1
|
Grass T, Dokuzluoglu Z, Buchner F, Rosignol I, Thomas J, Caldarelli A, Dalinskaya A, Becker J, Rost F, Marass M, Wirth B, Beyer M, Bonaguro L, Rodriguez-Muela N. Isogenic patient-derived organoids reveal early neurodevelopmental defects in spinal muscular atrophy initiation. Cell Rep Med 2024; 5:101659. [PMID: 39067446 PMCID: PMC11384962 DOI: 10.1016/j.xcrm.2024.101659] [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: 07/25/2023] [Revised: 02/26/2024] [Accepted: 07/02/2024] [Indexed: 07/30/2024]
Abstract
Whether neurodevelopmental defects underlie postnatal neuronal death in neurodegeneration is an intriguing hypothesis only recently explored. Here, we focus on spinal muscular atrophy (SMA), a neuromuscular disorder caused by reduced survival of motor neuron (SMN) protein levels leading to spinal motor neuron (MN) loss and muscle wasting. Using the first isogenic patient-derived induced pluripotent stem cell (iPSC) model and a spinal cord organoid (SCO) system, we show that SMA SCOs exhibit abnormal morphological development, reduced expression of early neural progenitor markers, and accelerated expression of MN progenitor and MN markers. Longitudinal single-cell RNA sequencing reveals marked defects in neural stem cell specification and fewer MNs, favoring mesodermal progenitors and muscle cells, a bias also seen in early SMA mouse embryos. Surprisingly, SMN2-to-SMN1 conversion does not fully reverse these developmental abnormalities. These suggest that early neurodevelopmental defects may underlie later MN degeneration, indicating that postnatal SMN-increasing interventions might not completely amend SMA pathology in all patients.
Collapse
Affiliation(s)
- Tobias Grass
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany.
| | - Zeynep Dokuzluoglu
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany
| | - Felix Buchner
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany
| | - Ines Rosignol
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany; Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Joshua Thomas
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany
| | - Antonio Caldarelli
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany
| | - Anna Dalinskaya
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany
| | - Jutta Becker
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Fabian Rost
- DRESDEN-concept Genome Center, Technology Platform at the Center for Molecular and Cellular Bioengineering, TUD, Dresden, Germany
| | - Michele Marass
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany; Center for Systems Biology Dresden, Dresden, Germany
| | - Brunhilde Wirth
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Center for Rare Diseases, University Hospital of Cologne, Cologne, Germany
| | - Marc Beyer
- Systems Medicine, DZNE, Bonn, Germany; PRECISE Platform for Single Cell Genomics and Epigenomics, DZNE & University of Bonn and West German Genome Center, Bonn, Germany; Immunogenomics & Neurodegeneration, DZNE, Bonn, Germany
| | - Lorenzo Bonaguro
- Systems Medicine, DZNE, Bonn, Germany; Genomics & Immunoregulation, LIMES Institute, University of Bonn, Bonn, Germany
| | - Natalia Rodriguez-Muela
- German Center for Neurodegenerative Diseases e.V. (DZNE), Dresden, Germany; Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden, Dresden, Germany; Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
| |
Collapse
|
2
|
Kannan A, Gangadharan Leela S, Branzei D, Gangwani L. Role of senataxin in R-loop-mediated neurodegeneration. Brain Commun 2024; 6:fcae239. [PMID: 39070547 PMCID: PMC11277865 DOI: 10.1093/braincomms/fcae239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 06/14/2024] [Accepted: 07/13/2024] [Indexed: 07/30/2024] Open
Abstract
Senataxin is an RNA:DNA helicase that plays an important role in the resolution of RNA:DNA hybrids (R-loops) formed during transcription. R-loops are involved in the regulation of biological processes such as immunoglobulin class switching, gene expression and DNA repair. Excessive accumulation of R-loops results in DNA damage and loss of genomic integrity. Senataxin is critical for maintaining optimal levels of R-loops to prevent DNA damage and acts as a genome guardian. Within the nucleus, senataxin interacts with various RNA processing factors and DNA damage response and repair proteins. Senataxin interactors include survival motor neuron and zinc finger protein 1, with whom it co-localizes in sub-nuclear bodies. Despite its ubiquitous expression, mutations in senataxin specifically affect neurons and result in distinct neurodegenerative diseases such as amyotrophic lateral sclerosis type 4 and ataxia with oculomotor apraxia type 2, which are attributed to the gain-of-function and the loss-of-function mutations in senataxin, respectively. In addition, low levels of senataxin (loss-of-function) in spinal muscular atrophy result in the accumulation of R-loops causing DNA damage and motor neuron degeneration. Senataxin may play multiple functions in diverse cellular processes; however, its emerging role in R-loop resolution and maintenance of genomic integrity is gaining attention in the field of neurodegenerative diseases. In this review, we highlight the role of senataxin in R-loop resolution and its potential as a therapeutic target to treat neurodegenerative diseases.
Collapse
Affiliation(s)
| | - Shyni Gangadharan Leela
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Dana Branzei
- The AIRC Institute of Molecular Oncology Foundation, IFOM ETS, Milan 20139, Italy
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Pavia 27100, Italy
| | - Laxman Gangwani
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| |
Collapse
|
3
|
Novikova ES. [Experience with the use of risdiplam in a familial case of spinal muscular atrophy 5q in patients with a homozygous deletion of the SMN1 gene and the same copy number of the SMN2 gene]. Zh Nevrol Psikhiatr Im S S Korsakova 2024; 124:138-141. [PMID: 38884441 DOI: 10.17116/jnevro2024124051138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Advances in the treatment of spinal muscular atrophy (SMA) have revolutionized the field. SMA is a rare autosomal recessive neurodegenerative motor neuron disease in which wide phenotypic variability has been described. The rate of increase in neurological deficit and the severity of the disease is mainly determined by the amount of functional SMN (Survival of Motor Neuron) protein. However, the clinical picture may differ significantly in patients carrying homozygous deletions of the SMN1 gene (Survival of Motor Neuron 1) and an identical number of copies of the SMN2 gene (Survival of Motor Neuron 2). A family clinical case of adult patients with spinal muscular atrophy 5q with a homozygous deletion of the SMN1 gene and the same number of copies of the SMN2 gene, having a different clinical picture of the disease, is presented, and the dynamics of the condition against the background of oral pathogenetic therapy is presented.
Collapse
Affiliation(s)
- E S Novikova
- Vladimirsky Moscow Regional Research and Clinical Institute, Moscow, Russia
| |
Collapse
|
4
|
El Khoury M, Biondi O, Bruneteau G, Sapaly D, Bendris S, Bezier C, Clerc Z, Akar EA, Weill L, Eid AA, Charbonnier F. NADPH oxidase 4 inhibition is a complementary therapeutic strategy for spinal muscular atrophy. Front Cell Neurosci 2023; 17:1242828. [PMID: 37780204 PMCID: PMC10536974 DOI: 10.3389/fncel.2023.1242828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Spinal muscular atrophy (SMA) is a fatal neurodegenerative disorder, characterized by motor neuron (MN) degeneration and severe muscular atrophy and caused by Survival of Motor Neuron (SMN) depletion. Therapies aimed at increasing SMN in patients have proven their efficiency in alleviating SMA symptoms but not for all patients. Thus, combinational therapies are warranted. Here, we investigated the involvement of NADPH oxidase 4 (NOX4) in SMA-induced spinal MN death and if the modulation of Nox4 activity could be beneficial for SMA patients. Methods We analysed in the spinal cord of severe type SMA-like mice before and at the disease onset, the level of oxidative stress and Nox4 expression. Then, we tested the effect of Nox4 inhibition by GKT137831/Setanaxib, a drug presently in clinical development, by intrathecal injection on MN survival and motor behaviour. Finally, we tested if GKT137831/Setanaxib could act synergistically with FDA-validated SMN-upregulating treatment (nusinersen). Results We show that NOX4 is overexpressed in SMA and its inhibition by GKT137831/Setanaxib protected spinal MN from SMA-induced degeneration. These improvements were associated with a significant increase in lifespan and motor behaviour of the mice. At the molecular level, GKT137831 activated the pro-survival AKT/CREB signaling pathway, leading to an increase in SMN expression in SMA MNs. Most importantly, we found that the per os administration of GKT137831 acted synergistically with a FDA-validated SMN-upregulating treatment. Conclusion The pharmacological inhibition of NOX4 by GKT137831/Setanaxib is neuroprotector and could represent a complementary therapeutic strategy to fight against SMA.
Collapse
Affiliation(s)
- Mirella El Khoury
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Olivier Biondi
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Gaelle Bruneteau
- Centre de Recherche en Myologie, UMRS974, Association Institut de Myologie, Sorbonne Université, INSERM, Paris, France
- Département de Neurologie, Centre référent SLA, APHP, Hôpital Pitié-Salpêtrière, Paris, France
| | - Delphine Sapaly
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Sabrina Bendris
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Cynthia Bezier
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Zoé Clerc
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Elias Abi Akar
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Laure Weill
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| | - Assaad A. Eid
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Frédéric Charbonnier
- Faculty of Basic and Biomedical Sciences, University Paris Cité & Inserm UMR_S1124, Paris, France
| |
Collapse
|
5
|
Fortuna TR, Kour S, Chimata AV, Muiños-Bühl A, Anderson EN, Nelson Iv CH, Ward C, Chauhan O, O'Brien C, Rajasundaram D, Rajan DS, Wirth B, Singh A, Pandey UB. SMN regulates GEMIN5 expression and acts as a modifier of GEMIN5-mediated neurodegeneration. Acta Neuropathol 2023; 146:477-498. [PMID: 37369805 PMCID: PMC11348892 DOI: 10.1007/s00401-023-02607-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 06/29/2023]
Abstract
GEMIN5 is essential for core assembly of small nuclear Ribonucleoproteins (snRNPs), the building blocks of spliceosome formation. Loss-of-function mutations in GEMIN5 lead to a neurodevelopmental syndrome among patients presenting with developmental delay, motor dysfunction, and cerebellar atrophy by perturbing SMN complex protein expression and assembly. Currently, molecular determinants of GEMIN5-mediated disease have yet to be explored. Here, we identified SMN as a genetic suppressor of GEMIN5-mediated neurodegeneration in vivo. We discovered that an increase in SMN expression by either SMN gene therapy replacement or the antisense oligonucleotide (ASO), Nusinersen, significantly upregulated the endogenous levels of GEMIN5 in mammalian cells and mutant GEMIN5-derived iPSC neurons. Further, we identified a strong functional association between the expression patterns of SMN and GEMIN5 in patient Spinal Muscular Atrophy (SMA)-derived motor neurons harboring loss-of-function mutations in the SMN gene. Interestingly, SMN binds to the C-terminus of GEMIN5 and requires the Tudor domain for GEMIN5 binding and expression regulation. Finally, we show that SMN upregulation ameliorates defective snRNP biogenesis and alternative splicing defects caused by loss of GEMIN5 in iPSC neurons and in vivo. Collectively, these studies indicate that SMN acts as a regulator of GEMIN5 expression and neuropathologies.
