1
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Bao N, Wang Z, Fu J, Dong H, Jin Y. RNA structure in alternative splicing regulation: from mechanism to therapy. Acta Biochim Biophys Sin (Shanghai) 2024. [PMID: 39034824 DOI: 10.3724/abbs.2024119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024] Open
Abstract
Alternative splicing is a highly intricate process that plays a crucial role in post-transcriptional regulation and significantly expands the functional proteome of a limited number of coding genes in eukaryotes. Its regulation is multifactorial, with RNA structure exerting a significant impact. Aberrant RNA conformations lead to dysregulation of splicing patterns, which directly affects the manifestation of disease symptoms. In this review, the molecular mechanisms of RNA secondary structure-mediated splicing regulation are summarized, with a focus on the complex interplay between aberrant RNA conformations and disease phenotypes resulted from splicing defects. This study also explores additional factors that reshape structural conformations, enriching our understanding of the mechanistic network underlying structure-mediated splicing regulation. In addition, an emphasis has been placed on the clinical role of targeting aberrant splicing corrections in human diseases. The principal mechanisms of action behind this phenomenon are described, followed by a discussion of prospective development strategies and pertinent challenges.
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2
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Johnson KC, Kilikevicius A, Hofman C, Hu J, Liu Y, Aguilar S, Graswich J, Han Y, Wang T, Westcott JM, Brekken RA, Peng L, Karagkounis G, Corey DR. Nuclear localization of Argonaute 2 is affected by cell density and may relieve repression by microRNAs. Nucleic Acids Res 2024; 52:1930-1952. [PMID: 38109320 PMCID: PMC10899759 DOI: 10.1093/nar/gkad1155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/20/2023] Open
Abstract
Argonaute protein is associated with post-transcriptional control of cytoplasmic gene expression through miRNA-induced silencing complexes (miRISC). Specific cellular and environmental conditions can trigger AGO protein to accumulate in the nucleus. Localization of AGO is central to understanding miRNA action, yet the consequences of AGO being in the nucleus are undefined. We show nuclear enrichment of AGO2 in HCT116 cells grown in two-dimensional culture to high density, HCT116 cells grown in three-dimensional tumor spheroid culture, and human colon tumors. The shift in localization of AGO2 from cytoplasm to nucleus de-represses cytoplasmic AGO2-eCLIP targets that were candidates for canonical regulation by miRISC. Constitutive nuclear localization of AGO2 using an engineered nuclear localization signal increases cell migration. Critical RNAi factors also affect the localization of AGO2. Knocking out an enzyme essential for miRNA biogenesis, DROSHA, depletes mature miRNAs and restricts AGO2 localization to the cytoplasm, while knocking out the miRISC scaffolding protein, TNRC6, results in nuclear localization of AGO2. These data suggest that AGO2 localization and miRNA activity can be regulated depending on environmental conditions, expression of mature miRNAs, and expression of miRISC cofactors. Localization and expression of core miRISC protein machinery should be considered when investigating the roles of miRNAs.
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Affiliation(s)
- Krystal C Johnson
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Audrius Kilikevicius
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Cristina Hofman
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Jiaxin Hu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Yang Liu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Selina Aguilar
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Jon Graswich
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
| | - Yi Han
- UT Southwestern Medical Center, Peter O'Donnell Jr. School of Public Health, Dallas, TX 75235, USA
| | - Tao Wang
- UT Southwestern Medical Center, Peter O'Donnell Jr. School of Public Health, Dallas, TX 75235, USA
| | - Jill M Westcott
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235, USA
| | - Rolf A Brekken
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235, USA
| | - Lan Peng
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Pathology, Dallas, TX 75235, USA
| | - Georgios Karagkounis
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235, USA
- Memorial Sloan Kettering Cancer Center, New York, NY 10022, USA
| | - David R Corey
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235, USA
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3
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Zhang F, Pei S, Xiao M. Identification of functional genes in liver fibrosis based on bioinformatics analysis of a lncRNA-mediated ceRNA network. BMC Med Genomics 2024; 17:56. [PMID: 38378545 PMCID: PMC10877760 DOI: 10.1186/s12920-024-01813-x] [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: 06/07/2023] [Accepted: 01/20/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND Liver fibrosis is a major global healths problem; nevertheless, its molecular mechanism are not completely clear. This study aimed to build a lncRNA-miRNA-mRNA network, identify potentially related lncRNAs, and explore the pathogenesis of liver fibrosis. MATERIALS AND METHODS We used the Gene Expression Omnibus databases and bioinformatics analysis to identify differentially expressed genes (DEGs) between liver fibrosis and normal tissues. The ceRNA network was constructed according to the interactions between DElncRNA, miRNA, and DEmRNA. Then, these DEGs were identified using functional enrichment analysis, and a protein-protein interaction (PPI) network was established. The critical lncRNAs were verified using the quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS The ceRNA network was composed of three lncRNAs, five miRNAs, and 93 mRNAs. Gene Ontology functional enrichment analysis revealed significant enhancement in cell components, molecular function, and biological process. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed pathways associated with transcriptional misregulation in cancer, including the Rap1 signaling pathway, proteoglycans in cancer, mineral absorption, HTLV-l infection, and central carbon metabolism in cancer. According to the PPI network and the GSE84044 database, seven hub genes associated with liver fibrosis were identified. In addition, qRT-PCR revealed that lncRNA AC100861 (lncRNA TNFRSF10A-DT) was explicitly decreased in liver fibrosis tissues and activated hepatic stellate cells. CONCLUSIONS In summary, this study preliminarily found that lncRNA TNFRSF10A-DT may be a biomarker for the diagnosis and outcome of liver fibrosis. We uncovered a novel lncRNA-mediated ceRNA regulatory mechanism in the pathogenesis of liver fibrosis.
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Affiliation(s)
- Feng Zhang
- Department of Cardiovascular Medicine, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China
| | - Siya Pei
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China
- Department of Infection Diseases, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China
| | - Meifang Xiao
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China.
- Department of Health Management Center, Xiangya Hospital, Central South University, Hunan, Changsha, 410008, People's Republic of China.
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4
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Hofman CR, Corey DR. Targeting RNA with synthetic oligonucleotides: Clinical success invites new challenges. Cell Chem Biol 2024; 31:125-138. [PMID: 37804835 PMCID: PMC10841528 DOI: 10.1016/j.chembiol.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/27/2023] [Accepted: 09/15/2023] [Indexed: 10/09/2023]
Abstract
Synthetic antisense oligonucleotides (ASOs) and duplex RNAs (dsRNAs) are an increasingly successful strategy for drug development. After a slow start, the pace of success has accelerated since the approval of Spinraza (nusinersen) in 2016 with several drug approvals. These accomplishments have been achieved even though oligonucleotides are large, negatively charged, and have little resemblance to traditional small-molecule drugs-a remarkable achievement of basic and applied science. The goal of this review is to summarize the foundation underlying recent progress and describe ongoing research programs that may increase the scope and impact of oligonucleotide therapeutics.
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Affiliation(s)
- Cristina R Hofman
- The Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - David R Corey
- The Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA.
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5
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Guidi R, Wedeles C, Xu D, Kolmus K, Headland SE, Teng G, Guillory J, Zeng YJ, Cheung TK, Chaudhuri S, Modrusan Z, Liang Y, Horswell S, Haley B, Rutz S, Rose C, Franke Y, Kirkpatrick DS, Hackney JA, Wilson MS. Argonaute3-SF3B3 complex controls pre-mRNA splicing to restrain type 2 immunity. Cell Rep 2023; 42:113515. [PMID: 38096048 DOI: 10.1016/j.celrep.2023.113515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 08/28/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Argonaute (AGO) proteins execute microRNA (miRNA)-mediated gene silencing. However, it is unclear whether all 4 mammalian AGO proteins (AGO1, AGO2, AGO3, and AGO4) are required for miRNA activity. We generate Ago1, Ago3, and Ago4-deficient mice (Ago134Δ) and find AGO1/3/4 to be redundant for miRNA biogenesis, homeostasis, or function, a role that is carried out by AGO2. Instead, AGO1/3/4 regulate the expansion of type 2 immunity via precursor mRNA splicing in CD4+ T helper (Th) lymphocytes. Gain- and loss-of-function experiments demonstrate that nuclear AGO3 interacts directly with SF3B3, a component of the U2 spliceosome complex, to aid global mRNA splicing, and in particular the isoforms of the gene Nisch, resulting in a dysregulated Nisch isoform ratio. This work uncouples AGO1, AGO3, and AGO4 from miRNA-mediated RNA interference, identifies an AGO3:SF3B3 complex in the nucleus, and reveals a mechanism by which AGO proteins regulate inflammatory diseases.
