. The resulting 14 rare variants were further evaluated in terms of their cellular functions, and three candidate variants in ATAD3C, VPS16, and MYO1H genes were selected as possible causative variants, which were analyzed for their familial segregation. ATAD3C and VPS16 variants were eliminated due to incomplete penetrance. Eventually, the MYO1H variant NM_001101421.3:c.2972_2974del (p.Glu992del, rs372231088) was found as the possible disease-causing deletion for HSP in this family. This is the first study reporting the possible role of a MYO1H variant in HSP pathogenesis. Further studies on the cellular roles of Myo1h protein are needed to validate the causality of MYO1H gene at the onset of HSP.
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Affiliation(s)
- Ece Selçuk
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey
- Department of Molecular Biology and Genetics, Istanbul Medeniyet University, Istanbul, 34700, Turkey
| | - Koray Kırımtay
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey
| | - Benan Temizci
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul, 34469, Turkey
| | - Şeyma Akarsu
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul, 34469, Turkey
| | - Elif Everest
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul, 34469, Turkey
| | - Mehmet Barış Baslo
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - Meltem Demirkıran
- Department of Neurology, Faculty of Medicine, Çukurova University, 01330, Adana, Turkey
| | - Zuhal Yapıcı
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - Arzu Karabay
- Molecular Biology, Genetics-Biotechnology, Graduate School of Science, Engineering and Technology, Istanbul Technical University, 34469, Istanbul, Turkey.
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul, 34469, Turkey.
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15
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Hereditary Spastic Paraplegia: An Update. Int J Mol Sci 2022; 23:ijms23031697. [PMID: 35163618 PMCID: PMC8835766 DOI: 10.3390/ijms23031697] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/21/2021] [Accepted: 01/28/2022] [Indexed: 12/12/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) is a rare neurodegenerative disorder with the predominant clinical manifestation of spasticity in the lower extremities. HSP is categorised based on inheritance, the phenotypic characters, and the mode of molecular pathophysiology, with frequent degeneration in the axon of cervical and thoracic spinal cord’s lateral region, comprising the corticospinal routes. The prevalence ranges from 0.1 to 9.6 subjects per 100,000 reported around the globe. Though modern medical interventions help recognize and manage the disorder, the symptomatic measures remain below satisfaction. The present review assimilates the available data on HSP and lists down the chromosomes involved in its pathophysiology and the mutations observed in the respective genes on the chromosomes. It also sheds light on the treatment available along with the oral/intrathecal medications, physical therapies, and surgical interventions. Finally, we have discussed the related diagnostic techniques as well as the linked pharmacogenomics studies under future perspectives.
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16
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Elsayed LEO, Eltazi IZ, Ahmed AE, Stevanin G. Insights into Clinical, Genetic, and Pathological Aspects of Hereditary Spastic Paraplegias: A Comprehensive Overview. Front Mol Biosci 2021; 8:690899. [PMID: 34901147 PMCID: PMC8662366 DOI: 10.3389/fmolb.2021.690899] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 10/19/2021] [Indexed: 12/31/2022] Open
Abstract
Hereditary spastic paraplegias (HSP) are a heterogeneous group of motor neurodegenerative disorders that have the core clinical presentation of pyramidal syndrome which starts typically in the lower limbs. They can present as pure or complex forms with all classical modes of monogenic inheritance reported. To date, there are more than 100 loci/88 spastic paraplegia genes (SPG) involved in the pathogenesis of HSP. New patterns of inheritance are being increasingly identified in this era of huge advances in genetic and functional studies. A wide range of clinical symptoms and signs are now reported to complicate HSP with increasing overall complexity of the clinical presentations considered as HSP. This is especially true with the emergence of multiple HSP phenotypes that are situated in the borderline zone with other neurogenetic disorders. The genetic diagnostic approaches and the utilized techniques leave a diagnostic gap of 25% in the best studies. In this review, we summarize the known types of HSP with special focus on those in which spasticity is the principal clinical phenotype ("SPGn" designation). We discuss their modes of inheritance, clinical phenotypes, underlying genetics, and molecular pathways, providing some observations about therapeutic opportunities gained from animal models and functional studies. This review may pave the way for more analytic approaches that take into consideration the overall picture of HSP. It will shed light on subtle associations that can explain the occurrence of the disease and allow a better understanding of its observed variations. This should help in the identification of future biomarkers, predictors of disease onset and progression, and treatments for both better functional outcomes and quality of life.
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Affiliation(s)
- Liena E. O. Elsayed
- Department of Basic Sciences, College of Medicine, Princess Nourah bint Abdulrahman University [PNU], Riyadh, Saudi Arabia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Ammar E. Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Giovanni Stevanin
- Institut du Cerveau – Paris Brain Institute - ICM, Sorbonne Université, INSERM, CNRS, APHP, Paris, France
- CNRS, INCIA, Université de Bordeaux, Bordeaux, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
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17
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ER Morphology in the Pathogenesis of Hereditary Spastic Paraplegia. Cells 2021; 10:cells10112870. [PMID: 34831093 PMCID: PMC8616106 DOI: 10.3390/cells10112870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 12/18/2022] Open
Abstract
The endoplasmic reticulum (ER) is the most abundant and widespread organelle in cells. Its peculiar membrane architecture, formed by an intricate network of tubules and cisternae, is critical to its multifaceted function. Regulation of ER morphology is coordinated by a few ER-specific membrane proteins and is thought to be particularly important in neurons, where organized ER membranes are found even in the most distant neurite terminals. Mutation of ER-shaping proteins has been implicated in the neurodegenerative disease hereditary spastic paraplegia (HSP). In this review we discuss the involvement of these proteins in the pathogenesis of HSP, focusing on the experimental evidence linking their molecular function to disease onset. Although the precise biochemical activity of some ER-related HSP proteins has been elucidated, the pathological mechanism underlying ER-linked HSP is still undetermined and needs to be further investigated.
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18
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Intertwined and Finely Balanced: Endoplasmic Reticulum Morphology, Dynamics, Function, and Diseases. Cells 2021; 10:cells10092341. [PMID: 34571990 PMCID: PMC8472773 DOI: 10.3390/cells10092341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.
