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Bullock G, Jaffey JA, Cohn LA, Sox E, Hostnik ET, Hutcheson KD, Matero E, Hoffmann KS, Johnson GS, Katz ML. Novel COL5A1 variants and associated disease phenotypes in dogs with classical Ehlers-Danlos syndrome. J Vet Intern Med 2024. [PMID: 39175162 DOI: 10.1111/jvim.17180] [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: 06/23/2024] [Accepted: 08/07/2024] [Indexed: 08/24/2024] Open
Abstract
BACKGROUND Human patients with Ehlers-Danlos syndrome (EDS) are categorized into subtypes based on causative genetic variants and phenotypes. The classical form of EDS, primarily caused by variants in COL5A1 or COL5A2, is a very common subtype in people but is poorly characterized in dogs. OBJECTIVE Describe likely causal COL5A1 variants in dogs with classical EDS, summarize clinical histories, discuss potential disease mechanisms, and draw conclusions about disease prognosis. ANIMALS Seven client-owned dogs that exhibited clinical signs of classical EDS. METHODS Clinical information was recorded from medical records and communication with attending veterinarians and dog owners. To identify potential causal gene sequence variants whole-genome sequence analyses (n = 6) or Sanger sequencing (n = 1) were performed on DNA isolated from the probands. Pathological abnormalities in skin biopsy samples were assessed using histology and electron microscopy in 3 dogs. RESULTS Six distinct heterozygous COL5A1 sequence variants were identified. The most common clinical signs included fragile skin (n = 7), hyperextensible skin (n = 7), joint hypermobility (n = 6), and atrophic scars (n = 5). The median age at last follow-up or death was 12 years (range, 6.5-14 years). Ultrastructural abnormalities in dermal collagen differed among dogs with different COL5A1 variants. CONCLUSION AND CLINICAL IMPORTANCE We describe the genotypic and phenotypic spectrum of the classical subtype of EDS by identifying 6 novel COL5A1 variants in conjunction with detailed clinical histories that included long-term follow-up information in 7 dogs.
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Affiliation(s)
- Garrett Bullock
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Jared A Jaffey
- Department of Specialty Medicine, College of Veterinary Medicine, Midwestern University, Glendale, Arizona, USA
| | - Leah A Cohn
- Department of Veterinary Medicine and Surgery, Veterinary Health Center, University of Missouri, Columbia, Missouri, USA
| | - Erika Sox
- Department of Small Animal Internal Medicine, Ethos Veterinary Emergency and Referral Center, Honolulu, Hawaii, USA
| | - Eric T Hostnik
- Department of Veterinary Clinical Sciences, Veterinary Medical Center, Ohio State University, Columbus, Ohio, USA
| | | | - Erin Matero
- Matero Veterinary Services, Warren, Michigan, USA
| | - Karen S Hoffmann
- Olney-Sandy Spring Veterinary Hospital, Sandy Spring, Maryland, USA
| | - Gary S Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Martin L Katz
- Mason Eye Institute, University of Missouri, Columbia, Missouri, USA
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Ji J, Zhou X, Lu Y, Shen L, Li L, Chen Z, Shi Y, Liao W, Yu L. SCN1A intronic variants impact on Nav1.1 protein expression and sodium channel function, and associated with epilepsy phenotypic severity. Gene 2024; 932:148876. [PMID: 39173978 DOI: 10.1016/j.gene.2024.148876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 07/18/2024] [Accepted: 08/19/2024] [Indexed: 08/24/2024]
Abstract
High-throughput sequencing has identified numerous intronic variants in the SCN1A gene in epilepsy patients. Abnormal mRNA splicing caused by these variants can lead to significant phenotypic differences, but the mechanisms of epileptogenicity and phenotypic differences remain unknown. Two variants, c.4853-1 G>C and c.4853-25 T>A, were identified in intron 25 of SCN1A, which were associated with severe Dravet syndrome (DS) and mild focal epilepsy with febrile seizures plus (FEFS+), respectively. The impact of these variants on protein expression, electrophysiological properties of sodium channels and their correlation with epilepsy severity was investigated through plasmid construction and transfection based on the aberrant spliced mRNA. We found that the expression of truncated mutant proteins was significantly reduced on the cell membrane, and retained in the cytoplasmic endoplasmic reticulum. The mutants caused a decrease in current density, voltage sensitivity, and an increased vulnerability of channel, leading to a partial impairment of sodium channel function. Notably, the expression of DS-related mutant protein on the cell membrane was higher compared to that of FEFS+-related mutant, whereas the sodium channel function impairment caused by DS-related mutant was comparatively milder than that caused by FEFS+-related mutant. Our study suggests that differences in protein expression levels and altered electrophysiological properties of sodium channels play important roles in the manifestation of diverse epileptic phenotypes. The presence of intronic splice site variants may result in severe phenotypes due to the dominant-negative effects, whereas non-canonical splice site variants leading to haploinsufficiency could potentially cause milder phenotypes.
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Affiliation(s)
- Jingjing Ji
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Xijing Zhou
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China; Department of Neurology, The First People's Hospital of Nanning, the Fifth Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Yanting Lu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Lang Shen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Lixia Li
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Zirong Chen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China
| | - Yiwu Shi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, GD, China
| | - Weiping Liao
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, GD, China
| | - Lu Yu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, GX, China.
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3
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Ashokkumar M, Hafer TL, Felton A, Archin NM, Margolis DM, Emerman M, Browne EP. A targeted CRISPR screen identifies ETS1 as a regulator of HIV latency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.03.606477. [PMID: 39211204 PMCID: PMC11360895 DOI: 10.1101/2024.08.03.606477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Human Immunodeficiency virus (HIV) infection is regulated by a wide array of host cell factors that combine to influence viral transcription and latency. To understand the complex relationship between the host cell and HIV latency, we performed a lentiviral CRISPR screen that targeted a set of host cell genes whose expression or activity correlates with HIV expression. We further investigated one of the identified factors - the transcription factor ETS1 and found that it is required for maintenance of HIV latency in a primary CD4 T cell model. Interestingly, ETS1 played divergent roles in actively infected and latently infected CD4 T cells, with knockout of ETS1 leading to reduced HIV expression in actively infected cells, but increased HIV expression in latently infected cells, indicating that ETS1 can play both a positive and negative role in HIV expression. CRISPR/Cas9 knockout of ETS1 in CD4 T cells from ART-suppressed people with HIV (PWH) confirmed that ETS1 maintains transcriptional repression of the clinical HIV reservoir. Transcriptomic profiling of ETS1-depleted cells from PWH identified a set of host cell pathways involved in viral transcription that are controlled by ETS1 in resting CD4 T cells. In particular, we observed that ETS1 knockout increased expression of the long non-coding RNA MALAT1 that has been previously identified as a positive regulator of HIV expression. Furthermore, the impact of ETS1 depletion on HIV expression in latently infected cells was partially dependent on MALAT1. Overall, these data demonstrate that ETS1 is an important regulator of HIV latency and influences expression of several cellular genes, including MALAT1, that could have a direct or indirect impact on HIV expression. Author Summary HIV latency is a major obstacle for the eradication of HIV. However, molecular mechanisms that restrict proviral expression during therapy are not well understood. Identification of host cell factors that silence HIV would create opportunities for targeting these factors to reverse latency and eliminate infected cells. Our study aimed to explore mechanisms of latency in infected cells by employing a lentiviral CRISPR screen and CRISPR/Cas9 knockout in primary CD4 T cells. These experiments revealed that ETS1 is essential for maintaining HIV latency in primary CD4 T cells and we further confirmed ETS1's role in maintaining HIV latency through CRISPR/Cas9 knockout in CD4 T cells from antiretroviral therapy (ART)-suppressed individuals with HIV. Transcriptomic profiling of ETS1-depleted cells from these individuals identified several host cell pathways involved in viral transcription regulated by ETS1, including the long non-coding RNA MALAT1. Overall, our study demonstrates that ETS1 is a critical regulator of HIV latency, affecting the expression of several cellular genes that directly or indirectly influence HIV expression.
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4
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Jiang D, Kejiou N, Qiu Y, Palazzo AF, Pennell M. Genetic and selective constraints on the optimization of gene product diversity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.603951. [PMID: 39091777 PMCID: PMC11291005 DOI: 10.1101/2024.07.17.603951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
RNA and protein expressed from the same gene can have diverse isoforms due to various post-transcriptional and post-translational modifications. For the vast majority of alternative isoforms, It is unknown whether they are adaptive or simply biological noise. As we cannot experimentally probe the function of each isoform, we can ask whether the distribution of isoforms across genes and across species is consistent with expectations from different evolutionary processes. However, there is currently no theoretical framework that can generate such predictions. To address this, we developed a mathematical model where isoform abundances are determined collectively by cis-acting loci, trans-acting factors, gene expression levels, and isoform decay rates to predict isoform abundance distributions across species and genes in the face of mutation, genetic drift, and selection. We found that factors beyond selection, such as effective population size and the number of cis-acting loci, significantly influence evolutionary outcomes. Notably, suboptimal phenotypes are more likely to evolve when the population is small and/or when the number of cis-loci is large. We also explored scenarios where modification processes have both beneficial and detrimental effects, revealing a non-monotonic relationship between effective population size and optimization, demonstrating how opposing selection pressures on cis- and trans-acting loci can constrain the optimization of gene product diversity. As a demonstration of the power of our theory, we compared the expected distribution of A-to-I RNA editing levels in coleoids and found this to be largely consistent with non-adaptive explanations.
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Affiliation(s)
- Daohan Jiang
- Department of Quantitative and Computational Biology, University of Southern California, USA
| | - Nevraj Kejiou
- Department of Biochemistry, University of Toronto, Canada
| | - Yi Qiu
- Department of Biochemistry, University of Toronto, Canada
| | | | - Matt Pennell
- Department of Quantitative and Computational Biology, University of Southern California, USA
- Department of Biological Sciences, University of Southern California, USA
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5
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Aulston BD, Gimse K, Bazick HO, Kramar EA, Pizzo DP, Parra-Rivas LA, Sun J, Branes-Guerrero K, Checka N, Bagheri N, Satyadev N, Carlson-Stevermer J, Saito T, Saido TC, Audhya A, Wood MA, Zylka MJ, Saha K, Roy S. Long term rescue of Alzheimer's deficits in vivo by one-time gene-editing of App C-terminus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598099. [PMID: 38895278 PMCID: PMC11185791 DOI: 10.1101/2024.06.08.598099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Gene-editing technologies promise to create a new class of therapeutics that can achieve permanent correction with a single intervention. Besides eliminating mutant alleles in familial disease, gene-editing can also be used to favorably manipulate upstream pathophysiologic events and alter disease-course in wider patient populations, but few such feasible therapeutic avenues have been reported. Here we use CRISPR-Cas9 to edit the last exon of amyloid precursor protein (App), relevant for Alzheimer's disease (AD). Our strategy effectively eliminates an endocytic (YENPTY) motif at APP C-terminus, while preserving the N-terminus and compensatory APP-homologues. This manipulation favorably alters events along the amyloid-pathway - inhibiting toxic APP-β-cleavage fragments (including Aβ) and upregulating neuroprotective APP-α-cleavage products. AAV-driven editing ameliorates neuropathologic, electrophysiologic, and behavioral deficits in an AD knockin mouse model. Effects persist for many months, and no abnormalities are seen in WT mice even after germline App-editing; underlining overall efficacy and safety. Pathologic alterations in the glial-transcriptome of App-KI mice, as seen by single nuclei RNA-sequencing (sNuc-Seq), are also normalized by App C-terminus editing. Our strategy takes advantage of innate transcriptional rules that render terminal exons insensitive to nonsense-decay, and the upstream manipulation is expected to be effective for all forms of AD. These studies offer a path for a one-time disease-modifying treatment for AD.
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Affiliation(s)
- Brent D. Aulston
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Kirstan Gimse
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53715, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Hannah O. Bazick
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Eniko A. Kramar
- Department of Neurobiology and Behavior, School of Biological Sciences University of California, Irvine 92697-2695, USA
| | - Donald P. Pizzo
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Leonardo A. Parra-Rivas
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Jichao Sun
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
- Present address: Department of Geriatrics and Shenzhen Clinical Research Centre for Geriatrics, Shenzhen People’s Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Kristen Branes-Guerrero
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
- Present address: Eli Lilly Pharmaceuticals, Indianapolis, IN, USA
| | - Nidhi Checka
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Neda Bagheri
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Nihal Satyadev
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
- Present address: Department of Neurology, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Jared Carlson-Stevermer
- Synthego Corporation, 3696 Haven Ave Suite A, Redwood City, CA 94063
- Present address: Serotiny Inc., 329 Oyster Point Boulevard, 3rd Floor, South San Francisco, CA 94080
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi 467-8601, Japan
| | - Takaomi C. Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Marcelo A. Wood
- Department of Neurobiology and Behavior, School of Biological Sciences University of California, Irvine 92697-2695, USA
| | - Mark J. Zylka
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Krishanu Saha
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53715, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Subhojit Roy
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
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6
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Ocieczek P, Oluonye N, Méjécase C, Schiff E, Tailor V, Moosajee M. Identification of a Novel Frameshift Variant in MYF5 Leading to External Ophthalmoplegia with Rib and Vertebral Anomalies. Genes (Basel) 2024; 15:699. [PMID: 38927634 PMCID: PMC11202668 DOI: 10.3390/genes15060699] [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: 04/28/2024] [Revised: 05/16/2024] [Accepted: 05/25/2024] [Indexed: 06/28/2024] Open
Abstract
Myogenic transcription factors with a basic helix-loop-helix (bHLH) such as MYOD, myogenin, MRF4, and MYF5 contribute to muscle differentiation and regulation. The MYF5 gene located on chromosome 12 encodes for myogenic factor 5 (MYF5), which has a role in skeletal and extraocular muscle development and rib formation. Variants in MYF5 were found to cause external ophthalmoplegia with rib and vertebral anomalies (EORVA), a rare recessive condition. To date, three homozygous variants in MYF5 have been reported to cause EORVA in six members of four unrelated families. Here, we present a novel homozygous MYF5 frameshift variant, c.596dupA p. (Asn199Lysfs*49), causing premature protein termination and presenting with external ophthalmoplegia, ptosis, and scoliosis in three siblings from a consanguineous family of Pakistani origin. With four MYF5 variants now discovered, genetic testing and paediatric assessment for extra-ocular features should be considered in all cases of congenital ophthalmoplegia.
