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van der Werf I, Sneifer J, Jamieson C. RNA Modifications Shape Hematopoietic Stem Cell Aging: Beyond the Code. FEBS Lett 2024. [PMID: 39252150 DOI: 10.1002/1873-3468.15014] [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: 01/18/2024] [Revised: 02/21/2024] [Accepted: 03/07/2024] [Indexed: 09/11/2024]
Abstract
Hematopoietic system aging is characterized by both hematopoietic stem cell (HSC) and niche degeneration resulting in myeloid lineage-biased differentiation, reduced B cell and T cell lymphopoiesis, increased HSC mobilization, and fat deposition in the bone marrow. Both alterations in RNA splicing and editing during HSC aging contribute to increased myeloid lineage skewing and inflammation-responsive transcription factors, underscoring the importance of epitranscriptomic mechanisms in the acquisition of an age-related phenotype.
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Affiliation(s)
- Inge van der Werf
- Sanford Stem Cell Institute, Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California, San Diego, La Jolla, California, 92037, USA
| | - Jenna Sneifer
- Sanford Stem Cell Institute, Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California, San Diego, La Jolla, California, 92037, USA
| | - Catriona Jamieson
- Sanford Stem Cell Institute, Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California, San Diego, La Jolla, California, 92037, USA
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2
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Sturchio A, Rocha EM, Kauffman MA, Marsili L, Mahajan A, Saraf AA, Vizcarra JA, Guo Z, Espay AJ. Recalibrating the Why and Whom of Animal Models in Parkinson Disease: A Clinician's Perspective. Brain Sci 2024; 14:151. [PMID: 38391726 PMCID: PMC10887152 DOI: 10.3390/brainsci14020151] [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: 12/04/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 02/24/2024] Open
Abstract
Animal models have been used to gain pathophysiologic insights into Parkinson's disease (PD) and aid in the translational efforts of interventions with therapeutic potential in human clinical trials. However, no disease-modifying therapy for PD has successfully emerged from model predictions. These translational disappointments warrant a reappraisal of the types of preclinical questions asked of animal models. Besides the limitations of experimental designs, the one-size convergence and oversimplification yielded by a model cannot recapitulate the molecular diversity within and between PD patients. Here, we compare the strengths and pitfalls of different models, review the discrepancies between animal and human data on similar pathologic and molecular mechanisms, assess the potential of organoids as novel modeling tools, and evaluate the types of questions for which models can guide and misguide. We propose that animal models may be of greatest utility in the evaluation of molecular mechanisms, neural pathways, drug toxicity, and safety but can be unreliable or misleading when used to generate pathophysiologic hypotheses or predict therapeutic efficacy for compounds with potential neuroprotective effects in humans. To enhance the translational disease-modification potential, the modeling must reflect the biology not of a diseased population but of subtypes of diseased humans to distinguish What data are relevant and to Whom.
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Affiliation(s)
- Andrea Sturchio
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Emily M Rocha
- Pittsburgh Institute for Neurodegenerative Diseases, Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Marcelo A Kauffman
- Consultorio y Laboratorio de Neurogenética, Centro Universitario de Neurología José María Ramos Mejía, Buenos Aires C1221ADC, Argentina
| | - Luca Marsili
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Abhimanyu Mahajan
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Ameya A Saraf
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Joaquin A Vizcarra
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 15213, USA
| | - Ziyuan Guo
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Cincinnati Children's Hospital, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Alberto J Espay
- James J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
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3
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Santos LGC, Parreira VDSC, da Silva EMG, Santos MDM, Fernandes ADF, Neves-Ferreira AGDC, Carvalho PC, Freitas FCDP, Passetti F. SpliceProt 2.0: A Sequence Repository of Human, Mouse, and Rat Proteoforms. Int J Mol Sci 2024; 25:1183. [PMID: 38256255 PMCID: PMC10816255 DOI: 10.3390/ijms25021183] [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: 10/31/2023] [Revised: 12/15/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
SpliceProt 2.0 is a public proteogenomics database that aims to list the sequence of known proteins and potential new proteoforms in human, mouse, and rat proteomes. This updated repository provides an even broader range of computationally translated proteins and serves, for example, to aid with proteomic validation of splice variants absent from the reference UniProtKB/SwissProt database. We demonstrate the value of SpliceProt 2.0 to predict orthologous proteins between humans and murines based on transcript reconstruction, sequence annotation and detection at the transcriptome and proteome levels. In this release, the annotation data used in the reconstruction of transcripts based on the methodology of ternary matrices were acquired from new databases such as Ensembl, UniProt, and APPRIS. Another innovation implemented in the pipeline is the exclusion of transcripts predicted to be susceptible to degradation through the NMD pathway. Taken together, our repository and its applications represent a valuable resource for the proteogenomics community.
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Affiliation(s)
- Letícia Graziela Costa Santos
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
| | - Vinícius da Silva Coutinho Parreira
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
| | - Esdras Matheus Gomes da Silva
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
- Laboratory of Toxinology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (FIOCRUZ), Av. Brazil 4036, Campus Maré, Rio de Janeiro 21040-361, RJ, Brazil
| | - Marlon Dias Mariano Santos
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
| | - Alexander da Franca Fernandes
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
| | - Ana Gisele da Costa Neves-Ferreira
- Laboratory of Toxinology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (FIOCRUZ), Av. Brazil 4036, Campus Maré, Rio de Janeiro 21040-361, RJ, Brazil
| | - Paulo Costa Carvalho
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
| | - Flávia Cristina de Paula Freitas
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
- Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luis, Km 235, São Carlos 13565-905, SP, Brazil
| | - Fabio Passetti
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rua Professor Algacyr Munhoz Mader 3775, Cidade Industrial De Curitiba, Curitiba 81310-020, PR, Brazil
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4
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Khalifah BA, Alghamdi SA, Alhasan AH. Unleashing the potential of catalytic RNAs to combat mis-spliced transcripts. Front Bioeng Biotechnol 2023; 11:1244377. [PMID: 38047291 PMCID: PMC10690607 DOI: 10.3389/fbioe.2023.1244377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/23/2023] [Indexed: 12/05/2023] Open
Abstract
Human transcriptome can undergo RNA mis-splicing due to spliceopathies contributing to the increasing number of genetic diseases including muscular dystrophy (MD), Alzheimer disease (AD), Huntington disease (HD), myelodysplastic syndromes (MDS). Intron retention (IR) is a major inducer of spliceopathies where two or more introns remain in the final mature mRNA and account for many intronic expansion diseases. Potential removal of such introns for therapeutic purposes can be feasible when utilizing bioinformatics, catalytic RNAs, and nano-drug delivery systems. Overcoming delivery challenges of catalytic RNAs was discussed in this review as a future perspective highlighting the significance of utilizing synthetic biology in addition to high throughput deep sequencing and computational approaches for the treatment of mis-spliced transcripts.
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Affiliation(s)
- Bashayer A. Khalifah
- Institute for Bioengineering, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
- Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Ali H. Alhasan
- Institute for Bioengineering, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
- College of Science and General Studies, Alfaisal University, Riyadh, Saudi Arabia
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5
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Yang YT, Yao CY, Chiu PJ, Kao CJ, Hou HA, Lin CC, Chou WC, Tien HF. Evaluation of the clinical significance of global mRNA alternative splicing in patients with acute myeloid leukemia. Am J Hematol 2023; 98:784-793. [PMID: 36855936 DOI: 10.1002/ajh.26893] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 03/02/2023]
Abstract
Aberrant alternative splicing (AS) is involved in leukemogenesis. This study explored the clinical impact of alterations in global AS patterns in 341 patients with acute myeloid leukemia (AML) newly diagnosed at the National Taiwan University Hospital and validated it using The Cancer Genome Atlas (TCGA) cohort. While studying normal cord blood CD34+ /CD38- cells, we found that AML cells exhibited significantly different global splicing patterns. AML with mutated TP53 had a particularly high degree of genome-wide aberrations in the splicing patterns. Aberrance in the global splicing pattern was an independent unfavorable prognostic factor affecting the overall survival of patients with AML receiving standard intensive chemotherapy. The integration of global splicing patterns into the 2022 European LeukemiaNet risk classification could stratify AML patients into four groups with distinct prognoses in both our experimental and TCGA cohorts. We further identified four genes with AS alterations that harbored prognostic significance in both of these cohorts. Moreover, these survival-associated AS events are involved in several important cellular processes that might be associated with poor response to intensive chemotherapy. In summary, our study demonstrated the clinical and biological implications of differential global splicing patterns in AML patients. Further studies with larger prospective cohorts are required to confirm these findings.
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Affiliation(s)
- Yi-Tsung Yang
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chi-Yuan Yao
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Po-Ju Chiu
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Hematological Oncology, National Taiwan University Cancer Center, Taipei, Taiwan
| | - Chein-Jun Kao
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsin-An Hou
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chien-Chin Lin
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Wen-Chien Chou
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hwei-Fang Tien
- Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Department of Internal Medicine, Far-Eastern Memorial Hospital, New Taipei City, Taiwan
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6
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Kameda-Smith MM, Zhu H, Luo EC, Suk Y, Xella A, Yee B, Chokshi C, Xing S, Tan F, Fox RG, Adile AA, Bakhshinyan D, Brown K, Gwynne WD, Subapanditha M, Miletic P, Picard D, Burns I, Moffat J, Paruch K, Fleming A, Hope K, Provias JP, Remke M, Lu Y, Reya T, Venugopal C, Reimand J, Wechsler-Reya RJ, Yeo GW, Singh SK. Characterization of an RNA binding protein interactome reveals a context-specific post-transcriptional landscape of MYC-amplified medulloblastoma. Nat Commun 2022; 13:7506. [PMID: 36473869 PMCID: PMC9726987 DOI: 10.1038/s41467-022-35118-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 11/18/2022] [Indexed: 12/12/2022] Open
Abstract
Pediatric medulloblastoma (MB) is the most common solid malignant brain neoplasm, with Group 3 (G3) MB representing the most aggressive subgroup. MYC amplification is an independent poor prognostic factor in G3 MB, however, therapeutic targeting of the MYC pathway remains limited and alternative therapies for G3 MB are urgently needed. Here we show that the RNA-binding protein, Musashi-1 (MSI1) is an essential mediator of G3 MB in both MYC-overexpressing mouse models and patient-derived xenografts. MSI1 inhibition abrogates tumor initiation and significantly prolongs survival in both models. We identify binding targets of MSI1 in normal neural and G3 MB stem cells and then cross referenced these data with unbiased large-scale screens at the transcriptomic, translatomic and proteomic levels to systematically dissect its functional role. Comparative integrative multi-omic analyses of these large datasets reveal cancer-selective MSI1-bound targets sharing multiple MYC associated pathways, providing a valuable resource for context-specific therapeutic targeting of G3 MB.
