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Kumar M, Tyagi N, Faruq M. The molecular mechanisms of spinocerebellar ataxias for DNA repeat expansion in disease. Emerg Top Life Sci 2023; 7:289-312. [PMID: 37668011 DOI: 10.1042/etls20230013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/01/2023] [Accepted: 08/16/2023] [Indexed: 09/06/2023]
Abstract
Spinocerebellar ataxias (SCAs) are a heterogenous group of neurodegenerative disorders which commonly inherited in an autosomal dominant manner. They cause muscle incoordination due to degeneration of the cerebellum and other parts of nervous system. Out of all the characterized (>50) SCAs, 14 SCAs are caused due to microsatellite repeat expansion mutations. Repeat expansions can result in toxic protein gain-of-function, protein loss-of-function, and/or RNA gain-of-function effects. The location and the nature of mutation modulate the underlying disease pathophysiology resulting in varying disease manifestations. Potential toxic effects of these mutations likely affect key major cellular processes such as transcriptional regulation, mitochondrial functioning, ion channel dysfunction and synaptic transmission. Involvement of several common pathways suggests interlinked function of genes implicated in the disease pathogenesis. A better understanding of the shared and distinct molecular pathogenic mechanisms in these diseases is required to develop targeted therapeutic tools and interventions for disease management. The prime focus of this review is to elaborate on how expanded 'CAG' repeats contribute to the common modes of neurotoxicity and their possible therapeutic targets in management of such devastating disorders.
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Affiliation(s)
- Manish Kumar
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Nishu Tyagi
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Mohammed Faruq
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
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2
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Lau MHY, Wong CH, Chan HYE, Au-Yeung HY. Development of Fluorescent Turn-On Probes for CAG-RNA Repeats. BIOSENSORS 2022; 12:1080. [PMID: 36551047 PMCID: PMC9775061 DOI: 10.3390/bios12121080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Fluorescent sensing of nucleic acids is a highly sensitive and efficient bioanalytical method for their study in cellular processes, detection and diagnosis in related diseases. However, the design of small molecule fluorescent probes for the selective binding and detection of RNA of a specific sequence is very challenging because of their diverse, dynamic, and flexible structures. By modifying a bis(amidinium)-based small molecular binder that is known to selectively target RNA with CAG repeats using an environment-sensitive fluorophore, a turn-on fluorescent probe featuring aggregation-induced emission (AIE) is successfully developed in this proof-of-concept study. The probe (DB-TPE) exhibits a strong, 19-fold fluorescence enhancement upon binding to a short CAG RNA, and the binding and fluorescence response was found to be specific to the overall RNA secondary structure with A·A mismatches. These promising analytical performances suggest that the probe could be applied in pathological studies, disease progression monitoring, as well as diagnosis of related neurodegenerative diseases due to expanded CAG RNA repeats.
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Affiliation(s)
- Matthew Ho Yan Lau
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Chun-Ho Wong
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ho Yin Edwin Chan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong, China
- Nexus of Rare Neurodegenerative Diseases, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ho Yu Au-Yeung
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
- Nexus of Rare Neurodegenerative Diseases, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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3
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Peng SI, Leong LI, Sun JKL, Chen ZS, Chow HM, Chan HYE. A peptide inhibitor that rescues polyglutamine-induced synaptic defects and cell death through suppressing RNA and protein toxicities. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 29:102-115. [PMID: 35795484 PMCID: PMC9240964 DOI: 10.1016/j.omtn.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Polyglutamine (polyQ) diseases, including spinocerebellar ataxias and Huntington's disease, are progressive neurodegenerative disorders caused by CAG triplet-repeat expansion in the coding regions of disease-associated genes. In this study, we found that neurotoxic small CAG (sCAG) RNA species, microscopic Ataxin-2 CAG RNA foci, and protein aggregates exist as independent entities in cells. Synaptic defects and neurite outgrowth abnormalities were observed in mutant Ataxin-2-expressing mouse primary cortical neurons. We examined the suppression effects of the CAG RNA-binding peptide beta-structured inhibitor for neurodegenerative diseases (BIND) in mutant Ataxin-2-expressing mouse primary cortical neurons and found that both impaired synaptic phenotypes and neurite outgrowth defects were rescued. We further demonstrated that BIND rescued cell death through inhibiting sCAG RNA production, Ataxin-2 CAG RNA foci formation, and mutant Ataxin-2 protein translation. Interestingly, when the expanded CAG repeats in the mutant Ataxin-2 transcript was interrupted with the alternative glutamine codon CAA, BIND's inhibitory effect on mutant protein aggregation was lost. We previously demonstrated that BIND interacts physically and directly with expanded CAG RNA sequences. Our data provide evidence that the BIND peptide associates with transcribed mutant CAG RNA to inhibit the formation of toxic species, including sCAG RNA, RNA foci, and polyQ protein translation and aggregation.
