1
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Smalheiser NR. Mobile circular DNAs regulating memory and communication in CNS neurons. Front Mol Neurosci 2023; 16:1304667. [PMID: 38125007 PMCID: PMC10730651 DOI: 10.3389/fnmol.2023.1304667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/14/2023] [Indexed: 12/23/2023] Open
Abstract
Stimuli that stimulate neurons elicit transcription of immediate-early genes, a process which requires local sites of chromosomal DNA to form double-strand breaks (DSBs) generated by topoisomerase IIb within a few minutes, followed by repair within a few hours. Wakefulness, exploring a novel environment, and contextual fear conditioning also elicit turn-on of synaptic genes requiring DSBs and repair. It has been reported (in non-neuronal cells) that extrachromosomal circular DNA can form at DSBs as the sites are repaired. I propose that activated neurons may generate extrachromosomal circular DNAs during repair at DSB sites, thus creating long-lasting "markers" of that activity pattern which contain sequences from their sites of origin and which regulate long-term gene expression. Although the population of extrachromosomal DNAs is diverse and overall associated with pathology, a subclass of small circular DNAs ("microDNAs," ∼100-400 bases long), largely derives from unique genomic sequences and has attractive features to act as stable, mobile circular DNAs to regulate gene expression in a sequence-specific manner. Circular DNAs can be templates for the transcription of RNAs, particularly small inhibitory siRNAs, circular RNAs and other non-coding RNAs that interact with microRNAs. These may regulate translation and transcription of other genes involved in synaptic plasticity, learning and memory. Another possible fate for mobile DNAs is to be inserted stably into chromosomes after new DSB sites are generated in response to subsequent activation events. Thus, the insertions of mobile DNAs into activity-induced genes may tend to inactivate them and aid in homeostatic regulation to avoid over-excitation, as well as providing a "counter" for a neuron's activation history. Moreover, activated neurons release secretory exosomes that can be transferred to recipient cells to regulate their gene expression. Mobile DNAs may be packaged into exosomes, released in an activity-dependent manner, and transferred to recipient cells, where they may be templates for regulatory RNAs and possibly incorporated into chromosomes. Finally, aging and neurodegenerative diseases (including Alzheimer's disease) are also associated with an increase in DSBs in neurons. It will become important in the future to assess how pathology-associated DSBs may relate to activity-induced mobile DNAs, and whether the latter may potentially contribute to pathogenesis.
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Affiliation(s)
- Neil R. Smalheiser
- Department of Psychiatry, University of Illinois College of Medicine, Chicago, IL, United States
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2
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Luo M, Lee LKC, Peng B, Choi CHJ, Tong WY, Voelcker NH. Delivering the Promise of Gene Therapy with Nanomedicines in Treating Central Nervous System Diseases. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201740. [PMID: 35851766 PMCID: PMC9475540 DOI: 10.1002/advs.202201740] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/19/2022] [Indexed: 06/01/2023]
Abstract
Central Nervous System (CNS) diseases, such as Alzheimer's diseases (AD), Parkinson's Diseases (PD), brain tumors, Huntington's disease (HD), and stroke, still remain difficult to treat by the conventional molecular drugs. In recent years, various gene therapies have come into the spotlight as versatile therapeutics providing the potential to prevent and treat these diseases. Despite the significant progress that has undoubtedly been achieved in terms of the design and modification of genetic modulators with desired potency and minimized unwanted immune responses, the efficient and safe in vivo delivery of gene therapies still poses major translational challenges. Various non-viral nanomedicines have been recently explored to circumvent this limitation. In this review, an overview of gene therapies for CNS diseases is provided and describes recent advances in the development of nanomedicines, including their unique characteristics, chemical modifications, bioconjugations, and the specific applications that those nanomedicines are harnessed to deliver gene therapies.
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Affiliation(s)
- Meihua Luo
- Monash Institute of Pharmaceutics ScienceMonash UniversityParkville Campus, 381 Royal ParadeParkvilleVIC3052Australia
- Australian Institute for Bioengineering and Nanotechnologythe University of QueenslandSt LuciaQLD4072Australia
| | - Leo Kit Cheung Lee
- Department of Biomedical EngineeringThe Chinese University of Hong KongShatinNew TerritoriesHong Kong
| | - Bo Peng
- Monash Institute of Pharmaceutics ScienceMonash UniversityParkville Campus, 381 Royal ParadeParkvilleVIC3052Australia
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical materials & EngineeringNorthwestern Polytechnical UniversityXi'an710072China
| | - Chung Hang Jonathan Choi
- Department of Biomedical EngineeringThe Chinese University of Hong KongShatinNew TerritoriesHong Kong
| | - Wing Yin Tong
- Monash Institute of Pharmaceutics ScienceMonash UniversityParkville Campus, 381 Royal ParadeParkvilleVIC3052Australia
| | - Nicolas H. Voelcker
- Monash Institute of Pharmaceutics ScienceMonash UniversityParkville Campus, 381 Royal ParadeParkvilleVIC3052Australia
- Commonwealth Scientific and Industrial Research Organization (CSIRO)ClaytonVIC3168Australia
- Melbourne Centre for NanofabricationVictorian Node of the Australian National Fabrication Facility151 Wellington RoadClaytonVIC3168Australia
- Materials Science and EngineeringMonash University14 Alliance LaneClaytonVIC3800Australia
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3
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Haehner A, Chen B, Espin M, Haussmann R, Matthes C, Desser D, Loessner L, Brandt MD, Donix M, Hummel T. Training with Odors Impacts Hippocampal Thickness in Patients with Mild Cognitive Impairment. J Alzheimers Dis 2022; 88:743-755. [DOI: 10.3233/jad-220248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: The olfactory system is affected early in Alzheimer’s disease and olfactory loss can already be observed in patients with mild cognitive impairment (MCI). Olfactory training is effective for improving olfactory and cognitive function by stimulating the olfactory pathway, but its effect on patients with MCI remains unclear. Objective: The aim of this randomized, prospective, controlled, blinded study was to assess whether a 4-month period of olfactory training (frequent short-term sniffing various odors) may have an effect on olfactory function, cognitive function, and morphology of medial temporal lobe (MTL) subregions and olfactory bulb in MCI patients. Methods: A total of thirty-seven MCI patients were randomly assigned to the training group or a placebo group, which were performed twice a day for 4 months. Olfactory assessments, cognitive tests and magnetic resonance imaging were performed at the baseline and follow-up period. Results: After the training, there was an increase in odor discrimination, and increased cortical thickness of bilateral hippocampus (CA23DG and CA1) and mean MTL. Additionally, the change of olfactory score was positively associated with change of volume of olfactory bulb and hippocampus; the change of global cognition was positively associated with change of cortical thickness of hippocampus, entorhinal cortex and mean MTL; the change of cortical thickness of entorhinal cortex was positively associated with change of executive function. Conclusion: Olfactory training was associated with an increase in cortical thickness of the hippocampus but not olfactory bulb volume in patients with MCI. Olfactory training may serve as an early intervention of preventing hippocampal atrophy.
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Affiliation(s)
| | - Ben Chen
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- Memory Clinic, Department of Geriatric Psychiatry, The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong Province, China
| | - Melanie Espin
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | | | | | - Dmitriy Desser
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | | | - Moritz D. Brandt
- Department of Neurology, TU Dresden, Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Markus Donix
- Department of Psychiatry, TU Dresden, Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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4
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Ow MC, Hall SE. piRNAs and endo-siRNAs: Small molecules with large roles in the nervous system. Neurochem Int 2021; 148:105086. [PMID: 34082061 PMCID: PMC8286337 DOI: 10.1016/j.neuint.2021.105086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 04/23/2021] [Accepted: 05/26/2021] [Indexed: 01/02/2023]
Abstract
Since their discovery, small non-coding RNAs have emerged as powerhouses in the regulation of numerous cellular processes. In addition to guarding the integrity of the reproductive system, small non-coding RNAs play critical roles in the maintenance of the soma. Accumulating evidence indicates that small non-coding RNAs perform vital functions in the animal nervous system such as restricting the activity of deleterious transposable elements, regulating nerve regeneration, and mediating learning and memory. In this review, we provide an overview of the current understanding of the contribution of two major classes of small non-coding RNAs, piRNAs and endo-siRNAs, to the nervous system development and function, and present highlights on how the dysregulation of small non-coding RNA pathways can assist in understanding the neuropathology of human neurological disorders.
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Affiliation(s)
- Maria C Ow
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
| | - Sarah E Hall
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
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5
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Roy R, Shiina N, Wang DO. More dynamic, more quantitative, unexpectedly intricate: Advanced understanding on synaptic RNA localization in learning and memory. Neurobiol Learn Mem 2019; 168:107149. [PMID: 31881355 DOI: 10.1016/j.nlm.2019.107149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/25/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023]
Abstract
Synaptic signaling exhibits great diversity, complexity, and plasticity which necessitates maintenance and rapid modification of a local proteome. One solution neurons actively exploit to meet such demands is the strategic deposition of mRNAs encoding proteins for both basal and experience-driven activities into ribonucleoprotein complexes at the synapse. Transcripts localized in this manner can be rapidly accessed for translation in response to a diverse range of stimuli in a temporal- and spatially-restricted manner. Here we review recent findings on localized RNAs and RNA binding proteins in the context of learning and memory, as revealed by cutting-edge in-vitro and in-vivo technologies capable of yielding quantitative and dynamic information. The new technologies include proteomic and transcriptomic analyses, high-resolution multiplexed RNA imaging, single-molecule RNA tracking in living neurons, animal models and human neuron cell models. Among many recent advances in the field, RNA chemical modification has emerged as one of the new regulatory layers of gene expression at synapse that is complex and yet largely unexplored. These exciting new discoveries have enhanced our understanding of the modulation mechanisms of synaptic gene expression and their roles in cognition.
