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Ritter AJ, Wallace A, Ronaghi N, Sanford J. junctionCounts: comprehensive alternative splicing analysis and prediction of isoform-level impacts to the coding sequence. NAR Genom Bioinform 2024; 6:lqae093. [PMID: 39131822 PMCID: PMC11310779 DOI: 10.1093/nargab/lqae093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 07/15/2024] [Accepted: 07/22/2024] [Indexed: 08/13/2024] Open
Abstract
Alternative splicing (AS) is emerging as an important regulatory process for complex biological processes. Transcriptomic studies therefore commonly involve the identification and quantification of alternative processing events, but the need for predicting the functional consequences of changes to the relative inclusion of alternative events remains largely unaddressed. Many tools exist for the former task, albeit each constrained to its own event type definitions. Few tools exist for the latter task; each with significant limitations. To address these issues we developed junctionCounts, which captures both simple and complex pairwise AS events and quantifies them with straightforward exon-exon and exon-intron junction reads in RNA-seq data, performing competitively among similar tools in terms of sensitivity, false discovery rate and quantification accuracy. Its partner utility, cdsInsertion, identifies transcript coding sequence (CDS) information via in silico translation from annotated start codons, including the presence of premature termination codons. Finally, findSwitchEvents connects AS events with CDS information to predict the impact of individual events to the isoform-level CDS. We used junctionCounts to characterize splicing dynamics and NMD regulation during neuronal differentiation across four primates, demonstrating junctionCounts' capacity to robustly characterize AS in a variety of organisms and to predict its effect on mRNA isoform fate.
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Affiliation(s)
- Alexander J Ritter
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrew Wallace
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Neda Ronaghi
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Jeremy R Sanford
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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2
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Sauer B, Lorenz NI, Divé I, Klann K, Luger AL, Urban H, Schröder JH, Steinbach JP, Münch C, Ronellenfitsch MW. Mammalian target of rapamycin inhibition protects glioma cells from temozolomide-induced cell death. Cell Death Discov 2024; 10:8. [PMID: 38182566 PMCID: PMC10770336 DOI: 10.1038/s41420-023-01779-2] [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: 05/19/2023] [Revised: 11/30/2023] [Accepted: 12/14/2023] [Indexed: 01/07/2024] Open
Abstract
Glioblastoma is an incurable brain tumor with a median survival below two years. Trials investigating targeted therapy with inhibitors of the kinase mTOR have produced ambiguous results. Especially combination of mTOR inhibition with standard temozolomide radiochemotherapy has resulted in reduced survival in a phase II clinical trial. To date, this phenomenon is only poorly understood. To recreate the therapeutic setting in vitro, we exposed glioblastoma cell lines to co-treatment with rapamycin and temozolomide and assessed cell viability, DNA damage and reactive oxygen species. Additionally, we employed a novel translatomic based mass spectrometry approach ("mePROD") to analyze acute changes in translated proteins. mTOR inhibition with rapamycin protected glioblastoma cells from temozolomide toxicity. Following co-treatment of temozolomide with rapamycin, an increased translation of reactive oxygen species (ROS)-detoxifying proteins was detected by mass spectrometry. This was accompanied by improved ROS-homeostasis and reduced DNA damage. Additionally, rapamycin induced the expression of the DNA repair enzyme O-6-methylguanine-DNA methyltransferase (MGMT) in glioblastoma cells with an unmethylated MGMT gene promotor. Inhibition of mTOR antagonized the cytotoxic effects of temozolomide in vitro. The induction of antioxidant defences and MGMT are two underlying candidate mechanisms. Further functional experiments in vitro and in vivo are warranted to characterize this effect that appears relevant for combinatorial therapeutic strategies.
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Affiliation(s)
- Benedikt Sauer
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- Institute of Biochemistry II, Goethe University, Frankfurt am Main, Germany
| | - Nadja I Lorenz
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
| | - Iris Divé
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- Institute of Biochemistry II, Goethe University, Frankfurt am Main, Germany
| | - Kevin Klann
- Institute of Biochemistry II, Goethe University, Frankfurt am Main, Germany
- Cardio-Pulmonary Institute, Frankfurt am Main, Germany
| | - Anna-Luisa Luger
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Hans Urban
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Jan-Hendrik Schröder
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
| | - Joachim P Steinbach
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Christian Münch
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- Institute of Biochemistry II, Goethe University, Frankfurt am Main, Germany
- Cardio-Pulmonary Institute, Frankfurt am Main, Germany
| | - Michael W Ronellenfitsch
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany.
- University Cancer Center Frankfurt (UCT), Frankfurt am Main, Germany.
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, a partnership between DKFZ and University Hospital Frankfurt, Frankfurt am Main, Germany.
- Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany.