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19
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Tadepalle N, Rugarli EI. Lipid Droplets in the Pathogenesis of Hereditary Spastic Paraplegia. Front Mol Biosci 2021; 8:673977. [PMID: 34041268 PMCID: PMC8141572 DOI: 10.3389/fmolb.2021.673977] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/26/2021] [Indexed: 12/21/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs) are genetically heterogeneous conditions caused by the progressive dying back of the longest axons in the central nervous system, the corticospinal axons. A wealth of data in the last decade has unraveled disturbances of lipid droplet (LD) biogenesis, maturation, turnover and contact sites in cellular and animal models with perturbed expression and function of HSP proteins. As ubiquitous organelles that segregate neutral lipid into a phospholipid monolayer, LDs are at the cross-road of several processes including lipid metabolism and trafficking, energy homeostasis, and stress signaling cascades. However, their role in brain cells, especially in neurons remains enigmatic. Here, we review experimental findings linking LD abnormalities to defective function of proteins encoded by HSP genes, and discuss arising questions in the context of the pathogenesis of HSP.
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Affiliation(s)
- Nimesha Tadepalle
- Molecular and Cell Biology Laboratory, Salk Institute of Biological Sciences, La Jolla, CA, United States
| | - Elena I Rugarli
- Institute for Genetics, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany.,Center for Molecular Medicine (CMMC),Cologne, Germany
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20
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Venditti R, Wilson C, De Matteis MA. Regulation and physiology of membrane contact sites. Curr Opin Cell Biol 2021; 71:148-157. [PMID: 33932623 DOI: 10.1016/j.ceb.2021.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/18/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Membrane contact sites (MCSs) in addition to impacting the functions of membrane-limited organelles also have a role in the spatial and functional organization of cells, tissues and whole organisms. MCSs have been identified between all organelles and the identification of their molecular composition has progressed significantly in recent years. Equally important is how MCSs respond dynamically to physiological stimuli, how this is regulated, and the physiological roles of MCSs in tissues and at the organismal level, an area that still remains relatively unexplored. In the present review, we focus on the regulation of MCSs, considerations of their function at the organismal level, and how mutations of MCS components linked to genetic diseases might inform us about their physiological relevance.
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Affiliation(s)
- Rossella Venditti
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy
| | - Cathal Wilson
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy.
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21
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Abstract
Our cells are comprised of billions of proteins, lipids, and other small molecules packed into their respective subcellular organelles, with the daunting task of maintaining cellular homeostasis over a lifetime. However, it is becoming increasingly evident that organelles do not act as autonomous discrete units but rather as interconnected hubs that engage in extensive communication through membrane contacts. In the last few years, our understanding of how these contacts coordinate organelle function has redefined our view of the cell. This review aims to present novel findings on the cellular interorganelle communication network and how its dysfunction may contribute to aging and neurodegeneration. The consequences of disturbed interorganellar communication are intimately linked with age-related pathologies. Given that both aging and neurodegenerative diseases are characterized by the concomitant failure of multiple cellular pathways, coordination of organelle communication and function could represent an emerging regulatory mechanism critical for long-term cellular homeostasis. We anticipate that defining the relationships between interorganelle communication, aging, and neurodegeneration will open new avenues for therapeutics.
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Affiliation(s)
- Maja Petkovic
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
| | - Caitlin E O'Brien
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
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22
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Axonal Organelles as Molecular Platforms for Axon Growth and Regeneration after Injury. Int J Mol Sci 2021; 22:ijms22041798. [PMID: 33670312 PMCID: PMC7918155 DOI: 10.3390/ijms22041798] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Investigating the molecular mechanisms governing developmental axon growth has been a useful approach for identifying new strategies for boosting axon regeneration after injury, with the goal of treating debilitating conditions such as spinal cord injury and vision loss. The picture emerging is that various axonal organelles are important centers for organizing the molecular mechanisms and machinery required for growth cone development and axon extension, and these have recently been targeted to stimulate robust regeneration in the injured adult central nervous system (CNS). This review summarizes recent literature highlighting a central role for organelles such as recycling endosomes, the endoplasmic reticulum, mitochondria, lysosomes, autophagosomes and the proteasome in developmental axon growth, and describes how these organelles can be targeted to promote axon regeneration after injury to the adult CNS. This review also examines the connections between these organelles in developing and regenerating axons, and finally discusses the molecular mechanisms within the axon that are required for successful axon growth.
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23
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Edmison D, Wang L, Gowrishankar S. Lysosome Function and Dysfunction in Hereditary Spastic Paraplegias. Brain Sci 2021; 11:152. [PMID: 33498913 PMCID: PMC7911997 DOI: 10.3390/brainsci11020152] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/15/2021] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
Hereditary Spastic Paraplegias (HSPs) are a genetically diverse group of inherited neurological diseases with over 80 associated gene loci. Over the last decade, research into mechanisms underlying HSPs has led to an emerging interest in lysosome dysfunction. In this review, we highlight the different classes of HSPs that have been linked to lysosome defects: (1) a subset of complex HSPs where mutations in lysosomal genes are causally linked to the diseases, (2) other complex HSPs where mutation in genes encoding membrane trafficking adaptors lead to lysosomal defects, and (3) a subset of HSPs where mutations affect genes encoding proteins whose function is primarily linked to a different cellular component or organelle such as microtubule severing and Endoplasmic Reticulum-shaping, while also altering to lysosomes. Interestingly, aberrant axonal lysosomes, associated with the latter two subsets of HSPs, are a key feature observed in other neurodegenerative diseases such as Alzheimer's disease. We discuss how altered lysosome function and trafficking may be a critical contributor to HSP pathology and highlight the need for examining these features in the cortico-spinal motor neurons of HSP mutant models.
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Affiliation(s)
| | | | - Swetha Gowrishankar
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (D.E.); (L.W.)
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24
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Shirane M. Lipid Transfer-Dependent Endosome Maturation Mediated by Protrudin and PDZD8 in Neurons. Front Cell Dev Biol 2020; 8:615600. [PMID: 33385000 PMCID: PMC7769939 DOI: 10.3389/fcell.2020.615600] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/23/2020] [Indexed: 12/16/2022] Open
Abstract
Endosome maturation refers to the conversion of early endosomes (EEs) to late endosomes (LEs) for subsequent fusion with lysosomes. It is an incremental process that involves a combination of endosome fusion and fission and which occurs at contact sites between endosomes and the endoplasmic reticulum (ER), with knowledge of the underlying mechanisms having increased greatly in recent years. Protrudin is an ER-resident protein that was originally shown to regulate neurite formation by promoting endosome trafficking, whereas PDZD8 is a mammalian paralog of a subunit of the yeast ERMES (ER-mitochondrial encounter structure) complex that possesses lipid transfer activity. A complex of protrudin and PDZD8 was recently found to promote endosome maturation by mediating lipid transfer at ER-endosome membrane contact sites. This review focuses on the roles of the protrudin-PDZD8 complex in tethering of endosomes to the ER, in mediating lipid transfer at such contact sites, and in regulating endosome dynamics, especially in neuronal cells. It also addresses the physiological contribution of endosome maturation mediated by this complex to neuronal polarity and integrity.
