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Kumar M, Has C, Lam-Kamath K, Ayciriex S, Dewett D, Bashir M, Poupault C, Schuhmann K, Thomas H, Knittelfelder O, Raghuraman BK, Ahrends R, Rister J, Shevchenko A. Eye proteome of Drosophila melanogaster. Proteomics 2024; 24:e2300330. [PMID: 37963819 PMCID: PMC11258641 DOI: 10.1002/pmic.202300330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/16/2023]
Abstract
Drosophila melanogaster is a popular model organism to elucidate the molecular mechanisms that underlie the structure and function of the eye as well as the causes of retinopathies, aging, light-induced damage, or dietary deficiencies. Large-scale screens have isolated genes whose mutation causes morphological and functional ocular defects, which led to the discovery of key components of the phototransduction cascade. However, the proteome of the Drosophila eye is poorly characterized. Here, we used GeLC-MS/MS to quantify 3516 proteins, including the absolute (molar) quantities of 43 proteins in the eye of adult male Drosophila reared on standard laboratory food. This work provides a generic and expandable resource for further genetic, pharmacological, and dietary studies.
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Affiliation(s)
- Mukesh Kumar
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Canan Has
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Khanh Lam-Kamath
- Department of Biology, University of Massachusetts Boston, Integrated Sciences Complex, 100 Morrissey Boulevard, Boston, MA 02125, USA
| | - Sophie Ayciriex
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Deepshe Dewett
- Department of Biology, University of Massachusetts Boston, Integrated Sciences Complex, 100 Morrissey Boulevard, Boston, MA 02125, USA
| | - Mhamed Bashir
- Department of Biology, University of Massachusetts Boston, Integrated Sciences Complex, 100 Morrissey Boulevard, Boston, MA 02125, USA
| | - Clara Poupault
- Department of Biology, University of Massachusetts Boston, Integrated Sciences Complex, 100 Morrissey Boulevard, Boston, MA 02125, USA
| | - Kai Schuhmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Henrik Thomas
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Oskar Knittelfelder
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Bharath Kumar Raghuraman
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Robert Ahrends
- Department of Analytical Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Jens Rister
- Department of Biology, University of Massachusetts Boston, Integrated Sciences Complex, 100 Morrissey Boulevard, Boston, MA 02125, USA
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
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2
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Son S, Jeong H, Lee G, Park JH, Yoo S. Biogenesis of circular RNAs in vitro and in vivo from the Drosophila Nk2.1 / scarecrow gene. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.26.582126. [PMID: 38463984 PMCID: PMC10925093 DOI: 10.1101/2024.02.26.582126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
scarecrow ( scro ) encodes a fly homolog of mammalian Nkx2.1 that is vital for early fly development as well as for optic lobe development. Interestingly, scro was reported to produce a circular RNA (circRNA). In this study, we identified 12 different scro circRNAs, which are either mono- or multi-exonic forms. The most abundant forms are circE2 carrying the second exon only and bi-exonic circE3-E4. Levels of circE2 show an age-dependent increase in adult heads, supporting a general trend of high accumulation of circRNAs in aged fly brains. Aligning sequences of introns flanking exons uncovered two pairs of intronic complementary sequences (ICSs); one pair residing in introns 1 and 2 and the other in introns 2 and 4. The first pair was demonstrated to be essential for the circE2 production in cell-based assays; furthermore, deletion of the region including potential ICS components in the intron-2 reduced in vivo production of circE2 and circE3-E4 by 80%, indicating them to be essential for the biogenesis of these isoforms. Besides the ICS, the intron regions immediately abutting exons seemed to be responsible for a basal level of circRNA formation. Moreover, the replacement of scro -ICS with those derived from laccase2 was comparably effective in scro -circRNA production, buttressing the importance of the hairpin-loop structure formed by ICS for the biogenesis of circRNA. Lastly, overexpressed scro affected outcomes of both linear and circular RNAs from the endogenous scro locus, suggesting that Scro plays a direct or indirect role in regulating expression levels of either or both forms.
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3
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Mir FA, Amanullah A, Jain BP, Hyderi Z, Gautam A. Neuroepigenetics of ageing and neurodegeneration-associated dementia: An updated review. Ageing Res Rev 2023; 91:102067. [PMID: 37689143 DOI: 10.1016/j.arr.2023.102067] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
Gene expression is tremendously altered in the brain during memory acquisition, recall, and forgetfulness. However, non-genetic factors, including environmental elements, epigenetic changes, and lifestyle, have grabbed significant attention in recent years regarding the etiology of neurodegenerative diseases (NDD) and age-associated dementia. Epigenetic modifications are essential in regulating gene expression in all living organisms in a DNA sequence-independent manner. The genes implicated in ageing and NDD-related memory disorders are epigenetically regulated by processes such as DNA methylation, histone acetylation as well as messenger RNA editing machinery. The physiological and optimal state of the epigenome, especially within the CNS of humans, plays an intricate role in helping us adjust to the changing environment, and alterations in it cause many brain disorders, but the mechanisms behind it still need to be well understood. When fully understood, these epigenetic landscapes could act as vital targets for pharmacogenetic rescue strategies for treating several diseases, including neurodegeneration- and age-induced dementia. Keeping this objective in mind, this updated review summarises the epigenetic changes associated with age and neurodegeneration-associated dementia.
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Affiliation(s)
- Fayaz Ahmad Mir
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Zeeshan Hyderi
- Department of Biotechnology, Alagappa University, Karaikudi, India
| | - Akash Gautam
- Centre for Neural and Cognitive Sciences, University of Hyderabad, Hyderabad, India.
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4
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Gao Z, Sun B, Fan Z, Su Y, Zheng C, Chen W, Yao Y, Ma C, Du Y. Vv-circSIZ1 mediated by pre-mRNA processing machinery contributes to salt tolerance. THE NEW PHYTOLOGIST 2023; 240:644-662. [PMID: 37530126 DOI: 10.1111/nph.19181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 07/11/2023] [Indexed: 08/03/2023]
Abstract
CircRNAs exist widely in plants, but the regulatory mechanisms for the biogenesis and function of plant circRNAs remain largely unknown. Using extensive mutagenesis of expression plasmids and genetic transformation methods, we analyzed the biogenesis and anti-salt functions of a new grape circRNA Vv-circSIZ1. We identified Vv-circSIZ1 that is mainly expressed in the cytoplasm of xylem. CircSIZ1 is species-specific, and genomic circSIZ1-forming region of seven tested species could be backspliced in Nicotiana benthamiana, but not in Arabidopsis. The retention length of Vv-circSIZ1 flanking introns was significantly positively correlated with its generation efficiency. The precise splicing of Vv-circSIZ1 does not depend on its mature exon sequence or internal intron sequences, but on the AG/GT splicing signal sites and branch site of the flanking introns. The spliceosome activity was inversely proportional to the expression level of Vv-circSIZ1. Furthermore, RNA-binding proteins can regulate the expression of Vv-circSIZ1. The overexpression of Vv-circSIZ1 improved salt tolerance of grape and N. benthamiana. Additionally, Vv-circSIZ1 could relieve the repressive effect of VvmiR3631 on its target VvVHAc1. Vv-circSIZ1 also promoted transcription of its parental gene. Overall, these results broaden our understanding of circRNAs in plants.
