1
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Koffler-Brill T, Noy Y, Avraham KB. The long and short: Non-coding RNAs in the mammalian inner ear. Hear Res 2023; 428:108666. [PMID: 36566643 PMCID: PMC9883734 DOI: 10.1016/j.heares.2022.108666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 10/21/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Non-coding RNAs (ncRNAs) play a critical role in the entire body, and their mis-regulation is often associated with disease. In parallel with the advances in high-throughput sequencing technologies, there is a great deal of focus on this broad class of RNAs. Although these molecules are not translated into proteins, they are now well established as significant regulatory components in many biological pathways and pathological conditions. ncRNAs can be roughly divided into two main sub-groups based on the length of the transcript, with both the small and long non-coding RNAs having diverse regulatory functions. The smaller length group includes ribosomal RNAs (rRNA), transfer RNAs (tRNA), small nuclear RNAs (snRNA), small nucleolar RNAs (snoRNA), microRNAs (miRNA), small interfering RNAs (siRNA), and PIWI-associated RNAs (piRNA). The longer length group includes linear long non-coding RNAs (lncRNA) and circular RNAs (circRNA). This review is designed to present the different classes of small and long ncRNA molecules and describe some of their known roles in physiological and pathological conditions, as well as methods used to assess the validity and function of miRNAs and lncRNAs, with a focus on their role and functions in the inner ear, hearing and deafness.
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Affiliation(s)
- Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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2
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Abstract
Current estimates suggest that nearly half a billion people worldwide are affected by hearing loss. Because of the major psychological, social, economic, and health ramifications, considerable efforts have been invested in identifying the genes and molecular pathways involved in hearing loss, whether genetic or environmental, to promote prevention, improve rehabilitation, and develop therapeutics. Genomic sequencing technologies have led to the discovery of genes associated with hearing loss. Studies of the transcriptome and epigenome of the inner ear have characterized key regulators and pathways involved in the development of the inner ear and have paved the way for their use in regenerative medicine. In parallel, the immense preclinical success of using viral vectors for gene delivery in animal models of hearing loss has motivated the industry to work on translating such approaches into the clinic. Here, we review the recent advances in the genomics of auditory function and dysfunction, from patient diagnostics to epigenetics and gene therapy.
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Affiliation(s)
- Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; ,
| | - Kathleen Gwilliam
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
| | - Ronna Hertzano
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; ,
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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3
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Avraham KB, Khalaily L, Noy Y, Kamal L, Koffler-Brill T, Taiber S. The noncoding genome and hearing loss. Hum Genet 2022; 141:323-333. [PMID: 34491412 DOI: 10.1007/s00439-021-02359-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/29/2021] [Indexed: 12/16/2022]
Abstract
The age of sequencing has provided unprecedented insights into the human genome. The coding region of the genome comprises nearly 20,000 genes, of which approximately 4000 are associated with human disease. Beyond the protein-coding genome, which accounts for only 3% of the genome, lies a vast pool of regulatory elements in the form of promoters, enhancers, RNA species, and other intricate elements. These features undoubtably influence human health and disease, and as a result, a great deal of effort is currently being invested in deciphering their identity and mechanism. While a paucity of material has caused a lag in identifying these elements in the inner ear, the emergence of technologies for dealing with a minimal number of cells now has the field working overtime to catch up. Studies on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), methylation, histone modifications, and more are ongoing. A number of microRNAs and other noncoding elements are known to be associated with hearing impairment and there is promise that regulatory elements will serve as future tools and targets of therapeutics and diagnostics. This review covers the current state of the field and considers future directions for the noncoding genome and implications for hearing loss.