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Affiliation(s)
- Riccardo Guidi
- Immunology Discovery, Genentech, South San Francisco, CA 94080, USA
| | | | - Daqi Xu
- Immunology Discovery, Genentech, South San Francisco, CA 94080, USA
| | - Krzysztof Kolmus
- OMNI Bioinformatics, Genentech, South San Francisco, CA 94080, USA
| | - Sarah E Headland
- Immunology Discovery, Genentech, South San Francisco, CA 94080, USA
| | - Grace Teng
- Immunology Discovery, Genentech, South San Francisco, CA 94080, USA
| | - Joseph Guillory
- Next Generation Sequencing (NGS), Genentech, South San Francisco, CA 94080, USA
| | - Yi Jimmy Zeng
- Microchemistry, Proteomics and Lipidomics, Genentech, South San Francisco, CA 94080, USA
| | - Tommy K Cheung
- Microchemistry, Proteomics and Lipidomics, Genentech, South San Francisco, CA 94080, USA
| | - Subhra Chaudhuri
- Next Generation Sequencing (NGS), Genentech, South San Francisco, CA 94080, USA
| | - Zora Modrusan
- Next Generation Sequencing (NGS), Genentech, South San Francisco, CA 94080, USA
| | - Yuxin Liang
- Next Generation Sequencing (NGS), Genentech, South San Francisco, CA 94080, USA
| | - Stuart Horswell
- Bioinformatic and Biostatistics, The Francis Crick Institute, London, UK
| | - Benjamin Haley
- Molecular Biology, Genentech, South San Francisco, CA 94080, USA
| | - Sascha Rutz
- Cancer Immunology, Genentech, South San Francisco, CA 94080, USA
| | - Christopher Rose
- Microchemistry, Proteomics and Lipidomics, Genentech, South San Francisco, CA 94080, USA
| | - Yvonne Franke
- Protein Sciences, Genentech, South San Francisco, CA 94080, USA
| | - Donald S Kirkpatrick
- Microchemistry, Proteomics and Lipidomics, Genentech, South San Francisco, CA 94080, USA
| | - Jason A Hackney
- OMNI Bioinformatics, Genentech, South San Francisco, CA 94080, USA
| | - Mark S Wilson
- Immunology Discovery, Genentech, South San Francisco, CA 94080, USA.
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6
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Zhai R, Ruan K, Perez GF, Kubat M, Liu J, Hofacker I, Wuchty S. MicroRNA-Mediated Obstruction of Stem-loop Alternative Splicing (MIMOSAS): a global mechanism for the regulation of alternative splicing. RESEARCH SQUARE 2023:rs.3.rs-2977025. [PMID: 37546804 PMCID: PMC10402249 DOI: 10.21203/rs.3.rs-2977025/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
While RNA secondary structures are critical to regulate alternative splicing of long-range pre-mRNA, the factors that modulate RNA structure and interfere with the recognition of the splice sites are largely unknown. Previously, we identified a small, non-coding microRNA that sufficiently affects stable stem structure formation of Nmnat pre-mRNA to regulate the outcomes of alternative splicing. However, the fundamental question remains whether such microRNA-mediated interference with RNA secondary structures is a global molecular mechanism for regulating mRNA splicing. We designed and refined a bioinformatic pipeline to predict candidate microRNAs that potentially interfere with pre-mRNA stem-loop structures, and experimentally verified splicing predictions of three different long-range pre-mRNAs in the Drosophila model system. Specifically, we observed that microRNAs can either disrupt or stabilize stem-loop structures to influence splicing outcomes. Our study suggests that MicroRNA-Mediated Obstruction of Stem-loop Alternative Splicing (MIMOSAS) is a novel regulatory mechanism for the transcriptome-wide regulation of alternative splicing, increases the repertoire of microRNA function and further indicates cellular complexity of post-transcriptional regulation.
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Affiliation(s)
| | - Kai Ruan
- University of Miami, Miller School of Medicine
| | | | | | - Jiaqi Liu
- University of Miami Miller School of Medicine
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7
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Johnson KC, Kilikevicius A, Hofman C, Hu J, Liu Y, Aguilar S, Graswich J, Han Y, Wang T, Westcott JM, Brekken RA, Peng L, Karagkounis G, Corey DR. Nuclear Localization of Argonaute is affected by Cell Density and May Relieve Repression by microRNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.07.548119. [PMID: 37461596 PMCID: PMC10350042 DOI: 10.1101/2023.07.07.548119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Argonaute protein is associated with post-transcriptional control of cytoplasmic gene expression through miRNA-induced silencing complexes (miRISC). Specific cellular and environmental conditions can trigger AGO protein to accumulate in the nucleus. Localization of AGO is central to understanding miRNA action, yet the consequences of AGO being in the nucleus are undefined. We show nuclear enrichment of AGO2 in HCT116 cells grown in two-dimensional culture to high density, HCT116 cells grown in three-dimensional tumor spheroid culture, and human colon tumors. The shift in localization of AGO2 from cytoplasm to nucleus de-represses cytoplasmic AGO2-eCLIP targets that were candidates for canonical regulation by miRISC. Constitutive nuclear localization of AGO2 using an engineered nuclear localization signal increases cell migration. Critical RNAi factors also affect the localization of AGO2. Knocking out an enzyme essential for miRNA biogenesis, DROSHA, depletes mature miRNAs and restricts AGO2 localization to the cytoplasm, while knocking out the miRISC scaffolding protein, TNRC6, results in nuclear localization of AGO2. These data suggest that AGO2 localization and miRNA activity can be regulated depending on environmental conditions, expression of mature miRNAs, and expression of miRISC cofactors. Localization and expression of core miRISC protein machinery should be considered when investigating the roles of miRNAs.
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Affiliation(s)
- Krystal C Johnson
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Audrius Kilikevicius
- current address, Eli Lilly, Lilly Cambridge Innovation Center, Cambridge, MA 02142
| | - Cristina Hofman
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Jiaxin Hu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Yang Liu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Selina Aguilar
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Jon Graswich
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
| | - Yi Han
- UT Southwestern Medical Center, Quantitative Biomedical Research Center, Department of Population and Data Sciences, Dallas, TX 75235
| | - Tao Wang
- UT Southwestern Medical Center, Quantitative Biomedical Research Center, Department of Population and Data Sciences, Dallas, TX 75235
| | - Jill M Westcott
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235
| | - Rolf A Brekken
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235
| | - Lan Peng
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Pathology, Dallas, TX 75235
| | - Georgios Karagkounis
- UT Southwestern Medical Center, Harold C. Simmons Comprehensive Cancer Center, Department of Surgery, Dallas, TX 75235
| | - David R Corey
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, TX 75235
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8
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Ruan K, Perez GF, Liu J, Kubat M, Hofacker I, Wuchty S, Zhai RG. MicroRNA-Mediated Obstruction of Stem-loop Alternative Splicing (MIMOSAS): a global mechanism for the regulation of alternative splicing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.14.536877. [PMID: 37425843 PMCID: PMC10327045 DOI: 10.1101/2023.04.14.536877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
While RNA secondary structures are critical to regulate alternative splicing of long-range pre-mRNA, the factors that modulate RNA structure and interfere with the recognition of the splice sites are largely unknown. Previously, we identified a small, non-coding microRNA that sufficiently affects stable stem structure formation of Nmnat pre-mRNA to regulate the outcomes of alternative splicing. However, the fundamental question remains whether such microRNA-mediated interference with RNA secondary structures is a global molecular mechanism for regulating mRNA splicing. We designed and refined a bioinformatic pipeline to predict candidate microRNAs that potentially interfere with pre-mRNA stem-loop structures, and experimentally verified splicing predictions of three different long-range pre-mRNAs in the Drosophila model system. Specifically, we observed that microRNAs can either disrupt or stabilize stem-loop structures to influence splicing outcomes. Our study suggests that MicroRNA-Mediated Obstruction of Stem-loop Alternative Splicing (MIMOSAS) is a novel regulatory mechanism for the transcriptome-wide regulation of alternative splicing, increases the repertoire of microRNA function and further indicates cellular complexity of post-transcriptional regulation. One-Sentence Summary MicroRNA-Mediated Obstruction of Stem-loop Alternative Splicing (MIMOSAS) is a novel regulatory mechanism for the transcriptome-wide regulation of alternative splicing.
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9
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Johnson KC, Corey DR. RNAi in cell nuclei: potential for a new layer of biological regulation and a new strategy for therapeutic discovery. RNA (NEW YORK, N.Y.) 2023; 29:415-422. [PMID: 36657971 PMCID: PMC10019369 DOI: 10.1261/rna.079500.122] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
RNA interference is almost always associated with post-transcriptional silencing in the cytoplasm. MicroRNAs (miRNAs) and critical RNAi protein factors like argonaute (AGO) and trinucleotide repeat binding containing 6 protein (TNRC6), however, are also found in cell nuclei, suggesting that nuclear miRNAs may be targets for gene regulation. Designed small duplex RNAs (dsRNAs) can modulate nuclear processes such as transcription and splicing, suggesting that they can also provide leads for therapeutic discovery. The goal of this Perspective is to provide the background on nuclear RNAi necessary to guide discussions on whether nuclear RNAi can play a role in therapeutic development programs.
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Affiliation(s)
- Krystal C Johnson
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - David R Corey
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
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10
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Laitinen P, Väänänen MA, Kolari IL, Mäkinen PI, Kaikkonen MU, Weinberg MS, Morris KV, Korhonen P, Malm T, Ylä-Herttuala S, Roberts TC, Turunen MP, Turunen TA. Nuclear microRNA-466c regulates Vegfa expression in response to hypoxia. PLoS One 2022; 17:e0265948. [PMID: 35358280 PMCID: PMC8975276 DOI: 10.1371/journal.pone.0265948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 03/10/2022] [Indexed: 11/18/2022] Open
Abstract
MicroRNAs are well characterized in their role in silencing gene expression by targeting 3´-UTR of mRNAs in cytoplasm. However, recent studies have shown that miRNAs have a role in the regulation of genes in the nucleus, where they are abundantly located. We show here that in mouse endothelial cell line (C166), nuclear microRNA miR-466c participates in the regulation of vascular endothelial growth factor a (Vegfa) gene expression in hypoxia. Upregulation of Vegfa expression in response to hypoxia was significantly compromised after removal of miR-466c with CRISPR-Cas9 genomic deletion. We identified a promoter-associated long non-coding RNA on mouse Vegfa promoter and show that miR-466c directly binds to this transcript to modulate Vegfa expression. Collectively, these observations suggest that miR-466c regulates Vegfa gene transcription in the nucleus by targeting the promoter, and expands on our understanding of the role of miRNAs well beyond their canonical role.
