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Zacchini F, Barozzi C, Venturi G, Montanaro L. How snoRNAs can contribute to cancer at multiple levels. NAR Cancer 2024; 6:zcae005. [PMID: 38406265 PMCID: PMC10894041 DOI: 10.1093/narcan/zcae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/05/2024] [Accepted: 02/12/2024] [Indexed: 02/27/2024] Open
Abstract
snoRNAs are a class of non-coding RNAs known to guide site specifically RNA modifications such as 2'-O-methylation and pseudouridylation. Recent results regarding snoRNA alterations in cancer has been made available and suggest their potential evaluation as diagnostic and prognostic biomarkers. A large part of these data, however, was not consistently confirmed and failed to provide mechanistic insights on the contribution of altered snoRNA expression to the neoplastic process. Here, we aim to critically review the available literature on snoRNA in cancer focusing on the studies elucidating the functional consequences of their deregulation. Beyond the canonical guide function in RNA processing and modification we also considered additional roles in which snoRNA, in various forms and through different modalities, are involved and that have been recently reported.
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Affiliation(s)
- Federico Zacchini
- Departmental Program in Laboratory Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, I-40138 Bologna, Italy
| | - Chiara Barozzi
- Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum - University of Bologna, Bologna I-40138, Italy
| | - Giulia Venturi
- Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum - University of Bologna, Bologna I-40138, Italy
- Centre for Applied Biomedical Research – CRBA, University of Bologna, Sant’Orsola Hospital, Bologna I-40138, Italy
| | - Lorenzo Montanaro
- Departmental Program in Laboratory Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, I-40138 Bologna, Italy
- Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum - University of Bologna, Bologna I-40138, Italy
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Zhang R, Lang Y, Shi X, Zhang Y, Liu X, Pan F, Qiao D, Teng X, Shao L. Three exonic variants in the COL4A5 gene alter RNA splicing in a minigene assay. Mol Genet Genomic Med 2024; 12:e2395. [PMID: 38400605 PMCID: PMC10891438 DOI: 10.1002/mgg3.2395] [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: 09/05/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND X-linked Alport syndrome (XLAS) is an inherited renal disease caused by rare variants of COL4A5 on chromosome Xq22. Many studies have indicated that single nucleotide variants (SNVs) in exons can disrupt normal splicing process of the pre-mRNA by altering various splicing regulatory signals. The male patients with XLAS have a strong genotype-phenotype correlation. Confirming the effect of variants on splicing can help to predict kidney prognosis. This study aimed to investigate whether single nucleotide substitutions, located within three bases at the 5' end of the exons or internal position of the exons in COL4A5 gene, cause aberrant splicing process. METHODS We analyzed 401 SNVs previously presumed missense and nonsense variants in COL4A5 gene by bioinformatics programs and identified candidate variants that may affect the splicing of pre-mRNA via minigene assays. RESULTS Our study indicated three of eight candidate variants induced complete or partial exon skipping. Variants c.2678G>C and c.2918G>A probably disturb classic splice sites leading to corresponding exon skipping. Variant c.3700C>T may disrupt splicing enhancer motifs accompanying with generation of splicing silencer sequences resulting in the skipping of exon 41. CONCLUSION Our study revealed that two missense variants positioned the first nucleotides of the 5' end of COL4A5 exons and one internal exonic nonsense variant caused aberrant splicing. Importantly, this study emphasized the necessity of assessing the effects of SNVs at the mRNA level.
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Affiliation(s)
- Ran Zhang
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Yanhua Lang
- Department of Materialsthe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xiaomeng Shi
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Yiyin Zhang
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xuyan Liu
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Fengjiao Pan
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Dan Qiao
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xin Teng
- Department of Ultrasoundthe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Leping Shao
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
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3
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Michael FM, Patel SP, Bachstetter AD, Rabchevsky AG. Proinflammatory and Immunomodulatory Gene and Protein Expression Patterns in Spinal Cord and Spleen Following Acute and Chronic High Thoracic Injury. J Inflamm Res 2023; 16:3341-3349. [PMID: 37576153 PMCID: PMC10423003 DOI: 10.2147/jir.s417435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/04/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction In addition to paralysis and loss of sensation, high-level spinal cord injury (SCI) causes sympathetic dysfunction that can lead to autonomic dysreflexia (AD) and chronic immune suppression involving splenic leukopenia. Evidence has shown that treatment with either gabapentin or blockade of TNFα mitigates maladaptive plasticity and the underlying hemodynamic dysfunction, spleen atrophy, and immune dysfunction associated with AD. Because significant improvements long term was noted following treatments only during acute stages of recovery, we sought to systematically examine changes in proinflammatory and immunomodulatory cytokines to ascertain the reason. Methods Adult female Wistar rats underwent complete T4 spinal transection before euthanasia at systematic intervals from 3 days to 8 weeks after injury. Using qRT-PCR and meso scale discovery (MSD) assays, the gene and protein expression of TNFα and IFNγ in the spleen, upper thoracic (T4-9) and lumbosacral (L5-S6) spinal cords were analyzed. Results We found that spleen atrophy occurs in a biphasic manner compared to naïve controls, with significant decreases in the spleen mass noted at 3 days and 8 weeks after injury. Splenic TNFα mRNA and protein levels did not change significantly over time, while IFNγ gene expression dipped acutely with trends for increased protein levels at more chronic time points. TNFα protein increased significantly only in thoracic spinal cord segments from 3 to 14 days post-injury. IFNγ mRNA and protein levels remained unelevated in injured spinal cords over time, with trends for increased protein levels at 2 and 8 weeks in the lumbosacral segments. Discussion Novel temporal-spatial cytokine expression profiles reveal that TNFα protein levels are increased solely in upper thoracic segments after high thoracic SCI, while IFNγ remains unaltered. Splenic leukopenia and latent systemic immunosuppression are not associated with altered TNFα or IFNγ expression in the spleen or spinal cord.