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Affiliation(s)
- Michiko Shirane
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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25
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Gunay A, Shin HH, Gozutok O, Gautam M, Ozdinler PH. Importance of lipids for upper motor neuron health and disease. Semin Cell Dev Biol 2020; 112:92-104. [PMID: 33323321 DOI: 10.1016/j.semcdb.2020.11.004] [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: 05/26/2020] [Revised: 10/12/2020] [Accepted: 11/11/2020] [Indexed: 12/18/2022]
Abstract
Building evidence reveals the importance of maintaining lipid homeostasis for the health and function of neurons, and upper motor neurons (UMNs) are no exception. UMNs are critically important for the initiation and modulation of voluntary movement as they are responsible for conveying cerebral cortex' input to spinal cord targets. To maintain their unique cytoarchitecture with a prominent apical dendrite and a very long axon, UMNs require a stable cell membrane, a lipid bilayer. Lipids can act as building blocks for many biomolecules, and they also contribute to the production of energy. Therefore, UMNs require sustained control over the production, utilization and homeostasis of lipids. Perturbations of lipid homeostasis lead to UMN vulnerability and progressive degeneration in diseases such as hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS). Here, we discuss the importance of lipids, especially for UMNs.
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Affiliation(s)
- Aksu Gunay
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA, 60611
| | - Heather H Shin
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA, 60611
| | - Oge Gozutok
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA, 60611
| | - Mukesh Gautam
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA, 60611
| | - P Hande Ozdinler
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA, 60611.
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26
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Shirane M, Shoji H, Hashimoto Y, Katagiri H, Kobayashi S, Manabe T, Miyakawa T, Nakayama KI. Protrudin-deficient mice manifest depression-like behavior with abnormalities in activity, attention, and cued fear-conditioning. Mol Brain 2020; 13:146. [PMID: 33172474 PMCID: PMC7654181 DOI: 10.1186/s13041-020-00693-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 11/03/2020] [Indexed: 01/02/2023] Open
Abstract
Protrudin is a protein that resides in the membrane of the endoplasmic reticulum and is highly expressed in the nervous system. Although mutations in the human protrudin gene (ZFYVE27, also known as SPG33) give rise to hereditary spastic paraplegia (HSP), the physiological role of the encoded protein has been largely unclear. We therefore generated mice deficient in protrudin and subjected them to a battery of behavioral tests designed to examine their intermediate phenotypes. The protrudin-deficient mice were found to have a reduced body size and to manifest pleiotropic behavioral abnormalities, including hyperactivity, depression-like behavior, and deficits in attention and fear-conditioning memory. They exhibited no signs of HSP, however, consistent with the notion that HSP-associated mutations of protrudin may elicit neural degeneration, not as a result of a loss of function, but rather as a result of a gain of toxic function. Overall, our results suggest that protrudin might play an indispensable role in normal neuronal development and behavior.
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Affiliation(s)
- Michiko Shirane
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan.
| | - Hirotaka Shoji
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Yutaka Hashimoto
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka, Japan
| | - Hiroyuki Katagiri
- Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Shizuka Kobayashi
- Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Toshiya Manabe
- Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka, Japan.
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27
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Protrudin and PDZD8 contribute to neuronal integrity by promoting lipid extraction required for endosome maturation. Nat Commun 2020; 11:4576. [PMID: 32917905 PMCID: PMC7486383 DOI: 10.1038/s41467-020-18413-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/21/2020] [Indexed: 01/08/2023] Open
Abstract
Endosome maturation depends on membrane contact sites (MCSs) formed between endoplasmic reticulum (ER) and endolysosomes (LyLEs). The mechanism underlying lipid supply for this process and its pathophysiological relevance remains unclear, however. Here, we identify PDZD8-the mammalian ortholog of a yeast ERMES subunit-as a protein that interacts with protrudin, which is located at ER-LyLE MCSs. Protrudin and PDZD8 promote the formation of ER-LyLE MCSs, and PDZD8 shows the ability to extract various lipids from the ER. Overexpression of both protrudin and PDZD8 in HeLa cells, as well as their depletion in mouse primary neurons, impairs endosomal homeostasis by inducing the formation of abnormal large vacuoles reminiscent of those apparent in spastin- or REEP1-deficient neurons. The protrudin-PDZD8 system is also essential for the establishment of neuronal polarity. Our results suggest that protrudin and PDZD8 cooperatively promote endosome maturation by mediating ER-LyLE tethering and lipid extraction at MCSs, thereby maintaining neuronal polarity and integrity.
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TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum. Biochem J 2020; 476:3241-3260. [PMID: 31696206 DOI: 10.1042/bcj20190359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/08/2019] [Accepted: 10/17/2019] [Indexed: 01/26/2023]
Abstract
The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.
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29
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Connell JW, Allison RJ, Rodger CE, Pearson G, Zlamalova E, Reid E. ESCRT-III-associated proteins and spastin inhibit protrudin-dependent polarised membrane traffic. Cell Mol Life Sci 2020; 77:2641-2658. [PMID: 31587092 PMCID: PMC7320071 DOI: 10.1007/s00018-019-03313-z] [Citation(s) in RCA: 21] [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: 03/27/2019] [Revised: 08/27/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022]
Abstract
Mutations in the gene encoding the microtubule severing ATPase spastin are the most frequent cause of hereditary spastic paraplegia, a genetic condition characterised by length-dependent axonal degeneration. Here, we show that HeLa cells lacking spastin and embryonic fibroblasts from a spastin knock-in mouse model become highly polarised and develop cellular protrusions. In HeLa cells, this phenotype was rescued by wild-type spastin, but not by forms unable to sever microtubules or interact with endosomal ESCRT-III proteins. Cells lacking the spastin-interacting ESCRT-III-associated proteins IST1 or CHMP1B also developed protrusions. The protrusion phenotype required protrudin, a RAB-interacting protein that interacts with spastin and localises to ER-endosome contact sites, where it promotes KIF5-dependent endosomal motility to protrusions. Consistent with this, the protrusion phenotype in cells lacking spastin also required KIF5. Lack or mutation of spastin resulted in functional consequences for receptor traffic of a pathway implicated in HSP, as Bone Morphogenetic Protein receptor distribution became polarised. Our results, therefore, identify a novel role for ESCRT-III proteins and spastin in regulating polarised membrane traffic.