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Affiliation(s)
- Zhen Gao
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Baozhen Sun
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Zongbao Fan
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Yifan Su
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Chengchao Zheng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Weiping Chen
- Institute of Horticulture, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan, Ningxia, 750002, China
| | - Yuxin Yao
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Chao Ma
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yuanpeng Du
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China
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5
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Titus MB, Chang AW, Popitsch N, Ebmeier CC, Bono JM, Olesnicky EC. The identification of protein and RNA interactors of the splicing factor Caper in the adult Drosophila nervous system. Front Mol Neurosci 2023; 16:1114857. [PMID: 37435576 PMCID: PMC10332324 DOI: 10.3389/fnmol.2023.1114857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 05/19/2023] [Indexed: 07/13/2023] Open
Abstract
Post-transcriptional gene regulation is a fundamental mechanism that helps regulate the development and healthy aging of the nervous system. Mutations that disrupt the function of RNA-binding proteins (RBPs), which regulate post-transcriptional gene regulation, have increasingly been implicated in neurological disorders including amyotrophic lateral sclerosis, Fragile X Syndrome, and spinal muscular atrophy. Interestingly, although the majority of RBPs are expressed widely within diverse tissue types, the nervous system is often particularly sensitive to their dysfunction. It is therefore critical to elucidate how aberrant RNA regulation that results from the dysfunction of ubiquitously expressed RBPs leads to tissue specific pathologies that underlie neurological diseases. The highly conserved RBP and alternative splicing factor Caper is widely expressed throughout development and is required for the development of Drosophila sensory and motor neurons. Furthermore, caper dysfunction results in larval and adult locomotor deficits. Nonetheless, little is known about which proteins interact with Caper, and which RNAs are regulated by Caper. Here we identify proteins that interact with Caper in both neural and muscle tissue, along with neural specific Caper target RNAs. Furthermore, we show that a subset of these Caper-interacting proteins and RNAs genetically interact with caper to regulate Drosophila gravitaxis behavior.
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Affiliation(s)
- M. Brandon Titus
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Adeline W. Chang
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Niko Popitsch
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | | | - Jeremy M. Bono
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Eugenia C. Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
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6
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Escobedo SE, McGovern SE, Jauregui-Lozano JP, Stanhope SC, Anik P, Singhal K, DeBernardis R, Weake VM. Targeted RNAi screen identifies transcriptional mechanisms that prevent premature degeneration of adult photoreceptors. FRONTIERS IN EPIGENETICS AND EPIGENOMICS 2023; 1:1187980. [PMID: 37901602 PMCID: PMC10603763 DOI: 10.3389/freae.2023.1187980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Aging is associated with a decline in visual function and increased prevalence of ocular disease, correlating with changes in the transcriptome and epigenome of cells in the eye. Here, we sought to identify the transcriptional mechanisms that are necessary to maintain photoreceptor viability and function during aging. To do this, we performed a targeted photoreceptor-specific RNAi screen in Drosophila to identify transcriptional regulators whose knockdown results in premature, age-dependent retinal degeneration. From an initial set of 155 RNAi lines each targeting a unique gene and spanning a diverse set of transcription factors, chromatin remodelers, and histone modifiers, we identified 18 high-confidence target genes whose decreased expression in adult photoreceptors leads to premature and progressive retinal degeneration. These 18 target genes were enriched for factors involved in the regulation of transcription initiation, pausing, and elongation, suggesting that these processes are essential for maintaining the health of aging photoreceptors. To identify the genes regulated by these factors, we profiled the photoreceptor transcriptome in a subset of lines. Strikingly, two of the 18 target genes, Spt5 and domino, show similar changes in gene expression to those observed in photoreceptors with advanced age. Together, our data suggest that dysregulation of factors involved in transcription initiation and elongation plays a key role in shaping the transcriptome of aging photoreceptors. Further, our findings indicate that the age-dependent changes in gene expression not only correlate but might also contribute to an increased risk of retinal degeneration.
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Affiliation(s)
- Spencer E. Escobedo
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Sarah E. McGovern
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | | | - Sarah C. Stanhope
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Paul Anik
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Kratika Singhal
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Ryan DeBernardis
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, United States
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7
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Stanhope SC, Brandwine-Shemmer T, Blum HR, Doud EH, Jannasch A, Mosley AL, Minke B, Weake VM. Proteome-wide quantitative analysis of redox cysteine availability in the Drosophila melanogaster eye reveals oxidation of phototransduction machinery during blue light exposure and age. Redox Biol 2023; 63:102723. [PMID: 37146512 DOI: 10.1016/j.redox.2023.102723] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 05/07/2023] Open
Abstract
The retina is one of the highest oxygen-consuming tissues because visual transduction and light signaling processes require large amounts of ATP. Thus, because of the high energy demand, oxygen-rich environment, and tissue transparency, the eye is susceptible to excess production of reactive oxygen species (ROS) resulting in oxidative stress. Oxidative stress in the eye is associated with the development and progression of ocular diseases including cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy. ROS can modify and damage cellular proteins, but can also be involved in redox signaling. In particular, the thiol groups of cysteines can undergo reversible or irreversible oxidative post-translational modifications (PTMs). Identifying the redox-sensitive cysteines on a proteome-wide scale provides insight into those proteins that act as redox sensors or become irreversibly damaged upon exposure to oxidative stress. In this study, we profiled the redox proteome of the Drosophila eye under prolonged, high intensity blue light exposure and age using iodoacetamide isobaric label sixplex reagents (iodo-TMT) to identify changes in cysteine availability. Although redox metabolite analysis of the major antioxidant, glutathione, revealed similar ratios of its oxidized and reduced form in aged or light-stressed eyes, we observed different changes in the redox proteome under these conditions. Both conditions resulted in significant oxidation of proteins involved in phototransduction and photoreceptor maintenance but affected distinct targets and cysteine residues. Moreover, redox changes induced by blue light exposure were accompanied by a large reduction in light sensitivity that did not arise from a reduction in the photopigment level, suggesting that the redox-sensitive cysteines we identified in the phototransduction machinery might contribute to light adaptation. Our data provide a comprehensive description of the redox proteome of Drosophila eye tissue under light stress and aging and suggest how redox signaling might contribute to light adaptation in response to acute light stress.