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3
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Wittenstein A, Caspi M, Rippin I, Elroy-Stein O, Eldar-Finkelman H, Thoms S, Rosin-Arbesfeld R. Nonsense mutation suppression is enhanced by targeting different stages of the protein synthesis process. PLoS Biol 2023; 21:e3002355. [PMID: 37943958 PMCID: PMC10684085 DOI: 10.1371/journal.pbio.3002355] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/28/2023] [Accepted: 09/29/2023] [Indexed: 11/12/2023] Open
Abstract
The introduction of premature termination codons (PTCs), as a result of splicing defects, insertions, deletions, or point mutations (also termed nonsense mutations), lead to numerous genetic diseases, ranging from rare neuro-metabolic disorders to relatively common inheritable cancer syndromes and muscular dystrophies. Over the years, a large number of studies have demonstrated that certain antibiotics and other synthetic molecules can act as PTC suppressors by inducing readthrough of nonsense mutations, thereby restoring the expression of full-length proteins. Unfortunately, most PTC readthrough-inducing agents are toxic, have limited effects, and cannot be used for therapeutic purposes. Thus, further efforts are required to improve the clinical outcome of nonsense mutation suppressors. Here, by focusing on enhancing readthrough of pathogenic nonsense mutations in the adenomatous polyposis coli (APC) tumor suppressor gene, we show that disturbing the protein translation initiation complex, as well as targeting other stages of the protein translation machinery, enhances both antibiotic and non-antibiotic-mediated readthrough of nonsense mutations. These findings strongly increase our understanding of the mechanisms involved in nonsense mutation readthrough and facilitate the development of novel therapeutic targets for nonsense suppression to restore protein expression from a large variety of disease-causing mutated transcripts.
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Affiliation(s)
- Amnon Wittenstein
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ido Rippin
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Orna Elroy-Stein
- Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Hagit Eldar-Finkelman
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sven Thoms
- Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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4
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Jackson CA, Beheler-Amass M, Tjärnberg A, Suresh I, Hickey ASM, Bonneau R, Gresham D. Simultaneous estimation of gene regulatory network structure and RNA kinetics from single cell gene expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.21.558277. [PMID: 37790443 PMCID: PMC10542544 DOI: 10.1101/2023.09.21.558277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Cells respond to environmental and developmental stimuli by remodeling their transcriptomes through regulation of both mRNA transcription and mRNA decay. A central goal of biology is identifying the global set of regulatory relationships between factors that control mRNA production and degradation and their target transcripts and construct a predictive model of gene expression. Regulatory relationships are typically identified using transcriptome measurements and causal inference algorithms. RNA kinetic parameters are determined experimentally by employing run-on or metabolic labeling (e.g. 4-thiouracil) methods that allow transcription and decay rates to be separately measured. Here, we develop a deep learning model, trained with single-cell RNA-seq data, that both infers causal regulatory relationships and estimates RNA kinetic parameters. The resulting in silico model predicts future gene expression states and can be perturbed to simulate the effect of transcription factor changes. We acquired model training data by sequencing the transcriptomes of 175,000 individual Saccharomyces cerevisiae cells that were subject to an external perturbation and continuously sampled over a one hour period. The rate of change for each transcript was calculated on a per-cell basis to estimate RNA velocity. We then trained a deep learning model with transcriptome and RNA velocity data to calculate time-dependent estimates of mRNA production and decay rates. By separating RNA velocity into transcription and decay rates, we show that rapamycin treatment causes existing ribosomal protein transcripts to be rapidly destabilized, while production of new transcripts gradually slows over the course of an hour. The neural network framework we present is designed to explicitly model causal regulatory relationships between transcription factors and their genes, and shows superior performance to existing models on the basis of recovery of known regulatory relationships. We validated the predictive power of the model by perturbing transcription factors in silico and comparing transcriptome-wide effects with experimental data. Our study represents the first step in constructing a complete, predictive, biophysical model of gene expression regulation.
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Affiliation(s)
- Christopher A Jackson
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | - Maggie Beheler-Amass
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | - Andreas Tjärnberg
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | - Ina Suresh
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | - Angela Shang-mei Hickey
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | | | - David Gresham
- Center For Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
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5
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Stoeger T, Grant RA, McQuattie-Pimentel AC, Anekalla KR, Liu SS, Tejedor-Navarro H, Singer BD, Abdala-Valencia H, Schwake M, Tetreault MP, Perlman H, Balch WE, Chandel NS, Ridge KM, Sznajder JI, Morimoto RI, Misharin AV, Budinger GRS, Nunes Amaral LA. Aging is associated with a systemic length-associated transcriptome imbalance. NATURE AGING 2022; 2:1191-1206. [PMID: 37118543 PMCID: PMC10154227 DOI: 10.1038/s43587-022-00317-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 10/21/2022] [Indexed: 12/14/2022]
Abstract
Aging is among the most important risk factors for morbidity and mortality. To contribute toward a molecular understanding of aging, we analyzed age-resolved transcriptomic data from multiple studies. Here, we show that transcript length alone explains most transcriptional changes observed with aging in mice and humans. We present three lines of evidence supporting the biological importance of the uncovered transcriptome imbalance. First, in vertebrates the length association primarily displays a lower relative abundance of long transcripts in aging. Second, eight antiaging interventions of the Interventions Testing Program of the National Institute on Aging can counter this length association. Third, we find that in humans and mice the genes with the longest transcripts enrich for genes reported to extend lifespan, whereas those with the shortest transcripts enrich for genes reported to shorten lifespan. Our study opens fundamental questions on aging and the organization of transcriptomes.
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Affiliation(s)
- Thomas Stoeger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL, USA.