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Affiliation(s)
- Paulina Ocieczek
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; (P.O.)
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Ngozi Oluonye
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; (P.O.)
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 9JH, UK
| | - Cécile Méjécase
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Francis Crick Institute, London NW1 1AT, UK
| | - Elena Schiff
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; (P.O.)
| | - Vijay Tailor
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; (P.O.)
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Mariya Moosajee
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; (P.O.)
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 9JH, UK
- Francis Crick Institute, London NW1 1AT, UK
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7
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Sun L, Han Y, Li B, Yang Y, Fang Y, Ren X, An L, Hou X, Fan H, Wu Y. A Novel Frameshift Variant of the ELF4 Gene in a Patient with Autoinflammatory Disease: Clinical Features, Transcriptomic Profiling and Functional Studies. J Clin Immunol 2024; 44:127. [PMID: 38773005 DOI: 10.1007/s10875-024-01732-7] [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: 12/07/2023] [Accepted: 05/07/2024] [Indexed: 05/23/2024]
Abstract
We described the diagnosis and treatment of a patient with autoinflammatory disease, named "Deficiency in ELF4, X-linked (DEX)". A novel ELF4 variant was discovered and its pathogenic mechanism was elucidated. The data about clinical, laboratory and endoscopic features, treatment, and follow-up of a patient with DEX were analyzed. Whole exome sequencing and Sanger sequencing were performed to identify potential pathogenic variants. The mRNA and protein levels of ELF4 were analyzed by qPCR and Western blotting, respectively. The association of ELF4 frameshift variant with nonsense-mediated mRNA decay (NMD) in the pathogenesis DEX was examined. Moreover, RNA-seq was performed to identify the key molecular events triggered by ELF4 variant. The relationship between ELF4 and IFN-β activity was validated using a dual-luciferase reporter assay and a ChIP-qPCR assay. An 11-year-old boy presented with a Behçet's-like phenotype. The laboratory abnormality was the most obvious in elevated inflammatory indicators. Endoscopy revealed multiple ileocecal ulcers. Intestinal histopathology showed inflammatory cell infiltrations. The patient was treated with long-term immunosuppressant and TNF-α blocker (adalimumab), which reaped an excellent response over 16 months of follow-up. Genetic analysis identified a maternal hemizygote frameshift variant (c.1022del, p.Q341Rfs*30) in ELF4 gene in the proband. The novel variant decreased the mRNA level of ELF4 via the NMD pathway. Mechanistically, insufficient expression of ELF4 disturbed the immune system, leading to immunological disorders and pathogen susceptibility, and disrupted ELF4-activating IFN-β responses. This analysis detailed the clinical characteristics of a Chinese patient with DEX who harbored a novel ELF4 frameshift variant. For the first time, we used patient-derived cells and carried out transcriptomic analysis to delve into the mechanism of ELF4 variant in DEX.
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Affiliation(s)
- Lina Sun
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, No.28 Xianning West Road, Xi'an, Shaanxi, 710049, China
- Department of Gastroenterology, Xi'an Children's Hospital, Xi'an, China
| | - Ya'nan Han
- Department of Gastroenterology, Xi'an Children's Hospital, Xi'an, China
| | - Benchang Li
- Shaanxi Institute of Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Ying Yang
- Shaanxi Institute of Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Ying Fang
- Department of Gastroenterology, Xi'an Children's Hospital, Xi'an, China
| | - Xiaoxia Ren
- Department of Gastroenterology, Xi'an Children's Hospital, Xi'an, China
| | - Lu An
- Department of Pathology, Xi'an Children's Hospital, Xi'an, China
| | - Xin Hou
- Department of Imaging, Xi'an Children's Hospital, Xi'an, China
| | - Huafeng Fan
- Department of Education Science, Xi'an Children's Hospital, Xi'an, China
| | - Yi Wu
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, No.28 Xianning West Road, Xi'an, Shaanxi, 710049, China.
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8
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Thu KL, Yoon JY. ATM-the gene at the moment in non-small cell lung cancer. Transl Lung Cancer Res 2024; 13:699-705. [PMID: 38601449 PMCID: PMC11002499 DOI: 10.21037/tlcr-23-853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 02/26/2024] [Indexed: 04/12/2024]
Affiliation(s)
- Kelsie L. Thu
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Keenan Research Centre for Biomedical Sciences, St. Michael’s Hospital of Unity Health Toronto, Toronto, Canada
| | - Ju-Yoon Yoon
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Department of Laboratory Medicine, Division of Pathology, Unity Health Toronto, Toronto, Canada
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9
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Mudau MM, Dillon B, Smal C, Feben C, Honey E, Carstens N, Krause A. Mutation analysis and clinical profile of South African patients with Neurofibromatosis type 1 (NF1) phenotype. Front Genet 2024; 15:1331278. [PMID: 38596211 PMCID: PMC11002079 DOI: 10.3389/fgene.2024.1331278] [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: 10/31/2023] [Accepted: 03/11/2024] [Indexed: 04/11/2024] Open
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic condition with complete age-dependent penetrance, variable expressivity and a global prevalence of ∼1/3,000. It is characteriszed by numerous café-au-lait macules, skin freckling in the inguinal or axillary regions, Lisch nodules of the iris, optic gliomas, neurofibromas, and tumour predisposition. The diagnostic testing strategy for NF1 includes testing for DNA single nucleotide variants (SNVs), copy number variants (CNVs) as well as RNA analysis for deep intronic and splice variants, which can cumulatively identify the causative variant in 95% of patients. In the present study, NF1 patients were screened using a next-generation sequencing (NGS) assay targeting NF1 exons and intron/exon boundaries for SNV and NF1 multiple ligation-dependent probe amplification (MLPA) analysis for CNV detection. Twenty-six unrelated Southern African patients clinically suspected of having NF1, based on the clinical diagnostic criteria developed by the National Institute of Health (NIH), were included in the current study. A detection rate of 58% (15/26) was obtained, with SNVs identified in 80% (12/15) using a targeted gene panel and NF1 gene deletion in 20% (3/15) identified using MLPA. Ten patients (38%) had no variants identified, although they met NF1 diagnostic criteria. One VUS was identified in this study in a patient that met NF1 diagnostic criteria, however there was no sufficient information to classify variant as pathogenic. The clinical features of Southern African patients with NF1 are similar to that of the known NF1 phenotype, with the exception of a lower frequency of plexiform neurofibromas and a higher frequency of developmental/intellectual disability compared to other cohorts. This is the first clinical and molecular characterisation of a Southern African ancestry NF1 cohort using both next-generation sequencing and MLPA analysis. A significant number of patients remained without a diagnosis following DNA-level testing. The current study offers a potential molecular testing strategy for our low resource environment that could benefit a significant proportion of patients who previously only received a clinical diagnosis without molecular confirmation.
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Affiliation(s)
- Maria Mabyalwa Mudau
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Bronwyn Dillon
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Clarice Smal
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Candice Feben
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Engela Honey
- Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Nadia Carstens
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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10
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Pacheco M, D’Orazio KN, Lessen LN, Veltri AJ, Neiman Z, Loll-Krippleber R, Brown GW, Green R. Genetic screens in Saccharomyces cerevisiae identify a role for 40S ribosome recycling factors Tma20 and Tma22 in nonsense-mediated decay. G3 (BETHESDA, MD.) 2024; 14:jkad295. [PMID: 38198768 PMCID: PMC10917514 DOI: 10.1093/g3journal/jkad295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 08/29/2023] [Accepted: 12/06/2023] [Indexed: 01/12/2024]
Abstract
The decay of messenger RNA with a premature termination codon by nonsense-mediated decay (NMD) is an important regulatory pathway for eukaryotes and an essential pathway in mammals. NMD is typically triggered by the ribosome terminating at a stop codon that is aberrantly distant from the poly-A tail. Here, we use a fluorescence screen to identify factors involved in NMD in Saccharomyces cerevisiae. In addition to the known NMD factors, including the entire UPF family (UPF1, UPF2, and UPF3), as well as NMD4 and EBS1, we identify factors known to function in posttermination recycling and characterize their contribution to NMD. These observations in S. cerevisiae expand on data in mammals indicating that the 60S recycling factor ABCE1 is important for NMD by showing that perturbations in factors implicated in 40S recycling also correlate with a loss of NMD.
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Affiliation(s)
- Miguel Pacheco
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Karole N D’Orazio
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Laura N Lessen
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anthony J Veltri
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Zachary Neiman
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Raphael Loll-Krippleber
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Rachel Green
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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11
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Mattijssen S, Kerkhofs K, Stephen J, Yang A, Han CG, Tadafumi Y, Iben JR, Mishra S, Sakhawala RM, Ranjan A, Gowda M, Gahl WA, Gu S, Malicdan MC, Maraia RJ. A POLR3B-variant reveals a Pol III transcriptome response dependent on La protein/SSB. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.577363. [PMID: 38410490 PMCID: PMC10896340 DOI: 10.1101/2024.02.05.577363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
RNA polymerase III (Pol III, POLR3) synthesizes tRNAs and other small non-coding RNAs. Human POLR3 pathogenic variants cause a range of developmental disorders, recapitulated in part by mouse models, yet some aspects of POLR3 deficiency have not been explored. We characterized a human POLR3B:c.1625A>G;p.(Asn542Ser) disease variant that was found to cause mis-splicing of POLR3B. Genome-edited POLR3B1625A>G HEK293 cells acquired the mis-splicing with decreases in multiple POLR3 subunits and TFIIIB, although display auto-upregulation of the Pol III termination-reinitiation subunit POLR3E. La protein was increased relative to its abundant pre-tRNA ligands which bind via their U(n)U-3'-termini. Assays for cellular transcription revealed greater deficiencies for tRNA genes bearing terminators comprised of 4Ts than of ≥5Ts. La-knockdown decreased Pol III ncRNA expression unlinked to RNA stability. Consistent with these effects, small-RNAseq showed that POLR3B1625A>G and patient fibroblasts express more tRNA fragments (tRFs) derived from pre-tRNA 3'-trailers (tRF-1) than from mature-tRFs, and higher levels of multiple miRNAs, relative to control cells. The data indicate that decreased levels of Pol III transcripts can lead to functional excess of La protein which reshapes small ncRNA profiles revealing new depth in the Pol III system. Finally, patient cell RNA analysis uncovered a strategy for tRF-1/tRF-3 as POLR3-deficiency biomarkers.
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Affiliation(s)
- Sandy Mattijssen
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Kyra Kerkhofs
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Joshi Stephen
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Acong Yang
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD, 21702 USA
| | - Chen G. Han
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Yokoyama Tadafumi
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - James R. Iben
- Molecular Genetics Core, NICHD, NIH, Bethesda, MD 20892, USA
| | - Saurabh Mishra
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Rima M. Sakhawala
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Amitabh Ranjan
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Mamatha Gowda
- Department of Obstetrics & Gynaecology, Jawaharlal Institute of Post-Graduate Medical Education and Research, Puducherry, India
| | - William A. Gahl
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
- NIH Undiagnosed Diseases Program, NIH, Bethesda, MD 20892, USA
| | - Shuo Gu
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD, 21702 USA
| | - May C. Malicdan
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
- NIH Undiagnosed Diseases Program, NIH, Bethesda, MD 20892, USA
| | - Richard J. Maraia
- Section on Molecular and Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USA
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12
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Nishadham V, Santhoshkumar R, Nashi S, Vengalil S, Bardhan M, Polavarapu K, Sanka SB, Anjanappa RM, Kulanthaivelu K, Saini J, Chickabasaviah YT, Nalini A. A Novel Mutation in Frabin (FGD4) Causing a Mild Phenotype of CMT4H in an Indian Patient. J Neuromuscul Dis 2024; 11:221-232. [PMID: 38108359 PMCID: PMC10789318 DOI: 10.3233/jnd-230042] [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] [Accepted: 10/31/2023] [Indexed: 12/19/2023]
Abstract
Charcot-Marie-Tooth disease 4H(CMT4H) is an autosomal recessive demyelinating form of CMT caused by FGD4/FRABIN mutations. CMT4H is characterized by early onset and slowly progressing motor and sensory deficits in the distal extremities, along with foot deformities. We describe a patient with CMT4H who presented with rapidly progressing flaccid quadriparesis during the postpartum period, which improved significantly with steroid therapy. Magnetic resonance imaging and ultrasonography demonstrated considerable nerve thickening with increased cross-sectional area in the peripheral nerves. A nerve biopsy revealed significant demyelination and myelin outfolding. This is the first report of an Indian patient with a novel homozygous nonsense c.1672C>T (p.Arg558Ter) mutation in the FGD4 gene, expanding the mutational and phenotypic spectrum of this disease.
