1
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Holbrook SE, Hicks AN, Martin PB, Hines TJ, Castro HP, Cox GA. Clinically relevant mouse models of severe spinal muscular atrophy with respiratory distress type 1. Hum Mol Genet 2024:ddae116. [PMID: 39128026 DOI: 10.1093/hmg/ddae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/03/2024] [Accepted: 08/04/2024] [Indexed: 08/13/2024] Open
Abstract
Spinal Muscular Atrophy with Respiratory Distress (SMARD1) is a lethal infantile disease, characterized by the loss of motor neurons leading to muscular atrophy, diaphragmatic paralysis, and weakness in the trunk and limbs. Mutations in IGHMBP2, a ubiquitously expressed DNA/RNA helicase, have been shown to cause a wide spectrum of motor neuron disease. Though mutations in IGHMBP2 are mostly associated with SMARD1, milder alleles cause the axonal neuropathy, Charcot-Marie-Tooth disease type 2S (CMT2S), and some null alleles are potentially a risk factor for sudden infant death syndrome (SIDS). Variant heterogeneity studied using an allelic series can be informative in order to create a broad spectrum of models that better exhibit the human variation. We previously identified the nmd2J mouse model of SMARD1, as well as two milder CMT2S mouse models. Here, we used CRISPR-Cas9 genome editing to create three new, more severe Ighmbp2 mouse models of SMARD1, including a null allele, a deletion of C495 (C495del) and a deletion of L362 (L362del). Phenotypic characterization of the IGHMBP2L362del homozygous mutants and IGHMBP2C495del homozygous mutants respectively show a more severe disease presentation than the previous nmd2J model. The IGHMBP2L362del mutants lack a clear denervation in the diaphragm while the IGHMBP2C495del mutants display a neurogenic diaphragmatic phenotype as observed in SMARD1 patients. Characterization of the Ighmbp2-null model indicated neo-natal lethality (median lifespan = 0.5 days). These novel strains expand the spectrum of SMARD1 models to better reflect the clinical continuum observed in the human patients with various IGHMBP2 recessive mutations.
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Affiliation(s)
- Sarah E Holbrook
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
- The University of Maine, 75 Long Rd., Orono, ME 04469 United States
| | - Amy N Hicks
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
| | - Paige B Martin
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
| | - Timothy J Hines
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
| | - Harold P Castro
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
| | - Gregory A Cox
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609 United States
- The University of Maine, 75 Long Rd., Orono, ME 04469 United States
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2
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Rzepnikowska W, Kaminska J, Kochański A. The molecular mechanisms that underlie IGHMBP2-related diseases. Neuropathol Appl Neurobiol 2024; 50:e13005. [PMID: 39119929 DOI: 10.1111/nan.13005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 07/18/2024] [Accepted: 07/20/2024] [Indexed: 08/10/2024]
Abstract
Immunoglobulin Mu-binding protein 2 (IGHMBP2) pathogenic variants result in the fatal, neurodegenerative disease spinal muscular atrophy with respiratory distress type 1 (SMARD1) and the milder, Charcot-Marie-Tooth (CMT) type 2S (CMT2S) neuropathy. More than 20 years after the link between IGHMBP2 and SMARD1 was revealed, and 10 years after the discovery of the association between IGHMBP2 and CMT2S, the pathogenic mechanism of these diseases is still not well defined. The discovery that IGHMBP2 functions as an RNA/DNA helicase was an important step, but it did not reveal the pathogenic mechanism. Helicases are enzymes that use ATP hydrolysis to catalyse the separation of nucleic acid strands. They are involved in numerous cellular processes, including DNA repair and transcription; RNA splicing, transport, editing and degradation; ribosome biogenesis; translation; telomere maintenance; and homologous recombination. IGHMBP2 appears to be a multifunctional factor involved in several cellular processes that regulate gene expression. It is difficult to determine which processes, when dysregulated, lead to pathology. Here, we summarise our current knowledge of the clinical presentation of IGHMBP2-related diseases. We also overview the available models, including yeast, mice and cells, which are used to study the function of IGHMBP2 and the pathogenesis of the related diseases. Further, we discuss the structure of the IGHMBP2 protein and its postulated roles in cellular functioning. Finally, we present potential anomalies that may result in the neurodegeneration observed in IGHMBP2-related disease and highlight the most prominent ones.