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Affiliation(s)
- Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel.
| | - Lama Khalaily
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Lara Kamal
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
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4
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Koffler-Brill T, Taiber S, Anaya A, Bordeynik-Cohen M, Rosen E, Kolla L, Messika-Gold N, Elkon R, Kelley MW, Ulitsky I, Avraham KB. Identification and characterization of key long non-coding RNAs in the mouse cochlea. RNA Biol 2020; 18:1160-1169. [PMID: 33131415 DOI: 10.1080/15476286.2020.1836456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The auditory system is a complex sensory network with an orchestrated multilayer regulatory programme governing its development and maintenance. Accumulating evidence has implicated long non-coding RNAs (lncRNAs) as important regulators in numerous systems, as well as in pathological pathways. However, their function in the auditory system has yet to be explored. Using a set of specific criteria, we selected four lncRNAs expressed in the mouse cochlea, which are conserved in the human transcriptome and are relevant for inner ear function. Bioinformatic characterization demonstrated a lack of coding potential and an absence of evolutionary conservation that represent properties commonly shared by their class members. RNAscope® analysis of the spatial and temporal expression profiles revealed specific localization to inner ear cells. Sub-cellular localization analysis presented a distinct pattern for each lncRNA and mouse tissue expression evaluation displayed a large variability in terms of level and location. Our findings establish the expression of specific lncRNAs in different cell types of the auditory system and present a potential pathway by which the lncRNA Gas5 acts in the inner ear. Studying lncRNAs and deciphering their functions may deepen our knowledge of inner ear physiology and morphology and may reveal the basis of as yet unresolved genetic hearing loss-related pathologies. Moreover, our experimental design may be employed as a reference for studying other inner ear-related lncRNAs, as well as lncRNAs expressed in other sensory systems.
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Affiliation(s)
- Tal Koffler-Brill
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Alejandro Anaya
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Mor Bordeynik-Cohen
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Einat Rosen
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Likhitha Kolla
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Naama Messika-Gold
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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5
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George MR, Duan Q, Nagle A, Kathiriya IS, Huang Y, Rao K, Haldar SM, Bruneau BG. Minimal in vivo requirements for developmentally regulated cardiac long intergenic non-coding RNAs. Development 2019; 146:dev.185314. [PMID: 31784461 DOI: 10.1242/dev.185314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/20/2019] [Indexed: 12/30/2022]
Abstract
Long intergenic non-coding RNAs (lincRNAs) have been implicated in gene regulation, but their requirement for development needs empirical interrogation. We computationally identified nine murine lincRNAs that have developmentally regulated transcriptional and epigenomic profiles specific to early heart differentiation. Six of the nine lincRNAs had in vivo expression patterns supporting a potential function in heart development, including a transcript downstream of the cardiac transcription factor Hand2, which we named Handlr (Hand2-associated lincRNA), Rubie and Atcayos We genetically ablated these six lincRNAs in mouse, which suggested genomic regulatory roles for four of the cohort. However, none of the lincRNA deletions led to severe cardiac phenotypes. Thus, we stressed the hearts of adult Handlr and Atcayos mutant mice by transverse aortic banding and found that absence of these lincRNAs did not affect cardiac hypertrophy or left ventricular function post-stress. Our results support roles for lincRNA transcripts and/or transcription in the regulation of topologically associated genes. However, the individual importance of developmentally specific lincRNAs is yet to be established. Their status as either gene-like entities or epigenetic components of the nucleus should be further considered.