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Affiliation(s)
- James W Connell
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK
- Alzheimer's Research, Cambridge, UK
| | - Rachel J Allison
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Catherine E Rodger
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Guy Pearson
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Eliska Zlamalova
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Evan Reid
- Department of Medical Genetics and Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0XY, UK.
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30
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Tu Y, Zhao L, Billadeau DD, Jia D. Endosome-to-TGN Trafficking: Organelle-Vesicle and Organelle-Organelle Interactions. Front Cell Dev Biol 2020; 8:163. [PMID: 32258039 PMCID: PMC7093645 DOI: 10.3389/fcell.2020.00163] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022] Open
Abstract
Retrograde transport from endosomes to the trans-Golgi network (TGN) diverts proteins and lipids away from lysosomal degradation. It is essential for maintaining cellular homeostasis and signaling. In recent years, significant advancements have been made in understanding this classical pathway, revealing new insights into multiple steps of vesicular trafficking as well as critical roles of ER-endosome contacts for endosomal trafficking. In this review, we summarize up-to-date knowledge about this trafficking pathway, in particular, mechanisms of cargo recognition at endosomes and vesicle tethering at the TGN, and contributions of ER-endosome contacts.
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Affiliation(s)
- Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, State Key Laboratory of Biotherapy, Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Lin Zhao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, State Key Laboratory of Biotherapy, Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Daniel D. Billadeau
- Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN, United States
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, State Key Laboratory of Biotherapy, Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
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Protrudin modulates seizure activity through GABA A receptor regulation. Cell Death Dis 2019; 10:897. [PMID: 31772151 PMCID: PMC6879747 DOI: 10.1038/s41419-019-2118-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/13/2019] [Accepted: 10/31/2019] [Indexed: 11/30/2022]
Abstract
Epilepsy is a serious neurological disease characterized by recurrent unprovoked seizures. The exact etiology of epilepsy is not fully understood. Protrudin is a neural membrane protein and is found to be mutated in hereditary spastic paraplegia that characterized by symptoms like seizures. Here, we reported that the expression of protrudin was downregulated in the temporal neocortex of epileptic patients and in the hippocampus and cortex of pentylenetetrazol and kainic acid-kindled epileptic mouse models. Behavioral and electroencephalogram analyses indicated that overexpression of protrudin in the mouse hippocampus increased the latency of the seizure and decreased the frequency and duration of seizure activity. Using whole-cell patch clamp, overexpression of protrudin in the mouse hippocampus resulted in a reduction in action potential frequency and an increase in gamma-aminobutyric acid (GABA)ergic inhibitory current amplitude. Moreover, western blot analysis showed that the membrane expression of the GABA A receptor β2/3 subunit was also upregulated after protrudin overexpression, and coimmunoprecipitation resulted in a protein–protein interaction between protrudin, GABAARβ2/3 and GABA receptor-associated protein in the hippocampus of epileptic mice. These findings suggest that protrudin probably inhibits the occurrence and development of epilepsy through the regulation of GABAA receptor-mediated synaptic transmission, and protrudin might be a promising target for the treatment of epilepsy.
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Fowler PC, Garcia-Pardo ME, Simpson JC, O'Sullivan NC. NeurodegenERation: The Central Role for ER Contacts in Neuronal Function and Axonopathy, Lessons From Hereditary Spastic Paraplegias and Related Diseases. Front Neurosci 2019; 13:1051. [PMID: 31680803 PMCID: PMC6801308 DOI: 10.3389/fnins.2019.01051] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022] Open
Abstract
The hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative conditions whose characteristic feature is degeneration of the longest axons within the corticospinal tract which leads to progressive spasticity and weakness of the lower limbs. Though highly genetically heterogeneous, the majority of HSP cases are caused by mutations in genes encoding proteins that are responsible for generating and organizing the tubular endoplasmic reticulum (ER). Despite this, the role of the ER within neurons, particularly the long axons affected in HSP, is not well understood. Throughout axons, ER tubules make extensive contacts with other organelles, the cytoskeleton and the plasma membrane. At these ER contacts, protein complexes work in concert to perform specialized functions including organelle shaping, calcium homeostasis and lipid biogenesis, all of which are vital for neuronal survival and may be disrupted by HSP-causing mutations. In this article we summarize the proteins which mediate ER contacts, review the functions these contacts are known to carry out within neurons, and discuss the potential contribution of disruption of ER contacts to axonopathy in HSP.
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Affiliation(s)
- Philippa C Fowler
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - M Elena Garcia-Pardo
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Jeremy C Simpson
- UCD School of Biology and Environmental Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
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33
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Guo W, Stoklund Dittlau K, Van Den Bosch L. Axonal transport defects and neurodegeneration: Molecular mechanisms and therapeutic implications. Semin Cell Dev Biol 2019; 99:133-150. [PMID: 31542222 DOI: 10.1016/j.semcdb.2019.07.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 06/22/2019] [Accepted: 07/09/2019] [Indexed: 12/12/2022]
Abstract
Because of the extremely polarized morphology, the proper functioning of neurons largely relies on the efficient cargo transport along the axon. Axonal transport defects have been reported in multiple neurodegenerative diseases as an early pathological feature. The discovery of mutations in human genes involved in the transport machinery provide a direct causative relationship between axonal transport defects and neurodegeneration. Here, we summarize the current genetic findings related to axonal transport in neurodegenerative diseases, and we discuss the relationship between axonal transport defects and other pathological changes observed in neurodegeneration. In addition, we summarize the therapeutic approaches targeting the axonal transport machinery in studies of neurodegenerative diseases. Finally, we review the technical advances in tracking axonal transport both in vivo and in vitro.