- Center for Genetic Medicine, Northwestern University, Evanston, IL, USA.
| | - Rogan A Grant
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
| | | | - Kishore R Anekalla
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
| | - Sophia S Liu
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | | | - Benjamin D Singer
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA
- Department of Biochemistry and Molecular Genetics, Northwestern University, Evanston, IL, USA
| | - Hiam Abdala-Valencia
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
| | - Michael Schwake
- Department of Neurology, Northwestern University, Evanston, IL, USA
- Faculty of Chemistry, University of Bielefeld, Bielefeld, Germany
| | - Marie-Pier Tetreault
- Division of Gastroenterology and Hepatology, Northwestern University, Evanston, IL, USA
| | - Harris Perlman
- Division of Rheumatology, Northwestern University, Evanston, IL, USA
| | | | - Navdeep S Chandel
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA
| | - Karen M Ridge
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA
| | - Richard I Morimoto
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
- Rice Institute for Biomedical Research, Northwestern University, Evanston, IL, USA.
| | - Alexander V Misharin
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA.
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA.
| | - G R Scott Budinger
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Evanston, IL, USA.
- Simpson Querrey Lung Institute for Translational Science at Northwestern University (SQLIFTSNU), Evanston, IL, USA.
| | - Luis A Nunes Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.
- Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL, USA.
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA.
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6
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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: 49] [Impact Index Per Article: 24.5] [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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7
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Leitner DF, Kanshin E, Askenazi M, Siu Y, Friedman D, Devore S, Jones D, Ueberheide B, Wisniewski T, Devinsky O. Pilot study evaluating everolimus molecular mechanisms in tuberous sclerosis complex and focal cortical dysplasia. PLoS One 2022; 17:e0268597. [PMID: 35587487 PMCID: PMC9119437 DOI: 10.1371/journal.pone.0268597] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/02/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) and some focal cortical dysplasias (FCDs) are associated with dysfunctional mTOR signaling, resulting in increased cell growth and ribosomal S6 protein phosphorylation (phospho-S6). mTOR inhibitors can reduce TSC tumor growth and seizure frequency, and preclinical FCD studies indicate seizure suppression. This pilot study evaluated safety of mTOR inhibitor everolimus in treatment resistant (failure of >2 anti-seizure medications) TSC and FCD patients undergoing surgical resection and to assess mTOR signaling and molecular pathways. METHODS AND FINDINGS We evaluated everolimus in 14 treatment resistant epilepsy patients undergoing surgical resection (4.5 mg/m2 daily for 7 days; n = 4 Active, mean age 18.3 years, range 4-26; n = 10, Control, mean age 13.1, range 3-45). Everolimus was well tolerated. Mean plasma everolimus in Active participants were in target range (12.4 ng/ml). Brain phospho-S6 was similar in Active and Control participants with a lower trend in Active participants, with Ser235/236 1.19-fold (p = 0.67) and Ser240/244 1.15-fold lower (p = 0.66). Histologically, Ser235/236 was 1.56-fold (p = 0.37) and Ser240/244 was 5.55-fold lower (p = 0.22). Brain proteomics identified 11 proteins at <15% false discovery rate associated with coagulation system (p = 1.45x10-9) and acute phase response (p = 1.23x10-6) activation. A weighted gene correlation network analysis (WGCNA) of brain proteomics and phospho-S6 identified 5 significant modules. Higher phospho-S6 correlated negatively with cellular respiration and synaptic transmission and positively with organophosphate metabolic process, nuclear mRNA catabolic process, and neuron ensheathment. Brain metabolomics identified 14 increased features in Active participants, including N-acetylaspartylglutamic acid. Plasma proteomics and cytokine analyses revealed no differences. CONCLUSIONS Short-term everolimus before epilepsy surgery in TSC and FCD resulted in no adverse events and trending lower mTOR signaling (phospho-S6). Future studies should evaluate implications of our findings, including coagulation system activation and everolimus efficacy in FCD, in larger studies with long-term treatment to better understand molecular and clinical effects. CLINICAL TRIALS REGISTRATION ClinicalTrials.gov NCT02451696.