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Affiliation(s)
- Felicia M Michael
- Department of Physiology, University of Kentucky, Lexington, KY, 40536-0509, USA
- Spinal Cord & Brain Injury Research Center (SCoBIRC); University of Kentucky, Lexington, KY, 40536-0509, USA
| | - Samir P Patel
- Department of Physiology, University of Kentucky, Lexington, KY, 40536-0509, USA
- Spinal Cord & Brain Injury Research Center (SCoBIRC); University of Kentucky, Lexington, KY, 40536-0509, USA
| | - Adam D Bachstetter
- Spinal Cord & Brain Injury Research Center (SCoBIRC); University of Kentucky, Lexington, KY, 40536-0509, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536-0509, USA
| | - Alexander G Rabchevsky
- Department of Physiology, University of Kentucky, Lexington, KY, 40536-0509, USA
- Spinal Cord & Brain Injury Research Center (SCoBIRC); University of Kentucky, Lexington, KY, 40536-0509, USA
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4
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Broni E, Striegel A, Ashley C, Sakyi PO, Peracha S, Velazquez M, Bebla K, Sodhi M, Kwofie SK, Ademokunwa A, Khan S, Miller WA. Molecular Docking and Dynamics Simulation Studies Predict Potential Anti-ADAR2 Inhibitors: Implications for the Treatment of Cancer, Neurological, Immunological and Infectious Diseases. Int J Mol Sci 2023; 24:ijms24076795. [PMID: 37047766 PMCID: PMC10095294 DOI: 10.3390/ijms24076795] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/01/2023] [Accepted: 04/04/2023] [Indexed: 04/08/2023] Open
Abstract
Altered RNA editing has been linked to several neurodevelopmental disorders, including autism spectrum disorder (ASD) and intellectual disability, in addition to depression, schizophrenia, some cancers, viral infections and autoimmune disorders. The human ADAR2 is a potential therapeutic target for managing these various disorders due to its crucial role in adenosine to inosine editing. This study applied consensus scoring to rank potential ADAR2 inhibitors after performing molecular docking with AutoDock Vina and Glide (Maestro), using a library of 35,161 compounds obtained from traditional Chinese medicine. A total of 47 compounds were predicted to be good binders of the human ADAR2 and had insignificant toxicity concerns. Molecular dynamics (MD) simulations, including the molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) procedure, also emphasized the binding of the shortlisted compounds. The potential compounds had plausible binding free energies ranging from −81.304 to −1068.26 kJ/mol from the MM/PBSA calculations. ZINC000085511995, a naphthoquinone had more negative binding free energy (−1068.26 kJ/mol) than inositol hexakisphosphate (IHP) [−873.873 kJ/mol], an agonist and a strong binder of ADAR2. The potential displacement of IHP by ZINC000085511995 in the IHP binding site of ADAR2 could be explored for possible deactivation of ADAR2. Bayesian-based biological activity prediction corroborates the neuropharmacological, antineoplastic and antiviral activity of the potential lead compounds. All the potential lead compounds, except ZINC000014612330 and ZINC000013462928, were predicted to be inhibitors of various deaminases. The potential lead compounds also had probability of activity (Pa) > 0.442 and probability of inactivity (Pi) < 0.116 values for treating acute neurologic disorders, except for ZINC000085996580 and ZINC000013462928. Pursuing these compounds for their anti-ADAR2 activities holds a promising future, especially against neurological disorders, some cancers and viral infections caused by RNA viruses. Molecular interaction, hydrogen bond and per-residue decomposition analyses predicted Arg400, Arg401, Lys519, Trp687, Glu689, and Lys690 as hot-spot residues in the ADAR2 IHP binding site. Most of the top compounds were observed to have naphthoquinone, indole, furanocoumarin or benzofuran moieties. Serotonin and tryptophan, which are beneficial in digestive regulation, improving sleep cycle and mood, are indole derivatives. These chemical series may have the potential to treat neurological disorders, prion diseases, some cancers, specific viral infections, metabolic disorders and eating disorders through the disruption of ADAR2 pathways. A total of nine potential lead compounds were shortlisted as plausible modulators of ADAR2.
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Affiliation(s)
- Emmanuel Broni
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Andrew Striegel
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Chemical and Biochemistry, College of Science, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Carolyn Ashley
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Patrick O. Sakyi
- Department of Chemistry, School of Physical and Mathematical Sciences, College of Basic and Applied Sciences, University of Ghana, Legon, Accra P.O. Box LG 56, Ghana
- Department of Chemical Sciences, School of Sciences, University of Energy and Natural Resources, Sunyani P.O. Box 214, Ghana
| | - Saqib Peracha
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Miriam Velazquez
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Molecular Pharmacology & Neuroscience, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Kristeen Bebla
- Department of Molecular Pharmacology & Neuroscience, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Monsheel Sodhi
- Department of Molecular Pharmacology & Neuroscience, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
| | - Samuel K. Kwofie
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic & Applied Sciences, University of Ghana, Legon, Accra P.O. Box LG 77, Ghana
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra P.O. Box LG 54, Ghana
| | - Adesanya Ademokunwa
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Cognitive and Behavioral Neuroscience, Loyola University Chicago, Chicago, IL 60660, USA
| | - Sufia Khan
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Whelton A. Miller
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Molecular Pharmacology & Neuroscience, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
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Microdeletion of 4p16.2 in Children: A Case Report and Literature Review. Case Rep Genet 2022; 2022:6253690. [PMID: 35437470 PMCID: PMC9013304 DOI: 10.1155/2022/6253690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 03/16/2022] [Accepted: 03/29/2022] [Indexed: 11/17/2022] Open
Abstract
Copy number variations (CNV) are thought to play an important role in causing human diseases, including congenital anomalies, psychiatric disorders, and intellectual disabilities. We report here a one-year-old boy presented to our clinic as developmental delay. He presented a birth weight of 4.5 kg, motor delay, mental retardation, mild hypertonia, and some dysmorphic features (mild frontal bossing, hypertelorism, epicanthus, concave nasal ridge, slightly sparse hair, short hands, and mild nail dysplasia). The brain MRI indicated brain abnormalities; the Gross Motor Function Measure-66 score was 23.37; the Gesell test result showed the development quotient was 50, suggesting mental retardation. Chromosomal microarray analysis showed an approximately 97 kb microdeletion at 4p16.2 (4p16.2 CNV), including part of EVC and EVC2 genes, which were associated with Ellis-van Creveld syndrome (EvC) and Weyers acrofacial dysostosis (WAD). This report suggests 4p16.2 microdeletion may be associated with multiple developmental abnormalities, including motor delay and mental retardation.