Collapse
Affiliation(s)
- Tyler R Fortuna
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Sukhleen Kour
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | | | - Anixa Muiños-Bühl
- Institute of Human Genetics, Center for Molecular Medicine, Center for Rare Disorders, University of Cologne, Cologne, Germany
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Charlie H Nelson Iv
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Caroline Ward
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Om Chauhan
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Casey O'Brien
- Department of Pediatrics, Division of Health Informatics, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Dhivyaa Rajasundaram
- Department of Pediatrics, Division of Health Informatics, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Deepa S Rajan
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine, Center for Rare Disorders, University of Cologne, Cologne, Germany
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, OH, USA
| | - Udai Bhan Pandey
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
- Children's Neuroscience Institute, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
6
|
Lumpkin CJ, Harris AW, Connell AJ, Kirk RW, Whiting JA, Saieva L, Pellizzoni L, Burghes AHM, Butchbach MER. Evaluation of the orally bioavailable 4-phenylbutyrate-tethered trichostatin A analogue AR42 in models of spinal muscular atrophy. Sci Rep 2023; 13:10374. [PMID: 37365234 PMCID: PMC10293174 DOI: 10.1038/s41598-023-37496-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 06/22/2023] [Indexed: 06/28/2023] Open
Abstract
Proximal spinal muscular atrophy (SMA) is a leading genetic cause for infant death in the world and results from the selective loss of motor neurons in the spinal cord. SMA is a consequence of low levels of SMN protein and small molecules that can increase SMN expression are of considerable interest as potential therapeutics. Previous studies have shown that both 4-phenylbutyrate (4PBA) and trichostatin A (TSA) increase SMN expression in dermal fibroblasts derived from SMA patients. AR42 is a 4PBA-tethered TSA derivative that is a very potent histone deacetylase inhibitor. SMA patient fibroblasts were treated with either AR42, AR19 (a related analogue), 4PBA, TSA or vehicle for 5 days and then immunostained for SMN localization. AR42 as well as 4PBA and TSA increased the number of SMN-positive nuclear gems in a dose-dependent manner while AR19 did not show marked changes in gem numbers. While gem number was increased in AR42-treated SMA fibroblasts, there were no significant changes in FL-SMN mRNA or SMN protein. The neuroprotective effect of this compound was then assessed in SMNΔ7 SMA (SMN2+/+;SMNΔ7+/+;mSmn-/-) mice. Oral administration of AR42 prior to disease onset increased the average lifespan of SMNΔ7 SMA mice by ~ 27% (20.1 ± 1.6 days for AR42-treated mice vs. 15.8 ± 0.4 days for vehicle-treated mice). AR42 treatment also improved motor function in these mice. AR42 treatment inhibited histone deacetylase (HDAC) activity in treated spinal cord although it did not affect SMN protein expression in these mice. AKT and GSK3β phosphorylation were both significantly increased in SMNΔ7 SMA mouse spinal cords. In conclusion, presymptomatic administration of the HDAC inhibitor AR42 ameliorates the disease phenotype in SMNΔ7 SMA mice in a SMN-independent manner possibly by increasing AKT neuroprotective signaling.
Collapse
Affiliation(s)
- Casey J Lumpkin
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Ashlee W Harris
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Andrew J Connell
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Ryan W Kirk
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Joshua A Whiting
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Luciano Saieva
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Livio Pellizzoni
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
| | - Arthur H M Burghes
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Matthew E R Butchbach
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA.
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
7
|
Stott J, Wright T, Holmes J, Wilson J, Griffiths-Jones S, Foster D, Wright B. A systematic review of non-coding RNA genes with differential expression profiles associated with autism spectrum disorders. PLoS One 2023; 18:e0287131. [PMID: 37319303 PMCID: PMC10270643 DOI: 10.1371/journal.pone.0287131] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023] Open
Abstract
AIMS To identify differential expression of shorter non-coding RNA (ncRNA) genes associated with autism spectrum disorders (ASD). BACKGROUND ncRNA are functional molecules that derive from non-translated DNA sequence. The HUGO Gene Nomenclature Committee (HGNC) have approved ncRNA gene classes with alignment to the reference human genome. One subset is microRNA (miRNA), which are highly conserved, short RNA molecules that regulate gene expression by direct post-transcriptional repression of messenger RNA. Several miRNA genes are implicated in the development and regulation of the nervous system. Expression of miRNA genes in ASD cohorts have been examined by multiple research groups. Other shorter classes of ncRNA have been examined less. A comprehensive systematic review examining expression of shorter ncRNA gene classes in ASD is timely to inform the direction of research. METHODS We extracted data from studies examining ncRNA gene expression in ASD compared with non-ASD controls. We included studies on miRNA, piwi-interacting RNA (piRNA), small NF90 (ILF3) associated RNA (snaR), small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), transfer RNA (tRNA), vault RNA (vtRNA) and Y RNA. The following electronic databases were searched: Cochrane Library, EMBASE, PubMed, Web of Science, PsycINFO, ERIC, AMED and CINAHL for papers published from January 2000 to May 2022. Studies were screened by two independent investigators with a third resolving discrepancies. Data was extracted from eligible papers. RESULTS Forty-eight eligible studies were included in our systematic review with the majority examining miRNA gene expression alone. Sixty-four miRNA genes had differential expression in ASD compared to controls as reported in two or more studies, but often in opposing directions. Four miRNA genes had differential expression in the same direction in the same tissue type in at least 3 separate studies. Increased expression was reported in miR-106b-5p, miR-155-5p and miR-146a-5p in blood, post-mortem brain, and across several tissue types, respectively. Decreased expression was reported in miR-328-3p in bloods samples. Seven studies examined differential expression from other classes of ncRNA, including piRNA, snRNA, snoRNA and Y RNA. No individual ncRNA genes were reported in more than one study. Six studies reported differentially expressed snoRNA genes in ASD. A meta-analysis was not possible because of inconsistent methodologies, disparate tissue types examined, and varying forms of data presented. CONCLUSION There is limited but promising evidence associating the expression of certain miRNA genes and ASD, although the studies are of variable methodological quality and the results are largely inconsistent. There is emerging evidence associating differential expression of snoRNA genes in ASD. It is not currently possible to say whether the reports of differential expression in ncRNA may relate to ASD aetiology, a response to shared environmental factors linked to ASD such as sleep and nutrition, other molecular functions, human diversity, or chance findings. To improve our understanding of any potential association, we recommend improved and standardised methodologies and reporting of raw data. Further high-quality research is required to shine a light on possible associations, which may yet yield important information.
Collapse
Affiliation(s)
- Jon Stott
- Child Oriented Mental Health Intervention Collaborative (COMIC), University of York in Collaboration with Leeds and York Partnership NHS Foundation Trust, York, United Kingdom
- Tees, Esk & Wear Valleys NHS Foundation Trust, Foss Park Hospital, York, United Kingdom
| | - Thomas Wright
- Manchester Centre for Genomic Medicine, Clinical Genetics Service, Saint Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jannah Holmes
- Child Oriented Mental Health Intervention Collaborative (COMIC), University of York in Collaboration with Leeds and York Partnership NHS Foundation Trust, York, United Kingdom
- Hull York Medical School, University of York, Heslington, York, United Kingdom
| | - Julie Wilson
- Department of Mathematics, University of York, Heslington, York, United Kingdom
| | - Sam Griffiths-Jones
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Deborah Foster
- Tees, Esk & Wear Valleys NHS Foundation Trust, Foss Park Hospital, York, United Kingdom
| | - Barry Wright
- Child Oriented Mental Health Intervention Collaborative (COMIC), University of York in Collaboration with Leeds and York Partnership NHS Foundation Trust, York, United Kingdom
- Hull York Medical School, University of York, Heslington, York, United Kingdom
| |
Collapse
|
8
|
Riboldi GM, Faravelli I, Rinchetti P, Lotti F. SMN post-translational modifications in spinal muscular atrophy. Front Cell Neurosci 2023; 17:1092488. [PMID: 36874214 PMCID: PMC9981653 DOI: 10.3389/fncel.2023.1092488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/26/2023] [Indexed: 02/19/2023] Open
Abstract
Since its first identification as the gene responsible for spinal muscular atrophy (SMA), the range of survival motor neuron (SMN) protein functions has increasingly expanded. This multimeric complex plays a crucial role in a variety of RNA processing pathways. While its most characterized function is in the biogenesis of ribonucleoproteins, several studies have highlighted the SMN complex as an important contributor to mRNA trafficking and translation, axonal transport, endocytosis, and mitochondria metabolism. All these multiple functions need to be selectively and finely modulated to maintain cellular homeostasis. SMN has distinct functional domains that play a crucial role in complex stability, function, and subcellular distribution. Many different processes were reported as modulators of the SMN complex activities, although their contribution to SMN biology still needs to be elucidated. Recent evidence has identified post-translational modifications (PTMs) as a way to regulate the pleiotropic functions of the SMN complex. These modifications include phosphorylation, methylation, ubiquitination, acetylation, sumoylation, and many other types. PTMs can broaden the range of protein functions by binding chemical moieties to specific amino acids, thus modulating several cellular processes. Here, we provide an overview of the main PTMs involved in the regulation of the SMN complex with a major focus on the functions that have been linked to SMA pathogenesis.
Collapse
Affiliation(s)
| | | | | | - Francesco Lotti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY, United States
| |
Collapse
|
9
|
Faravelli I, Riboldi GM, Rinchetti P, Lotti F. The SMN Complex at the Crossroad between RNA Metabolism and Neurodegeneration. Int J Mol Sci 2023; 24:2247. [PMID: 36768569 PMCID: PMC9917330 DOI: 10.3390/ijms24032247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
In the cell, RNA exists and functions in a complex with RNA binding proteins (RBPs) that regulate each step of the RNA life cycle from transcription to degradation. Central to this regulation is the role of several molecular chaperones that ensure the correct interactions between RNA and proteins, while aiding the biogenesis of large RNA-protein complexes (ribonucleoproteins or RNPs). Accurate formation of RNPs is fundamentally important to cellular development and function, and its impairment often leads to disease. The survival motor neuron (SMN) protein exemplifies this biological paradigm. SMN is part of a multi-protein complex essential for the biogenesis of various RNPs that function in RNA metabolism. Mutations leading to SMN deficiency cause the neurodegenerative disease spinal muscular atrophy (SMA). A fundamental question in SMA biology is how selective motor system dysfunction results from reduced levels of the ubiquitously expressed SMN protein. Recent clarification of the central role of the SMN complex in RNA metabolism and a thorough characterization of animal models of SMA have significantly advanced our knowledge of the molecular basis of the disease. Here we review the expanding role of SMN in the regulation of gene expression through its multiple functions in RNP biogenesis. We discuss developments in our understanding of SMN activity as a molecular chaperone of RNPs and how disruption of SMN-dependent RNA pathways can contribute to the SMA phenotype.
Collapse
Affiliation(s)
- Irene Faravelli
- Department of Stem Cell & Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Giulietta M. Riboldi
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
- The Marlene and Paolo Fresco Institute for Parkinson’s and Movement Disorders, NYU Langone Health, New York, NY 10017, USA
| | - Paola Rinchetti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Francesco Lotti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| |
Collapse
|
10
|
SMN controls neuromuscular junction integrity through U7 snRNP. Cell Rep 2022; 40:111393. [PMID: 36130491 PMCID: PMC9533342 DOI: 10.1016/j.celrep.2022.111393] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/18/2022] [Accepted: 08/30/2022] [Indexed: 01/26/2023] Open
Abstract
The neuromuscular junction (NMJ) is an essential synapse whose loss is a key hallmark of the neurodegenerative disease spinal muscular atrophy (SMA). Here, we show that activity of the SMA-determining SMN protein in the assembly of U7 small nuclear ribonucleoprotein (snRNP)—which functions in the 3′-end processing of replication-dependent histone mRNAs—is required for NMJ integrity. Co-expression of U7-specific Lsm10 and Lsm11 proteins selectively enhances U7 snRNP assembly, corrects histone mRNA processing defects, and rescues key structural and functional abnormalities of neuromuscular pathology in SMA mice—including NMJ denervation, decreased synaptic transmission, and skeletal muscle atrophy. Furthermore, U7 snRNP dysfunction drives selective loss of the synaptic organizing protein Agrin at NMJs innervating vulnerable muscles of SMA mice. These findings reveal a direct contribution of U7 snRNP dysfunction to neuromuscular pathology in SMA and suggest a role for histone gene regulation in maintaining functional synaptic connections between motor neurons and muscles. NMJ denervation is a hallmark of SMA. Through selective restoration of U7 snRNP biogenesis in SMA mice, Tisdale et al. reveal a role for SMN-mediated U7 snRNP assembly and histone mRNA processing in controlling NMJ integrity through Agrin expression, uncovering RNA-mediated disease mechanisms and linking U7 function to neuromuscular development.