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Affiliation(s)
- Michelle M. Kameda-Smith
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON Canada
| | - Helen Zhu
- grid.419890.d0000 0004 0626 690XComputational Biology Program, Ontario Institute for Cancer Research, Toronto, Canada ,grid.17063.330000 0001 2157 2938Department of Medical Biophysics, University of Toronto, Toronto, Canada ,grid.231844.80000 0004 0474 0428University Health Network, Toronto, ON Canada ,grid.494618.6Vector Institute Toronto, Toronto, ON Canada
| | - En-Ching Luo
- grid.266100.30000 0001 2107 4242Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA USA ,grid.266100.30000 0001 2107 4242Stem Cell Program, University of California San Diego, La Jolla, CA USA ,grid.468218.10000 0004 5913 3393Sanford Consortium for Regenerative Medicine, La Jolla, CA USA
| | - Yujin Suk
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Michael G DeGroote School of Medicine, McMaster University, Hamilton, Canada
| | - Agata Xella
- grid.479509.60000 0001 0163 8573Tumor Initiation and Maintenance Program, National Cancer Institute-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA USA
| | - Brian Yee
- grid.266100.30000 0001 2107 4242Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA USA ,grid.266100.30000 0001 2107 4242Stem Cell Program, University of California San Diego, La Jolla, CA USA ,grid.468218.10000 0004 5913 3393Sanford Consortium for Regenerative Medicine, La Jolla, CA USA
| | - Chirayu Chokshi
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Sansi Xing
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Frederick Tan
- grid.266100.30000 0001 2107 4242Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA USA ,grid.266100.30000 0001 2107 4242Stem Cell Program, University of California San Diego, La Jolla, CA USA ,grid.468218.10000 0004 5913 3393Sanford Consortium for Regenerative Medicine, La Jolla, CA USA
| | - Raymond G. Fox
- grid.266100.30000 0001 2107 4242Departments of Pharmacology and Medicine, University of California San Diego School of Medicine, Sanford Consortium for Regenerative Medicine, La Jolla, CA USA
| | - Ashley A. Adile
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - David Bakhshinyan
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Kevin Brown
- grid.17063.330000 0001 2157 2938Donnelly Centre, Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - William D. Gwynne
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Minomi Subapanditha
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada
| | - Petar Miletic
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Daniel Picard
- grid.14778.3d0000 0000 8922 7789Department of Pediatric Oncology, Hematology, and Clinical Immunology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Ian Burns
- grid.25073.330000 0004 1936 8227Michael G DeGroote School of Medicine, McMaster University, Hamilton, Canada
| | - Jason Moffat
- grid.17063.330000 0001 2157 2938Donnelly Centre, Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Kamil Paruch
- grid.10267.320000 0001 2194 0956Department of Chemistry, CZ Openscreen, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic ,grid.483343.bInternational Clinical Research Center, St. Anne’s University Hospital in Brno, 602 00 Brno, Czech Republic
| | - Adam Fleming
- grid.25073.330000 0004 1936 8227McMaster University, Departments of Pediatrics, Hematology and Oncology Division, Hamilton, Canada
| | - Kristin Hope
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - John P. Provias
- grid.25073.330000 0004 1936 8227McMaster University, Departments of Neuropathology, Hamilton, Canada
| | - Marc Remke
- grid.14778.3d0000 0000 8922 7789Department of Pediatric Oncology, Hematology, and Clinical Immunology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Yu Lu
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada
| | - Tannishtha Reya
- grid.266100.30000 0001 2107 4242Departments of Pharmacology and Medicine, University of California San Diego School of Medicine, Sanford Consortium for Regenerative Medicine, La Jolla, CA USA ,grid.239585.00000 0001 2285 2675Present Address: Herbert Irving Comprehensive Cancer Center, Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY USA
| | - Chitra Venugopal
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON Canada
| | - Jüri Reimand
- grid.419890.d0000 0004 0626 690XComputational Biology Program, Ontario Institute for Cancer Research, Toronto, Canada ,grid.17063.330000 0001 2157 2938Department of Medical Biophysics, University of Toronto, Toronto, Canada ,grid.17063.330000 0001 2157 2938Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Robert J. Wechsler-Reya
- grid.479509.60000 0001 0163 8573Tumor Initiation and Maintenance Program, National Cancer Institute-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA USA ,grid.239585.00000 0001 2285 2675Present Address: Herbert Irving Comprehensive Cancer Center, Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY USA
| | - Gene W. Yeo
- grid.266100.30000 0001 2107 4242Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA USA ,grid.266100.30000 0001 2107 4242Stem Cell Program, University of California San Diego, La Jolla, CA USA ,grid.468218.10000 0004 5913 3393Sanford Consortium for Regenerative Medicine, La Jolla, CA USA
| | - Sheila K. Singh
- grid.25073.330000 0004 1936 8227Centre for Discovery in Cancer Research (CDCR), McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON Canada ,grid.25073.330000 0004 1936 8227McMaster University, Department of Pediatrics, Hamilton, Canada
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7
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Putscher E, Hecker M, Fitzner B, Boxberger N, Schwartz M, Koczan D, Lorenz P, Zettl UK. Genetic risk variants for multiple sclerosis are linked to differences in alternative pre-mRNA splicing. Front Immunol 2022; 13:931831. [PMID: 36405756 PMCID: PMC9670805 DOI: 10.3389/fimmu.2022.931831] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/12/2022] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system to which a genetic predisposition contributes. Over 200 genetic regions have been associated with increased disease risk, but the disease-causing variants and their functional impact at the molecular level are mostly poorly defined. We hypothesized that single-nucleotide polymorphisms (SNPs) have an impact on pre-mRNA splicing in MS. METHODS Our study focused on 10 bioinformatically prioritized SNP-gene pairs, in which the SNP has a high potential to alter alternative splicing events (ASEs). We tested for differential gene expression and differential alternative splicing in B cells from MS patients and healthy controls. We further examined the impact of the SNP genotypes on ASEs and on splice isoform expression levels. Novel genotype-dependent effects on splicing were verified with splicing reporter minigene assays. RESULTS We were able to confirm previously described findings regarding the relation of MS-associated SNPs with the ASEs of the pre-mRNAs from GSDMB and SP140. We also observed an increased IL7R exon 6 skipping when comparing relapsing and progressive MS patients to healthy subjects. Moreover, we found evidence that the MS risk alleles of the SNPs rs3851808 (EFCAB13), rs1131123 (HLA-C), rs10783847 (TSFM), and rs2014886 (TSFM) may contribute to a differential splicing pattern. Of particular interest is the genotype-dependent exon skipping of TSFM due to the SNP rs2014886. The minor allele T creates a donor splice site, resulting in the expression of the exon 3 and 4 of a short TSFM transcript isoform, whereas in the presence of the MS risk allele C, this donor site is absent, and thus the short transcript isoform is not expressed. CONCLUSION In summary, we found that genetic variants from MS risk loci affect pre-mRNA splicing. Our findings substantiate the role of ASEs with respect to the genetics of MS. Further studies on how disease-causing genetic variants may modify the interactions between splicing regulatory sequence elements and RNA-binding proteins can help to deepen our understanding of the genetic susceptibility to MS.
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Affiliation(s)
- Elena Putscher
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Michael Hecker
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Brit Fitzner
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Nina Boxberger
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Margit Schwartz
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Dirk Koczan
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Peter Lorenz
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Uwe Klaus Zettl
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
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8
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Casteels T, Bajew S, Reiniš J, Enders L, Schuster M, Fontaine F, Müller AC, Wagner BK, Bock C, Kubicek S. SMNDC1 links chromatin remodeling and splicing to regulate pancreatic hormone expression. Cell Rep 2022; 40:111288. [PMID: 36044849 DOI: 10.1016/j.celrep.2022.111288] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 04/06/2022] [Accepted: 08/09/2022] [Indexed: 11/28/2022] Open
Abstract
Insulin expression is primarily restricted to the pancreatic β cells, which are physically or functionally depleted in diabetes. Identifying targetable pathways repressing insulin in non-β cells, particularly in the developmentally related glucagon-secreting α cells, is an important aim of regenerative medicine. Here, we perform an RNA interference screen in a murine α cell line to identify silencers of insulin expression. We discover that knockdown of the splicing factor Smndc1 triggers a global repression of α cell gene-expression programs in favor of increased β cell markers. Mechanistically, Smndc1 knockdown upregulates the β cell transcription factor Pdx1 by modulating the activities of the BAF and Atrx chromatin remodeling complexes. SMNDC1's repressive role is conserved in human pancreatic islets, its loss triggering enhanced insulin secretion and PDX1 expression. Our study identifies Smndc1 as a key factor connecting splicing and chromatin remodeling to the control of insulin expression in human and mouse islet cells.
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Affiliation(s)
- Tamara Casteels
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Simon Bajew
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Carrer del Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Carrer del Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Jiří Reiniš
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Lennart Enders
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Michael Schuster
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Frédéric Fontaine
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - André C Müller
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | | | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria; Medical University of Vienna, Center for Medical Statistics, Informatics, and Intelligent Systems, Institute of Artificial Intelligence, 1090 Vienna, Austria
| | - Stefan Kubicek
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria.
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9
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Zhou D, Tran Y, Abou Elela S, Scott MS. SAPFIR: A webserver for the identification of alternative protein features. BMC Bioinformatics 2022; 23:250. [PMID: 35751026 PMCID: PMC9229502 DOI: 10.1186/s12859-022-04804-w] [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: 03/10/2022] [Accepted: 06/20/2022] [Indexed: 11/29/2022] Open
Abstract
Background Alternative splicing can increase the diversity of gene functions by generating multiple isoforms with different sequences and functions. However, the extent to which splicing events have functional consequences remains unclear and predicting the impact of splicing events on protein activity is limited to gene-specific analysis. Results To accelerate the identification of functionally relevant alternative splicing events we created SAPFIR, a predictor of protein features associated with alternative splicing events. This webserver tool uses InterProScan to predict protein features such as functional domains, motifs and sites in the human and mouse genomes and link them to alternative splicing events. Alternative protein features are displayed as functions of the transcripts and splice sites. SAPFIR could be used to analyze proteins generated from a single gene or a group of genes and can directly identify alternative protein features in large sequence data sets. The accuracy and utility of SAPFIR was validated by its ability to rediscover previously validated alternative protein domains. In addition, our de novo analysis of public datasets using SAPFIR indicated that only a small portion of alternative protein domains was conserved between human and mouse, and that in human, genes involved in nervous system process, regulation of DNA-templated transcription and aging are more likely to produce isoforms missing functional domains due to alternative splicing. Conclusion Overall SAPFIR represents a new tool for the rapid identification of functional alternative splicing events and enables the identification of cellular functions affected by a defined splicing program. SAPFIR is freely available at https://bioinfo-scottgroup.med.usherbrooke.ca/sapfir/, a website implemented in Python, with all major browsers supported. The source code is available at https://github.com/DelongZHOU/SAPFIR. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-022-04804-w.
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Affiliation(s)
- Delong Zhou
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Yvan Tran
- Département de Biochimie et Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Sherif Abou Elela
- Département de Microbiologie et d'infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
| | - Michelle S Scott
- Département de Biochimie et Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
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10
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Heidari A, Yazdanpanah N, Rezaei N. The role of Toll-like receptors and neuroinflammation in Parkinson's disease. J Neuroinflammation 2022; 19:135. [PMID: 35668422 PMCID: PMC9172200 DOI: 10.1186/s12974-022-02496-w] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 05/26/2022] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder, characterized by motor and non-motor symptoms, significantly affecting patients' life. Pathologically, PD is associated with the extensive degeneration of dopaminergic neurons in various regions of the central nervous system (CNS), specifically the substantia nigra. This neuronal loss is accompanied by the aggregation of misfolded protein, named α-synuclein. MAIN TEXT Recent studies detected several clues of neuroinflammation in PD samples using postmortem human PD brains and various PD animal models. Some evidence of neuroinflammation in PD patients included higher levels of proinflammatory cytokines in serum and cerebrospinal fluid (CSF), presence of activated microglia in various brain regions such as substantia nigra, infiltration of peripheral inflammatory cells in affected brain regions, and altered function of cellular immunity like monocytes phagocytosis defects. On the other side, Toll-like receptors (TLRs) are innate immune receptors primarily located on microglia, as well as other immune and non-immune cells, expressing pivotal roles in recognizing exogenous and endogenous stimuli and triggering inflammatory responses. Most studies indicated an increased expression of TLRs in the brain and peripheral blood cells of PD samples. Besides, this upregulation was associated with excessive neuroinflammation followed by neurodegeneration in affected regions. Therefore, evidence proposed that TLR-mediated neuroinflammation might lead to a dopaminergic neural loss in PD patients. In this regard, TLR2, TLR4, and TLR9 have the most prominent roles. CONCLUSION Although the presence of inflammation in acute phases of PD might have protective effects concerning the clearance of α-synuclein and delaying the disease advancement, the chronic activation of TLRs and neuroinflammation might lead to neurodegeneration, resulting in the disease progression. Therefore, this study aimed to review additional evidence of the contribution of TLRs and neuroinflammation to PD pathogenesis, with the hope that TLRs could serve as novel disease-modifying therapeutic targets in PD patients in the future.