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Sergeeva OV, Shcherbinina EY, Shomron N, Zatsepin TS. Modulation of RNA Splicing by Oligonucleotides: Mechanisms of Action and Therapeutic Implications. Nucleic Acid Ther 2022; 32:123-138. [PMID: 35166605 DOI: 10.1089/nat.2021.0067] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of RNA splicing causes many diseases and disorders. Several therapeutic approaches have been developed to correct aberrant alternative splicing events for the treatment of cancers and hereditary diseases, including gene therapy and redirecting splicing, using small molecules or splice switching oligonucleotides (SSO). Significant advances in the chemistry and pharmacology of nucleic acid have led to the development of clinically approved SSO drugs for the treatment of spinal muscular dystrophy and Duchenne muscular dystrophy (DMD). In this review, we discuss the mechanisms of SSO action with emphasis on "less common" approaches to modulate alternative splicing, including bipartite and bifunctional SSO, oligonucleotide decoys for splice factors and SSO-mediated mRNA degradation via AS-NMD and NGD pathways. We briefly discuss the current progress and future perspectives of SSO therapy for rare and ultrarare diseases.
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Affiliation(s)
- Olga V Sergeeva
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
| | | | - Noam Shomron
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Timofei S Zatsepin
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia.,Department of Chemistry, Moscow State University, Moscow, Russia
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7
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Nagata T, Dwyer CA, Yoshida-Tanaka K, Ihara K, Ohyagi M, Kaburagi H, Miyata H, Ebihara S, Yoshioka K, Ishii T, Miyata K, Miyata K, Powers B, Igari T, Yamamoto S, Arimura N, Hirabayashi H, Uchihara T, Hara RI, Wada T, Bennett CF, Seth PP, Rigo F, Yokota T. Cholesterol-functionalized DNA/RNA heteroduplexes cross the blood-brain barrier and knock down genes in the rodent CNS. Nat Biotechnol 2021; 39:1529-1536. [PMID: 34385691 DOI: 10.1038/s41587-021-00972-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 06/02/2021] [Indexed: 02/07/2023]
Abstract
Achieving regulation of endogenous gene expression in the central nervous system (CNS) with antisense oligonucleotides (ASOs) administered systemically would facilitate the development of ASO-based therapies for neurological diseases. We demonstrate that DNA/RNA heteroduplex oligonucleotides (HDOs) conjugated to cholesterol or α-tocopherol at the 5' end of the RNA strand reach the CNS after subcutaneous or intravenous administration in mice and rats. The HDOs distribute throughout the brain, spinal cord and peripheral tissues and suppress the expression of four target genes by up to 90% in the CNS, whereas single-stranded ASOs conjugated to cholesterol have limited activity. Gene knockdown was observed in major CNS cell types and was greatest in neurons and microglial cells. Side effects, such as thrombocytopenia and focal brain necrosis, were limited by using subcutaneous delivery or by dividing intravenous injections. By crossing the blood-brain barrier more effectively, cholesterol-conjugated HDOs may overcome the limited efficacy of ASOs targeting the CNS without requiring intrathecal administration.
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Affiliation(s)
- Tetsuya Nagata
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | | | - Kie Yoshida-Tanaka
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kensuke Ihara
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masaki Ohyagi
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hidetoshi Kaburagi
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Haruka Miyata
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Satoe Ebihara
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kotaro Yoshioka
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takashi Ishii
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kanjiro Miyata
- Department of Materials Engineering, Graduate School of Engineering, University of Tokyo, Tokyo, Japan
| | - Kenichi Miyata
- Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | | | - Tomoko Igari
- Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | | | - Naoto Arimura
- Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | | | - Toshiki Uchihara
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Rintaro Iwata Hara
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan.,Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
| | - Takeshi Wada
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
| | | | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | - Takanori Yokota
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. .,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan.
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Emerging Functions for snoRNAs and snoRNA-Derived Fragments. Int J Mol Sci 2021; 22:ijms221910193. [PMID: 34638533 PMCID: PMC8508363 DOI: 10.3390/ijms221910193] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 12/11/2022] Open
Abstract
The widespread implementation of mass sequencing has revealed a diverse landscape of small RNAs derived from larger precursors. Whilst many of these are likely to be byproducts of degradation, there are nevertheless metabolically stable fragments derived from tRNAs, rRNAs, snoRNAs, and other non-coding RNA, with a number of examples of the production of such fragments being conserved across species. Coupled with specific interactions to RNA-binding proteins and a growing number of experimentally reported examples suggesting function, a case is emerging whereby the biological significance of small non-coding RNAs extends far beyond miRNAs and piRNAs. Related to this, a similarly complex picture is emerging of non-canonical roles for the non-coding precursors, such as for snoRNAs that are also implicated in such areas as the silencing of gene expression and the regulation of alternative splicing. This is in addition to a body of literature describing snoRNAs as an additional source of miRNA-like regulators. This review seeks to highlight emerging roles for such non-coding RNA, focusing specifically on “new” roles for snoRNAs and the small fragments derived from them.
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9
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Yao T, He J, Cui Z, Wang R, Bao K, Huang Y, Wang R, Liu T. Central 5-HTR2C in the Control of Metabolic Homeostasis. Front Endocrinol (Lausanne) 2021; 12:694204. [PMID: 34367066 PMCID: PMC8334728 DOI: 10.3389/fendo.2021.694204] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/06/2021] [Indexed: 11/29/2022] Open
Abstract
The 5-hydroxytryptamine 2C receptor (5-HTR2C) is a class G protein-coupled receptor (GPCR) enriched in the hypothalamus and the brain stem, where it has been shown to regulate energy homeostasis, including feeding and glucose metabolism. Accordingly, 5-HTR2C has been the target of several anti-obesity drugs, though the associated side effects greatly curbed their clinical applications. Dissecting the specific neural circuits of 5-HTR2C-expressing neurons and the detailed molecular pathways of 5-HTR2C signaling in metabolic regulation will help to develop better therapeutic strategies towards metabolic disorders. In this review, we introduced the regulatory role of 5-HTR2C in feeding behavior and glucose metabolism, with particular focus on the molecular pathways, neural network, and its interaction with other metabolic hormones, such as leptin, ghrelin, insulin, and estrogens. Moreover, the latest progress in the clinical research on 5-HTR2C agonists was also discussed.