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Affiliation(s)
- Wenting Guo
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium; KU Leuven-Stem Cell Institute (SCIL), Leuven, Belgium
| | - Katarina Stoklund Dittlau
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ludo Van Den Bosch
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
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34
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Volpatti JR, Al-Maawali A, Smith L, Al-Hashim A, Brill JA, Dowling JJ. The expanding spectrum of neurological disorders of phosphoinositide metabolism. Dis Model Mech 2019; 12:12/8/dmm038174. [PMID: 31413155 PMCID: PMC6737944 DOI: 10.1242/dmm.038174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Phosphoinositides (PIPs) are a ubiquitous group of seven low-abundance phospholipids that play a crucial role in defining localized membrane properties and that regulate myriad cellular processes, including cytoskeletal remodeling, cell signaling cascades, ion channel activity and membrane traffic. PIP homeostasis is tightly regulated by numerous inositol kinases and phosphatases, which phosphorylate and dephosphorylate distinct PIP species. The importance of these phospholipids, and of the enzymes that regulate them, is increasingly being recognized, with the identification of human neurological disorders that are caused by mutations in PIP-modulating enzymes. Genetic disorders of PIP metabolism include forms of epilepsy, neurodegenerative disease, brain malformation syndromes, peripheral neuropathy and congenital myopathy. In this Review, we provide an overview of PIP function and regulation, delineate the disorders associated with mutations in genes that modulate or utilize PIPs, and discuss what is understood about gene function and disease pathogenesis as established through animal models of these diseases. Summary: This Review highlights the intersection between phosphoinositides and the enzymes that regulate their metabolism, which together are crucial regulators of myriad cellular processes and neurological disorders.
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Affiliation(s)
- Jonathan R Volpatti
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Almundher Al-Maawali
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
| | - Lindsay Smith
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Aqeela Al-Hashim
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Neuroscience, King Fahad Medical City, Riyadh 11525, Saudi Arabia
| | - Julie A Brill
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - James J Dowling
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada .,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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35
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Complexity of Generating Mouse Models to Study the Upper Motor Neurons: Let Us Shift Focus from Mice to Neurons. Int J Mol Sci 2019; 20:ijms20163848. [PMID: 31394733 PMCID: PMC6720674 DOI: 10.3390/ijms20163848] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Motor neuron circuitry is one of the most elaborate circuitries in our body, which ensures voluntary and skilled movement that requires cognitive input. Therefore, both the cortex and the spinal cord are involved. The cortex has special importance for motor neuron diseases, in which initiation and modulation of voluntary movement is affected. Amyotrophic lateral sclerosis (ALS) is defined by the progressive degeneration of both the upper and lower motor neurons, whereas hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS) are characterized mainly by the loss of upper motor neurons. In an effort to reveal the cellular and molecular basis of neuronal degeneration, numerous model systems are generated, and mouse models are no exception. However, there are many different levels of complexities that need to be considered when developing mouse models. Here, we focus our attention to the upper motor neurons, which are one of the most challenging neuron populations to study. Since mice and human differ greatly at a species level, but the cells/neurons in mice and human share many common aspects of cell biology, we offer a solution by focusing our attention to the affected neurons to reveal the complexities of diseases at a cellular level and to improve translational efforts.
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36
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SHIRANE M. Roles of protrudin at interorganelle membrane contact sites. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2019; 95:312-320. [PMID: 31406056 PMCID: PMC6766452 DOI: 10.2183/pjab.95.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 04/08/2019] [Indexed: 06/10/2023]
Abstract
Intracellular organelles were long viewed as isolated compartments floating in the cytosol. However, this view has been radically changed within the last decade by the discovery that most organelles communicate with the endoplasmic reticulum (ER) network via membrane contact sites (MCSs) that are essential for intracellular homeostasis. Protrudin is an ER resident protein that was originally shown to regulate neurite formation by promoting endosome trafficking. More recently, however, protrudin has been found to serve as a tethering factor at MCSs. The roles performed by protrudin at MCSs are mediated by its various domains, including inactivation of the small GTPase Rab11, bending of the ER membrane, and functional interactions with other molecules such as the motor protein KIF5 and the ER protein VAP. Mutations in the protrudin gene (ZFYVE27) are associated with hereditary spastic paraplegia, an axonopathy that results from defective ER structure. This review, examines the pleiotropic molecular functions of protrudin and its role in interorganellar communication.
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Affiliation(s)
- Michiko SHIRANE
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan
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37
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Vevera J, Zarrei M, Hartmannová H, Jedličková I, Mušálková D, Přistoupilová A, Oliveriusová P, Trešlová H, Nosková L, Hodaňová K, Stránecký V, Jiřička V, Preiss M, Příhodová K, Šaligová J, Wei J, Woodbury-Smith M, Bleyer AJ, Scherer SW, Kmoch S. Rare copy number variation in extremely impulsively violent males. GENES BRAIN AND BEHAVIOR 2018; 18:e12536. [DOI: 10.1111/gbb.12536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Jan Vevera
- Department of Psychiatry; Faculty of Medicine and University Hospital in Pilsen, Charles University; Prague Czech Republic
- Department of Psychiatry, First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
- Institute for Postgraduate Medical Education; Prague Czech Republic
- Psychology Department; National Institute of Mental Health; Klecany Czech Republic
| | - Mehdi Zarrei
- The Centre for Applied Genomics and Program in Genetics and Genome Biology; The Hospital for Sick Children; Toronto Ontario Canada
| | - Hana Hartmannová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Ivana Jedličková
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Dita Mušálková
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Anna Přistoupilová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Petra Oliveriusová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Helena Trešlová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Lenka Nosková
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Kateřina Hodaňová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Viktor Stránecký
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
| | - Václav Jiřička
- Prison Service of the Czech Republic, Directorate General; Department of Psychology; Prague Czech Republic
| | - Marek Preiss
- Psychology Department; National Institute of Mental Health; Klecany Czech Republic
- Psychology Department; University of New York in Prague; Prague Czech Republic
| | - Kateřina Příhodová
- Psychology Department; National Institute of Mental Health; Klecany Czech Republic
| | - Jana Šaligová
- Children's Faculty Hospital; Department of Pediatrics and Adolescent Medicine; Kosice Slovakia
- Department of Pediatrics and Adolescent Medicine, Faculty of Medicine of Pavel Jozef Šafárik University Kosice; Kosice Slovakia
| | - John Wei
- The Centre for Applied Genomics and Program in Genetics and Genome Biology; The Hospital for Sick Children; Toronto Ontario Canada
| | - Marc Woodbury-Smith
- The Centre for Applied Genomics and Program in Genetics and Genome Biology; The Hospital for Sick Children; Toronto Ontario Canada
- Institute of Neuroscience, Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary; Newcastle upon Tyne UK
| | - Anthony J. Bleyer
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
- Section on Nephrology, Wake Forest School of Medicine; Medical Center Blvd.; Winston-Salem North Carolina USA
| | - Stephen W. Scherer
- The Centre for Applied Genomics and Program in Genetics and Genome Biology; The Hospital for Sick Children; Toronto Ontario Canada
- Department of Molecular Genetics and McLaughlin Centre; University of Toronto; Toronto Ontario Canada
| | - Stanislav Kmoch
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine; First Faculty of Medicine, Charles University; Prague Czech Republic
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Abstract
Our textbook image of organelles has changed. Instead of revealing isolated cellular compartments, the picture now emerging shows organelles as largely interdependent structures that can communicate through membrane contact sites (MCSs). MCSs are sites where opposing organelles are tethered but do not fuse. MCSs provide a hybrid location where the tool kits of two different organelles can work together to perform vital cellular functions, such as lipid and ion transfer, signaling, and organelle division. Here, we focus on MCSs involving the endoplasmic reticulum (ER), an organelle forming an extensive network of cisternae and tubules. We highlight how the dynamic ER network regulates a plethora of cellular processes through MCSs with various organelles and with the plasma membrane.