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Affiliation(s)
- Rohini Roy
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, SOKENDAI, Okazaki, Japan; Exploratory Research Center on Life and Living Systems, Okazaki, Japan.
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Liaoning, China; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; The Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research (K-CONNEX), Kyoto University, Kyoto, Japan.
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6
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Demeter T, Vaskovicova M, Malik R, Horvat F, Pasulka J, Svobodova E, Flemr M, Svoboda P. Main constraints for RNAi induced by expressed long dsRNA in mouse cells. Life Sci Alliance 2019; 2:2/1/e201800289. [PMID: 30808654 PMCID: PMC6391682 DOI: 10.26508/lsa.201800289] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/09/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022] Open
Abstract
A systematic survey of dsRNA expression in mouse fibroblasts and embryonic stem cells shows main constraints for RNAi. RNAi activity depends on the initial Dicer cleavage of dsRNA, having implications for the evolution of mammalian RNAi functions. RNAi is the sequence-specific mRNA degradation guided by siRNAs produced from long dsRNA by RNase Dicer. Proteins executing RNAi are present in mammalian cells but rather sustain the microRNA pathway. Aiming for a systematic analysis of mammalian RNAi, we report here that the main bottleneck for RNAi efficiency is the production of functional siRNAs, which integrates Dicer activity, dsRNA structure, and siRNA targeting efficiency. Unexpectedly, increased expression of Dicer cofactors TARBP2 or PACT reduces RNAi but not microRNA function. Elimination of protein kinase R, a key dsRNA sensor in the interferon response, had minimal positive effects on RNAi activity in fibroblasts. Without high Dicer activity, RNAi can still occur when the initial Dicer cleavage of the substrate yields an efficient siRNA. Efficient mammalian RNAi may use substrates with some features of microRNA precursors, merging both pathways even more than previously suggested. Although optimized endogenous Dicer substrates mimicking miRNA features could evolve for endogenous regulations, the same principles would make antiviral RNAi inefficient as viruses would adapt to avoid efficacy.
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Affiliation(s)
- Tomas Demeter
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Michaela Vaskovicova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Radek Malik
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Filip Horvat
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.,Bioinformatics Group, Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Josef Pasulka
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Eliska Svobodova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Matyas Flemr
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Petr Svoboda
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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7
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Oliver RJ, Mandyam CD. Regulation of Adult Neurogenesis by Non-coding RNAs: Implications for Substance Use Disorders. Front Neurosci 2018; 12:849. [PMID: 30524229 PMCID: PMC6261985 DOI: 10.3389/fnins.2018.00849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/30/2018] [Indexed: 12/25/2022] Open
Abstract
The discovery of non-coding RNAs (ncRNAs)has been one of the central findings from early genomic sequencing studies. Not only was the presence of these genes unknown previously, it was the staggering disproportionate share of the genome that was predicted to be encoded by ncRNAs that was truly significant in genomic research. Over the years the function of various classes of these ncRNAs has been revealed. One of the first and enduring regulatory programs associated with these factors was development. In the neurosciences, the discovery of adult derived populations of dividing cells within the brain was equally substantial. The brain was hypothesized to be plastic only in its neuronal connectivity, but the discovery of the generation of new neurons was a novel mechanism of neuronal and behavioral plasticity. The process of adult neurogenesis resembles early neuronal development and has been found to share many parallels in the proper stages of specified genetic programs. Adult neurogenesis has also been found to play a role in learning and memory involved in particular hippocampal-dependent behaviors. Substance use disorders (SUDs) are an example of a behavioral condition that is associated with and possibly driven by hippocampal alterations. Our laboratory has determined that hippocampal adult neurogenesis is necessary for a rodent model of methamphetamine relapse. Due to the previous research on ncRNAs in development and in other brain regions involved in SUDs, we posit that ncRNAs may play a role in adult neurogenesis associated with this disorder. This review will cover the regulatory mechanisms of various classes of ncRNAs on the coordinated genetic program associated with adult neurogenesis with a special focus on how these programs could be dysregulated in SUDs.
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Affiliation(s)
- Robert J Oliver
- VA San Diego Healthcare System, San Diego, CA, United States
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Anesthesiology, University of California, San Diego, San Diego, CA, United States
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8
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Leighton LJ, Bredy TW. Functional Interplay between Small Non-Coding RNAs and RNA Modification in the Brain. Noncoding RNA 2018; 4:E15. [PMID: 29880782 PMCID: PMC6027130 DOI: 10.3390/ncrna4020015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/23/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022] Open
Abstract
Small non-coding RNAs are essential for transcription, translation and gene regulation in all cell types, but are particularly important in neurons, with known roles in neurodevelopment, neuroplasticity and neurological disease. Many small non-coding RNAs are directly involved in the post-transcriptional modification of other RNA species, while others are themselves substrates for modification, or are functionally modulated by modification of their target RNAs. In this review, we explore the known and potential functions of several distinct classes of small non-coding RNAs in the mammalian brain, focusing on the newly recognised interplay between the epitranscriptome and the activity of small RNAs. We discuss the potential for this relationship to influence the spatial and temporal dynamics of gene activation in the brain, and predict that further research in the field of epitranscriptomics will identify interactions between small RNAs and RNA modifications which are essential for higher order brain functions such as learning and memory.
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Affiliation(s)
- Laura J Leighton
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Timothy W Bredy
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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9
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Abstract
The emerging complexity of the transcriptional landscape poses great challenges to our conventional preconceptions of how the genome regulates brain function and dysfunction. Non-protein-coding RNAs (ncRNAs) confer a high level of intricate and dynamic regulation of various molecular processes in the CNS and they have been implicated in neurodevelopment and brain ageing, as well as in synapse function and cognitive performance, in both health and disease. ncRNA-mediated processes may be involved in various aspects of the pathogenesis of neurodegenerative disorders. Understanding these events may help to develop novel diagnostic and therapeutic tools. Here, we provide an overview of the complex mechanisms that are affected by the diverse ncRNA classes that have been implicated in neurodegeneration.
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10
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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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11
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Roles for small noncoding RNAs in silencing of retrotransposons in the mammalian brain. Proc Natl Acad Sci U S A 2016; 113:12697-12702. [PMID: 27791114 DOI: 10.1073/pnas.1609287113] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs), long thought to be restricted to germline, have recently been discovered in neurons of Aplysia, with a role in the epigenetic regulation of gene expression underlying long-term memory. We here ask whether piwi/piRNAs are also expressed and have functional roles in the mammalian brain. Large-scale RNA sequencing and subsequent analysis of protein expression revealed the presence in brain of several piRNA biogenesis factors including a mouse piwi (Mili), as well as small RNAs, albeit at low levels, resembling conserved piRNAs in mouse testes [primarily LINE1 (long interspersed nuclear element1) retrotransposon-derived]. Despite the seeming low expression of these putative piRNAs, single-base pair CpG methylation analyses across the genome of Mili/piRNA-deficient (Mili-/- ) mice demonstrate that brain genomic DNA is preferentially hypomethylated within intergenic areas and LINE1 promoter areas of the genome. Furthermore, Mili mutant mice exhibit behavioral deficits such as hyperactivity and reduced anxiety. These results suggest that putative piRNAs exist in mammalian brain, and similar to the role of piRNAs in testes, they may be involved in the silencing of retrotransposons, which in brain have critical roles in contributing to genomic heterogeneity underlying adaptation, stress response, and brain pathology. We also describe the presence of another class of small RNAs in the brain, with features of endogenous siRNAs, which may have taken over the role of invertebrate piRNAs in their capacity to target both transposons, as well as protein-coding genes. Thus, RNA interference through gene and retrotransposon silencing previously encountered in Aplysia may also have potential roles in the mammalian brain.
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12
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Svobodova E, Kubikova J, Svoboda P. Production of small RNAs by mammalian Dicer. Pflugers Arch 2016; 468:1089-102. [PMID: 27048428 PMCID: PMC4893058 DOI: 10.1007/s00424-016-1817-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/20/2016] [Accepted: 03/24/2016] [Indexed: 01/16/2023]
Abstract
MicroRNA (miRNA) and RNA interference (RNAi) pathways employ RNase III Dicer for the biogenesis of small RNAs guiding post-transcriptional repression. Requirements for Dicer activity differ in the two pathways. The biogenesis of miRNAs requires a single Dicer cleavage of a short hairpin precursor to produce a small RNA with a precisely defined sequence, while small RNAs in RNAi come from a processive cleavage of a long double-stranded RNA (dsRNA) into a pool of small RNAs with different sequences. While Dicer is generally conserved among eukaryotes, its substrate recognition, cleavage, and biological roles differ. In Metazoa, a single Dicer can function as a universal factor for RNAi and miRNA pathways or as a factor adapted specifically for one of the pathways. In this review, we focus on the structure, function, and evolution of mammalian Dicer. We discuss key structural features of Dicer and other factors defining Dicer substrate repertoire and biological functions in mammals in comparison with invertebrate models. The key for adaptation of Dicer for miRNA or RNAi pathways is the N-terminal helicase, a dynamically evolving Dicer domain. Its functionality differs between mammals and invertebrates: the mammalian Dicer is well adapted to produce miRNAs while its ability to support RNAi is limited.