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Affiliation(s)
- Pia Laitinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- RNatives Oy, Kuopio, Finland
| | - Mari-Anna Väänänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Ida-Liisa Kolari
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Petri I. Mäkinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Minna U. Kaikkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Marc S. Weinberg
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, University of the Witwaterstrand, Witwaterstrand, South Africa
| | - Kevin V. Morris
- Center for Gene Therapy, City of Hope–Beckman Research Institute at the City of Hope, Duarte, California, United States of America
- Menzies Health Institute Queensland, School of Medical Science Griffith University, Gold Coast Campus, Queensland, Australia
| | - Paula Korhonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Heart Center and Gene Therapy Unit, Kuopio University Hospital, Kuopio, Finland
| | - Thomas C. Roberts
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- MDUK Oxford Neuromuscular Centre, Oxford, United Kingdom
| | - Mikko P. Turunen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- RNatives Oy, Kuopio, Finland
- * E-mail:
| | - Tiia A. Turunen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- RNatives Oy, Kuopio, Finland
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11
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Nazer E, Gómez Acuña L, Kornblihtt AR. Seeking the truth behind the myth: Argonaute tales from "nuclearland". Mol Cell 2021; 82:503-513. [PMID: 34856122 DOI: 10.1016/j.molcel.2021.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 12/19/2022]
Abstract
Argonaute proteins have been traditionally characterized as a highly evolutionary conserved family engaged in post-transcriptional gene silencing pathways. The Argonaute family is mainly grouped into the AGO and PIWI clades. The canonical role of Argonaute proteins relies on their ability to bind small-RNAs that recognize complementary sequences on target mRNAs to induce either mRNA degradation or translational repression. However, there is an increasing amount of evidence supporting that Argonaute proteins also exert multiple nuclear functions that subsequently regulate gene expression. In this line, genome-wide studies showed that members from the AGO clade regulate transcription, 3D chromatin organization, and splicing of active loci located within euchromatin. Here, we discuss recent work based on high-throughput technologies that have significantly contributed to shed light on the multivariate nuclear functions of AGO proteins in different model organisms. We also analyze data supporting that AGO proteins are able to execute these nuclear functions independently from small RNA pathways. Finally, we integrate these mechanistic insights with recent reports highlighting the clinical importance of AGO in breast and prostate cancer development.
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Affiliation(s)
- Ezequiel Nazer
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina.
| | - Luciana Gómez Acuña
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alberto R Kornblihtt
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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12
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Chu Y, Yokota S, Liu J, Kilikevicius A, Johnson KC, Corey DR. Argonaute binding within human nuclear RNA and its impact on alternative splicing. RNA (NEW YORK, N.Y.) 2021; 27:991-1003. [PMID: 34108230 PMCID: PMC8370746 DOI: 10.1261/rna.078707.121] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/04/2021] [Indexed: 05/03/2023]
Abstract
Mammalian RNA interference (RNAi) is often linked to the regulation of gene expression in the cytoplasm. Synthetic RNAs, however, can also act through the RNAi pathway to regulate transcription and splicing. While nuclear regulation by synthetic RNAs can be robust, a critical unanswered question is whether endogenous functions for nuclear RNAi exist in mammalian cells. Using enhanced crosslinking immunoprecipitation (eCLIP) in combination with RNA sequencing (RNA-seq) and multiple AGO knockout cell lines, we mapped AGO2 protein binding sites within nuclear RNA. The strongest AGO2 binding sites were mapped to micro RNAs (miRNAs). The most abundant miRNAs were distributed similarly between the cytoplasm and nucleus, providing no evidence for mechanisms that facilitate localization of miRNAs in one compartment versus the other. Beyond miRNAs, most statistically significant AGO2 binding was within introns. Splicing changes were confirmed by RT-PCR and recapitulated by synthetic miRNA mimics complementary to the sites of AGO2 binding. These data support the hypothesis that miRNAs can control gene splicing. While nuclear RNAi proteins have the potential to be natural regulatory mechanisms, careful study will be necessary to identify critical RNA drivers of normal physiology and disease.
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Affiliation(s)
- Yongjun Chu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Shinnichi Yokota
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Jing Liu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Audrius Kilikevicius
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Krystal C Johnson
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - David R Corey
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
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13
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Johnson ST, Chu Y, Liu J, Corey DR. Impact of scaffolding protein TNRC6 paralogs on gene expression and splicing. RNA (NEW YORK, N.Y.) 2021; 27:1004-1016. [PMID: 34108231 PMCID: PMC8370741 DOI: 10.1261/rna.078709.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/04/2021] [Indexed: 05/11/2023]
Abstract
TNRC6 is a scaffolding protein that bridges interactions between small RNAs, argonaute (AGO) protein, and effector proteins to control gene expression. There are three paralogs in mammalian cells, TNRC6A, TNRC6B, and TNRC6C These paralogs have ∼40% amino acid sequence identity and the extent of their unique or redundant functions is unclear. Here, we use knockout cell lines, enhanced crosslinking immunoprecipitation (eCLIP), and high-throughput RNA sequencing (RNA-seq) to explore the roles of TNRC6 paralogs in RNA-mediated control of gene expression. We find that the paralogs are largely functionally redundant and changes in levels of gene expression are well-correlated with those observed in AGO knockout cell lines. Splicing changes observed in AGO knockout cell lines are also observed in TNRC6 knockout cells. These data further define the roles of the TNRC6 isoforms as part of the RNA interference (RNAi) machinery.
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Affiliation(s)
- Samantha T Johnson
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Yongjun Chu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - Jing Liu
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
| | - David R Corey
- UT Southwestern Medical Center, Departments of Pharmacology and Biochemistry, Dallas, Texas 75205, USA
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14
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Rothzerg E, Ho XD, Xu J, Wood D, Märtson A, Kõks S. Upregulation of 15 Antisense Long Non-Coding RNAs in Osteosarcoma. Genes (Basel) 2021; 12:genes12081132. [PMID: 34440306 PMCID: PMC8394133 DOI: 10.3390/genes12081132] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 12/14/2022] Open
Abstract
The human genome encodes thousands of natural antisense long noncoding RNAs (lncRNAs); they play the essential role in regulation of gene expression at multiple levels, including replication, transcription and translation. Dysregulation of antisense lncRNAs plays indispensable roles in numerous biological progress, such as tumour progression, metastasis and resistance to therapeutic agents. To date, there have been several studies analysing antisense lncRNAs expression profiles in cancer, but not enough to highlight the complexity of the disease. In this study, we investigated the expression patterns of antisense lncRNAs from osteosarcoma and healthy bone samples (24 tumour-16 bone samples) using RNA sequencing. We identified 15 antisense lncRNAs (RUSC1-AS1, TBX2-AS1, PTOV1-AS1, UBE2D3-AS1, ERCC8-AS1, ZMIZ1-AS1, RNF144A-AS1, RDH10-AS1, TRG-AS1, GSN-AS1, HMGA2-AS1, ZNF528-AS1, OTUD6B-AS1, COX10-AS1 and SLC16A1-AS1) that were upregulated in tumour samples compared to bone sample controls. Further, we performed real-time polymerase chain reaction (RT-qPCR) to validate the expressions of the antisense lncRNAs in 8 different osteosarcoma cell lines (SaOS-2, G-292, HOS, U2-OS, 143B, SJSA-1, MG-63, and MNNG/HOS) compared to hFOB (human osteoblast cell line). These differentially expressed IncRNAs can be considered biomarkers and potential therapeutic targets for osteosarcoma.
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Affiliation(s)
- Emel Rothzerg
- School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia; (E.R.); (J.X.); (D.W.)
- Perron Institute for Neurological and Translational Science, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Xuan Dung Ho
- Department of Oncology, College of Medicine and Pharmacy, Hue University, Hue 53000, Vietnam;
| | - Jiake Xu
- School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia; (E.R.); (J.X.); (D.W.)
| | - David Wood
- School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia; (E.R.); (J.X.); (D.W.)
| | - Aare Märtson
- Department of Traumatology and Orthopaedics, University of Tartu, Tartu University Hospital, 50411 Tartu, Estonia;
| | - Sulev Kõks
- Perron Institute for Neurological and Translational Science, QEII Medical Centre, Nedlands, WA 6009, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA 6150, Australia
- Correspondence: ; Tel.: +61-(0)-8-6457-0313
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15
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MicroRNA 195-5p Targets Foxo3 Promoter Region to Regulate Its Expression in Granulosa Cells. Int J Mol Sci 2021; 22:ijms22136721. [PMID: 34201585 PMCID: PMC8267755 DOI: 10.3390/ijms22136721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/24/2022] Open
Abstract
Forkhead box O3 (Foxo3) is a member of the FOXO subfamily within the forkhead box (FOX) family, which has been shown to be essential for ovarian follicular development and maturation. Previous studies have shown the abundant expression of miR-195-5p in the nuclei of porcine granulosa cells (GCs), suggesting its potential role during ovarian follicle growth. In this study, a conditional immortalized porcine granulosa cell (CIPGC) line was used to determine whether the expression of Foxo3 could be regulated by the nuclear-enriched miR-195-5p. Through silico target prediction, we identified a potential binding site of miR-195-5p within the Foxo3 promoter. The over-expression of miR-195-5p increased Foxo3 expression at both mRNA and protein levels, while the knockdown of miR-195-5p decreased the expression of Foxo3. Furthermore, driven by the Foxo3 promoter, luciferase reporter activity was increased in response to miR-195-5p, while the mutation of the miR-195-5p binding site in the promoter region abolished this effect. In addition, the siRNA knockdown of Argonaute (AGO) 2, but not AGO1, significantly decreased Foxo3 transcript level. However, miR-195-5p failed to upregulate Foxo3 expression when AGO2 was knocked down. Moreover, chromatin immunoprecipitation (CHIP) assay showed that anti-AGO2 antibody pulled down both AGO2 and the Foxo3 promoter sequence, suggesting that AGO2 may be required for miR-195-5p to regulate Foxo3 expression in the nucleus. Additionally, Foxo3 expression was significantly increased by valproic acid (VPA), the inhibitor of deacetylase, as well as by methyltransferase inhibitor BIX-01294, indicating the involvement of histone modification. These effects were further enhanced in the presence of miR-195-5p and were decreased when miR-195-5p was knocked down. Overall, our results suggest that nuclear-enriched miR-195-5p regulates Foxo3 expression, which may be associated with AGO2 recruitment, as well as histone demethylation and acetylation in ovarian granulosa cells.