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Affiliation(s)
- Ting Yao
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi’an Jiaotong University School of Medicine, Xi’an, China
- *Correspondence: Ting Yao, ; Ru Wang, ; Tiemin Liu,
| | - Jiehui He
- School of Life Sciences, Fudan University, Shanghai, China
| | - Zhicheng Cui
- School of Life Sciences, Fudan University, Shanghai, China
| | - Ruwen Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Kaixuan Bao
- Human Phenome Institute, Fudan University, Shanghai, China
| | - Yiru Huang
- School of Life Sciences, Fudan University, Shanghai, China
| | - Ru Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- *Correspondence: Ting Yao, ; Ru Wang, ; Tiemin Liu,
| | - Tiemin Liu
- School of Life Sciences, Fudan University, Shanghai, China
- Human Phenome Institute, Fudan University, Shanghai, China
- State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
- *Correspondence: Ting Yao, ; Ru Wang, ; Tiemin Liu,
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10
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Hebras J, Marty V, Personnaz J, Mercier P, Krogh N, Nielsen H, Aguirrebengoa M, Seitz H, Pradere JP, Guiard BP, Cavaille J. Reassessment of the involvement of Snord115 in the serotonin 2c receptor pathway in a genetically relevant mouse model. eLife 2020; 9:60862. [PMID: 33016258 PMCID: PMC7673782 DOI: 10.7554/elife.60862] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
SNORD115 has been proposed to promote the activity of serotonin (HTR2C) receptor via its ability to base pair with its pre-mRNA and regulate alternative RNA splicing and/or A-to-I RNA editing. Because SNORD115 genes are deleted in most patients with the Prader-Willi syndrome (PWS), diminished HTR2C receptor activity could contribute to the impaired emotional response and/or compulsive overeating characteristic of this disease. In order to test this appealing but never demonstrated hypothesis in vivo, we created a CRISPR/Cas9-mediated Snord115 knockout mouse. Surprisingly, we uncovered only modest region-specific alterations in Htr2c RNA editing profiles, while Htr2c alternative RNA splicing was unchanged. These subtle changes, whose functional relevance remains uncertain, were not accompanied by any discernible defects in anxio-depressive-like phenotypes. Energy balance and eating behavior were also normal, even after exposure to high-fat diet. Our study raises questions concerning the physiological role of SNORD115, notably its involvement in behavioural disturbance associated with PWS.
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Affiliation(s)
- Jade Hebras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Virginie Marty
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Jean Personnaz
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Institut National de la Santé et de la Recherche Médicale (INSERM), France Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université de Toulouse Université Paul Sabatier, Toulouse, France
| | - Pascale Mercier
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Centre National de la Recherche Scientifique UMR5089, Toulouse, France
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Marion Aguirrebengoa
- LBCMCP, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, Toulouse, France
| | - Hervé Seitz
- IGH (CNRS and University of Montpellier), Montpellier, France
| | - Jean-Phillipe Pradere
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Institut National de la Santé et de la Recherche Médicale (INSERM), France Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université de Toulouse Université Paul Sabatier, Toulouse, France
| | - Bruno P Guiard
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique, Université de Toulouse, Toulouse, France
| | - Jérôme Cavaille
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
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11
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Chung MS, Langouët M, Chamberlain SJ, Carmichael GG. Prader-Willi syndrome: reflections on seminal studies and future therapies. Open Biol 2020; 10:200195. [PMID: 32961075 PMCID: PMC7536080 DOI: 10.1098/rsob.200195] [Citation(s) in RCA: 15] [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: 07/01/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
Prader-Willi syndrome (PWS) is caused by the loss of function of the paternally inherited 15q11-q13 locus. This region is governed by genomic imprinting, a phenomenon in which genes are expressed exclusively from one parental allele. The genomic imprinting of the 15q11-q13 locus is established in the germline and is largely controlled by a bipartite imprinting centre. One part, termed the Prader-Willi syndrome imprinting center (PWS-IC), comprises a CpG island that is unmethylated on the paternal allele and methylated on the maternal allele. The second part, termed the Angelman syndrome imprinting centre, is required to silence the PWS_IC in the maternal germline. The loss of the paternal contribution of the imprinted 15q11-q13 locus most frequently occurs owing to a large deletion of the entire imprinted region but can also occur through maternal uniparental disomy or an imprinting defect. While PWS is considered a contiguous gene syndrome based on large-deletion and uniparental disomy patients, the lack of expression of only non-coding RNA transcripts from the SNURF-SNRPN/SNHG14 may be the primary cause of PWS. Patients with small atypical deletions of the paternal SNORD116 cluster alone appear to have most of the PWS related clinical phenotypes. The loss of the maternal contribution of the 15q11-q13 locus causes a separate and distinct condition called Angelman syndrome. Importantly, while much has been learned about the regulation and expression of genes and transcripts deriving from the 15q11-q13 locus, there remains much to be learned about how these genes and transcripts contribute at the molecular level to the clinical traits and developmental aspects of PWS that have been observed.
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Affiliation(s)
| | | | | | - Gordon G. Carmichael
- Department of Genetics and Genome Sciences, UCONN Health, 400 Farmington Avenue, Farmington, CT 06030, USA
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12
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Bratkovič T, Božič J, Rogelj B. Functional diversity of small nucleolar RNAs. Nucleic Acids Res 2020; 48:1627-1651. [PMID: 31828325 PMCID: PMC7038934 DOI: 10.1093/nar/gkz1140] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/17/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022] Open
Abstract
Small nucleolar RNAs (snoRNAs) are short non-protein-coding RNAs with a long-recognized role in tuning ribosomal and spliceosomal function by guiding ribose methylation and pseudouridylation at targeted nucleotide residues of ribosomal and small nuclear RNAs, respectively. SnoRNAs are increasingly being implicated in regulation of new types of post-transcriptional processes, for example rRNA acetylation, modulation of splicing patterns, control of mRNA abundance and translational efficiency, or they themselves are processed to shorter stable RNA species that seem to be the principal or alternative bioactive isoform. Intriguingly, some display unusual cellular localization under exogenous stimuli, or tissue-specific distribution. Here, we discuss the new and unforeseen roles attributed to snoRNAs, focusing on the presumed mechanisms of action. Furthermore, we review the experimental approaches to study snoRNA function, including high resolution RNA:protein and RNA:RNA interaction mapping, techniques for analyzing modifications on targeted RNAs, and cellular and animal models used in snoRNA biology research.