Collapse
|
11
|
Detering NT, Schüning T, Hensel N, Claus P. The phospho-landscape of the survival of motoneuron protein (SMN) protein: relevance for spinal muscular atrophy (SMA). Cell Mol Life Sci 2022; 79:497. [PMID: 36006469 PMCID: PMC11071818 DOI: 10.1007/s00018-022-04522-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/27/2022] [Accepted: 08/09/2022] [Indexed: 11/03/2022]
Abstract
Spinal muscular atrophy (SMA) is caused by low levels of the survival of motoneuron (SMN) Protein leading to preferential degeneration of lower motoneurons in the ventral horn of the spinal cord and brain stem. However, the SMN protein is ubiquitously expressed and there is growing evidence of a multisystem phenotype in SMA. Since a loss of SMN function is critical, it is important to decipher the regulatory mechanisms of SMN function starting on the level of the SMN protein itself. Posttranslational modifications (PTMs) of proteins regulate multiple functions and processes, including activity, cellular trafficking, and stability. Several PTM sites have been identified within the SMN sequence. Here, we map the identified SMN PTMs highlighting phosphorylation as a key regulator affecting localization, stability and functions of SMN. Furthermore, we propose SMN phosphorylation as a crucial factor for intracellular interaction and cellular distribution of SMN. We outline the relevance of phosphorylation of the spinal muscular atrophy (SMA) gene product SMN with regard to basic housekeeping functions of SMN impaired in this neurodegenerative disease. Finally, we compare SMA patient mutations with putative and verified phosphorylation sites. Thus, we emphasize the importance of phosphorylation as a cellular modulator in a clinical perspective as a potential additional target for combinatorial SMA treatment strategies.
Collapse
Affiliation(s)
- Nora Tula Detering
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Tobias Schüning
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Niko Hensel
- Ottawa Hospital Research Institute (OHRI), Ottawa, Canada
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Peter Claus
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany.
- Center for Systems Neuroscience (ZSN), Hannover, Germany.
| |
Collapse
|
12
|
Zhang L, Abendroth F, Vázquez O. A Chemical Biology Perspective to Therapeutic Regulation of RNA Splicing in Spinal Muscular Atrophy (SMA). ACS Chem Biol 2022; 17:1293-1307. [PMID: 35639849 DOI: 10.1021/acschembio.2c00161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Manipulation of RNA splicing machinery has emerged as a drug modality. Here, we illustrate the potential of this novel paradigm to correct aberrant splicing events focused on the recent therapeutic advances in spinal muscular atrophy (SMA). SMA is an incurable neuromuscular disorder and at present the primary genetic cause of early infant death. This Review summarizes the exciting journey from the first reported SMA cases to the currently approved splicing-switching treatments, i.e., antisense oligonucleotides and small-molecule modifiers. We emphasize both chemical structures and molecular bases for recognition. We briefly discuss the advantages and disadvantages of these treatments and include the remaining challenges and future directions. Finally, we also predict that these success stories will contribute to further therapies for human diseases by RNA-splicing control.
Collapse
Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| | - Frank Abendroth
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| | - Olalla Vázquez
- Department of Chemistry, University of Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), University of Marburg, Karl-von-Frisch-Straße 14, 35043 Marburg, Germany
| |
Collapse
|
13
|
Kim JH, Kang JS, Yoo K, Jeong J, Park I, Park JH, Rhee J, Jeon S, Jo YW, Hann SH, Seo M, Moon S, Um SJ, Seong RH, Kong YY. Bap1/SMN axis in Dpp4+ skeletal muscle mesenchymal cells regulates the neuromuscular system. JCI Insight 2022; 7:158380. [PMID: 35603786 PMCID: PMC9220848 DOI: 10.1172/jci.insight.158380] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 04/06/2022] [Indexed: 12/15/2022] Open
Abstract
The survival of motor neuron (SMN) protein is a major component of the pre-mRNA splicing machinery and is required for RNA metabolism. Although SMN has been considered a fundamental gene for the central nervous system, due to its relationship with neuromuscular diseases, such as spinal muscular atrophy, recent studies have also revealed the requirement of SMN in non-neuronal cells in the peripheral regions. Here, we report that the fibro-adipogenic progenitor subpopulation expressing Dpp4 (Dpp4+ FAPs) is required for the neuromuscular system. Furthermore, we also reveal that BRCA1-associated protein-1 (Bap1) is crucial for the stabilization of SMN in FAPs by preventing its ubiquitination-dependent degradation. Inactivation of Bap1 in FAPs decreased SMN levels and accompanied degeneration of the neuromuscular junction, leading to loss of motor neurons and muscle atrophy. Overexpression of the ubiquitination-resistant SMN variant, SMNK186R, in Bap1-null FAPs completely prevented neuromuscular degeneration. In addition, transplantation of Dpp4+ FAPs, but not Dpp4– FAPs, completely rescued neuromuscular defects. Our data reveal the crucial role of Bap1-mediated SMN stabilization in Dpp4+ FAPs for the neuromuscular system and provide the possibility of cell-based therapeutics to treat neuromuscular diseases.
Collapse
Affiliation(s)
- Ji-Hoon Kim
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Molecular Recognition Research Center, Korea Institute of Science and Technology, Seoul, South Korea
| | - Jong-Seol Kang
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Kyusang Yoo
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Jinguk Jeong
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Inkuk Park
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Jong Ho Park
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Joonwoo Rhee
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Shin Jeon
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Young-Woo Jo
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Sang-Hyeon Hann
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Minji Seo
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Seungtae Moon
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, South Korea
| | - Soo-Jong Um
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, South Korea
| | - Rho Hyun Seong
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Young-Yun Kong
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| |
Collapse
|
14
|
Bizen N, Bepari AK, Zhou L, Abe M, Sakimura K, Ono K, Takebayashi H. Ddx20, an Olig2 binding factor, governs the survival of neural and oligodendrocyte progenitor cells via proper Mdm2 splicing and p53 suppression. Cell Death Differ 2022; 29:1028-1041. [PMID: 34974536 PMCID: PMC9090832 DOI: 10.1038/s41418-021-00915-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/05/2021] [Accepted: 09/20/2021] [Indexed: 12/13/2022] Open
Abstract
Olig2 is indispensable for motoneuron and oligodendrocyte fate-specification in the pMN domain of embryonic spinal cords, and also involved in the proliferation and differentiation of several cell types in the nervous system, including neural progenitor cells (NPCs) and oligodendrocytes. However, how Olig2 controls these diverse biological processes remains unclear. Here, we demonstrated that a novel Olig2-binding protein, DEAD-box helicase 20 (Ddx20), is indispensable for the survival of NPCs and oligodendrocyte progenitor cells (OPCs). A central nervous system (CNS)-specific Ddx20 conditional knockout (cKO) demonstrated apoptosis and cell cycle arrest in NPCs and OPCs, through the potentiation of the p53 pathway in DNA damage-dependent and independent manners, including SMN complex disruption and the abnormal splicing of Mdm2 mRNA. Analyzes of Olig2 null NPCs showed that Olig2 contributed to NPC proliferation through Ddx20 protein stabilization. Our findings provide novel mechanisms underlying the Olig2-mediated proliferation of NPCs, via the Ddx20-p53 axis, in the embryonic CNS.
Collapse
Affiliation(s)
- Norihisa Bizen
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Asim K Bepari
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.,Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Li Zhou
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.,Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.,Center for Coordination of Research Facilities (CCRF), Niigata University, Niigata, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.,Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.,Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Katsuhiko Ono
- Developmental Neurobiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan. .,Center for Coordination of Research Facilities (CCRF), Niigata University, Niigata, Japan.
| |
Collapse
|
15
|
Jacquier V, Prévot M, Gostan T, Bordonné R, Benkhelifa-Ziyyat S, Barkats M, Soret J. Splicing efficiency of minor introns in a mouse model of SMA predominantly depends on their branchpoint sequence and can involve the contribution of major spliceosome components. RNA (NEW YORK, N.Y.) 2022; 28:303-319. [PMID: 34893560 PMCID: PMC8848931 DOI: 10.1261/rna.078329.120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/22/2021] [Indexed: 06/14/2023]
Abstract
Spinal muscular atrophy (SMA) is a devastating neurodegenerative disease caused by reduced amounts of the ubiquitously expressed Survival of Motor Neuron (SMN) protein. In agreement with its crucial role in the biogenesis of spliceosomal snRNPs, SMN-deficiency is correlated to numerous splicing alterations in patient cells and various tissues of SMA mouse models. Among the snRNPs whose assembly is impacted by SMN-deficiency, those involved in the minor spliceosome are particularly affected. Importantly, splicing of several, but not all U12-dependent introns has been shown to be affected in different SMA models. Here, we have investigated the molecular determinants of this differential splicing in spinal cords from SMA mice. We show that the branchpoint sequence (BPS) is a key element controlling splicing efficiency of minor introns. Unexpectedly, splicing of several minor introns with suboptimal BPS is not affected in SMA mice. Using in vitro splicing experiments and oligonucleotides targeting minor or major snRNAs, we show for the first time that splicing of these introns involves both the minor and major machineries. Our results strongly suggest that splicing of a subset of minor introns is not affected in SMA mice because components of the major spliceosome compensate for the loss of minor splicing activity.
Collapse
Affiliation(s)
- Valentin Jacquier
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France
| | - Manon Prévot
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France
| | - Thierry Gostan
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France
| | - Rémy Bordonné
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France
| | - Sofia Benkhelifa-Ziyyat
- Centre de Recherche en Myologie (CRM), Institut de Myologie, Sorbonne Universités, UPMC Univ Paris 06, Inserm UMRS974, GH Pitié Salpêtrière, Paris 75013, France
| | - Martine Barkats
- Centre de Recherche en Myologie (CRM), Institut de Myologie, Sorbonne Universités, UPMC Univ Paris 06, Inserm UMRS974, GH Pitié Salpêtrière, Paris 75013, France
| | - Johann Soret
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France
| |
Collapse
|
16
|
Jutzi D, Ruepp MD. Alternative Splicing in Human Biology and Disease. Methods Mol Biol 2022; 2537:1-19. [PMID: 35895255 DOI: 10.1007/978-1-0716-2521-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Alternative pre-mRNA splicing allows for the production of multiple mRNAs from an individual gene, which not only expands the protein-coding potential of the genome but also enables complex mechanisms for the post-transcriptional control of gene expression. Regulation of alternative splicing entails a combinatorial interplay between an abundance of trans-acting splicing factors, cis-acting regulatory sequence elements and their concerted effects on the core splicing machinery. Given the extent and biological significance of alternative splicing in humans, it is not surprising that aberrant splicing patterns can cause or contribute to a wide range of diseases. In this introductory chapter, we outline the mechanisms that govern alternative pre-mRNA splicing and its regulation and discuss how dysregulated splicing contributes to human diseases affecting the motor system and the brain.