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Affiliation(s)
- Haoxi Wu
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Pedro Carvalho
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK.
| | - Gia K Voeltz
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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Novel Type of Complicated Autosomal Dominant Hereditary Spastic Paraplegia Associated with Congenital Distal Arthrogryposis Type I. Brain Sci 2018; 8:brainsci8070136. [PMID: 30029526 PMCID: PMC6071261 DOI: 10.3390/brainsci8070136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/09/2018] [Accepted: 07/14/2018] [Indexed: 12/15/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) is one of the most genetically heterogeneous neurological disorders. HSP is classified as pure when only a spastic weakness of the lower extremities is present. Complex HSP comes with additional neurological or systemic abnormalities. Complex HSP with skeletal abnormalities is rare and mostly seen in autosomal recessive HSP. Autosomal dominant (AD) complex HSP with skeletal abnormalities are consistently seen only in SPG9 (spastic gait type 9). In this paper, we report a kindred condition with AD HSP among four living affected individuals who had progressive, adult onset spastic paraparesis that was associated with a distal arthrogryposis (DA) in every affected individual. They also had episodes of rhabdomyolysis without any clinical signs of myopathy. Exhaustive genetic analysis including targeted sequencing of known HSP and DA genes and whole exome sequencing did not identify the disease-causing gene. It excluded all known HSP and DA genes. We propose that this is a novel genetic type of complex AD HSP. Elucidation of a genetic cause of this type of HSP will further contribute to our understanding of axonal degeneration and skeletal abnormalities.
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Abstract
Hereditary spastic paraplegia comprises a wide and heterogeneous group of inherited neurodegenerative and neurodevelopmental disorders resulting from primary retrograde dysfunction of the long descending fibers of the corticospinal tract. Although spastic paraparesis and urinary dysfunction represent the most common clinical presentation, a complex group of different neurological and systemic compromise has been recognized recently and a growing number of new genetic subtypes were described in the last decade. Clinical characterization of individual and familial history represents the main step during diagnostic workup; however, frequently, few and unspecific data allows a low rate of definite diagnosis based solely in clinical and neuroimaging basis. Likewise, a wide group of neurological acquired and inherited disorders should be included in the differential diagnosis and properly excluded after a complete laboratorial, neuroimaging, and genetic evaluation. The aim of this review article is to provide an extensive overview regarding the main clinical and genetic features of the classical and recently described subtypes of hereditary spastic paraplegia (HSP).
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41
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Fatty acid synthase cooperates with protrudin to facilitate membrane outgrowth of cellular protrusions. Sci Rep 2017; 7:46569. [PMID: 28429738 PMCID: PMC5399442 DOI: 10.1038/srep46569] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/17/2017] [Indexed: 01/02/2023] Open
Abstract
Cellular protrusion formation capacity is a key feature of developing neurons and many eukaryotic cells. However, the mechanisms underlying membrane growth in protrusion formation are largely unclear. In this study, photo-reactive unnatural amino acid 3-(3-methyl-3H-diazirin-3-yl)-propamino-carbonyl-Nε-l-lysine was incorporated by a genetic code expansion strategy into protrudin, a protein localized in acidic endosomes and in the endoplasmic reticulum, that induces cellular protrusion and neurite formation. The modified protrudin was used for covalent trapping of protrudin-interacting proteins in living cells. Fatty acid synthase (FASN), which synthesizes free fatty acids, was identified to transiently interact with protrudin. Further characterization revealed a unique cooperation mechanism in which protrudin cooperates with FASN to facilitate cellular protrusion formation. This work reveals a novel mechanism involved in protrusion formation that is dependent on transient interaction between FASN and protrudin, and establishes a creative strategy to investigate transient protein-protein interactions in mammalian cells.
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Allison R, Edgar JR, Pearson G, Rizo T, Newton T, Günther S, Berner F, Hague J, Connell JW, Winkler J, Lippincott-Schwartz J, Beetz C, Winner B, Reid E. Defects in ER-endosome contacts impact lysosome function in hereditary spastic paraplegia. J Cell Biol 2017; 216:1337-1355. [PMID: 28389476 PMCID: PMC5412567 DOI: 10.1083/jcb.201609033] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 01/20/2017] [Accepted: 02/21/2017] [Indexed: 01/29/2023] Open
Abstract
Hereditary spastic paraplegia (HSP) is a genetically heterogeneous disease caused by mutations in many genes, including those encoding spastin, strumpellin, or REEP1. Allison et al. show that similar lysosomal phenotypes are associated with mutations in different classes of HSP proteins and suggest that defective ER–endosome contacts and endosome tubule fission may be a common cause of axon degeneration in the disease. Contacts between endosomes and the endoplasmic reticulum (ER) promote endosomal tubule fission, but the mechanisms involved and consequences of tubule fission failure are incompletely understood. We found that interaction between the microtubule-severing enzyme spastin and the ESCRT protein IST1 at ER–endosome contacts drives endosomal tubule fission. Failure of fission caused defective sorting of mannose 6-phosphate receptor, with consequently disrupted lysosomal enzyme trafficking and abnormal lysosomal morphology, including in mouse primary neurons and human stem cell–derived neurons. Consistent with a role for ER-mediated endosomal tubule fission in lysosome function, similar lysosomal abnormalities were seen in cellular models lacking the WASH complex component strumpellin or the ER morphogen REEP1. Mutations in spastin, strumpellin, or REEP1 cause hereditary spastic paraplegia (HSP), a disease characterized by axonal degeneration. Our results implicate failure of the ER–endosome contact process in axonopathy and suggest that coupling of ER-mediated endosomal tubule fission to lysosome function links different classes of HSP proteins, previously considered functionally distinct, into a unifying pathway for axonal degeneration.