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Affiliation(s)
- Tomaž Bratkovič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, SI1000 Ljubljana, Slovenia
| | - Janja Božič
- Jozef Stefan Institute, Department of Biotechnology, Jamova cesta 39, SI1000 Ljubljana, Slovenia.,Biomedical Research Institute BRIS, Puhova ulica 10, SI1000 Ljubljana, Slovenia
| | - Boris Rogelj
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, SI1000 Ljubljana, Slovenia.,Jozef Stefan Institute, Department of Biotechnology, Jamova cesta 39, SI1000 Ljubljana, Slovenia.,Biomedical Research Institute BRIS, Puhova ulica 10, SI1000 Ljubljana, Slovenia.,University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI1000 Ljubljana, Slovenia
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13
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Tanaka M, Watanabe Y. RNA Editing of Serotonin 2C Receptor and Alcohol Intake. Front Neurosci 2020; 13:1390. [PMID: 32009879 PMCID: PMC6971223 DOI: 10.3389/fnins.2019.01390] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/10/2019] [Indexed: 01/30/2023] Open
Abstract
Serotonin 2C receptor (5-HT2 CR) belongs to the superfamily of seven transmembrane domain receptors coupled to G proteins (GPCR). It is broadly distributed in the CNS and its expression is relatively high in the limbic system including the amygdala, nucleus accumbens (NAc), hippocampus, and hypothalamus. Based on its expression patterns and numerous pharmacological studies, 5-HT2 CR is thought to be involved in various brain functions including emotion, appetite, and motor behavior. Here, we review 5-HT2 CR and its relationship with alcohol intake with a particular focus on the involvement of 5-HT2 CR mRNA editing and its association with alcohol preference in mice. RNA editing is a post-transcriptional modification mechanism. In mammals, adenosine is converted to inosine by the deamination enzymes ADAR1 and ADAR2. 5-HT2 CR is the only GPCR subjected to RNA editing within the coding region. It has five editing sites in exon 5 that encode the second intracellular loop. Consequently, three amino acids residues (I156, N158, and I160) of the unedited receptor (INI) may be altered to differently edited isoforms, resulting in a change of receptor activity such as 5-HT potency and G-protein coupling. 5-HT2 CR in the NAc is involved in enhanced alcohol drinking after chronic alcohol exposure and alterations in 5-HT2 CR mRNA editing is important in determining the alcohol preference using different strains of mice and genetically modified mice. RNA editing of this receptor may participate in the development of alcoholism.
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Affiliation(s)
- Masaki Tanaka
- Department of Anatomy and Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yoshihisa Watanabe
- Department of Basic Geriatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
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14
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Latorre E, Mesonero JE, Harries LW. Alternative splicing in serotonergic system: Implications in neuropsychiatric disorders. J Psychopharmacol 2019; 33:1352-1363. [PMID: 31210090 DOI: 10.1177/0269881119856546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The serotonergic system is a key component of physiological brain function and is essential for proper neurological activity. Numerous neuropsychiatric disorders are associated with deregulation of the serotonergic system. Accordingly, many pharmacological treatments are focused on modulation of this system. While providing a promising line of therapeutic moderation, these approaches may be complicated due to the presence of alternative splicing events for key genes in this pathway. Alternative splicing is a co-transcriptional process by which different mRNA transcripts can be produced from the same gene. These different isoforms may have diverse activities and functions, and their relative balance is often critical for the maintenance of homeostasis. Alternative splicing greatly increases the production of proteins, augmenting cell plasticity, and provides an important control point for regulation of gene expression. AIM The objective of this narrative review is to discuss the potential impact of alternative splicing of different components of the serotonergic system and speculate on their involvement in several neuropsychiatric disorders. CONCLUSIONS The specific role of each isoform in disease and their relative activities in the signalling pathways involved are yet to be determined. We need to gain a better understanding of the basis of alternative isoforms of the serotonergic system in order to fully understand their impact and be able to develop new effective pharmacological isoform-specific targets.
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Affiliation(s)
- Eva Latorre
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
- Instituto Agroalimentario de Aragón - IA2 (Universidad de Zaragoza - CITA), Zaragoza, Spain
| | - Jose Emilio Mesonero
- Instituto Agroalimentario de Aragón - IA2 (Universidad de Zaragoza - CITA), Zaragoza, Spain
- Departamento Farmacología y Fisiología, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Universidad de Zaragoza, Zaragoza, Spain
| | - Lorna W Harries
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
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15
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Ectopic expression of Snord115 in choroid plexus interferes with editing but not splicing of 5-Ht2c receptor pre-mRNA in mice. Sci Rep 2019; 9:4300. [PMID: 30862860 PMCID: PMC6414643 DOI: 10.1038/s41598-019-39940-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/01/2019] [Indexed: 01/01/2023] Open
Abstract
Serotonin 5-HT2C receptor is a G-protein coupled excitatory receptor that regulates several biochemical pathways and has been implicated in obesity, mental state, sleep cycles, autism, neuropsychiatric disorders and neurodegenerative diseases. The activity of 5-HT2CR is regulated via alternative splicing and A to I editing of exon Vb of its pre-mRNA. Snord115 is a small nucleolar RNA that is expressed in mouse neurons and displays an 18-nucleotide base complementary to exon Vb of 5-HT2CR pre-mRNA. For almost two decades this putative guide element of Snord115 has wandered like a ghost through the literature in attempts to elucidate the biological significance of this complementarity. In mice, Snord115 is expressed in neurons and absent in the choroid plexus where, in contrast, 5-Ht2cr mRNA is highly abundant. Here we report the analysis of 5-Ht2cr pre-mRNA posttranscriptional processing via RNA deep sequencing in a mouse model that ectopically expresses Snord115 in the choroid plexus. In contrast to previous reports, our analysis demonstrated that Snord115 does not control alternative splicing of 5-Ht2cr pre-mRNA in vivo. We identified a modest, yet statistically significant reduction of 5-Ht2cr pre-mRNA A to I editing at the major A, B, C and D sites. We suggest that Snord115 and exon Vb of 5Ht2cr pre-mRNA form a double-stranded structure that is subject to ADAR-mediated A to I editing. To the best of our knowledge, this is the first comprehensive Snord115 gain-of-function analysis based on in vivo mouse models.