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Affiliation(s)
- Eliska Svobodova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Jana Kubikova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Petr Svoboda
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic.
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13
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Wang HLV, Chekanova JA. Small RNAs: essential regulators of gene expression and defenses against environmental stresses in plants. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:356-81. [PMID: 26924473 DOI: 10.1002/wrna.1340] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 12/28/2015] [Accepted: 12/30/2015] [Indexed: 12/18/2022]
Abstract
Eukaryotic genomes produce thousands of diverse small RNAs (smRNAs), which play vital roles in regulating gene expression in all conditions, including in survival of biotic and abiotic environmental stresses. SmRNA pathways intersect with most of the pathways regulating different steps in the life of a messenger RNA (mRNA), starting from transcription and ending at mRNA decay. SmRNAs function in both nuclear and cytoplasmic compartments; the regulation of mRNA stability and translation in the cytoplasm and the epigenetic regulation of gene expression in the nucleus are the main and best-known modes of smRNA action. However, recent evidence from animal systems indicates that smRNAs and RNA interference (RNAi) also participate in the regulation of alternative pre-mRNA splicing, one of the most crucial steps in the fast, efficient global reprogramming of gene expression required for survival under stress. Emerging evidence from bioinformatics studies indicates that a specific class of plant smRNAs, induced by various abiotic stresses, the sutr-siRNAs, has the potential to target regulatory regions within introns and thus may act in the regulation of splicing in response to stresses. This review summarizes the major types of plant smRNAs in the context of their mechanisms of action and also provides examples of their involvement in regulation of gene expression in response to environmental cues and developmental stresses. In addition, we describe current advances in our understanding of how smRNAs function in the regulation of pre-mRNA splicing. WIREs RNA 2016, 7:356-381. doi: 10.1002/wrna.1340 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Hsiao-Lin V Wang
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Julia A Chekanova
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO, USA
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14
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Yu D, Meng Y, Zuo Z, Xue J, Wang H. NATpipe: an integrative pipeline for systematical discovery of natural antisense transcripts (NATs) and phase-distributed nat-siRNAs from de novo assembled transcriptomes. Sci Rep 2016; 6:21666. [PMID: 26858106 PMCID: PMC4746697 DOI: 10.1038/srep21666] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/28/2016] [Indexed: 12/12/2022] Open
Abstract
Nat-siRNAs (small interfering RNAs originated from natural antisense transcripts) are a class of functional small RNA (sRNA) species discovered in both plants and animals. These siRNAs are highly enriched within the annealed regions of the NAT (natural antisense transcript) pairs. To date, great research efforts have been taken for systematical identification of the NATs in various organisms. However, developing a freely available and easy-to-use program for NAT prediction is strongly demanded by researchers. Here, we proposed an integrative pipeline named NATpipe for systematical discovery of NATs from de novo assembled transcriptomes. By utilizing sRNA sequencing data, the pipeline also allowed users to search for phase-distributed nat-siRNAs within the perfectly annealed regions of the NAT pairs. Additionally, more reliable nat-siRNA loci could be identified based on degradome sequencing data. A case study on the non-model plant Dendrobium officinale was performed to illustrate the utility of NATpipe. Finally, we hope that NATpipe would be a useful tool for NAT prediction, nat-siRNA discovery, and related functional studies. NATpipe is available at www.bioinfolab.cn/NATpipe/NATpipe.zip.
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Affiliation(s)
- Dongliang Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China
| | - Yijun Meng
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China.,Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Ziwei Zuo
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China.,Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Jie Xue
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China.,Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
| | - Huizhong Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China.,Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou 310036, China
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15
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Lugli G, Kataria Y, Richards Z, Gann P, Zhou X, Nonn L. Laser-capture Microdissection of Human Prostatic Epithelium for RNA Analysis. J Vis Exp 2015. [PMID: 26651078 DOI: 10.3791/53405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The prostate gland contains a heterogeneous milieu of stromal, epithelial, neuroendocrine and immune cell types. Healthy prostate is comprised of fibromuscular stroma surrounding discrete epithelial-lined secretory lumens and a very small population of immune and neuroendocrine cells. In contrast, areas of prostate cancer have increased dysplastic luminal epithelium with greatly reduced or absent stromal population. Given the profound difference between stromal and epithelial cell types, it is imperative to separate the cell types for any type of downstream molecular analysis. Despite this knowledge, the bulk of gene expression studies compare benign prostate to cancer without micro-dissection, leading to stromal bias in the benign samples. Laser-capture micro-dissection (LCM) is an effective method to physically separate different cell types from a specimen section. The goal of this protocol is to show that RNA can be successfully isolated from LCM-collected human prostatic epithelium and used for downstream gene expression studies such as RT-qPCR and RNAseq.
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Affiliation(s)
- Giovanni Lugli
- Department of Pathology, University of Illinois at Chicago
| | | | | | - Peter Gann
- Department of Pathology, University of Illinois at Chicago
| | - Xiaofeng Zhou
- Department of Periodontics, University of Illinois at Chicago
| | - Larisa Nonn
- Department of Pathology, University of Illinois at Chicago;
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16
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Butler AA, Webb WM, Lubin FD. Regulatory RNAs and control of epigenetic mechanisms: expectations for cognition and cognitive dysfunction. Epigenomics 2015; 8:135-51. [PMID: 26366811 DOI: 10.2217/epi.15.79] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The diverse functions of noncoding RNAs (ncRNAs) can influence virtually every aspect of the transcriptional process including epigenetic regulation of genes. In the CNS, regulatory RNA networks and epigenetic mechanisms have broad relevance to gene transcription changes involved in long-term memory formation and cognition. Thus, it is becoming increasingly clear that multiple classes of ncRNAs impact neuronal development, neuroplasticity, and cognition. Currently, a large gap exists in our knowledge of how ncRNAs facilitate epigenetic processes, and how this phenomenon affects cognitive function. In this review, we discuss recent findings highlighting a provocative role for ncRNAs including lncRNAs and piRNAs in the control of epigenetic mechanisms involved in cognitive function. Furthermore, we discuss the putative roles for these ncRNAs in cognitive disorders such as schizophrenia and Alzheimer's disease.
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Affiliation(s)
- Anderson A Butler
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - William M Webb
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
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17
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Pundhir S, Gorodkin J. Differential and coherent processing patterns from small RNAs. Sci Rep 2015; 5:12062. [PMID: 26166713 PMCID: PMC4499813 DOI: 10.1038/srep12062] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/16/2015] [Indexed: 12/16/2022] Open
Abstract
Post-transcriptional processing events related to short RNAs are often reflected in their read profile patterns emerging from high-throughput sequencing data. MicroRNA arm switching across different tissues is a well-known example of what we define as differential processing. Here, short RNAs from the nine cell lines of the ENCODE project, irrespective of their annotation status, were analyzed for genomic loci representing differential or coherent processing. We observed differential processing predominantly in RNAs annotated as miRNA, snoRNA or tRNA. Four out of five known cases of differentially processed miRNAs that were in the input dataset were recovered and several novel cases were discovered. In contrast to differential processing, coherent processing is observed widespread in both annotated and unannotated regions. While the annotated loci predominantly consist of ~24 nt short RNAs, the unannotated loci comparatively consist of ~17 nt short RNAs. Furthermore, these ~17 nt short RNAs are significantly enriched for overlap to transcription start sites and DNase I hypersensitive sites (p-value < 0.01) that are characteristic features of transcription initiation RNAs. We discuss how the computational pipeline developed in this study has the potential to be applied to other forms of RNA-seq data for further transcriptome-wide studies of differential and coherent processing.
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Affiliation(s)
- Sachin Pundhir
- Center for non-coding RNA in Technology and Health, IKVH, University of Copenhagen, Grønnegårdsvej 3, 1870, Frederiksberg C, Denmark
| | - Jan Gorodkin
- Center for non-coding RNA in Technology and Health, IKVH, University of Copenhagen, Grønnegårdsvej 3, 1870, Frederiksberg C, Denmark
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18
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Weiß K, Antoniou A, Schratt G. Non-coding mechanisms of local mRNA translation in neuronal dendrites. Eur J Cell Biol 2015; 94:363-7. [DOI: 10.1016/j.ejcb.2015.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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19
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Smalheiser NR. The RNA-centred view of the synapse: non-coding RNAs and synaptic plasticity. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0504. [PMID: 25135965 PMCID: PMC4142025 DOI: 10.1098/rstb.2013.0504] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
If mRNAs were the only RNAs made by a neuron, there would be a simple mapping of mRNAs to proteins. However, microRNAs and other non-coding RNAs (ncRNAs; endo-siRNAs, piRNAs, BC1, BC200, antisense and long ncRNAs, repeat-related transcripts, etc.) regulate mRNAs via effects on protein translation as well as transcriptional and epigenetic mechanisms. Not only are genes ON or OFF, but their ability to be translated can be turned ON or OFF at the level of synapses, supporting an enormous increase in information capacity. Here, I review evidence that ncRNAs are expressed pervasively within dendrites in mammalian brain; that some are activity-dependent and highly enriched near synapses; and that synaptic ncRNAs participate in plasticity responses including learning and memory. Ultimately, ncRNAs can be viewed as the post-it notes of the neuron. They have no literal meaning of their own, but derive their functions from where (and to what) they are stuck. This may explain, in part, why ncRNAs differ so dramatically from protein-coding genes, both in terms of the usual indicators of functionality and in terms of evolutionary constraints. ncRNAs do not appear to be direct mediators of synaptic transmission in the manner of neurotransmitters or receptors, yet they orchestrate synaptic plasticity—and may drive species-specific changes in cognition.