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Affiliation(s)
- Dominique F. Leitner
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, New York, United States of America
| | - Evgeny Kanshin
- Proteomics Laboratory, Division of Advanced Research Technologies, NYU School of Medicine, New York, New York, United States of America
| | - Manor Askenazi
- Biomedical Hosting LLC, Arlington, Massachusetts, United States of America
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Yik Siu
- Metabolomics Core Resource Laboratory, New York University School of Medicine, New York, New York, United States of America
| | - Daniel Friedman
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, New York, United States of America
| | - Sasha Devore
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, New York, United States of America
| | - Drew Jones
- Metabolomics Core Resource Laboratory, New York University School of Medicine, New York, New York, United States of America
| | - Beatrix Ueberheide
- Proteomics Laboratory, Division of Advanced Research Technologies, NYU School of Medicine, New York, New York, United States of America
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
- Center for Cognitive Neurology, Department of Neurology, New York University School of Medicine, New York, New York, United States of America
| | - Thomas Wisniewski
- Center for Cognitive Neurology, Department of Neurology, New York University School of Medicine, New York, New York, United States of America
- Department of Psychiatry, New York University School of Medicine, New York, New York, United States of America
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, New York, United States of America
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8
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Fritz SE, Ranganathan S, Wang CD, Hogg JR. An alternative UPF1 isoform drives conditional remodeling of nonsense-mediated mRNA decay. EMBO J 2022; 41:e108898. [PMID: 35403729 PMCID: PMC9108617 DOI: 10.15252/embj.2021108898] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/18/2022] [Accepted: 03/25/2022] [Indexed: 12/11/2022] Open
Abstract
The nonsense-mediated mRNA decay (NMD) pathway monitors translation termination in order to degrade transcripts with premature stop codons and regulate thousands of human genes. Here, we show that an alternative mammalian-specific isoform of the core NMD factor UPF1, termed UPF1LL , enables condition-dependent remodeling of NMD specificity. Previous studies indicate that the extension of a conserved regulatory loop in the UPF1LL helicase core confers a decreased propensity to dissociate from RNA upon ATP hydrolysis relative to UPF1SL , the major UPF1 isoform. Using biochemical and transcriptome-wide approaches, we find that UPF1LL can circumvent the protective RNA binding proteins PTBP1 and hnRNP L to preferentially bind and down-regulate transcripts with long 3'UTRs normally shielded from NMD. Unexpectedly, UPF1LL supports induction of NMD on new populations of substrate mRNAs in response to activation of the integrated stress response and impaired translation efficiency. Thus, while canonical NMD is abolished by moderate translational repression, UPF1LL activity is enhanced, offering the possibility to rapidly rewire NMD specificity in response to cellular stress.
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Affiliation(s)
- Sarah E Fritz
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Soumya Ranganathan
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Clara D Wang
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - J Robert Hogg
- Biochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMDUSA
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9
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Page R, Scourfield E, Ficarelli M, McKellar SW, Lee KL, Maguire TJ, Bouton C, Lista MJ, Neil SJ, Malim MH, Zuckerman M, Mischo HE, Martinez-Nunez RT. Homebrew: An economical and sensitive glassmilk-based nucleic-acid extraction method for SARS-CoV-2 diagnostics. CELL REPORTS METHODS 2022; 2:100186. [PMID: 35262039 PMCID: PMC8890991 DOI: 10.1016/j.crmeth.2022.100186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/26/2021] [Accepted: 02/25/2022] [Indexed: 12/22/2022]
Abstract
Management of COVID-19 and other epidemics requires large-scale diagnostic testing. The gold standard for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains reverse transcription quantitative PCR (qRT-PCR) analysis, which detects viral RNA more sensitively than any other method. However, the resource use and supply-chain requirements of RT-PCR have continued to challenge diagnostic laboratories worldwide. Here, we establish and characterize a low-cost method to detect SARS-CoV-2 in clinical combined nose and throat swabs, allowing for automation in high-throughput settings. This method inactivates virus material with sodium dodecylsulfate (SDS) and uses silicon dioxide as the RNA-binding matrix in combination with sodium chloride (NaCl) and isopropanol. With similar sensitivity for SARS-CoV-2 viral targets but a fraction of time and reagent expenditure compared with commercial kits, our method also enables sample pooling without loss of sensitivity. We suggest that this method will facilitate more economical widespread testing, particularly in resource-limited settings.
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Affiliation(s)
- Robert Page
- ImmunoEngineering Lab, School of Cancer and Pharmaceutical Sciences, King's College London, Guy's Cancer Centre, Great Maze Pond, London SE1 9RT, UK
| | - Edward Scourfield
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Mattia Ficarelli
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Stuart W. McKellar
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Kwok Leung Lee
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Thomas J.A. Maguire
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Clement Bouton
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Maria Jose Lista
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Stuart J.D. Neil
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Michael H. Malim
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Mark Zuckerman
- South London Specialist Virology Centre, King’s College Hospital London, London, UK
| | - Hannah E. Mischo
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
| | - Rocio T. Martinez-Nunez
- Department Infectious Diseases, School of Immunology and Microbial Sciences, Guy’s Campus, King’s College London, London SE1 9RT, UK
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10
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Dalal JS, Winden KD, Salussolia CL, Sundberg M, Singh A, Pham TT, Zhou P, Pu WT, Miller MT, Sahin M. Loss of Tsc1 in cerebellar Purkinje cells induces transcriptional and translation changes in FMRP target transcripts. eLife 2021; 10:e67399. [PMID: 34259631 PMCID: PMC8279760 DOI: 10.7554/elife.67399] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/29/2021] [Indexed: 12/19/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder that is associated with multiple neurological manifestations. Previously, we demonstrated that Tsc1 loss in cerebellar Purkinje cells (PCs) can cause altered social behavior in mice. Here, we performed detailed transcriptional and translational analyses of Tsc1-deficient PCs to understand the molecular alterations in these cells. We found that target transcripts of the Fragile X Mental Retardation Protein (FMRP) are reduced in mutant PCs with evidence of increased degradation. Surprisingly, we observed unchanged ribosomal binding for many of these genes using translating ribosome affinity purification. Finally, we found that multiple FMRP targets, including SHANK2, were reduced, suggesting that compensatory increases in ribosomal binding efficiency may be unable to overcome reduced transcript levels. These data further implicate dysfunction of FMRP and its targets in TSC and suggest that treatments aimed at restoring the function of these pathways may be beneficial.