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16
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17
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Montes M, Sanford BL, Comiskey DF, Chandler DS. RNA Splicing and Disease: Animal Models to Therapies. Trends Genet 2019; 35:68-87. [PMID: 30466729 PMCID: PMC6339821 DOI: 10.1016/j.tig.2018.10.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/01/2018] [Accepted: 10/16/2018] [Indexed: 02/07/2023]
Abstract
Alternative splicing of pre-mRNA increases genetic diversity, and recent studies estimate that most human multiexon genes are alternatively spliced. If this process is not highly regulated and accurate, it leads to mis-splicing events, which may result in proteins with altered function. A growing body of work has implicated mis-splicing events in a range of diseases, including cancer, neurodegenerative diseases, and muscular dystrophies. Understanding the mechanisms that cause aberrant splicing events and how this leads to disease is vital for designing effective therapeutic strategies. In this review, we focus on advances in therapies targeting splicing, and highlight the animal models developed to recapitulate disease phenotypes as a model for testing these therapies.
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Affiliation(s)
- Matías Montes
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Brianne L Sanford
- Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Daniel F Comiskey
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Dawn S Chandler
- Molecular, Cellular, and Developmental Biology Graduate Program and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA; Center for Childhood Cancer and Blood Diseases, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
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18
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Welden JR, Zhang Z, Duncan MJ, Falaleeva M, Wells T, Stamm S. The posterior pituitary expresses the serotonin receptor 2C. Neurosci Lett 2018; 684:132-139. [PMID: 29969651 DOI: 10.1016/j.neulet.2018.06.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/19/2018] [Accepted: 06/27/2018] [Indexed: 10/28/2022]
Abstract
The serotonin receptor 2C (5HT2C) is an important drug target to treat obesity and depression. Its pre-mRNA undergoes alternative splicing, encoding a short RNA1 isoform that is localized intracellularly and a full-length isoform (RNA2) that can reach the cell membrane. These splicing isoforms are deregulated in Prader-Willi syndrome (PWS), due to the loss of a trans-acting regulatory RNA, SNORD115. Here we show that the 5HT2C mRNA is expressed in the posterior pituitary, suggesting that 5HT2C mRNA is generated in the hypothalamus and subsequently conveyed by axonal transport. In the pituitary, the ratio of 5HT2C isoforms is regulated by feeding, and can be manipulated using a splice-site changing oligonucleotide injected into the blood. The pituitary expression of the 5HT2C mRNA may constitute a previously unknown mechanism whereby serotonin in the circulation or drugs targeting the 5HT2C might induce side-effects. Finally, the deregulation of 5HT2C splicing isoforms in PWS could contribute to the known hormonal imbalances.
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Affiliation(s)
- Justin R Welden
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Zhaiyi Zhang
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Marilyn J Duncan
- Dept. of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, 40536, United States
| | - Marina Falaleeva
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, United Kingdom
| | - Stefan Stamm
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States.
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19
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Bratkovič T, Modic M, Camargo Ortega G, Drukker M, Rogelj B. Neuronal differentiation induces SNORD115 expression and is accompanied by post-transcriptional changes of serotonin receptor 2c mRNA. Sci Rep 2018; 8:5101. [PMID: 29572515 PMCID: PMC5865145 DOI: 10.1038/s41598-018-23293-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 03/09/2018] [Indexed: 12/13/2022] Open
Abstract
The serotonin neurotransmitter system is widespread in the brain and implicated in modulation of neuronal responses to other neurotransmitters. Among 14 serotonin receptor subtypes, 5-HT2cR plays a pivotal role in controlling neuronal network excitability. Serotonergic activity conveyed through receptor 5-HT2cR is regulated post-transcriptionally via two mechanisms, alternative splicing and A-to-I RNA editing. Brain-specific small nucleolar RNA SNORD115 harbours a phylogenetically conserved 18-nucleotide antisense element with perfect complementarity to the region of 5ht2c primary transcript that undergoes post-transcriptional changes. Previous 5ht2c minigene studies have implicated SNORD115 in fine-tuning of both post-transcriptional events. We monitored post-transcriptional changes of endogenous 5ht2c transcripts during neuronal differentiation. Both SNORD115 and 5ht2c were upregulated upon neuronal commitment. We detected increased 5ht2c alternative exon Vb inclusion already at the stage of neuronal progenitors, and more extensive A-to-I editing of non-targeted sites A and B compared to adjacent adenosines at sites E, C and D throughout differentiation. As the extent of editing is known to positively correlate with exon Vb usage while it reduces receptor functionality, our data support the model where SNORD115 directly promotes alternative exon inclusion without the requirement for conversion of key adenosines to inosines, thereby favouring production of full-length receptor isoforms with higher potency.
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Affiliation(s)
- Tomaž Bratkovič
- University of Ljubljana, Faculty of Pharmacy, Department of Pharmaceutical Biology, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Miha Modic
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Germán Camargo Ortega
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany.,Physiological Genomics, Biomedical Center, Ludwig-Maximilian University Munich, Munich, Germany
| | - Micha Drukker
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Boris Rogelj
- Jozef Stefan Institute, Department of Biotechnology, Jamova 39, 1000, Ljubljana, Slovenia. .,Biomedical Research Institute BRIS, Puhova 10, 1000, Ljubljana, Slovenia. .,University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000, Ljubljana, Slovenia.