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Affiliation(s)
- Neil R Smalheiser
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA
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20
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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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21
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Shin J, Ming GL, Song H. Decoding neural transcriptomes and epigenomes via high-throughput sequencing. Nat Neurosci 2014; 17:1463-75. [PMID: 25349913 DOI: 10.1038/nn.3814] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/14/2014] [Indexed: 02/07/2023]
Abstract
The mammalian brain is an evolutionary marvel in which engraving and re-engraving of cellular states enable complex information processing and lifelong maintenance. Understanding the mechanisms by which neurons alter and maintain their molecular signatures during information processing is a fundamental goal of neuroscience. Next-generation sequencing (NGS) technology is rapidly transforming the ability to probe the molecular basis of neuronal function. NGS can define not only the complete molecular signatures of cells by transcriptome analyses but also the cascade of events that induce or maintain such signatures by epigenetic analyses. Here we offer some general and practical information to demystify NGS technology and highlight its potential to the neuroscience field. We start with discussion of the complexity of the nervous system, then introduce various applications of NGS with practical considerations and describe basic principles underlying various NGS technologies. Finally, we discuss emerging NGS-related technologies for the neuroscience field.
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Affiliation(s)
- Jaehoon Shin
- 1] Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [2] Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Guo-li Ming
- 1] Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [2] Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [3] Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [4] The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hongjun Song
- 1] Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [2] Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [3] Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [4] The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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22
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Thomas MG, Pascual ML, Maschi D, Luchelli L, Boccaccio GL. Synaptic control of local translation: the plot thickens with new characters. Cell Mol Life Sci 2014; 71:2219-39. [PMID: 24212248 PMCID: PMC11113725 DOI: 10.1007/s00018-013-1506-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 12/18/2022]
Abstract
The production of proteins from mRNAs localized at the synapse ultimately controls the strength of synaptic transmission, thereby affecting behavior and cognitive functions. The regulated transcription, processing, and transport of mRNAs provide dynamic control of the dendritic transcriptome, which includes thousands of messengers encoding multiple cellular functions. Translation is locally modulated by synaptic activity through a complex network of RNA-binding proteins (RBPs) and various types of non-coding RNAs (ncRNAs) including BC-RNAs, microRNAs, piwi-interacting RNAs, and small interference RNAs. The RBPs FMRP and CPEB play a well-established role in synaptic translation, and additional regulatory factors are emerging. The mRNA repressors Smaug, Nanos, and Pumilio define a novel pathway for local translational control that affects dendritic branching and spines in both flies and mammals. Recent findings support a role for processing bodies and related synaptic mRNA-silencing foci (SyAS-foci) in the modulation of synaptic plasticity and memory formation. The SyAS-foci respond to different stimuli with changes in their integrity thus enabling regulated mRNA release followed by translation. CPEB, Pumilio, TDP-43, and FUS/TLS form multimers through low-complexity regions related to prion domains or polyQ expansions. The oligomerization of these repressor RBPs is mechanistically linked to the aggregation of abnormal proteins commonly associated with neurodegeneration. Here, we summarize the current knowledge on how specificity in mRNA translation is achieved through the concerted action of multiple pathways that involve regulatory ncRNAs and RBPs, the modification of translation factors, and mRNA-silencing foci dynamics.
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Affiliation(s)
- María Gabriela Thomas
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
| | - Malena Lucía Pascual
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Buenos Aires, Argentina
| | - Darío Maschi
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- Present Address: Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO USA
| | - Luciana Luchelli
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
| | - Graciela Lidia Boccaccio
- Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
- IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Buenos Aires, Argentina
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23
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Svoboda P. Renaissance of mammalian endogenous RNAi. FEBS Lett 2014; 588:2550-6. [DOI: 10.1016/j.febslet.2014.05.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 05/16/2014] [Accepted: 05/19/2014] [Indexed: 01/03/2023]
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24
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Yamazaki F, Kim HH, Lau P, Hwang CK, Iuvone PM, Klein D, Clokie SJH. pY RNA1-s2: a highly retina-enriched small RNA that selectively binds to Matrin 3 (Matr3). PLoS One 2014; 9:e88217. [PMID: 24558381 PMCID: PMC3928194 DOI: 10.1371/journal.pone.0088217] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/03/2014] [Indexed: 12/22/2022] Open
Abstract
The purpose of this study was to expand our knowledge of small RNAs, which are known to function within protein complexes to modulate the transcriptional output of the cell. Here we describe two previously unrecognized, small RNAs, termed pY RNA1-s1 and pY RNA1-s2 (processed Y RNA1-stem −1 and −2), thereby expanding the list of known small RNAs. pY RNA1-s1 and pY RNA1-s2 were discovered by RNA sequencing and found to be 20-fold more abundant in the retina than in 14 other rat tissues. Retinal expression of pY RNAs is highly conserved, including expression in the human retina, and occurs in all retinal cell layers. Mass spectrometric analysis of pY RNA1-S2 binding proteins in retina indicates that pY RNA1-s2 selectively binds the nuclear matrix protein Matrin 3 (Matr3) and to a lesser degree to hnrpul1 (heterogeneous nuclear ribonucleoprotein U-like protein). In contrast, pY RNA1-s1 does not bind these proteins. Accordingly, the molecular mechanism of action of pY RNA1-s2 is likely be through an action involving Matr3; this 95 kDa protein has two RNA recognition motifs (RRMs) and is implicated in transcription and RNA-editing. The high affinity binding of pY RNA1-s2 to Matr3 is strongly dependent on the sequence of the RNA and both RRMs of Matr3. Related studies also indicate that elements outside of the RRM region contribute to binding specificity and that phosphorylation enhances pY RNA-s2/Matr3 binding. These observations are of significance because they reveal that a previously unrecognized small RNA, pY RNA1-s2, binds selectively to Matr3. Hypothetically, pY RNA1-S2 might act to modulate cellular function through this molecular mechanism. The retinal enrichment of pY RNA1-s2 provides reason to suspect that the pY RNA1-s2/Matr3 interaction could play a role in vision.
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Affiliation(s)
- Fumiyoshi Yamazaki
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hyun Hee Kim
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Pierre Lau
- Division of intramural research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christopher K. Hwang
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - David Klein
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Samuel J. H. Clokie
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
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25
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Smalheiser NR, Lugli G, Zhang H, Rizavi H, Cook EH, Dwivedi Y. Expression of microRNAs and other small RNAs in prefrontal cortex in schizophrenia, bipolar disorder and depressed subjects. PLoS One 2014; 9:e86469. [PMID: 24475125 PMCID: PMC3903529 DOI: 10.1371/journal.pone.0086469] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/10/2013] [Indexed: 12/18/2022] Open
Abstract
Because of the role played by miRNAs in post-transcriptional regulation of an array of genes, their impact in neuropsychiatric disease pathophysiology has increasingly been evident. In the present study, we assessed microRNA expression in prefrontal cortex (Brodmann area 10) of a well-characterized cohort of major depressed, bipolar, and schizophrenia subjects (obtained from Stanley Neuropathology Consortium; n = 15 in each group), using high throughput RT-PCR plates. Discrete miRNA alterations were observed in all disorders, as well as in suicide subjects (pooled across diagnostic categories) compared to all non-suicide subjects. The changes in the schizophrenia group were partially similar to those in the bipolar group, but distinct from changes in depression and suicide. Intriguingly, those miRNAs which were down-regulated in the schizophrenia group tended to be synaptically enriched, whereas up-regulated miRNAs tended not to be. To follow this up, we purified synaptosomes from pooled samples of the schizophrenia vs. control groups and subjected them to Illumina deep sequencing. There was a significant loss of small RNA expression in schizophrenia synaptosomes only for certain sequence lengths within the miRNA range. Moreover, 73 miRNAs were significantly down-regulated whereas only one was up-regulated. Strikingly, across all expressed miRNAs in synaptosomes, there was a significant inverse correlation between the fold-change of a given miRNA seen in schizophrenia and its synaptic enrichment ratio observed in controls. Thus, synaptic miRNAs tended to be down-regulated in schizophrenia, and the more highly synaptically enriched miRNAs tended to show greater down-regulation. These findings point to some deficit in miRNA biogenesis, transport, processing or turnover in schizophrenia that is selective for the synaptic compartment. A novel class of ncRNA-derived small RNAs, shown to be strongly induced during an early phase of learning in mouse, is also expressed in man, and at least one representative (SNORD85) was strongly down-regulated in schizophrenia synaptosomes.