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Affiliation(s)
- Vikas Nishadham
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Rashmi Santhoshkumar
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Sai Bhargava Sanka
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Ram Murthy Anjanappa
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Karthik Kulanthaivelu
- Department of Neurointerventional and Imaging, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Jitender Saini
- Department of Neurointerventional and Imaging, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Yasha T. Chickabasaviah
- Department of Neuropathology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
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13
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Carrard J, Lejeune F. Nonsense-mediated mRNA decay, a simplified view of a complex mechanism. BMB Rep 2023; 56:625-632. [PMID: 38052423 PMCID: PMC10761751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/31/2023] [Accepted: 11/17/2023] [Indexed: 12/07/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is both a quality control mechanism and a gene regulation pathway. It has been studied for more than 30 years, with an accumulation of many mechanistic details that have often led to debate and hence to different models of NMD activation, particularly in higher eukaryotes. Two models seem to be opposed, since the first requires intervention of the exon junction complex (EJC) to recruit NMD factors downstream of the premature termination codon (PTC), whereas the second involves an EJC-independent mechanism in which NMD factors concentrate in the 3'UTR to initiate NMD in the presence of a PTC. In this review we describe both models, giving recent molecular details and providing experimental arguments supporting one or the other model. In the end it is certainly possible to imagine that these two mechanisms co-exist, rather than viewing them as mutually exclusive. [BMB Reports 2023; 56(12): 625-632].
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Affiliation(s)
- Julie Carrard
- Univ. Lille, CNRS, Inserm, UMR9020-U1277 - CANTHER - Cancer Heterogeneity Plasticity and Resistance to Therapies, Lille F-59000, France
| | - Fabrice Lejeune
- Univ. Lille, CNRS, Inserm, UMR9020-U1277 - CANTHER - Cancer Heterogeneity Plasticity and Resistance to Therapies, Lille F-59000, France
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14
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Akbari B, Ahmadi E, Zabihi MR, Zamir MR, Shaker MS, Noorbakhsh F. SARS-CoV-2 helicase might interfere with cellular nonsense-mediated RNA decay: insights from a bioinformatics study. BMC Genom Data 2023; 24:68. [PMID: 37980504 PMCID: PMC10657555 DOI: 10.1186/s12863-023-01173-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 11/10/2023] [Indexed: 11/20/2023] Open
Abstract
BACKGROUND Viruses employ diverse strategies to interfere with host defense mechanisms, including the production of proteins that mimic or resemble host proteins. This study aimed to analyze the similarities between SARS-CoV-2 and human proteins, investigate their impact on virus-host interactions, and elucidate underlying mechanisms. RESULTS Comparing the proteins of SARS-CoV-2 with human and mammalian proteins revealed sequence and structural similarities between viral helicase with human UPF1. The latter is a protein that is involved in nonsense-mediated RNA decay (NMD), an mRNA surveillance pathway which also acts as a cellular defense mechanism against viruses. Protein sequence similarities were also observed between viral nsp3 and human Poly ADP-ribose polymerase (PARP) family of proteins. Gene set enrichment analysis on transcriptomic data derived from SARS-CoV-2 positive samples illustrated the enrichment of genes belonging to the NMD pathway compared with control samples. Moreover, comparing transcriptomic data from SARS-CoV-2-infected samples with transcriptomic data derived from UPF1 knockdown cells demonstrated a significant overlap between datasets. CONCLUSIONS These findings suggest that helicase/UPF1 sequence and structural similarity might have the ability to interfere with the NMD pathway with pathogenic and immunological implications.
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Affiliation(s)
- Behnia Akbari
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ehsan Ahmadi
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zabihi
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Roshan Zamir
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Sadeghi Shaker
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Farshid Noorbakhsh
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.
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15
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Oftedal BE, Berger AH, Bruserud Ø, Goldfarb Y, Sulen A, Breivik L, Hellesen A, Ben-Dor S, Haffner-Krausz R, Knappskog PM, Johansson S, Wolff AS, Bratland E, Abramson J, Husebye ES. A partial form of AIRE deficiency underlies a mild form of autoimmune polyendocrine syndrome type 1. J Clin Invest 2023; 133:e169704. [PMID: 37909333 PMCID: PMC10617782 DOI: 10.1172/jci169704] [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: 02/13/2023] [Accepted: 08/29/2023] [Indexed: 11/03/2023] Open
Abstract
Autoimmune polyendocrine syndrome type 1 (APS-1) is caused by mutations in the autoimmune regulator (AIRE) gene. Most patients present with severe chronic mucocutaneous candidiasis and organ-specific autoimmunity from early childhood, but the clinical picture is highly variable. AIRE is crucial for negative selection of T cells, and scrutiny of different patient mutations has previously highlighted many of its molecular mechanisms. In patients with a milder adult-onset phenotype sharing a mutation in the canonical donor splice site of intron 7 (c.879+1G>A), both the predicted altered splicing pattern with loss of exon 7 (AireEx7-/-) and normal full-length AIRE mRNA were found, indicating leaky rather than abolished mRNA splicing. Analysis of a corresponding mouse model demonstrated that the AireEx7-/- mutant had dramatically impaired transcriptional capacity of tissue-specific antigens in medullary thymic epithelial cells but still retained some ability to induce gene expression compared with the complete loss-of-function AireC313X-/- mutant. Our data illustrate an association between AIRE activity and the severity of autoimmune disease, with implications for more common autoimmune diseases associated with AIRE variants, such as primary adrenal insufficiency, pernicious anemia, type 1 diabetes, and rheumatoid arthritis.
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Affiliation(s)
- Bergithe Eikeland Oftedal
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medicine and
| | - Amund Holte Berger
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Øyvind Bruserud
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medicine and
| | - Yael Goldfarb
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Andre Sulen
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
| | - Lars Breivik
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medicine and
| | - Alexander Hellesen
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
| | - Shifra Ben-Dor
- Bioinformatics Unit, Department of Life Sciences Core Facilities and
| | | | - Per M. Knappskog
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Stefan Johansson
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Anette S.B. Wolff
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medicine and
| | - Eirik Bratland
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Jakub Abramson
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eystein Sverre Husebye
- Department of Clinical Science and KG Jebsen Center for Autoimmune Diseases, University of Bergen, Norway
- Department of Medicine and
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16
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Mohammadi MF, Fateh ST, Aghajani H, Bahramy A, Zaheryani SMS, Behroozi J, Kahani SM, Mohammadi P, Garshasbi M. Expression assay of the COLQ in a family with congenital myasthenic syndrome and symptomatic carriers. Clin Case Rep 2023; 11:e8062. [PMID: 37881193 PMCID: PMC10593973 DOI: 10.1002/ccr3.8062] [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: 06/30/2023] [Revised: 08/20/2023] [Accepted: 10/04/2023] [Indexed: 10/27/2023] Open
Abstract
Congenital myasthenic syndromes-5 (CMS5) is a rare autosomal recessive heterogeneous disorder, caused by pathogenic variants in the COLQ that lead to skeletal muscle weakness and abnormal fatigability. The onset is usually from birth to childhood. Disease-causing variants in the collagen-like tail subunit are the most explained etiology in synaptic CMS, causing defected acetylcholinesterase. In this study whole-exome sequencing (WES) was performed in an affected boy with muscle weakness, ophthalmoplegia, and bilateral ptosis and gene expression assay by qRT-PCR was performed in entire family. A homozygous nonsense variant in the COLQ [NM_005677.4:c.679C>T], (p.Arg227Ter) was identified in the proband. Segregation analysis by Sanger sequencing confirmed the homozygous state in the proband and heterozygous state in his parents and four of the siblings. The mRNA expression level in the proband was 0.02 of a healthy person, and in the carriers were 0.42 of a healthy person. This study presents an Iranian family with two affected children and eight symptomatic carriers with attenuated mRNA expression. This study provides evidence that carriers of the COLQ disease-causing variants could become symptomatic with some yet unknown pathogenesis mechanism and underscore the importance of further investigations to elucidate this mechanism.
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Affiliation(s)
- Mohammad Farid Mohammadi
- Department of Cell and Molecular Sciences, Faculty of Biological SciencesKharazmi UniversityTehranIran
| | | | - Hadi Aghajani
- Faculty of Medicine, Tehran Medical Sciences BranchIslamic Azad UniversityTehranIran
| | - Afshin Bahramy
- Department of Medical Genetics, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | | | - Javad Behroozi
- Department of Medical Genetics, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
- Research Center for Cancer Screening and EpidemiologyAJA University of Medical SciencesTehranIran
| | - Seyyed Mohammad Kahani
- Department of Medical Genetics, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Pouria Mohammadi
- Department of Medical Genetics, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical SciencesTarbiat Modares UniversityTehranIran
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17
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Valášek LS, Kučerová M, Zeman J, Beznosková P. Cysteine tRNA acts as a stop codon readthrough-inducing tRNA in the human HEK293T cell line. RNA (NEW YORK, N.Y.) 2023; 29:1379-1387. [PMID: 37221013 PMCID: PMC10573299 DOI: 10.1261/rna.079688.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/12/2023] [Indexed: 05/25/2023]
Abstract
Under certain circumstances, any of the three termination codons can be read through by a near-cognate tRNA; i.e., a tRNA whose two out of three anticodon nucleotides base pair with those of the stop codon. Unless programed to synthetize C-terminally extended protein variants with expanded physiological roles, readthrough represents an undesirable translational error. On the other side of a coin, a significant number of human genetic diseases is associated with the introduction of nonsense mutations (premature termination codons [PTCs]) into coding sequences, where stopping is not desirable. Here, the tRNA's ability to induce readthrough opens up the intriguing possibility of mitigating the deleterious effects of PTCs on human health. In yeast, the UGA and UAR stop codons were described to be read through by four readthrough-inducing rti-tRNAs-tRNATrp and tRNACys, and tRNATyr and tRNAGln, respectively. The readthrough-inducing potential of tRNATrp and tRNATyr was also observed in human cell lines. Here, we investigated the readthrough-inducing potential of human tRNACys in the HEK293T cell line. The tRNACys family consists of two isoacceptors, one with ACA and the other with GCA anticodons. We selected nine representative tRNACys isodecoders (differing in primary sequence and expression level) and tested them using dual luciferase reporter assays. We found that at least two tRNACys can significantly elevate UGA readthrough when overexpressed. This indicates a mechanistically conserved nature of rti-tRNAs between yeast and human, supporting the idea that they could be used in the PTC-associated RNA therapies.
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MESH Headings
- Humans
- Codon, Terminator/genetics
- Cysteine/genetics
- Cysteine/metabolism
- HEK293 Cells
- Saccharomyces cerevisiae/genetics
- RNA, Transfer, Cys/metabolism
- RNA, Transfer, Trp/metabolism
- RNA, Transfer, Tyr
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Anticodon
- Codon, Nonsense/genetics
- Protein Biosynthesis
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Affiliation(s)
- Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Michaela Kučerová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
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18
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Brownmiller T, Caplen NJ. The HNRNPF/H RNA binding proteins and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1788. [PMID: 37042074 PMCID: PMC10523889 DOI: 10.1002/wrna.1788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 04/13/2023]
Abstract
The members of the HNRNPF/H family of heterogeneous nuclear RNA proteins-HNRNPF, HNRNPH1, HNRNPH2, HNRNPH3, and GRSF1, are critical regulators of RNA maturation. Documented functions of these proteins include regulating splicing, particularly alternative splicing, 5' capping and 3' polyadenylation of RNAs, and RNA export. The assignment of these proteins to the HNRNPF/H protein family members relates to differences in the amino acid composition of their RNA recognition motifs, which differ from those of other RNA binding proteins (RBPs). HNRNPF/H proteins typically bind RNA sequences enriched with guanine (G) residues, including sequences that, in the presence of a cation, have the potential to form higher-order G-quadruplex structures. The need to further investigate members of the HNRNPF/H family of RBPs has intensified with the recent descriptions of their involvement in several disease states, including the pediatric tumor Ewing sarcoma and the hematological malignancy mantle cell lymphoma; newly described groups of developmental syndromes; and neuronal-related disorders, including addictive behavior. Here, to foster the study of the HNRNPF/H family of RBPs, we discuss features of the genes encoding these proteins, their structures and functions, and emerging contributions to disease. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Tayvia Brownmiller
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, DHHS, Bethesda, Maryland, USA
| | - Natasha J Caplen
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, DHHS, Bethesda, Maryland, USA
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19
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Sun B, Chen L. Mapping genetic variants for nonsense-mediated mRNA decay regulation across human tissues. Genome Biol 2023; 24:164. [PMID: 37434206 PMCID: PMC10337212 DOI: 10.1186/s13059-023-03004-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/30/2023] [Indexed: 07/13/2023] Open
Abstract
BACKGROUND Nonsense-mediated mRNA decay (NMD) was originally conceived as an mRNA surveillance mechanism to prevent the production of potentially deleterious truncated proteins. Research also shows NMD is an important post-transcriptional gene regulation mechanism selectively targeting many non-aberrant mRNAs. However, how natural genetic variants affect NMD and modulate gene expression remains elusive. RESULTS Here we elucidate NMD regulation of individual genes across human tissues through genetical genomics. Genetic variants corresponding to NMD regulation are identified based on GTEx data through unique and robust transcript expression modeling. We identify genetic variants that influence the percentage of NMD-targeted transcripts (pNMD-QTLs), as well as genetic variants regulating the decay efficiency of NMD-targeted transcripts (dNMD-QTLs). Many such variants are missed in traditional expression quantitative trait locus (eQTL) mapping. NMD-QTLs show strong tissue specificity especially in the brain. They are more likely to overlap with disease single-nucleotide polymorphisms (SNPs). Compared to eQTLs, NMD-QTLs are more likely to be located within gene bodies and exons, especially the penultimate exons from the 3' end. Furthermore, NMD-QTLs are more likely to be found in the binding sites of miRNAs and RNA binding proteins. CONCLUSIONS We reveal the genome-wide landscape of genetic variants associated with NMD regulation across human tissues. Our analysis results indicate important roles of NMD in the brain. The preferential genomic positions of NMD-QTLs suggest key attributes for NMD regulation. Furthermore, the overlap with disease-associated SNPs and post-transcriptional regulatory elements implicates regulatory roles of NMD-QTLs in disease manifestation and their interactions with other post-transcriptional regulators.
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Affiliation(s)
- Bo Sun
- Department of Quantitative and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA, 90089, USA
| | - Liang Chen
- Department of Quantitative and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA, 90089, USA.