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Affiliation(s)
- Matthew R George
- Gladstone Institutes, San Francisco, CA 94158, USA.,Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA.,Program in Developmental and Stem Cell Biology, University of California, San Francisco, CA 94143, USA
| | - Qiming Duan
- Gladstone Institutes, San Francisco, CA 94158, USA
| | | | - Irfan S Kathiriya
- Gladstone Institutes, San Francisco, CA 94158, USA.,Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA.,Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA 94158, USA
| | - Yu Huang
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Kavitha Rao
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Saptarsi M Haldar
- Gladstone Institutes, San Francisco, CA 94158, USA.,Division of Cardiology, Department of Medicine, University of California, San Francisco, CA 94143, USA.,Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - Benoit G Bruneau
- Gladstone Institutes, San Francisco, CA 94158, USA .,Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA.,Program in Developmental and Stem Cell Biology, University of California, San Francisco, CA 94143, USA.,Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.,Department of Pediatrics, University of California, San Francisco, CA 94143, USA
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6
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Genome-wide identification and characterization of long non-coding RNAs expressed during sheep fetal and postnatal hair follicle development. Sci Rep 2019; 9:8501. [PMID: 31186438 PMCID: PMC6559957 DOI: 10.1038/s41598-019-44600-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 05/03/2019] [Indexed: 01/09/2023] Open
Abstract
Long non-coding RNAs (lncRNAs), >200 nt in length, are transcribed from mammalian genomes. They play important regulatory roles in various biological processes; However, the function and expression profile of lncRNAs involved in the development of hair follicles in the fetus, have been relatively under-explored area. To investigate the specific role of lncRNAs and mRNAs that regulate hair follicle development, we herein performed a comprehensive study on the lncRNA and mRNA expression profiles of sheep at multiple embryonic days (E65, E85, E105, and E135) and six lambs aged one week (D7) and one month (D30) using RNA-seq technology. The number of genes (471 lncRNAs and 12,812 mRNAs) differentially expressed and potential targets of differentially expressed lncRNAs were predicted. Differentially expressed lncRNAs were grouped into 10 clusters based on their expression pattern by K-means clustering. Moreover, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that some differentially expressed mRNAs, such as DKK1, DSG4, FOXE1, Hoxc13, SFRP1, SFRP2, and Wnt10A overlapped with lncRNAs targets, and enriched in important hair follicle developmental pathways, including Wnt, TNF, and MAPK signaling pathways. In addition, 9 differentially expressed lncRNAs and 4 differentially expressed mRNAs were validated using quantitative real-time PCR (qRT-PCR). This study helps enrich the Ovis lncRNA databases and provides a comprehensive lncRNA transcriptome profile of fetal and postnatal skin of sheep. Additionally, it provides a foundation for further experiments on the role of lncRNAs in the regulation of hair growth in sheep.
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7
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Gagnier L, Belancio VP, Mager DL. Mouse germ line mutations due to retrotransposon insertions. Mob DNA 2019; 10:15. [PMID: 31011371 PMCID: PMC6466679 DOI: 10.1186/s13100-019-0157-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/01/2019] [Indexed: 12/24/2022] Open
Abstract
Transposable element (TE) insertions are responsible for a significant fraction of spontaneous germ line mutations reported in inbred mouse strains. This major contribution of TEs to the mutational landscape in mouse contrasts with the situation in human, where their relative contribution as germ line insertional mutagens is much lower. In this focussed review, we provide comprehensive lists of TE-induced mouse mutations, discuss the different TE types involved in these insertional mutations and elaborate on particularly interesting cases. We also discuss differences and similarities between the mutational role of TEs in mice and humans.