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Affiliation(s)
- Neil R. Smalheiser
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
| | - Giovanni Lugli
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Hui Zhang
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Hooriyah Rizavi
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Edwin H. Cook
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yogesh Dwivedi
- Department of Psychiatry and Psychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, United States of America
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26
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Wang H, Chung PJ, Liu J, Jang IC, Kean MJ, Xu J, Chua NH. Genome-wide identification of long noncoding natural antisense transcripts and their responses to light in Arabidopsis. Genome Res 2014; 24:444-53. [PMID: 24402519 PMCID: PMC3941109 DOI: 10.1101/gr.165555.113] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent research on long noncoding RNAs (lncRNAs) has expanded our understanding of gene transcription regulation and the generation of cellular complexity. Depending on their genomic origins, lncRNAs can be transcribed from intergenic or intragenic regions or from introns of protein-coding genes. We have recently reported more than 6000 intergenic lncRNAs in Arabidopsis. Here, we systematically identified long noncoding natural antisense transcripts (lncNATs), defined as lncRNAs transcribed from the opposite DNA strand of coding or noncoding genes. We found a total of 37,238 sense–antisense transcript pairs and 70% of annotated mRNAs to be associated with antisense transcripts in Arabidopsis. These lncNATs could be reproducibly detected by different technical platforms, including strand-specific tiling arrays, Agilent custom expression arrays, strand-specific RNA-seq, and qRT-PCR experiments. Moreover, we investigated the expression profiles of sense–antisense pairs in response to light and observed spatial and developmental-specific light effects on 626 concordant and 766 discordant NAT pairs. Genes for a large number of the light-responsive NAT pairs are associated with histone modification peaks, and histone acetylation is dynamically correlated with light-responsive expression changes of NATs.
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Affiliation(s)
- Huan Wang
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA
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27
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Burroughs AM, Ando Y, Aravind L. New perspectives on the diversification of the RNA interference system: insights from comparative genomics and small RNA sequencing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:141-81. [PMID: 24311560 DOI: 10.1002/wrna.1210] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/03/2013] [Accepted: 11/01/2013] [Indexed: 12/19/2022]
Abstract
Our understanding of the pervasive involvement of small RNAs in regulating diverse biological processes has been greatly augmented by recent application of deep-sequencing technologies to small RNA across diverse eukaryotes. We review the currently known small RNA classes and place them in context of the reconstructed evolutionary history of the RNA interference (RNAi) protein machinery. This synthesis indicates that the earliest versions of eukaryotic RNAi systems likely utilized small RNA processed from three types of precursors: (1) sense-antisense transcriptional products, (2) genome-encoded, imperfectly complementary hairpin sequences, and (3) larger noncoding RNA precursor sequences. Structural dissection of PIWI proteins along with recent discovery of novel families (including Med13 of the Mediator complex) suggest that emergence of a distinct architecture with the N-terminal domains (also occurring separately fused to endoDNases in prokaryotes) formed via duplication of an ancestral unit was key to their recruitment as primary RNAi effectors and use of small RNAs of certain preferred lengths. Prokaryotic PIWI proteins are typically components of several RNA-directed DNA restriction or CRISPR/Cas systems. However, eukaryotic versions appear to have emerged from a subset that evolved RNA-directed RNAi. They were recruited alongside RNaseIII domains and RNA-dependent RNA polymerase (RdRP) domains, also from prokaryotic systems, to form the core eukaryotic RNAi system. Like certain regulatory systems, RNAi diversified into two distinct but linked arms concomitant with eukaryotic nucleocytoplasmic compartmentalization. Subsequent elaboration of RNAi proceeded via diversification of the core protein machinery through lineage-specific expansions and recruitment of new components from prokaryotes (nucleases and small RNA-modifying enzymes), allowing for diversification of associating small RNAs.
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Affiliation(s)
- Alexander Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
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28
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Zheng LL, Wen YZ, Yang JH, Liao JY, Shao P, Xu H, Zhou H, Wen JZ, Lun ZR, Ayala FJ, Qu LH. Comparative transcriptome analysis of small noncoding RNAs in different stages of Trypanosoma brucei. RNA (NEW YORK, N.Y.) 2013; 19:863-875. [PMID: 23704326 PMCID: PMC3683921 DOI: 10.1261/rna.035683.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
Trypanosoma brucei, a pathogen of human and domestic animals, is an early evolved parasitic protozoan with a complex life cycle. Most genes of this parasite are post-transcriptionally regulated. However, the mechanisms and the molecules involved remain largely unknown. We have deep-sequenced the small RNAs of two life stages of this parasite--the bloodstream form and the procyclic form. Our results show that the small RNAs of T. brucei could derive from multiple sources, including NATs (natural antisense transcripts), tRNAs, and rRNAs. Most of these small RNAs in the two stages were found to share uniform characteristics. However, our results demonstrate that their variety and expression show significant differences between different stages, indicating possible functional differentiation. Dicer-knockdown evidence further proved that some of the small interfering RNAs (siRNAs) could regulate the expression of genes. Based on the genome-wide analysis of the small RNAs in the two stages of T. brucei, our results not only provide evidence to study their differentiation but also shed light on questions regarding the origins and evolution of small RNA-based mechanisms in early eukaryotes.
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MESH Headings
- Base Sequence
- Computational Biology
- Evolution, Molecular
- Gene Expression Profiling/methods
- Gene Expression Regulation
- Genes, Protozoan
- High-Throughput Nucleotide Sequencing
- Molecular Sequence Data
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribonuclease III/genetics
- Ribonuclease III/metabolism
- Trypanosoma brucei brucei/genetics
- Trypanosoma brucei brucei/metabolism
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Affiliation(s)
- Ling-Ling Zheng
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yan-Zi Wen
- Key Laboratory of Tropical Disease and Control, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jian-Hua Yang
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jian-You Liao
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Peng Shao
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hui Xu
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hui Zhou
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jun-Zhi Wen
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhao-Rong Lun
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
- Key Laboratory of Tropical Disease and Control, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
- Centre for Parasitology and Disease, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, United Kingdom
| | - Francisco J. Ayala
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
| | - Liang-Hu Qu
- State Key Laboratory of Biocontrol, Key Laboratory of Gene Engineering, Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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Zhang X, Lii Y, Wu Z, Polishko A, Zhang H, Chinnusamy V, Lonardi S, Zhu JK, Liu R, Jin H. Mechanisms of small RNA generation from cis-NATs in response to environmental and developmental cues. MOLECULAR PLANT 2013; 6:704-15. [PMID: 23505223 PMCID: PMC3660955 DOI: 10.1093/mp/sst051] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 02/28/2013] [Indexed: 05/18/2023]
Abstract
A large proportion of eukaryotic genomes is transcribed from both positive and negative strands of DNA and thus may generate overlapping sense and antisense transcripts. Some of these so-called natural antisense transcripts (NATs) are possibly co-regulated. When the overlapping sense and antisense transcripts are expressed at the same time in the same cell in response to various developmental and environmental cues; they may form double-stranded RNAs, which could be recognized by the small RNA biogenesis machinery and processed into small interfering RNAs (siRNAs). cis-NAT-derived siRNAs (nat-siRNAs) are present in plants, animals, and fungi. In plants, the presence of nat-siRNAs is supported not only by Northern blot and genetic analyses, but also by the fact that there is an overall sixfold enrichment of siRNAs in the overlapping regions of cis-NATs and 19%-29% of the siRNA-generating cis-NATs in plants give rise to siRNAs only in their overlapping regions. Silencing mediated by nat-siRNAs is one of the mechanisms for regulating the expression of the cis-NATs. This review focuses on challenging issues related to the biogenesis mechanisms as well as regulation and detection of nat-siRNAs. The advantages and limitations of new technologies for detecting cis-NATs, including direct RNA sequencing and strand-specific RNA sequencing, are also discussed.
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Affiliation(s)
- Xiaoming Zhang
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Yifan Lii
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Zhigang Wu
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Anton Polishko
- Computer Science and Engineering, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Huiming Zhang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
| | - Viswanathan Chinnusamy
- Division of Plant Physiology, Indian Agricultural Research Institute, New Delhi 110012, India
| | - Stefano Lonardi
- Computer Science and Engineering, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Jian-Kang Zhu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
- Shanghai Center for Plant Stress Biology and Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- To whom correspondence should be addressed. H.J. E-mail , tel. +1-951-827-7995. R.L. E-mail . J.-k.Z. E-mail
| | - Renyi Liu
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
- To whom correspondence should be addressed. H.J. E-mail , tel. +1-951-827-7995. R.L. E-mail . J.-k.Z. E-mail
| | - Hailing Jin
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology and Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
- To whom correspondence should be addressed. H.J. E-mail , tel. +1-951-827-7995. R.L. E-mail . J.-k.Z. E-mail
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30
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Mazières J, Catherinne C, Delfour O, Gouin S, Rouquette I, Delisle MB, Prévot G, Escamilla R, Didier A, Persing DH, Bates M, Michot B. Alternative processing of the U2 small nuclear RNA produces a 19-22nt fragment with relevance for the detection of non-small cell lung cancer in human serum. PLoS One 2013; 8:e60134. [PMID: 23527303 PMCID: PMC3603938 DOI: 10.1371/journal.pone.0060134] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 02/21/2013] [Indexed: 12/28/2022] Open
Abstract
RNU2 exists in two functional forms (RNU2-1 and RNU2-2) distinguishable by the presence of a unique 4-bases motif. Detailed investigation of datasets obtained from deep sequencing of five human lung primary tumors revealed that both forms express at a high rate a 19-22nt fragment (miR-U2-1 and -2) from its 3' region and contains the 4-bases motif. Deep sequencing of independent pools of serum samples from healthy donors and lung cancer patients revealed that miR-U2-1 and -2 are pervasively processed in lung tissue by means of endonucleolytic cleavages and stably exported to the blood. Then, microarrays hybridization experiments of matched normal/tumor samples revealed a significant over-expression of miR-U2-1 in 14 of 18 lung primary tumors. Subsequently, qRT-PCR of miR-U2-1 using serum from 62 lung cancer patients and 96 various controls demonstrated that its expression levels identify lung cancer patients with 79% sensitivity and 80% specificity. miR-U2-1 expression correlated with the presence or absence of lung cancer in patients with chronic obstructive pulmonary disease (COPD), other diseases of the lung - not cancer, and in healthy controls. These data suggest that RNU2-1 is a new bi-functional ncRNA that produces a 19-22nt fragment which may be useful in detecting lung cancer non-invasively in high risk patients.