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Affiliation(s)
- Arash Heidari
- Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Research Center for Immunodeficiencies, Children's Medical Center Hospital, Tehran University of Medical Sciences, Dr. Qarib St, Keshavarz Blvd, Tehran, 14194, Iran.,Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Niloufar Yazdanpanah
- Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Research Center for Immunodeficiencies, Children's Medical Center Hospital, Tehran University of Medical Sciences, Dr. Qarib St, Keshavarz Blvd, Tehran, 14194, Iran.,Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Nima Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center Hospital, Tehran University of Medical Sciences, Dr. Qarib St, Keshavarz Blvd, Tehran, 14194, Iran. .,Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran. .,Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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11
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Kwiatkowski M, Hotze M, Schumacher J, Asif AR, Pittol JMR, Brenig B, Ramljak S, Zischler H, Herlyn H. Protein speciation is likely to increase the chance of proteins to be determined in 2‐DE/MS. Electrophoresis 2022; 43:1203-1214. [DOI: 10.1002/elps.202000393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 11/30/2021] [Accepted: 02/02/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Marcel Kwiatkowski
- Department of Biochemistry and Center for Molecular Biosciences Innsbruck University of Innsbruck Innsbruck Austria
| | - Madlen Hotze
- Department of Biochemistry and Center for Molecular Biosciences Innsbruck University of Innsbruck Innsbruck Austria
| | | | - Abdul R. Asif
- Department of Clinical Chemistry/UMG‐Laboratories University Medical Center Göttingen Germany
| | - Jose Miguel Ramos Pittol
- Department of Biochemistry and Center for Molecular Biosciences Innsbruck University of Innsbruck Innsbruck Austria
| | - Bertram Brenig
- Department of Molecular Biology of Livestock Institute of Veterinary Medicine University of Göttingen Göttingen Germany
| | | | - Hans Zischler
- Institute of Organismic and Molecular Evolution, Anthropology University of Mainz Mainz Germany
| | - Holger Herlyn
- Institute of Organismic and Molecular Evolution, Anthropology University of Mainz Mainz Germany
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12
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Boudreault S, Durand M, Martineau CA, Perreault JP, Lemay G, Bisaillon M. Reovirus μ2 protein modulates host cell alternative splicing by reducing protein levels of U5 snRNP core components. Nucleic Acids Res 2022; 50:5263-5281. [PMID: 35489070 PMCID: PMC9122528 DOI: 10.1093/nar/gkac272] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/25/2022] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
Mammalian orthoreovirus (MRV) is a double-stranded RNA virus from the Reoviridae family presenting a promising activity as an oncolytic virus. Recent studies have underlined MRV’s ability to alter cellular alternative splicing (AS) during infection, with a limited understanding of the mechanisms at play. In this study, we investigated how MRV modulates AS. Using a combination of cell biology and reverse genetics experiments, we demonstrated that the M1 gene segment, encoding the μ2 protein, is the primary determinant of MRV’s ability to alter AS, and that the amino acid at position 208 in μ2 is critical to induce these changes. Moreover, we showed that the expression of μ2 by itself is sufficient to trigger AS changes, and its ability to enter the nucleus is not required for all these changes. Moreover, we identified core components of the U5 snRNP (i.e. EFTUD2, PRPF8, and SNRNP200) as interactors of μ2 that are required for MRV modulation of AS. Finally, these U5 snRNP components are reduced at the protein level by both MRV infection and μ2 expression. Our findings identify the reduction of U5 snRNP components levels as a new mechanism by which viruses alter cellular AS.
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Affiliation(s)
- Simon Boudreault
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec J1E 4K8, Canada
| | - Mathieu Durand
- Plateforme de RNomique, Université de Sherbrooke, Sherbrooke, Québec J1E 4K8, Canada
| | - Carole-Anne Martineau
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec J1E 4K8, Canada
| | - Jean-Pierre Perreault
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec J1E 4K8, Canada
| | - Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Faculté de médecine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Martin Bisaillon
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec J1E 4K8, Canada
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13
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Gallo CM, Labadorf AT, Ho A, Beffert U. Single molecule, long-read Apoer2 sequencing identifies conserved and species-specific splicing patterns. Genomics 2022; 114:110318. [PMID: 35192893 PMCID: PMC8978334 DOI: 10.1016/j.ygeno.2022.110318] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 11/04/2022]
Abstract
Apolipoprotein E receptor 2 (Apoer2) is a synaptic receptor in the brain that binds disease-relevant ligand Apolipoprotein E (Apoe) and is highly alternatively spliced. We examined alternative splicing (AS) of conserved Apoer2 exons across vertebrate species and identified gain of exons in mammals encoding functional domains such as the cytoplasmic and furin inserts, and loss of an exon in primates encoding the eighth LDLa repeat, likely altering receptor surface levels and ligand-binding specificity. We utilized single molecule, long-read RNA sequencing to profile full-length Apoer2 isoforms and identified 68 and 48 unique full-length Apoer2 transcripts in the mouse and human cerebral cortex, respectively. Furthermore, we identified two exons encoding protein functional domains, the third EGF-precursor like repeat and glycosylation domain, that are tandemly skipped specifically in mouse. Our study provides new insight into Apoer2 isoform complexity in the vertebrate brain and highlights species-specific differences in splicing decisions that support functional diversity.
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Affiliation(s)
- Christina M Gallo
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, United States of America; Department of Biology, Boston University, United States of America
| | - Adam T Labadorf
- Bioinformatics Program, Boston University, United States of America; Department of Neurology, Boston University School of Medicine, United States of America
| | - Angela Ho
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, United States of America; Department of Biology, Boston University, United States of America.
| | - Uwe Beffert
- Department of Biology, Boston University, United States of America
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14
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Patient-specific MDS-RS iPSCs define the mis-spliced transcript repertoire and chromatin landscape of SF3B1-mutant HSPCs. Blood Adv 2022; 6:2992-3005. [PMID: 35042235 PMCID: PMC9131920 DOI: 10.1182/bloodadvances.2021006325] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/17/2021] [Indexed: 11/20/2022] Open
Abstract
Genetically matched MDS-RS and normal patient-specific iPSC-HSPCs are used to derive a mutant SF3B1 splicing signature. Integrated transcriptomics and chromatin accessibility nominate TEAD as a putative novel transcriptional regulator of SF3B1K700E cells.
SF3B1K700E is the most frequent mutation in myelodysplastic syndrome (MDS), but the mechanisms by which it drives MDS pathogenesis remain unclear. We derived a panel of 18 genetically matched SF3B1K700E- and SF3B1WT-induced pluripotent stem cell (iPSC) lines from patients with MDS with ring sideroblasts (MDS-RS) harboring isolated SF3B1K700E mutations and performed RNA and ATAC sequencing in purified CD34+/CD45+ hematopoietic stem/progenitor cells (HSPCs) derived from them. We developed a novel computational framework integrating splicing with transcript usage and gene expression analyses and derived a SF3B1K700E splicing signature consisting of 59 splicing events linked to 34 genes, which associates with the SF3B1 mutational status of primary MDS patient cells. The chromatin landscape of SF3B1K700E HSPCs showed increased priming toward the megakaryocyte- erythroid lineage. Transcription factor motifs enriched in chromatin regions more accessible in SF3B1K700E cells included, unexpectedly, motifs of the TEA domain (TEAD) transcription factor family. TEAD expression and transcriptional activity were upregulated in SF3B1-mutant iPSC-HSPCs, in support of a Hippo pathway-independent role of TEAD as a potential novel transcriptional regulator of SF3B1K700E cells. This study provides a comprehensive characterization of the transcriptional and chromatin landscape of SF3B1K700E HSPCs and nominates novel mis-spliced genes and transcriptional programs with putative roles in MDS-RS disease biology.
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15
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Baldini L, Robert A, Charpentier B, Labialle S. Phylogenetic and molecular analyses identify SNORD116 targets involved in the Prader Willi syndrome. Mol Biol Evol 2021; 39:6454102. [PMID: 34893870 PMCID: PMC8789076 DOI: 10.1093/molbev/msab348] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The eutherian-specific SNORD116 family of repeated box C/D snoRNA genes is suspected to play a major role in the Prader–Willi syndrome (PWS), yet its molecular function remains poorly understood. Here, we combined phylogenetic and molecular analyses to identify candidate RNA targets. Based on the analysis of several eutherian orthologs, we found evidence of extensive birth-and-death and conversion events during SNORD116 gene history. However, the consequences for phylogenetic conservation were heterogeneous along the gene sequence. The standard snoRNA elements necessary for RNA stability and association with dedicated core proteins were the most conserved, in agreement with the hypothesis that SNORD116 generate genuine snoRNAs. In addition, one of the two antisense elements typically involved in RNA target recognition was largely dominated by a unique sequence present in at least one subset of gene paralogs in most species, likely the result of a selective effect. In agreement with a functional role, this ASE exhibited a hybridization capacity with putative mRNA targets that was strongly conserved in eutherians. Moreover, transient downregulation experiments in human cells showed that Snord116 controls the expression and splicing levels of these mRNAs. The functions of two of them, diacylglycerol kinase kappa and Neuroligin 3, extend the description of the molecular bases of PWS and reveal unexpected molecular links with the Fragile X syndrome and autism spectrum disorders.
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Affiliation(s)
- Laeya Baldini
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
| | - Anne Robert
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
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16
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Wheeler EC, Vora S, Mayer D, Kotini AG, Olszewska M, Park SS, Guccione E, Teruya-Feldstein J, Silverman L, Sunahara RK, Yeo GW, Papapetrou EP. Integrative RNA-omics discovers GNAS alternative splicing as a phenotypic driver of splicing factor-mutant neoplasms. Cancer Discov 2021; 12:836-855. [PMID: 34620690 DOI: 10.1158/2159-8290.cd-21-0508] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/10/2021] [Accepted: 09/17/2021] [Indexed: 11/16/2022]
Abstract
Mutations in splicing factors (SFs) are the predominant class of mutations in myelodysplastic syndrome (MDS), but convergent downstream disease drivers remain elusive. To identify common direct targets of mis-splicing by mutant U2AF1 and SRSF2, we performed RNA-Seq and eCLIP in human hematopoietic stem/progenitor cells (HSPCs) derived from isogenic induced pluripotent stem cell (iPSC) models. Integrative analyses of alternative splicing and differential binding converged on a long isoform of GNAS (GNAS-L), promoted by both mutant factors. MDS population genetics, functional and biochemical analyses support that GNAS-L is a driver of MDS and encodes a hyperactive long form of the stimulatory G protein alpha subunit, Gas-L, that activates ERK/MAPK signaling. SF-mutant MDS cells have activated ERK signaling and consequently are sensitive to MEK inhibitors. Our findings highlight an unexpected and unifying mechanism by which SRSF2 and U2AF1 mutations drive oncogenesis with potential therapeutic implications for MDS and other SF-mutant neoplasms.