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Affiliation(s)
- Weronika Rzepnikowska
- Neuromuscular Unit, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, 02-106, Poland
| | - Joanna Kaminska
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, Warsaw, 02-106, Poland
| | - Andrzej Kochański
- Neuromuscular Unit, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, 02-106, Poland
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3
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Leśniak A, Glińska M, Patalan M, Ostrowska I, Świrska-Sobolewska M, Giżewska-Kacprzak K, Kotkowiak A, Leśniak A, Walczak M, Śmigiel R, Giżewska M. The Clinical Heterogeneity of Spinal Muscular Atrophy with Respiratory Distress Type 1 (SMARD1)-A Report of Three Cases, Including Twins. Genes (Basel) 2024; 15:997. [PMID: 39202358 PMCID: PMC11353554 DOI: 10.3390/genes15080997] [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: 07/05/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 09/03/2024] Open
Abstract
Spinal muscular atrophy with respiratory distress type 1 (SMARD1; OMIM #604320, ORPHA:98920) is a rare autosomal recessive congenital motor neuron disease. It is caused by variants in the IGHMBP2 gene. Clinically, it presents with respiratory failure due to diaphragmatic paralysis, progressive muscle weakness starting in the distal parts of the limbs, dysphagia, and damage to sensory and autonomic nerves. Unlike spinal muscular atrophy (SMA), SMARD1 has a distinct genetic etiology and is not detected in the population newborn screening programs. Most children with SMARD1 do not survive beyond the first year of life due to progressive respiratory failure. Artificial ventilation can prolong survival, but no specific treatment is available. Therapy focuses on mechanical ventilation and improving the patient's quality of life. Research into gene therapy is ongoing. We report three female patients with SMARD1, including twins from a triplet pregnancy. In twin sisters (patient no. 1 and patient no. 2), two heterozygous variants in the IGHMBP2 gene were identified: c.595G>C/p.Ala199Pro and c.1615_1623del/p.Ser539_Tyr541del. In patient no. 3, a variant c.1478C>T/p.Thr493Ile and a variant c.439C>T/p.Arg147* in the IGHMBP2 gene were detected. Our findings underscore the variability of clinical presentations, even among patients sharing the same pathogenic variants in the IGHMBP2 gene, and emphasize the importance of early genetic diagnosis in patients presenting with respiratory failure, with or without associated diaphragmatic muscle paralysis.
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Affiliation(s)
- Alicja Leśniak
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Marta Glińska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Michał Patalan
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Iwona Ostrowska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Monika Świrska-Sobolewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Kaja Giżewska-Kacprzak
- Department of Pediatric and Oncological Surgery, Urology and Hand Surgery, Pomeranian Medical University in Szczecin, Prof. Tadeusz Sokołowski University Clinical Hospital No. 1, 71-252 Szczecin, Poland
| | - Agata Kotkowiak
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Anna Leśniak
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Mieczysław Walczak
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
| | - Robert Śmigiel
- Department of Pediatrics, Endocrinology, Diabetology and Metabolic Diseases, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Maria Giżewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland; (A.L.); (M.G.); (M.G.)
