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Wang J, Zhang Y, Gao J, Feng G, Liu C, Li X, Li P, Liu Z, Lu F, Wang L, Li W, Zhou Q, Liu Y. Alternative splicing of CARM1 regulated by LincGET-guided paraspeckles biases the first cell fate in mammalian early embryos. Nat Struct Mol Biol 2024; 31:1341-1354. [PMID: 38658621 PMCID: PMC11402786 DOI: 10.1038/s41594-024-01292-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 03/25/2024] [Indexed: 04/26/2024]
Abstract
The heterogeneity of CARM1 controls first cell fate bias during early mouse development. However, how this heterogeneity is established is unknown. Here, we show that Carm1 mRNA is of a variety of specific exon-skipping splicing (ESS) isoforms in mouse two-cell to four-cell embryos that contribute to CARM1 heterogeneity. Disruption of paraspeckles promotes the ESS of Carm1 precursor mRNAs (pre-mRNAs). LincGET, but not Neat1, is required for paraspeckle assembly and inhibits the ESS of Carm1 pre-mRNAs in mouse two-cell to four-cell embryos. We further find that LincGET recruits paraspeckles to the Carm1 gene locus through HNRNPU. Interestingly, PCBP1 binds the Carm1 pre-mRNAs and promotes its ESS in the absence of LincGET. Finally, we find that the ESS seen in mouse two-cell to four-cell embryos decreases CARM1 protein levels and leads to trophectoderm fate bias. Our findings demonstrate that alternative splicing of CARM1 has an important role in first cell fate determination.
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Affiliation(s)
- Jiaqiang Wang
- College of Life Science, Northeast Agricultural University, Harbin, China.
| | - Yiwei Zhang
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Jiaze Gao
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Guihai Feng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xueke Li
- College of Life Science, Northeast Agricultural University, Harbin, China
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Li
- College of Life Science, Northeast Agricultural University, Harbin, China
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhonghua Liu
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Falong Lu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Leyun Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
| | - Yusheng Liu
- College of Life Science, Northeast Forestry University, Harbin, China.
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2
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Kadyan P, Singh L. Unraveling the mechanistic interplay of mediators orchestrating the neuroprotective potential of harmine. Pharmacol Rep 2024; 76:665-678. [PMID: 38758470 DOI: 10.1007/s43440-024-00602-8] [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: 02/18/2024] [Revised: 04/27/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024]
Abstract
Neurodegenerative diseases (NDDs) encompass a range of conditions characterized by the specific dysfunction and continual decline of neurons, glial cells, and neural networks within the brain and spinal cord. The majority of NDDs exhibit similar underlying causes, including oxidative stress, neuroinflammation, and malfunctioning of mitochondria. Elevated levels of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), alongside decreased expression of brain-derived neurotrophic factor (BDNF) and glutamate transporter subtype 1 (GLT-1), constitute significant factors contributing to the pathogenesis of NDDs. Additionally, the dual-specificity tyrosine phosphorylation-regulated kinase 1 A (DYRK1A) gene has emerged as a significant target for the treatment of NDDs at the preclinical level. It significantly contributes to developmental brain defects, early onset neurodegeneration, neuronal loss, and dementia in Down syndrome. Moreover, an impaired ubiquitin-proteosome system (UPS) also plays a pathological role in NDDs. Malfunctioning of UPS leads to abnormal protein buildup or aggregation of α-synuclein. α-Synuclein is a highly soluble unfolded protein that accumulates in Lewy bodies and Lewy neurites in Parkinson's disease and other synucleinopathies. Recent research highlights the promising potential of natural products in combating NDDs relative to conventional therapies. Alkaloids have emerged as promising candidates in the fight against NDDs. Harmine is a tricyclic β-carboline alkaloid (harmala alkaloid) with one indole nucleus and a six-membered pyrrole ring. It is extracted from Banisteria caapi and Peganum harmala L. and exhibits diverse pharmacological properties, encompassing neuroprotective, antioxidant, anti-inflammatory, antidepressant, etc. Harmine has been reported to mediate its neuroprotective via reducing the level of inflammatory mediators, NADPH oxidase, AChE, BChE and reactive oxygen species (ROS). Whereas, it has been observed to increase the levels of BDNF, GLT-1 and anti-oxidant enzymes, along with protein kinase-A (PKA)-mediated UPS activation. This review aims to discuss the mechanistic interplay of various mediators involved in the neuroprotective effect of harmine.
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Affiliation(s)
- Pankaj Kadyan
- University Institute of Pharma Sciences, Chandigarh University, Mohali, Punjab, India
| | - Lovedeep Singh
- University Institute of Pharma Sciences, Chandigarh University, Mohali, Punjab, India.