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Affiliation(s)
| | - Shailee Vora
- Oncological Sciences, Icahn School of Medicine at Mount Sinai
| | | | | | | | - Samuel S Park
- Cellular and Molecular Medicine, University of California, San Diego
| | | | | | | | | | - Gene W Yeo
- Cellular and Molecular Medicine, University of California, San Diego
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17
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Chandra S, Srinivasan S, Batra J. Hepatocyte nuclear factor 1 beta: A perspective in cancer. Cancer Med 2021; 10:1791-1804. [PMID: 33580750 PMCID: PMC7940219 DOI: 10.1002/cam4.3676] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 12/17/2022] Open
Abstract
Hepatocyte nuclear factor 1 beta (HNF1 β/B) exists as a homeobox transcription factor having a vital role in the embryonic development of organs mainly liver, kidney and pancreas. Initially described as a gene causing maturity‐onset diabetes of the young (MODY), HNF1β expression deregulation and single nucleotide polymorphisms in HNF1β have now been associated with several tumours including endometrial, prostate, ovarian, hepatocellular, renal and colorectal cancers. Its function has been studied either as homodimer or heterodimer with HNF1α. In this review, the role of HNF1B in different cancers will be discussed along with the role of its splice variants, and its emerging role as a potential biomarker in cancer.
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Affiliation(s)
- Shubhra Chandra
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
| | - Srilakshmi Srinivasan
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
| | - Jyotsna Batra
- Institute of Health and Biomedical Innovation and School of Biomedical Sciences, Australian Prostate Cancer Research Centre-Queensland, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
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18
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Koterniak B, Pilaka PP, Gracida X, Schneider LM, Pritišanac I, Zhang Y, Calarco JA. Global regulatory features of alternative splicing across tissues and within the nervous system of C. elegans. Genome Res 2020; 30:1766-1780. [PMID: 33127752 PMCID: PMC7706725 DOI: 10.1101/gr.267328.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/28/2020] [Indexed: 12/27/2022]
Abstract
Alternative splicing plays a major role in shaping tissue-specific transcriptomes. Among the broad tissue types present in metazoans, the central nervous system contains some of the highest levels of alternative splicing. Although many documented examples of splicing differences between broad tissue types exist, there remains much to be understood about the splicing factors and the cis sequence elements controlling tissue and neuron subtype-specific splicing patterns. By using translating ribosome affinity purification coupled with deep-sequencing (TRAP-seq) in Caenorhabditis elegans, we have obtained high coverage profiles of ribosome-associated mRNA for three broad tissue classes (nervous system, muscle, and intestine) and two neuronal subtypes (dopaminergic and serotonergic neurons). We have identified hundreds of splice junctions that exhibit distinct splicing patterns between tissue types or within the nervous system. Alternative splicing events differentially regulated between tissues are more often frame-preserving, are more highly conserved across Caenorhabditis species, and are enriched in specific cis regulatory motifs, when compared with other types of exons. By using this information, we have identified a likely mechanism of splicing repression by the RNA-binding protein UNC-75/CELF via interactions with cis elements that overlap a 5′ splice site. Alternatively spliced exons also overlap more frequently with intrinsically disordered peptide regions than constitutive exons. Moreover, regulated exons are often shorter than constitutive exons but are flanked by longer intron sequences. Among these tissue-regulated exons are several highly conserved microexons <27 nt in length. Collectively, our results indicate a rich layer of tissue-specific gene regulation at the level of alternative splicing in C. elegans that parallels the evolutionary forces and constraints observed across metazoa.
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Affiliation(s)
- Bina Koterniak
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Pallavi P Pilaka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Xicotencatl Gracida
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Lisa-Marie Schneider
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada.,Department of Chemistry, University of Bayreuth, 95447 Bayreuth, Germany
| | - Iva Pritišanac
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Yun Zhang
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - John A Calarco
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
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19
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Chua BA, Van Der Werf I, Jamieson C, Signer RAJ. Post-Transcriptional Regulation of Homeostatic, Stressed, and Malignant Stem Cells. Cell Stem Cell 2020; 26:138-159. [PMID: 32032524 PMCID: PMC7158223 DOI: 10.1016/j.stem.2020.01.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cellular identity is not driven by differences in genomic content but rather by epigenomic, transcriptomic, and proteomic heterogeneity. Although regulation of the epigenome plays a key role in shaping stem cell hierarchies, differential expression of transcripts only partially explains protein abundance. The epitranscriptome, translational control, and protein degradation have emerged as fundamental regulators of proteome complexity that regulate stem cell identity and function. Here, we discuss how post-transcriptional mechanisms enable stem cell homeostasis and responsiveness to developmental cues and environmental stressors by rapidly shaping the content of their proteome and how these processes are disrupted in pre-malignant and malignant states.
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Affiliation(s)
- Bernadette A Chua
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California San Diego, La Jolla, CA, 92093 USA
| | - Inge Van Der Werf
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California San Diego, La Jolla, CA, 92093 USA; Sanford Stem Cell Clinical Center, La Jolla, CA 92037, USA
| | - Catriona Jamieson
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California San Diego, La Jolla, CA, 92093 USA; Sanford Stem Cell Clinical Center, La Jolla, CA 92037, USA.
| | - Robert A J Signer
- Division of Regenerative Medicine, Department of Medicine, Moores Cancer Center, University of California San Diego, La Jolla, CA, 92093 USA.
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20
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Kuitche E, Jammali S, Ouangraoua A. SimSpliceEvol: alternative splicing-aware simulation of biological sequence evolution. BMC Bioinformatics 2019; 20:640. [PMID: 31842741 PMCID: PMC6916212 DOI: 10.1186/s12859-019-3207-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Background It is now well established that eukaryotic coding genes have the ability to produce more than one type of transcript thanks to the mechanisms of alternative splicing and alternative transcription. Because of the lack of gold standard real data on alternative splicing, simulated data constitute a good option for evaluating the accuracy and the efficiency of methods developed for splice-aware sequence analysis. However, existing sequence evolution simulation methods do not model alternative splicing, and so they can not be used to test spliced sequence analysis methods. Results We propose a new method called SimSpliceEvol for simulating the evolution of sets of alternative transcripts along the branches of an input gene tree. In addition to traditional sequence evolution events, the simulation also includes gene exon-intron structure evolution events and alternative splicing events that modify the sets of transcripts produced from genes. SimSpliceEvol was implemented in Python. The source code is freely available at https://github.com/UdeS-CoBIUS/SimSpliceEvol. Conclusions Data generated using SimSpliceEvol are useful for testing spliced RNA sequence analysis methods such as methods for spliced alignment of cDNA and genomic sequences, multiple cDNA alignment, orthologous exons identification, splicing orthology inference, transcript phylogeny inference, which requires to know the real evolutionary relationships between the sequences.
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Affiliation(s)
- Esaie Kuitche
- Department of Computer Science, University of Sherbrooke, 2500 Boulevard de l'Université, Quebec, J1K2R1, Canada.
| | - Safa Jammali
- Department of Computer Science, University of Sherbrooke, 2500 Boulevard de l'Université, Quebec, J1K2R1, Canada.,Department of Biochemistry, University of Sherbrooke, 3001 12e avenue Nord, Quebec, J1H5N4, Canada
| | - Aïda Ouangraoua
- Department of Computer Science, University of Sherbrooke, 2500 Boulevard de l'Université, Quebec, J1K2R1, Canada
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21
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Animal Models for Parkinson's Disease Research: Trends in the 2000s. Int J Mol Sci 2019; 20:ijms20215402. [PMID: 31671557 PMCID: PMC6862023 DOI: 10.3390/ijms20215402] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 12/21/2022] Open
Abstract
Parkinson’s disease (PD) is a chronic and progressive movement disorder and the second most common neurodegenerative disease. Although many studies have been conducted, there is an unmet clinical need to develop new treatments because, currently, only symptomatic therapies are available. To achieve this goal, clarification of the pathology is required. Attempts have been made to emulate human PD and various animal models have been developed over the decades. Neurotoxin models have been commonly used for PD research. Recently, advances in transgenic technology have enabled the development of genetic models that help to identify new approaches in PD research. However, PD animal model trends have not been investigated. Revealing the trends for PD research will be valuable for increasing our understanding of the positive and negative aspects of each model. In this article, we clarified the trends for animal models that were used to research PD in the 2000s, and we discussed each model based on these trends.
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22
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Shimomura H, Lee T, Tanaka Y, Awano H, Itoh K, Nishino I, Takeshima Y. Two closely spaced mutations in cis result in Ullrich congenital muscular dystrophy. Hum Genome Var 2019; 6:21. [PMID: 31044083 PMCID: PMC6486579 DOI: 10.1038/s41439-019-0052-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/25/2019] [Accepted: 04/02/2019] [Indexed: 11/11/2022] Open
Abstract
A 2-year-old boy was diagnosed with Ullrich congenital muscular dystrophy (UCMD) by muscle biopsy. COL6A3 gene analysis by next-generation sequencing revealed two heterozygous splice-site mutations (c.6283-1 G > G/T and c.6310-2 A > A/T), whereas normal mRNA was produced. Genomic DNA analysis revealed two mutations located on the same allele; however, no mutation was detected in either parent. These results indicated that two closely spaced de novo mutations resulted in the autosomal dominant UCMD.
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Affiliation(s)
- Hideki Shimomura
- 1Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Tomoko Lee
- 1Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Yasuhiko Tanaka
- 1Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Hiroyuki Awano
- 2Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kyoko Itoh
- 3Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ichizo Nishino
- 4Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yasuhiro Takeshima
- 1Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
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23
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Yee BA, Pratt GA, Graveley BR, Van Nostrand EL, Yeo GW. RBP-Maps enables robust generation of splicing regulatory maps. RNA (NEW YORK, N.Y.) 2019; 25:193-204. [PMID: 30413564 PMCID: PMC6348990 DOI: 10.1261/rna.069237.118] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/01/2018] [Indexed: 05/22/2023]
Abstract
Alternative splicing of pre-messenger RNA transcripts enables the generation of multiple protein isoforms from the same gene locus, providing a major source of protein diversity in mammalian genomes. RNA binding proteins (RBPs) bind to RNA to control splice site choice and define which exons are included in the resulting mature RNA transcript. However, depending on where the RBPs bind relative to splice sites, they can activate or repress splice site usage. To explore this position-specific regulation, in vivo binding sites identified by methods such as cross-linking and immunoprecipitation (CLIP) are integrated with alternative splicing events identified by RNA-seq or microarray. Merging these data sets enables the generation of a "splicing map," where CLIP signal relative to a merged meta-exon provides a simple summary of the position-specific effect of binding on splicing regulation. Here, we provide RBP-Maps, a software tool to simplify generation of these maps and enable researchers to rapidly query regulatory patterns of an RBP of interest. Further, we discuss various alternative approaches to generate such splicing maps, focusing on how decisions in construction (such as the use of peak versus read density, or whole-reads versus only single-nucleotide candidate crosslink positions) can affect the interpretation of these maps using example eCLIP data from the 150 RBPs profiled by the ENCODE consortium.
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Affiliation(s)
- Brian A Yee
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Gabriel A Pratt
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Bioinformatics and Systems Biology Graduate Program, University of California at San Diego, La Jolla, California 92093, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Health, Farmington, Connecticut 06030, USA
| | - Eric L Van Nostrand
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California at San Diego, La Jolla, California 92093, USA
- Bioinformatics and Systems Biology Graduate Program, University of California at San Diego, La Jolla, California 92093, USA
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24
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Kanitz A, Syed AP, Kaji K, Zavolan M. Conserved regulation of RNA processing in somatic cell reprogramming. BMC Genomics 2019; 20:100. [PMID: 30704403 PMCID: PMC6357513 DOI: 10.1186/s12864-019-5438-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 01/08/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Along with the reorganization of epigenetic and transcriptional networks, somatic cell reprogramming brings about numerous changes at the level of RNA processing. These include the expression of specific transcript isoforms and 3' untranslated regions. A number of studies have uncovered RNA processing factors that modulate the efficiency of the reprogramming process. However, a comprehensive evaluation of the involvement of RNA processing factors in the reprogramming of somatic mammalian cells is lacking. RESULTS Here, we used data from a large number of studies carried out in three mammalian species, mouse, chimpanzee and human, to uncover consistent changes in gene expression upon reprogramming of somatic cells. We found that a core set of nine splicing factors have consistent changes across the majority of data sets in all three species. Most striking among these are ESRP1 and ESRP2, which accelerate and enhance the efficiency of somatic cell reprogramming by promoting isoform expression changes associated with mesenchymal-to-epithelial transition. We further identify genes and processes in which splicing changes are observed in both human and mouse. CONCLUSIONS Our results provide a general resource for gene expression and splicing changes that take place during somatic cell reprogramming. Furthermore, they support the concept that splicing factors with evolutionarily conserved, cell type-specific expression can modulate the efficiency of the process by reinforcing intermediate states resembling the cell types in which these factors are normally expressed.