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16
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Gong M, Zhang X, Wang Y, Mao G, Ou Y, Wei C, Hu X, Xiang S. DDX21 interacts with nuclear AGO2 and regulates the alternative splicing of SMN2. Biosci Biotechnol Biochem 2021; 85:272-279. [PMID: 33604619 DOI: 10.1093/bbb/zbaa029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/17/2020] [Indexed: 01/30/2023]
Abstract
AGO2 is the only member of mammalian Ago protein family that possesses the catalytic activity and plays a central role in gene silencing. Recently researches reported that multiple gene silencing factors, including AGO2, function in the nuclei. The molecular mechanisms of the gene silencing factors functioning in nuclei are conducive to comprehend the roles of gene silencing in pretranslational regulation of gene expression. Here, we report that AGO2 interacts with DDX21 indirectly in an RNA-dependent manner by Co-IP and GST-Pulldown assays and the 2 proteins present nuclei foci in the immunofluorescence experiments. We found that DDX21 up-regulated the protein level of AGO2 and participated in target gene, SNM2, alternative splicing involved in AGO2 by the indirect interaction with AGO2, which produced different transcripts of SMN2 in discrepant expression level. This study laid important experiment foundation for the further analysis of the nuclear functions of gene silencing components.
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Affiliation(s)
- Mengting Gong
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China.,College of Physical Education, Hunan University of Finance and Economics, Changsha, China
| | - Xi Zhang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yaru Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Guiyan Mao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yangqi Ou
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Chenxi Wei
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiang Hu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Shuanglin Xiang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
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17
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Odame E, Chen Y, Zheng S, Dai D, Kyei B, Zhan S, Cao J, Guo J, Zhong T, Wang L, Li L, Zhang H. Enhancer RNAs: transcriptional regulators and workmates of NamiRNAs in myogenesis. Cell Mol Biol Lett 2021; 26:4. [PMID: 33568070 PMCID: PMC7877072 DOI: 10.1186/s11658-021-00248-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/02/2021] [Indexed: 02/08/2023] Open
Abstract
miRNAs are well known to be gene repressors. A newly identified class of miRNAs termed nuclear activating miRNAs (NamiRNAs), transcribed from miRNA loci that exhibit enhancer features, promote gene expression via binding to the promoter and enhancer marker regions of the target genes. Meanwhile, activated enhancers produce endogenous non-coding RNAs (named enhancer RNAs, eRNAs) to activate gene expression. During chromatin looping, transcribed eRNAs interact with NamiRNAs through enhancer-promoter interaction to perform similar functions. Here, we review the functional differences and similarities between eRNAs and NamiRNAs in myogenesis and disease. We also propose models demonstrating their mutual mechanism and function. We conclude that eRNAs are active molecules, transcriptional regulators, and partners of NamiRNAs, rather than mere RNAs produced during enhancer activation.
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Affiliation(s)
- Emmanuel Odame
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yuan Chen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shuailong Zheng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Dinghui Dai
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Bismark Kyei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Siyuan Zhan
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiaxue Cao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiazhong Guo
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Tao Zhong
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Linjie Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Li Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Hongping Zhang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
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18
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Liu P, Zhao L, Gu Y, Zhang M, Gao H, Meng Y. LncRNA SNHG16 promotes pulmonary fibrosis by targeting miR-455-3p to regulate the Notch2 pathway. Respir Res 2021; 22:44. [PMID: 33549106 PMCID: PMC7866661 DOI: 10.1186/s12931-021-01632-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
Background Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung diseases with a poor prognosis. Long non-coding RNAs (lncRNAs) have been reported to be involved in IPF in several studies. However, the role of lncRNA SNHG16 in IPF is largely unknown. Methods Firstly, experimental pulmonary fibrosis model was established by using bleomycin (BML). Histology and Western blotting assays were used to determine the different stages of fibrosis and expression of several fibrosis biomarkers. The expression of SNHG16 was detected by quantitative real-time polymerase chain reaction (qRT‐PCR). EdU staining and wound-healing assay were utilized to analyze proliferation and migration of lung fibroblast cells. Molecular mechanism of SNHG16 was explored by bioinformatics, dual-luciferase reporter assay, RNA immunoprecipitation assay (RIP), and qRT-PCR. Results The expression of SNHG16 was significantly up-regulated in bleomycin-(BLM) induced lung fibrosis and transforming growth factor-β (TGF-β)-induced fibroblast. Knockdown of SNHG16 could attenuate fibrogenesis. Mechanistically, SNHG16 was able to bind and regulate the expression of miR-455-3p. Moreover, SNHG16 also regulated the expression of Notch2 by targeting miR-455-3p. Finally, SNHG16 could promote fibrogenesis by regulating the expression of Notch2. Conclusion Taken together, our study demonstrated that SNHG16 promoted pulmonary fibrosis by targeting miR-455-3p to regulate the Notch2 pathway. These findings might provide a novel insight into pathologic process of lung fibrosis and may provide prevention strategies in the future.
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Affiliation(s)
- Panpan Liu
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China
| | - Lei Zhao
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China.
| | - Yuxia Gu
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China
| | - Meilan Zhang
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China
| | - Hongchang Gao
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China
| | - Yingxia Meng
- Department of Pulmonary and Critical Care Medicine, Shanghai Pudong New Area Gongli Hospital, 219 Miao Pu Road, Shanghai, 200315, China
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19
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Qadir MI, Bukhat S, Rasul S, Manzoor H, Manzoor M. RNA therapeutics: Identification of novel targets leading to drug discovery. J Cell Biochem 2019; 121:898-929. [DOI: 10.1002/jcb.29364] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022]
Affiliation(s)
- Muhammad Imran Qadir
- Institute of Molecular Biology and Biotechnology Bahauddin Zakariya University Multan Pakistan
| | - Sherien Bukhat
- Institute of Molecular Biology and Biotechnology Bahauddin Zakariya University Multan Pakistan
| | - Sumaira Rasul
- Institute of Molecular Biology and Biotechnology Bahauddin Zakariya University Multan Pakistan
| | - Hamid Manzoor
- Institute of Molecular Biology and Biotechnology Bahauddin Zakariya University Multan Pakistan
| | - Majid Manzoor
- College of Pharmaceutical Sciences Zhejiang University Hangzhou China
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20
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Park J, Zhu Y, Tao X, Brazill JM, Li C, Wuchty S, Zhai RG. MicroRNA miR-1002 Enhances NMNAT-Mediated Stress Response by Modulating Alternative Splicing. iScience 2019; 19:1048-1064. [PMID: 31522116 PMCID: PMC6745518 DOI: 10.1016/j.isci.2019.08.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 05/07/2019] [Accepted: 08/27/2019] [Indexed: 11/30/2022] Open
Abstract
Understanding endogenous regulation of stress resistance and homeostasis maintenance is critical to developing neuroprotective therapies. Nicotinamide mononucleotide adenylyltransferase (NMNAT) is a conserved essential enzyme that confers extraordinary protection and stress resistance in many neurodegenerative disease models. Drosophila Nmnat is alternatively spliced to two mRNA variants, RA and RB. RB translates to protein isoform PD with robust protective activity and is upregulated upon stress to confer enhanced neuroprotection. The mechanisms regulating the alternative splicing and stress response of NMNAT remain unclear. We have discovered a Drosophila microRNA, dme-miR-1002, which promotes the splicing of NMNAT pre-mRNA to RB by disrupting a pre-mRNA stem-loop structure. NMNAT pre-mRNA is preferentially spliced to RA in basal conditions, whereas miR-1002 enhances NMNAT PD-mediated stress protection by binding via RISC component Argonaute1 to the pre-mRNA, facilitating the splicing switch to RB. These results outline a new process for microRNAs in regulating alternative splicing and modulating stress resistance.
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Affiliation(s)
- Joun Park
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Yi Zhu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Jennifer M Brazill
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Chong Li
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Human Genetics and Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Stefan Wuchty
- Department of Computer Science, University of Miami, Coral Gables, FL 33146, USA
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Program in Human Genetics and Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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21
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Turunen TA, Roberts TC, Laitinen P, Väänänen MA, Korhonen P, Malm T, Ylä-Herttuala S, Turunen MP. Changes in nuclear and cytoplasmic microRNA distribution in response to hypoxic stress. Sci Rep 2019; 9:10332. [PMID: 31316122 PMCID: PMC6637125 DOI: 10.1038/s41598-019-46841-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 07/05/2019] [Indexed: 02/08/2023] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that have well-characterized roles in cytoplasmic gene regulation, where they act by binding to mRNA transcripts and inhibiting their translation (i.e. post-transcriptional gene silencing, PTGS). However, miRNAs have also been implicated in transcriptional gene regulation and alternative splicing, events that are restricted to the cell nucleus. Here we performed nuclear-cytoplasmic fractionation in a mouse endothelial cell line and characterized the localization of miRNAs in response to hypoxia using small RNA sequencing. A highly diverse population of abundant miRNA species was detected in the nucleus, of which the majority (56%) was found to be preferentially localized in one compartment or the other. Induction of hypoxia resulted in changes in miRNA levels in both nuclear and cytoplasmic compartments, with the majority of changes being restricted to one location and not the other. Notably, the classical hypoxamiR (miR-210-3p) was highly up-regulated in the nuclear compartment after hypoxic stimulus. These findings reveal a previously unappreciated level of molecular complexity in the physiological response occurring in ischemic tissue. Furthermore, widespread differential miRNA expression in the nucleus strongly suggests that these small RNAs are likely to perform extensive nuclear regulatory functions in the general case.