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20
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Alternative mRNA Splicing in the Pathogenesis of Obesity. Int J Mol Sci 2018; 19:ijms19020632. [PMID: 29473878 PMCID: PMC5855854 DOI: 10.3390/ijms19020632] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/22/2022] Open
Abstract
Alternative mRNA splicing is an important mechanism in expansion of proteome diversity by production of multiple protein isoforms. However, emerging evidence indicates that only a limited number of annotated protein isoforms by alternative splicing are detected, and the coding sequence of alternative splice variants usually is only slightly different from that of the canonical sequence. Nevertheless, mis-splicing is associated with a large array of human diseases. Previous reviews mainly focused on hereditary and somatic mutations in cis-acting RNA sequence elements and trans-acting splicing factors. The importance of environmental perturbations contributed to mis-splicing is not assessed. As significant changes in exon skipping and splicing factors expression levels are observed with diet-induced obesity, this review focuses on several well-known alternatively spliced metabolic factors and discusses recent advances in the regulation of the expressions of splice variants under the pathophysiological conditions of obesity. The potential of targeting the alternative mRNA mis-splicing for obesity-associated diseases therapies will also be discussed.
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21
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Wyler SC, Lord CC, Lee S, Elmquist JK, Liu C. Serotonergic Control of Metabolic Homeostasis. Front Cell Neurosci 2017; 11:277. [PMID: 28979187 PMCID: PMC5611374 DOI: 10.3389/fncel.2017.00277] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 08/29/2017] [Indexed: 12/24/2022] Open
Abstract
New treatments are urgently needed to address the current epidemic of obesity and diabetes. Recent studies have highlighted multiple pathways whereby serotonin (5-HT) modulates energy homeostasis, leading to a renewed interest in the identification of 5-HT-based therapies for metabolic disease. This review aims to synthesize pharmacological and genetic studies that have found diverse functions of both central and peripheral 5-HT in the control of food intake, thermogenesis, and glucose and lipid metabolism. We also discuss the potential benefits of targeting the 5-HT system to combat metabolic disease.
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Affiliation(s)
- Steven C Wyler
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical CenterDallas, TX, United States
| | - Caleb C Lord
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical CenterDallas, TX, United States
| | - Syann Lee
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical CenterDallas, TX, United States
| | - Joel K Elmquist
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical CenterDallas, TX, United States.,Department of Pharmacology, UT Southwestern Medical CenterDallas, TX, United States
| | - Chen Liu
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical CenterDallas, TX, United States.,Department of Neuroscience, UT Southwestern Medical CenterDallas, TX, United States
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22
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Stamm S, Gruber SB, Rabchevsky AG, Emeson RB. The activity of the serotonin receptor 2C is regulated by alternative splicing. Hum Genet 2017; 136:1079-1091. [PMID: 28664341 PMCID: PMC5873585 DOI: 10.1007/s00439-017-1826-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/17/2017] [Indexed: 01/28/2023]
Abstract
The central nervous system-specific serotonin receptor 2C (5HT2C) controls key physiological functions, such as food intake, anxiety, and motoneuron activity. Its deregulation is involved in depression, suicidal behavior, and spasticity, making it the target for antipsychotic drugs, appetite controlling substances, and possibly anti-spasm agents. Through alternative pre-mRNA splicing and RNA editing, the 5HT2C gene generates at least 33 mRNA isoforms encoding 25 proteins. The 5HT2C is a G-protein coupled receptor that signals through phospholipase C, influencing the expression of immediate/early genes like c-fos. Most 5HT2C isoforms show constitutive activity, i.e., signal without ligand binding. The constitutive activity of 5HT2C is decreased by pre-mRNA editing as well as alternative pre-mRNA splicing, which generates a truncated isoform that switches off 5HT2C receptor activity through heterodimerization; showing that RNA processing regulates the constitutive activity of the 5HT2C system. RNA processing events influencing the constitutive activity target exon Vb that forms a stable double stranded RNA structure with its downstream intron. This structure can be targeted by small molecules and oligonucleotides that change exon Vb alternative splicing and influence 5HT2C signaling in mouse models, leading to a reduction in food intake. Thus, the 5HT2C system is a candidate for RNA therapy in multiple models of CNS disorders.
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Affiliation(s)
- Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
| | - Samuel B Gruber
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Alexander G Rabchevsky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA
| | - Ronald B Emeson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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23
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Isles AR. Htr2c Splice Variants and 5HT 2CR-Mediated Appetite. Trends Endocrinol Metab 2017; 28:542-544. [PMID: 28499663 DOI: 10.1016/j.tem.2017.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 10/19/2022]
Abstract
Serotonin 2C receptor (5HT2CR) exists as different isoforms as a result of alternate splicing. A truncated variant (5HT2CR-trunc) has no canonical receptor function and yet shows robust expression levels throughout the brain. Recent work has demonstrated the biochemical role of this isoform and how altering levels of 5HT2CR-trunc leads to changes in behaviour.
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Affiliation(s)
- Anthony R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Cardiff, UK.
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24
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Falaleeva M, Welden JR, Duncan MJ, Stamm S. C/D-box snoRNAs form methylating and non-methylating ribonucleoprotein complexes: Old dogs show new tricks. Bioessays 2017; 39:10.1002/bies.201600264. [PMID: 28505386 PMCID: PMC5586538 DOI: 10.1002/bies.201600264] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
C/D box snoRNAs (SNORDs) are an abundantly expressed class of short, non-coding RNAs that have been long known to perform 2'-O-methylation of rRNAs. However, approximately half of human SNORDs have no predictable rRNA targets, and numerous SNORDs have been associated with diseases that show no defects in rRNAs, among them Prader-Willi syndrome, Duplication 15q syndrome and cancer. This apparent discrepancy has been addressed by recent studies showing that SNORDs can act to regulate pre-mRNA alternative splicing, mRNA abundance, activate enzymes, and be processed into shorter ncRNAs resembling miRNAs and piRNAs. Furthermore, recent biochemical studies have shown that a given SNORD can form both methylating and non-methylating ribonucleoprotein complexes, providing an indication of the likely physical basis for such diverse new functions. Thus, SNORDs are more structurally and functionally diverse than previously thought, and their role in gene expression is under-appreciated. The action of SNORDs in non-methylating complexes can be substituted with oligonucleotides, allowing devising therapies for diseases like Prader-Willi syndrome.