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20
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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21
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Muñoz O, Lore M, Jagannathan S. The long and short of EJC-independent nonsense-mediated RNA decay. Biochem Soc Trans 2023; 51:1121-1129. [PMID: 37145092 DOI: 10.1042/bst20221131] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Nonsense-mediated RNA decay (NMD) plays a dual role as an RNA surveillance mechanism against aberrant transcripts containing premature termination codons and as a gene regulatory mechanism for normal physiological transcripts. This dual function is possible because NMD recognizes its substrates based on the functional definition of a premature translation termination event. An efficient mode of NMD target recognition involves the presence of exon-junction complexes (EJCs) downstream of the terminating ribosome. A less efficient, but highly conserved, mode of NMD is triggered by long 3' untranslated regions (UTRs) that lack EJCs (termed EJC-independent NMD). While EJC-independent NMD plays an important regulatory role across organisms, our understanding of its mechanism, especially in mammalian cells, is incomplete. This review focuses on EJC-independent NMD and discusses the current state of knowledge and factors that contribute to the variability in the efficiency of this mechanism.
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Affiliation(s)
- Oscar Muñoz
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
| | - Mlana Lore
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A
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22
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de la Peña JB, Chase R, Kunder N, Smith PR, Lou TF, Stanowick A, Suresh P, Shukla T, Butcher SE, Price TJ, Campbell ZT. Inhibition of Nonsense-Mediated Decay Induces Nociceptive Sensitization through Activation of the Integrated Stress Response. J Neurosci 2023; 43:2921-2933. [PMID: 36894318 PMCID: PMC10124962 DOI: 10.1523/jneurosci.1604-22.2023] [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: 08/22/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
RNA stability is meticulously controlled. Here, we sought to determine whether an essential post-transcriptional regulatory mechanism plays a role in pain. Nonsense-mediated decay (NMD) safeguards against translation of mRNAs that harbor premature termination codons and controls the stability of ∼10% of typical protein-coding mRNAs. It hinges on the activity of the conserved kinase SMG1. Both SMG1 and its target, UPF1, are expressed in murine DRG sensory neurons. SMG1 protein is present in both the DRG and sciatic nerve. Using high-throughput sequencing, we examined changes in mRNA abundance following inhibition of SMG1. We confirmed multiple NMD stability targets in sensory neurons, including ATF4. ATF4 is preferentially translated during the integrated stress response (ISR). This led us to ask whether suspension of NMD induces the ISR. Inhibition of NMD increased eIF2-α phosphorylation and reduced the abundance of the eIF2-α phosphatase constitutive repressor of eIF2-α phosphorylation. Finally, we examined the effects of SMG1 inhibition on pain-associated behaviors. Peripheral inhibition of SMG1 results in mechanical hypersensitivity in males and females that persists for several days and priming to a subthreshold dose of PGE2. Priming was fully rescued by a small-molecule inhibitor of the ISR. Collectively, our results indicate that suspension of NMD promotes pain through stimulation of the ISR.SIGNIFICANCE STATEMENT Nociceptors undergo long-lived changes in their plasticity which may contribute to chronic pain. Translational regulation has emerged as a dominant mechanism in pain. Here, we investigate the role of a major pathway of RNA surveillance called nonsense-mediated decay (NMD). Modulation of NMD is potentially beneficial for a broad array of diseases caused by frameshift or nonsense mutations. Our results suggest that inhibition of the rate-limiting step of NMD drives behaviors associated with pain through activation of the ISR. This work reveals complex interconnectivity between RNA stability and translational regulation and suggests an important consideration in harnessing the salubrious benefits of NMD disruption.
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Affiliation(s)
- June Bryan de la Peña
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, Wisconsin 53792
| | - Rebecca Chase
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Nikesh Kunder
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Patrick R Smith
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, Wisconsin 53792
| | - Tzu-Fang Lou
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Alexander Stanowick
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Prarthana Suresh
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Tarjani Shukla
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, Wisconsin 53792
| | - Samuel E Butcher
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53792
| | - Theodore J Price
- Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, Texas 75080
- Department of Neuroscience, University of Texas at Dallas, Richardson, Texas 75080
| | - Zachary T Campbell
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, Wisconsin 53792
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53792
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23
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Marasco LE, Kornblihtt AR. The physiology of alternative splicing. Nat Rev Mol Cell Biol 2023; 24:242-254. [PMID: 36229538 DOI: 10.1038/s41580-022-00545-z] [Citation(s) in RCA: 116] [Impact Index Per Article: 116.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2022] [Indexed: 11/09/2022]
Abstract
Alternative splicing is a substantial contributor to the high complexity of transcriptomes of multicellular eukaryotes. In this Review, we discuss the accumulated evidence that most of this complexity is reflected at the protein level and fundamentally shapes the physiology and pathology of organisms. This notion is supported not only by genome-wide analyses but, mainly, by detailed studies showing that global and gene-specific modulations of alternative splicing regulate highly diverse processes such as tissue-specific and species-specific cell differentiation, thermal regulation, neuron self-avoidance, infrared sensing, the Warburg effect, maintenance of telomere length, cancer and autism spectrum disorders (ASD). We also discuss how mastering the control of alternative splicing paved the way to clinically approved therapies for hereditary diseases.
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Affiliation(s)
- Luciano E Marasco
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Moleculary Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Alberto R Kornblihtt
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Moleculary Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina.
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24
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García-Ruiz S, Zhang D, Gustavsson EK, Rocamora-Perez G, Grant-Peters M, Fairbrother-Browne A, Reynolds RH, Brenton JW, Gil-Martínez AL, Chen Z, Rio DC, Botia JA, Guelfi S, Collado-Torres L, Ryten M. Splicing accuracy varies across human introns, tissues and age. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534370. [PMID: 37034741 PMCID: PMC10081249 DOI: 10.1101/2023.03.29.534370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Alternative splicing impacts most multi-exonic human genes. Inaccuracies during this process may have an important role in ageing and disease. Here, we investigated mis-splicing using RNA-sequencing data from ~14K control samples and 42 human body sites, focusing on split reads partially mapping to known transcripts in annotation. We show that mis-splicing occurs at different rates across introns and tissues and that these splicing inaccuracies are primarily affected by the abundance of core components of the spliceosome assembly and its regulators. Using publicly available data on short-hairpin RNA-knockdowns of numerous spliceosomal components and related regulators, we found support for the importance of RNA-binding proteins in mis-splicing. We also demonstrated that age is positively correlated with mis-splicing, and it affects genes implicated in neurodegenerative diseases. This in-depth characterisation of mis-splicing can have important implications for our understanding of the role of splicing inaccuracies in human disease and the interpretation of long-read RNA-sequencing data.
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Affiliation(s)
- S García-Ruiz
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - D Zhang
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
| | - E K Gustavsson
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - G Rocamora-Perez
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
| | - M Grant-Peters
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - A Fairbrother-Browne
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
- Department of Medical and Molecular Genetics, School of Basic and Medical Biosciences, King's College London, London, UK
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London, UK
| | - R H Reynolds
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - J W Brenton
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - A L Gil-Martínez
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London, UK
| | - Z Chen
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London, UK
| | - D C Rio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
| | - J A Botia
- Departamento de Ingeniería de la Información y las Comunicaciones, Universidad de Murcia, Murcia, Spain
| | - S Guelfi
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- Verge Genomics, South San Francisco, CA, 94080, USA
| | - L Collado-Torres
- Lieber Institute for Brain Development, Baltimore, MD, USA , 21205
| | - M Ryten
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
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25
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Bouasker S, Patel N, Greenlees R, Wellesley D, Fares Taie L, Almontashiri NA, Baptista J, Alghamdi MA, Boissel S, Martinovic J, Prokudin I, Holden S, Mudhar HS, Riley LG, Nassif C, Attie-Bitach T, Miguet M, Delous M, Ernest S, Plaisancié J, Calvas P, Rozet JM, Khan AO, Hamdan FF, Jamieson RV, Alkuraya FS, Michaud JL, Chassaing N. Bi-allelic variants in WNT7B disrupt the development of multiple organs in humans. J Med Genet 2023; 60:294-300. [PMID: 35790350 DOI: 10.1136/jmedgenet-2022-108475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 06/11/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND Pulmonary hypoplasia, Diaphragmatic anomalies, Anophthalmia/microphthalmia and Cardiac defects delineate the PDAC syndrome. We aim to identify the cause of PDAC syndrome in patients who do not carry pathogenic variants in RARB and STRA6, which have been previously associated with this disorder. METHODS We sequenced the exome of patients with unexplained PDAC syndrome and performed functional validation of candidate variants. RESULTS We identified bi-allelic variants in WNT7B in fetuses with PDAC syndrome from two unrelated families. In one family, the fetus was homozygous for the c.292C>T (p.(Arg98*)) variant whereas the fetuses from the other family were compound heterozygous for the variants c.225C>G (p.(Tyr75*)) and c.562G>A (p.(Gly188Ser)). Finally, a molecular autopsy by proxy in a consanguineous couple that lost two babies due to lung hypoplasia revealed that both parents carry the p.(Arg98*) variant. Using a WNT signalling canonical luciferase assay, we demonstrated that the identified variants are deleterious. In addition, we found that wnt7bb mutant zebrafish display a defect of the swimbladder, an air-filled organ that is a structural homolog of the mammalian lung, suggesting that the function of WNT7B has been conserved during evolution for the development of these structures. CONCLUSION Our findings indicate that defective WNT7B function underlies a form of lung hypoplasia that is associated with the PDAC syndrome, and provide evidence for involvement of the WNT-β-catenin pathway in human lung, tracheal, ocular, cardiac, and renal development.
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Affiliation(s)
- Samir Bouasker
- Research Center, University Hospital Centre Sainte-Justine, Montreal H3T 1C5, Québec, Canada
| | - Nisha Patel
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rebecca Greenlees
- Eye Genetics Research Unit, Children's Medical Research Institute, University of Sydney; The Children's Hospital at Westmead, Sydney Children's Hospitals Network; and Save Sight Institute, Sydney, New South Wales, Australia
| | - Diana Wellesley
- Wessex Clinical Genetic Service, University Hospital Southampton, Southampton, UK
| | - Lucas Fares Taie
- Laboratory Genetics in Ophthalmology, INSERM UMR1163, Imagine Institute for Genetic Diseases, Université Paris Descartes-Sorbonne, Paris, Île-de-France, France
| | - Naif A Almontashiri
- Center for Genetics and Inherited Diseases (CGID), Taibah University, Madinah, Al Madinah, Saudi Arabia.,Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Julia Baptista
- Peninsula Medical School, Faculty of Health, University of Plymouth, Plymouth, UK.,Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Malak Ali Alghamdi
- Medical Genetic Division, Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Sarah Boissel
- Research Center, University Hospital Centre Sainte-Justine, Montreal H3T 1C5, Québec, Canada
| | - Jelena Martinovic
- Unit of Fetal Pathology, APHP Hopital Antoine-Beclere, Clamart, Île-de-France, France
| | - Ivan Prokudin
- Eye Genetics Research Unit, Children's Medical Research Institute, University of Sydney; The Children's Hospital at Westmead, Sydney Children's Hospitals Network; and Save Sight Institute, Sydney, New South Wales, Australia
| | - Samantha Holden
- Department of Cellular Pathology, University Hospital Southampton, Southampton, UK
| | - Hardeep-Singh Mudhar
- National Specialist Ophthalmic Pathology Service (NSOPS), Dept of Histopathology, Royal Hallamshire Hospital, Sheffield, UK
| | - Lisa G Riley
- Rare Diseases Functional Genomics Laboratory, The Children's Hospital at Westmead, Sydney Children's Hospitals Network, Children's Medical Research Institute, University of Sydney, Sydney, New South Wales, Australia.,Specialty of Paediatrics and Child Health, Faculty of Medicine and Health, University of Sydney, Sidney, New South Wales, Australia
| | - Christina Nassif
- Research Center, University Hospital Centre Sainte-Justine, Montreal H3T 1C5, Québec, Canada
| | - Tania Attie-Bitach
- Laboratory of Embryology and Genetics of Congenital Malformations, INSERM UMR 1163, Imagine Institute for Genetic Diseases, Paris, Île-de-France, France
| | - Marguerite Miguet
- Research Center, University Hospital Centre Sainte-Justine, Montreal H3T 1C5, Québec, Canada
| | - Marion Delous
- Equipe GENDEV, Centre de Recherche en Neurosciences de Lyon, Inserm U1028, CNRS UMR5292, Université Lyon 1, Université St Etienne, Lyon, Auvergne-Rhône-Alpes, France
| | - Sylvain Ernest
- Laboratory of Embryology and Genetics of Congenital Malformations, INSERM UMR 1163, Imagine Institute for Genetic Diseases, Paris, Île-de-France, France
| | - Julie Plaisancié
- Department of Medical Genetics, Purpan University Hospital, Toulouse, Midi-Pyrénées, France.,Centre de Référence des Affections Rares en Génétique Ophtalmologique CARGO, Site Constitutif, Purpan University Hospital, Toulouse, Midi-Pyrénées, France.,INSERM U1214, ToNIC, Université Toulouse III, Toulouse, France
| | - Patrick Calvas
- Department of Medical Genetics, Purpan University Hospital, Toulouse, Midi-Pyrénées, France.,Centre de Référence des Affections Rares en Génétique Ophtalmologique CARGO, Site Constitutif, Purpan University Hospital, Toulouse, Midi-Pyrénées, France
| | - Jean-Michel Rozet
- Laboratory Genetics in Ophthalmology, INSERM UMR1163, Imagine Institute for Genetic Diseases, Université Paris Descartes-Sorbonne, Paris, Île-de-France, France
| | - Arif O Khan
- Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, Abu Dhabi, UAE
| | - Fadi F Hamdan
- Research Center, University Hospital Centre Sainte-Justine, Montreal H3T 1C5, Québec, Canada
| | - Robyn V Jamieson
- Eye Genetics Research Unit, Children's Medical Research Institute, University of Sydney; The Children's Hospital at Westmead, Sydney Children's Hospitals Network; and Save Sight Institute, Sydney, New South Wales, Australia.,Specialty of Genomic Medicine, Faculty of Medicine and Health and Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Jacques L Michaud
- Departments of Pediatrics and Neurosciences, Université de Montréal, Montreal H3T 1J4, Québec, Canada .,Departments of Pediatrics and Neurosciences, Université de Montréal, Montreal, Québec, Canada
| | - Nicolas Chassaing
- Department of Medical Genetics, Purpan University Hospital, Toulouse, Midi-Pyrénées, France .,Centre de Référence des Affections Rares en Génétique Ophtalmologique CARGO, Site Constitutif, Purpan University Hospital, Toulouse, Midi-Pyrénées, France
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26
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Louvrier C, El Khouri E, Grall Lerosey M, Quartier P, Guerrot AM, Bader Meunier B, Chican J, Mohammad M, Assrawi E, Daskalopoulou A, Arenas Garcia A, Copin B, Piterboth W, Dastot Le Moal F, Karabina SA, Amselem S, Giurgea I. De Novo Gain-Of-Function Variations in LYN Associated With an Early-Onset Systemic Autoinflammatory Disorder. Arthritis Rheumatol 2023; 75:468-474. [PMID: 36122175 DOI: 10.1002/art.42354] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 07/12/2022] [Accepted: 09/08/2022] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To identify the molecular basis of a severe systemic autoinflammatory disorder (SAID) and define its main phenotypic features, and to functionally assess the sequence variations identified in LYN, a gene encoding a nonreceptor tyrosine kinase. METHODS We used targeted next-generation sequencing and in vitro functional studies of Lyn phosphorylation state and Lyn-dependent NF-κB activity after expression of recombinant Lyn isoforms carrying different sequence variations. RESULTS We identified a de novo LYN variation (p.Tyr508His) in a patient presenting since birth with recurrent fever, chronic urticaria, atopic dermatitis, arthralgia, increased inflammatory biomarkers, and elevated plasma cytokine levels. We studied the consequences on Lyn phosphorylation state of the p.Tyr508His variation and of the 2 LYN variations reported so far (p.Tyr508Phe and p.Tyr508*), and found that all 3 variations prevent phosphorylation of residue 508 and lead to autophosphorylation of Tyr397. Additionally, these 3 LYN variations activate the NF-κB pathway. These results show a gain-of-function effect of the variations involving Tyr508 on Lyn activity. CONCLUSION This study demonstrates the pathogenicity of the first 3 LYN variations identified in SAID patients and delineates the phenotypic spectrum of a disease entity characterized by severe, early-onset, systemic inflammatory disease affecting neonates with no family history of SAID. All 3 LYN variations affect the same tyrosine residue located in the C-terminus of Lyn, thereby demonstrating the critical role of this residue in the proper regulation of Lyn activity in humans.