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Affiliation(s)
- Tiia A Turunen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
| | - Thomas C Roberts
- Department of Paediatrics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.,Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Pia Laitinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
| | - Mari-Anna Väänänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
| | - Paula Korhonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland.,Heart Center and Gene Therapy Unit, Kuopio University Hospital, PO Box 100, 70029 KUH, Kuopio, Finland
| | - Mikko P Turunen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland.
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22
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Shen X, Corey DR. Chemistry, mechanism and clinical status of antisense oligonucleotides and duplex RNAs. Nucleic Acids Res 2019; 46:1584-1600. [PMID: 29240946 PMCID: PMC5829639 DOI: 10.1093/nar/gkx1239] [Citation(s) in RCA: 439] [Impact Index Per Article: 87.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 11/29/2017] [Indexed: 12/12/2022] Open
Abstract
RNA plays a central role in the expression of all genes. Because any sequence within RNA can be recognized by complementary base pairing, synthetic oligonucleotides and oligonucleotide mimics offer a general strategy for controlling processes that affect disease. The two primary antisense approaches for regulating expression through recognition of cellular RNAs are single-stranded antisense oligonucleotides and duplex RNAs. This review will discuss the chemical modifications and molecular mechanisms that make synthetic nucleic acid drugs possible. Lessons learned from recent clinical trials will be summarized. Ongoing clinical trials are likely to decisively test the adequacy of our current generation of antisense nucleic acid technologies and highlight areas where more basic research is needed.
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Affiliation(s)
- Xiulong Shen
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - David R Corey
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
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23
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Bajczyk M, Bhat SS, Szewc L, Szweykowska-Kulinska Z, Jarmolowski A, Dolata J. Novel Nuclear Functions of Arabidopsis ARGONAUTE1: Beyond RNA Interference. PLANT PHYSIOLOGY 2019; 179:1030-1039. [PMID: 30606888 PMCID: PMC6393810 DOI: 10.1104/pp.18.01351] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/21/2018] [Indexed: 05/04/2023]
Abstract
Argonaute1 activity is not limited to the cytoplasm and has been found to be associated with the regulation of gene expression in the nucleus and to be tightly associated with chromatin and transcription.
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Affiliation(s)
- Mateusz Bajczyk
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Susheel Sagar Bhat
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Lukasz Szewc
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Zofia Szweykowska-Kulinska
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Artur Jarmolowski
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Jakub Dolata
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
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Sarshad AA, Juan AH, Muler AIC, Anastasakis DG, Wang X, Genzor P, Feng X, Tsai PF, Sun HW, Haase AD, Sartorelli V, Hafner M. Argonaute-miRNA Complexes Silence Target mRNAs in the Nucleus of Mammalian Stem Cells. Mol Cell 2018; 71:1040-1050.e8. [PMID: 30146314 PMCID: PMC6690358 DOI: 10.1016/j.molcel.2018.07.020] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 06/12/2018] [Accepted: 07/17/2018] [Indexed: 01/13/2023]
Abstract
In mammals, gene silencing by the RNA-induced silencing complex (RISC) is a well-understood cytoplasmic posttranscriptional gene regulatory mechanism. Here, we show that embryonic stem cells (ESCs) contain high levels of nuclear AGO proteins and that in ESCs nuclear AGO protein activity allows for the onset of differentiation. In the nucleus, AGO proteins interact with core RISC components, including the TNRC6 proteins and the CCR4-NOT deadenylase complex. In contrast to cytoplasmic miRNA-mediated gene silencing that mainly operates on cis-acting elements in mRNA 3' untranslated (UTR) sequences, in the nucleus AGO binding in the coding sequence and potentially introns also contributed to post-transcriptional gene silencing. Thus, nuclear localization of AGO proteins in specific cell types leads to a previously unappreciated expansion of the miRNA-regulated transcriptome.
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Affiliation(s)
- Aishe A Sarshad
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Aster H Juan
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Ana Iris Correa Muler
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Dimitrios G Anastasakis
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Xiantao Wang
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Pavol Genzor
- Laboratory of Biochemistry and Molecular Biology, National Institute for Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD 20892, USA
| | - Xuesong Feng
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Pei-Fang Tsai
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Hong-Wei Sun
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA
| | - Astrid D Haase
- Laboratory of Biochemistry and Molecular Biology, National Institute for Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD 20892, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA.
| | - Markus Hafner
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, 50 South Drive, Bethesda, MD 20892, USA.
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25
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Liu J, Liu Z, Corey DR. The Requirement for GW182 Scaffolding Protein Depends on Whether Argonaute Is Mediating Translation, Transcription, or Splicing. Biochemistry 2018; 57:5247-5256. [PMID: 30086238 DOI: 10.1021/acs.biochem.8b00602] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
GW182 and argonaute 2 (AGO2) are core proteins of the RNA interference complex. GW182 is a scaffolding protein that physically associates with AGO2 and bridges its interactions with other proteins. A fundamental problem in biology is how scaffolding proteins adapt or contribute to differing functional demands within cells. Here we test the necessity for human GW182 proteins (paralogs TNRC6A, TNRC6B, and TNRC6C) for several mechanisms of small duplex RNA-mediated control of gene expression, including translational silencing by miRNAs, translational silencing by siRNAs, transcriptional silencing, transcriptional activation, and splicing. We find that GW182 is required for transcriptional activation and for the activity of miRNAs but is dispensable for the regulation of splicing, transcriptional silencing, and the action of siRNAs. AGO2, by contrast, is necessary for each of these processes. Our data suggest that GW182 does not alter AGO2 to make it active. Instead, GW182 organizes protein complexes around AGO2. Sometimes this higher level of organization is necessary, and sometimes it is not. AGO2 and GW182 offer an example for how a partnership between a scaffolding protein and a functional protein can be powerful but not obligatory.
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Affiliation(s)
- Jing Liu
- Departments of Pharmacology and Biochemistry , The University of Texas Southwestern Medical Center , Dallas , Texas 75390 , United States
| | - Zhongtian Liu
- Departments of Pharmacology and Biochemistry , The University of Texas Southwestern Medical Center , Dallas , Texas 75390 , United States.,College of Animal Science and Technology , Northwest A&F University , Shaanxi , China 712100
| | - David R Corey
- Departments of Pharmacology and Biochemistry , The University of Texas Southwestern Medical Center , Dallas , Texas 75390 , United States
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26
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Hicks JA, Li L, Matsui M, Chu Y, Volkov O, Johnson KC, Corey DR. Human GW182 Paralogs Are the Central Organizers for RNA-Mediated Control of Transcription. Cell Rep 2018; 20:1543-1552. [PMID: 28813667 DOI: 10.1016/j.celrep.2017.07.058] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/10/2017] [Accepted: 07/20/2017] [Indexed: 01/21/2023] Open
Abstract
In the cytoplasm, small RNAs can control mammalian translation by regulating the stability of mRNA. In the nucleus, small RNAs can also control transcription and splicing. The mechanisms for RNA-mediated nuclear regulation are not understood and remain controversial, hindering the effective application of nuclear RNAi and investigation of its natural regulatory roles. Here, we reveal that the human GW182 paralogs TNRC6A/B/C are central organizing factors critical to RNA-mediated transcriptional activation. Mass spectrometry of purified nuclear lysates followed by experimental validation demonstrates that TNRC6A interacts with proteins involved in protein degradation, RNAi, the CCR4-NOT complex, the mediator complex, and histone-modifying complexes. Functional analysis implicates TNRC6A, NAT10, MED14, and WDR5 in RNA-mediated transcriptional activation. These findings describe protein complexes capable of bridging RNA-mediated sequence-specific recognition of noncoding RNA transcripts with the regulation of gene transcription.
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Affiliation(s)
- Jessica A Hicks
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Liande Li
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Masayuki Matsui
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Yongjun Chu
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Oleg Volkov
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Krystal C Johnson
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - David R Corey
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA.
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27
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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28
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Pitchiaya S, Heinicke LA, Park JI, Cameron EL, Walter NG. Resolving Subcellular miRNA Trafficking and Turnover at Single-Molecule Resolution. Cell Rep 2017; 19:630-642. [PMID: 28423324 PMCID: PMC5482240 DOI: 10.1016/j.celrep.2017.03.075] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/17/2017] [Accepted: 03/28/2017] [Indexed: 11/20/2022] Open
Abstract
Regulation of microRNA (miRNA) localization and stability is critical for their extensive cytoplasmic RNA silencing activity and emerging nuclear functions. Here, we have developed single-molecule fluorescence-based tools to assess the subcellular trafficking, integrity, and activity of miRNAs. We find that seed-matched RNA targets protect miRNAs against degradation and enhance their nuclear retention. While target-stabilized, functional, cytoplasmic miRNAs reside in high-molecular-weight complexes, nuclear miRNAs, as well as cytoplasmic miRNAs targeted by complementary anti-miRNAs, are sequestered stably within significantly lower-molecular-weight complexes and rendered repression incompetent. miRNA stability and activity depend on Argonaute protein abundance, whereas miRNA strand selection, unwinding, and nuclear retention depend on Argonaute identity. Taken together, our results show that miRNA degradation competes with Argonaute loading and target binding to control subcellular miRNA abundance for gene silencing surveillance. Probing single cells for miRNA activity, trafficking, and metabolism promises to facilitate screening for effective miRNA mimics and anti-miRNA drugs.