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Affiliation(s)
- Jasbir Singh Dalal
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Kellen Diamond Winden
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Catherine Lourdes Salussolia
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Maria Sundberg
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Achint Singh
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Truc Thanh Pham
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Pingzhu Zhou
- Department of Cardiology, Boston Children’s HospitalBostonUnited States
| | - William T Pu
- Department of Cardiology, Boston Children’s HospitalBostonUnited States
- Harvard Medical SchoolBostonUnited States
| | - Meghan T Miller
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center BaselBaselSwitzerland
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
- Harvard Medical SchoolBostonUnited States
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11
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Systematic Analysis of Targets of Pumilio-Mediated mRNA Decay Reveals that PUM1 Repression by DNA Damage Activates Translesion Synthesis. Cell Rep 2021; 31:107542. [PMID: 32375027 DOI: 10.1016/j.celrep.2020.107542] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/28/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023] Open
Abstract
RNA-binding proteins (RBPs) play a pivotal role in gene expression by modulating the stability of transcripts. However, the identification of degradation target mRNAs of RBPs remains difficult. By the combined analysis of transcriptome-wide mRNA stabilities and the binding of mRNAs to human Pumilio 1 (PUM1), we identify 48 mRNAs that both bind to PUM1 and exhibit PUM1-dependent degradation. Analysis of changes in the abundance of PUM1 and its degradation target mRNAs in RNA-seq data indicate that DNA-damaging agents negatively regulate PUM1-mediated mRNA decay. Cells exposed to cisplatin have reduced PUM1 abundance and increased PCNA and UBE2A mRNAs encoding proteins involved in DNA damage tolerance by translesion synthesis (TLS). Cells overexpressing PUM1 exhibit impaired DNA synthesis and TLS and increased sensitivity to the cytotoxic effect of cisplatin. Thus, our method identifies target mRNAs of PUM1-mediated decay and reveals that cells respond to DNA damage by inhibiting PUM1-mediated mRNA decay to activate TLS.
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12
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Tang HW, Weng JH, Lee WX, Hu Y, Gu L, Cho S, Lee G, Binari R, Li C, Cheng ME, Kim AR, Xu J, Shen Z, Xu C, Asara JM, Blenis J, Perrimon N. mTORC1-chaperonin CCT signaling regulates m 6A RNA methylation to suppress autophagy. Proc Natl Acad Sci U S A 2021; 118:e2021945118. [PMID: 33649236 PMCID: PMC7958400 DOI: 10.1073/pnas.2021945118] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mechanistic Target of Rapamycin Complex 1 (mTORC1) is a central regulator of cell growth and metabolism that senses and integrates nutritional and environmental cues with cellular responses. Recent studies have revealed critical roles of mTORC1 in RNA biogenesis and processing. Here, we find that the m6A methyltransferase complex (MTC) is a downstream effector of mTORC1 during autophagy in Drosophila and human cells. Furthermore, we show that the Chaperonin Containing Tailless complex polypeptide 1 (CCT) complex, which facilitates protein folding, acts as a link between mTORC1 and MTC. The mTORC1 activates the chaperonin CCT complex to stabilize MTC, thereby increasing m6A levels on the messenger RNAs encoding autophagy-related genes, leading to their degradation and suppression of autophagy. Altogether, our study reveals an evolutionarily conserved mechanism linking mTORC1 signaling with m6A RNA methylation and demonstrates their roles in suppressing autophagy.
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Affiliation(s)
- Hong-Wen Tang
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore 169857, Singapore;
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Jui-Hsia Weng
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
| | - Wen Xing Lee
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Lei Gu
- Division of Newborn Medicine and Epigenetics Program, Department of Medicine, Boston Children's Hospital, Boston, MA 02115
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Sungyun Cho
- Department of Pharmacology, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065
| | - Gina Lee
- Department of Pharmacology, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065
- Department of Microbiology and Molecular Genetics, Chao Family Comprehensive Cancer Center, University of California Irvine School of Medicine, Irvine, CA 92697
| | - Richard Binari
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Cathleen Li
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Min En Cheng
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Ah-Ram Kim
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Jun Xu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Zhangfei Shen
- Division of Newborn Medicine and Epigenetics Program, Department of Medicine, Boston Children's Hospital, Boston, MA 02115
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Chiwei Xu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115
- Department of Medicine, Harvard Medical School, Boston, MA 02115
| | - John Blenis
- Department of Pharmacology, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115;
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115
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13
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Yatsuka H, Hada K, Shiraishi H, Umeda R, Morisaki I, Urushibata H, Shimizu N, Sebastian WA, Hikida T, Ishitani T, Hanada R, Shimada T, Kimoto K, Kubota T, Hanada T. Exosc2 deficiency leads to developmental disorders by causing a nucleotide pool imbalance in zebrafish. Biochem Biophys Res Commun 2020; 533:1470-1476. [PMID: 33333712 DOI: 10.1016/j.bbrc.2020.10.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023]
Abstract
Exosc2 is one of the components of the exosome complex involved in RNA 3' end processing and degradation of various RNAs. Recently, EXOSC2 mutation has been reported in German families presenting short stature, hearing loss, retinitis pigmentosa, and premature aging. However, the in vivo function of EXOSC2 has been elusive. Herein, we generated Exosc2 knockout (exosc2-/-) zebrafish that showed larval lethality 13 days post fertilization, with microcephaly, loss of spinal motor neurons, myelin deficiency, and retinitis pigmentosa. Mechanistically, Exosc2 deficiency caused impaired mRNA turnover, resulting in a nucleotide pool imbalance. Rapamycin, which modulated mRNA turnover by inhibiting the mTOR pathway, improved nucleotide pool imbalance in exosc2-/- zebrafish, resulting in prolonged survival and partial rescue of neuronal defects. Taken together, our findings offer new insights into the disease pathogenesis caused by Exosc2 deficiency, and might help explain fundamental molecular mechanisms in neuronal diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis, and spinal muscular atrophy.