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Affiliation(s)
- Camille Louvrier
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, and Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
| | - Elma El Khouri
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Martine Grall Lerosey
- Département de pédiatrie et médecine de l'adolescent, CHU-Hôpitaux de Rouen, Rouen, France
| | - Pierre Quartier
- RAISE reference centre for rare diseases, Unité d'Immunologie-Hématologie et Rhumatologie pédiatrique, and Imagine Institute, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Anne-Marie Guerrot
- Université de Rouen Normandie, Inserm Unit U1245, and Rouen University Hospital, Department of Genetics and Reference Center for Developmental Disorders, and Normandy Center for Genomic and Personalized Medicine, Rouen, France
| | - Brigitte Bader Meunier
- RAISE reference centre for rare diseases, Unité d'Immunologie-Hématologie et Rhumatologie pédiatrique, and Imagine Institute, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Julie Chican
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Malaïka Mohammad
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Eman Assrawi
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Aphrodite Daskalopoulou
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Angela Arenas Garcia
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Bruno Copin
- Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
| | - William Piterboth
- Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
| | - Florence Dastot Le Moal
- Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
| | - Sonia A Karabina
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, Paris, France
| | - Serge Amselem
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, and Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
| | - Irina Giurgea
- Sorbonne Université, Inserm, Childhood Genetic Disorders, Hôpital Armand-Trousseau, and Département de Génétique médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, Paris, France
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El Younsi M, Trabelsi M, Ben Youssef S, Ouertani I, Hammi Y, Achour A, Maazoul F, Kharrat M, Gargah T, M'rad R. Clinical and genetic characteristics of Tunisian children with infantile nephropathic cystinosis. Pediatr Nephrol 2023; 38:119-129. [PMID: 35445972 DOI: 10.1007/s00467-022-05525-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Nephropathic cystinosis is an autosomal recessive disease caused by a mutation in the CTNS gene which encodes cystinosin, a lysosomal cystine transporter. The spectrum of mutations in the CTNS gene is not well defined in the North African population. Here, we investigated twelve patients with nephropathic cystinosis belonging to eight Tunisian families in order to analyze the clinical and genetic characteristics of Tunisian children with infantile nephropathic cystinosis. METHODS Clinical data were collected retrospectively. Molecular analysis of the CTNS gene was performed by Sanger sequencing. RESULTS We describe a new splicing mutation c.971-1G > C in the homozygous state in 6/12 patients which seems to be a founder mutation. The reported deletion of 23nt c.771_793 Del (p.Gly258Serfs*30) was detected in a homozygous state in one patient and in a heterozygous compound state with the c.971-1G > C mutation in 3/12 patients. Two of 12 patients have a deletion of exons 4 and 5 of the CTNS gene. None of our patients had the most common 57-kb deletion. CONCLUSIONS The mutational spectrum in the Tunisian population is different from previously described populations. Thus, a molecular diagnostic strategy must be implemented in Tunisia, by targeting as a priority the common mutations described in this country. Such a strategy will allow a cost-effective diagnosis confirmation as well as early administration of treatment with oral cysteamine. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Mariem El Younsi
- Laboratoire de Génétique Humaine, LR99ES10, Faculté de Médecine de Tunis, Université de Tunis El Manar, 1007, Tunis, Tunisia
| | - Médiha Trabelsi
- Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Sandra Ben Youssef
- Service de Pédiatrie Néphrologique Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Inès Ouertani
- Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Yousra Hammi
- Service de Pédiatrie Néphrologique Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Ahlem Achour
- Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Faouzi Maazoul
- Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Maher Kharrat
- Laboratoire de Génétique Humaine, LR99ES10, Faculté de Médecine de Tunis, Université de Tunis El Manar, 1007, Tunis, Tunisia
| | - Tahar Gargah
- Service de Pédiatrie Néphrologique Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia
| | - Ridha M'rad
- Laboratoire de Génétique Humaine, LR99ES10, Faculté de Médecine de Tunis, Université de Tunis El Manar, 1007, Tunis, Tunisia. .,Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Bab Souika, 1006, Tunis, Tunisia.
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28
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Conte MI, Poli MC, Taglialatela A, Leuzzi G, Chinn IK, Salinas SA, Rey-Jurado E, Olivares N, Veramendi-Espinoza L, Ciccia A, Lupski JR, Aldave Becerra JC, Mace EM, Orange JS. Partial loss-of-function mutations in GINS4 lead to NK cell deficiency with neutropenia. JCI Insight 2022; 7:e154948. [PMID: 36345943 PMCID: PMC9675456 DOI: 10.1172/jci.insight.154948] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 09/14/2022] [Indexed: 11/09/2022] Open
Abstract
Human NK cell deficiency (NKD) is a primary immunodeficiency in which the main clinically relevant immunological defect involves missing or dysfunctional NK cells. Here, we describe a familial NKD case in which 2 siblings had a substantive NKD and neutropenia in the absence of other immune system abnormalities. Exome sequencing identified compound heterozygous variants in Go-Ichi-Ni-San (GINS) complex subunit 4 (GINS4, also known as SLD5), an essential component of the human replicative helicase, which we demonstrate to have a damaging impact upon the expression and assembly of the GINS complex. Cells derived from affected individuals and a GINS4-knockdown cell line demonstrate delayed cell cycle progression, without signs of improper DNA synthesis or increased replication stress. By modeling partial GINS4 depletion in differentiating NK cells in vitro, we demonstrate the causal relationship between the genotype and the NK cell phenotype, as well as a cell-intrinsic defect in NK cell development. Thus, biallelic partial loss-of-function mutations in GINS4 define a potentially novel disease-causing gene underlying NKD with neutropenia. Together with the previously described mutations in other helicase genes causing NKD, and with the mild defects observed in other human cells, these variants underscore the importance of this pathway in NK cell biology.
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Affiliation(s)
- Matilde I. Conte
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, USA
| | - M. Cecilia Poli
- Faculty of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
- Immunology and Rheumatology Unit, Hospital Roberto del Rio, Santiago, Chile
| | - Angelo Taglialatela
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Giuseppe Leuzzi
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Ivan K. Chinn
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Division of Immunology, Allergy, and Retrovirology, Texas Children’s Hospital, Houston, Texas, USA
| | - Sandra A. Salinas
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Emma Rey-Jurado
- Faculty of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Nixa Olivares
- Faculty of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Liz Veramendi-Espinoza
- Allergy and Clinical Immunology, Hospital Nacional Edgardo Rebagliati Martins, Lima, Peru
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York, USA
| | - James R. Lupski
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | | | - Emily M. Mace
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, USA
| | - Jordan S. Orange
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, USA
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29
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Larionova TD, Bastola S, Aksinina TE, Anufrieva KS, Wang J, Shender VO, Andreev DE, Kovalenko TF, Arapidi GP, Shnaider PV, Kazakova AN, Latyshev YA, Tatarskiy VV, Shtil AA, Moreau P, Giraud F, Li C, Wang Y, Rubtsova MP, Dontsova OA, Condro M, Ellingson BM, Shakhparonov MI, Kornblum HI, Nakano I, Pavlyukov MS. Alternative RNA splicing modulates ribosomal composition and determines the spatial phenotype of glioblastoma cells. Nat Cell Biol 2022; 24:1541-1557. [PMID: 36192632 PMCID: PMC10026424 DOI: 10.1038/s41556-022-00994-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/15/2022] [Indexed: 02/08/2023]
Abstract
Glioblastoma (GBM) is characterized by exceptionally high intratumoral heterogeneity. However, the molecular mechanisms underlying the origin of different GBM cell populations remain unclear. Here, we found that the compositions of ribosomes of GBM cells in the tumour core and edge differ due to alternative RNA splicing. The acidic pH in the core switches before messenger RNA splicing of the ribosomal gene RPL22L1 towards the RPL22L1b isoform. This allows cells to survive acidosis, increases stemness and correlates with worse patient outcome. Mechanistically, RPL22L1b promotes RNA splicing by interacting with lncMALAT1 in the nucleus and inducing its degradation. Contrarily, in the tumour edge region, RPL22L1a interacts with ribosomes in the cytoplasm and upregulates the translation of multiple messenger RNAs including TP53. We found that the RPL22L1 isoform switch is regulated by SRSF4 and identified a compound that inhibits this process and decreases tumour growth. These findings demonstrate how distinct GBM cell populations arise during tumour growth. Targeting this mechanism may decrease GBM heterogeneity and facilitate therapy.
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Affiliation(s)
- Tatyana D Larionova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Soniya Bastola
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Tatiana E Aksinina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Ksenia S Anufrieva
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Jia Wang
- Department of Neurosurgery, Centre of Brain Science, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Victoria O Shender
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Dmitriy E Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Tatiana F Kovalenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
| | - Georgij P Arapidi
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Polina V Shnaider
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Anastasia N Kazakova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency, Moscow, Russian Federation
| | - Yaroslav A Latyshev
- N.N. Burdenko National Medical Research Center of Neurosurgery, Ministry of Health of the Russian Federation, Moscow, Russian Federation
| | - Victor V Tatarskiy
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Alexander A Shtil
- Blokhin National Medical Research Center of Oncology, Moscow, Russian Federation
| | - Pascale Moreau
- Institute of Chemistry of Clermont-Ferrand, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Francis Giraud
- Institute of Chemistry of Clermont-Ferrand, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Chaoxi Li
- Department of Neurosurgery, School of Medicine and O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yichan Wang
- Department of Neurosurgery, Centre of Brain Science, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Maria P Rubtsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Olga A Dontsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russian Federation
| | - Michael Condro
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Benjamin M Ellingson
- Brain Tumor Imaging Laboratory, Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles, Los Angeles, CA, USA
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Harley I Kornblum
- Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Ichiro Nakano
- Department of Neurosurgery, Medical Institute of Hokuto, Hokkaido, Japan.
| | - Marat S Pavlyukov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russian Federation.
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
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30
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Genetic modulation of anemia severity, hemolysis level, and hospitalization rate in Angolan children with Sickle Cell Anemia. Mol Biol Rep 2022; 49:10347-10356. [PMID: 36097125 DOI: 10.1007/s11033-022-07831-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Sickle Cell Anemia (SCA) is a genetic disease caused by the c.20 A > T mutation in HBB gene, generally characterized by sickle erythrocytes, chronic hemolytic anemia, and vaso-occlusive events. This study aimed to investigate genetic modulators of anemia severity, chronic hemolytic rate, and clinical manifestations in pediatric SCA patients from Angola, where the disease is a severe public health problem. METHODS AND RESULTS The study was conducted on 200 SCA children living in Luanda or Caxito province. Their clinical phenotype was collected from patients' hospital records. Hematological and biochemical phenotypes were characterized in steady state condition. Twelve polymorphic regions in VCAM1, CD36 and NOS3 genes were genotyped using PCR, RFLP, and Sanger sequencing. CD36 gene promoter variants showed a significant impact on anemia severity. Particularly, the rs1413661_C allele was associated with lower hemoglobin levels, and increased number of hospitalizations and transfusions. This is the first report associating this SNP with SCA phenotypic heterogeneity. Moreover, the rs1041163_C allele in VCAM1 was associated with lower LDH levels; inversely the rs2070744_C allele in NOS3 was related with higher LDH levels and number of hospitalizations, being a risk factor for increased hemolytic rate. CONCLUSION This study highlights, for the first time in the Angolan population, the importance of the genetic modifiers of vascular cell adhesion and nitric oxide metabolism in SCA pediatric phenotypic variability.