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Affiliation(s)
- Sethuramasundaram Pitchiaya
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Laurie A Heinicke
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Jun I Park
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Elizabeth L Cameron
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Nils G Walter
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
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29
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Desgagné V, Bouchard L, Guérin R. microRNAs in lipoprotein and lipid metabolism: from biological function to clinical application. Clin Chem Lab Med 2017; 55:667-686. [PMID: 27987357 DOI: 10.1515/cclm-2016-0575] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/31/2016] [Indexed: 12/21/2022]
Abstract
microRNAs (miRNAs) are short (~22 nucleotides), non-coding, single-stranded RNA molecules that regulate the expression of target genes by partial sequence-specific base-pairing to the targeted mRNA 3'UTR, blocking its translation, and promoting its degradation or its sequestration into processing bodies. miRNAs are important regulators of several physiological processes including developmental and metabolic functions, but their concentration in circulation has also been reported to be altered in many pathological conditions such as familial hypercholesterolemia, cardiovascular diseases, obesity, type 2 diabetes, and cancers. In this review, we focus on the role of miRNAs in lipoprotein and lipid metabolism, with special attention to the well-characterized miR-33a/b, and on the huge potential of miRNAs for clinical application as biomarkers and therapeutics in the context of cardiometabolic diseases.
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Affiliation(s)
| | - Luigi Bouchard
- Département de biochimie, Université de Sherbrooke, Sherbrooke, Québec
| | - Renée Guérin
- Département de biochimie, Université de Sherbrooke, Sherbrooke, Québec
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30
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Abstract
Most of the human genome encodes RNAs that do not code for proteins. These non-coding RNAs (ncRNAs) may affect normal gene expression and disease progression, making them a new class of targets for drug discovery. Because their mechanisms of action are often novel, developing drugs to target ncRNAs will involve equally novel challenges. However, many potential problems may already have been solved during the development of technologies to target mRNA. Here, we discuss the growing field of ncRNA - including microRNA, intronic RNA, repetitive RNA and long non-coding RNA - and assess the potential and challenges in their therapeutic exploitation.
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Affiliation(s)
- Masayuki Matsui
- Departments of Pharmacology and Biochemistry, UT Southwestern, Dallas, Texas 75390-9041, USA
| | - David R Corey
- Departments of Pharmacology and Biochemistry, UT Southwestern, Dallas, Texas 75390-9041, USA
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31
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Corey DR. RNA-Mediated Gene Activation: Identifying a Candidate RNA for Preclinical Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [DOI: 10.1007/978-981-10-4310-9_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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32
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Abstract
The discovery of an ever-expanding plethora of coding and non-coding RNAs with nodal and causal roles in the regulation of lung physiology and disease is reinvigorating interest in the clinical utility of the oligonucleotide therapeutic class. This is strongly supported through recent advances in nucleic acids chemistry, synthetic oligonucleotide delivery and viral gene therapy that have succeeded in bringing to market at least three nucleic acid-based drugs. As a consequence, multiple new candidates such as RNA interference modulators, antisense, and splice switching compounds are now progressing through clinical evaluation. Here, manipulation of RNA for the treatment of lung disease is explored, with emphasis on robust pharmacological evidence aligned to the five pillars of drug development: exposure to the appropriate tissue, binding to the desired molecular target, evidence of the expected mode of action, activity in the relevant patient population and commercially viable value proposition.
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33
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Catalanotto C, Cogoni C, Zardo G. MicroRNA in Control of Gene Expression: An Overview of Nuclear Functions. Int J Mol Sci 2016; 17:ijms17101712. [PMID: 27754357 PMCID: PMC5085744 DOI: 10.3390/ijms17101712] [Citation(s) in RCA: 774] [Impact Index Per Article: 96.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022] Open
Abstract
The finding that small non-coding RNAs (ncRNAs) are able to control gene expression in a sequence specific manner has had a massive impact on biology. Recent improvements in high throughput sequencing and computational prediction methods have allowed the discovery and classification of several types of ncRNAs. Based on their precursor structures, biogenesis pathways and modes of action, ncRNAs are classified as small interfering RNAs (siRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), endogenous small interfering RNAs (endo-siRNAs or esiRNAs), promoter associate RNAs (pRNAs), small nucleolar RNAs (snoRNAs) and sno-derived RNAs. Among these, miRNAs appear as important cytoplasmic regulators of gene expression. miRNAs act as post-transcriptional regulators of their messenger RNA (mRNA) targets via mRNA degradation and/or translational repression. However, it is becoming evident that miRNAs also have specific nuclear functions. Among these, the most studied and debated activity is the miRNA-guided transcriptional control of gene expression. Although available data detail quite precisely the effectors of this activity, the mechanisms by which miRNAs identify their gene targets to control transcription are still a matter of debate. Here, we focus on nuclear functions of miRNAs and on alternative mechanisms of target recognition, at the promoter lavel, by miRNAs in carrying out transcriptional gene silencing.
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Affiliation(s)
- Caterina Catalanotto
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
| | - Carlo Cogoni
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
| | - Giuseppe Zardo
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
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34
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Sperling R. The nuts and bolts of the endogenous spliceosome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27465259 DOI: 10.1002/wrna.1377] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 01/09/2023]
Abstract
The complex life of pre-mRNA from transcription to the production of mRNA that can be exported from the nucleus to the cytoplasm to encode for proteins entails intricate coordination and regulation of a network of processing events. Coordination is required between transcription and splicing and between several processing events including 5' and 3' end processing, splicing, alternative splicing and editing that are major contributors to the diversity of the human proteome, and occur within a huge and dynamic macromolecular machine-the endogenous spliceosome. Detailed mechanistic insight of the splicing reaction was gained from studies of the in vitro spliceosome assembled on a single intron. Because most pre-mRNAs are multiintronic that undergo alternative splicing, the in vivo splicing machine requires additional elements to those of the in vitro machine, to account for all these diverse functions. Information about the endogenous spliceosome is emerging from imaging studies in intact and live cells that support the cotranscriptional commitment to splicing model and provide information about splicing kinetics in vivo. Another source comes from studies of the in vivo assembled spliceosome, isolated from cell nuclei under native conditions-the supraspliceosome-that individually package pre-mRNA transcripts of different sizes and number of introns into complexes of a unique structure, indicating their universal nature. Recent years have portrayed new players affecting alternative splicing and novel connections between splicing, transcription and chromatin. The challenge ahead is to elucidate the structure and function of the endogenous spliceosome and decipher the regulation and coordination of its network of processing activities. WIREs RNA 2017, 8:e1377. doi: 10.1002/wrna.1377 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Ruth Sperling
- Department of Genetics, The Hebrew University of Jerusalem, Jerusalem, Israel
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35
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Kalantari R, Hicks JA, Li L, Gagnon KT, Sridhara V, Lemoff A, Mirzaei H, Corey DR. Stable association of RNAi machinery is conserved between the cytoplasm and nucleus of human cells. RNA (NEW YORK, N.Y.) 2016; 22:1085-98. [PMID: 27198507 PMCID: PMC4911916 DOI: 10.1261/rna.056499.116] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/25/2016] [Indexed: 05/25/2023]
Abstract
Argonaute 2 (AGO2), the catalytic engine of RNAi, is typically associated with inhibition of translation in the cytoplasm. AGO2 has also been implicated in nuclear processes including transcription and splicing. There has been little insight into AGO2's nuclear interactions or how they might differ relative to cytoplasm. Here we investigate the interactions of cytoplasmic and nuclear AGO2 using semi-quantitative mass spectrometry. Mass spectrometry often reveals long lists of candidate proteins, complicating efforts to rigorously discriminate true interacting partners from artifacts. We prioritized candidates using orthogonal analytical strategies that compare replicate mass spectra of proteins associated with Flag-tagged and endogenous AGO2. Interactions with TRNC6A, TRNC6B, TNRC6C, and AGO3 are conserved between nuclei and cytoplasm. TAR binding protein interacted stably with cytoplasmic AGO2 but not nuclear AGO2, consistent with strand loading in the cytoplasm. Our data suggest that interactions between functionally important components of RNAi machinery are conserved between the nucleus and cytoplasm but that accessory proteins differ. Orthogonal analysis of mass spectra is a powerful approach to streamlining identification of protein partners.
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Affiliation(s)
- Roya Kalantari
- Department of Pharmacology, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Jessica A Hicks
- Department of Pharmacology, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Liande Li
- Department of Pharmacology, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Keith T Gagnon
- Department of Biochemistry and Molecular Biology, Southern Illinois University, Carbondale, Illinois 62901, USA
| | - Viswanadham Sridhara
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Hamid Mirzaei
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - David R Corey
- Department of Pharmacology, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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36
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Li L, Matsui M, Corey DR. Activating frataxin expression by repeat-targeted nucleic acids. Nat Commun 2016; 7:10606. [PMID: 26842135 PMCID: PMC4742999 DOI: 10.1038/ncomms10606] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 01/04/2016] [Indexed: 12/20/2022] Open
Abstract
Friedreich's ataxia is an incurable genetic disorder caused by a mutant expansion of the trinucleotide GAA within an intronic FXN RNA. This expansion leads to reduced expression of frataxin (FXN) protein and evidence suggests that transcriptional repression is caused by an R-loop that forms between the expanded repeat RNA and complementary genomic DNA. Synthetic agents that increase levels of FXN protein might alleviate the disease. We demonstrate that introducing anti-GAA duplex RNAs or single-stranded locked nucleic acids into patient-derived cells increases FXN protein expression to levels similar to analogous wild-type cells. Our data are significant because synthetic nucleic acids that target GAA repeats can be lead compounds for restoring curative FXN levels. More broadly, our results demonstrate that interfering with R-loop formation can trigger gene activation and reveal a new strategy for upregulating gene expression.