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Affiliation(s)
- Alexander Kanitz
- Biozentrum, University of Basel, Basel, Switzerland
- RNA Regulatory Networks, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Afzal Pasha Syed
- Biozentrum, University of Basel, Basel, Switzerland
- RNA Regulatory Networks, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Keisuke Kaji
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, Scotland, UK
| | - Mihaela Zavolan
- Biozentrum, University of Basel, Basel, Switzerland
- RNA Regulatory Networks, Swiss Institute of Bioinformatics, Lausanne, Switzerland
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25
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Suppression of prostate tumor cell survival by antisense oligonucleotide-mediated inhibition of AR-V7 mRNA synthesis. Oncogene 2019; 38:3696-3709. [PMID: 30664691 PMCID: PMC6756119 DOI: 10.1038/s41388-019-0696-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/12/2018] [Accepted: 01/04/2019] [Indexed: 12/19/2022]
Abstract
One of the mechanisms by which advanced prostate cancer develops resistance to androgen deprivation therapy is the elevated expression of C-terminally truncated androgen receptor (AR) variants. These variants, such as AR-V7, originate from aberrant splicing of the AR pre-mRNA and the inclusion of a cryptic exon containing a premature stop codon in the mRNA. The resulting loss of the ligand-binding domain allows AR-V7 to act as a constitutively active transcription factor. Here, we designed two antisense oligonucleotides (AONs) directed against cryptic splicing signals within the AR pre-mRNA. These two AONs, AON-ISE and AON-ESE, demonstrated high efficiency in silencing AR-V7 splicing without affecting full-length AR expression. The subsequent downregulation of AR-V7-target gene UBE2C was accompanied by inhibition of androgen-independent cell proliferation and induction of apoptosis in castration-resistant prostate cancer (CRPC)-derived cell line models 22Rv1, DuCaP, and VCaP. Our results show that splicing-directed AONs can efficiently prevent expression of AR-V7, providing an attractive new therapeutic option for the treatment of CRPC.
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26
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Xie Z, Tang Y, Su X, Cao J, Zhang Y, Li H. PAX3-FOXO1 escapes miR-495 regulation during muscle differentiation. RNA Biol 2019; 16:144-153. [PMID: 30593263 DOI: 10.1080/15476286.2018.1564464] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Pax3 plays an essential role in myogenesis. Previously, we found a tumor-signature chimeric fusion RNA, PAX3-FOXO1 also present during muscle differentiation, raising the possibility of its physiological role. Here we demonstrated that the fusion is needed transiently for muscle lineage commitment. Interestingly, the fusion ortholog was not found in seven mouse muscle differentiation/regeneration systems, nor in other stem cell differentiation systems of another three mammal species. We noticed that Pax3 is expressed at a much lower level in human stem cells, and during muscle differentiation than in other mammals. Given the fact that the fusion and the parental Pax3 share common downstream targets, we reasoned that forming the fusion may be a mechanism for human cells to escape certain microRNA regulation on Pax3. By sequence comparison, we identified 16 candidate microRNAs that may specifically target the human PAX3 3'UTR. We used a luciferase reporter assay, examined the microRNAs expression, and conducted mutagenesis on the reporters, as well as a CRISPR/Cas9 mediated editing on the endogenous allele. Finally, we identified miR-495 as a microRNA that specifically targets human PAX3. Examining several other fusion RNAs revealed that the human-specificity is not limited to PAX3-FOXO1. Based on these observations, we conclude that PAX3-FOXO1 fusion RNA is absent in mouse, or other mammals we tested, the fusion RNA is a mechanism to escape microRNA, miR-495 regulation in humans, and that it is not the only human-specific fusion RNA.
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Affiliation(s)
- Zhongqiu Xie
- a Department of Pathology , University of Virginia , Charlottesville , VA , USA
| | - Yue Tang
- a Department of Pathology , University of Virginia , Charlottesville , VA , USA.,b College of Life Sciences , Zhengzhou University , Zhengzhou , Henan , P. R. China
| | - Xiaohu Su
- c College of Life Sciences , Inner Mongolia Agricultural University , Hohhot , Inner Mongolia , China.,d Key Laboratory of Biological Manufacturing of Inner Mongolia Autonomous Region , Hohhot , Inner Mongolia , China
| | - Junwei Cao
- a Department of Pathology , University of Virginia , Charlottesville , VA , USA.,c College of Life Sciences , Inner Mongolia Agricultural University , Hohhot , Inner Mongolia , China.,d Key Laboratory of Biological Manufacturing of Inner Mongolia Autonomous Region , Hohhot , Inner Mongolia , China
| | - Yanru Zhang
- c College of Life Sciences , Inner Mongolia Agricultural University , Hohhot , Inner Mongolia , China.,d Key Laboratory of Biological Manufacturing of Inner Mongolia Autonomous Region , Hohhot , Inner Mongolia , China
| | - Hui Li
- a Department of Pathology , University of Virginia , Charlottesville , VA , USA.,b College of Life Sciences , Zhengzhou University , Zhengzhou , Henan , P. R. China.,e University of Virginia Cancer Center , Charlottesville , VA , USA
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27
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Wai H, Douglas AGL, Baralle D. RNA splicing analysis in genomic medicine. Int J Biochem Cell Biol 2018; 108:61-71. [PMID: 30594648 DOI: 10.1016/j.biocel.2018.12.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/03/2018] [Accepted: 12/14/2018] [Indexed: 12/13/2022]
Abstract
High-throughput next-generation sequencing technologies have led to a rapid increase in the number of sequence variants identified in clinical practice via diagnostic genetic tests. Current bioinformatic analysis pipelines fail to take adequate account of the possible splicing effects of such variants, particularly where variants fall outwith canonical splice site sequences, and consequently the pathogenicity of such variants may often be missed. The regulation of splicing is highly complex and as a result, in silico prediction tools lack sufficient sensitivity and specificity for reliable use. Variants of all kinds can be linked to aberrant splicing in disease and the need for correct identification and diagnosis grows ever more crucial as novel splice-switching antisense oligonucleotide therapies start to enter clinical usage. RT-PCR provides a useful targeted assay of the splicing effects of identified variants, while minigene assays, massive parallel reporter assays and animal models can also be used for more detailed study of a particular splicing system, given enough time and resources. However, RNA-sequencing (RNA-seq) has the potential to be used as a rapid diagnostic tool in genomic medicine. By utilising data science approaches and machine learning, it may prove possible to finally understand and interpret the 'splicing code' and apply this knowledge in human disease diagnostics.
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Affiliation(s)
- Htoo Wai
- Human Development and Health, Faculty of Medicine, University of Southampton, UK
| | - Andrew G L Douglas
- Human Development and Health, Faculty of Medicine, University of Southampton, UK; Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, UK; Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
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28
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Dissecting the Contributions of Cooperating Gene Mutations to Cancer Phenotypes and Drug Responses with Patient-Derived iPSCs. Stem Cell Reports 2018; 10:1610-1624. [PMID: 29681544 PMCID: PMC5995368 DOI: 10.1016/j.stemcr.2018.03.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/23/2018] [Accepted: 03/23/2018] [Indexed: 12/30/2022] Open
Abstract
Connecting specific cancer genotypes with phenotypes and drug responses constitutes the central premise of precision oncology but is hindered by the genetic complexity and heterogeneity of primary cancer cells. Here, we use patient-derived induced pluripotent stem cells (iPSCs) and CRISPR/Cas9 genome editing to dissect the individual contributions of two recurrent genetic lesions, the splicing factor SRSF2 P95L mutation and the chromosome 7q deletion, to the development of myeloid malignancy. Using a comprehensive panel of isogenic iPSCs-with none, one, or both genetic lesions-we characterize their relative phenotypic contributions and identify drug sensitivities specific to each one through a candidate drug approach and an unbiased large-scale small-molecule screen. To facilitate drug testing and discovery, we also derive SRSF2-mutant and isogenic normal expandable hematopoietic progenitor cells. We thus describe here an approach to dissect the individual effects of two cooperating mutations to clinically relevant features of malignant diseases.
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29
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Park E, Pan Z, Zhang Z, Lin L, Xing Y. The Expanding Landscape of Alternative Splicing Variation in Human Populations. Am J Hum Genet 2018; 102:11-26. [PMID: 29304370 PMCID: PMC5777382 DOI: 10.1016/j.ajhg.2017.11.002] [Citation(s) in RCA: 224] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/03/2017] [Indexed: 12/16/2022] Open
Abstract
Alternative splicing is a tightly regulated biological process by which the number of gene products for any given gene can be greatly expanded. Genomic variants in splicing regulatory sequences can disrupt splicing and cause disease. Recent developments in sequencing technologies and computational biology have allowed researchers to investigate alternative splicing at an unprecedented scale and resolution. Population-scale transcriptome studies have revealed many naturally occurring genetic variants that modulate alternative splicing and consequently influence phenotypic variability and disease susceptibility in human populations. Innovations in experimental and computational tools such as massively parallel reporter assays and deep learning have enabled the rapid screening of genomic variants for their causal impacts on splicing. In this review, we describe technological advances that have greatly increased the speed and scale at which discoveries are made about the genetic variation of alternative splicing. We summarize major findings from population transcriptomic studies of alternative splicing and discuss the implications of these findings for human genetics and medicine.
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Affiliation(s)
- Eddie Park
- Department of Microbiology, Immunology, & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Zhicheng Pan
- Bioinformatics Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Zijun Zhang
- Bioinformatics Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lan Lin
- Department of Microbiology, Immunology, & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yi Xing
- Department of Microbiology, Immunology, & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; Bioinformatics Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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30
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Murphy PA, Butty VL, Boutz PL, Begum S, Kimble AL, Sharp PA, Burge CB, Hynes RO. Alternative RNA splicing in the endothelium mediated in part by Rbfox2 regulates the arterial response to low flow. eLife 2018; 7:29494. [PMID: 29293084 PMCID: PMC5771670 DOI: 10.7554/elife.29494] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 12/30/2017] [Indexed: 12/13/2022] Open
Abstract
Low and disturbed blood flow drives the progression of arterial diseases including atherosclerosis and aneurysms. The endothelial response to flow and its interactions with recruited platelets and leukocytes determine disease progression. Here, we report widespread changes in alternative splicing of pre-mRNA in the flow-activated murine arterial endothelium in vivo. Alternative splicing was suppressed by depletion of platelets and macrophages recruited to the arterial endothelium under low and disturbed flow. Binding motifs for the Rbfox-family are enriched adjacent to many of the regulated exons. Endothelial deletion of Rbfox2, the only family member expressed in arterial endothelium, suppresses a subset of the changes in transcription and RNA splicing induced by low flow. Our data reveal an alternative splicing program activated by Rbfox2 in the endothelium on recruitment of platelets and macrophages and demonstrate its relevance in transcriptional responses during flow-driven vascular inflammation.