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Affiliation(s)
- Hiroyuki Yatsuka
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Kazumasa Hada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hiroshi Shiraishi
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Ryohei Umeda
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Ikuko Morisaki
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hirotaro Urushibata
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Nobuyuki Shimizu
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Wulan Apridita Sebastian
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Tohru Ishitani
- Department of Homeostatic Regulation, Division of Cellular and Molecular Biology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Reiko Hanada
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Tatsuo Shimada
- Oita Medical Technology School, Japan College of Judo-Therapy, Acupuncture & Moxibustion Therapy, Oita, Japan
| | - Kenichi Kimoto
- Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshiaki Kubota
- Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshikatsu Hanada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan.
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14
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Halloy F, Iyer P, Ćwiek P, Ghidini A, Barman-Aksözen J, Wildner-Verhey van Wijk N, Theocharides APA, Minder E, Schneider-Yin X, Schümperli D, Hall J. Delivery of oligonucleotides to bone marrow to modulate ferrochelatase splicing in a mouse model of erythropoietic protoporphyria. Nucleic Acids Res 2020; 48:4658-4671. [PMID: 32313951 PMCID: PMC7229840 DOI: 10.1093/nar/gkaa229] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/25/2020] [Accepted: 04/09/2020] [Indexed: 12/17/2022] Open
Abstract
Erythropoietic protoporphyria (EPP) is a rare genetic disease in which patients experience acute phototoxic reactions after sunlight exposure. It is caused by a deficiency in ferrochelatase (FECH) in the heme biosynthesis pathway. Most patients exhibit a loss-of-function mutation in trans to an allele bearing a SNP that favors aberrant splicing of transcripts. One viable strategy for EPP is to deploy splice-switching oligonucleotides (SSOs) to increase FECH synthesis, whereby an increase of a few percent would provide therapeutic benefit. However, successful application of SSOs in bone marrow cells is not described. Here, we show that SSOs comprising methoxyethyl-chemistry increase FECH levels in cells. We conjugated one SSO to three prototypical targeting groups and administered them to a mouse model of EPP in order to study their biodistribution, their metabolic stability and their FECH splice-switching ability. The SSOs exhibited distinct distribution profiles, with increased accumulation in liver, kidney, bone marrow and lung. However, they also underwent substantial metabolism, mainly at their linker groups. An SSO bearing a cholesteryl group increased levels of correctly spliced FECH transcript by 80% in the bone marrow. The results provide a promising approach to treat EPP and other disorders originating from splicing dysregulation in the bone marrow.
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Affiliation(s)
- François Halloy
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Pavithra S Iyer
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Paulina Ćwiek
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Alice Ghidini
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | | | | | - Alexandre P A Theocharides
- Department of Medical Oncology and Hematology, University Hospital and University of Zurich, Zurich, Switzerland
| | | | | | - Daniel Schümperli
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Jonathan Hall
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
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15
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Identifying the Translatome of Mouse NEBD-Stage Oocytes via SSP-Profiling; A Novel Polysome Fractionation Method. Int J Mol Sci 2020; 21:ijms21041254. [PMID: 32070012 PMCID: PMC7072993 DOI: 10.3390/ijms21041254] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022] Open
Abstract
Meiotic maturation of oocyte relies on pre-synthesised maternal mRNA, the translation of which is highly coordinated in space and time. Here, we provide a detailed polysome profiling protocol that demonstrates a combination of the sucrose gradient ultracentrifugation in small SW55Ti tubes with the qRT-PCR-based quantification of 18S and 28S rRNAs in fractionated polysome profile. This newly optimised method, named Scarce Sample Polysome Profiling (SSP-profiling), is suitable for both scarce and conventional sample sizes and is compatible with downstream RNA-seq to identify polysome associated transcripts. Utilising SSP-profiling we have assayed the translatome of mouse oocytes at the onset of nuclear envelope breakdown (NEBD)—a developmental point, the study of which is important for furthering our understanding of the molecular mechanisms leading to oocyte aneuploidy. Our analyses identified 1847 transcripts with moderate to strong polysome occupancy, including abundantly represented mRNAs encoding mitochondrial and ribosomal proteins, proteasomal components, glycolytic and amino acids synthetic enzymes, proteins involved in cytoskeleton organization plus RNA-binding and translation initiation factors. In addition to transcripts encoding known players of meiotic progression, we also identified several mRNAs encoding proteins of unknown function. Polysome profiles generated using SSP-profiling were more than comparable to those developed using existing conventional approaches, being demonstrably superior in their resolution, reproducibility, versatility, speed of derivation and downstream protocol applicability.