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Affiliation(s)
- Liande Li
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, 6001 Forest Park Road, Dallas, Texas 75390-9041, USA
| | - Masayuki Matsui
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, 6001 Forest Park Road, Dallas, Texas 75390-9041, USA
| | - David R. Corey
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, 6001 Forest Park Road, Dallas, Texas 75390-9041, USA
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37
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Kalantari R, Chiang CM, Corey DR. Regulation of mammalian transcription and splicing by Nuclear RNAi. Nucleic Acids Res 2016; 44:524-37. [PMID: 26612865 PMCID: PMC4737150 DOI: 10.1093/nar/gkv1305] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 12/21/2022] Open
Abstract
RNA interference (RNAi) is well known as a mechanism for controlling mammalian mRNA translation in the cytoplasm, but what would be the consequences if it also functions in cell nuclei? Although RNAi has also been found in nuclei of plants, yeast, and other organisms, there has been relatively little progress towards understanding the potential involvement of mammalian RNAi factors in nuclear processes including transcription and splicing. This review summarizes evidence for mammalian RNAi factors in cell nuclei and mechanisms that might contribute to the control of gene expression. When RNAi factors bind small RNAs, they form ribonucleoprotein complexes that can be selective for target sequences within different classes of nuclear RNA substrates. The versatility of nuclear RNAi may supply a previously underappreciated layer of regulation to transcription, splicing, and other nuclear processes.
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Affiliation(s)
- Roya Kalantari
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
| | - Cheng-Ming Chiang
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-8807, USA
| | - David R Corey
- Departments of Pharmacology & Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
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38
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Ono M, Yamada K, Avolio F, Afzal V, Bensaddek D, Lamond AI. Targeted Knock-Down of miR21 Primary Transcripts Using snoMEN Vectors Induces Apoptosis in Human Cancer Cell Lines. PLoS One 2015; 10:e0138668. [PMID: 26405811 PMCID: PMC4583369 DOI: 10.1371/journal.pone.0138668] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022] Open
Abstract
We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2.
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Affiliation(s)
- Motoharu Ono
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kayo Yamada
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fabio Avolio
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Vackar Afzal
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Dalila Bensaddek
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I. Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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39
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Matsui M, Li L, Janowski BA, Corey DR. Reduced Expression of Argonaute 1, Argonaute 2, and TRBP Changes Levels and Intracellular Distribution of RNAi Factors. Sci Rep 2015; 5:12855. [PMID: 26242502 PMCID: PMC4525381 DOI: 10.1038/srep12855] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/06/2015] [Indexed: 11/25/2022] Open
Abstract
Until recently, Argonaute 2 (AGO2) and other RNA factors were believed to be restricted to the cytoplasm of mammalian somatic cells. It is now becoming appreciated that RNAi factors can also be found in cell nuclei, but much remains to be learned about their transport, molecular recognition, and function. We find that siRNA-mediated reduction of AGO1 or AGO2 increases the proportion of AGO1 or AGO2 in cell nuclei. Inhibition of AGO1 expression led to increased AGO2 levels, while knockdown of AGO2 led to increased levels of AGO1. Blocking AGO1, AGO2, or TRBP expression changed expression levels and nuclear distribution of RNAi factors Dicer, TNRC6A (GW182), and TRBP. These data reveal the expression of RNAi proteins is mutually dependent and that perturbation can affect subcellular distribution of those factors inside cells.
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Affiliation(s)
- Masayuki Matsui
- Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9041
| | - Liande Li
- Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9041
| | - Bethany A Janowski
- Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9041
| | - David R Corey
- Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9041
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40
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Liu J, Hu J, Hicks JA, Prakash TP, Corey DR. Modulation of Splicing by Single-Stranded Silencing RNAs. Nucleic Acid Ther 2015; 25:113-20. [PMID: 25757055 DOI: 10.1089/nat.2014.0527] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Single-stranded silencing RNAs (ss-siRNAs) are chemically modified single-stranded oligonucleotides that can function through the cellular RNA interference (RNAi) machinery to modulate gene expression. Because their invention is recent, few studies have appeared describing their use and the potential of ss-siRNAs as a platform for controlling gene expression remains largely unknown. Using oligonucleotides to modulate splicing is an important area for therapeutic development and we tested the hypothesis that ss-siRNAs targeting splice sites might also be capable of directing increased production of therapeutically promising protein isoforms. Here we observe that ss-siRNAs alter splicing of dystrophin. Altered splicing requires a seed sequence complementarity to the target and expression of the RNAi factor argonaute 2. These results demonstrate that ss-siRNAs can be used to modulate splicing, providing another option for therapeutic development programs that aim to increase production of key protein isoforms. Splicing is a classical nuclear process and our data showing that it can be modulated through the action of RNA and RNAi factors offers further evidence that RNAi can take place in mammalian cell nuclei.
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Affiliation(s)
- Jing Liu
- 1Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.,2Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Jiaxin Hu
- 1Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.,2Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - Jessica A Hicks
- 1Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.,2Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | | | - David R Corey
- 1Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.,2Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
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41
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Abstract
Argonaute proteins can be found in all three domains of life. In eukaryotic organisms, Argonaute is, as the functional core of the RNA-silencing machinery, critically involved in the regulation of gene expression. Despite the mechanistic and structural similarities between archaeal, bacterial and eukaryotic Argonaute proteins, the biological function of bacterial and archaeal Argonautes has remained elusive. This review discusses new findings in the field that shed light on the structure and function of Argonaute. We especially focus on archaeal Argonautes when discussing the details of the structural and dynamic features in Argonaute that promote substrate recognition and cleavage, thereby revealing differences and similarities in Argonaute biology.
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42
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Wang HLV, Dinwiddie BL, Lee H, Chekanova JA. Stress-induced endogenous siRNAs targeting regulatory intron sequences in Brachypodium. RNA (NEW YORK, N.Y.) 2015; 21:145-63. [PMID: 25480817 PMCID: PMC4338343 DOI: 10.1261/rna.047662.114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Exposure to abiotic stresses triggers global changes in the expression of thousands of eukaryotic genes at the transcriptional and post-transcriptional levels. Small RNA (smRNA) pathways and splicing both function as crucial mechanisms regulating stress-responsive gene expression. However, examples of smRNAs regulating gene expression remain largely limited to effects on mRNA stability, translation, and epigenetic regulation. Also, our understanding of the networks controlling plant gene expression in response to environmental changes, and examples of these regulatory pathways intersecting, remains limited. Here, to investigate the role of smRNAs in stress responses we examined smRNA transcriptomes of Brachypodium distachyon plants subjected to various abiotic stresses. We found that exposure to different abiotic stresses specifically induced a group of novel, endogenous small interfering RNAs (stress-induced, UTR-derived siRNAs, or sutr-siRNAs) that originate from the 3' UTRs of a subset of coding genes. Our bioinformatics analyses predicted that sutr-siRNAs have potential regulatory functions and that over 90% of sutr-siRNAs target intronic regions of many mRNAs in trans. Importantly, a subgroup of these sutr-siRNAs target the important intron regulatory regions, such as branch point sequences, that could affect splicing. Our study indicates that in Brachypodium, sutr-siRNAs may affect splicing by masking or changing accessibility of specific cis-elements through base-pairing interactions to mediate gene expression in response to stresses. We hypothesize that this mode of regulation of gene expression may also serve as a general mechanism for regulation of gene expression in plants and potentially in other eukaryotes.
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Affiliation(s)
- Hsiao-Lin V Wang
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
| | - Brandon L Dinwiddie
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
| | - Herman Lee
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
| | - Julia A Chekanova
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
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43
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Thomson DW, Pillman KA, Anderson ML, Lawrence DM, Toubia J, Goodall GJ, Bracken CP. Assessing the gene regulatory properties of Argonaute-bound small RNAs of diverse genomic origin. Nucleic Acids Res 2015; 43:470-81. [PMID: 25452337 PMCID: PMC4288155 DOI: 10.1093/nar/gku1242] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/23/2014] [Accepted: 11/11/2014] [Indexed: 12/21/2022] Open
Abstract
High-throughput sequencing reveals an abundance of microRNA-sized fragments derived from larger non-coding RNAs. Roles for these small RNAs in gene silencing are suggested by their co-precipitation with Argonaute, the microRNA effector protein, though the extent to which they suppress gene expression endogenously remains unclear. To address this, we used luciferase reporters to determine the endogenous functionality of small RNAs from a diverse range of sources. We demonstrate small RNAs derived from snoRNAs have the capacity to act in a microRNA-like manner, though we note the vast majority of these are bound to Argonaute at levels below that required for detectable silencing activity. We show Argonaute exhibits a high degree of selectivity for the small RNAs with which it interacts and note that measuring Argonaute-associated levels is a better indicator of function than measuring total expression. Although binding to Argonaute at sufficient levels is necessary for demonstrating microRNA functionality in our reporter assay, this alone is not enough as some small RNAs derived from other non-coding RNAs (tRNAs, rRNAs, Y-RNAs) are associated with Argonaute at very high levels yet do not serve microRNA-like roles.