Collapse
Affiliation(s)
- Daniel Jutzi
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK.
| | - Marc-David Ruepp
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK.
| |
Collapse
|
17
|
Ravel-Chapuis A, Haghandish A, Daneshvar N, Jasmin BJ, Côté J. A novel CARM1-HuR axis involved in muscle differentiation and plasticity misregulated in spinal muscular atrophy. Hum Mol Genet 2021; 31:1453-1470. [PMID: 34791230 DOI: 10.1093/hmg/ddab333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/14/2022] Open
Abstract
Spinal muscular atrophy (SMA) is characterized by the loss of alpha motor neurons in the spinal cord and a progressive muscle weakness and atrophy. SMA is caused by loss-of-function mutations and/or deletions in the survival of motor neuron (SMN) gene. The role of SMN in motor neurons has been extensively studied, but its function and the consequences of its loss in muscle has also emerged as a key aspect of SMA pathology. In this study, we explore the molecular mechanisms involved in muscle defects in SMA. First, we show in C2C12 myoblasts, that arginine methylation by CARM1 controls myogenic differentiation. More specifically, the methylation of HuR on K217 regulates HuR levels and subcellular localization during myogenic differentiation, and the formation of myotubes. Furthermore, we demonstrate that SMN and HuR interact in C2C12 myoblasts. Interestingly, the SMA-causing E134K point mutation within the SMN Tudor domain, and CARM1 depletion, modulate the SMN-HuR interaction. In addition, using the Smn2B/- mouse model, we report that CARM1 levels are markedly increased in SMA muscles and that HuR fails to properly respond to muscle denervation, thereby affecting the regulation of its mRNA targets. Altogether, our results show a novel CARM1-HuR axis in the regulation of muscle differentiation and plasticity as well as in the aberrant regulation of this axis caused by the absence of SMN in SMA muscle. With the recent developments of therapeutics targeting motor neurons, this study further indicates the need for more global therapeutic approaches for SMA.
Collapse
Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Amir Haghandish
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Nasibeh Daneshvar
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| |
Collapse
|
18
|
Choi K, Yang A, Baek J, Jeong H, Kang Y, Baek W, Kim JC, Kang M, Choi M, Ham Y, Son MJ, Han SB, Kim J, Jang JH, Ahn JS, Shen H, Woo SH, Kim JH, Cho S. Regulation of Survival Motor Neuron Gene Expression by Calcium Signaling. Int J Mol Sci 2021; 22:ijms221910234. [PMID: 34638572 PMCID: PMC8508836 DOI: 10.3390/ijms221910234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 11/21/2022] Open
Abstract
Spinal muscular atrophy (SMA) is caused by homozygous survival of motor neurons 1 (SMN1) gene deletion, leaving a duplicate gene, SMN2, as the sole source of SMN protein. However, a defect in SMN2 splicing, involving exon 7 skipping, results in a low level of functional SMN protein. Therefore, the upregulation of SMN protein expression from the SMN2 gene is generally considered to be one of the best therapeutic strategies to treat SMA. Most of the SMA drug discovery is based on synthetic compounds, and very few natural compounds have been explored thus far. Here, we performed an unbiased mechanism-independent and image-based screen of a library of microbial metabolites in SMA fibroblasts using an SMN-specific immunoassay. In doing so, we identified brefeldin A (BFA), a well-known inhibitor of ER-Golgi protein trafficking, as a strong inducer of SMN protein. The profound increase in SMN protein was attributed to, in part, the rescue of the SMN2 pre-mRNA splicing defect. Intriguingly, BFA increased the intracellular calcium concentration, and the BFA-induced exon 7 inclusion of SMN2 splicing, was abrogated by the depletion of intracellular calcium and by the pharmacological inhibition of calcium/calmodulin-dependent kinases (CaMKs). Moreover, BFA considerably reduced the expression of Tra2-β and SRSF9 proteins in SMA fibroblasts and enhanced the binding of PSF and hnRNP M to an exonic splicing enhancer (ESE) of exon 7. Together, our results demonstrate a significant role for calcium and its signaling on the regulation of SMN splicing, probably through modulating the expression/activity of splicing factors.
Collapse
Affiliation(s)
- Kwangman Choi
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Medical Biotechnology, SoonChunHyang University, Asan 31538, Korea
| | - Ansook Yang
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Jiyeon Baek
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Hyejeong Jeong
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Yura Kang
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Woosun Baek
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Joon-Chul Kim
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
| | - Mingu Kang
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Miri Choi
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Youngwook Ham
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
| | - Min-Jeong Son
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
| | - Sang-Bae Han
- College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea;
| | - Janghwan Kim
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea;
| | - Jae-Hyuk Jang
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea
| | - Jong Seog Ahn
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea
| | - Haihong Shen
- Gwangju Institute of Science and Technology, School of life Sciences, Gwangju 61005, Korea;
| | - Sun-Hee Woo
- College of Pharmacy, Chungnam National University, Daejeon 34134, Korea; (J.-C.K.); (M.-J.S.)
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
| | - Jong Heon Kim
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang 10408, Korea; (Y.K.); (W.B.)
- Cancer Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 10408, Korea
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
| | - Sungchan Cho
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea; (K.C.); (A.Y.); (J.B.); (H.J.); (M.K.); (M.C.); (Y.H.)
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon 34113, Korea; (J.-H.J.); (J.S.A.)
- Correspondence: (S.-H.W.); (J.H.K.); (S.C.); Tel.: +82-42-821-5924 (S.-H.W.); +82-31-920-2204 (J.H.K.); +82-43-240-6105 (S.C.); Fax: +82-42-823-6566 (S.-H.W.); +82-31-920-2006 (J.H.K.); +82-43-240-6159 (S.C)
| |
Collapse
|
19
|
Abstract
Autosomal-recessive spinal muscular atrophy (SMA) is characterized by the loss of specific motor neurons of the spinal cord and skeletal muscle atrophy. SMA is caused by mutations or deletions of the survival motor neuron 1 (SMN1) gene, and disease severity correlates with the expression levels of the nearly identical copy gene, SMN2. Both genes ubiquitously express SMN protein, but SMN2 generates only low levels of protein that do not fully compensate for the loss-of-function of SMN1. SMN protein forms a multiprotein complex essential for the cellular assembly of ribonucleoprotein particles involved in diverse aspects of RNA metabolism. Other studies using animal models revealed a spatio-temporal requirement of SMN that is high during the development of the neuromuscular system and later, in the general maintenance of cellular and tissues homeostasis. These observations define a period for maximum therapeutic efficiency of SMN restoration, and suggest that cells outside the central nervous system may also participate in the pathogenesis of SMA. Finally, recent innovative therapies have been shown to mitigate SMN deficiency and have been approved to treat SMA patients. We briefly review major findings from the past twenty-five years of SMA research. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.
Collapse
Affiliation(s)
- S Lefebvre
- T3S INSERM UMR 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, UFR des Sciences Fondamentales et Biomédicales, Campus Saint-Germain-des-prés, Université de Paris, Paris, France.
| | - C Sarret
- Centre de compétence maladies rares des pathologies neuromusculaires, service de génétique médicale, Hôpital Estaing, CHU Clermont-Ferrand, France.
| |
Collapse
|
20
|
Sumoylation regulates the assembly and activity of the SMN complex. Nat Commun 2021; 12:5040. [PMID: 34413305 PMCID: PMC8376998 DOI: 10.1038/s41467-021-25272-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/26/2021] [Indexed: 11/09/2022] Open
Abstract
SMN is a ubiquitously expressed protein and is essential for life. SMN deficiency causes the neurodegenerative disease spinal muscular atrophy (SMA), the leading genetic cause of infant mortality. SMN interacts with itself and other proteins to form a complex that functions in the assembly of ribonucleoproteins. SMN is modified by SUMO (Small Ubiquitin-like Modifier), but whether sumoylation is required for the functions of SMN that are relevant to SMA pathogenesis is not known. Here, we show that inactivation of a SUMO-interacting motif (SIM) alters SMN sub-cellular distribution, the integrity of its complex, and its function in small nuclear ribonucleoproteins biogenesis. Expression of a SIM-inactivated mutant of SMN in a mouse model of SMA slightly extends survival rate with limited and transient correction of motor deficits. Remarkably, although SIM-inactivated SMN attenuates motor neuron loss and improves neuromuscular junction synapses, it fails to prevent the loss of sensory-motor synapses. These findings suggest that sumoylation is important for proper assembly and function of the SMN complex and that loss of this post-translational modification impairs the ability of SMN to correct selective deficits in the sensory-motor circuit of SMA mice.
Collapse
|
21
|
Blatnik AJ, McGovern VL, Burghes AHM. What Genetics Has Told Us and How It Can Inform Future Experiments for Spinal Muscular Atrophy, a Perspective. Int J Mol Sci 2021; 22:8494. [PMID: 34445199 PMCID: PMC8395208 DOI: 10.3390/ijms22168494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 02/06/2023] Open
Abstract
Proximal spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder characterized by motor neuron loss and subsequent atrophy of skeletal muscle. SMA is caused by deficiency of the essential survival motor neuron (SMN) protein, canonically responsible for the assembly of the spliceosomal small nuclear ribonucleoproteins (snRNPs). Therapeutics aimed at increasing SMN protein levels are efficacious in treating SMA. However, it remains unknown how deficiency of SMN results in motor neuron loss, resulting in many reported cellular functions of SMN and pathways affected in SMA. Herein is a perspective detailing what genetics and biochemistry have told us about SMA and SMN, from identifying the SMA determinant region of the genome, to the development of therapeutics. Furthermore, we will discuss how genetics and biochemistry have been used to understand SMN function and how we can determine which of these are critical to SMA moving forward.
Collapse
Affiliation(s)
| | | | - Arthur H. M. Burghes
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Rightmire Hall, Room 168, 1060 Carmack Road, Columbus, OH 43210, USA; (A.J.B.III); (V.L.M.)
| |
Collapse
|
22
|
Minor Intron Splicing from Basic Science to Disease. Int J Mol Sci 2021; 22:ijms22116062. [PMID: 34199764 PMCID: PMC8199999 DOI: 10.3390/ijms22116062] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 01/14/2023] Open
Abstract
Pre-mRNA splicing is an essential step in gene expression and is catalyzed by two machineries in eukaryotes: the major (U2 type) and minor (U12 type) spliceosomes. While the majority of introns in humans are U2 type, less than 0.4% are U12 type, also known as minor introns (mi-INTs), and require a specialized spliceosome composed of U11, U12, U4atac, U5, and U6atac snRNPs. The high evolutionary conservation and apparent splicing inefficiency of U12 introns have set them apart from their major counterparts and led to speculations on the purpose for their existence. However, recent studies challenged the simple concept of mi-INTs splicing inefficiency due to low abundance of their spliceosome and confirmed their regulatory role in alternative splicing, significantly impacting the expression of their host genes. Additionally, a growing list of minor spliceosome-associated diseases with tissue-specific pathologies affirmed the importance of minor splicing as a key regulatory pathway, which when deregulated could lead to tissue-specific pathologies due to specific alterations in the expression of some minor-intron-containing genes. Consequently, uncovering how mi-INTs splicing is regulated in a tissue-specific manner would allow for better understanding of disease pathogenesis and pave the way for novel therapies, which we highlight in this review.