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Affiliation(s)
- Liane Gagnier
- Terry Fox Laboratory, BC Cancer and Department of Medical Genetics, University of British Columbia, V5Z1L3, Vancouver, BC Canada
| | - Victoria P. Belancio
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Dixie L. Mager
- Terry Fox Laboratory, BC Cancer and Department of Medical Genetics, University of British Columbia, V5Z1L3, Vancouver, BC Canada
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8
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Ushakov K, Koffler-Brill T, Rom A, Perl K, Ulitsky I, Avraham KB. Genome-wide identification and expression profiling of long non-coding RNAs in auditory and vestibular systems. Sci Rep 2017; 7:8637. [PMID: 28819115 PMCID: PMC5561060 DOI: 10.1038/s41598-017-08320-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 07/07/2017] [Indexed: 11/09/2022] Open
Abstract
Mammalian genomes encode multiple layers of regulation, including a class of RNA molecules known as long non-coding RNAs (lncRNAs). These are >200 nucleotides in length and similar to mRNAs, they are capped, polyadenylated, and spliced. In contrast to mRNAs, lncRNAs are less abundant and have higher tissue specificity, and have been linked to development, epigenetic processes, and disease. However, little is known about lncRNA function in the auditory and vestibular systems, or how they play a role in deafness and vestibular dysfunction. To help address this need, we performed a whole-genome identification of lncRNAs using RNA-seq at two developmental stages of the mouse inner ear sensory epithelium of the cochlea and vestibule. We identified 3,239 lncRNA genes, most of which were intergenic (lincRNAs) and 721 are novel. We examined temporal and tissue specificity by analyzing the developmental profiles on embryonic day 16.5 and at birth. The spatial and temporal patterns of three lncRNAs, two of which are in proximity to genes associated with hearing and deafness, were explored further. Our findings indicate that lncRNAs are prevalent in the sensory epithelium of the mouse inner ear and are likely to play key roles in regulating critical pathways for hearing and balance.
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Affiliation(s)
- Kathy Ushakov
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Aviv Rom
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Kobi Perl
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.,Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.
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9
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Wang M, Liu W, Jiao J, Li J, Wang C, Zhang L. Expression Profiling of mRNAs and Long Non-Coding RNAs in Aged Mouse Olfactory Bulb. Sci Rep 2017; 7:2079. [PMID: 28522862 PMCID: PMC5437011 DOI: 10.1038/s41598-017-02329-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/10/2017] [Indexed: 12/20/2022] Open
Abstract
Age-related decline in olfactory function affects the quality of life in elderly people and also potentially represents an early clinical symptom of neurodegenerative disorder. Olfactory bulb (OB) plays a central role in olfactory information transmitting and signal processing. The mechanisms underlying this impairment remain unclear. In the current study, microarray was used to investigate differentially expressed protein coding genes (PCGs) and long non-coding RNAs (lncRNAs) in OBs from three groups of mice of different ages (2 months-old young adults, 6 months-old mature adults and 20 months-old aged adults), for their potential roles in olfactory impairment. Gene Ontology and pathway analysis results showed that the differentially expressed PCGs in the OBs from aged mice were mainly associated with signal transduction, regulation of gene expression and cellular microenvironment. Similarly, gene set enrichment analysis identified two differentially and inversely expressed lncRNAs (NONMMUT004524 and NONMMUT000384), both of which were significantly associated with neuroactive ligand-receptor interaction pathway in the OBs of aged mice. These findings suggest that a decline of olfactory function in aged mice may be linked to differential expression of specific lncRNAs and their potentially adverse effects on the neuroactive ligand-receptor interaction pathway in the OB.
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Affiliation(s)
- Ming Wang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, 100005, China
| | - Wei Liu
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Jian Jiao
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, 100005, China
| | - Jingyun Li
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, 100005, China
| | - Chengshuo Wang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, 100005, China
| | - Luo Zhang
- Department of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China. .,Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, 100005, China. .,Department of Allergy, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China.
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10
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Doetzlhofer A, Avraham KB. Insights into inner ear-specific gene regulation: Epigenetics and non-coding RNAs in inner ear development and regeneration. Semin Cell Dev Biol 2017; 65:69-79. [PMID: 27836639 PMCID: PMC5512292 DOI: 10.1016/j.semcdb.2016.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/14/2016] [Accepted: 11/03/2016] [Indexed: 12/12/2022]
Abstract
The vertebrate inner ear houses highly specialized sensory organs, tuned to detect and encode sound, head motion and gravity. Gene expression programs under the control of transcription factors orchestrate the formation and specialization of the non-sensory inner ear labyrinth and its sensory constituents. More recently, epigenetic factors and non-coding RNAs emerged as an additional layer of gene regulation, both in inner ear development and disease. In this review, we provide an overview on how epigenetic modifications and non-coding RNAs, in particular microRNAs (miRNAs), influence gene expression and summarize recent discoveries that highlight their critical role in the proper formation of the inner ear labyrinth and its sensory organs. Finally, we discuss recent insights into how epigenetic factors and miRNAs may facilitate, or in the case of mammals, restrict inner ear sensory hair cell regeneration.