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16
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Screening Readthrough Compounds to Suppress Nonsense Mutations: Possible Application to β-Thalassemia. J Clin Med 2020; 9:jcm9020289. [PMID: 31972957 PMCID: PMC7073686 DOI: 10.3390/jcm9020289] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 02/07/2023] Open
Abstract
Several types of thalassemia (including β039-thalassemia) are caused by nonsense mutations in genes controlling globin production, leading to premature translation termination and mRNA destabilization mediated by the nonsense mediated mRNA decay. Drugs (for instance, aminoglycosides) can be designed to suppress premature translation termination by inducing readthrough (or nonsense suppression) at the premature termination codon. These findings have introduced new hopes for the development of a pharmacologic approach to cure this genetic disease. In the present review, we first summarize the principle and current status of the chemical relief for the expression of functional proteins from genes otherwise unfruitful for the presence of nonsense mutations. Second, we compare data available on readthrough molecules for β0-thalassemia. The examples reported in the review strongly suggest that ribosomal readthrough should be considered as a therapeutic approach for the treatment of β0-thalassemia caused by nonsense mutations. Concluding, the discovery of molecules, exhibiting the property of inducing β-globin, such as readthrough compounds, is of great interest and represents a hope for several patients, whose survival will depend on the possible use of drugs rendering blood transfusion and chelation therapy unnecessary.
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17
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Bhadra M, Howell P, Dutta S, Heintz C, Mair WB. Alternative splicing in aging and longevity. Hum Genet 2019; 139:357-369. [PMID: 31834493 DOI: 10.1007/s00439-019-02094-6] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 11/24/2019] [Indexed: 12/13/2022]
Abstract
Alternative pre-mRNA splicing increases the complexity of the proteome that can be generated from the available genomic coding sequences. Dysregulation of the splicing process has been implicated in a vast repertoire of diseases. However, splicing has recently been linked to both the aging process itself and pro-longevity interventions. This review focuses on recent research towards defining RNA splicing as a new hallmark of aging. We highlight dysfunctional alternative splicing events that contribute to the aging phenotype across multiple species, along with recent efforts toward deciphering mechanistic roles for RNA splicing in the regulation of aging and longevity. Further, we discuss recent research demonstrating a direct requirement for specific splicing factors in pro-longevity interventions, and specifically how nutrient signaling pathways interface to splicing factor regulation and downstream splicing targets. Finally, we review the emerging potential of using splicing profiles as a predictor of biological age and life expectancy. Understanding the role of RNA splicing components and downstream targets altered in aging may provide opportunities to develop therapeutics and ultimately extend healthy lifespan in humans.
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Affiliation(s)
- Malini Bhadra
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Porsha Howell
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Sneha Dutta
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Caroline Heintz
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - William B Mair
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
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18
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Rollins JA, Shaffer D, Snow SS, Kapahi P, Rogers AN. Dietary restriction induces posttranscriptional regulation of longevity genes. Life Sci Alliance 2019; 2:2/4/e201800281. [PMID: 31253655 PMCID: PMC6600014 DOI: 10.26508/lsa.201800281] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 12/12/2022] Open
Abstract
Dietary restriction (DR) increases life span through adaptive changes in gene expression. To understand more about these changes, we analyzed the transcriptome and translatome of Caenorhabditis elegans subjected to DR. Transcription of muscle regulatory and structural genes increased, whereas increased expression of amino acid metabolism and neuropeptide signaling genes was controlled at the level of translation. Evaluation of posttranscriptional regulation identified putative roles for RNA-binding proteins, RNA editing, miRNA, alternative splicing, and nonsense-mediated decay in response to nutrient limitation. Using RNA interference, we discovered several differentially expressed genes that regulate life span. We also found a compensatory role for translational regulation, which offsets dampened expression of a large subset of transcriptionally down-regulated genes. Furthermore, 3' UTR editing and intron retention increase under DR and correlate with diminished translation, whereas trans-spliced genes are refractory to reduced translation efficiency compared with messages with the native 5' UTR. Finally, we find that smg-6 and smg-7, which are genes governing selection and turnover of nonsense-mediated decay targets, are required for increased life span under DR.