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Affiliation(s)
- Patrick A Murphy
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, United States
| | | | - Paul L Boutz
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, United States
| | - Shahinoor Begum
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, United States.,Howard Hughes Medical Institute, United States
| | - Amy L Kimble
- Center for Vascular Biology, UCONN Health, Farmington, United States
| | - Phillip A Sharp
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, United States.,Department of Biology, MIT, Cambridge, United States
| | | | - Richard O Hynes
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, United States.,Department of Biology, MIT, Cambridge, United States.,Howard Hughes Medical Institute, United States
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31
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Bush SJ, Chen L, Tovar-Corona JM, Urrutia AO. Alternative splicing and the evolution of phenotypic novelty. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0474. [PMID: 27994117 DOI: 10.1098/rstb.2015.0474] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
Alternative splicing, a mechanism of post-transcriptional RNA processing whereby a single gene can encode multiple distinct transcripts, has been proposed to underlie morphological innovations in multicellular organisms. Genes with developmental functions are enriched for alternative splicing events, suggestive of a contribution of alternative splicing to developmental programmes. The role of alternative splicing as a source of transcript diversification has previously been compared to that of gene duplication, with the relationship between the two extensively explored. Alternative splicing is reduced following gene duplication with the retention of duplicate copies higher for genes which were alternatively spliced prior to duplication. Furthermore, and unlike the case for overall gene number, the proportion of alternatively spliced genes has also increased in line with the evolutionary diversification of cell types, suggesting alternative splicing may contribute to the complexity of developmental programmes. Together these observations suggest a prominent role for alternative splicing as a source of functional innovation. However, it is unknown whether the proliferation of alternative splicing events indeed reflects a functional expansion of the transcriptome or instead results from weaker selection acting on larger species, which tend to have a higher number of cell types and lower population sizes.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
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Affiliation(s)
- Stephen J Bush
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Lu Chen
- West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, People's Republic of China
| | | | - Araxi O Urrutia
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK .,Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK
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32
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Zhou B, Wang GZ, Wen ZS, Zhou YC, Huang YC, Chen Y, Zhou GB. Somatic Mutations and Splicing Variants of Focal Adhesion Kinase in Non–Small Cell Lung Cancer. J Natl Cancer Inst 2017; 110:4565750. [PMID: 29087503 DOI: 10.1093/jnci/djx157] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 06/30/2017] [Indexed: 12/17/2022] Open
Affiliation(s)
- Bo Zhou
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences and University of Chinese Academy of Sciences, Beijing, China
| | - Gui-Zhen Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences and University of Chinese Academy of Sciences, Beijing, China
| | - Zhe-Sheng Wen
- Department of Thoracic Surgery, the Cancer Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yong-Chun Zhou
- Department of Thoracic Surgery, the Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yun-Chao Huang
- Department of Thoracic Surgery, the Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Ying Chen
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Guang-Biao Zhou
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences and University of Chinese Academy of Sciences, Beijing, China
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33
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Gao R, Li JJ. Correspondence of D. melanogaster and C. elegans developmental stages revealed by alternative splicing characteristics of conserved exons. BMC Genomics 2017; 18:234. [PMID: 28302059 PMCID: PMC5353869 DOI: 10.1186/s12864-017-3600-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 02/22/2017] [Indexed: 11/21/2022] Open
Abstract
Background We report a statistical study to find correspondence of D. melanogaster and C. elegans developmental stages based on alternative splicing (AS) characteristics of conserved cassette exons using modENCODE RNA-seq data. We identify “stage-associated exons” to capture the AS characteristics of each stage and use these exons to map pairwise stages within and between the two species by an overlap test. Results Within fly and worm, adjacent developmental stages are mapped to each other, i.e., a strong diagonal pattern is observed as expected, supporting the validity of our approach. Between fly and worm, two parallel mapping patterns are observed between fly early embryos to early larvae and worm life cycle, and between fly late larvae to adults and worm late embryos to adults. We also apply this approach to compare tissues and cells from fly and worm. Findings include the high similarity between fly/worm adults and fly/worm embryos, groupings of fly cell lines, and strong mappings of fly head tissues to worm late embryos and male adults. Gene ontology and KEGG enrichment analyses provide a detailed functional annotation of the identified stage-associated exons, as well as a functional explanation of the observed correspondence map between fly and worm developmental stages. Conclusions Our results suggest that AS dynamics of the exon pairs that share similar DNA sequences are informative for finding transcriptomic similarity of biological samples. Our study is innovative in two aspects. First, to our knowledge, our study is the first comprehensive study of AS events in fly and worm developmental stages, tissues, and cells. AS events provide an alternative perspective of transcriptome dynamics, compared to gene expression events. Second, our results do not entirely rely on the information of orthologous genes. Interesting results are also observed for fly and worm cassette exon pairs with DNA sequence similarity but not in orthologous gene pairs. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3600-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ruiqi Gao
- Department of Statistics, University of California, Los Angeles, USA
| | - Jingyi Jessica Li
- Department of Statistics, University of California, Los Angeles, USA. .,Department of Human Genetics, University of California, Los Angeles, USA.
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34
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Lykens NM, Coughlin DJ, Reddi JM, Lutz GJ, Tallent MK. AMPA GluA1-flip targeted oligonucleotide therapy reduces neonatal seizures and hyperexcitability. PLoS One 2017; 12:e0171538. [PMID: 28178321 PMCID: PMC5298276 DOI: 10.1371/journal.pone.0171538] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 01/23/2017] [Indexed: 12/24/2022] Open
Abstract
Glutamate-activated α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-Rs) mediate the majority of excitatory neurotransmission in brain and thus are major drug targets for diseases associated with hyperexcitability or neurotoxicity. Due to the critical nature of AMPA-Rs in normal brain function, typical AMPA-R antagonists have deleterious effects on cognition and motor function, highlighting the need for more precise modulators. A dramatic increase in the flip isoform of alternatively spliced AMPA-R GluA1 subunits occurs post-seizure in humans and animal models. GluA1-flip produces higher gain AMPA channels than GluA1-flop, increasing network excitability and seizure susceptibility. Splice modulating oligonucleotides (SMOs) bind to pre-mRNA to influence alternative splicing, a strategy that can be exploited to develop more selective drugs across therapeutic areas. We developed a novel SMO, GR1, which potently and specifically decreased GluA1-flip expression throughout the brain of neonatal mice lasting at least 60 days after single intracerebroventricular injection. GR1 treatment reduced AMPA-R mediated excitatory postsynaptic currents at hippocampal CA1 synapses, without affecting long-term potentiation or long-term depression, cellular models of memory, or impairing GluA1-dependent cognition or motor function in mice. Importantly, GR1 demonstrated anti-seizure properties and reduced post-seizure hyperexcitability in neonatal mice, highlighting its drug candidate potential for treating epilepsies and other neurological diseases involving network hyperexcitability.
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Affiliation(s)
- Nicole M. Lykens
- Graduate Program in Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- LifeSplice Pharma, Malvern, Pennsylvania, United States of America
| | - David J. Coughlin
- Department of Biology, Widener University, Chester, Pennsylvania, United States of America
| | - Jyoti M. Reddi
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gordon J. Lutz
- LifeSplice Pharma, Malvern, Pennsylvania, United States of America
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Melanie K. Tallent
- LifeSplice Pharma, Malvern, Pennsylvania, United States of America
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Qiu J, Zhou B, Thol F, Zhou Y, Chen L, Shao C, DeBoever C, Hou J, Li H, Chaturvedi A, Ganser A, Bejar R, Zhang DE, Fu XD, Heuser M. Distinct splicing signatures affect converged pathways in myelodysplastic syndrome patients carrying mutations in different splicing regulators. RNA (NEW YORK, N.Y.) 2016; 22:1535-1549. [PMID: 27492256 PMCID: PMC5029452 DOI: 10.1261/rna.056101.116] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 06/08/2016] [Indexed: 06/06/2023]
Abstract
Myelodysplastic syndromes (MDS) are heterogeneous myeloid disorders with prevalent mutations in several splicing factors, but the splicing programs linked to specific mutations or MDS in general remain to be systematically defined. We applied RASL-seq, a sensitive and cost-effective platform, to interrogate 5502 annotated splicing events in 169 samples from MDS patients or healthy individuals. We found that splicing signatures associated with normal hematopoietic lineages are largely related to cell signaling and differentiation programs, whereas MDS-linked signatures are primarily involved in cell cycle control and DNA damage responses. Despite the shared roles of affected splicing factors in the 3' splice site definition, mutations in U2AF1, SRSF2, and SF3B1 affect divergent splicing programs, and interestingly, the affected genes fall into converging cancer-related pathways. A risk score derived from 11 splicing events appears to be independently associated with an MDS prognosis and AML transformation, suggesting potential clinical relevance of altered splicing patterns in MDS.
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Affiliation(s)
- Jinsong Qiu
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Bing Zhou
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Felicitas Thol
- Department of Hematology, Hemostasis, Oncology and Stem cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
| | - Yu Zhou
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Liang Chen
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Changwei Shao
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Christopher DeBoever
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Jiayi Hou
- Clinical and Translational Research Institute, University of California, San Diego, La Jolla, California 92093, USA
| | - Hairi Li
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Anuhar Chaturvedi
- Department of Hematology, Hemostasis, Oncology and Stem cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
| | - Arnold Ganser
- Department of Hematology, Hemostasis, Oncology and Stem cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
| | - Rafael Bejar
- Division of Hematology-Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, USA
| | - Dong-Er Zhang
- Department of Pathology, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, USA
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA Institute for Genomic Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Michael Heuser
- Department of Hematology, Hemostasis, Oncology and Stem cell Transplantation, Hannover Medical School, 30625 Hannover, Germany
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36
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Hane M, Kitajima K, Sato C. Effects of intronic single nucleotide polymorphisms (iSNPs) of a polysialyltransferase, ST8SIA2 gene found in psychiatric disorders on its gene products. Biochem Biophys Res Commun 2016; 478:1123-9. [DOI: 10.1016/j.bbrc.2016.08.079] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 08/12/2016] [Indexed: 01/06/2023]
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Gokce O, Stanley GM, Treutlein B, Neff NF, Camp JG, Malenka RC, Rothwell PE, Fuccillo MV, Südhof TC, Quake SR. Cellular Taxonomy of the Mouse Striatum as Revealed by Single-Cell RNA-Seq. Cell Rep 2016; 16:1126-1137. [PMID: 27425622 DOI: 10.1016/j.celrep.2016.06.059] [Citation(s) in RCA: 267] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 05/13/2016] [Accepted: 06/11/2016] [Indexed: 11/28/2022] Open
Abstract
The striatum contributes to many cognitive processes and disorders, but its cell types are incompletely characterized. We show that microfluidic and FACS-based single-cell RNA sequencing of mouse striatum provides a well-resolved classification of striatal cell type diversity. Transcriptome analysis revealed ten differentiated, distinct cell types, including neurons, astrocytes, oligodendrocytes, ependymal, immune, and vascular cells, and enabled the discovery of numerous marker genes. Furthermore, we identified two discrete subtypes of medium spiny neurons (MSNs) that have specific markers and that overexpress genes linked to cognitive disorders and addiction. We also describe continuous cellular identities, which increase heterogeneity within discrete cell types. Finally, we identified cell type-specific transcription and splicing factors that shape cellular identities by regulating splicing and expression patterns. Our findings suggest that functional diversity within a complex tissue arises from a small number of discrete cell types, which can exist in a continuous spectrum of functional states.