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Affiliation(s)
- Marina Falaleeva
- University Kentucky, Institute for Biochemistry, Lexington, KY, USA
| | - Justin R. Welden
- University Kentucky, Institute for Biochemistry, Lexington, KY, USA
| | | | - Stefan Stamm
- University Kentucky, Institute for Biochemistry, Lexington, KY, USA
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25
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Cavaillé J. Box C/D small nucleolar RNA genes and the Prader-Willi syndrome: a complex interplay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28296064 DOI: 10.1002/wrna.1417] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 12/22/2022]
Abstract
The nucleolus of mammalian cells contains hundreds of box C/D small nucleolar RNAs (SNORDs). Through their ability to base pair with ribosomal RNA precursors, most play important roles in the synthesis and/or activity of ribosomes, either by guiding sequence-specific 2'-O-methylations or by facilitating RNA folding and cleavages. A growing number of SNORD genes with elusive functions have been discovered recently. Intriguingly, the vast majority of them are located in two large, imprinted gene clusters at human chromosome region 15q11q13 (the SNURF-SNRPN domain) and at 14q32 (the DLK1-DIO3 domain) where they are expressed, respectively, only from the paternally and maternally inherited alleles. These placental mammal-specific SNORD genes have many features of the canonical SNORDs that guide 2'-O-methylations, yet they lack obvious complementarity with ribosomal RNAs and, surprisingly, they are processed from large, tandemly repeated genes expressed preferentially in the brain. This review summarizes our understanding of the biology of these peculiar SNORD genes, focusing particularly on SNORD115 and SNORD116 in the SNURF-SNRPN domain. It examines the growing evidence that altered levels of these SNORDs and/or their host-gene transcripts may be a primary cause of Prader-Willi syndrome (PWS; a rare disorder characterized by overeating and obesity) as well as abnormalities in signaling through the 5-HT2C serotonin receptor. Finally, the hypothesis that PWS may be a ribosomopathy (ribosomal disease) is also discussed. WIREs RNA 2017, 8:e1417. doi: 10.1002/wrna.1417 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jérôme Cavaillé
- Laboratoire de Biologie Moléculaire Eucaryote, Université de Toulouse; UPS and CNRS, LMBE, Toulouse, France
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26
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Garfield AS, Davies JR, Burke LK, Furby HV, Wilkinson LS, Heisler LK, Isles AR. Increased alternate splicing of Htr2c in a mouse model for Prader-Willi syndrome leads disruption of 5HT 2C receptor mediated appetite. Mol Brain 2016; 9:95. [PMID: 27931246 PMCID: PMC5144496 DOI: 10.1186/s13041-016-0277-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/30/2016] [Indexed: 12/21/2022] Open
Abstract
Alternate splicing of serotonin (5-hydroxytryptamine; 5-HT) 2C receptor (5-HT2CR) pre-RNA is negatively regulated by the small nucleolar RNA, Snord115, loss of which is observed in nearly all individuals with Prader-Willi Syndrome (PWS), a multigenic disorder characterised by hyperphagia and obesity. Given the role of the 5-HT2CR in the regulation of ingestive behaviour we investigated the pathophysiological implications of Snord115 deficiency on 5-HT2CR regulated appetite in a genotypically relevant PWS mouse model (PWS-IC). Specifically, we demonstrate that loss of Snord115 expression is associated with increased levels of hypothalamic truncated 5-HT2CR pre-mRNA. The 5-HT2CR promotes appetite suppression via engagement of the central melanocortin system. Pro-opiomelancortin (Pomc) mRNA levels within the arcuate nucleus of the hypothalamus (ARC) were reduced in PWS-IC mice. We then went on to assess the functional consequences of these molecular changes, demonstrating that PWS-IC mice are unresponsive to an anorectic doses of a 5-HT2CR agonist and that this is associated with attenuated activation of POMC neurons within the ARC. These data provide new insight into the significance of Htr2c pre-mRNA processing to the physiological regulation of appetite and potentially the pathological manifestation of hyperphagia in PWS. Furthermore, these findings have translational relevance for individuals with PWS who may seek to control appetite with another 5-HT2CR agonist, the new obesity treatment lorcaserin.
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Affiliation(s)
- Alastair S Garfield
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.,Present address: Cardiovascular and Metabolic Disease, Pfizer, Cambridge, MA, 02139, USA
| | - Jennifer R Davies
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Luke K Burke
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Hannah V Furby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Lawrence S Wilkinson
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Lora K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Anthony R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK.
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27
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Zhang Z, Shen M, Gresch PJ, Ghamari-Langroudi M, Rabchevsky AG, Emeson RB, Stamm S. Oligonucleotide-induced alternative splicing of serotonin 2C receptor reduces food intake. EMBO Mol Med 2016; 8:878-94. [PMID: 27406820 PMCID: PMC4967942 DOI: 10.15252/emmm.201506030] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The serotonin 2C receptor regulates food uptake, and its activity is regulated by alternative pre-mRNA splicing. Alternative exon skipping is predicted to generate a truncated receptor protein isoform, whose existence was confirmed with a new antiserum. The truncated receptor sequesters the full-length receptor in intracellular membranes. We developed an oligonucleotide that promotes exon inclusion, which increases the ratio of the full-length to truncated receptor protein. Decreasing the amount of truncated receptor results in the accumulation of full-length, constitutively active receptor at the cell surface. After injection into the third ventricle of mice, the oligonucleotide accumulates in the arcuate nucleus, where it changes alternative splicing of the serotonin 2C receptor and increases pro-opiomelanocortin expression. Oligonucleotide injection reduced food intake in both wild-type and ob/ob mice. Unexpectedly, the oligonucleotide crossed the blood-brain barrier and its systemic delivery reduced food intake in wild-type mice. The physiological effect of the oligonucleotide suggests that a truncated splice variant regulates the activity of the serotonin 2C receptor, indicating that therapies aimed to change pre-mRNA processing could be useful to treat hyperphagia, characteristic for disorders like Prader-Willi syndrome.
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Affiliation(s)
- Zhaiyi Zhang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Paul J Gresch
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | | | | | - Ronald B Emeson
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
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