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Affiliation(s)
- Sarah C Stanhope
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Tal Brandwine-Shemmer
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada (IMRIC), Edmond and Lily Safra Center for Brain Sciences (ELSC), Faculty of Medicine, The Hebrew University, Jerusalem, 91120, Israel
| | - Hannah R Blum
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Emma H Doud
- Center for Proteome Analysis, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Amber Jannasch
- Bindley Bioscience Center, Purdue University, West Lafayette, IN, 47907, USA
| | - Amber L Mosley
- Center for Proteome Analysis, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Baruch Minke
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada (IMRIC), Edmond and Lily Safra Center for Brain Sciences (ELSC), Faculty of Medicine, The Hebrew University, Jerusalem, 91120, Israel
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA.
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8
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Tassinari V, La Rosa P, Guida E, Colopi A, Caratelli S, De Paolis F, Gallo A, Cenciarelli C, Sconocchia G, Dolci S, Cesarini V. Contribution of A-to-I RNA editing, M6A RNA Methylation, and Alternative Splicing to physiological brain aging and neurodegenerative diseases. Mech Ageing Dev 2023; 212:111807. [PMID: 37023929 DOI: 10.1016/j.mad.2023.111807] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Abstract
Aging is a physiological and progressive phenomenon in all organisms' life cycle, characterized by the accumulation of degenerative processes triggered by several alterations within molecular pathways. These changes compromise cell fate, resulting in the loss of functions in tissues throughout the body, including the brain. Physiological brain aging has been linked to structural and functional alterations, as well as to an increased risk of neurodegenerative diseases. Post-transcriptional RNA modifications modulate mRNA coding properties, stability, translatability, expanding the coding capacity of the genome, and are involved in all cellular processes. Among mRNA post-transcriptional modifications, the A-to-I RNA editing, m6A RNA Methylation and Alternative Splicing play a critical role in all the phases of a neuronal cell life cycle and alterations in their mechanisms of action significantly contribute to aging and neurodegeneration. Here we review our current understanding of the contribution of A-to-I RNA editing, m6A RNA Methylation, and Alternative Splicing to physiological brain aging process and neurodegenerative diseases.
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Affiliation(s)
- Valentina Tassinari
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy; Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Eugenia Guida
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Ambra Colopi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Sara Caratelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Francesca De Paolis
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Angela Gallo
- RNA Editing Lab., Oncohaematology Department, Cellular and Gene Therapy Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Carlo Cenciarelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Giuseppe Sconocchia
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Susanna Dolci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Valeriana Cesarini
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy.
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9
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Rathore S, Meece M, Charlton-Perkins M, Cook TA, Buschbeck EK. Probing the conserved roles of cut in the development and function of optically different insect compound eyes. Front Cell Dev Biol 2023; 11:1104620. [PMID: 37065850 PMCID: PMC10102356 DOI: 10.3389/fcell.2023.1104620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Astonishing functional diversity exists among arthropod eyes, yet eye development relies on deeply conserved genes. This phenomenon is best understood for early events, whereas fewer investigations have focused on the influence of later transcriptional regulators on diverse eye organizations and the contribution of critical support cells, such as Semper cells (SCs). As SCs in Drosophila melanogaster secrete the lens and function as glia, they are critical components of ommatidia. Here, we perform RNAi-based knockdowns of the transcription factor cut (CUX in vertebrates), a marker of SCs, the function of which has remained untested in these cell types. To probe for the conserved roles of cut, we investigate two optically different compound eyes: the apposition optics of D. melanogaster and the superposition optics of the diving beetle Thermonectus marmoratus. In both cases, we find that multiple aspects of ocular formation are disrupted, including lens facet organization and optics as well as photoreceptor morphogenesis. Together, our findings support the possibility of a generalized role for SCs in arthropod ommatidial form and function and introduces Cut as a central player in mediating this role.
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Affiliation(s)
- Shubham Rathore
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Michael Meece
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Mark Charlton-Perkins
- Division of Developmental Biology and Department of Pediatric Ophthalmology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genetics, Department of Ophthalmological, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
| | - Elke K. Buschbeck
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
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10
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Jauregui-Lozano J, McGovern SE, Bakhle KM, Hagins AC, Weake VM. Establishing the contribution of active histone methylation marks to the aging transcriptional landscape of Drosophila photoreceptors. Sci Rep 2023; 13:5105. [PMID: 36991154 PMCID: PMC10060402 DOI: 10.1038/s41598-023-32273-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/24/2023] [Indexed: 03/31/2023] Open
Abstract
Studies in multiple organisms have shown that aging is accompanied by several molecular phenotypes that include dysregulation of chromatin. Since chromatin regulates DNA-based processes such as transcription, alterations in chromatin modifications could impact the transcriptome and function of aging cells. In flies, as in mammals, the aging eye undergoes changes in gene expression that correlate with declining visual function and increased risk of retinal degeneration. However, the causes of these transcriptome changes are poorly understood. Here, we profiled chromatin marks associated with active transcription in the aging Drosophila eye to understand how chromatin modulates transcriptional outputs. We found that both H3K4me3 and H3K36me3 globally decrease across all actively expressed genes with age. However, we found no correlation with changes in differential gene expression. Downregulation of the H3K36me3 methyltransferase Set2 in young photoreceptors revealed significant changes in splicing events that overlapped significantly with those observed in aging photoreceptors. These overlapping splicing events impacted multiple genes involved in phototransduction and neuronal function. Since proper splicing is essential for visual behavior, and because aging Drosophila undergo a decrease in visual function, our data suggest that H3K36me3 could play a role in maintaining visual function in the aging eye through regulating alternative splicing.
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Affiliation(s)
- Juan Jauregui-Lozano
- Department of Biochemistry, Purdue University, 175 S. University Street, West Lafayette, IN, 47907, USA
- University of California San Diego, San Diego, CA, 92093, USA
| | - Sarah E McGovern
- Department of Biochemistry, Purdue University, 175 S. University Street, West Lafayette, IN, 47907, USA
| | - Kimaya M Bakhle
- Department of Biochemistry, Purdue University, 175 S. University Street, West Lafayette, IN, 47907, USA
| | - Arrianna C Hagins
- Department of Biochemistry, Purdue University, 175 S. University Street, West Lafayette, IN, 47907, USA
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, 175 S. University Street, West Lafayette, IN, 47907, USA.
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA.