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31
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Bowling A, Eastman A, Merlo C, Lin G, West N, Patel S, Cutting G, Sharma N. Downstream Alternate Start Site Allows N-Terminal Nonsense Variants to Escape NMD and Results in Functional Recovery by Readthrough and Modulator Combination. J Pers Med 2022; 12:jpm12091448. [PMID: 36143233 PMCID: PMC9504986 DOI: 10.3390/jpm12091448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/26/2022] [Accepted: 08/31/2022] [Indexed: 11/23/2022] Open
Abstract
Genetic variants that introduce premature termination codons (PTCs) have remained difficult to therapeutically target due to lack of protein product. Nonsense mediated mRNA decay (NMD) targets PTC-bearing transcripts to reduce the potentially damaging effects of truncated proteins. Readthrough compounds have been tested on PTC-generating variants in attempt to permit translation through a premature stop. However, readthrough compounds have not proved efficacious in a clinical setting due to lack of stable mRNA. Here, we investigate N-terminal variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which have been shown to escape NMD, potentially through a mechanism of alternative translation initiation at downstream AUG codons. We hypothesized that N-terminal variants in CFTR that evade NMD will produce stable transcript, allowing CFTR function to be restored by a combination of readthrough and protein modulator therapy. We investigate this using two cell line models expressing CFTR-expression minigenes (EMG; HEK293s and CFBEs) and primary human nasal epithelial (NE) cells, and we test readthrough compounds G418 and ELX-02 in combination with CFTR protein modulators. HEK293 cells expressing the variants E60X and L88X generate CFTR-specific core glycosylated products that are consistent with downstream translation initiation. Mutation of downstream methionines at codons 150 and 152 does not result in changes in CFTR protein processing in cells expressing L88X-CFTR-EMG. However, mutation of methionine at 265 results in loss of detectable CFTR protein in cells expressing E60X, L88X, and Y122X CFTR-EMGs, indicating that downstream translation initiation is occurring at the AUG codon at position M265. In HEK293 stable cells harboring L88X, treatment with readthrough compounds alone allows for formation of full-length, but misfolded CFTR protein. Upon addition of protein modulators in combination with readthrough, we observe formation of mature, complex-glycosylated CFTR. In CFBE and NE cells, addition of readthrough ELX-02 and modulator therapy results in substantial recovery of CFTR function. Our work indicates that N-terminal variants generate stable CFTR transcript due to translation initiation at a downstream AUG codon. Thus, individuals with CF bearing 5′ nonsense variants that evade NMD are ideal candidates for treatment with clinically safe readthrough compounds and modulator therapy.
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Affiliation(s)
- Alyssa Bowling
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alice Eastman
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christian Merlo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Gabrielle Lin
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natalie West
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Shivani Patel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Garry Cutting
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Neeraj Sharma
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Correspondence:
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Fanelli A, Marconato L, Licenziato L, Minoli L, Rouquet N, Aresu L. POT1 mutations are frequent and associated with Ki-67 index in canine diffuse large B-cell lymphoma. Front Vet Sci 2022; 9:968807. [PMID: 36016811 PMCID: PMC9396242 DOI: 10.3389/fvets.2022.968807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Diffuse large B-cell lymphoma (DLBCL) represents one of the most frequent and deadliest neoplasia in dogs worldwide and is characterized by a remarkable degree of clinical heterogeneity, with poor chances to anticipate the outcome. Even if in the last years some recurrently mutated genes have been identified, the genetic origin of canine DLBCL (cDLBCL) is not yet completely understood. The aim of the present study was to assess the prevalence of POT1 mutations in cDLBCL and to elucidate the role of such gene in the pathogenesis of this tumor. Mutations in POT1 were retrieved in 34% of cases, in line with previous reports, but no significant associations with any clinico-pathological variable were identified. Likewise, POT1 mutations are not predictive of worse prognosis. Interestingly, Ki-67 index was significantly higher in dogs harboring POT1 mutations compared to wild-type ones. These results suggest that POT1 mutations may exert their pathogenic role in cDLBCL by promoting cellular proliferation.
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Affiliation(s)
- Antonella Fanelli
- Department of Veterinary Sciences, University of Turin, Turin, Italy
- *Correspondence: Antonella Fanelli
| | - Laura Marconato
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Luca Licenziato
- Department of Veterinary Sciences, University of Turin, Turin, Italy
| | - Lucia Minoli
- Department of Veterinary Sciences, University of Turin, Turin, Italy
| | | | - Luca Aresu
- Department of Veterinary Sciences, University of Turin, Turin, Italy
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33
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Tan K, Stupack DG, Wilkinson MF. Nonsense-mediated RNA decay: an emerging modulator of malignancy. Nat Rev Cancer 2022; 22:437-451. [PMID: 35624152 PMCID: PMC11009036 DOI: 10.1038/s41568-022-00481-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 12/11/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved RNA turnover pathway that selectively degrades RNAs harbouring truncating mutations that prematurely terminate translation, including nonsense, frameshift and some splice-site mutations. Recent studies show that NMD shapes the mutational landscape of tumours by selecting for mutations that tend to downregulate the expression of tumour suppressor genes but not oncogenes. This suggests that NMD can benefit tumours, a notion further supported by the finding that mRNAs encoding immunogenic neoantigen peptides are typically targeted for decay by NMD. Together, this raises the possibility that NMD-inhibitory therapy could be of therapeutic benefit against many tumour types, including those with a high load of neoantigen-generating mutations. Complicating this scenario is the evidence that NMD can also be detrimental for many tumour types, and consequently tumours often have perturbed NMD. NMD may suppress tumour generation and progression by degrading subsets of specific normal mRNAs, including those encoding stress-response proteins, signalling factors and other proteins beneficial for tumours, as well as pro-tumour non-coding RNAs. Together, these findings suggest that NMD-modulatory therapy has the potential to provide widespread therapeutic benefit against diverse tumour types. However, whether NMD should be stimulated or repressed requires careful analysis of the tumour to be treated.
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Affiliation(s)
- Kun Tan
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Dwayne G Stupack
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- UCSD Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
| | - Miles F Wilkinson
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
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Retinal Proteomic Alterations and Combined Transcriptomic-Proteomic Analysis in the Early Stages of Progression of a Mouse Model of X-Linked Retinoschisis. Cells 2022; 11:cells11142150. [PMID: 35883593 PMCID: PMC9321393 DOI: 10.3390/cells11142150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022] Open
Abstract
X-linked retinoschisis (XLRS) is among the most commonly inherited degenerative retinopathies. XLRS is caused by functional impairment of RS1. However, the molecular mechanisms underlying RS1 malfunction remain largely uncharacterized. Here, we performed a data-independent acquisition-mass spectrometry-based proteomic analysis in RS1-null mouse retina with different postal days (Ps), including the onset (P15) and early progression stage (P56). Gene set enrichment analysis showed that type I interferon-mediated signaling was upregulated and photoreceptor proteins responsible for detection of light stimuli were downregulated at P15. Positive regulation of Tor signaling was downregulated and nuclear transcribed mRNA catabolic process nonsense-mediated decay was upregulated at P56. Moreover, the differentially expressed proteins at P15 were enriched in metabolism of RNA and RNA destabilization. A broader subcellular localization distribution and enriched proteins in visual perception and phototransduction were evident at P56. Combined transcriptomic-proteomic analysis revealed that functional impairments, including detection of visible light, visual perception, and visual phototransduction, occurred at P21 and continued until P56. Our work provides insights into the molecular mechanisms underlying the onset and progression of an XLRS mouse model during the early stages, thus enhancing the understanding of the mechanism of XLRS.
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35
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The G3BP1-UPF1-Associated Long Non-Coding RNA CALA Regulates RNA Turnover in the Cytoplasm. Noncoding RNA 2022; 8:ncrna8040049. [PMID: 35893232 PMCID: PMC9326601 DOI: 10.3390/ncrna8040049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/10/2022] [Accepted: 06/28/2022] [Indexed: 11/16/2022] Open
Abstract
Besides transcription, RNA decay accounts for a large proportion of regulated gene expression and is paramount for cellular functions. Classical RNA surveillance pathways, like nonsense-mediated decay (NMD), are also implicated in the turnover of non-mutant transcripts. Whereas numerous protein factors have been assigned to distinct RNA decay pathways, the contribution of long non-coding RNAs (lncRNAs) to RNA turnover remains unknown. Here we identify the lncRNA CALA as a potent regulator of RNA turnover in endothelial cells. We demonstrate that CALA forms cytoplasmic ribonucleoprotein complexes with G3BP1 and regulates endothelial cell functions. A detailed characterization of these G3BP1-positive complexes by mass spectrometry identifies UPF1 and numerous other NMD factors having cytoplasmic G3BP1-association that is CALA-dependent. Importantly, CALA silencing impairs degradation of NMD target transcripts, establishing CALA as a non-coding regulator of RNA steady-state levels in the endothelium.
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36
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Elton TS, Hernandez VA, Carvajal-Moreno J, Wang X, Ipinmoroti D, Yalowich JC. Intronic Polyadenylation in Acquired Cancer Drug Resistance Circumvented by Utilizing CRISPR/Cas9 with Homology-Directed Repair: The Tale of Human DNA Topoisomerase IIα. Cancers (Basel) 2022; 14:cancers14133148. [PMID: 35804920 PMCID: PMC9265003 DOI: 10.3390/cancers14133148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
Simple Summary DNA topoisomerase IIα (170 kDa, TOP2α/170) resolves nucleic acid topological entanglements by generating transient double-strand DNA breaks. TOP2α inhibitors/poisons stabilize TOP2α-DNA covalent complexes resulting in persistent DNA damage and are frequently utilized to treat a variety of cancers. Acquired resistance to these chemotherapeutic agents is often associated with decreased TOP2α/170 expression levels. Studies have demonstrated that a reduction in TOP2α/170 results from a type of alternative polyadenylation designated intronic polyadenylation (IPA). As a consequence of IPA, variant TOP2α mRNA transcripts have been characterized that have resulted in the translation of C-terminal truncated TOP2α isoforms with altered biological activities. In this paper, an example is discussed where circumvention of acquired TOP2α-mediated drug resistance was achieved by utilizing CRISPR/Cas9 specific gene editing of an exon/intron boundary through homology directed repair (HDR) to reduce TOP2α IPA. These results illustrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant IPA. Abstract Intronic polyadenylation (IPA) plays a critical role in malignant transformation, development, progression, and cancer chemoresistance by contributing to transcriptome/proteome alterations. DNA topoisomerase IIα (170 kDa, TOP2α/170) is an established clinical target for anticancer agents whose efficacy is compromised by drug resistance often associated with a reduction of nuclear TOP2α/170 levels. In leukemia cell lines with acquired resistance to TOP2α-targeted drugs and reduced TOP2α/170 expression, variant TOP2α mRNA transcripts have been reported due to IPA that resulted in the translation of C-terminal truncated isoforms with altered nuclear-cytoplasmic distribution or heterodimerization with wild-type TOP2α/170. This review provides an overview of the various mechanisms regulating pre-mRNA processing and alternative polyadenylation, as well as the utilization of CRISPR/Cas9 specific gene editing through homology directed repair (HDR) to decrease IPA when splice sites are intrinsically weak or potentially mutated. The specific case of TOP2α exon 19/intron 19 splice site editing is discussed in etoposide-resistant human leukemia K562 cells as a tractable strategy to circumvent acquired TOP2α-mediated drug resistance. This example supports the importance of aberrant IPA in acquired drug resistance to TOP2α-targeted drugs. In addition, these results demonstrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant splicing/polyadenylation.
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Ensinck MM, Carlon MS. One Size Does Not Fit All: The Past, Present and Future of Cystic Fibrosis Causal Therapies. Cells 2022; 11:cells11121868. [PMID: 35740997 PMCID: PMC9220995 DOI: 10.3390/cells11121868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/25/2022] [Accepted: 05/28/2022] [Indexed: 02/04/2023] Open
Abstract
Cystic fibrosis (CF) is the most common monogenic disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Over the last 30 years, tremendous progress has been made in understanding the molecular basis of CF and the development of treatments that target the underlying defects in CF. Currently, a highly effective CFTR modulator treatment (Kalydeco™/Trikafta™) is available for 90% of people with CF. In this review, we will give an extensive overview of past and ongoing efforts in the development of therapies targeting the molecular defects in CF. We will discuss strategies targeting the CFTR protein (i.e., CFTR modulators such as correctors and potentiators), its cellular environment (i.e., proteostasis modulation, stabilization at the plasma membrane), the CFTR mRNA (i.e., amplifiers, nonsense mediated mRNA decay suppressors, translational readthrough inducing drugs) or the CFTR gene (gene therapies). Finally, we will focus on how these efforts can be applied to the 15% of people with CF for whom no causal therapy is available yet.
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Affiliation(s)
- Marjolein M. Ensinck
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
| | - Marianne S. Carlon
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Flanders, Belgium
- Correspondence:
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Stoica C, Ferreira AK, Hannan K, Bakovic M. Bilayer Forming Phospholipids as Targets for Cancer Therapy. Int J Mol Sci 2022; 23:ijms23095266. [PMID: 35563655 PMCID: PMC9100777 DOI: 10.3390/ijms23095266] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/28/2022] [Accepted: 05/02/2022] [Indexed: 12/15/2022] Open
Abstract
Phospholipids represent a crucial component for the structure of cell membranes. Phosphatidylcholine and phosphatidylethanolamine are two phospholipids that comprise the majority of cell membranes. De novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine occurs via the Kennedy pathway, and perturbations in the regulation of this pathway are linked to a variety of human diseases, including cancer. Altered phosphatidylcholine and phosphatidylethanolamine membrane content, phospholipid metabolite levels, and fatty acid profiles are frequently identified as hallmarks of cancer development and progression. This review summarizes the research on how phospholipid metabolism changes over oncogenic transformation, and how phospholipid profiling can differentiate between human cancer and healthy tissues, with a focus on colorectal cancer, breast cancer, and non-small cell lung cancer. The potential for phospholipids to serve as biomarkers for diagnostics, or as anticancer therapy targets, is also discussed.