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3
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de Albuquerque ALA, Chadanowicz JK, Giudicelli GC, Staub ALP, Weber AC, Silva JMDS, Becker MM, Kowalski TW, Siebert M, Saute JAM. Serum myostatin as a candidate disease severity and progression biomarker of spinal muscular atrophy. Brain Commun 2024; 6:fcae062. [PMID: 38487549 PMCID: PMC10939446 DOI: 10.1093/braincomms/fcae062] [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: 07/28/2023] [Revised: 01/18/2024] [Accepted: 02/27/2024] [Indexed: 03/17/2024] Open
Abstract
The identification of biomarkers for spinal muscular atrophy is crucial for predicting disease progression, severity, and response to new disease-modifying therapies. This study aimed to investigate the role of serum levels of myostatin and follistatin as biomarkers for spinal muscular atrophy, considering muscle atrophy secondary to denervation as the main clinical manifestation of the disease. The study evaluated the differential gene expression of myostatin and follistatin in a lesional model of gastrocnemius denervation in mice, as well as in a meta-analysis of three datasets in transgenic mice models of spinal muscular atrophy, and in two studies involving humans with spinal muscular atrophy. Subsequently, a case-control study involving 27 spinal muscular atrophy patients and 27 controls was conducted, followed by a 12-month cohort study with 25 spinal muscular atrophy cases. Serum levels of myostatin and follistatin were analysed using enzyme-linked immunosorbent assay at a single centre in southern Brazil. Skeletal muscle gene expression of myostatin decreased and of follistatin increased following lesional muscle denervation in mice, consistent with findings in the spinal muscular atrophy transgenic mice meta-analysis and in the iliopsoas muscle of five patients with spinal muscular atrophy type 1. Median serum myostatin levels were significantly lower in spinal muscular atrophy patients (98 pg/mL; 5-157) compared to controls (412 pg/mL; 299-730) (P < 0.001). Lower myostatin levels were associated with greater disease severity based on clinician-rated outcomes (Rho = 0.493-0.812; P < 0.05). After 12 months, there was a further reduction in myostatin levels among spinal muscular atrophy cases (P = 0.021). Follistatin levels did not differ between cases and controls, and no significant changes were observed over time. The follistatin:myostatin ratio was significantly increased in spinal muscular atrophy subjects and inversely correlated with motor severity. Serum myostatin levels show promise as a novel biomarker for evaluating the severity and progression of spinal muscular atrophy. The decrease in myostatin levels and the subsequent favourable environment for muscle growth may be attributed to denervation caused by motor neuron dysfunction.
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Affiliation(s)
- Ana Letícia Amorim de Albuquerque
- Graduate Program in Medicine, Medical Sciences, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Júlia Kersting Chadanowicz
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Giovanna Câmara Giudicelli
- Bioinformatics core, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Graduate Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, Brazil
| | - Ana Lucia Portella Staub
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Arthur Carpeggiani Weber
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | | | | | - Thayne Woycinck Kowalski
- Bioinformatics core, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Graduate Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
| | - Marina Siebert
- Unit of Laboratorial Research, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre 90035-007, Brazil
- Graduate Program in Gastroenterology and Hepatology, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
| | - Jonas Alex Morales Saute
- Graduate Program in Medicine, Medical Sciences, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Clinical Neurogenetics research group, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Brazil
- Department of Internal Medicine, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil
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4
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Sharma G, Paganin M, Lauria F, Perenthaler E, Viero G. The SMN-ribosome interplay: a new opportunity for Spinal Muscular Atrophy therapies. Biochem Soc Trans 2024; 52:465-479. [PMID: 38391004 PMCID: PMC10903476 DOI: 10.1042/bst20231116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
The underlying cause of Spinal Muscular Atrophy (SMA) is in the reduction of survival motor neuron (SMN) protein levels due to mutations in the SMN1 gene. The specific effects of SMN protein loss and the resulting pathological alterations are not fully understood. Given the crucial roles of the SMN protein in snRNP biogenesis and its interactions with ribosomes and translation-related proteins and mRNAs, a decrease in SMN levels below a specific threshold in SMA is expected to affect translational control of gene expression. This review covers both direct and indirect SMN interactions across various translation-related cellular compartments and processes, spanning from ribosome biogenesis to local translation and beyond. Additionally, it aims to outline deficiencies and alterations in translation observed in SMA models and patients, while also discussing the implications of the relationship between SMN protein and the translation machinery within the context of current and future therapies.