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11
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Kumar M, Has C, Lam-Kamath K, Ayciriex S, Dewett D, Bashir M, Poupault C, Schuhmann K, Knittelfelder O, Raghuraman BK, Ahrends R, Rister J, Shevchenko A. Eye proteome of Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.04.531088. [PMID: 36945598 PMCID: PMC10028839 DOI: 10.1101/2023.03.04.531088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
The Drosophila melanogaster eye is a popular model to elucidate the molecular mechanisms that underlie the structure and function of the eye as well as the causes of retinopathies. For instance, the Drosophila eye has been used to investigate the impacts of ageing and environmental stresses such as light-induced damage or dietary deficiencies. Moreover, large-scale screens have isolated genes whose mutation causes morphological and functional ocular defects, which includes key components of the phototransduction cascade. However, the proteome of the Drosophila eye is poorly characterized. Here, we used GeLC-MS/MS to quantify 3516 proteins he adult Drosophila melanogaster eye and provide a generic and expandable resource for further genetic, pharmacological, and dietary studies.
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12
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Noncoding RNA Regulation of Hormonal and Metabolic Systems in the Fruit Fly Drosophila. Metabolites 2023; 13:metabo13020152. [PMID: 36837772 PMCID: PMC9967906 DOI: 10.3390/metabo13020152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
The importance of RNAs is commonly recognised thanks to protein-coding RNAs, whereas non-coding RNAs (ncRNAs) were conventionally regarded as 'junk'. In the last decade, ncRNAs' significance and roles are becoming noticeable in various biological activities, including those in hormonal and metabolic regulation. Among the ncRNAs: microRNA (miRNA) is a small RNA transcript with ~20 nucleotides in length; long non-coding RNA (lncRNA) is an RNA transcript with >200 nucleotides; and circular RNA (circRNA) is derived from back-splicing of pre-mRNA. These ncRNAs can regulate gene expression levels at epigenetic, transcriptional, and post-transcriptional levels through various mechanisms in insects. A better understanding of these crucial regulators is essential to both basic and applied entomology. In this review, we intend to summarise and discuss the current understanding and knowledge of miRNA, lncRNA, and circRNA in the best-studied insect model, the fruit fly Drosophila.
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13
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Qiu J, Chen R, Zhao L, Lian C, Liu Z, Zhu X, Cui J, Wang S, Wang M, Huang Y, Wang S, Wang J. Circular RNA circGSE1 promotes angiogenesis in ageing mice by targeting the miR-323-5p/NRP1 axis. Aging (Albany NY) 2022; 14:3049-3069. [PMID: 35366240 PMCID: PMC9037273 DOI: 10.18632/aging.203988] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/15/2022] [Indexed: 11/29/2022]
Abstract
Age is an important factor in many cardiovascular diseases, in which endothelial cells (ECs) play an important role. Circular RNAs (circRNAs) have been reported in many cardiovascular diseases, but their role in ageing EC-related angiogenesis is unclear. We aimed to identify a functional circRNA that regulates angiogenesis during ageing and explore its specific mechanism. In this study, we searched for differentially expressed circRNAs in old endothelial cells (OECs) and young endothelial cells (YECs) by circRNA sequencing and found that circGSE1 was significantly downregulated in OECs. Our study showed that circGSE1 could promote the proliferation, migration and tube formation of OECs in vitro. In a mouse model of femoral artery ligation and ischemia, circGSE1 promoted blood flow recovery and angiogenesis in the ischemic limbs of ageing mice. Mechanistically, we found that overexpressing circGSE1 reduced miR-323-5p expression, increased neuropilin-1 (NRP1) expression, and promoted proliferation, migration, and tube formation in OECs, while knocking down circGSE1 increased miR-323-5p expression, reduced NRP1 expression, and inhibited proliferation, migration, and tube formation in YECs. During EC ageing, circGSE1 may act through the miR-323-5p/NRP1 axis and promote endothelial angiogenesis in mice. Finally, the circGSE1/miR-323-5p/NRP1 axis could serve as a potential and promising therapeutic target for angiogenesis during ageing.
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Affiliation(s)
- Jiacong Qiu
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Rencong Chen
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Lei Zhao
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Chong Lian
- Department of Endovascular Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450000, Henan, China
| | - Zhen Liu
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Xiaonan Zhu
- Department of Pharmacology Laboratory, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China
| | - Jin Cui
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Siwen Wang
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Mingshan Wang
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Yingxiong Huang
- Department of Emergency, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China
| | - Shenming Wang
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
| | - Jinsong Wang
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, Guangdong, China.,National-Local Joint Engineering Laboratory of Vascular Disease Treatment, Guangzhou 510080, Guangdong, China.,Guangdong Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases, Guangzhou 510080, Guangdong, China
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14
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Jauregui‐Lozano J, Escobedo S, Easton A, Lanman N, Weake VM, Hall H. Proper control of R-loop homeostasis is required for maintenance of gene expression and neuronal function during aging. Aging Cell 2022; 21:e13554. [PMID: 35048512 PMCID: PMC8844117 DOI: 10.1111/acel.13554] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 12/03/2021] [Accepted: 01/03/2022] [Indexed: 01/25/2023] Open
Abstract
Age‐related loss of cellular function and increased cell death are characteristic hallmarks of aging. While defects in gene expression and RNA metabolism have been linked with age‐associated human neuropathies, it is not clear how the changes that occur in aging neurons contribute to loss of gene expression homeostasis. R‐loops are RNA–DNA hybrids that typically form co‐transcriptionally via annealing of the nascent RNA to the template DNA strand, displacing the non‐template DNA strand. Dysregulation of R‐loop homeostasis has been associated with both transcriptional impairment and genome instability. Importantly, a growing body of evidence links R‐loop accumulation with cellular dysfunction, increased cell death, and chronic disease onset. Here, we characterized the R‐loop landscape in aging Drosophila melanogaster photoreceptor neurons and showed that bulk R‐loop levels increased with age. Further, genome‐wide mapping of R‐loops revealed that transcribed genes accumulated R‐loops over gene bodies during aging, which correlated with decreased expression of long and highly expressed genes. Importantly, while photoreceptor‐specific down‐regulation of Top3β, a DNA/RNA topoisomerase associated with R‐loop resolution, lead to decreased visual function, over‐expression of Top3β or nuclear‐localized RNase H1, which resolves R‐loops, enhanced positive light response during aging. Together, our studies highlight the functional link between dysregulation of R‐loop homeostasis, gene expression, and visual function during aging.