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Heimdörfer D, Vorleuter A, Eschlböck A, Spathopoulou A, Suarez-Cubero M, Farhan H, Reiterer V, Spanjaard M, Schaaf CP, Huber LA, Kremser L, Sarg B, Edenhofer F, Geley S, de Araujo MEG, Huettenhofer A. Truncated variants of MAGEL2 are involved in the etiologies of the Schaaf-Yang and Prader-Willi syndromes. Am J Hum Genet 2024; 111:1383-1404. [PMID: 38908375 PMCID: PMC11267527 DOI: 10.1016/j.ajhg.2024.05.023] [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: 04/16/2024] [Revised: 05/27/2024] [Accepted: 05/29/2024] [Indexed: 06/24/2024] Open
Abstract
The neurodevelopmental disorders Prader-Willi syndrome (PWS) and Schaaf-Yang syndrome (SYS) both arise from genomic alterations within human chromosome 15q11-q13. A deletion of the SNORD116 cluster, encoding small nucleolar RNAs, or frameshift mutations within MAGEL2 result in closely related phenotypes in individuals with PWS or SYS, respectively. By investigation of their subcellular localization, we observed that in contrast to a predominant cytoplasmic localization of wild-type (WT) MAGEL2, a truncated MAGEL2 mutant was evenly distributed between the cytoplasm and the nucleus. To elucidate regulatory pathways that may underlie both diseases, we identified protein interaction partners for WT or mutant MAGEL2, in particular the survival motor neuron protein (SMN), involved in spinal muscular atrophy, and the fragile-X-messenger ribonucleoprotein (FMRP), involved in autism spectrum disorders. The interactome of the non-coding RNA SNORD116 was also investigated by RNA-CoIP. We show that WT and truncated MAGEL2 were both involved in RNA metabolism, while regulation of transcription was mainly observed for WT MAGEL2. Hence, we investigated the influence of MAGEL2 mutations on the expression of genes from the PWS locus, including the SNORD116 cluster. Thereby, we provide evidence for MAGEL2 mutants decreasing the expression of SNORD116, SNORD115, and SNORD109A, as well as protein-coding genes MKRN3 and SNRPN, thus bridging the gap between PWS and SYS.
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Affiliation(s)
- David Heimdörfer
- Institute of Genomics and RNomics, Biocenter Innsbruck, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
| | - Alexander Vorleuter
- Institute of Genomics and RNomics, Biocenter Innsbruck, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Alexander Eschlböck
- Institute for Molecular Biology, Genomics, Stem Cell Biology & Regenerative Medicine Group, University of Innsbruck and CMBI, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Angeliki Spathopoulou
- Institute for Molecular Biology, Genomics, Stem Cell Biology & Regenerative Medicine Group, University of Innsbruck and CMBI, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Marta Suarez-Cubero
- Institute for Molecular Biology, Genomics, Stem Cell Biology & Regenerative Medicine Group, University of Innsbruck and CMBI, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Hesso Farhan
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Veronika Reiterer
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Melanie Spanjaard
- Institute of Human Genetics, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Christian P Schaaf
- Institute of Human Genetics, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Lukas A Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, Innsbruck 6020, Austria
| | - Leopold Kremser
- Institute of Medical Biochemistry, Protein Core Facility, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Bettina Sarg
- Institute of Medical Biochemistry, Protein Core Facility, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Frank Edenhofer
- Institute for Molecular Biology, Genomics, Stem Cell Biology & Regenerative Medicine Group, University of Innsbruck and CMBI, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Stephan Geley
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Mariana E G de Araujo
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, Innsbruck 6020, Austria
| | - Alexander Huettenhofer
- Institute of Genomics and RNomics, Biocenter Innsbruck, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
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5