Collapse
|
23
|
Targeting the 5' untranslated region of SMN2 as a therapeutic strategy for spinal muscular atrophy. MOLECULAR THERAPY. NUCLEIC ACIDS 2021; 23:731-742. [PMID: 33575118 PMCID: PMC7851419 DOI: 10.1016/j.omtn.2020.12.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/30/2020] [Indexed: 11/21/2022]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by mutations in the survival motor neuron 1 (SMN1) gene. All patients have at least one copy of a paralog, SMN2, but a C-to-T transition in this gene results in exon 7 skipping in a majority of transcripts. Approved treatment for SMA involves promoting exon 7 inclusion in the SMN2 transcript or increasing the amount of full-length SMN by gene replacement with a viral vector. Increasing the pool of SMN2 transcripts and increasing their translational efficiency can be used to enhance splice correction. We sought to determine whether the 5' untranslated region (5' UTR) of SMN2 contains a repressive feature that can be targeted to increase SMN levels. We found that antisense oligonucleotides (ASOs) complementary to the 5' end of SMN2 increase SMN mRNA and protein levels and that this effect is due to inhibition of SMN2 mRNA decay. Moreover, use of the 5' UTR ASO in combination with a splice-switching oligonucleotide (SSO) increases SMN levels above those attained with the SSO alone. Our results add to the current understanding of SMN regulation and point toward a new therapeutic target for SMA.
Collapse
|
24
|
Ji C, Bader J, Ramanathan P, Hennlein L, Meissner F, Jablonka S, Mann M, Fischer U, Sendtner M, Briese M. Interaction of 7SK with the Smn complex modulates snRNP production. Nat Commun 2021; 12:1278. [PMID: 33627647 PMCID: PMC7904863 DOI: 10.1038/s41467-021-21529-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/29/2021] [Indexed: 11/09/2022] Open
Abstract
Gene expression requires tight coordination of the molecular machineries that mediate transcription and splicing. While the interplay between transcription kinetics and spliceosome fidelity has been investigated before, less is known about mechanisms regulating the assembly of the spliceosomal machinery in response to transcription changes. Here, we report an association of the Smn complex, which mediates spliceosomal snRNP biogenesis, with the 7SK complex involved in transcriptional regulation. We found that Smn interacts with the 7SK core components Larp7 and Mepce and specifically associates with 7SK subcomplexes containing hnRNP R. The association between Smn and 7SK complexes is enhanced upon transcriptional inhibition leading to reduced production of snRNPs. Taken together, our findings reveal a functional association of Smn and 7SK complexes that is governed by global changes in transcription. Thus, in addition to its canonical nuclear role in transcriptional regulation, 7SK has cytosolic functions in fine-tuning spliceosome production according to transcriptional demand. The noncoding RNA 7SK controls the transcription of mRNAs. Here, the authors show that the 7SK complex interacts with the Smn complex, suggesting crosstalk between transcription and snRNP assembly.
Collapse
Affiliation(s)
- Changhe Ji
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Jakob Bader
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Pradhipa Ramanathan
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Felix Meissner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany.,Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany.,Department for Systems Immunology & Proteomics, Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn, Germany
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany.,NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| |
Collapse
|
25
|
In Search of a Cure: The Development of Therapeutics to Alter the Progression of Spinal Muscular Atrophy. Brain Sci 2021; 11:brainsci11020194. [PMID: 33562482 PMCID: PMC7915832 DOI: 10.3390/brainsci11020194] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
Until the recent development of disease-modifying therapeutics, spinal muscular atrophy (SMA) was considered a devastating neuromuscular disease with a poor prognosis for most affected individuals. Symptoms generally present during early childhood and manifest as muscle weakness and progressive paralysis, severely compromising the affected individual’s quality of life, independence, and lifespan. SMA is most commonly caused by the inheritance of homozygously deleted SMN1 alleles with retention of one or more copies of a paralog gene, SMN2, which inversely correlates with disease severity. The recent advent and use of genetically targeted therapies have transformed SMA into a prototype for monogenic disease treatment in the era of genetic medicine. Many SMA-affected individuals receiving these therapies achieve traditionally unobtainable motor milestones and survival rates as medicines drastically alter the natural progression of this disease. This review discusses historical SMA progression and underlying disease mechanisms, highlights advances made in therapeutic research, clinical trials, and FDA-approved medicines, and discusses possible second-generation and complementary medicines as well as optimal temporal intervention windows in order to optimize motor function and improve quality of life for all SMA-affected individuals.
Collapse
|
26
|
Lu JX, Wang Y, Zhang YJ, Shen MF, Li HY, Yu ZQ, Chen G. Axonal mRNA localization and local translation in neurodegenerative disease. Neural Regen Res 2021; 16:1950-1957. [PMID: 33642365 PMCID: PMC8343310 DOI: 10.4103/1673-5374.308074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The regulation of mRNA localization and local translation play vital roles in the maintenance of cellular structure and function. Many human neurodegenerative diseases, such as fragile X syndrome, amyotrophic lateral sclerosis, Alzheimer's disease, and spinal muscular atrophy, have been characterized by pathological changes in neuronal axons, including abnormal mRNA translation, the loss of protein expression, or abnormal axon transport. Moreover, the same protein and mRNA molecules have been associated with variable functions in different diseases due to differences in their interaction networks. In this review, we briefly examine fragile X syndrome, amyotrophic lateral sclerosis, Alzheimer's disease, and spinal muscular atrophy, with a focus on disease pathogenesis with regard to local mRNA translation and axon transport, suggesting possible treatment directions.
Collapse
Affiliation(s)
- Jin-Xin Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Yang Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province; Department of Neurosurgery, The First Affiliated Hospital of University of Science and Technology of China, Hefei, Anhui Province, China
| | - Yi-Jie Zhang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Mei-Fen Shen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Hai-Ying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Zheng-Quan Yu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| |
Collapse
|
27
|
Chen TH. Circulating microRNAs as potential biomarkers and therapeutic targets in spinal muscular atrophy. Ther Adv Neurol Disord 2020; 13:1756286420979954. [PMID: 33488772 PMCID: PMC7768327 DOI: 10.1177/1756286420979954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022] Open
Abstract
Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is a neurodegenerative disease characterized by the selective loss of particular groups of motor neurons (MNs) in the anterior horn of the spinal cord with progressive muscle wasting. SMA is caused by a deficiency of the survival motor neuron (SMN) protein due to a homozygous deletion or mutation of the SMN1 gene. However, the molecular mechanisms whereby the SMN complex regulates MN functions are not fully elucidated. Emerging studies on SMA pathogenesis have turned the attention of researchers to RNA metabolism, given that increasingly identified SMN-associated modifiers are involved in both coding and non-coding RNA (ncRNA) processing. Among various ncRNAs, microRNAs (miRNAs) are the most studied in terms of regulation of posttranscriptional gene expression. Recently, the discovery that miRNAs are critical to MN function and survival led to the study of dysregulated miRNAs in SMA pathogenesis. Circulating miRNAs have drawn attention as a readily available biomarker due to their property of being clinically detectable in numerous human biofluids through non-invasive approaches. As there are recent promising findings from novel miRNA-based medicines, this article presents an extensive review of the most up-to-date studies connecting specific miRNAs to SMA pathogenesis and the potential applications of miRNAs as biomarkers and therapeutic targets for SMA.
Collapse
Affiliation(s)
- Tai-Heng Chen
- Department of Pediatrics, Division of Pediatric Emergency, Kaohsiung Medical University Hospital, School of Post-Baccalaureate Medicine, College of Medicine, Kaohsiung Medical University, No. 100, Tzyou 1st Road, Kaohsiung 80708, Taiwan
| |
Collapse
|
28
|
Jutzi D, Campagne S, Schmidt R, Reber S, Mechtersheimer J, Gypas F, Schweingruber C, Colombo M, von Schroetter C, Loughlin FE, Devoy A, Hedlund E, Zavolan M, Allain FHT, Ruepp MD. Aberrant interaction of FUS with the U1 snRNA provides a molecular mechanism of FUS induced amyotrophic lateral sclerosis. Nat Commun 2020; 11:6341. [PMID: 33311468 PMCID: PMC7733473 DOI: 10.1038/s41467-020-20191-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/13/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the RNA-binding protein Fused in Sarcoma (FUS) cause early-onset amyotrophic lateral sclerosis (ALS). However, a detailed understanding of central RNA targets of FUS and their implications for disease remain elusive. Here, we use a unique blend of crosslinking and immunoprecipitation (CLIP) and NMR spectroscopy to identify and characterise physiological and pathological RNA targets of FUS. We find that U1 snRNA is the primary RNA target of FUS via its interaction with stem-loop 3 and provide atomic details of this RNA-mediated mode of interaction with the U1 snRNP. Furthermore, we show that ALS-associated FUS aberrantly contacts U1 snRNA at the Sm site with its zinc finger and traps snRNP biogenesis intermediates in human and murine motor neurons. Altogether, we present molecular insights into a FUS toxic gain-of-function involving direct and aberrant RNA-binding and strengthen the link between two motor neuron diseases, ALS and spinal muscular atrophy (SMA).
Collapse
Affiliation(s)
- Daniel Jutzi
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Sébastien Campagne
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Ralf Schmidt
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Stefan Reber
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Jonas Mechtersheimer
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Foivos Gypas
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, CH-4058, Basel, Switzerland
| | | | - Martino Colombo
- Celgene Institute of Translational Research (CITRE), 41092, Seville, Spain
| | - Christine von Schroetter
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Fionna E Loughlin
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Anny Devoy
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Eva Hedlund
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Mihaela Zavolan
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland.
| | - Marc-David Ruepp
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK.
| |
Collapse
|
29
|
Defective minor spliceosomes induce SMA-associated phenotypes through sensitive intron-containing neural genes in Drosophila. Nat Commun 2020; 11:5608. [PMID: 33154379 PMCID: PMC7644725 DOI: 10.1038/s41467-020-19451-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 10/13/2020] [Indexed: 01/31/2023] Open
Abstract
The minor spliceosome is evolutionarily conserved in higher eukaryotes, but its biological significance remains poorly understood. Here, by precise CRISPR/Cas9-mediated disruption of the U12 and U6atac snRNAs, we report that a defective minor spliceosome is responsible for spinal muscular atrophy (SMA) associated phenotypes in Drosophila. Using a newly developed bioinformatic approach, we identified a large set of minor spliceosome-sensitive splicing events and demonstrate that three sensitive intron-containing neural genes, Pcyt2, Zmynd10, and Fas3, directly contribute to disease development as evidenced by the ability of their cDNAs to rescue the SMA-associated phenotypes in muscle development, neuromuscular junctions, and locomotion. Interestingly, many splice sites in sensitive introns are recognizable by both minor and major spliceosomes, suggesting a new mechanism of splicing regulation through competition between minor and major spliceosomes. These findings reveal a vital contribution of the minor spliceosome to SMA and to regulated splicing in animals.