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Affiliation(s)
- Jarod A Rollins
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME, USA
| | - Dan Shaffer
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME, USA
| | - Santina S Snow
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME, USA
| | - Pankaj Kapahi
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Aric N Rogers
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME, USA
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19
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Usuki F, Yamashita A, Fujimura M. Environmental stresses suppress nonsense-mediated mRNA decay (NMD) and affect cells by stabilizing NMD-targeted gene expression. Sci Rep 2019; 9:1279. [PMID: 30718659 PMCID: PMC6362056 DOI: 10.1038/s41598-018-38015-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/05/2018] [Indexed: 12/31/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a cellular mechanism that eliminates mRNAs that harbor premature translation termination codons (PTCs). Here, we investigated the effects of environmental stresses (oxidative stress and endoplasmic reticulum (ER) stress) on NMD activity. Methylmercury (MeHg) was used to cause oxidative stress and thapsigargin to stress the ER. NMD suppression, evidenced by upregulation of NMD-sensitive mRNAs and a decrease in UPF1 phosphorylation, was observed in MeHg-treated myogenic cells, cerebral cortical neuronal cells, and astroglial cells. Mild ER stress amplified NMD suppression caused by MeHg. To elucidate the cause of stress-induced NMD suppression, the role of the phospho-eIF2α/ATF4 pathway was investigated. Knockdown and non-phosphorylatable eIF2α-transfection studies demonstrated the critical role of phospho-eIF2α-mediated repression of translation in mild ER stress-induced NMD suppression. However, NMD suppression was also observed in phospho-eIF2α-deficient cells under mild ER stress. Mechanistic target of rapamycin suppression-induced inhibition of cap-dependent translation, and downregulation of the NMD components UPF1, SMG7, and eIF4A3, were probably involved in stress-induced NMD suppression. Our results indicate that stress-induced NMD suppression has the potential to affect the condition of cells and phenotypes of PTC-related diseases under environmental stresses by stabilizing NMD-targeted gene expression.
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Affiliation(s)
- Fusako Usuki
- Department of Clinical Medicine, National Institute for Minamata Disease, 4058-18 Hama, Minamata, 867-0008, Japan.
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University School of Medicine, 3-9 Fuku-ura, Kanazawa, Yokohama, 236-0004, Japan
| | - Masatake Fujimura
- Basic Medical Sciences, National Institute for Minamata Disease, 4058-18 Hama, Minamata, 867-0008, Japan
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20
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Salvatori F, Pappadà M, Breveglieri G, D'Aversa E, Finotti A, Lampronti I, Gambari R, Borgatti M. UPF1 silenced cellular model systems for screening of read-through agents active on β 039 thalassemia point mutation. BMC Biotechnol 2018; 18:28. [PMID: 29764417 PMCID: PMC5952824 DOI: 10.1186/s12896-018-0435-0] [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: 09/12/2017] [Accepted: 04/16/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nonsense mutations promote premature translational termination, introducing stop codons within the coding region of mRNAs and causing inherited diseases, including thalassemia. For instance, in β039 thalassemia the CAG (glutamine) codon is mutated to the UAG stop codon, leading to premature translation termination and to mRNA destabilization through the well described NMD (nonsense-mediated mRNA decay). In order to develop an approach facilitating translation and, therefore, protection from NMD, ribosomal read-through molecules, such as aminoglycoside antibiotics, have been tested on mRNAs carrying premature stop codons. These findings have introduced new hopes for the development of a pharmacological approach to the β039 thalassemia therapy. While several strategies, designed to enhance translational read-through, have been reported to inhibit NMD efficiency concomitantly, experimental tools for systematic analysis of mammalian NMD inhibition by translational read-through are lacking. RESULTS We developed a human cellular model of the β039 thalassemia mutation with UPF-1 suppressed and showing a partial NMD suppression. CONCLUSIONS This novel cellular model could be used for the screening of molecules exhibiting preferential read-through activity allowing a great rescue of the mutated transcripts.
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Affiliation(s)
- Francesca Salvatori
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy
| | - Mariangela Pappadà
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy
| | - Giulia Breveglieri
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy.,Biotechnology Center, University of Ferrara, Ferrara, Italy
| | - Elisabetta D'Aversa
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy
| | - Alessia Finotti
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy
| | - Ilaria Lampronti
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy
| | - Roberto Gambari
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy. .,Biotechnology Center, University of Ferrara, Ferrara, Italy.
| | - Monica Borgatti
- Department of Life Sciences and Biotechnology, Biochemistry and Molecular Biology Section, University of Ferrara, Via Fossato di Mortara 74, 44121, Ferrara, Italy.
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21
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Abstract
In mammals, cap-dependent translation of mRNAs is initiated by two distinct mechanisms: cap-binding complex (CBC; a heterodimer of CBP80 and 20)-dependent translation (CT) and eIF4E-dependent translation (ET). Both translation initiation mechanisms share common features in driving cap-dependent translation; nevertheless, they can be distinguished from each other based on their molecular features and biological roles. CT is largely associated with mRNA surveillance such as nonsense-mediated mRNA decay (NMD), whereas ET is predominantly involved in the bulk of protein synthesis. However, several recent studies have demonstrated that CT and ET have similar roles in protein synthesis and mRNA surveillance. In a subset of mRNAs, CT preferentially drives the cap-dependent translation, as ET does, and ET is responsible for mRNA surveillance, as CT does. In this review, we summarize and compare the molecular features of CT and ET with a focus on the emerging roles of CT in translation.
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Affiliation(s)
- Incheol Ryu
- Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul 02841,
Korea
- School of Life Sciences, Korea University, Seoul 02841,
Korea
| | - Yoon Ki Kim
- Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul 02841,
Korea
- School of Life Sciences, Korea University, Seoul 02841,
Korea
- Corresponding author. Tel: +82-2-3290-3410; Fax: +82-2-923-9923; E-mail:
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