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Affiliation(s)
- Rachel Allison
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - James R Edgar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Clinical Biochemistry, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - Guy Pearson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - Tania Rizo
- Interdisciplinary Center for Clinical Research (IZKF) Junior Research Group III and Federal Ministry of Education and Research (BMBF) Research Group Neuroscience, Friedrich-Alexander-University Erlangen-Nuernberg, 91054 Erlangen, Germany
| | - Timothy Newton
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - Sven Günther
- Department of Clinical Chemistry and Laboratory Diagnostics, Jena University Hospital, 07743 Jena, Germany
| | - Fiamma Berner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - Jennifer Hague
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - James W Connell
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK.,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
| | - Jürgen Winkler
- Department of Molecular Neurology, Friedrich-Alexander-University Erlangen-Nuernberg, 91054 Erlangen, Germany
| | | | - Christian Beetz
- Department of Clinical Chemistry and Laboratory Diagnostics, Jena University Hospital, 07743 Jena, Germany
| | - Beate Winner
- Interdisciplinary Center for Clinical Research (IZKF) Junior Research Group III and Federal Ministry of Education and Research (BMBF) Research Group Neuroscience, Friedrich-Alexander-University Erlangen-Nuernberg, 91054 Erlangen, Germany.,Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuernberg, 91054 Erlangen, Germany
| | - Evan Reid
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, England, UK .,Department of Medical Genetics, University of Cambridge, Cambridge CB2 0XY, England, UK
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Ohnishi T, Shirane M, Nakayama KI. SRRM4-dependent neuron-specific alternative splicing of protrudin transcripts regulates neurite outgrowth. Sci Rep 2017; 7:41130. [PMID: 28106138 PMCID: PMC5247714 DOI: 10.1038/srep41130] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/15/2016] [Indexed: 11/09/2022] Open
Abstract
Alternative splicing gives rise to diversity of the proteome, and it is especially prevalent in the mammalian nervous system. Indeed, many factors that control the splicing process govern nervous system development. Among such factors, SRRM4 is an important regulator of aspects of neural differentiation including neurite outgrowth. The mechanism by which SRRM4 regulates neurite outgrowth has remained poorly understood, however. We now show that SRRM4 regulates the splicing of protrudin gene (Zfyve27) transcripts in neuronal cells. SRRM4 was found to promote splicing of protrudin pre-mRNA so as to include a microexon (exon L) encoding seven amino acids in a neuron-specific manner. The resulting protein (protrudin-L) promotes neurite outgrowth during neurogenesis. Depletion of SRRM4 in Neuro2A cells impaired inclusion of exon L in protrudin mRNA, resulting in the generation of a shorter protein isoform (protrudin-S) that is less effective at promoting neurite extension. SRRM4 was found to recognize a UGC motif that is located immediately upstream of exon L and is necessary for inclusion of exon L in the mature transcript. Deletion of exon L in Neuro2A or embryonic stem cells inhibited neurite outgrowth. Our results suggest that SRRM4 controls neurite outgrowth through regulation of alternative splicing of protrudin transcripts.
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Affiliation(s)
- Takafumi Ohnishi
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Michiko Shirane
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
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Marras C, Lang A, van de Warrenburg BP, Sue CM, Tabrizi SJ, Bertram L, Mercimek-Mahmutoglu S, Ebrahimi-Fakhari D, Warner TT, Durr A, Assmann B, Lohmann K, Kostic V, Klein C. Nomenclature of genetic movement disorders: Recommendations of the international Parkinson and movement disorder society task force. Mov Disord 2016; 31:436-57. [PMID: 27079681 DOI: 10.1002/mds.26527] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 10/21/2015] [Accepted: 11/22/2015] [Indexed: 12/11/2022] Open
Abstract
The system of assigning locus symbols to specify chromosomal regions that are associated with a familial disorder has a number of problems when used as a reference list of genetically determined disorders,including (I) erroneously assigned loci, (II) duplicated loci, (III) missing symbols or loci, (IV) unconfirmed loci and genes, (V) a combination of causative genes and risk factor genes in the same list, and (VI) discordance between phenotype and list assignment. In this article, we report on the recommendations of the International Parkinson and Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders and present a system for naming genetically determined movement disorders that addresses these problems. We demonstrate how the system would be applied to currently known genetically determined parkinsonism, dystonia, dominantly inherited ataxia, spastic paraparesis, chorea, paroxysmal movement disorders, neurodegeneration with brain iron accumulation, and primary familial brain calcifications. This system provides a resource for clinicians and researchers that, unlike the previous system, can be considered an accurate and criterion-based list of confirmed genetically determined movement disorders at the time it was last updated.