Collapse
|
30
|
Rademacher S, Detering NT, Schüning T, Lindner R, Santonicola P, Wefel IM, Dehus J, Walter LM, Brinkmann H, Niewienda A, Janek K, Varela MA, Bowerman M, Di Schiavi E, Claus P. A Single Amino Acid Residue Regulates PTEN-Binding and Stability of the Spinal Muscular Atrophy Protein SMN. Cells 2020; 9:cells9112405. [PMID: 33153033 PMCID: PMC7692393 DOI: 10.3390/cells9112405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/23/2020] [Accepted: 10/27/2020] [Indexed: 11/16/2022] Open
Abstract
Spinal Muscular Atrophy (SMA) is a neuromuscular disease caused by decreased levels of the survival of motoneuron (SMN) protein. Post-translational mechanisms for regulation of its stability are still elusive. Thus, we aimed to identify regulatory phosphorylation sites that modulate function and stability. Our results show that SMN residues S290 and S292 are phosphorylated, of which SMN pS290 has a detrimental effect on protein stability and nuclear localization. Furthermore, we propose that phosphatase and tensin homolog (PTEN), a novel phosphatase for SMN, counteracts this effect. In light of recent advancements in SMA therapies, a significant need for additional approaches has become apparent. Our study demonstrates S290 as a novel molecular target site to increase the stability of SMN. Characterization of relevant kinases and phosphatases provides not only a new understanding of SMN function, but also constitutes a novel strategy for combinatorial therapeutic approaches to increase the level of SMN in SMA.
Collapse
Affiliation(s)
- Sebastian Rademacher
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
| | - Nora T. Detering
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
- Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Tobias Schüning
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
- Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Robert Lindner
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
| | - Pamela Santonicola
- Institute of Biosciences and Bioresources, National Research Council of Italy, 80131 Naples, Italy; (P.S.); (E.D.S.)
| | - Inga-Maria Wefel
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
| | - Janina Dehus
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
| | - Lisa M. Walter
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
- Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
| | - Hella Brinkmann
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
| | - Agathe Niewienda
- Shared Facility for Mass Spectrometry, Institute of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; (A.N.); (K.J.)
| | - Katharina Janek
- Shared Facility for Mass Spectrometry, Institute of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; (A.N.); (K.J.)
| | - Miguel A. Varela
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; (M.A.V.); (M.B.)
- Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Melissa Bowerman
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; (M.A.V.); (M.B.)
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Elia Di Schiavi
- Institute of Biosciences and Bioresources, National Research Council of Italy, 80131 Naples, Italy; (P.S.); (E.D.S.)
| | - Peter Claus
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, 30625 Hannover, Germany; (S.R.); (N.T.D.); (T.S.); (R.L.); (I.-M.W.); (J.D.); (L.M.W.); (H.B.)
- Center for Systems Neuroscience (ZSN), 30559 Hannover, Germany
- Correspondence:
| |
Collapse
|
31
|
Abstract
RNA-binding proteins are a critical group of multifunctional proteins that precisely regulate all aspects of gene expression, from alternative splicing to mRNA trafficking, stability, and translation. Converging evidence highlights aberrant RNA metabolism as a common pathogenic mechanism in several neurodevelopmental and neurodegenerative diseases. However, dysregulation of disease-linked RNA-binding proteins results in widespread, often tissue-specific and/or pleiotropic effects on the transcriptome, making it challenging to determine the underlying cellular and molecular mechanisms that contribute to disease pathogenesis. Understanding how splicing misregulation as well as alterations of mRNA stability and localization impact the activity and function of neuronal proteins is fundamental to addressing neurodevelopmental defects and synaptic dysfunction in disease. Here we highlight recent exciting studies that use high-throughput transcriptomic analysis and advanced genetic, cell biological, and imaging approaches to dissect the role of disease-linked RNA-binding proteins on different RNA processing steps. We focus specifically on efforts to elucidate the functional consequences of aberrant RNA processing on neuronal morphology, synaptic activity and plasticity in development and disease. We also consider new areas of investigation that will elucidate the molecular mechanisms RNA-binding proteins use to achieve spatiotemporal control of gene expression for neuronal homeostasis and plasticity.
Collapse
Affiliation(s)
- Shavanie Prashad
- Department of Pathology, Yale University School of Medicine, Yale University, New Haven, CT, USA.,Experimental Pathology Graduate Group, Yale University School of Medicine, Yale University, New Haven, CT, USA
| | - Pallavi P Gopal
- Department of Pathology, Yale University School of Medicine, Yale University, New Haven, CT, USA.,Experimental Pathology Graduate Group, Yale University School of Medicine, Yale University, New Haven, CT, USA.,Yale Center for RNA Science and Medicine, Yale University School of Medicine, Yale University, New Haven, CT, USA
| |
Collapse
|
32
|
Adami R, Bottai D. Spinal Muscular Atrophy Modeling and Treatment Advances by Induced Pluripotent Stem Cells Studies. Stem Cell Rev Rep 2020; 15:795-813. [PMID: 31863335 DOI: 10.1007/s12015-019-09910-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Spinal Muscular Atrophy (SMA) is a neurodegenerative disease characterized by specific and predominantly lower motor neuron (MN) loss. SMA is the main reason for infant death, while about one in 40 children born is a healthy carrier. SMA is caused by decreased levels of production of a ubiquitously expressed gene: the survival motor neuron (SMN). All SMA patients present mutations of the telomeric SMN1 gene, but many copies of a centromeric, partially functional paralog gene, SMN2, can somewhat compensate for the SMN1 deficiency, scaling inversely with phenotypic harshness. Because the study of neural tissue in and from patients presents too many challenges and is very often not feasible; the use of animal models, such as the mouse, had a pivotal impact in our understanding of SMA pathology but could not portray totally satisfactorily the elaborate regulatory mechanisms that are present in higher animals, particularly in humans. And while recent therapeutic achievements have been substantial, especially for very young infants, some issues should be considered for the treatment of older patients. An alternative way to study SMA, and other neurological pathologies, is the use of induced pluripotent stem cells (iPSCs) derived from patients. In this work, we will present a wide analysis of the uses of iPSCs in SMA pathology, starting from basic science to their possible roles as therapeutic tools.
Collapse
Affiliation(s)
- Raffaella Adami
- Department of Health Sciences, University of Milan, via A. di Rudinì 8, 20142, Milan, Italy
| | - Daniele Bottai
- Department of Health Sciences, University of Milan, via A. di Rudinì 8, 20142, Milan, Italy.
| |
Collapse
|
33
|
Osman EY, Van Alstyne M, Yen PF, Lotti F, Feng Z, Ling KK, Ko CP, Pellizzoni L, Lorson CL. Minor snRNA gene delivery improves the loss of proprioceptive synapses on SMA motor neurons. JCI Insight 2020; 5:130574. [PMID: 32516136 DOI: 10.1172/jci.insight.130574] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 05/13/2020] [Indexed: 12/17/2022] Open
Abstract
Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. SMN has key functions in multiple RNA pathways, including the biogenesis of small nuclear ribonucleoproteins that are essential components of both major (U2-dependent) and minor (U12-dependent) spliceosomes. Here we investigated the specific contribution of U12 splicing dysfunction to SMA pathology through selective restoration of this RNA pathway in mouse models of varying phenotypic severity. We show that virus-mediated delivery of minor snRNA genes specifically improves select U12 splicing defects induced by SMN deficiency in cultured mammalian cells, as well as in the spinal cord and dorsal root ganglia of SMA mice without increasing SMN expression. This approach resulted in a moderate amelioration of several parameters of the disease phenotype in SMA mice, including survival, weight gain, and motor function. Importantly, minor snRNA gene delivery improved aberrant splicing of the U12 intron-containing gene Stasimon and rescued the severe loss of proprioceptive sensory synapses on SMA motor neurons, which are early signatures of motor circuit dysfunction in mouse models. Taken together, these findings establish the direct contribution of U12 splicing dysfunction to synaptic deafferentation and motor circuit pathology in SMA.
Collapse
Affiliation(s)
- Erkan Y Osman
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Meaghan Van Alstyne
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Pei-Fen Yen
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Francesco Lotti
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Zhihua Feng
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Karen Ky Ling
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Livio Pellizzoni
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Christian L Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| |
Collapse
|
34
|
Laaref AM, Manchon L, Bareche Y, Lapasset L, Tazi J. The core spliceosomal factor U2AF1 controls cell-fate determination via the modulation of transcriptional networks. RNA Biol 2020; 17:857-871. [PMID: 32150510 PMCID: PMC7549707 DOI: 10.1080/15476286.2020.1733800] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/10/2020] [Indexed: 12/16/2022] Open
Abstract
Alternative splicing (AS) plays a central role during cell-fate determination. However, how the core spliceosomal factors (CSFs) are involved in this process is poorly understood. Here, we report the down-regulation of the U2AF1 CSF during stem cell differentiation. To investigate its function in stemness and differentiation, we downregulated U2AF1 in human induced pluripotent stem cells (hiPSCs), using an inducible-shRNA system, to the level found in differentiated ectodermal, mesodermal and endodermal cells. RNA sequencing and computational analysis reveal that U2AF1 down-regulation modulates the expression of development-regulating genes and regulates transcriptional networks involved in cell-fate determination. Furthermore, U2AF1 down-regulation induces a switch in the AS of transcription factors (TFs) required to establish specific cell lineages, and favours the splicing of a differentiated cell-specific isoform of DNMT3B. Our results showed that the differential expression of the core spliceosomal factor U2AF1, between stem cells and the precursors of the three germ layers regulates a cell-type-specific alternative splicing programme and a transcriptional network involved in cell-fate determination via the modulation of gene expression and alternative splicing of transcription regulators.
Collapse
Affiliation(s)
| | | | - Yacine Bareche
- IGMM, CNRS, University of Montpellier, Montpellier, France
- Breast Cancer Translational Research Laboratory, J. C. Heuson, Institut Jules Bordet, Université Libre De Bruxelles, Brussels, Belgium
| | - Laure Lapasset
- IGMM, CNRS, University of Montpellier, Montpellier, France
- VP research, CNRS, University of Montpellier, Montpellier, France
| | - Jamal Tazi
- IGMM, CNRS, University of Montpellier, Montpellier, France
- Lead Contact
| |
Collapse
|
35
|
Abstract
Objectives: The beneficial effects of many substances have been discovered because of regular dietary consumption. This is also the case with curcumin, whose effects have been known for more than 4,000 years in Eastern countries such as China and India. A curcumin-rich diet has been known to counteract many human diseases, including cancer and diabetes, and has been shown to reduce inflammation. The effect of a curcumin treatment for neurological diseases, such as spinal muscular atrophy; Alzheimer's disease; Parkinson's disease; amyotrophic lateral sclerosis; multiple sclerosis; and others, has only recently been brought to the attention of researchers and the wider population.Methods: In this paper, we summarise the studies on this natural product, from its isolation two centuries ago to its characterisation a century later.Results: We describe its role in the treatment of neurological diseases, including its cellular and common molecular mechanisms, and we report on the clinical trials of curcumin with healthy people and patients.Discussion: Commenting on the different approaches adopted by the efforts made to increase its bioavailability.