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Affiliation(s)
| | - Spencer Escobedo
- Department of Biochemistry Purdue University West Lafayette Indiana USA
| | - Alyssa Easton
- Department of Agricultural and Biological Engineering Purdue University West Lafayette Indiana USA
| | - Nadia A. Lanman
- Department of Comparative Pathobiology College of Veterinary Medicine Purdue University West Lafayette Indiana USA
- Purdue University Center for Cancer Research Purdue University West Lafayette Indiana USA
| | - Vikki M. Weake
- Department of Biochemistry Purdue University West Lafayette Indiana USA
- Purdue University Center for Cancer Research Purdue University West Lafayette Indiana USA
| | - Hana Hall
- Department of Biochemistry Purdue University West Lafayette Indiana USA
- Purdue Institute for Integrative Neuroscience Purdue University West Lafayette Indiana USA
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15
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Aging and Light Stress Result in Overlapping and Unique Gene Expression Changes in Photoreceptors. Genes (Basel) 2022; 13:genes13020264. [PMID: 35205309 PMCID: PMC8872477 DOI: 10.3390/genes13020264] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/20/2022] Open
Abstract
Advanced age is one of the leading risk factors for vision loss and eye disease. Photoreceptors are the primary sensory neurons of the eye. The extended photoreceptor cell lifespan, in addition to its high metabolic needs due to phototransduction, makes it critical for these neurons to continually respond to the stresses associated with aging by mounting an appropriate gene expression response. Here, we sought to untangle the more general neuronal age-dependent transcriptional signature of photoreceptors with that induced by light stress. To do this, we aged flies or exposed them to various durations of blue light, followed by photoreceptor nuclei-specific transcriptome profiling. Using this approach, we identified genes that are both common and uniquely regulated by aging and light induced stress. Whereas both age and blue light induce expression of DNA repair genes and a neuronal-specific signature of death, both conditions result in downregulation of phototransduction. Interestingly, blue light uniquely induced genes that directly counteract the overactivation of the phototransduction signaling cascade. Lastly, unique gene expression changes in aging photoreceptors included the downregulation of genes involved in membrane potential homeostasis and mitochondrial function, as well as the upregulation of immune response genes. We propose that light stress contributes to the aging transcriptome of photoreceptors, but that there are also other environmental or intrinsic factors involved in age-associated photoreceptor gene expression signatures.
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16
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Jauregui-Lozano J, Hall H, Stanhope SC, Bakhle K, Marlin MM, Weake VM. The Clock:Cycle complex is a major transcriptional regulator of Drosophila photoreceptors that protects the eye from retinal degeneration and oxidative stress. PLoS Genet 2022; 18:e1010021. [PMID: 35100266 PMCID: PMC8830735 DOI: 10.1371/journal.pgen.1010021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/10/2022] [Accepted: 01/08/2022] [Indexed: 12/28/2022] Open
Abstract
The aging eye experiences physiological changes that include decreased visual function and increased risk of retinal degeneration. Although there are transcriptomic signatures in the aging retina that correlate with these physiological changes, the gene regulatory mechanisms that contribute to cellular homeostasis during aging remain to be determined. Here, we integrated ATAC-seq and RNA-seq data to identify 57 transcription factors that showed differential activity in aging Drosophila photoreceptors. These 57 age-regulated transcription factors include two circadian regulators, Clock and Cycle, that showed sustained increased activity during aging. When we disrupted the Clock:Cycle complex by expressing a dominant negative version of Clock (ClkDN) in adult photoreceptors, we observed changes in expression of 15–20% of genes including key components of the phototransduction machinery and many eye-specific transcription factors. Using ATAC-seq, we showed that expression of ClkDN in photoreceptors leads to changes in activity of 37 transcription factors and causes a progressive decrease in global levels of chromatin accessibility in photoreceptors. Supporting a key role for Clock-dependent transcription in the eye, expression of ClkDN in photoreceptors also induced light-dependent retinal degeneration and increased oxidative stress, independent of light exposure. Together, our data suggests that the circadian regulators Clock and Cycle act as neuroprotective factors in the aging eye by directing gene regulatory networks that maintain expression of the phototransduction machinery and counteract oxidative stress. Age-associated changes to the retinal transcriptome often correlate with physiological changes, such as loss of visual function and increase in cell death. However, the mechanisms that contribute to these transcriptomic changes are poorly understood. Here, we used a genomics/bioinformatics approach to identify transcription factor binding sites with differential activity in aging Drosophila retina outer photoreceptors. Amongst these age-regulated transcription factors, we identify the circadian regulators Clock and Cycle. Using a genetics approach, we find that photoreceptor-specific disruption of the Clock:Cycle complex makes the Drosophila eye susceptible to light-dependent retinal degeneration, and light-independent increase of oxidative stress, showing that a functional circadian clock contributes to visual health and function in Drosophila. Because disruption of circadian rhythms has been associated with the onset of several age-related eye diseases, our data shows that the Drosophila retina serves as a useful model to study how disruption of the circadian clock contributes to neurodegeneration in the retina.
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Affiliation(s)
- Juan Jauregui-Lozano
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Hana Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, United States of America
| | - Sarah C. Stanhope
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Kimaya Bakhle
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Makayla M. Marlin
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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17
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Escobedo SE, Shah A, Easton AN, Hall H, Weake VM. Characterizing a gene expression toolkit for eye- and photoreceptor-specific expression in Drosophila. Fly (Austin) 2021; 15:73-88. [PMID: 33899690 PMCID: PMC8078738 DOI: 10.1080/19336934.2021.1915683] [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: 11/18/2020] [Revised: 03/16/2021] [Accepted: 04/08/2021] [Indexed: 10/21/2022] Open
Abstract
Binary expression systems are a powerful tool for tissue- and cell-specific research. Many of the currently available Drosophila eye-specific drivers have not been systematically characterized for their expression level and cell-type specificity in the adult eye or during development. Here, we used a luciferase reporter to measure expression levels of different drivers in the adult Drosophila eye, and characterized the cell type-specificity of each driver using a fluorescent reporter in live 10-day-old adult males. We also further characterized the expression pattern of these drivers in various developmental stages. We compared several Gal4 drivers from the Bloomington Drosophila Stock Center (BDSC) including GMR-Gal4, longGMR-Gal4 and Rh1-Gal4 with newly developed Gal4 and QF2 drivers that are specific to different cell types in the adult eye. In addition, we generated drug-inducible Rh1-GSGal4 lines and compared their induced expression with an available GMR-GSGal4 line. Although both lines had significant induction of gene expression measured by luciferase activity, Rh1-GSGal4 was expressed at levels below the detection of the fluorescent reporter by confocal microscopy, while GMR-GSGal4 showed substantial reporter expression in the absence of drug by microscopy. Overall, our study systematically characterizes and compares a large toolkit of eye- and photoreceptor-specific drivers, while also uncovering some of the limitations of currently available expression systems in the adult eye.