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5
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Hoolachan JM, McCallion E, Sutton ER, Çetin Ö, Pacheco-Torres P, Dimitriadi M, Sari S, Miller GJ, Okoh M, Walter LM, Claus P, Wood MJA, Tonge DP, Bowerman M. A transcriptomics-based drug repositioning approach to identify drugs with similar activities for the treatment of muscle pathologies in spinal muscular atrophy (SMA) models. Hum Mol Genet 2024; 33:400-425. [PMID: 37947217 PMCID: PMC10877467 DOI: 10.1093/hmg/ddad192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/08/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by the reduction of survival of motor neuron (SMN) protein levels. Although three SMN-augmentation therapies are clinically approved that significantly slow down disease progression, they are unfortunately not cures. Thus, complementary SMN-independent therapies that can target key SMA pathologies and that can support the clinically approved SMN-dependent drugs are the forefront of therapeutic development. We have previously demonstrated that prednisolone, a synthetic glucocorticoid (GC) improved muscle health and survival in severe Smn-/-;SMN2 and intermediate Smn2B/- SMA mice. However, long-term administration of prednisolone can promote myopathy. We thus wanted to identify genes and pathways targeted by prednisolone in skeletal muscle to discover clinically approved drugs that are predicted to emulate prednisolone's activities. Using an RNA-sequencing, bioinformatics, and drug repositioning pipeline on skeletal muscle from symptomatic prednisolone-treated and untreated Smn-/-; SMN2 SMA and Smn+/-; SMN2 healthy mice, we identified molecular targets linked to prednisolone's ameliorative effects and a list of 580 drug candidates with similar predicted activities. Two of these candidates, metformin and oxandrolone, were further investigated in SMA cellular and animal models, which highlighted that these compounds do not have the same ameliorative effects on SMA phenotypes as prednisolone; however, a number of other important drug targets remain. Overall, our work further supports the usefulness of prednisolone's potential as a second-generation therapy for SMA, identifies a list of potential SMA drug treatments and highlights improvements for future transcriptomic-based drug repositioning studies in SMA.
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Affiliation(s)
- Joseph M Hoolachan
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Eve McCallion
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Emma R Sutton
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Özge Çetin
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Paloma Pacheco-Torres
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL910 9AB, United Kingdom
| | - Maria Dimitriadi
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire, AL910 9AB, United Kingdom
| | - Suat Sari
- Department of Pharmaceutical Chemistry, Hacettepe University, Ankara, 06100, Turkey
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Gavin J Miller
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
- Centre for Glycoscience, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Magnus Okoh
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
| | - Lisa M Walter
- SMATHERIA gGmbH – Non-Profit Biomedical Research Institute, Feodor-Lynen-Straße 31, 30625, Hannover, Germany
- Centre of Systems Neuroscience (ZSN), Hannover Medical School, Bünteweg 2, 30559, Hannover, Germany
| | - Peter Claus
- SMATHERIA gGmbH – Non-Profit Biomedical Research Institute, Feodor-Lynen-Straße 31, 30625, Hannover, Germany
- Centre of Systems Neuroscience (ZSN), Hannover Medical School, Bünteweg 2, 30559, Hannover, Germany
| | - Matthew J A Wood
- Department of Paediatrics, University of Oxford, Level 2, Children's Hospital, John Radcliffe, Headington Oxford, OX3 9DU, United Kingdom
| | - Daniel P Tonge
- School of Life Sciences, Huxley Building, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Melissa Bowerman
- School of Medicine, David Weatherall Building, Keele University, Staffordshire, ST5 5BG, United Kingdom
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, United Kingdom
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6
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A link between agrin signalling and Ca v3.2 at the neuromuscular junction in spinal muscular atrophy. Sci Rep 2022; 12:18960. [PMID: 36347955 PMCID: PMC9643518 DOI: 10.1038/s41598-022-23703-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022] Open
Abstract
SMN protein deficiency causes motoneuron disease spinal muscular atrophy (SMA). SMN-based therapies improve patient motor symptoms to variable degrees. An early hallmark of SMA is the perturbation of the neuromuscular junction (NMJ), a synapse between a motoneuron and muscle cell. NMJ formation depends on acetylcholine receptor (AChR) clustering triggered by agrin and its co-receptors lipoprotein receptor-related protein 4 (LRP4) and transmembrane muscle-specific kinase (MuSK) signalling pathway. We have previously shown that flunarizine improves NMJs in SMA model mice, but the mechanisms remain elusive. We show here that flunarizine promotes AChR clustering in cell-autonomous, dose- and agrin-dependent manners in C2C12 myotubes. This is associated with an increase in protein levels of LRP4, integrin-beta-1 and alpha-dystroglycan, three agrin co-receptors. Furthermore, flunarizine enhances MuSK interaction with integrin-beta-1 and phosphotyrosines. Moreover, the drug acts on the expression and splicing of Agrn and Cacna1h genes in a muscle-specific manner. We reveal that the Cacna1h encoded protein Cav3.2 closely associates in vitro with the agrin co-receptor LRP4. In vivo, it is enriched nearby NMJs during neonatal development and the drug increases this immunolabelling in SMA muscles. Thus, flunarizine modulates key players of the NMJ and identifies Cav3.2 as a new protein involved in the NMJ biology.