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Liu L, Zeng S, Li X, Xie Y, Xu K, Yang H, Huang S, Zhao H, Zhang R. Genotype-phenotype correlations of AR-CMT2S in a cohort of axonal Charcot-Marie-Tooth patients from Central South China. J Peripher Nerv Syst 2024; 29:243-251. [PMID: 38772550 DOI: 10.1111/jns.12633] [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: 04/03/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/23/2024]
Abstract
BACKGROUND AND AIMS This study aimed to report nine Charcot-Marie-Tooth disease (CMT) families with six novel IGHMBP2 mutations in our CMT2 cohort and to summarize the genetic and clinical features of all AR-CMT2S patients reported worldwide. METHODS General information, clinical and neurophysiological data of 275 axonal CMT families were collected. Genetic screening was performed by inherited peripheral neuropathy related genes panel or whole exome sequencing. The published papers reporting AR-CMT2S from 2014 to 2023 were searched in Pubmed and Wanfang databases. RESULTS In our CMT2 cohort, we detected 17 AR-CMT2S families carrying IGHMBP2 mutations and eight were published previously. Among these, c.743 T > A (p.Val248Glu), c.884A > G (p.Asp295Gly), c.1256C > A (p.Ser419*), c.2598_2599delGA (p.Lys868Sfs*16), c.1694_1696delATG (p.Asp565del) and c.2509A > T (p.Arg837*) were firstly reported. These patients prominently presented with early-onset typical axonal neuropathy and without respiratory dysfunction. So far, 56 AR-CMT2S patients and 57 different mutations coming from 43 families have been reported in the world. Twenty-nine of 32 missense mutations were clustered in helicase domain and ATPase region. The age at onset ranged from 0.11to 20 years (Mean ± SD: 3.43 ± 3.88 years) and the majority was infantile-onset (<2 years). The initial symptoms included weakness of limbs (19, 29.7%), delayed milestones (12, 18.8%), gait disturbance (11, 17.2%), feet deformity (8, 12.5%), feet drop (8, 12.5%), etc. INTERPRETATION: AR-CMT2S accounted for 6.2% in our CMT2 cohort. We firstly reported six novel IGHMBP2 mutations which expanded the genotypic spectrum of AR-CMT2S. Furthermore, 17 AR-CMT2S families could provide more resources for natural history study, drug research and development.
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Affiliation(s)
- Lei Liu
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Sen Zeng
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Xiaobo Li
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Yongzhi Xie
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Ke Xu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Honglan Yang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Shunxiang Huang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Huadong Zhao
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Ruxu Zhang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, People's Republic of China
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6
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Zhou C, Chen Z, Chen Q, Feng X. Case report: Heterozygous variation in the IGHMBP2 gene leading to spinal muscular atrophy with respiratory distress type 1. Front Neurol 2024; 15:1289625. [PMID: 38872814 PMCID: PMC11169606 DOI: 10.3389/fneur.2024.1289625] [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: 09/06/2023] [Accepted: 05/10/2024] [Indexed: 06/15/2024] Open
Abstract
A rare autosomal recessive genetic disease is spinal muscular atrophy with respiratory distress type 1 (SMARD 1; OMIM #604320), which is characterized by progressive distal limb muscle weakness, muscular atrophy, and early onset of respiratory failure. Herein, we report the case of a 4-month-old female infant with SMARD type 1 who was admitted to our hospital owing to unexplained distal limb muscle weakness and early respiratory failure. This report summarizes the characteristics of SMARD type 1 caused by heterozygous variation in the immunoglobulin mu DNA binding protein 2 (IGHMBP2) gene by analyzing its clinical manifestations, genetic variation characteristics, and related examinations, aiming to deepen clinicians' understanding of the disease, assisting pediatricians in providing medical information to parents and improving the decision-making process involved in establishing life support.