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Affiliation(s)
- Ozgun Gokce
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität LMU, 81377 Munich, Germany
| | - Geoffrey M Stanley
- Biophysics Program, Stanford University, Stanford, CA 94305, USA; Departments of Bioengineering and Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Barbara Treutlein
- Departments of Bioengineering and Applied Physics, Stanford University, Stanford, CA 94305, USA; Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Norma F Neff
- Departments of Bioengineering and Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - J Gray Camp
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Robert C Malenka
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Patrick E Rothwell
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Marc V Fuccillo
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
| | - Stephen R Quake
- Departments of Bioengineering and Applied Physics, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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Abstract
The recent genomic characterization of cancers has revealed recurrent somatic point mutations and copy number changes affecting genes encoding RNA splicing factors. Initial studies of these 'spliceosomal mutations' suggest that the proteins bearing these mutations exhibit altered splice site and/or exon recognition preferences relative to their wild-type counterparts, resulting in cancer-specific mis-splicing. Such changes in the splicing machinery may create novel vulnerabilities in cancer cells that can be therapeutically exploited using compounds that can influence the splicing process. Further studies to dissect the biochemical, genomic and biological effects of spliceosomal mutations are crucial for the development of cancer therapies targeted at these mutations.
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Affiliation(s)
- Heidi Dvinge
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Eunhee Kim
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Leukemia Service, Dept. of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Robert K. Bradley
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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39
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Gonzalez-Paredes FJ, Ramos-Trujillo E, Claverie-Martin F. Three exonic mutations in polycystic kidney disease-2 gene (PKD2) alter splicing of its pre-mRNA in a minigene system. Gene 2016; 578:117-23. [DOI: 10.1016/j.gene.2015.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/05/2015] [Accepted: 12/07/2015] [Indexed: 11/25/2022]
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40
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Horan L, Yasuhara JC, Kohlstaedt LA, Rio DC. Biochemical identification of new proteins involved in splicing repression at the Drosophila P-element exonic splicing silencer. Genes Dev 2016; 29:2298-311. [PMID: 26545814 PMCID: PMC4647562 DOI: 10.1101/gad.268847.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Splicing of the Drosophila P-element third intron (IVS3) is repressed in somatic tissues due to the function of an exonic splicing silencer (ESS) complex present on the 5' exon RNA. To comprehensively characterize the mechanisms of this alternative splicing regulation, we used biochemical fractionation and affinity purification to isolate the silencer complex assembled in vitro and identify the constituent proteins by mass spectrometry. Functional assays using splicing reporter minigenes identified the proteins hrp36 and hrp38 and the cytoplasmic poly(A)-binding protein PABPC1 as novel functional components of the splicing silencer. hrp48, PSI, and PABPC1 have high-affinity RNA-binding sites on the P-element IVS3 5' exon, whereas hrp36 and hrp38 proteins bind with low affinity to the P-element silencer RNA. RNA pull-down and immobilized protein assays showed that hrp48 protein binding to the silencer RNA can recruit hrp36 and hrp38. These studies identified additional components that function at the P-element ESS and indicated that proteins with low-affinity RNA-binding sites can be recruited in a functional manner through interactions with a protein bound to RNA at a high-affinity binding site. These studies have implications for the role of heterogeneous nuclear ribonucleoproteins (hnRNPs) in the control of alternative splicing at cis-acting regulatory sites.
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Affiliation(s)
- Lucas Horan
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Jiro C Yasuhara
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Lori A Kohlstaedt
- California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, California 94720, USA
| | - Donald C Rio
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA; California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, California 94720, USA; Center for RNA Systems Biology, University of California at Berkeley, Berkeley, California 94720, USA
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41
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Ruble CL, Smith RM, Calley J, Munsie L, Airey DC, Gao Y, Shin JH, Hyde TM, Straub RE, Weinberger DR, Nisenbaum LK. Genomic structure and expression of the human serotonin 2A receptor gene (HTR2A) locus: identification of novel HTR2A and antisense (HTR2A-AS1) exons. BMC Genet 2016; 17:16. [PMID: 26738766 PMCID: PMC4702415 DOI: 10.1186/s12863-015-0325-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/22/2015] [Indexed: 01/16/2023] Open
Abstract
Background The serotonin 2A receptor is widely implicated in genetic association studies and remains an important drug target for psychiatric, neurological, and cardiovascular conditions. RNA sequencing redefined the architecture of the serotonin 2A receptor gene (HTR2A), revealing novel mRNA transcript isoforms utilizing unannotated untranslated regions of the gene. Expression of these untranslated regions is modulated by common single nucleotide polymorphisms (SNPs), namely rs6311. Previous studies did not fully capture the complexity of the sense- and antisense-encoded transcripts with respect to novel exons in the HTR2A gene locus. Here, we comprehensively catalogued exons and RNA isoforms for both HTR2A and HTR2A-AS1 using RNA-Seq from human prefrontal cortex and multiple mouse tissues. We subsequently tested associations between expression of newfound gene features and common SNPs in humans. Results We find that the human HTR2A gene spans ~66 kilobases and consists of 7, rather than 4 exons. Furthermore, the revised human HTR2A-AS1 gene spans ~474 kilobases and consists of 18, rather than 3 exons. Three HTR2A exons directly overlap with HTR2A-AS1 exons, suggesting potential for complementary nucleotide interactions. The repertoire of possible mouse Htr2a splice isoforms is remarkably similar to humans and we also find evidence for overlapping sense-antisense transcripts in the same relative positions as the human transcripts. rs6311 and SNPs in high linkage disequilibrium are associated with HTR2A-AS1 expression, in addition to previously described associations with expression of the extended 5’ untranslated region of HTR2A. Conclusions Our proposed HTR2A and HTR2A-AS1 gene structures dramatically differ from current annotations, now including overlapping exons on the sense and anti-sense strands. We also find orthologous transcript isoforms expressed in mice, providing opportunities to elucidate the biological roles of the human isoforms using a model system. Associations between rs6311 and expression of HTR2A and HTR2A-AS1 suggest this polymorphism is capable of modulating the expression of the sense or antisense transcripts. Still unclear is whether these SNPs act directly on the expression of the sense or antisense transcripts and whether overlapping exons are capable of interacting through complimentary base-pairing. Additional studies are necessary to determine the extent and nature of interactions between the SNPs and the transcripts prior to interpreting these findings in the context of phenotypes associated with HTR2A. Electronic supplementary material The online version of this article (doi:10.1186/s12863-015-0325-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cara L Ruble
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Ryan M Smith
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - John Calley
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Leanne Munsie
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - David C Airey
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Yuan Gao
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ.
| | - Joo Heon Shin
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ.
| | - Thomas M Hyde
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ. .,Departments of Neurology, Psychiatry and Behavioral Sciences, John Hopkins University School of Medicine, Baltimore, MD, ᅟ.
| | | | - Daniel R Weinberger
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ. .,Departments of Psychiatry, Neurology, Neuroscience, and the Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, ᅟ.
| | - Laura K Nisenbaum
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
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Experimental and Computational Considerations in the Study of RNA-Binding Protein-RNA Interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 907:1-28. [PMID: 27256380 DOI: 10.1007/978-3-319-29073-7_1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
After an RNA is transcribed, it undergoes a variety of processing steps that can change the encoded protein sequence (through alternative splicing and RNA editing), regulate the stability of the RNA, and control subcellular localization, timing, and rate of translation. The recent explosion in genomics techniques has enabled transcriptome-wide profiling of RNA processing in an unbiased manner. However, it has also brought with it both experimental challenges in developing improved methods to probe distinct processing steps, as well as computational challenges in data storage, processing, and analysis tools to enable large-scale interpretation in the genomics era. In this chapter we review experimental techniques and challenges in profiling various aspects of RNA processing, as well as recent efforts to develop analyses integrating multiple data sources and techniques to infer RNA regulatory networks.
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Abascal F, Tress ML, Valencia A. The evolutionary fate of alternatively spliced homologous exons after gene duplication. Genome Biol Evol 2015; 7:1392-403. [PMID: 25931610 PMCID: PMC4494069 DOI: 10.1093/gbe/evv076] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Alternative splicing and gene duplication are the two main processes responsible for expanding protein functional diversity. Although gene duplication can generate new genes and alternative splicing can introduce variation through alternative gene products, the interplay between the two processes is complex and poorly understood. Here, we have carried out a study of the evolution of alternatively spliced exons after gene duplication to better understand the interaction between the two processes. We created a manually curated set of 97 human genes with mutually exclusively spliced homologous exons and analyzed the evolution of these exons across five distantly related vertebrates (lamprey, spotted gar, zebrafish, fugu, and coelacanth). Most of these exons had an ancient origin (more than 400 Ma). We found examples supporting two extreme evolutionary models for the behaviour of homologous axons after gene duplication. We observed 11 events in which gene duplication was accompanied by splice isoform separation, that is, each paralog specifically conserved just one distinct ancestral homologous exon. At other extreme, we identified genes in which the homologous exons were always conserved within paralogs, suggesting that the alternative splicing event cannot easily be separated from the function in these genes. That many homologous exons fall in between these two extremes highlights the diversity of biological systems and suggests that the subtle balance between alternative splicing and gene duplication is adjusted to the specific cellular context of each gene.
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Affiliation(s)
- Federico Abascal
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Michael L Tress
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Alfonso Valencia
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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44
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Merkin JJ, Chen P, Alexis MS, Hautaniemi SK, Burge CB. Origins and impacts of new mammalian exons. Cell Rep 2015; 10:1992-2005. [PMID: 25801031 DOI: 10.1016/j.celrep.2015.02.058] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/09/2015] [Accepted: 02/23/2015] [Indexed: 02/08/2023] Open
Abstract
Mammalian genes are composed of exons, but the evolutionary origins and functions of new internal exons are poorly understood. Here, we analyzed patterns of exon gain using deep cDNA sequencing data from five mammals and one bird, identifying thousands of species- and lineage-specific exons. Most new exons derived from unique rather than repetitive intronic sequence. Unlike exons conserved across mammals, species-specific internal exons were mostly located in 5' UTRs and alternatively spliced. They were associated with upstream intronic deletions, increased nucleosome occupancy, and RNA polymerase II pausing. Genes containing new internal exons had increased gene expression, but only in tissues in which the exon was included. Increased expression correlated with the level of exon inclusion, promoter proximity, and signatures of cotranscriptional splicing. Altogether, these findings suggest that increased splicing at the 5' ends of genes enhances expression and that changes in 5' end splicing alter gene expression between tissues and between species.
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Affiliation(s)
- Jason J Merkin
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Ping Chen
- Research Programs Unit, Genome-Scale Biology and Institute of Biomedicine, University of Helsinki, 00014 Helsinki, Finland
| | - Maria S Alexis
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Program in Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Sampsa K Hautaniemi
- Research Programs Unit, Genome-Scale Biology and Institute of Biomedicine, University of Helsinki, 00014 Helsinki, Finland
| | - Christopher B Burge
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Program in Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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45
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Chuang TJ, Yang MY, Lin CC, Hsieh PH, Hung LY. Comparative genomics of grass EST libraries reveals previously uncharacterized splicing events in crop plants. BMC PLANT BIOLOGY 2015; 15:39. [PMID: 25652661 PMCID: PMC4323234 DOI: 10.1186/s12870-015-0431-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/20/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Crop plants such as rice, maize and sorghum play economically-important roles as main sources of food, fuel, and animal feed. However, current genome annotations of crop plants still suffer false-positive predictions; a more comprehensive registry of alternative splicing (AS) events is also in demand. Comparative genomics of crop plants is largely unexplored. RESULTS We performed a large-scale comparative analysis (ExonFinder) of the expressed sequence tag (EST) library from nine grass plants against three crop genomes (rice, maize, and sorghum) and identified 2,879 previously-unannotated exons (i.e., novel exons) in the three crops. We validated 81% of the tested exons by RT-PCR-sequencing, supporting the effectiveness of our in silico strategy. Evolutionary analysis reveals that the novel exons, comparing with their flanking annotated ones, are generally under weaker selection pressure at the protein level, but under stronger pressure at the RNA level, suggesting that most of the novel exons also represent novel alternatively spliced variants (ASVs). However, we also observed the consistency of evolutionary rates between certain novel exons and their flanking exons, which provided further evidence of their co-occurrence in the transcripts, suggesting that previously-annotated isoforms might be subject to erroneous predictions. Our validation showed that 54% of the tested genes expressed the newly-identified isoforms that contained the novel exons, rather than the previously-annotated isoforms that excluded them. The consistent results were steadily observed across cultivated (Oryza sativa and O. glaberrima) and wild (O. rufipogon and O. nivara) rice species, asserting the necessity of our curation of the crop genome annotations. Our comparative analyses also inferred the common ancestral transcriptome of grass plants and gain- and loss-of-ASV events. CONCLUSIONS We have reannotated the rice, maize, and sorghum genomes, and showed that evolutionary rates might serve as an indicator for determining whether the identified exons were alternatively spliced. This study not only presents an effective in silico strategy for the improvement of plant annotations, but also provides further insights into the role of AS events in the evolution and domestication of crop plants. ExonFinder and the novel exons/ASVs identified are publicly accessible at http://exonfinder.sourceforge.net/ .