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Affiliation(s)
- Julien Mazières
- Service de Pneumologie, Hôpital Larrey, CHU de Toulouse, Université de Toulouse III (Paul Sabatier), Toulouse, France
| | | | | | - Sandrine Gouin
- Service de Pneumologie, Hôpital Larrey, CHU de Toulouse, Université de Toulouse III (Paul Sabatier), Toulouse, France
| | - Isabelle Rouquette
- Service d'anatomie pathologique, Hôpital Rangueil, CHU de Toulouse, Toulouse, France
| | | | - Grégoire Prévot
- Service de Pneumologie, Hôpital Larrey, CHU de Toulouse, Université de Toulouse III (Paul Sabatier), Toulouse, France
| | - Roger Escamilla
- Service de Pneumologie, Hôpital Larrey, CHU de Toulouse, Université de Toulouse III (Paul Sabatier), Toulouse, France
| | - Alain Didier
- Service de Pneumologie, Hôpital Larrey, CHU de Toulouse, Université de Toulouse III (Paul Sabatier), Toulouse, France
| | | | - Mike Bates
- Cepheid USA, Sunnyvale, California, United States of America
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31
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Bray PF, McKenzie SE, Edelstein LC, Nagalla S, Delgrosso K, Ertel A, Kupper J, Jing Y, Londin E, Loher P, Chen HW, Fortina P, Rigoutsos I. The complex transcriptional landscape of the anucleate human platelet. BMC Genomics 2013; 14:1. [PMID: 23323973 PMCID: PMC3722126 DOI: 10.1186/1471-2164-14-1] [Citation(s) in RCA: 341] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 12/05/2012] [Indexed: 12/11/2022] Open
Abstract
Background Human blood platelets are essential to maintaining normal hemostasis, and platelet dysfunction often causes bleeding or thrombosis. Estimates of genome-wide platelet RNA expression using microarrays have provided insights to the platelet transcriptome but were limited by the number of known transcripts. The goal of this effort was to deep-sequence RNA from leukocyte-depleted platelets to capture the complex profile of all expressed transcripts. Results From each of four healthy individuals we generated long RNA (≥40 nucleotides) profiles from total and ribosomal-RNA depleted RNA preparations, as well as short RNA (<40 nucleotides) profiles. Analysis of ~1 billion reads revealed that coding and non-coding platelet transcripts span a very wide dynamic range (≥16 PCR cycles beyond β-actin), a result we validated through qRT-PCR on many dozens of platelet messenger RNAs. Surprisingly, ribosomal-RNA depletion significantly and adversely affected estimates of the relative abundance of transcripts. Of the known protein-coding loci, ~9,500 are present in human platelets. We observed a strong correlation between mRNAs identified by RNA-seq and microarray for well-expressed mRNAs, but RNASeq identified many more transcripts of lower abundance and permitted discovery of novel transcripts. Conclusions Our analyses revealed diverse classes of non-coding RNAs, including: pervasive antisense transcripts to protein-coding loci; numerous, previously unreported and abundant microRNAs; retrotransposons; and thousands of novel un-annotated long and short intronic transcripts, an intriguing finding considering the anucleate nature of platelets. The data are available through a local mirror of the UCSC genome browser and can be accessed at:
http://cm.jefferson.edu/platelets_2012/.
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Affiliation(s)
- Paul F Bray
- Cardeza Foundation for Hematologic Research, Division of Hematology, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
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Chalupnikova K, Nejepinska J, Svoboda P. Production and application of long dsRNA in mammalian cells. Methods Mol Biol 2013; 942:291-314. [PMID: 23027058 DOI: 10.1007/978-1-62703-119-6_16] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Double-stranded RNA (dsRNA) is involved in different biological processes. At least three different pathways can respond to dsRNA in mammals. One of these pathways is RNA interference (RNAi) where long dsRNA induces sequence-specific degradation of transcripts carrying sequences complementary to dsRNA. Long dsRNA is also a potent trigger of the interferon pathway, a sequence-independent response that leads to global suppression of translation and global RNA degradation. In addition, dsRNA can be edited by adenosine deamination, which may result in nuclear retention and degradation of dsRNA or in alteration of RNA coding potential. Here, we provide a technical review summarizing different strategies of long dsRNA usage. While the review is largely focused on long dsRNA-induced RNAi in mammalian cells, it also provides helpful information on both the in vitro production and in vivo expression of dsRNAs. We present an overview of currently available vectors for dsRNA expression and provide the latest update on oocyte-specific transgenic RNAi approaches.
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Polikepahad S, Corry DB. Profiling of T helper cell-derived small RNAs reveals unique antisense transcripts and differential association of miRNAs with argonaute proteins 1 and 2. Nucleic Acids Res 2013; 41:1164-77. [PMID: 23185045 PMCID: PMC3553939 DOI: 10.1093/nar/gks1098] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 10/15/2012] [Accepted: 10/21/2012] [Indexed: 01/20/2023] Open
Abstract
RNA interference mediated through antisense transcripts is a fundamentally important mechanism regulating gene expression that remains incompletely understood. Here, we have used next-generation sequencing to determine from mouse CD4+ T cells the functional implications of antisense transcripts binding to argonaute (AGO) proteins that mediate RNA interference and post-transcriptional gene silencing. This effort identified 90 new microRNAs (miRNAs) and six endogenous hairpin RNA-derived small interfering RNAs (siRNAs) mapping to distinct introns. Unexpectedly, 69 miRNAs were expressed as non-canonical isomiRs as the dominant AGO-binding transcript, with extensive 3' terminal nucleotide modifications. Furthermore, differential expression analysis between AGO1- and AGO2-bound miRNAs suggested preferential binding of isomiRs ending with 3' adenine residues to AGO1 and 3' uridine residues to AGO2. Analysis of the putative targets of all miRNAs suggested a striking preference for regulating transcription and transcription factors with additional evidence of a functional division of labor between AGO proteins in this regard. We further provide evidence that multiple mitochondrial genomic loci serve as the source of endogenous cis-natural antisense transcripts. These findings imply diversity in AGO protein function based on differential miRNA binding and indicate that RNA interference-based gene regulation is more complex than previously recognized.
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Affiliation(s)
- Sumanth Polikepahad
- Department of Medicine and Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - David B. Corry
- Department of Medicine and Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
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Zhang X, Xia J, Lii YE, Barrera-Figueroa BE, Zhou X, Gao S, Lu L, Niu D, Chen Z, Leung C, Wong T, Zhang H, Guo J, Li Y, Liu R, Liang W, Zhu JK, Zhang W, Jin H. Genome-wide analysis of plant nat-siRNAs reveals insights into their distribution, biogenesis and function. Genome Biol 2012; 13:R20. [PMID: 22439910 PMCID: PMC3439971 DOI: 10.1186/gb-2012-13-3-r20] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 03/15/2012] [Accepted: 03/22/2012] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Many eukaryotic genomes encode cis-natural antisense transcripts (cis-NATs). Sense and antisense transcripts may form double-stranded RNAs that are processed by the RNA interference machinery into small interfering RNAs (siRNAs). A few so-called nat-siRNAs have been reported in plants, mammals, Drosophila, and yeasts. However, many questions remain regarding the features and biogenesis of nat-siRNAs. RESULTS Through deep sequencing, we identified more than 17,000 unique siRNAs corresponding to cis-NATs from biotic and abiotic stress-challenged Arabidopsis thaliana and 56,000 from abiotic stress-treated rice. These siRNAs were enriched in the overlapping regions of NATs and exhibited either site-specific or distributed patterns, often with strand bias. Out of 1,439 and 767 cis-NAT pairs identified in Arabidopsis and rice, respectively, 84 and 119 could generate at least 10 siRNAs per million reads from the overlapping regions. Among them, 16 cis-NAT pairs from Arabidopsis and 34 from rice gave rise to nat-siRNAs exclusively in the overlap regions. Genetic analysis showed that the overlapping double-stranded RNAs could be processed by Dicer-like 1 (DCL1) and/or DCL3. The DCL3-dependent nat-siRNAs were also dependent on RNA-dependent RNA polymerase 2 (RDR2) and plant-specific RNA polymerase IV (PolIV), whereas only a fraction of DCL1-dependent nat-siRNAs was RDR- and PolIV-dependent. Furthermore, the levels of some nat-siRNAs were regulated by specific biotic or abiotic stress conditions in Arabidopsis and rice. CONCLUSIONS Our results suggest that nat-siRNAs display distinct distribution patterns and are generated by DCL1 and/or DCL3. Our analysis further supported the existence of nat-siRNAs in plants and advanced our understanding of their characteristics.