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Affiliation(s)
- Chaoai Zhou
- Department of Pediatrics, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, China
| | - Zefu Chen
- Department of Pediatrics, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, China
| | - Qiqing Chen
- Department of Ultrasound, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, China
| | - Xiaowei Feng
- Department of Pediatrics, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, China
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7
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Jablonka S, Yildirim E. Disease Mechanisms and Therapeutic Approaches in SMARD1-Insights from Animal Models and Cell Models. Biomedicines 2024; 12:845. [PMID: 38672198 PMCID: PMC11048220 DOI: 10.3390/biomedicines12040845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/04/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a fatal childhood motoneuron disease caused by mutations in the IGHMBP2 gene. It is characterized by muscle weakness, initially affecting the distal extremities due to the degeneration of spinal α-motoneurons, and respiratory distress, due to the paralysis of the diaphragm. Infantile forms with a severe course of the disease can be distinguished from juvenile forms with a milder course. Mutations in the IGHMBP2 gene have also been found in patients with peripheral neuropathy Charcot-Marie-Tooth type 2S (CMT2S). IGHMBP2 is an ATP-dependent 5'→3' RNA helicase thought to be involved in translational mechanisms. In recent years, several animal models representing both SMARD1 forms and CMT2S have been generated to initially study disease mechanisms. Later, the models showed very well that both stem cell therapies and the delivery of the human IGHMBP2 cDNA by AAV9 approaches (AAV9-IGHMBP2) can lead to significant improvements in disease symptoms. Therefore, the SMARD1 animal models, in addition to the cellular models, provide an inexhaustible source for obtaining knowledge of disease mechanisms, disease progression at the cellular level, and deeper insights into the development of therapies against SMARD1.
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Affiliation(s)
- Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Würzburg, Versbacher Strasse 5, 97078 Würzburg, Germany;
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8
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Vadla GP, Singh K, Lorson CL, Lorson MA. The contribution and therapeutic implications of IGHMBP2 mutations on IGHMBP2 biochemical activity and ABT1 association. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167091. [PMID: 38403020 PMCID: PMC10999323 DOI: 10.1016/j.bbadis.2024.167091] [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: 11/16/2023] [Revised: 02/01/2024] [Accepted: 02/15/2024] [Indexed: 02/27/2024]
Abstract
Mutations within immunoglobulin mu DNA binding protein (IGHMBP2), an RNA-DNA helicase, result in SMA with respiratory distress type I (SMARD1) and Charcot Marie Tooth type 2S (CMT2S). The underlying biochemical mechanism of IGHMBP2 is unknown as well as the functional significance of IGHMBP2 mutations in disease severity. Here we report the biochemical mechanisms of IGHMBP2 disease-causing mutations D565N and H924Y, and their potential impact on therapeutic strategies. The IGHMBP2-D565N mutation has been identified in SMARD1 patients, while the IGHMBP2-H924Y mutation has been identified in CMT2S patients. For the first time, we demonstrate a correlation between the altered IGHMBP2 biochemical activity associated with the D565N and H924Y mutations and disease severity and pathology in patients and our Ighmbp2 mouse models. We show that IGHMBP2 mutations that alter the association with activator of basal transcription (ABT1) impact the ATPase and helicase activities of IGHMBP2 and the association with the 47S pre-rRNA 5' external transcribed spacer. We demonstrate that the D565N mutation impairs IGHMBP2 ATPase and helicase activities consistent with disease pathology. The H924Y mutation alters IGHMBP2 activity to a lesser extent while maintaining association with ABT1. In the context of the compound heterozygous patient, we demonstrate that the total biochemical activity associated with IGHMBP2-D565N and IGHMBP2-H924Y proteins is improved over IGHMBP2-D565N alone. Importantly, we demonstrate that the efficacy of therapeutic applications may vary based on the underlying IGHMBP2 mutations and the relative biochemical activity of the mutant IGHMBP2 protein.