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Affiliation(s)
| | - Aashka Shah
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Alyssa N. Easton
- Department of Agriculture and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Hana Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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18
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Quantitative Proteomic and Metabolomic Profiling Reveals Altered Mitochondrial Metabolism and Folate Biosynthesis Pathways in the Aging Drosophila Eye. Mol Cell Proteomics 2021; 20:100127. [PMID: 34332122 PMCID: PMC8385154 DOI: 10.1016/j.mcpro.2021.100127] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/09/2021] [Accepted: 07/21/2021] [Indexed: 11/26/2022] Open
Abstract
Aging is associated with increased risk of ocular disease, suggesting that age-associated molecular changes in the eye increase its vulnerability to damage. Although there are common pathways involved in aging at an organismal level, different tissues and cell types exhibit specific changes in gene expression with advanced age. Drosophila melanogaster is an established model system for studying aging and neurodegenerative disease that also provides a valuable model for studying age-associated ocular disease. Flies, like humans, exhibit decreased visual function and increased risk of retinal degeneration with age. Here, we profiled the aging proteome and metabolome of the Drosophila eye and compared these data with age-associated transcriptomic changes from both eyes and photoreceptors to identify alterations in pathways that could lead to age-related phenotypes in the eye. Of note, the proteomic and metabolomic changes observed in the aging eye are distinct from those observed in the head or whole fly, suggesting that tissue-specific changes in protein abundance and metabolism occur in the aging fly. Our integration of the proteomic, metabolomic, and transcriptomic data reveals that changes in metabolism, potentially due to decreases in availability of B vitamins, together with chronic activation of the immune response, may underpin many of the events observed in the aging Drosophila eye. We propose that targeting these pathways in the genetically tractable Drosophila system may help to identify potential neuroprotective approaches for neurodegenerative and age-related ocular diseases. Data are available via ProteomeXchange with identifier PXD027090. Tissue-specific changes in protein abundance occur in the aging Drosophila eye. Increase in mitochondrial metabolism enzyme abundance in the aging eye. Decrease in corneal lens protein abundance and calcium buffering in the aging eye. Dysregulated metabolism impacts vitamin B and methionine metabolism in the aging eye.
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19
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Emerging functions of circular RNA in aging. Trends Genet 2021; 37:819-829. [PMID: 34016449 DOI: 10.1016/j.tig.2021.04.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/05/2021] [Accepted: 04/22/2021] [Indexed: 01/22/2023]
Abstract
Circular RNA (circRNA) is a closed, single-stranded transcript widely detected in eukaryotes. Recent studies indicate that the levels of circRNAs change with age in various tissues in multiple species, ranging from nematodes to mammals. Here we discuss the functional roles of circRNAs in animal aging and longevity. We review studies regarding the differential expression of circRNAs that contributes to cellular senescence and the pathogenesis of aging-associated diseases. We explore the features of aging-associated circRNAs by discussing their potential as biomarkers of aging, tissue specificity, physiological roles, action mechanisms, and evolutionarily conserved characteristics. Our review provides insights into current progress in circRNA research and their significant functions in the aging process.
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20
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Rong R, Wang M, You M, Li H, Xia X, Ji D. Pathogenesis and prospects for therapeutic clinical application of noncoding RNAs in glaucoma: Systematic perspectives. J Cell Physiol 2021; 236:7097-7116. [PMID: 33634475 PMCID: PMC8451868 DOI: 10.1002/jcp.30347] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/24/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022]
Abstract
Noncoding ribonucleic acids (ncRNAs) are an increasingly studied class of RNA molecules with extensive biological activities, including important roles in human development, health, and disease. Glaucoma is a neurodegenerative disease of the retina, and one of the leading causes of blindness worldwide. However, the specific roles of ncRNAs in the development and progression of glaucoma are unclear, and related reports are fragmented. An in‐depth understanding of ncRNAs participating in the pathogenesis and progression of glaucoma would be helpful for opening up new avenues to facilitate the early diagnosis and clinical treatment. Therefore, in this review, we aimed to discuss the current research progress, the potentialfuture clinical applications and the research limitations of three critical classes of ncRNAs in glaucoma, namely microRNAs, long noncoding RNAs, and circular RNAs.
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Affiliation(s)
- Rong Rong
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
| | - Mengxiao Wang
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
| | - Mengling You
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
| | - Haibo Li
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
| | - Xiaobo Xia
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
| | - Dan Ji
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Ophthalmology, Changsha, Hunan, China
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21
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021. [PMID: 33565261 DOI: 10.1002/wrna.1643.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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22
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1643. [PMID: 33565261 DOI: 10.1002/wrna.1643] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/19/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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23
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The conserved alternative splicing factor caper regulates neuromuscular phenotypes during development and aging. Dev Biol 2021; 473:15-32. [PMID: 33508255 DOI: 10.1016/j.ydbio.2021.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/17/2022]
Abstract
RNA-binding proteins play an important role in the regulation of post-transcriptional gene expression throughout the nervous system. This is underscored by the prevalence of mutations in genes encoding RNA splicing factors and other RNA-binding proteins in a number of neurodegenerative and neurodevelopmental disorders. The highly conserved alternative splicing factor Caper is widely expressed throughout the developing embryo and functions in the development of various sensory neural subtypes in the Drosophila peripheral nervous system. Here we find that caper dysfunction leads to aberrant neuromuscular junction morphogenesis, as well as aberrant locomotor behavior during larval and adult stages. Despite its widespread expression, our results indicate that caper function is required to a greater extent within the nervous system, as opposed to muscle, for neuromuscular junction development and for the regulation of adult locomotor behavior. Moreover, we find that Caper interacts with the RNA-binding protein Fmrp to regulate adult locomotor behavior. Finally, we show that caper dysfunction leads to various phenotypes that have both a sex and age bias, both of which are commonly seen in neurodegenerative disorders in humans.