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Affiliation(s)
- Celine Stoica
- Department of Human Health and Nutritional Science, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada; (C.S.); (K.H.)
| | - Adilson Kleber Ferreira
- Department of Immunology, Laboratory of Tumor Immunology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil;
- Department of Oncology, Alchemypet—Veterinary Dignostic Medicine, São Paulo 05024-000, Brazil
| | - Kayleigh Hannan
- Department of Human Health and Nutritional Science, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada; (C.S.); (K.H.)
| | - Marica Bakovic
- Department of Human Health and Nutritional Science, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada; (C.S.); (K.H.)
- Correspondence:
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The Genetic and Molecular Analyses of RAD51C and RAD51D Identifies Rare Variants Implicated in Hereditary Ovarian Cancer from a Genetically Unique Population. Cancers (Basel) 2022; 14:cancers14092251. [PMID: 35565380 PMCID: PMC9104874 DOI: 10.3390/cancers14092251] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
To identify candidate variants in RAD51C and RAD51D ovarian cancer (OC) predisposing genes by investigating French Canadians (FC) exhibiting unique genetic architecture. Candidates were identified by whole exome sequencing analysis of 17 OC families and 53 early-onset OC cases. Carrier frequencies were determined by the genetic analysis of 100 OC or HBOC families, 438 sporadic OC cases and 1025 controls. Variants of unknown function were assayed for their biological impact and/or cellular sensitivity to olaparib. RAD51C c.414G>C;p.Leu138Phe and c.705G>T;p.Lys235Asn and RAD51D c.137C>G;p.Ser46Cys, c.620C>T;p.Ser207Leu and c.694C>T;p.Arg232Ter were identified in 17.6% of families and 11.3% of early-onset cases. The highest carrier frequency was observed in OC families (1/44, 2.3%) and sporadic cases (15/438, 3.4%) harbouring RAD51D c.620C>T versus controls (1/1025, 0.1%). Carriers of c.620C>T (n = 7), c.705G>T (n = 2) and c.137C>G (n = 1) were identified in another 538 FC OC cases. RAD51C c.705G>T affected splicing by skipping exon four, while RAD51D p.Ser46Cys affected protein stability and conferred olaparib sensitivity. Genetic and functional assays implicate RAD51C c.705G>T and RAD51D c.137C>G as likely pathogenic variants in OC. The high carrier frequency of RAD51D c.620C>T in FC OC cases validates previous findings. Our findings further support the role of RAD51C and RAD51D in hereditary OC.
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Alenezi WM, Fierheller CT, Revil T, Serruya C, Mes-Masson AM, Foulkes WD, Provencher D, El Haffaf Z, Ragoussis J, Tonin PN. Case Review: Whole-Exome Sequencing Analyses Identify Carriers of a Known Likely Pathogenic Intronic BRCA1 Variant in Ovarian Cancer Cases Clinically Negative for Pathogenic BRCA1 and BRCA2 Variants. Genes (Basel) 2022; 13:genes13040697. [PMID: 35456503 PMCID: PMC9032308 DOI: 10.3390/genes13040697] [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: 03/08/2022] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 12/04/2022] Open
Abstract
Background: Detecting pathogenic intronic variants resulting in aberrant splicing remains a challenge in routine genetic testing. We describe germline whole-exome sequencing (WES) analyses and apply in silico predictive tools of familial ovarian cancer (OC) cases reported clinically negative for pathogenic BRCA1 and BRCA2 variants. Methods: WES data from 27 familial OC cases reported clinically negative for pathogenic BRCA1 and BRCA2 variants and 53 sporadic early-onset OC cases were analyzed for pathogenic variants in BRCA1 or BRCA2. WES data from carriers of pathogenic BRCA1 or BRCA2 variants were analyzed for pathogenic variants in 10 other OC predisposing genes. Loss of heterozygosity analysis was performed on tumor DNA from variant carriers. Results: BRCA1 c.5407-25T>A intronic variant, identified in two affected sisters and one sporadic OC case, is predicted to create a new splice effecting transcription of BRCA1. WES data from BRCA1 c.5407-25T>A carriers showed no evidence of pathogenic variants in other OC predisposing genes. Sequencing the tumor DNA from the variant carrier showed complete loss of the wild-type allele. Conclusions: The findings support BRCA1 c.5407-25T>A as a likely pathogenic variant and highlight the importance of investigating intronic sequences as causal variants in OC families where the involvement of BRCA1 is highly suggestive.
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Affiliation(s)
- Wejdan M. Alenezi
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- Cancer Research Program, Centre for Translational Biology, The Research Institute of McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
- Department of Medical Laboratory Technology, Taibah University, Medina 42353, Saudi Arabia
| | - Caitlin T. Fierheller
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- Cancer Research Program, Centre for Translational Biology, The Research Institute of McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
| | - Timothée Revil
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- McGill Genome Centre, McGill University, Montreal, QC H3A 0G1, Canada
| | - Corinne Serruya
- Cancer Research Program, Centre for Translational Biology, The Research Institute of McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
| | - Anne-Marie Mes-Masson
- Département de Médecine, Université de Montréal, Montreal, QC H3T 1J4, Canada;
- Institut du Cancer de Montréal, Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montreal, QC H2X 0A9, Canada; (D.P.); (Z.E.H.)
| | - William D. Foulkes
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- Cancer Research Program, Centre for Translational Biology, The Research Institute of McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
- Lady Davis Institute for Medical Research of the Jewish General Hospital, Montreal, QC H3T 1E2, Canada
- Department of Medical Genetics, McGill University Health Centre, Montreal, QC H3H 1P3, Canada
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 1G5, Canada
| | - Diane Provencher
- Institut du Cancer de Montréal, Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montreal, QC H2X 0A9, Canada; (D.P.); (Z.E.H.)
- Division of Gynecologic Oncology, Université de Montréal, Montreal, QC H4A 3J1, Canada
| | - Zaki El Haffaf
- Institut du Cancer de Montréal, Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montreal, QC H2X 0A9, Canada; (D.P.); (Z.E.H.)
- Service de Médecine Génique, Centre Hospitalier de l’Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jiannis Ragoussis
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- McGill Genome Centre, McGill University, Montreal, QC H3A 0G1, Canada
| | - Patricia N. Tonin
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; (W.M.A.); (C.T.F.); (T.R.); (W.D.F.); (J.R.)
- Cancer Research Program, Centre for Translational Biology, The Research Institute of McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
- Correspondence: ; Tel.: +1-(514)-934-1934 (ext. 44069)
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A Quality Control Mechanism of Splice Site Selection Abrogated under Stress and in Cancer. Cancers (Basel) 2022; 14:cancers14071750. [PMID: 35406522 PMCID: PMC8996931 DOI: 10.3390/cancers14071750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/14/2022] [Accepted: 03/28/2022] [Indexed: 12/26/2022] Open
Abstract
Simple Summary Splicing and alternative splicing play a major role in regulating gene expression, and mis-regulation of splicing can lead to several diseases, including cancer. The aim of this review is to summarize the current knowledge of a quality control mechanism of splice site selection termed Suppression of Splicing (SOS), proposed to protect cells from splicing at the numerous intronic unused 5′ splice sites, and emphasize its relevance to cancer. This relevance stems from the finding that SOS is abrogated under stress and in cancer resulting in the expression of thousands of aberrant nonsense mRNAs that may be toxic to cells. These findings highlight the unexplored potential of such aberrant isoforms as novel targets for cancer diagnosis and therapies. Abstract Latent 5’ splice sites, highly abundant in human introns, are not normally used. This led to the proposal of a quality control mechanism, Suppression of Splicing (SOS), which protects cells from splicing at the numerous intronic latent sites, and whose activation can generate nonsense mRNAs. SOS was shown to be independent of Nonsense-Mediated mRNA Decay (NMD). Efforts to decipher the SOS mechanism revealed a pivotal role for initiator-tRNA, independent of protein translation. Recently, nucleolin (a multifunctional protein) was found to directly and specifically bind the initiator-tRNA in the nucleus and was shown to be a protein component of SOS, enabling an updated model of the SOS mechanism. Importantly, SOS is abrogated under stress and in cancer (e.g., in breast cancer cells and gliomas), generating thousands of nonsense mRNAs due to activation of latent splicing. The resulting affected human genes cover a variety of functional groups, including genes involved in cell proliferation and differentiation. Furthermore, in oligodendroglioma, the extent of activation of latent splicing increases with the severity of the cancer. Interesting examples are genes expressing aberrant nonsense mRNAs in both breast cancer and glioma, due to latent splicing activation. These findings highlight the unexplored potential of such aberrant isoforms as novel targets for cancer diagnosis and therapies.
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Qi Y, Ji X, Ding H, Liu L, Zhang Y, Yin A. Novel Biallelic Variant in the BRAT1 Gene Caused Nonprogressive Cerebellar Ataxia Syndrome. Front Genet 2022; 13:821587. [PMID: 35360849 PMCID: PMC8960271 DOI: 10.3389/fgene.2022.821587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 01/07/2022] [Indexed: 01/13/2023] Open
Abstract
Recessive mutations in BRAT1 cause lethal neonatal rigidity and multifocal seizure syndrome (RMFSL), a phenotype characterized by neonatal microcephaly, hypertonia, and refractory epilepsy with premature death. Recently, attenuated disease variants have been described, suggesting that a wider clinical spectrum of BRAT1-associated neurodegeneration exists than was previously thought. Here, we reported a 10-year-old girl with severe intellectual disability, rigidity, ataxia or dyspraxia, and cerebellar atrophy on brain MRI; two BRAT1 variants in the trans configuration [c.1014A > C (p.Pro338 = ); c.706delC (p.Leu236Cysfs*5)] were detected using whole-exome sequencing. RNA-seq confirmed significantly decreased BRAT1 transcript levels in the presence of the variant; further, it revealed an intron retention between exon 7 and exon 8 caused by the synonymous base substitute. Subsequent prenatal diagnosis for these two variants guided the parents to reproduce. We expand the phenotypic spectrum of BRAT1-associated disorders by first reporting the pathogenic synonymous variant of the BRAT1 gene, resulting in clinical severity that is mild compared to the severe phenotype seen in RMFSL. Making an accurate diagnosis and prognostic evaluation of BRAT1-associated neurodegeneration is important for reproductive consultation and disease management.
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Affiliation(s)
- Yiming Qi
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Xueqi Ji
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Clinical Medicine College, Guangzhou Medical University, Guangzhou, China
| | - Hongke Ding
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Liu
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Yan Zhang
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Aihua Yin
- Prenatal Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, China,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, China,Clinical Medicine College, Guangzhou Medical University, Guangzhou, China,*Correspondence: Aihua Yin,
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Zhao J, Li Z, Puri R, Liu K, Nunez I, Chen L, Zheng S. Molecular profiling of individual FDA-approved clinical drugs identifies modulators of nonsense-mediated mRNA decay. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:304-318. [PMID: 35024243 PMCID: PMC8718828 DOI: 10.1016/j.omtn.2021.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) degrades transcripts with premature stop codons. Given the prevalence of nonsense single nucleotide polymorphisms (SNPs) in the general population, it is urgent to catalog the effects of clinically approved drugs on NMD activity: any interference could alter the expression of nonsense SNPs, inadvertently inducing adverse effects. This risk is higher for patients with disease-causing nonsense mutations or an illness linked to dysregulated nonsense transcripts. On the other hand, hundreds of disorders are affected by cellular NMD efficiency and may benefit from NMD-modulatory drugs. Here, we profiled individual FDA-approved drugs for their impact on cellular NMD efficiency using a sensitive method that directly probes multiple endogenous NMD targets for a robust readout of NMD modulation. We found most FDA-approved drugs cause unremarkable effects on NMD, while many elicit clear transcriptional responses. Besides several potential mild NMD modulators, the anticancer drug homoharringtonine (HHT or omacetaxine mepesuccinate) consistently upregulates various endogenous NMD substrates in a dose-dependent manner in multiple cell types. We further showed translation inhibition mediates HHT's NMD effect. In summary, many FDA drugs induce transcriptional changes, and a few impact global NMD, and direct measurement of endogenous NMD substrate expression is robust to monitor cellular NMD.
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Affiliation(s)
- Jingrong Zhao
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Zhelin Li
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Ruchira Puri
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Kelvin Liu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Israel Nunez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Liang Chen
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sika Zheng
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
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The profile of expression of the scaffold protein SG2NA(s) differs between cancer types and its interactome in normal vis-a-vis breast tumor tissues suggests its wide roles in regulating multiple cellular pathways. Mol Cell Biochem 2022; 477:1653-1668. [PMID: 35230605 DOI: 10.1007/s11010-022-04401-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/18/2022] [Indexed: 10/19/2022]
Abstract
Striatin and SG2NA are scaffold proteins that form signaling complexes called STRIPAK. It has been associated with developmental abnormalities, cancer, and several other diseases. Our earlier studies have shown that SG2NA forms a complex with the cancer-associated protein DJ-1 and the signaling kinase Akt, promoting cancer cell survival. In the present study, we used bioinformatics analyses to confirm the existence of two isoforms of human SG2NA, i.e., 78 and 87 kDas. In addition, several smaller isoforms like 35 kDa were also seen in western blot analyses of human cell lysates. The expression of these isoforms varies between different cancer cell lines of human origin. Also, the protein levels do not corroborate with its transcript levels, suggesting a complex regulation of its expression. In breast tumor tissues, the expression of the 35 and 78 kDa isoforms was higher as compared to the adjacent normal tissues, while the 87 kDa isoform was found in the breast tumor tissues only. With the progression of stages of breast cancer, while the expression of 78 kDa isoform decreased, 87 kDa became undetectable. In co-immunoprecipitation assays, the profile of the SG2NA interactome in breast tumors vis-à-vis adjacent normal breast tissues showed hundreds of common proteins. Also, some proteins were interacted with SG2NA in breast tumor tissues only. We conclude that SG2NA is involved in diverse cellular pathways and has roles in cellular reprogramming during tumorigenesis of the breast.