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Affiliation(s)
- Gangadhar P Vadla
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Kamal Singh
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Christian L Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Monique A Lorson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
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9
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Prusty AB, Hirmer A, Sierra-Delgado JA, Huber H, Guenther UP, Schlosser A, Dybkov O, Yildirim E, Urlaub H, Meyer KC, Jablonka S, Erhard F, Fischer U. RNA helicase IGHMBP2 regulates THO complex to ensure cellular mRNA homeostasis. Cell Rep 2024; 43:113802. [PMID: 38368610 DOI: 10.1016/j.celrep.2024.113802] [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: 08/03/2023] [Revised: 12/21/2023] [Accepted: 01/31/2024] [Indexed: 02/20/2024] Open
Abstract
RNA helicases constitute a large protein family implicated in cellular RNA homeostasis and disease development. Here, we show that the RNA helicase IGHMBP2, linked to the neuromuscular disorder spinal muscular atrophy with respiratory distress type 1 (SMARD1), associates with polysomes and impacts translation of mRNAs containing short, GC-rich, and structured 5' UTRs. The absence of IGHMBP2 causes ribosome stalling at the start codon of target mRNAs, leading to reduced translation efficiency. The main mRNA targets of IGHMBP2-mediated regulation encode for components of the THO complex (THOC), linking IGHMBP2 to mRNA production and nuclear export. Accordingly, failure of IGHMBP2 regulation of THOC causes perturbations of the transcriptome and its encoded proteome, and ablation of THOC subunits phenocopies these changes. Thus, IGHMBP2 is an upstream regulator of THOC. Of note, IGHMBP2-dependent regulation of THOC is also observed in astrocytes derived from patients with SMARD1 disease, suggesting that deregulated mRNA metabolism contributes to SMARD1 etiology and may enable alternative therapeutic avenues.
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Affiliation(s)
| | - Anja Hirmer
- Department of Biochemistry 1, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | | | - Hannes Huber
- Department of Biochemistry 1, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | | | - Andreas Schlosser
- Rudolf-Virchow-Center, Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany
| | - Olexandr Dybkov
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
| | - Ezgi Yildirim
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany; Department of Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany; Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Kathrin C Meyer
- Nationwide Children's Hospital, Center for Gene Therapy, Columbus, OH 43205, USA; Department of Pediatrics, Ohio State University, Columbus, OH 43210, USA
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Florian Erhard
- Institute for Virology and Immunobiology, University of Würzburg, 97078 Würzburg, Germany; Faculty for Informatics and Data Science, University of Regensburg, 93053 Regensburg, Germany.
| | - Utz Fischer
- Department of Biochemistry 1, Biocenter, University of Würzburg, 97074 Würzburg, Germany; Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany.
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Tian Y, Xing J, Shi Y, Yuan E. Exploring the relationship between IGHMBP2 gene mutations and spinal muscular atrophy with respiratory distress type 1 and Charcot-Marie-Tooth disease type 2S: a systematic review. Front Neurosci 2023; 17:1252075. [PMID: 38046662 PMCID: PMC10690808 DOI: 10.3389/fnins.2023.1252075] [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: 07/03/2023] [Accepted: 11/03/2023] [Indexed: 12/05/2023] Open
Abstract
Background IGHMBP2 is a crucial gene for the development and maintenance of the nervous system, especially in the survival of motor neurons. Mutations in this gene have been associated with spinal muscular atrophy with respiratory distress type 1 (SMARD1) and Charcot-Marie-Tooth disease type 2S (CMT2S). Methods We conducted a systematic literature search using the PubMed database to identify studies published up to April 1st, 2023, that investigated the association between IGHMBP2 mutations and SMARD1 or CMT2S. We compared the non-truncating mutations and truncating mutations of the IGHMBP2 gene and selected high-frequency mutations of the IGHMBP2 gene. Results We identified 52 articles that investigated the association between IGHMBP2 mutations and SMARD1/CMT2S. We found 6 hotspot mutations of the IGHMBP2 gene. The truncating mutations in trans were all associated with SMARD1. Conclusion This study provides evidence that the complete LOF mechanism of the IGHMBP2 gene defect may be an important cause of SMARD1.