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Affiliation(s)
- Angelika Doetzlhofer
- The Solomon H. Snyder Department of Neuroscience, the Center for Sensory Biology, the Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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11
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Lineage tracing of Sox2-expressing progenitor cells in the mouse inner ear reveals a broad contribution to non-sensory tissues and insights into the origin of the organ of Corti. Dev Biol 2016; 414:72-84. [PMID: 27090805 DOI: 10.1016/j.ydbio.2016.03.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 03/09/2016] [Accepted: 03/26/2016] [Indexed: 11/22/2022]
Abstract
The transcription factor Sox2 is both necessary and sufficient for the generation of sensory regions of the inner ear. It regulates expression of the Notch ligand Jag1 in prosensory progenitors, which signal to neighboring cells to up-regulate Sox2 and sustain prosensory identity. However, the expression pattern of Sox2 in the early inner ear is very broad, suggesting that Sox2-expressing progenitors form a wide variety of cell types in addition to generating the sensory regions of the ear. We used Sox2-CreER mice to follow the fates of Sox2-expressing cells at different stages in ear development. We find that Sox2-expressing cells in the early otocyst give rise to large numbers of non-sensory structures throughout the inner ear, and that Sox2 only becomes a truly prosensory marker at embryonic day (E)11.5. Our fate map reveals the organ of Corti derives from a central domain on the medial side of the otocyst and shows that a significant amount of the organ of Corti derives from a Sox2-negative population in this region.
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12
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Schrauwen I, Hasin-Brumshtein Y, Corneveaux JJ, Ohmen J, White C, Allen AN, Lusis AJ, Van Camp G, Huentelman MJ, Friedman RA. A comprehensive catalogue of the coding and non-coding transcripts of the human inner ear. Hear Res 2015; 333:266-274. [PMID: 26341477 DOI: 10.1016/j.heares.2015.08.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 08/12/2015] [Accepted: 08/27/2015] [Indexed: 10/23/2022]
Abstract
The mammalian inner ear consists of the cochlea and the vestibular labyrinth (utricle, saccule, and semicircular canals), which participate in both hearing and balance. Proper development and life-long function of these structures involves a highly complex coordinated system of spatial and temporal gene expression. The characterization of the inner ear transcriptome is likely important for the functional study of auditory and vestibular components, yet, primarily due to tissue unavailability, detailed expression catalogues of the human inner ear remain largely incomplete. We report here, for the first time, comprehensive transcriptome characterization of the adult human cochlea, ampulla, saccule and utricle of the vestibule obtained from patients without hearing abnormalities. Using RNA-Seq, we measured the expression of >50,000 predicted genes corresponding to approximately 200,000 transcripts, in the adult inner ear and compared it to 32 other human tissues. First, we identified genes preferentially expressed in the inner ear, and unique either to the vestibule or cochlea. Next, we examined expression levels of specific groups of potentially interesting RNAs, such as genes implicated in hearing loss, long non-coding RNAs, pseudogenes and transcripts subject to nonsense mediated decay (NMD). We uncover the spatial specificity of expression of these RNAs in the hearing/balance system, and reveal evidence of tissue specific NMD. Lastly, we investigated the non-syndromic deafness loci to which no gene has been mapped, and narrow the list of potential candidates for each locus. These data represent the first high-resolution transcriptome catalogue of the adult human inner ear. A comprehensive identification of coding and non-coding RNAs in the inner ear will enable pathways of auditory and vestibular function to be further defined in the study of hearing and balance. Expression data are freely accessible at https://www.tgen.org/home/research/research-divisions/neurogenomics/supplementary-data/inner-ear-transcriptome.aspx.