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Affiliation(s)
- Xiaoming Zhang
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology, University of California, Riverside, CA 92521, USA
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Abstract
While most gene transcription yields RNA transcripts that code for proteins, a sizable proportion of the genome generates RNA transcripts that do not code for proteins, but may have important regulatory functions. The brain-derived neurotrophic factor (BDNF) gene, a key regulator of neuronal activity, is overlapped by a primate-specific, antisense long noncoding RNA (lncRNA) called BDNFOS. We demonstrate reciprocal patterns of BDNF and BDNFOS transcription in highly active regions of human neocortex removed as a treatment for intractable seizures. A genome-wide analysis of activity-dependent coding and noncoding human transcription using a custom lncRNA microarray identified 1288 differentially expressed lncRNAs, of which 26 had expression profiles that matched activity-dependent coding genes and an additional 8 were adjacent to or overlapping with differentially expressed protein-coding genes. The functions of most of these protein-coding partner genes, such as ARC, include long-term potentiation, synaptic activity, and memory. The nuclear lncRNAs NEAT1, MALAT1, and RPPH1, composing an RNAse P-dependent lncRNA-maturation pathway, were also upregulated. As a means to replicate human neuronal activity, repeated depolarization of SY5Y cells resulted in sustained CREB activation and produced an inverse pattern of BDNF-BDNFOS co-expression that was not achieved with a single depolarization. RNAi-mediated knockdown of BDNFOS in human SY5Y cells increased BDNF expression, suggesting that BDNFOS directly downregulates BDNF. Temporal expression patterns of other lncRNA-messenger RNA pairs validated the effect of chronic neuronal activity on the transcriptome and implied various lncRNA regulatory mechanisms. lncRNAs, some of which are unique to primates, thus appear to have potentially important regulatory roles in activity-dependent human brain plasticity.
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36
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Li Z, Ender C, Meister G, Moore PS, Chang Y, John B. Extensive terminal and asymmetric processing of small RNAs from rRNAs, snoRNAs, snRNAs, and tRNAs. Nucleic Acids Res 2012; 40:6787-99. [PMID: 22492706 PMCID: PMC3413118 DOI: 10.1093/nar/gks307] [Citation(s) in RCA: 239] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 03/22/2012] [Indexed: 01/09/2023] Open
Abstract
Deep sequencing studies frequently identify small RNA fragments of abundant RNAs. These fragments are thought to represent degradation products of their precursors. Using sequencing, computational analysis, and sensitive northern blot assays, we show that constitutively expressed non-coding RNAs such as tRNAs, snoRNAs, rRNAs and snRNAs preferentially produce small 5' and 3' end fragments. Similar to that of microRNA processing, these terminal fragments are generated in an asymmetric manner that predominantly favors either the 5' or 3' end. Terminal-specific and asymmetric processing of these small RNAs occurs in both mouse and human cells. In addition to the known processing of some 3' terminal tRNA-derived fragments (tRFs) by the RNase III endonuclease Dicer, we show that several RNase family members can produce tRFs, including Angiogenin that cleaves the TψC loop to generate 3' tRFs. The 3' terminal tRFs but not the 5' tRFs are highly complementary to human endogenous retroviral sequences in the genome. Despite their independence from Dicer processing, these tRFs associate with Ago2 and are capable of down regulating target genes by transcript cleavage in vitro. We suggest that endogenous 3' tRFs have a role in regulating the unwarranted expression of endogenous viruses through the RNA interference pathway.
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MESH Headings
- Animals
- Argonaute Proteins/metabolism
- Endogenous Retroviruses/genetics
- Humans
- Mice
- Proteins/physiology
- RNA Cleavage
- RNA Processing, Post-Transcriptional
- RNA, Messenger/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/metabolism
- RNA, Small Nuclear/chemistry
- RNA, Small Nuclear/metabolism
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/metabolism
- RNA, Small Untranslated/chemistry
- RNA, Small Untranslated/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/metabolism
- RNA-Binding Proteins
- Ribonuclease III/physiology
- Ribonuclease, Pancreatic/metabolism
- Ribonucleases/metabolism
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Affiliation(s)
- Zhihua Li
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Christine Ender
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Gunter Meister
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Patrick S. Moore
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Yuan Chang
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Bino John
- School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, Cancer Virology Program, Hillman Cancer Center, 5117 Centre Avenue, Pittsburgh, PA 15213, USA and Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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37
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Emerging roles of non-coding RNAs in brain evolution, development, plasticity and disease. Nat Rev Neurosci 2012; 13:528-41. [PMID: 22814587 DOI: 10.1038/nrn3234] [Citation(s) in RCA: 420] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Novel classes of small and long non-coding RNAs (ncRNAs) are being characterized at a rapid pace, driven by recent paradigm shifts in our understanding of genomic architecture, regulation and transcriptional output, as well as by innovations in sequencing technologies and computational and systems biology. These ncRNAs can interact with DNA, RNA and protein molecules; engage in diverse structural, functional and regulatory activities; and have roles in nuclear organization and transcriptional, post-transcriptional and epigenetic processes. This expanding inventory of ncRNAs is implicated in mediating a broad spectrum of processes including brain evolution, development, synaptic plasticity and disease pathogenesis.
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38
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Spadaro PA, Bredy TW. Emerging role of non-coding RNA in neural plasticity, cognitive function, and neuropsychiatric disorders. Front Genet 2012; 3:132. [PMID: 22811697 PMCID: PMC3395882 DOI: 10.3389/fgene.2012.00132] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/28/2012] [Indexed: 11/18/2022] Open
Abstract
Non-coding RNAs (ncRNAs) have emerged as critical regulators of transcription, epigenetic processes, and gene silencing, which make them ideal candidates for insight into molecular evolution and a better understanding of the molecular pathways of neuropsychiatric disease. Here, we provide an overview of the current state of knowledge regarding various classes of ncRNAs and their role in neural plasticity and cognitive function, and highlight the potential contribution they may make to the development of a variety of neuropsychiatric disorders, including schizophrenia, addiction, and fear-related anxiety disorders.
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Affiliation(s)
- Paola A Spadaro
- Psychiatric Epigenomics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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Abstract
Although the term 'epigenetics' was coined nearly seventy years ago, its critical function in memory processing by the adult CNS has only recently been appreciated. The hypothesis that epigenetic mechanisms regulate memory and behavior was motivated by the need for stable molecular processes that evade turnover of the neuronal proteome. In this article, we discuss evidence that supports a role for neural epigenetic modifications in the formation, consolidation and storage of memory. In addition, we will review the evidence that epigenetic mechanisms regulate synaptic plasticity, a cellular correlate of memory. We will also examine how the concerted action of multiple epigenetic mechanisms with varying spatiotemporal profiles influence selective gene expression in response to behavioral experience. Finally, we will suggest key areas for future research that will help elucidate the complex, vital and still mysterious, role of epigenetic mechanisms in neural function and behavior.
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Affiliation(s)
- Faraz A Sultan
- Department of Neurobiology, University of Alabama at Birmingham, Evelyn F McKnight Brain Institute, 1007 Shelby Building, 1825 University Boulevard Birmingham, AL 35294-2182, USA
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40
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Abstract
The importance of various classes of regulatory non-protein-coding RNA molecules (ncRNAs) in the normal functioning of the CNS is becoming increasingly evident. ncRNAs are involved in neuronal cell specification and patterning during development, but also in higher cognitive processes, such as structural plasticity and memory formation in the adult brain. We discuss advances in understanding of the function of ncRNAs in the CNS, with a focus on the potential involvement of specific species, such as microRNAs, endogenous small interfering RNAs, long intergenic non-coding RNAs, and natural antisense transcripts, in various neurodegenerative disorders. This emerging field is anticipated to profoundly affect clinical research, diagnosis, and therapy in neurology.
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41
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Schouten M, Buijink MR, Lucassen PJ, Fitzsimons CP. New Neurons in Aging Brains: Molecular Control by Small Non-Coding RNAs. Front Neurosci 2012; 6:25. [PMID: 22363255 PMCID: PMC3281214 DOI: 10.3389/fnins.2012.00025] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 01/30/2012] [Indexed: 12/12/2022] Open
Abstract
Adult neurogenesis generates functional neurons from neural stem cells present in specific brain regions. It is largely confined to two main regions: the subventricular zone of the lateral ventricle, and the subgranular zone of the dentate gyrus (DG), in the hippocampus. With age, the function of the hippocampus and particularly the DG is impaired. For instance, adult neurogenesis is decreased with aging, in both proliferating and differentiation of newborn cells, while in parallel an age-associated decline in cognitive performance is often seen. Surprisingly, the synaptogenic potential of adult-born neurons is only marginally influenced by aging. Therefore, although proliferation, differentiation, and synaptogenesis of adult-born new neurons in the DG are closely related to each other, they are differentially affected by aging. In this review we discuss the crucial roles of a novel class of recently discovered modulators of gene expression, the small non-coding RNAs, in the regulation of adult neurogenesis. Multiple small non-coding RNAs are differentially expressed in the hippocampus. In particular a subgroup of the small non-coding RNAs, the microRNAs, fine-tune the progression of adult neurogenesis. This makes small non-coding RNAs appealing candidates to orchestrate the functional alterations in adult neurogenesis and cognition associated with aging. Finally, we summarize observations that link changes in circulating levels of steroid hormones with alterations in adult neurogenesis, cognitive decline, and vulnerability to psychopathology in advanced age, and discuss a potential interplay between steroid hormone receptors and microRNAs in cognitive decline in aging individuals.