Collapse
Affiliation(s)
- Raffaella Adami
- Department of Health Sciences, University of Milan, Milan, Italy
| | - Daniele Bottai
- Department of Health Sciences, University of Milan, Milan, Italy
| |
Collapse
|
36
|
New and Developing Therapies in Spinal Muscular Atrophy: From Genotype to Phenotype to Treatment and Where Do We Stand? Int J Mol Sci 2020; 21:ijms21093297. [PMID: 32392694 PMCID: PMC7246502 DOI: 10.3390/ijms21093297] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a congenital neuromuscular disorder characterized by motor neuron loss, resulting in progressive weakness. SMA is notable in the health care community because it accounts for the most common cause of infant death resulting from a genetic defect. SMA is caused by low levels of the survival motor neuron protein (SMN) resulting from SMN1 gene mutations or deletions. However, patients always harbor various copies of SMN2, an almost identical but functionally deficient copy of the gene. A genotype–phenotype correlation suggests that SMN2 is a potent disease modifier for SMA, which also represents the primary target for potential therapies. Increasing comprehension of SMA pathophysiology, including the characterization of SMN1 and SMN2 genes and SMN protein functions, has led to the development of multiple therapeutic approaches. Until the end of 2016, no cure was available for SMA, and management consisted of supportive measures. Two breakthrough SMN-targeted treatments, either using antisense oligonucleotides (ASOs) or virus-mediated gene therapy, have recently been approved. These two novel therapeutics have a common objective: to increase the production of SMN protein in MNs and thereby improve motor function and survival. However, neither therapy currently provides a complete cure. Treating patients with SMA brings new responsibilities and unique dilemmas. As SMA is such a devastating disease, it is reasonable to assume that a unique therapeutic solution may not be sufficient. Current approaches under clinical investigation differ in administration routes, frequency of dosing, intrathecal versus systemic delivery, and mechanisms of action. Besides, emerging clinical trials evaluating the efficacy of either SMN-dependent or SMN-independent approaches are ongoing. This review aims to address the different knowledge gaps between genotype, phenotypes, and potential therapeutics.
Collapse
|
37
|
Therapeutic potential of stem cells for treatment of neurodegenerative diseases. Biotechnol Lett 2020; 42:1073-1101. [DOI: 10.1007/s10529-020-02886-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 04/05/2020] [Indexed: 12/13/2022]
|
38
|
Sapaly D, Delers P, Coridon J, Salman B, Letourneur F, Dumont F, Lefebvre S. The Small-Molecule Flunarizine in Spinal Muscular Atrophy Patient Fibroblasts Impacts on the Gemin Components of the SMN Complex and TDP43, an RNA-Binding Protein Relevant to Motor Neuron Diseases. Front Mol Biosci 2020; 7:55. [PMID: 32363199 PMCID: PMC7181958 DOI: 10.3389/fmolb.2020.00055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/18/2020] [Indexed: 01/01/2023] Open
Abstract
The motor neurodegenerative disease spinal muscular atrophy (SMA) is caused by alterations of the survival motor neuron 1 (SMN1) gene involved in RNA metabolism. Although the disease mechanisms are not completely elucidated, SMN protein deficiency leads to abnormal small nuclear ribonucleoproteins (snRNPs) assembly responsible for widespread splicing defects. SMN protein localizes in nuclear bodies that are lost in SMA and adult onset amyotrophic lateral sclerosis (ALS) patient cells harboring TDP-43 or FUS/TLS mutations. We previously reported that flunarizine recruits SMN into nuclear bodies and improves the phenotype of an SMA mouse model. However, the precise mode of action remains elusive. Here, a marked reduction of the integral components of the SMN complex is observed in severe SMA patient fibroblast cells. We show that flunarizine increases the protein levels of a subset of components of the SMN-Gemins complex, Gemins2-4, and markedly reduces the RNA and protein levels of the pro-oxydant thioredoxin-interacting protein (TXNIP) encoded by an mRNA target of Gemin5. We further show that SMN deficiency causes a dissociation of the localization of the SMN complex components from the same nuclear bodies. The accumulation of TDP-43 in SMN-positive nuclear bodies is also perturbed in SMA cells. Notably, TDP-43 is found to co-localize with SMN in nuclear bodies of flunarizine-treated SMA cells. Our findings indicate that flunarizine reverses cellular changes caused by SMN deficiency in SMA cells and further support the view of a common pathway in RNA metabolism underlying infantile and adult motor neuron diseases.
Collapse
Affiliation(s)
- Delphine Sapaly
- INSERM UMR-S 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Campus Saint-Germain-des-Prés, Université de Paris, Paris, France
| | - Perrine Delers
- INSERM UMR-S 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Campus Saint-Germain-des-Prés, Université de Paris, Paris, France
| | - Jennifer Coridon
- BioMedTech Facilities INSERM US36 - CNRS UMS 2009, Campus Saint-Germain-des-Prés, Université de Paris, Paris, France
| | - Badih Salman
- INSERM UMR-S 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Campus Saint-Germain-des-Prés, Université de Paris, Paris, France
| | | | - Florent Dumont
- Genom'ic Platform, INSERM U1016, Institut Cochin, Paris, France
| | - Suzie Lefebvre
- INSERM UMR-S 1124, Toxicité Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Campus Saint-Germain-des-Prés, Université de Paris, Paris, France
| |
Collapse
|
39
|
Chaudhuri A, Das S, Das B. Localization elements and zip codes in the intracellular transport and localization of messenger RNAs in Saccharomyces cerevisiae. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1591. [PMID: 32101377 DOI: 10.1002/wrna.1591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
Intracellular trafficking and localization of mRNAs provide a mechanism of regulation of expression of genes with excellent spatial control. mRNA localization followed by localized translation appears to be a mechanism of targeted protein sorting to a specific cell-compartment, which is linked to the establishment of cell polarity, cell asymmetry, embryonic axis determination, and neuronal plasticity in metazoans. However, the complexity of the mechanism and the components of mRNA localization in higher organisms prompted the use of the unicellular organism Saccharomyces cerevisiae as a simplified model organism to study this vital process. Current knowledge indicates that a variety of mRNAs are asymmetrically and selectively localized to the tip of the bud of the daughter cells, to the vicinity of endoplasmic reticulum, mitochondria, and nucleus in this organism, which are connected to diverse cellular processes. Interestingly, specific cis-acting RNA localization elements (LEs) or RNA zip codes play a crucial role in the localization and trafficking of these localized mRNAs by providing critical binding sites for the specific RNA-binding proteins (RBPs). In this review, we present a comprehensive account of mRNA localization in S. cerevisiae, various types of localization elements influencing the mRNA localization, and the RBPs, which bind to these LEs to implement a number of vital physiological processes. Finally, we emphasize the significance of this process by highlighting their connection to several neuropathological disorders and cancers. This article is categorized under: RNA Export and Localization > RNA Localization.
Collapse
Affiliation(s)
- Anusha Chaudhuri
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Subhadeep Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| |
Collapse
|
40
|
Wirth B, Karakaya M, Kye MJ, Mendoza-Ferreira N. Twenty-Five Years of Spinal Muscular Atrophy Research: From Phenotype to Genotype to Therapy, and What Comes Next. Annu Rev Genomics Hum Genet 2020; 21:231-261. [PMID: 32004094 DOI: 10.1146/annurev-genom-102319-103602] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Twenty-five years ago, the underlying genetic cause for one of the most common and devastating inherited diseases in humans, spinal muscular atrophy (SMA), was identified. Homozygous deletions or, rarely, subtle mutations of SMN1 cause SMA, and the copy number of the nearly identical copy gene SMN2 inversely correlates with disease severity. SMA has become a paradigm and a prime example of a monogenic neurological disorder that can be efficiently ameliorated or nearly cured by novel therapeutic strategies, such as antisense oligonucleotide or gene replacement therapy. These therapies enable infants to survive who might otherwise have died before the age of two and allow individuals who have never been able to sit or walk to do both. The major milestones on the road to these therapies were to understand the genetic cause and splice regulation of SMN genes, the disease's phenotype-genotype variability, the function of the protein and the main affected cellular pathways and tissues, the disease's pathophysiology through research on animal models, the windows of opportunity for efficient treatment, and how and when to treat patients most effectively.This review aims to bridge our knowledge from phenotype to genotype to therapy, not only highlighting the significant advances so far but also speculating about the future of SMA screening and treatment.
Collapse
Affiliation(s)
- Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Mert Karakaya
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Min Jeong Kye
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Natalia Mendoza-Ferreira
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| |
Collapse
|
41
|
Antoine M, Patrick KL, Soret J, Duc P, Rage F, Cacciottolo R, Nissen KE, Cauchi RJ, Krogan NJ, Guthrie C, Gachet Y, Bordonné R. Splicing Defects of the Profilin Gene Alter Actin Dynamics in an S. pombe SMN Mutant. iScience 2019; 23:100809. [PMID: 31927482 PMCID: PMC6957872 DOI: 10.1016/j.isci.2019.100809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/13/2019] [Accepted: 12/23/2019] [Indexed: 12/18/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating motor neuron disorder caused by mutations in the survival motor neuron (SMN) gene. It remains unclear how SMN deficiency leads to the loss of motor neurons. By screening Schizosaccharomyces pombe, we found that the growth defect of an SMN mutant can be alleviated by deletion of the actin-capping protein subunit gene acp1+. We show that SMN mutated cells have splicing defects in the profilin gene, which thus directly hinder actin cytoskeleton homeostasis including endocytosis and cytokinesis. We conclude that deletion of acp1+ in an SMN mutant background compensates for actin cytoskeleton alterations by restoring redistribution of actin monomers between different types of cellular actin networks. Our data reveal a direct correlation between an impaired function of SMN in snRNP assembly and defects in actin dynamics. They also point to important common features in the pathogenic mechanism of SMA and ALS. Splicing defects in the profilin gene in an S. pombe SMN mutant SMN mutant contains excessively polymerized actin Altered actin dynamics in the SMN mutant hinders endocytosis and cytokinesis Deletion of the acp1 subunit restores actin dynamics in the SMN mutant
Collapse
Affiliation(s)
- Marie Antoine
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | | | - Johann Soret
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Pauline Duc
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Florence Rage
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Rebecca Cacciottolo
- Department of Physiology and Biochemistry, University of Malta, Msida, Malta
| | | | - Ruben J Cauchi
- Department of Physiology and Biochemistry, University of Malta, Msida, Malta
| | | | | | - Yannick Gachet
- Centre de Biologie Integrative, University of Toulouse, CNRS, Toulouse, France
| | - Rémy Bordonné
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France.
| |
Collapse
|
42
|
Chen TH, Chen JA. Multifaceted roles of microRNAs: From motor neuron generation in embryos to degeneration in spinal muscular atrophy. eLife 2019; 8:50848. [PMID: 31738166 PMCID: PMC6861003 DOI: 10.7554/elife.50848] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022] Open
Abstract
Two crucial questions in neuroscience are how neurons establish individual identity in the developing nervous system and why only specific neuron subtypes are vulnerable to neurodegenerative diseases. In the central nervous system, spinal motor neurons serve as one of the best-characterized cell types for addressing these two questions. In this review, we dissect these questions by evaluating the emerging role of regulatory microRNAs in motor neuron generation in developing embryos and their potential contributions to neurodegenerative diseases such as spinal muscular atrophy (SMA). Given recent promising results from novel microRNA-based medicines, we discuss the potential applications of microRNAs for clinical assessments of SMA disease progression and treatment.
Collapse
Affiliation(s)
- Tai-Heng Chen
- PhD Program in Translational Medicine, Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Academia Sinica, Kaohsiung, Taiwan.,Department of Pediatrics, Division of Pediatric Emergency, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jun-An Chen
- PhD Program in Translational Medicine, Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Academia Sinica, Kaohsiung, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
43
|
Nussbacher JK, Tabet R, Yeo GW, Lagier-Tourenne C. Disruption of RNA Metabolism in Neurological Diseases and Emerging Therapeutic Interventions. Neuron 2019; 102:294-320. [PMID: 30998900 DOI: 10.1016/j.neuron.2019.03.014] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 01/24/2019] [Accepted: 03/12/2019] [Indexed: 02/06/2023]
Abstract
RNA binding proteins are critical to the maintenance of the transcriptome via controlled regulation of RNA processing and transport. Alterations of these proteins impact multiple steps of the RNA life cycle resulting in various molecular phenotypes such as aberrant RNA splicing, transport, and stability. Disruption of RNA binding proteins and widespread RNA processing defects are increasingly recognized as critical determinants of neurological diseases. Here, we describe distinct mechanisms by which the homeostasis of RNA binding proteins is compromised in neurological disorders through their reduced expression level, increased propensity to aggregate or sequestration by abnormal RNAs. These mechanisms all converge toward altered neuronal function highlighting the susceptibility of neurons to deleterious changes in RNA expression and the central role of RNA binding proteins in preserving neuronal integrity. Emerging therapeutic approaches to mitigate or reverse alterations of RNA binding proteins in neurological diseases are discussed.