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Affiliation(s)
- Connie Marras
- Toronto Western Hospital Morton, Gloria Shulman Movement Disorders Centre, and the Edmond J. Safra Program in Parkinson's Disease, University of Toronto, Toronto, Canada
| | - Anthony Lang
- Toronto Western Hospital Morton, Gloria Shulman Movement Disorders Centre, and the Edmond J. Safra Program in Parkinson's Disease, University of Toronto, Toronto, Canada
| | - Bart P van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Carolyn M Sue
- Department of Neurology, Royal North Shore Hospital and Kolling Institute of Medical Research, University of Sydney, St. Leonards, New South Wales, Australia
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, UK
| | - Lars Bertram
- Lübeck Interdisciplinary Platform for Genome Analytics (LIGA), Institutes of Neurogenetics and Integrative and Experimental Genomics, University of Lübeck, Lübeck, Germany
- School of Public Health, Faculty of Medicine, Imperial College, London, UK
| | - Saadet Mercimek-Mahmutoglu
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada
| | - Darius Ebrahimi-Fakhari
- Division of Pediatric Neurology and Inborn Errors of Metabolism, Department of Pediatrics, Heidelberg University Hospital, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
- Department of Neurology & F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Thomas T Warner
- Reta Lila Weston Institute of Neurological Studies, Department of Molecular Neurosciences, UCL Institute of Neurology, London, UK
| | - Alexandra Durr
- Sorbonne Université, UPMC, Inserm and Hôpital de la Salpêtrière, Département de Génétique et Cytogénétique, Paris, France
| | - Birgit Assmann
- Division of Pediatric Neurology, Department of Pediatrics I, Heidelberg University Hospital, Ruprecht-Karls-University Heidelberg
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Vladimir Kostic
- Institute of Neurology, School of Medicine University of Belgrade, Belgrade, Serbia
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
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Di Fabio R, Storti E, Tessa A, Pierelli F, Morani F, Santorelli FM. Hereditary spastic paraplegia: pathology, genetics and therapeutic prospects. Expert Opin Orphan Drugs 2016. [DOI: 10.1517/21678707.2016.1153964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Carnitine palmitoyltransferase 1C: From cognition to cancer. Prog Lipid Res 2015; 61:134-48. [PMID: 26708865 DOI: 10.1016/j.plipres.2015.11.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/18/2015] [Accepted: 11/23/2015] [Indexed: 11/21/2022]
Abstract
Carnitine palmitoyltransferase 1 (CPT1) C was the last member of the CPT1 family of genes to be discovered. CPT1A and CPT1B were identified as the gate-keeper enzymes for the entry of long-chain fatty acids (as carnitine esters) into mitochondria and their further oxidation, and they show differences in their kinetics and tissue expression. Although CPT1C exhibits high sequence similarity to CPT1A and CPT1B, it is specifically expressed in neurons (a cell-type that does not use fatty acids as fuel to any major extent), it is localized in the endoplasmic reticulum of cells, and it has minimal CPT1 catalytic activity with l-carnitine and acyl-CoA esters. The lack of an easily measurable biological activity has hampered attempts to elucidate the cellular and physiological role of CPT1C but has not diminished the interest of the biomedical research community in this CPT1 isoform. The observations that CPT1C binds malonyl-CoA and long-chain acyl-CoA suggest that it is a sensor of lipid metabolism in neurons, where it appears to impact ceramide and triacylglycerol (TAG) metabolism. CPT1C global knock-out mice show a wide range of brain disorders, including impaired cognition and spatial learning, motor deficits, and a deregulation in food intake and energy homeostasis. The first disease-causing CPT1C mutation was recently described in humans, with Cpt1c being identified as the gene causing hereditary spastic paraplegia. The putative role of CPT1C in the regulation of complex-lipid metabolism is supported by the observation that it is highly expressed in certain virulent tumor cells, conferring them resistance to glucose- and oxygen-deprivation. Therefore, CPT1C may be a promising target in the treatment of cancer. Here we review the molecular, biochemical, and structural properties of CPT1C and discuss its potential roles in brain function, and cancer.
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Raiborg C, Wenzel EM, Stenmark H. ER-endosome contact sites: molecular compositions and functions. EMBO J 2015; 34:1848-58. [PMID: 26041457 DOI: 10.15252/embj.201591481] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 03/31/2015] [Indexed: 01/05/2023] Open
Abstract
Recent studies have revealed the existence of numerous contact sites between the endoplasmic reticulum (ER) and endosomes in mammalian cells. Such contacts increase during endosome maturation and play key roles in cholesterol transfer, endosome positioning, receptor dephosphorylation, and endosome fission. At least 7 distinct contact sites between the ER and endosomes have been identified to date, which have diverse molecular compositions. Common to these contact sites is that they impose a close apposition between the ER and endosome membranes, which excludes membrane fusion while allowing the flow of molecular signals between the two membranes, in the form of enzymatic modifications, or ion, lipid, or protein transfer. Thus, ER-endosome contact sites ensure coordination of molecular activities between the two compartments while keeping their general compositions intact. Here, we review the molecular architectures and cellular functions of known ER-endosome contact sites and discuss their implications for human health.
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Affiliation(s)
- Camilla Raiborg
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research Oslo University Hospital, Oslo, Norway
| | - Eva M Wenzel
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research Oslo University Hospital, Oslo, Norway
| | - Harald Stenmark
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research Oslo University Hospital, Oslo, Norway Centre of Molecular Inflammation Research, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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48
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Klebe S, Stevanin G, Depienne C. Clinical and genetic heterogeneity in hereditary spastic paraplegias: from SPG1 to SPG72 and still counting. Rev Neurol (Paris) 2015; 171:505-30. [PMID: 26008818 DOI: 10.1016/j.neurol.2015.02.017] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/19/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSPs) are genetically determined neurodegenerative disorders characterized by progressive weakness and spasticity of lower limbs, and are among the most clinically and genetically heterogeneous human diseases. All modes of inheritance have been described, and the recent technological revolution in molecular genetics has led to the identification of 76 different spastic gait disease-loci with 59 corresponding spastic paraplegia genes. Autosomal recessive HSP are usually associated with diverse additional features (referred to as complicated forms), contrary to autosomal dominant HSP, which are mostly pure. However, the identification of additional mutations and families has considerably enlarged the clinical spectra, and has revealed a huge clinical variability for almost all HSP; complicated forms have also been described for primary pure HSP subtypes, adding further complexity to the genotype-phenotype correlations. In addition, the introduction of next generation sequencing in clinical practice has revealed a genetic and phenotypic overlap with other neurodegenerative disorders (amyotrophic lateral sclerosis, neuropathies, cerebellar ataxias, etc.) and neurodevelopmental disorders, including intellectual disability. This review aims to describe the most recent advances in the field and to provide genotype-phenotype correlations that could help clinical diagnoses of this heterogeneous group of disorders.
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Affiliation(s)
- S Klebe
- Department of neurology, university hospital Würzburg, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
| | - G Stevanin
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; École pratique des hautes études, 4-14, rue Ferrus, 75014 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France
| | - C Depienne
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France.
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Delving into the complexity of hereditary spastic paraplegias: how unexpected phenotypes and inheritance modes are revolutionizing their nosology. Hum Genet 2015; 134:511-38. [PMID: 25758904 PMCID: PMC4424374 DOI: 10.1007/s00439-015-1536-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/23/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSP) are rare neurodegenerative diseases sharing the degeneration of the corticospinal tracts as the main pathological characteristic. They are considered one of the most heterogeneous neurological disorders. All modes of inheritance have been described for the 84 different loci and 67 known causative genes implicated up to now. Recent advances in molecular genetics have revealed clinico-genetic heterogeneity of these disorders including their clinical and genetic overlap with other diseases of the nervous system. The systematic analysis of a large set of genes, including exome sequencing, is unmasking unusual phenotypes or inheritance modes associated with mutations in HSP genes and related genes involved in various neurological diseases. A new nosology may emerge after integration and understanding of these new data to replace the current classification. Collectively, functions of the known genes implicate the disturbance of intracellular membrane dynamics and trafficking as the consequence of alterations of cytoskeletal dynamics, lipid metabolism and organelle structures, which represent in fact a relatively small number of cellular processes that could help to find common curative approaches, which are still lacking.
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