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Affiliation(s)
- Daniel W Thomson
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia
| | - Katherine A Pillman
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - Matthew L Anderson
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - David M Lawrence
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Australian Cancer Research Foundation (ACRF) Cancer Genomics Facility, Adelaide, SA 5005, Australia
| | - John Toubia
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - Gregory J Goodall
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Cameron P Bracken
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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44
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Rigo F, Seth PP, Bennett CF. Antisense oligonucleotide-based therapies for diseases caused by pre-mRNA processing defects. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:303-52. [PMID: 25201110 DOI: 10.1007/978-1-4939-1221-6_9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Before a messenger RNA (mRNA) is translated into a protein in the cytoplasm, its pre-mRNA precursor is extensively processed through capping, splicing and polyadenylation in the nucleus. Defects in the processing of pre-mRNAs due to mutations in RNA sequences often cause disease. Traditional small molecules or protein-based therapeutics are not well suited for correcting processing defects by targeting RNA. However, antisense oligonucleotides (ASOs) designed to bind RNA by Watson-Crick base pairing can target most RNA transcripts and have emerged as the ideal therapeutic agents for diseases that are caused by pre-mRNA processing defects. Here we review the diverse ASO-based mechanisms that can be exploited to modulate the expression of RNA. We also discuss how advancements in medicinal chemistry and a deeper understanding of the pharmacokinetic and toxicological properties of ASOs have enabled their use as therapeutic agents. We end by describing how ASOs have been used successfully to treat various pre-mRNA processing diseases in animal models.
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Affiliation(s)
- Frank Rigo
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA, USA,
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45
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Belter A, Gudanis D, Rolle K, Piwecka M, Gdaniec Z, Naskręt-Barciszewska MZ, Barciszewski J. Mature miRNAs form secondary structure, which suggests their function beyond RISC. PLoS One 2014; 9:e113848. [PMID: 25423301 PMCID: PMC4244182 DOI: 10.1371/journal.pone.0113848] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 10/30/2014] [Indexed: 12/11/2022] Open
Abstract
The generally accepted model of the miRNA-guided RNA down-regulation suggests that mature miRNA targets mRNA in a nucleotide sequence-specific manner. However, we have shown that the nucleotide sequence of miRNA is not the only determinant of miRNA specificity. Using specific nucleases, T1, V1 and S1 as well as NMR, UV/Vis and CD spectroscopies, we found that miR-21, miR-93 and miR-296 can adopt hairpin and/or homoduplex structures. The secondary structure of those miRNAs in solution is a function of RNA concentration and ionic conditions. Additionally, we have shown that a formation of miRNA hairpin is facilitated by cellular environment.Looking for functional consequences of this observation, we have perceived that structure of these miRNAs resemble RNA aptamers, short oligonucleotides forming a stable 3D structures with a high affinity and specificity for their targets. We compared structures of anti-tenascin C (anti-Tn-C) aptamers, which inhibit brain tumor glioblastoma multiforme (GBM, WHO IV) and selected miRNA. A strong overexpression of miR-21, miR-93 as well Tn-C in GBM may imply some connections between them. The structural similarity of these miRNA hairpins and anti-Tn-C aptamers indicates that miRNAs may function also beyond RISC and are even more sophisticated regulators, that it was previously expected. We think that the knowledge of the miRNA structure may give a new insight into miRNA-dependent gene regulation mechanism and be a step forward in the understanding their function and involvement in cancerogenesis. This may improve design process of anti-miRNA therapeutics.
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Affiliation(s)
- Agnieszka Belter
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Dorota Gudanis
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Katarzyna Rolle
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Monika Piwecka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Zofia Gdaniec
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
| | | | - Jan Barciszewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, ul. Noskowskiego 12/14, 61-704, Poznan, Poland
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46
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Ross JP, Kassir Z. The varied roles of nuclear argonaute-small RNA complexes and avenues for therapy. MOLECULAR THERAPY-NUCLEIC ACIDS 2014; 3:e203. [PMID: 25313622 PMCID: PMC4217078 DOI: 10.1038/mtna.2014.54] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/22/2014] [Indexed: 12/14/2022]
Abstract
Argonautes are highly conserved proteins found in almost all eukaryotes and some bacteria and archaea. In humans, there are eight argonaute proteins evenly distributed across two clades, the Ago clade (AGO1-4) and the Piwi clade (PIWIL1-4). The function of Ago proteins is best characterized by their role in RNA interference (RNAi) and cytoplasmic post-transcriptional gene silencing (PTGS) – which involves the loading of siRNA or miRNA into argonaute to direct silencing of genes at the posttranscriptional or translational level. However, nuclear-localized, as opposed to cytoplasmic, argonaute-small RNA complexes may also orchestrate the mechanistically very different process of transcriptional gene silencing, which results in prevention of transcription from a gene locus by the formation of silent chromatin domains. More recently, the role of argonaute in other aspects of epigenetic regulation of chromatin, alternative splicing and DNA repair is emerging. This review focuses on the activity of nuclear-localized short RNA-argonaute complexes in a mammalian setting and discusses recent in vivo studies employing nuclear-directed sRNA for therapeutic interventions. These studies heed the potential development of RNA-based drugs which induce epigenetic changes in the cell.
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Affiliation(s)
- Jason P Ross
- CSIRO Food and Nutrition Flagship, Sydney, New South Wales, Australia
| | - Zena Kassir
- 1] CSIRO Food and Nutrition Flagship, Sydney, New South Wales, Australia [2] Garvan Institute of Medical Research, Sydney, New South Wales, Australia
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47
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Batsché E, Ameyar-Zazoua M. The influence of Argonaute proteins on alternative RNA splicing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 6:141-56. [DOI: 10.1002/wrna.1264] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 07/28/2014] [Accepted: 07/31/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Eric Batsché
- Institut Pasteur, Dpt Biologie du Développement et Cellules Souches; Unité de Régulation Epigénétique; 75015 Paris France
- URA2578; CNRS
| | - Maya Ameyar-Zazoua
- Institut Pasteur, Dpt Biologie du Développement et Cellules Souches; Unité de Régulation Epigénétique; 75015 Paris France
- URA2578; CNRS
- Laboratoire Epigénétique et Destin Cellulaire, CNRS UMR7216; Université Paris Diderot, Cité Sorbonne Paris; Paris France
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48
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Gagnon KT, Li L, Janowski BA, Corey DR. Analysis of nuclear RNA interference in human cells by subcellular fractionation and Argonaute loading. Nat Protoc 2014; 9:2045-60. [PMID: 25079428 PMCID: PMC4251768 DOI: 10.1038/nprot.2014.135] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
RNAi is well known for its ability to regulate gene expression in the cytoplasm of mammalian cells. In mammalian cell nuclei, however, the impact of RNAi has remained more controversial. A key technical hurdle has been a lack of optimized protocols for the isolation and analysis of cell nuclei. Here we describe a simplified protocol for nuclei isolation from cultured cells that incorporates a method for obtaining nucleoplasmic and chromatin fractions and removing cytoplasmic contamination. Cell fractions can then be used to detect the presence and activity of RNAi factors in the nucleus. We include a method for investigating an early step in RNAi, Argonaute protein loading with small RNAs, which is enabled by our improved extract preparations. This protocol facilitates the characterization of nuclear RNAi, and it can be applied to the analysis of other nuclear proteins and pathways. From cellular fractionation to analysis of Argonaute loading results, this protocol takes 4-6 d to complete.
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Affiliation(s)
- Keith T Gagnon
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Liande Li
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Bethany A Janowski
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - David R Corey
- 1] Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. [2] Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
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49
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Roberts TC. The MicroRNA Biology of the Mammalian Nucleus. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e188. [PMID: 25137140 PMCID: PMC4221600 DOI: 10.1038/mtna.2014.40] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/08/2014] [Indexed: 12/13/2022]
Abstract
MicroRNAs (miRNAs) are a class of genome-encoded small RNAs that are primarily considered to be post-transcriptional negative regulators of gene expression acting in the cytoplasm. Over a decade of research has focused on this canonical paradigm of miRNA function, with many success stories. Indeed, miRNAs have been identified that act as master regulators of a myriad of cellular processes, and many miRNAs are promising therapeutic targets or disease biomarkers. However, it is becoming increasingly apparent that the canonical view of miRNA function is incomplete. Several lines of evidence now point to additional functions for miRNAs in the nucleus of the mammalian cell. The majority of cellular miRNAs are present in both the nucleus and the cytoplasm, and certain miRNAs show specific nuclear enrichment. Additionally, some miRNAs colocalize with sub-nuclear structures such as the nucleolus and chromatin. Multiple components of the miRNA processing machinery are present in the nuclear compartment and are shuttled back and forth across the nuclear envelope. In the nucleus, miRNAs act to regulate the stability of nuclear transcripts, induce epigenetic alterations that either silence or activate transcription at specific gene promoters, and modulate cotranscriptional alternative splicing events. Nuclear miRNA-directed gene regulation constitutes a departure from the prevailing view of miRNA function and as such, warrants detailed further investigation.
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Affiliation(s)
- Thomas C Roberts
- 1] Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA [2] Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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50
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Abstract
Over the recent decade oligonucleotides have become an important new class of molecules, allowing therapeutic intervention through targets previously thought 'undruggable'. One of the new avenues opened up by oligonucleotide-based drugs was specific gene upregulation, which, historically, has been difficult to achieve using small-molecule drugs. This article will focus on patents covering this important development in the oligonucleotide field and highlight the different mechanisms through which the oligonucleotide-mediated gene upregulation can work, including inhibition of activity of natural antisense transcripts, interaction with promoter binding sites of noncoding regulatory RNAs, blocking of regulatory and/or miRNA binding sites in 3' UTRs, blocking splice inhibitor/enhancer sites or blocking interactions with polycomb repressive complex 2. Understanding the particular mechanism through which an oligonucleotide drug exerts its effects is highly important in drug development, as it determines the design of the drug molecule.
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