Collapse
Affiliation(s)
- Julia K Nussbacher
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA, USA
| | - Ricardos Tabet
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA, USA.
| | - Clotilde Lagier-Tourenne
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA.
| |
Collapse
|
44
|
AAV9 Vector: a Novel modality in gene therapy for spinal muscular atrophy. Gene Ther 2019; 26:287-295. [PMID: 31243392 DOI: 10.1038/s41434-019-0085-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 05/03/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022]
Abstract
Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is characterized by the deterioration of alpha motor neurons in the brainstem and spinal cord. Currently, there is no cure for SMA, which calls for an urgent need to explore affordable and effective therapies and to maximize patients' independence and quality of life. Adeno-associated virus (AAV) vector, one of the most promising and well-investigated vehicles for delivering transgenes, is a compelling candidate for gene therapy. Some of the hallmarks of AAVs are their nonpathogenicity, inability to incur an immune response, potential to achieve robust transgene expression, and varied tropism for several tissues of the body. Recently, these features were harnessed in a clinical trial conducted by AveXis in SMA patients, where AAV9 was employed as a vehicle for one-time administration of the SMN gene, the causative gene in SMA. The trial demonstrated remarkable improvements in motor milestones and rates of survival in the patients. This review focuses on the advent of SMA gene therapy and summarizes different preclinical studies that were conducted leading up to the AAV9-SMA trial in SMA patients.
Collapse
|
45
|
Watson CN, Belli A, Di Pietro V. Small Non-coding RNAs: New Class of Biomarkers and Potential Therapeutic Targets in Neurodegenerative Disease. Front Genet 2019; 10:364. [PMID: 31080456 PMCID: PMC6497742 DOI: 10.3389/fgene.2019.00364] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/05/2019] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative diseases (NDs) are becoming increasingly prevalent in the world, with an aging population. In the last few decades, due to the devastating nature of these diseases, the research of biomarkers has become crucial to enable adequate treatments and to monitor the progress of disease. Currently, gene mutations, CSF and blood protein markers together with the neuroimaging techniques are the most used diagnostic approaches. However, despite the efforts in the research, conflicting data still exist, highlighting the need to explore new classes of biomarkers, particularly at early stages. Small non-coding RNAs (MicroRNA, Small nuclear RNA, Small nucleolar RNA, tRNA derived small RNA and Piwi-interacting RNA) can be considered a "relatively" new class of molecule that have already proved to be differentially regulated in many NDs, hence they represent a new potential class of biomarkers to be explored. In addition, understanding their involvement in disease development could depict the underlying pathogenesis of particular NDs, so novel treatment methods that act earlier in disease progression can be developed. This review aims to describe the involvement of small non-coding RNAs as biomarkers of NDs and their potential role in future clinical applications.
Collapse
Affiliation(s)
- Callum N. Watson
- Neuroscience and Ophthalmology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Antonio Belli
- Neuroscience and Ophthalmology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Valentina Di Pietro
- Neuroscience and Ophthalmology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana–Champaign, Urbana, IL, United States
| |
Collapse
|
46
|
Walters R, Manion J, Neely GG. Dissecting Motor Neuron Disease With Drosophila melanogaster. Front Neurosci 2019; 13:331. [PMID: 31031583 PMCID: PMC6473072 DOI: 10.3389/fnins.2019.00331] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/21/2019] [Indexed: 12/13/2022] Open
Abstract
Motor Neuron Disease (MND) typically affects patients during the later stages of life, and thus, MND is having an increasingly devastating impact on diagnosed individuals, their families and society. The umbrella term MND refers to diseases which cause the progressive loss of upper and/or lower motor neurons and a subsequent decrease in motor ability such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). The study of these diseases is complex and has recently involved the use of genome-wide association studies (GWAS). However, in the case of MND, it has been difficult to identify the complex genetics involved in subtypes, and functional investigation of new candidate disease genes is warranted. Drosophila is a powerful model for addressing these complex diseases. The UAS/Gal4/Gal80 system allows for the upregulation of Drosophila genes, the “knockdown” of genes and the ectopic expression of human genes or mutations in a tissue-specific manner; often resulting in Drosophila models which exhibit typical MND disease pathologies. These can then be further interrogated to identify disease-modifying genes or mutations and disease pathways. This review will discuss two common MNDs and the current Drosophila models which are being used to research their genetic basis and the different pathologies of MND.
Collapse
Affiliation(s)
- Rachel Walters
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - John Manion
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - G Gregory Neely
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
47
|
Nik S, Bowman TV. Splicing and neurodegeneration: Insights and mechanisms. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1532. [PMID: 30895702 DOI: 10.1002/wrna.1532] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022]
Abstract
Splicing is the global cellular process whereby intervening sequences (introns) in precursor messenger RNA (pre-mRNA) are removed and expressed regions (exons) are ligated together, resulting in a mature mRNA transcript that is exported and translated in the cytoplasm. The tightly regulated splicing cycle is also flexible allowing for the inclusion or exclusion of some sequences depending on the specific cellular context. Alternative splicing allows for the generation of many transcripts from a single gene, thereby expanding the proteome. Although all cells require the function of the spliceosome, neurons are highly sensitive to splicing perturbations with numerous neurological diseases linked to splicing defects. The sensitivity of neurons to splicing alterations is largely due to the complex neuronal cell types and functions in the nervous system that require specific splice isoforms to maintain cellular homeostasis. In the past several years, the relationship between RNA splicing and the nervous system has been the source of significant investigation. Here, we review the current knowledge on RNA splicing in neurobiology and discuss its potential role and impact in neurodegenerative diseases. We will examine the impact of alternative splicing and the role of splicing regulatory proteins on neurodegeneration, highlighting novel animal models including mouse and zebrafish. We will also examine emerging technologies and therapeutic interventions that aim to "drug" the spliceosome. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Development.
Collapse
Affiliation(s)
- Sara Nik
- Department of Developmental and Molecular Biology and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Teresa V Bowman
- Department of Developmental and Molecular Biology, Department of Medicine (Oncology), and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
48
|
FTO controls reversible m 6Am RNA methylation during snRNA biogenesis. Nat Chem Biol 2019; 15:340-347. [PMID: 30778204 DOI: 10.1038/s41589-019-0231-8] [Citation(s) in RCA: 187] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 01/12/2019] [Indexed: 01/31/2023]
Abstract
Small nuclear RNAs (snRNAs) are core spliceosome components and mediate pre-mRNA splicing. Here we show that snRNAs contain a regulated and reversible nucleotide modification causing them to exist as two different methyl isoforms, m1 and m2, reflecting the methylation state of the adenosine adjacent to the snRNA cap. We find that snRNA biogenesis involves the formation of an initial m1 isoform with a single-methylated adenosine (2'-O-methyladenosine, Am), which is then converted to a dimethylated m2 isoform (N6,2'-O-dimethyladenosine, m6Am). The relative m1 and m2 isoform levels are determined by the RNA demethylase FTO, which selectively demethylates the m2 isoform. We show FTO is inhibited by the oncometabolite D-2-hydroxyglutarate, resulting in increased m2-snRNA levels. Furthermore, cells that exhibit high m2-snRNA levels show altered patterns of alternative splicing. Together, these data reveal that FTO controls a previously unknown central step of snRNA processing involving reversible methylation, and suggest that epitranscriptomic information in snRNA may influence mRNA splicing.
Collapse
|
49
|
Venters CC, Oh JM, Di C, So BR, Dreyfuss G. U1 snRNP Telescripting: Suppression of Premature Transcription Termination in Introns as a New Layer of Gene Regulation. Cold Spring Harb Perspect Biol 2019; 11:11/2/a032235. [PMID: 30709878 DOI: 10.1101/cshperspect.a032235] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent observations showed that nascent RNA polymerase II transcripts, pre-mRNAs, and noncoding RNAs are highly susceptible to premature 3'-end cleavage and polyadenylation (PCPA) from numerous intronic cryptic polyadenylation signals (PASs). The importance of this in gene regulation was not previously appreciated as PASs, despite their prevalence, were thought to be active in terminal exons at gene ends. Unexpectedly, antisense oligonucleotide interference with U1 snRNA base-pairing to 5' splice sites, which is necessary for U1 snRNP's (U1) function in splicing, caused widespread PCPA in metazoans. This uncovered U1's PCPA suppression activity, termed telescripting, as crucial for full-length transcription in thousands of vertebrate genes, providing a general role in transcription elongation control. Progressive intron-size expansion in metazoan evolution greatly increased PCPA vulnerability and dependence on U1 telescripting. We describe how these observations unfolded and discuss U1 telescripting's role in shaping the transcriptome.
Collapse
Affiliation(s)
- Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| |
Collapse
|
50
|
Šoltić D, Bowerman M, Stock J, Shorrock HK, Gillingwater TH, Fuller HR. Multi-Study Proteomic and Bioinformatic Identification of Molecular Overlap between Amyotrophic Lateral Sclerosis (ALS) and Spinal Muscular Atrophy (SMA). Brain Sci 2018; 8:brainsci8120212. [PMID: 30518112 PMCID: PMC6315439 DOI: 10.3390/brainsci8120212] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 12/24/2022] Open
Abstract
Unravelling the complex molecular pathways responsible for motor neuron degeneration in amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) remains a persistent challenge. Interest is growing in the potential molecular similarities between these two diseases, with the hope of better understanding disease pathology for the guidance of therapeutic development. The aim of this study was to conduct a comparative analysis of published proteomic studies of ALS and SMA, seeking commonly dysregulated molecules to be prioritized as future therapeutic targets. Fifteen proteins were found to be differentially expressed in two or more proteomic studies of both ALS and SMA, and bioinformatics analysis identified over-representation of proteins known to associate in vesicles and molecular pathways, including metabolism of proteins and vesicle-mediated transport—both of which converge on endoplasmic reticulum (ER)-Golgi trafficking processes. Calreticulin, a calcium-binding chaperone found in the ER, was associated with both pathways and we independently confirm that its expression was decreased in spinal cords from SMA and increased in spinal cords from ALS mice. Together, these findings offer significant insights into potential common targets that may help to guide the development of new therapies for both diseases.
Collapse
Affiliation(s)
- Darija Šoltić
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (D.S.); (M.B.)
- Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Melissa Bowerman
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (D.S.); (M.B.)
- Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Joanne Stock
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (D.S.); (M.B.)
- Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
| | - Hannah K. Shorrock
- Biomedical Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh EH8 9AG, UK; (H.K.S.); (T.H.G.)
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9AG, UK
| | - Thomas H. Gillingwater
- Biomedical Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh EH8 9AG, UK; (H.K.S.); (T.H.G.)
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh EH8 9AG, UK
| | - Heidi R. Fuller
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (D.S.); (M.B.)
- Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 5BG, UK
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK
- Correspondence: ; Tel.: +44-169-140-4693; Fax: +44-169-140-4065
| |
Collapse
|