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Affiliation(s)
- Yuan Tian
- Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jinfang Xing
- Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Ying Shi
- Screening Center, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Enwu Yuan
- Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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11
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Zhang W, Liu B. iSnoDi-MDRF: Identifying snoRNA-Disease Associations Based on Multiple Biological Data by Ranking Framework. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2023; 20:3013-3019. [PMID: 37030816 DOI: 10.1109/tcbb.2023.3258448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Accumulating evidence indicates that the dysregulation of small nucleolar RNAs (snoRNAs) is relevant with diseases. Identifying snoRNA-disease associations by computational methods is desired for biologists, which can save considerable costs and time compared biological experiments. However, it still faces some challenges as followings: (i) Many snoRNAs are detected in recent years, but only a few snoRNAs have been proved to be associated with diseases; (ii) Computational predictors trained with only a few known snoRNA-disease associations fail to accurately identify the snoRNA-disease associations. In this study, we propose a ranking framework, called iSnoDi-MDRF, to identify potential snoRNA-disease associations based on multiple biological data, which has the following highlights: (i) iSnoDi-MDRF integrates ranking framework, which is not only able to identify potential associations between known snoRNAs and diseases, but also can identify diseases associated with new snoRNAs. (ii) Known gene-disease associations are employed to help train a mature model for predicting snoRNA-disease association. Experimental results illustrate that iSnoDi-MDRF is very suitable for identifying potential snoRNA-disease associations. The web server of iSnoDi-MDRF predictor is freely available at http://bliulab.net/iSnoDi-MDRF/.
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Sierra-Delgado JA, Sinha-Ray S, Kaleem A, Ganjibakhsh M, Parvate M, Powers S, Zhang X, Likhite S, Meyer K. In Vitro Modeling as a Tool for Testing Therapeutics for Spinal Muscular Atrophy and IGHMBP2-Related Disorders. BIOLOGY 2023; 12:867. [PMID: 37372153 DOI: 10.3390/biology12060867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
Spinal Muscular Atrophy (SMA) is the leading genetic cause of infant mortality. The most common form of SMA is caused by mutations in the SMN1 gene, located on 5q (SMA). On the other hand, mutations in IGHMBP2 lead to a large disease spectrum with no clear genotype-phenotype correlation, which includes Spinal Muscular Atrophy with Muscular Distress type 1 (SMARD1), an extremely rare form of SMA, and Charcot-Marie-Tooth 2S (CMT2S). We optimized a patient-derived in vitro model system that allows us to expand research on disease pathogenesis and gene function, as well as test the response to the AAV gene therapies we have translated to the clinic. We generated and characterized induced neurons (iN) from SMA and SMARD1/CMT2S patient cell lines. After establishing the lines, we treated the generated neurons with AAV9-mediated gene therapy (AAV9.SMN (Zolgensma) for SMA and AAV9.IGHMBP2 for IGHMBP2 disorders (NCT05152823)) to evaluate the response to treatment. The iNs of both diseases show a characteristic short neurite length and defects in neuronal conversion, which have been reported in the literature before with iPSC modeling. SMA iNs respond to treatment with AAV9.SMN in vitro, showing a partial rescue of the morphology phenotype. For SMARD1/CMT2S iNs, we were able to observe an improvement in the neurite length of neurons after the restoration of IGHMBP2 in all disease cell lines, albeit to a variable extent, with some lines showing better responses to treatment than others. Moreover, this protocol allowed us to classify a variant of uncertain significance on IGHMBP2 on a suspected SMARD1/CMT2S patient. This study will further the understanding of SMA, and SMARD1/CMT2S disease in particular, in the context of variable patient mutations, and might further the development of new treatments, which are urgently needed.
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Affiliation(s)
| | - Shrestha Sinha-Ray
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Abuzar Kaleem
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Meysam Ganjibakhsh
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Mohini Parvate
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Samantha Powers
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Xiaojin Zhang
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Shibi Likhite
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Kathrin Meyer
- The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
- College of Medicine, The Ohio State University, Columbus, OH 43205, USA
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