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Affiliation(s)
- Isabelle Schrauwen
- Department of Medical Genetics, University of Antwerp, 2610 Antwerp, Belgium.,Neurogenomics Division and The Dorrance Center for Rare Childhood Disorders, Translational Genomics Research Institute, 85004 Phoenix, AZ
| | - Yehudit Hasin-Brumshtein
- Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Jason J Corneveaux
- Neurogenomics Division and The Dorrance Center for Rare Childhood Disorders, Translational Genomics Research Institute, 85004 Phoenix, AZ
| | - Jeffrey Ohmen
- House Ear Institute, Los Angeles 90057, CA, United States
| | - Cory White
- House Ear Institute, Los Angeles 90057, CA, United States.,Keck School of Medicine, USC, Los Angeles, CA, United States
| | - April N Allen
- Neurogenomics Division and The Dorrance Center for Rare Childhood Disorders, Translational Genomics Research Institute, 85004 Phoenix, AZ
| | - Aldons J Lusis
- Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Guy Van Camp
- Department of Medical Genetics, University of Antwerp, 2610 Antwerp, Belgium
| | - Matthew J Huentelman
- Neurogenomics Division and The Dorrance Center for Rare Childhood Disorders, Translational Genomics Research Institute, 85004 Phoenix, AZ
| | - Rick A Friedman
- Keck School of Medicine, USC, Los Angeles, CA, United States
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13
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Buchner DA, Nadeau JH. Contrasting genetic architectures in different mouse reference populations used for studying complex traits. Genome Res 2015; 25:775-91. [PMID: 25953951 PMCID: PMC4448675 DOI: 10.1101/gr.187450.114] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/31/2015] [Indexed: 01/14/2023]
Abstract
Quantitative trait loci (QTLs) are being used to study genetic networks, protein functions, and systems properties that underlie phenotypic variation and disease risk in humans, model organisms, agricultural species, and natural populations. The challenges are many, beginning with the seemingly simple tasks of mapping QTLs and identifying their underlying genetic determinants. Various specialized resources have been developed to study complex traits in many model organisms. In the mouse, remarkably different pictures of genetic architectures are emerging. Chromosome Substitution Strains (CSSs) reveal many QTLs, large phenotypic effects, pervasive epistasis, and readily identified genetic variants. In contrast, other resources as well as genome-wide association studies (GWAS) in humans and other species reveal genetic architectures dominated with a relatively modest number of QTLs that have small individual and combined phenotypic effects. These contrasting architectures are the result of intrinsic differences in the study designs underlying different resources. The CSSs examine context-dependent phenotypic effects independently among individual genotypes, whereas with GWAS and other mouse resources, the average effect of each QTL is assessed among many individuals with heterogeneous genetic backgrounds. We argue that variation of genetic architectures among individuals is as important as population averages. Each of these important resources has particular merits and specific applications for these individual and population perspectives. Collectively, these resources together with high-throughput genotyping, sequencing and genetic engineering technologies, and information repositories highlight the power of the mouse for genetic, functional, and systems studies of complex traits and disease models.
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Affiliation(s)
- David A Buchner
- Department of Genetics and Genome Sciences, Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Joseph H Nadeau
- Pacific Northwest Diabetes Research Institute, Seattle, Washington 98122, USA
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Ushakov K, Rudnicki A, Avraham KB. MicroRNAs in sensorineural diseases of the ear. Front Mol Neurosci 2013; 6:52. [PMID: 24391537 PMCID: PMC3870287 DOI: 10.3389/fnmol.2013.00052] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/04/2013] [Indexed: 12/30/2022] Open
Abstract
Non-coding microRNAs (miRNAs) have a fundamental role in gene regulation and expression in almost every multicellular organism. Only discovered in the last decade, miRNAs are already known to play a leading role in many aspects of disease. In the vertebrate inner ear, miRNAs are essential for controlling development and survival of hair cells. Moreover, dysregulation of miRNAs has been implicated in sensorineural hearing impairment, as well as in other ear diseases such as cholesteatomas, vestibular schwannomas, and otitis media. Due to the inaccessibility of the ear in humans, animal models have provided the optimal tools to study miRNA expression and function, in particular mice and zebrafish. A major focus of current research has been to discover the targets of the miRNAs expressed in the inner ear, in order to determine the regulatory pathways of the auditory and vestibular systems. The potential for miRNAs manipulation in development of therapeutic tools for hearing impairment is as yet unexplored, paving the way for future work in the field.