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24
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Zuo S, Li X, Bao W, Li S. Pre-mRNA processing factor 3 enhances the progression of keratinocyte-derived cutaneous squamous cell carcinoma by regulating the JAK2/STAT3 pathway. Sci Rep 2020; 10:8863. [PMID: 32483193 PMCID: PMC7264194 DOI: 10.1038/s41598-020-65928-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/12/2020] [Indexed: 12/24/2022] Open
Abstract
The precise role of pre-mRNA processing factors (PRPs) in human tumorigenesis has not been yet explored. The object of the present study was to explore the effects of PRP3 in a common metastatic skin cancer, keratinocyte-derived cutaneous squamous cell carcinoma (cSCCs). RT-qPCR and western blotting were conducted to measure the expression levels of PRP3 in various cSCC cell lines and cSCC tissues. A benign epidermal keratinocyte cell line was transfected with a eukaryotic expression plasmid to overexpress PRP3. In addition, the endogenous expression level of PRP3 in cSCC cells was silenced using a short hairpin RNA method, and the role of PRP3 on cell proliferation and migration was examined by Cell Counting Kit-8, colony formation, wound healing assay and Transwell assays following knockdown in cSCC cells, and overexpression in keratinovcyte cells. Elevated levels of PRP3 mRNA and protein were noted in cSCC cell lines or cSCC tissues compared with actinic keratosis (AK) or benign epidermal keratinocyte cell line, respectively. Upregulation of PRP3 expression was found to be associated with poor clinical outcomes in patients with cSCCs. The upregulation of PRP3 promoted cell viability, metastasis and the activity of the JAK2/STAT3 pathway in epidermal keratinocyte cells. Interestingly, loss of PRP3 had no obvious impact on cell viability and migration in benign epidermal keratinocyte cells. Functionally, the inhibition of the JAK2/STAT3 pathway reversed the increased cell viability and migration of cSCC cells induced by PRP3. Taken together, the present observations indicated that PRP3 served as a tumor active factor in cSCCs by targeting the JAK2/STAT3 pathway. Moreover, it is implied that impeding the PRP3 activity may selectively constrain cancer cell growth and migration with limited effect on normal skin cells.
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Affiliation(s)
- Siyao Zuo
- Department of Dermatology and Venereology, The First Hospital of Jilin University, Changchun, China
| | - Xin Li
- Department of Infectious Disease, The First Hospital of Jilin University, Changchun, China
| | - Wanguo Bao
- Department of Infectious Disease, The First Hospital of Jilin University, Changchun, China.
| | - Shanshan Li
- Department of Dermatology and Venereology, The First Hospital of Jilin University, Changchun, China.
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Wang S, Wang M, Wang B, Chen J, Cheng X, Sun X. Pre-mRNA Processing Factor 8 Accelerates the Progression of Hepatocellular Carcinoma by Regulating the PI3K/Akt Pathway. Onco Targets Ther 2020; 13:4717-4730. [PMID: 32547101 PMCID: PMC7263830 DOI: 10.2147/ott.s241214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/02/2020] [Indexed: 12/22/2022] Open
Abstract
Background The specific function of pre-mRNA processing factors (Prps) in human malignancies has not been yet investigated. The aim of the present study was to determine the impacts of Prp8 in a common human malignancy, hepatocellular carcinoma (HCC). Materials and Methods RT-qPCR and Western blotting were performed to measure the expression levels of Prp8 in various HCC cell lines and HCC tissues. A hepatic astrocyte line was transfected with a eukaryotic expression plasmid to overexpress Prp8. In addition, the endogenous expression level of Prp8 in HCC cells was silenced using a short hairpin RNA method, and the role of Prp8 on cell proliferation and migration was examined by Cell Counting Kit-8, wound healing assay and Transwell assays following knockdown in HCC cells, and overexpression in astrocytes. Results Upregulation of Prp8 expression was found to be associated with poor clinical outcomes in patients with HCC. The upregulation of Prp8 promoted cell viability, metastasis and the activity of the PI3K/Akt pathway in hepatic astrocytes cells and HCC cells. Interestingly, loss of Prp8 had no obvious impact on cell viability and migration in hepatic astrocytes, but significantly inhibit the cell malignancy of HCC cells. Functionally, the inhibition of the PI3K/Akt pathway reversed the increased cell viability and migration of HCC cells induced by Prp8 via inhibiting EMT process. Conclusion Collectively, the present results suggested that Prp8 served as a tumor promoter in HCC by targeting and regulating the PI3K/Akt pathway.
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Affiliation(s)
- Shouhan Wang
- Department of Hepatopancreatobiliary Surgery, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
| | - Min Wang
- Department of Pathology, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
| | - Bin Wang
- Department of Hepatopancreatobiliary Surgery, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
| | - Jiaqi Chen
- Department of Hepatopancreatobiliary Surgery, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
| | - Xianbin Cheng
- Department of Hepatopancreatobiliary Surgery, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
| | - Xiaodan Sun
- Department of 2nd Gynecologic Oncology Surgery, Cancer Hospital of Jilin Province, Changchun, People's Republic of China
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Xiao MS, Ai Y, Wilusz JE. Biogenesis and Functions of Circular RNAs Come into Focus. Trends Cell Biol 2020; 30:226-240. [PMID: 31973951 DOI: 10.1016/j.tcb.2019.12.004] [Citation(s) in RCA: 205] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/04/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023]
Abstract
Many eukaryotic protein-coding genes are able to generate exonic circular RNAs. Most of these covalently linked transcripts are expressed at low levels, but some accumulate to higher levels than their associated linear mRNAs. We highlight several methodologies that have been developed in recent years to identify and characterize these transcripts, and which have revealed an increasingly detailed view of how circular RNAs can be generated and function. It is now clear that modulation of circular RNA levels can result in a variety of molecular and physiological phenotypes, including effects on the nervous system, innate immunity, microRNAs, and many disease-relevant pathways.
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Affiliation(s)
- Mei-Sheng Xiao
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Yuxi Ai
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jeremy E Wilusz
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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Bhadra M, Howell P, Dutta S, Heintz C, Mair WB. Alternative splicing in aging and longevity. Hum Genet 2019; 139:357-369. [PMID: 31834493 DOI: 10.1007/s00439-019-02094-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 11/24/2019] [Indexed: 12/13/2022]
Abstract
Alternative pre-mRNA splicing increases the complexity of the proteome that can be generated from the available genomic coding sequences. Dysregulation of the splicing process has been implicated in a vast repertoire of diseases. However, splicing has recently been linked to both the aging process itself and pro-longevity interventions. This review focuses on recent research towards defining RNA splicing as a new hallmark of aging. We highlight dysfunctional alternative splicing events that contribute to the aging phenotype across multiple species, along with recent efforts toward deciphering mechanistic roles for RNA splicing in the regulation of aging and longevity. Further, we discuss recent research demonstrating a direct requirement for specific splicing factors in pro-longevity interventions, and specifically how nutrient signaling pathways interface to splicing factor regulation and downstream splicing targets. Finally, we review the emerging potential of using splicing profiles as a predictor of biological age and life expectancy. Understanding the role of RNA splicing components and downstream targets altered in aging may provide opportunities to develop therapeutics and ultimately extend healthy lifespan in humans.