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Affiliation(s)
- Marijn Schouten
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
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42
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Frías-Lasserre D. Non coding RNAs and viruses in the framework of the phylogeny of the genes, epigenesis and heredity. Int J Mol Sci 2012; 13:477-490. [PMID: 22312265 PMCID: PMC3269699 DOI: 10.3390/ijms13010477] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 01/21/2023] Open
Abstract
The origin of genes is one of the most enigmatic events in the origin of life. It has been suggested that noncoding (nc) RNA was probably a precursor in the formation of the first polypeptide, and also at the origin of the first manifestation of life and genes. ncRNAs are also becoming central for understanding gene expression and silencing. Indeed, before the discovery of ncRNAs, proteins were viewed as the major molecules in the regulation of gene expression and gene silencing; however, recent findings suggest that ncRNA also plays an important role in gene expression. Reverse transcription of RNA viruses and their integration into the genome of eukaryotes and also their relationship with the ncRNA suggest that their origin is basal in genome evolution, and also probably constitute the first mechanism of gene regulation. I am to review the different roles of ncRNAs in the framework of gene evolution, as well as the importance of ncRNAs and viruses in the epigenesis and in the non-Mendelian model of heredity and evolution.
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Affiliation(s)
- Daniel Frías-Lasserre
- Institute of Entomology, Metropolitan University of Educational Sciences, Avenue J.P. Alessandri 774 Ñuñoa, Código Postal 7760197, Santiago, Chile; E-Mail: ; Tel.: +56-2-2412457; Fax: +56-2-2412699
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Burroughs AM, Kawano M, Ando Y, Daub CO, Hayashizaki Y. pre-miRNA profiles obtained through application of locked nucleic acids and deep sequencing reveals complex 5'/3' arm variation including concomitant cleavage and polyuridylation patterns. Nucleic Acids Res 2011; 40:1424-37. [PMID: 22058130 PMCID: PMC3287202 DOI: 10.1093/nar/gkr903] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Recent research hints at an underappreciated complexity in pre-miRNA processing and regulation. Global profiling of pre-miRNA and its potential to increase understanding of the pre-miRNA landscape is impeded by overlap with highly expressed classes of other non coding (nc) RNA. Here, we present a data set excluding these RNA before sequencing through locked nucleic acids (LNA), greatly increasing pre-miRNA sequence counts with no discernable effect on pre-miRNA or mature miRNA sequencing. Analysis of profiles generated in total, nuclear and cytoplasmic cell fractions reveals that pre-miRNAs are subject to a wide range of regulatory processes involving loci-specific 3′- and 5′-end variation entailing complex cleavage patterns with co-occurring polyuridylation. Additionally, examination of nuclear-enriched flanking sequences of pre-miRNA, particularly those derived from polycistronic miRNA transcripts, provides insight into miRNA and miRNA-offset (moRNA) production, specifically identifying novel classes of RNA potentially functioning as moRNA precursors. Our findings point to particularly intricate regulation of the let-7 family in many ways reminiscent of DICER1-independent, pre-mir-451-like processing, introduce novel and unify known forms of pre-miRNA regulation and processing, and shed new light on overlooked products of miRNA processing pathways.
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Affiliation(s)
- A Maxwell Burroughs
- Omics Science Center, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa 230-0045, Japan.
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Smalheiser NR. The search for endogenous siRNAs in the mammalian brain. Exp Neurol 2011; 235:455-63. [PMID: 22062046 DOI: 10.1016/j.expneurol.2011.10.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/28/2011] [Accepted: 10/17/2011] [Indexed: 02/08/2023]
Abstract
A decade ago, RNA interference was proposed to serve as a physiologic means of regulating long-term gene expression in the mammalian brain. However, during the intervening years, this hypothesis appeared to be contradicted by both experimental data and theoretical considerations. More recently, the advent of deep sequencing technology has permitted a re-assessment of this issue. As reviewed here, a large population of small RNAs having features characteristic of endogenous siRNAs are detected within adult mouse hippocampus, which derive from genes involved in synaptic structure and signaling, and which show a significant, though modest (16-22%) up-regulation during olfactory discrimination training. Small RNAs derived from abundant cellular noncoding RNAs are also detected; in particular, a subpopulation of RNAs 25-30 nt. in length shows very large (>100 fold) up-regulation during olfactory discrimination training. Preliminary data suggest that the 25-30 nt. RNAs may associate with MIWI rather than Argonaute 1-4 homologues. I conclude that, despite their apparent low abundance, endogenous siRNAs and noncoding RNA-derived small RNAs are likely to play an important role in regulating synaptic plasticity.
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Affiliation(s)
- Neil R Smalheiser
- University of Illinois at Chicago, Psychiatric Institute MC912, Chicago, IL 60612, USA.
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Mitochondrial small RNAs that are up-regulated in hippocampus during olfactory discrimination training in mice. Mitochondrion 2011; 11:994-5. [PMID: 21925291 DOI: 10.1016/j.mito.2011.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/17/2011] [Accepted: 08/31/2011] [Indexed: 11/21/2022]
Abstract
Adult mice were trained to execute a nose-poke in a port containing one of two simultaneously present odors in order to obtain a reward. Hippocampus RNA of trained mice vs. controls was subjected to Illumina deep sequencing. Two mitochondrial RNAs (a tRNA and Mt-1) gave rise to 25-30-nt. small RNAs that showed a dramatic and specific increase with training (>50-fold relative to controls). Mt-1 is encoded within the termination association sequence (TAS) of the mitochondrial DNA control region. Small RNAs may link behavioral plasticity to protein synthesis and replication of mitochondria to support dendritic growth, spine stabilization, and synapse formation.
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Nejepinska J, Malik R, Filkowski J, Flemr M, Filipowicz W, Svoboda P. dsRNA expression in the mouse elicits RNAi in oocytes and low adenosine deamination in somatic cells. Nucleic Acids Res 2011; 40:399-413. [PMID: 21908396 PMCID: PMC3245926 DOI: 10.1093/nar/gkr702] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Double-stranded RNA (dsRNA) can enter different pathways in mammalian cells, including sequence-specific RNA interference (RNAi), sequence-independent interferon (IFN) response and editing by adenosine deaminases. To study the routing of dsRNA to these pathways in vivo, we used transgenic mice ubiquitously expressing from a strong promoter, an mRNA with a long hairpin in its 3′-UTR. The expressed dsRNA neither caused any developmental defects nor activated the IFN response, which was inducible only at high expression levels in cultured cells. The dsRNA was poorly processed into siRNAs in somatic cells, whereas, robust RNAi effects were found in oocytes, suggesting that somatic cells lack some factor(s) facilitating siRNA biogenesis. Expressed dsRNA did not cause transcriptional silencing in trans. Analysis of RNA editing revealed that a small fraction of long dsRNA is edited. RNA editing neither prevented the cytoplasmic localization nor processing into siRNAs. Thus, a long dsRNA structure is well tolerated in mammalian cells and is mainly causing a robust RNAi response in oocytes.
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Affiliation(s)
- Jana Nejepinska
- Institute of Molecular Genetics AS CR, Videnska 1083, 14220 Prague 4, Czech Republic
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Abstract
Eukaryotic genomes accommodate numerous types of information within diverse DNA and RNA sequence elements. At many loci, these elements overlap and the same sequence is read multiple times during the production, processing, localization, function and turnover of a single transcript. Moreover, two or more transcripts from the same locus might use a common sequence in different ways, to perform distinct biological roles. Recent results show that many transcripts also undergo post-transcriptional cleavage to release specific fragments, which can then function independently. This phenomenon appears remarkably widespread, with even well-documented transcript classes such as messenger RNAs yielding fragments. RNA fragmentation significantly expands the already extraordinary spectrum of transcripts present within eukaryotic cells, and also calls into question how the 'gene' should be defined.
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Scott MS, Ono M. From snoRNA to miRNA: Dual function regulatory non-coding RNAs. Biochimie 2011; 93:1987-92. [PMID: 21664409 PMCID: PMC3476530 DOI: 10.1016/j.biochi.2011.05.026] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/19/2011] [Indexed: 11/03/2022]
Abstract
Small nucleolar RNAs (snoRNAs) are an ancient class of small non-coding RNAs present in all eukaryotes and a subset of archaea that carry out a fundamental role in the modification and processing of ribosomal RNA. In recent years, however, a large proportion of snoRNAs have been found to be further processed into smaller molecules, some of which display different functionality. In parallel, several studies have uncovered extensive similarities between snoRNAs and other types of small non-coding RNAs, and in particular microRNAs. Here, we explore the extent of the relationship between these types of non-coding RNA and the possible underlying evolutionary forces that shaped this subset of the current non-coding RNA landscape.
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Affiliation(s)
- Michelle S Scott
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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Mattick JS. The central role of RNA in human development and cognition. FEBS Lett 2011; 585:1600-16. [DOI: 10.1016/j.febslet.2011.05.001] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 05/03/2011] [Indexed: 12/22/2022]
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