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Affiliation(s)
- Kathy Ushakov
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University Tel Aviv, Israel
| | - Anya Rudnicki
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University Tel Aviv, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University Tel Aviv, Israel
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Conte I, Banfi S, Bovolenta P. Non-coding RNAs in the development of sensory organs and related diseases. Cell Mol Life Sci 2013; 70:4141-55. [PMID: 23588489 PMCID: PMC11113508 DOI: 10.1007/s00018-013-1335-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 03/25/2013] [Accepted: 03/27/2013] [Indexed: 12/21/2022]
Abstract
Genomes are transcribed well beyond the conventionally annotated protein-encoding genes and produce many thousands of regulatory non-coding RNAs (ncRNAs). In the last few years, ncRNAs, especially microRNAs and long non-coding RNA, have received increasing attention because of their implication in the function of chromatin-modifying complexes and in the regulation of transcriptional and post-transcriptional events. The morphological events and the genetic networks responsible for the development of sensory organs have been well delineated and therefore sensory organs have provided a useful scenario to address the role of ncRNAs. In this review, we summarize the current information on the importance of microRNAs and long non-coding RNAs during the development of the eye, inner ear, and olfactory system in vertebrates. We will also discuss those cases in which alteration of ncRNA expression has been linked to pathological conditions affecting these organs.
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Affiliation(s)
- Ivan Conte
- Telethon Institute of Genetics and Medicine, Via Pietro Castellino, 111, 80131 Naples, Italy
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Via Pietro Castellino, 111, 80131 Naples, Italy
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy
| | - Paola Bovolenta
- Centro de Biología Molecular ‘Severo Ochoa’, CSIC–UAM, c/Nicolas Cabrera 1, Cantoblanco, 28049 Madrid, Spain
- CIBER de Enfermedades Raras, ISCIII, Madrid, Spain
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16
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Sun J, Lin Y, Wu J. Long non-coding RNA expression profiling of mouse testis during postnatal development. PLoS One 2013; 8:e75750. [PMID: 24130740 PMCID: PMC3794988 DOI: 10.1371/journal.pone.0075750] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 08/19/2013] [Indexed: 02/07/2023] Open
Abstract
Mammalian testis development and spermatogenesis play critical roles in male fertility and continuation of a species. Previous research into the molecular mechanisms of testis development and spermatogenesis has largely focused on the role of protein-coding genes and small non-coding RNAs, such as microRNAs and piRNAs. Recently, it has become apparent that large numbers of long (>200 nt) non-coding RNAs (lncRNAs) are transcribed from mammalian genomes and that lncRNAs perform important regulatory functions in various developmental processes. However, the expression of lncRNAs and their biological functions in post-natal testis development remain unknown. In this study, we employed microarray technology to examine lncRNA expression profiles of neonatal (6-day-old) and adult (8-week-old) mouse testes. We found that 8,265 lncRNAs were expressed above background levels during post-natal testis development, of which 3,025 were differentially expressed. Candidate lncRNAs were identified for further characterization by an integrated examination of genomic context, gene ontology (GO) enrichment of their associated protein-coding genes, promoter analysis for epigenetic modification, and evolutionary conservation of elements. Many lncRNAs overlapped or were adjacent to key transcription factors and other genes involved in spermatogenesis, such as Ovol1, Ovol2, Lhx1, Sox3, Sox9, Plzf, c-Kit, Wt1, Sycp2, Prm1 and Prm2. Most differentially expressed lncRNAs exhibited epigenetic modification marks similar to protein-coding genes and tend to be expressed in a tissue-specific manner. In addition, the majority of differentially expressed lncRNAs harbored evolutionary conserved elements. Taken together, our findings represent the first systematic investigation of lncRNA expression in the mammalian testis and provide a solid foundation for further research into the molecular mechanisms of lncRNAs function in mammalian testis development and spermatogenesis.