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7
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Abati E, Manini A, Comi GP, Corti S. Inhibition of myostatin and related signaling pathways for the treatment of muscle atrophy in motor neuron diseases. Cell Mol Life Sci 2022; 79:374. [PMID: 35727341 PMCID: PMC9213329 DOI: 10.1007/s00018-022-04408-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/16/2022] [Accepted: 06/01/2022] [Indexed: 11/26/2022]
Abstract
Myostatin is a negative regulator of skeletal muscle growth secreted by skeletal myocytes. In the past years, myostatin inhibition sparked interest among the scientific community for its potential to enhance muscle growth and to reduce, or even prevent, muscle atrophy. These characteristics make it a promising target for the treatment of muscle atrophy in motor neuron diseases, namely, amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), which are rare neurological diseases, whereby the degeneration of motor neurons leads to progressive muscle loss and paralysis. These diseases carry a huge burden of morbidity and mortality but, despite this unfavorable scenario, several therapeutic advancements have been made in the past years. Indeed, a number of different curative therapies for SMA have been approved, leading to a revolution in the life expectancy and outcomes of SMA patients. Similarly, tofersen, an antisense oligonucleotide, is now undergoing clinical trial phase for use in ALS patients carrying the SOD1 mutation. However, these therapies are not able to completely halt or reverse progression of muscle damage. Recently, a trial evaluating apitegromab, a myostatin inhibitor, in SMA patients was started, following positive results from preclinical studies. In this context, myostatin inhibition could represent a useful strategy to tackle motor symptoms in these patients. The aim of this review is to describe the myostatin pathway and its role in motor neuron diseases, and to summarize and critically discuss preclinical and clinical studies of myostatin inhibitors in SMA and ALS. Then, we will highlight promises and pitfalls related to the use of myostatin inhibitors in the human setting, to aid the scientific community in the development of future clinical trials.
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Affiliation(s)
- Elena Abati
- Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, Neuroscience Section, Neurology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
- Neurology Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Arianna Manini
- Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, Neuroscience Section, Neurology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Giacomo Pietro Comi
- Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, Neuroscience Section, Neurology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
- Neurology Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Stefania Corti
- Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, Neuroscience Section, Neurology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
- Neurology Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
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8
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Perez-Siles G, Ellis M, Ashe A, Grosz B, Vucic S, Kiernan MC, Morris KA, Reddel SW, Kennerson ML. A Compound Heterozygous Mutation in Calpain 1 Identifies a New Genetic Cause for Spinal Muscular Atrophy Type 4 (SMA4). Front Genet 2022; 12:801253. [PMID: 35126465 PMCID: PMC8807693 DOI: 10.3389/fgene.2021.801253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/21/2021] [Indexed: 12/27/2022] Open
Abstract
Spinal Muscular Atrophy (SMA) is a heterogeneous group of neuromuscular diseases characterized by degeneration of anterior horn cells of the spinal cord, leading to muscular atrophy and weakness. Although the major cause of SMA is autosomal recessive exon deletions or loss-of-function mutations of survival motor neuron 1 (SMN1) gene, next generation sequencing technologies are increasing the genetic heterogeneity of SMA. SMA type 4 (SMA4) is an adult onset, less severe form of SMA for which genetic and pathogenic causes remain elusive.Whole exome sequencing in a 30-year-old brother and sister with SMA4 identified a compound heterozygous mutation (p. G492R/p. F610C) in calpain-1 (CAPN1). Mutations in CAPN1 have been previously associated with cerebellar ataxia and hereditary spastic paraplegia. Using skin fibroblasts from a patient bearing the p. G492R/p. F610C mutation, we demonstrate reduced levels of CAPN1 protein and protease activity. Functional characterization of the SMA4 fibroblasts revealed no changes in SMN protein levels and subcellular distribution. Additional cellular pathways associated with SMA remain unaffected in the patient fibroblasts, highlighting the tissue specificity of CAPN1 dysfunction in SMA4 pathophysiology. This study provides genetic and functional evidence of CAPN1 as a novel gene for the SMA4 phenotype and expands the phenotype of CAPN1 mutation disorders.
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Affiliation(s)
- G. Perez-Siles
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
- *Correspondence: G. Perez-Siles , ; M. L. Kennerson,
| | - M. Ellis
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
| | - A. Ashe
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - B. Grosz
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - S. Vucic
- Brain and Nerve Research Center, Concord Clinical School, University of Sydney, Sydney, NSW, Australia
| | - M. C. Kiernan
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - K. A. Morris
- Department of Neurology, Concord Repatriation General Hospital, Sydney, Sydney, NSW, Australia
| | - S. W. Reddel
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - M. L. Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
- Molecular Medicine Laboratory, Concord Repatriation General Hospital, Sydney, NSW, Australia
- *Correspondence: G. Perez-Siles , ; M. L. Kennerson,
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