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Donor Splice Site Variant in SLC9A6 Causes Christianson Syndrome in a Lithuanian Family: A Case Report. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58030351. [PMID: 35334527 PMCID: PMC8949093 DOI: 10.3390/medicina58030351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 11/16/2022]
Abstract
Background and Objectives: The pathogenic variants of SLC9A6 are a known cause of a rare, X-linked neurological disorder called Christianson syndrome (CS). The main characteristics of CS are developmental delay, intellectual disability, and neurological findings. This study investigated the genetic basis and explored the molecular changes that led to CS in two male siblings presenting with intellectual disability, epilepsy, behavioural problems, gastrointestinal dysfunction, poor height, and weight gain. Materials and Methods: Next-generation sequencing of a tetrad was applied to identify the DNA changes and Sanger sequencing of proband’s cDNA was used to evaluate the impact of a splice site variant on mRNA structure. Bioinformatical tools were used to investigate SLC9A6 protein structure changes. Results: Sequencing and bioinformatical analysis revealed a novel donor splice site variant (NC_000023.11(NM_001042537.1):c.899 + 1G > A) that leads to a frameshift and a premature stop codon. Protein structure modelling showed that the truncated protein is unlikely to form any functionally relevant SLC9A6 dimers. Conclusions: Molecular and bioinformatical analysis revealed the impact of a novel donor splice site variant in the SLC9A6 gene that leads to truncated and functionally disrupted protein causing the phenotype of CS in the affected individuals.
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Jin JY, Zhang LY, Guo S, Tang K, Zeng L, Xiang R, Liang JY. Genetic analysis combined with 3D-printing assistant surgery in diagnosis and treatment for an X-linked hypophosphatemia patient. J Clin Lab Anal 2022; 36:e24243. [PMID: 35106857 PMCID: PMC8906030 DOI: 10.1002/jcla.24243] [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: 10/14/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 11/05/2022] Open
Abstract
Background Hypophosphatemia is mainly characterized by hypophosphatemia and a low level of 1alpha,25‐Dihydroxyvitamin D2 (1,25‐(OH)2D2) and/or 1alpha,25‐Dihydroxyvitamin D3 (1,25‐(OH)2D3) in the blood. Previous studies have demonstrated that variants in PHEX and FGF23 are primarily responsible for this disease. Although patients with variants of these two genes share almost the same symptoms, they exhibit the different hereditary pattern, X‐link dominant and autosome dominant, respectively. Three‐dimensional (3D) printing is a method which can accurately reconstruct physical objects, and its applications in orthopedics can contribute to realizing a more accurate surgical performance and a better outcome. Methods An X‐linked hypophosphatemia (XLH) family was recruited, with four patients across three generations. We screened candidate genes and filtered a duplication variant in PHEX. Variant analysis and co‐segregation confirmation were then performed. Before the operation of our patient, a digital model of our patient's leg had been rebuilt upon the CT scan data, and a polylactic acid (PLA) model had been 3D‐printed. Results A novel duplication PHEX variant c.574dupG (p.A192GfsX20) was identified in a family with XLH. Its pathogenicity was confirmed by the co‐segregation assay and online bioinformatics database. The preoperative plan was made with the help of the PLA model. Then, arch osteotomy and transverse osteotomy were performed under the guidance of the previous simulation. The appearance of the surgical‐intervened leg was satisfactory. Conclusions This study identified a novel PHEX variant and showed that 3D printing tech is a very promising approach for corrective osteotomies.
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Affiliation(s)
- Jie-Yuan Jin
- Department of Orthopaedics, Xiangya Hospital of Central South University, Changsha, China.,School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, China
| | - Li-Yang Zhang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Shuai Guo
- School of Life Sciences, Central South University, Changsha, China
| | - Ke Tang
- School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Lei Zeng
- Department of Orthopaedics, Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Rong Xiang
- Department of Orthopaedics, Xiangya Hospital of Central South University, Changsha, China.,School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Jie-Yu Liang
- Department of Orthopaedics, Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
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47
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Zhang K, Tarczykowska A, Gupta DK, Pendlebury DF, Zuckerman C, Nandakumar J, Shibuya H. The TERB1 MYB domain suppresses telomere erosion in meiotic prophase I. Cell Rep 2022; 38:110289. [PMID: 35081355 PMCID: PMC8867601 DOI: 10.1016/j.celrep.2021.110289] [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: 06/21/2021] [Revised: 11/08/2021] [Accepted: 12/29/2021] [Indexed: 11/24/2022] Open
Abstract
The meiosis-specific telomere-binding protein TERB1 anchors telomeres to the nuclear envelope and drives chromosome movements for the pairing of homologous chromosomes. TERB1 has an MYB-like DNA-binding (MYB) domain, which is a hallmark of telomeric DNA-binding proteins. Here, we demonstrate that the TERB1 MYB domain has lost its canonical DNA-binding activity. The analysis of Terb1 point mutant mice expressing TERB1 lacking its MYB domain showed that the MYB domain is dispensable for telomere localization of TERB1 and the downstream TERB2-MAJIN complex, the promotion of homologous pairing, and even fertility. Instead, the TERB1 MYB domain regulates the enrichment of cohesin and promotes the remodeling of axial elements in the early-to-late pachytene transition, which suppresses telomere erosion. Considering its conservation across metazoan phyla, the TERB1 MYB domain is likely to be important for the maintenance of telomeric DNA and thus for genomic integrity by suppressing meiotic telomere erosion over long evolutionary timescales.
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Affiliation(s)
- Kexin Zhang
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg SE-41390, Sweden
| | - Agata Tarczykowska
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg SE-41390, Sweden
| | - Deepesh Kumar Gupta
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg SE-41390, Sweden
| | - Devon F Pendlebury
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Cassandra Zuckerman
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hiroki Shibuya
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg SE-41390, Sweden.
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Yang P, Broadbent R, Prasad C, Levin S, Goobie S, Knoll JH, Prasad AN. De novo STXBP1 Mutations in Two Patients With Developmental Delay With or Without Epileptic Seizures. Front Neurol 2022; 12:804078. [PMID: 35002943 PMCID: PMC8739808 DOI: 10.3389/fneur.2021.804078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/29/2021] [Indexed: 12/03/2022] Open
Abstract
Objectives: Mutations in the STXBP1 gene have been associated with epileptic encephalopathy. Previous studies from in vitro neuroblastoma 2A cells showed that haploinsufficiency of STXBP1 is the mechanism for epileptic encephalopathy. In this ex vivo study, STXPB1 DNA mutations and RNA expression were assessed from two patients to help understand the impact of STXBP1 mutations on the disease etiology and mechanism. Methods: Microarray analysis and DNA sequencing were performed on two children with development delay, one with and one without infantile spasms. Different pathogenic mutations of STXBP1 were identified in the patients and RNA expression of STXPB1 was then performed by RT-Q-PCR on RNA extracted from blood samples of each patient. Results: Pathogenic deletion [of exons 13–20 and 3′ downstream of STXBP1] and nonsense mutation [c.1663G>T (p.Glu555X) in exon 18 of STXBP1] were detected from the two patients, respectively. RNA analysis showed that 1) the deletion mediated RNA decay, and that 2) no RNA decay was identified for the nonsense mutation at codon 555 which predicts a truncated STXBP1 protein. Significance: Our RNA expression analyses from the patient blood samples are the first ex vivo studies to support that both haploinsufficiency and truncation of STXBP1 protein (either dominant negative or haploinsufficiency) are causative mechanisms for epileptic encephalopathies, intellectual disability and developmental delay. The RNA assay also suggests that escape from nonsense-mediated RNA decay is possible when the nonsense mutation resides <50 nucleotides upstream of the last coding exon-exon junction even in the presence of additional non-coding exons that are 3′ downstream of the last coding exon.
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Affiliation(s)
- Ping Yang
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Robert Broadbent
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Chitra Prasad
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
| | - Simon Levin
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
| | - Sharan Goobie
- Maritime Medical Genetic Service, Department of Paediatrics, Izaak Walton Killam Health Centre, Halifax, NS, Canada
| | - Joan H Knoll
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Asuri N Prasad
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
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49
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Vallverdú-Prats M, Brugada R, Alcalde M. Premature Termination Codon in 5' Region of Desmoplakin and Plakoglobin Genes May Escape Nonsense-Mediated Decay through the Reinitiation of Translation. Int J Mol Sci 2022; 23:ijms23020656. [PMID: 35054841 PMCID: PMC8775493 DOI: 10.3390/ijms23020656] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 02/04/2023] Open
Abstract
Arrhythmogenic cardiomyopathy is a heritable heart disease associated with desmosomal mutations, especially premature termination codon (PTC) variants. It is known that PTC triggers the nonsense-mediated decay (NMD) mechanism. It is also accepted that PTC in the last exon escapes NMD; however, the mechanisms involving NMD escaping in 5′-PTC, such as reinitiation of translation, are less known. The main objective of the present study is to evaluate the likelihood that desmosomal genes carrying 5′-PTC will trigger reinitiation. HL1 cell lines were edited by CRISPR/Cas9 to generate isogenic clones carrying 5′-PTC for each of the five desmosomal genes. The genomic context of the ATG in-frame in the 5′ region of desmosomal genes was evaluated by in silico predictions. The expression levels of the edited genes were assessed by Western blot and real-time PCR. Our results indicate that the 5′-PTC in PKP2, DSG2 and DSC2 acts as a null allele with no expression, whereas in the DSP and JUP gene, N-truncated protein is expressed. In concordance with this, the genomic context of the 5′-region of DSP and JUP presents an ATG in-frame with an optimal context for the reinitiation of translation. Thus, 5′-PTC triggers NMD in the PKP2, DSG2* and DSC2 genes, whereas it may escape NMD through the reinitiation of the translation in DSP and JUP genes, with no major effects on ACM-related gene expression.
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Affiliation(s)
| | - Ramon Brugada
- Cardiovascular Genetics Center, IdIBGi, University of Girona, 17190 Girona, Spain;
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain
- Cardiology Service Hospital, University of Girona, 17007 Girona, Spain
- Correspondence: (R.B.); (M.A.)
| | - Mireia Alcalde
- Cardiovascular Genetics Center, IdIBGi, University of Girona, 17190 Girona, Spain;
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Correspondence: (R.B.); (M.A.)
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50
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Wang D, Dong X, Xiong Y, Li Z, Xie Y, Liang S, Huang T. Identification of a novel TBX5 c.755 + 1 G > A variant and related pathogenesis in a family with Holt-Oram syndrome. Am J Med Genet A 2022; 188:58-70. [PMID: 34490705 PMCID: PMC9290998 DOI: 10.1002/ajmg.a.62488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/03/2021] [Accepted: 08/18/2021] [Indexed: 02/05/2023]
Abstract
The proband with congenital heart disease and abnormal thumb was clinically diagnosed as Holt-Oram syndrome (HOS). A novel variant, T-box transcription factor 5 (TBX5) c.755 + 1 G > A, was identified in the proband via whole exome sequencing and validated using Sanger sequencing. Pedigree analysis and clinical examinations revealed three/seven individuals over three generations within the family, with features suggestive of HOS. Deep amplicon sequencing confirmed that the allele frequencies of the novel variant in the proband (III-1), her brother (III-2), and her mother (II-2) were 50%, 48.3%, and 38.1%, respectively, indicating that III-1 and III-2 harbored heterozygous variants, while II-2 harbored mosaic heterozygous variants. The minigene splicing assay showed that the novel variant affected the normal splicing of exon 7, resulting in the production of abnormal TBX5 transcripts. Reverse transcription-quantitative polymerase chain reaction and western blot analyses revealed that the novel variant upregulated TBX5 expression at the transcriptional and translational levels. Nuclear localization assay demonstrated impaired nuclear localization of the mutant TBX5. Cell viability assay revealed the inhibition of cell activity by the mutant TBX5. Our findings indicate that the novel variant was potentially induced HOS, probably by causing aberrant splicing, reducing the enrichment of nuclear TBX5 protein, and inhibiting cellular proliferation.
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Affiliation(s)
- De‐Gang Wang
- Research Center for Reproductive Medicine, Shantou University Medical College, Shantou, China
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Xing‐Sheng Dong
- Prenatal Diagnosis CenterBoai Hospital of ZhongshanZhongshanChina
| | - Yi Xiong
- Prenatal Diagnosis CenterBoai Hospital of ZhongshanZhongshanChina
- The Second School of Clinical Medicine, Southern Medical UniversityGuangzhouChina
| | - Zhi‐Ming Li
- Prenatal Diagnosis CenterBoai Hospital of ZhongshanZhongshanChina
| | - Ying‐Jun Xie
- Department of Obstetrics and Gynecology, Key Laboratory for Major Obstetric Diseases of Guangdong ProvinceThe Third Affiliated Hospital of Guangzhou Medical UniversityGuangzhouChina
| | - Shu‐Hua Liang
- The Second School of Clinical Medicine, Southern Medical UniversityGuangzhouChina
| | - Tian‐Hua Huang
- Research Center for Reproductive Medicine, Shantou University Medical College, Shantou, China
- Chengdu Jinxin Research Institute for Reproductive Medicine and Genetics, Chengdu, China
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