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Affiliation(s)
- Jin Sun
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| | - Yi Lin
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ji Wu
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Ningxia Medical University, Yinchuan, Ningxia, China
- * E-mail:
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Li CH, Chen Y. Targeting long non-coding RNAs in cancers: Progress and prospects. Int J Biochem Cell Biol 2013; 45:1895-910. [DOI: 10.1016/j.biocel.2013.05.030] [Citation(s) in RCA: 344] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 02/07/2023]
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Shi X, Sun M, Liu H, Yao Y, Song Y. Long non-coding RNAs: a new frontier in the study of human diseases. Cancer Lett 2013; 339:159-66. [PMID: 23791884 DOI: 10.1016/j.canlet.2013.06.013] [Citation(s) in RCA: 929] [Impact Index Per Article: 84.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/05/2013] [Accepted: 06/08/2013] [Indexed: 02/07/2023]
Abstract
With the development of whole genome and transcriptome sequencing technologies, long noncoding RNAs (lncRNAs) have received increased attention. Multiple studies indicate that lncRNAs act not only as the intermediary between DNA and protein but also as important protagonists of cellular functions. LncRNAs can regulate gene expression in many ways, including chromosome remodeling, transcription and post-transcriptional processing. Moreover, the dysregulation of lncRNAs has increasingly been linked to many human diseases, especially in cancers. Here, we reviewed the rapidly advancing field of lncRNAs and described the relationship between the dysregulation of lncRNAs and human diseases, highlighting the specific roles of lncRNAs in human diseases.
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Affiliation(s)
- Xuefei Shi
- Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
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Nadeau JH, Forejt J, Takada T, Shiroishi T. Chromosome substitution strains: gene discovery, functional analysis, and systems studies. Mamm Genome 2012; 23:693-705. [PMID: 22961226 DOI: 10.1007/s00335-012-9426-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Accepted: 08/02/2012] [Indexed: 12/31/2022]
Abstract
Laboratory mice are valuable in biomedical research in part because of the extraordinary diversity of genetic resources that are available for studies of complex genetic traits and as models for human biology and disease. Chromosome substitution strains (CSSs) are important in this resource portfolio because of their demonstrated use for gene discovery, genetic and epigenetic studies, functional characterizations, and systems analysis. CSSs are made by replacing a single chromosome in a host strain with the corresponding chromosome from a donor strain. A complete CSS panel involves a total of 22 engineered inbred strains, one for each of the 19 autosomes, one each for the X and Y chromosomes, and one for mitochondria. A genome survey simply involves comparing each phenotype for each of the CSSs with the phenotypes of the host strain. The CSS panels that are available for laboratory mice have been used to dissect a remarkable variety of phenotypes and to characterize an impressive array of disease models. These surveys have revealed considerable phenotypic diversity even among closely related progenitor strains, evidence for strong epistasis and for heritable epigenetic changes. Perhaps most importantly, and presumably because of their unique genetic constitution, CSSs, and congenic strains derived from them, the genetic variants underlying quantitative trait loci (QTLs) are readily identified and functionally characterized. Together these studies show that CSSs are important resource for laboratory mice.
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Affiliation(s)
- Joseph H Nadeau
- Pacific Northwest Research Institute, 720 Broadway, Seattle, WA 98122, USA.
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