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Affiliation(s)
| | - Min-Yu Yang
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
| | - Chuang-Chieh Lin
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
| | - Ping-Hung Hsieh
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
| | - Li-Yuan Hung
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
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Soemedi R, Vega H, Belmont JM, Ramachandran S, Fairbrother WG. Genetic variation and RNA binding proteins: tools and techniques to detect functional polymorphisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:227-66. [PMID: 25201108 DOI: 10.1007/978-1-4939-1221-6_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
At its most fundamental level the goal of genetics is to connect genotype to phenotype. This question is asked at a basic level evaluating the role of genes and pathways in genetic model organism. Increasingly, this question is being asked in the clinic. Genomes of individuals and populations are being sequenced and compared. The challenge often comes at the stage of analysis. The variant positions are analyzed with the hope of understanding human disease. However after a genome or exome has been sequenced, the researcher is often deluged with hundreds of potentially relevant variations. Traditionally, amino-acid changing mutations were considered the tractable class of disease-causing mutations; however, mutations that disrupt noncoding elements are the subject of growing interest. These noncoding changes are a major avenue of disease (e.g., one in three hereditary disease alleles are predicted to affect splicing). Here, we review some current practices of medical genetics, the basic theory behind biochemical binding and functional assays, and then explore technical advances in how variations that alter RNA protein recognition events are detected and studied. These advances are advances in scale-high-throughput implementations of traditional biochemical assays that are feasible to perform in any molecular biology laboratory. This chapter utilizes a case study approach to illustrate some methods for analyzing polymorphisms. The first characterizes a functional intronic SNP that deletes a high affinity PTB site using traditional low-throughput biochemical and functional assays. From here we demonstrate the utility of high-throughput splicing and spliceosome assembly assays for screening large sets of SNPs and disease alleles for allelic differences in gene expression. Finally we perform three pilot drug screens with small molecules (G418, tetracycline, and valproic acid) that illustrate how compounds that rescue specific instances of differential pre-mRNA processing can be discovered.
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Affiliation(s)
- Rachel Soemedi
- Center for Computational Molecular Biology, Brown University, Providence, RI, USA
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Vanhoutteghem A, Messiaen S, Hervé F, Delhomme B, Moison D, Petit JM, Rouiller-Fabre V, Livera G, Djian P. The zinc-finger protein basonuclin 2 is required for proper mitotic arrest, prevention of premature meiotic initiation and meiotic progression in mouse male germ cells. Development 2014; 141:4298-310. [PMID: 25344072 DOI: 10.1242/dev.112888] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Absence of mitosis and meiosis are distinguishing properties of male germ cells during late fetal and early neonatal periods. Repressors of male germ cell meiosis have been identified, but mitotic repressors are largely unknown, and no protein repressing both meiosis and mitosis is known. We demonstrate here that the zinc-finger protein BNC2 is present in male but not in female germ cells. In testis, BNC2 exists as several spliced isoforms and presumably binds to DNA. Within the male germ cell lineage, BNC2 is restricted to prospermatogonia and undifferentiated spermatogonia. Fetal prospermatogonia that lack BNC2 multiply excessively on embryonic day (E)14.5 and reenter the cell cycle prematurely. Mutant prospermatogonia also engage in abnormal meiosis; on E17.5, Bnc2(-/-) prospermatogonia start synthesizing the synaptonemal protein SYCP3, and by the time of birth, many Bnc2(-/-) prospermatogonia have accumulated large amounts of nonfilamentous SYCP3, thus appearing to be blocked at leptonema. Bnc2(-/-) prospermatogonia do not undergo proper male differentiation, as they lack almost all the mRNA for the male-specific methylation protein DNMT3L and have increased levels of mRNAs that encode meiotic proteins, including STRA8. Bnc2(-/-) prospermatogonia can produce spermatogonia, but these enter meiosis prematurely and undergo massive apoptotic death during meiotic prophase. This study identifies BNC2 as a major regulator of male germ stem cells, which is required for repression of meiosis and mitosis in prospermatogonia, and for meiosis progression during spermatogenesis. In view of the extreme evolutionary conservation of BNC2, the findings described here are likely to apply to many species.
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Affiliation(s)
- Amandine Vanhoutteghem
- Laboratoire de physiologie cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, UMR 8118, Paris, France
| | - Sébastien Messiaen
- Laboratoire de développement des gonades, Université Paris Diderot, Sorbonne Paris Cité, INSERM U967, CEA/DSV/iRCM/SCSR, Fontenay-aux-Roses F-92265, France
| | - Françoise Hervé
- Laboratoire de physiologie cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, UMR 8118, Paris, France
| | - Brigitte Delhomme
- Laboratoire de physiologie cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, UMR 8118, Paris, France
| | - Delphine Moison
- Laboratoire de développement des gonades, Université Paris Diderot, Sorbonne Paris Cité, INSERM U967, CEA/DSV/iRCM/SCSR, Fontenay-aux-Roses F-92265, France
| | - Jean-Maurice Petit
- Service central de microscopie, Centre Universitaire des Saints-Pères, Université Paris Descartes, Paris, France
| | - Virginie Rouiller-Fabre
- Laboratoire de développement des gonades, Université Paris Diderot, Sorbonne Paris Cité, INSERM U967, CEA/DSV/iRCM/SCSR, Fontenay-aux-Roses F-92265, France
| | - Gabriel Livera
- Laboratoire de développement des gonades, Université Paris Diderot, Sorbonne Paris Cité, INSERM U967, CEA/DSV/iRCM/SCSR, Fontenay-aux-Roses F-92265, France
| | - Philippe Djian
- Laboratoire de physiologie cérébrale, Centre National de la Recherche Scientifique, Université Paris Descartes, UMR 8118, Paris, France
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48
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Boddu R, Yang C, O’Connor AK, Hendrickson RC, Boone B, Cui X, Garcia-Gonzalez M, Igarashi P, Onuchic LF, Germino GG, Guay-Woodford LM. Intragenic motifs regulate the transcriptional complexity of Pkhd1/PKHD1. J Mol Med (Berl) 2014; 92:1045-56. [PMID: 24984783 PMCID: PMC4197071 DOI: 10.1007/s00109-014-1185-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/05/2014] [Accepted: 06/16/2014] [Indexed: 11/26/2022]
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) results from mutations in the human PKHD1 gene. Both this gene, and its mouse ortholog, Pkhd1, are primarily expressed in renal and biliary ductal structures. The mouse protein product, fibrocystin/polyductin complex (FPC), is a 445-kDa protein encoded by a 67-exon transcript that spans >500 kb of genomic DNA. In the current study, we observed multiple alternatively spliced Pkhd1 transcripts that varied in size and exon composition in embryonic mouse kidney, liver, and placenta samples, as well as among adult mouse pancreas, brain, heart, lung, testes, liver, and kidney. Using reverse transcription PCR and RNASeq, we identified 22 novel Pkhd1 kidney transcripts with unique exon junctions. Various mechanisms of alternative splicing were observed, including exon skipping, use of alternate acceptor/donor splice sites, and inclusion of novel exons. Bioinformatic analyses identified, and exon-trapping minigene experiments validated, consensus binding sites for serine/arginine-rich proteins that modulate alternative splicing. Using site-directed mutagenesis, we examined the functional importance of selected splice enhancers. In addition, we demonstrated that many of the novel transcripts were polysome bound, thus likely translated. Finally, we determined that the human PKHD1 R760H missense variant alters a splice enhancer motif that disrupts exon splicing in vitro and is predicted to truncate the protein. Taken together, these data provide evidence of the complex transcriptional regulation of Pkhd1/PKHD1 and identified motifs that regulate its splicing. Our studies indicate that Pkhd1/PKHD1 transcription is modulated, in part by intragenic factors, suggesting that aberrant PKHD1 splicing represents an unappreciated pathogenic mechanism in ARPKD. Key messages: Multiple mRNA transcripts are generated for Pkhd1 in renal tissues Pkhd1 transcription is modulated by standard splice elements and effectors Mutations in splice motifs may alter splicing to generate nonfunctional peptides.
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Affiliation(s)
- Ravindra Boddu
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chaozhe Yang
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | - Amber K. O’Connor
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | | | - Braden Boone
- Hudson Alpha Institute, Huntsville, AL 35806, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Miguel Garcia-Gonzalez
- Complexo Hospitalario de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Peter Igarashi
- Department of Medicine, University of Texas Southwestern School of Medicine, Dallas, TX 75235, USA
| | - Luiz F. Onuchic
- Department of Medicine, University of Sao Paulo, Sao Paulo, Brazil 01246-903
| | - Gregory G. Germino
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lisa M. Guay-Woodford
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
- Children’s National Medical Center, 6th Floor Main Hospital, Center 6, 111 Michigan Ave NW, Washington, DC 20010, USA
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49
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Gonzalez-Paredes FJ, Ramos-Trujillo E, Claverie-Martin F. Defective pre-mRNA splicing in PKD1 due to presumed missense and synonymous mutations causing autosomal dominant polycystic disease. Gene 2014; 546:243-9. [DOI: 10.1016/j.gene.2014.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 05/21/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
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50
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Damineni S, Rao VR, Kumar S, Ravuri RR, Kagitha S, Dunna NR, Digumarthi R, Satti V. Germline mutations of TP53 gene in breast cancer. Tumour Biol 2014; 35:9219-27. [PMID: 24929325 DOI: 10.1007/s13277-014-2176-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/02/2014] [Indexed: 11/30/2022] Open
Abstract
Germline alterations of the TP53 gene encoding the p53 protein have been observed in the majority of families with the Li-Fraumeni syndrome, a rare dominantly inherited disorder with breast cancer. Genomic DNA samples of 182 breast cancer cases and 186 controls were sequenced for TP53 mutations in the exon 5-9 and intervening introns 5, 7-9. Direct sequencing was done using Applied Biosystem 3730 DNA analyzer. In the present study, we observed nine mutations in the sequenced region, of which five were novel. Hardy-Weinberg equilibrium (HWE) was done for all the mutations; C14181T, T14201G, and G13203A have shown deviation from HWE. High linkage disequilibrium (LD) was observed between C14181T (rs129547788) and T14201G (rs12951053) (r (2) = 0.98.3; D' = 1.00), whereas other observed mutations do not show strong LD with any of the other mutations. None of the intronic mutations has shown significant association with the breast cancer, two exonic mutations G13203A (rs28934578) and A14572G are significantly (P = 0.04, P = 0.007) associated with breast cancer. Germline mutations observed in DNA-binding domain of the gene showed significant association with breast cancer. This study reports five novel germline mutations in the TP53 gene out of which one mutation may confer significant risk to the breast cancer. Mutations in DNA-binding domain of TP53 gene may play role in the early onset and prognosis of breast cancer. The population-based studies of germline mutations in DNA-binding domain of TP53 gene helps in identification of individuals and families who are at risk of developing cancers.
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Affiliation(s)
- Surekha Damineni
- Department of Genetics, Osmania University, Hyderabad, 500007, India,
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