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Affiliation(s)
- Malini Bhadra
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Porsha Howell
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Sneha Dutta
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Caroline Heintz
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - William B Mair
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
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Wang M, Hou J, Müller-McNicoll M, Chen W, Schuman EM. Long and Repeat-Rich Intronic Sequences Favor Circular RNA Formation under Conditions of Reduced Spliceosome Activity. iScience 2019; 20:237-247. [PMID: 31590076 PMCID: PMC6817660 DOI: 10.1016/j.isci.2019.08.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/19/2019] [Accepted: 08/30/2019] [Indexed: 02/02/2023] Open
Abstract
Circular RNAs (circRNAs), an important class of regulatory RNAs, have been shown to be the most prevalent in the brain compared with other tissues. However the processes governing their biogenesis in neurons are still elusive. Moreover, little is known about whether and how different biogenesis factors work in synchrony to generate neuronal circRNAs. To address this question, we pharmacologically inhibited the spliceosome and profiled rat neuronal circRNAs using RNA sequencing. We identified over 100 circRNAs that were up-regulated and a few circRNAs that were down-regulated upon spliceosome inhibition. Bioinformatic analysis revealed that up-regulated circRNAs possess significantly longer flanking introns compared with the un-changed circRNA population. Moreover, the flanking introns of up-regulated circRNAs harbor a higher number of distinct repeat sequences and more reverse complementary motifs compared with the unchanged circRNAs. Taken together, our data demonstrate that the biogenesis of circRNAs containing distinct intronic features becomes favored under conditions of limited spliceosome activity. RNA-seq reveals changes of the neuronal circRNA landscape after spliceosome inhibition Hundreds of circRNAs are up-regulated under conditions of reduced spliceosome activity Long and repeat-rich flanking introns facilitate up-regulation of cognate circRNAs
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Affiliation(s)
- Mantian Wang
- Max Planck Institute for Brain Research, Max-von-Laue-Str.4, 60438 Frankfurt am Main, Germany
| | - Jingyi Hou
- Max-Delbrueck-Center for Molecular Medicine, 13125 Berlin, Germany
| | | | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Max-von-Laue-Str.4, 60438 Frankfurt am Main, Germany.
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George AK, Master K, Majumder A, Homme RP, Laha A, Sandhu HS, Tyagi SC, Singh M. Circular RNAs constitute an inherent gene regulatory axis in the mammalian eye and brain. Can J Physiol Pharmacol 2019; 97:463-472. [DOI: 10.1139/cjpp-2018-0505] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Circular RNAs (circRNAs) are being hailed as a newly rediscovered class of covalently closed transcripts that are produced via alternative, noncanonical pre-mRNA back-splicing events. These single-stranded RNA molecules have been identified in organisms ranging from the worm (Cortés-López et al. 2018. BMC Genomics, 19: 8; Ivanov et al. 2015. Cell Rep. 10: 170–177) to higher eukaryotes (Yang et al. 2017. Cell Res. 27: 626–641) to plants (Li et al. 2017. Biochem. Biophys. Res. Commun. 488: 382–386). At present, research on circRNAs is an active area because of their diverse roles in development, health, and diseases. Partly because their circularity makes them resistant to degradation, they hold great promise as unique biomarkers for ocular and central nervous system (CNS) disorders. We believe that further work on their applications could help in developing them as “first-in-class” diagnostics, therapeutics, and prognostic targets for numerous eye conditions. Interestingly, many circRNAs play key roles in transcriptional regulation by acting as miRNAs sponges, meaning that they serve as master regulators of RNA and protein expression. Since the retina is an extension of the brain and is part of the CNS, we highlight the current state of circRNA biogenesis, properties, and function and we review the crucial roles that they play in the eye and the brain. We also discuss their regulatory roles as miRNA sponges, regulation of their parental genes or linear mRNAs, translation into micropeptides or proteins, and responses to cellular stress. We posit that future advances will provide newer insights into the fields of RNA metabolism in general and diseases of the aging eye and brain in particular. Furthermore, in keeping pace with the rapidly evolving discipline of RNA“omics”-centered metabolism and to achieve uniformity among researchers, we recently introduced the term “cromics” (circular ribonucleic acids based omics) (Singh et al. 2018. Exp. Eye Res. 174: 80–92).
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Affiliation(s)
- Akash K. George
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Kruyanshi Master
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India
| | - Avisek Majumder
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Rubens Petit Homme
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Anwesha Laha
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Harpal S. Sandhu
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Kentucky Lions Eye Center, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Suresh C. Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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Stegeman R, Hall H, Escobedo SE, Chang HC, Weake VM. Proper splicing contributes to visual function in the aging Drosophila eye. Aging Cell 2018; 17:e12817. [PMID: 30003673 PMCID: PMC6156539 DOI: 10.1111/acel.12817] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/06/2018] [Accepted: 06/18/2018] [Indexed: 12/19/2022] Open
Abstract
Changes in splicing patterns are a characteristic of the aging transcriptome; however, it is unclear whether these age-related changes in splicing facilitate the progressive functional decline that defines aging. In Drosophila, visual behavior declines with age and correlates with altered gene expression in photoreceptors, including downregulation of genes encoding splicing factors. Here, we characterized the significance of these age-regulated splicing-associated genes in both splicing and visual function. To do this, we identified differential splicing events in either the entire eye or photoreceptors of young and old flies. Intriguingly, aging photoreceptors show differential splicing of a large number of visual function genes. In addition, as shown previously for aging photoreceptors, aging eyes showed increased accumulation of circular RNAs, which result from noncanonical splicing events. To test whether proper splicing was necessary for visual behavior, we knocked down age-regulated splicing factors in photoreceptors in young flies and examined phototaxis. Notably, many of the age-regulated splicing factors tested were necessary for proper visual behavior. In addition, knockdown of individual splicing factors resulted in changes in both alternative splicing at age-spliced genes and increased accumulation of circular RNAs. Together, these data suggest that cumulative decreases in splicing factor expression could contribute to the differential splicing, circular RNA accumulation, and defective visual behavior observed in aging photoreceptors.
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Affiliation(s)
- Rachel Stegeman
- Department of BiochemistryPurdue UniversityWest LafayetteIndiana
- Present address:
University of Minnesota Medical SchoolMinneapolisMinnesota
| | - Hana Hall
- Department of BiochemistryPurdue UniversityWest LafayetteIndiana
| | | | - Henry C. Chang
- Department of Biological SciencesPurdue UniversityWest LafayetteIndiana
| | - Vikki M. Weake
- Department of BiochemistryPurdue UniversityWest LafayetteIndiana
- Purdue University Center for Cancer ResearchPurdue UniversityWest LafayetteIndiana
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