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Affiliation(s)
- Shaohong Isaac Peng
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Lok I. Leong
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Jacquelyne Ka-Li Sun
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhefan Stephen Chen
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Hei-Man Chow
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Nexus of Rare Neurodegenerative Diseases, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Nexus of Rare Neurodegenerative Diseases, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
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4
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Fourier A, Quadrio I. Proteinopathies associated to repeat expansion disorders. J Neural Transm (Vienna) 2022; 129:173-185. [DOI: 10.1007/s00702-021-02454-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/13/2021] [Indexed: 12/11/2022]
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Ajjugal Y, Rathinavelan T. Conformational distortions induced by periodically recurring A…A in d(CAG).d(CAG) provide stereochemical rationale for the trapping of MSH2.MSH3 in polyQ disorders. Comput Struct Biotechnol J 2021; 19:4447-4455. [PMID: 34471491 PMCID: PMC8379282 DOI: 10.1016/j.csbj.2021.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 11/25/2022] Open
Abstract
CAG repeat instability causes a number of neurodegenerative disorders. The unusual hairpin stem structure formed by the CAG repeats in DNA traps the human mismatch repair MSH2.MSH3 (Mutsβ) complex. To understand the mechanism behind the abnormal binding of Mutsβ with the imperfect hairpin stem structure formed by CAG repeats, molecular dynamics simulations have been carried out for Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 (1 A…A mismatch) and Mutsβ-d(CAG)5.d(CAG)5 (5 mismatches, wherein, A…A occurs periodically) complexes. The interaction of MSH3 residue Tyr245 at the minor groove side of A…A, an essential interaction responsible for the recognition by Mutsβ, are retained in both the cases. Nevertheless, the periodic unwinding caused by the nonisostericity of A…A with the flanking canonical base pairs in d(CAG)5.d(CAG)5 distorts the regular B-form geometry. Such an unwinding exposes one of the A…A mismatches (that interacts with Tyr245) at the major groove side and also facilitates the on and off hydrogen bonding interaction with Lys546 sidechain (MSH2-domain-IV). In contrast, kinking of the DNA towards the major groove in Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 doesn’t facilitate such an exposure of the bases at the major groove. Further, the unwinding of the helix in d(CAG)5.d(CAG)5 enhances the tighter binding between MSH2-domain-I and d(CAG)5.d(CAG)5 at the major groove side as well as between MSH3-domain-I and MSH3-domain-IV. Markedly, such enhanced interactions are absent in Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 that has a single A…A mismatch. Thus, the above-mentioned enhancement in intra- and inter- molecular interactions in Mutsβ-d(CAG)5.d(CAG)5 provide the stereochemical rationale for the trapping of Mutsβ in CAG repeat expansion disorders.
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Affiliation(s)
- Yogeeshwar Ajjugal
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana State 502285, India
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6
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Jazurek-Ciesiolka M, Ciesiolka A, Komur AA, Urbanek-Trzeciak MO, Krzyzosiak WJ, Fiszer A. RAN Translation of the Expanded CAG Repeats in the SCA3 Disease Context. J Mol Biol 2020; 432:166699. [PMID: 33157084 DOI: 10.1016/j.jmb.2020.10.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 01/08/2023]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the ATXN3 gene encoding the ataxin-3 protein. Despite extensive research the exact pathogenic mechanisms of SCA3 are still not understood in depth. In the present study, to gain insight into the toxicity induced by the expanded CAG repeats in SCA3, we comprehensively investigated repeat-associated non-ATG (RAN) translation in various cellular models expressing translated or non-canonically translated ATXN3 sequences with an increasing number of CAG repeats. We demonstrate that two SCA3 RAN proteins, polyglutamine (polyQ) and polyalanine (polyA), are found only in the case of CAG repeats of pathogenic length. Despite having distinct cellular localization, RAN polyQ and RAN polyA proteins are very often coexpressed in the same cell, impairing nuclear integrity and inducing apoptosis. We provide for the first time mechanistic insights into SCA3 RAN translation indicating that ATXN3 sequences surrounding the repeat region have an impact on SCA3 RAN translation initiation and efficiency. We revealed that RAN translation of polyQ proteins starts at non-cognate codons upstream of the CAG repeats, whereas RAN polyA proteins are likely translated within repeats. Furthermore, integrated stress response activation enhances SCA3 RAN translation. Our findings suggest that the ATXN3 sequence context plays an important role in triggering SCA3 RAN translation and that SCA3 RAN proteins may cause cellular toxicity.
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Affiliation(s)
- Magdalena Jazurek-Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Adam Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Alicja A Komur
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Martyna O Urbanek-Trzeciak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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7
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Lee LKC, Leong LI, Liu Y, Luo M, Chan HYE, Choi CHJ. Preclinical Nanomedicines for Polyglutamine-Based Neurodegenerative Diseases. Mol Pharm 2020; 18:610-626. [PMID: 32584043 DOI: 10.1021/acs.molpharmaceut.0c00506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Polyglutamine (polyQ) diseases, such as Huntington's disease and several types of spinocerebellar ataxias, are dominantly inherited progressive neurodegenerative disorders and characterized by the presence of expanded CAG trinucleotide repeats in the respective disease locus of the patient genomes. Patients with polyQ diseases currently need to rely on symptom-relieving treatments because disease-modifying therapeutic interventions remain scarce. Many disease-modifying therapeutic agents are now under clinical testing for treating polyQ diseases, but their delivery to the brain is often too invasive (e.g., intracranial injection) or inefficient, owing to in vivo degradation and clearance by physiological barriers (e.g., oral and intravenous administration). Nanoparticles provide a feasible solution for improving drug delivery to the brain, as evidenced by an increasing number of preclinical studies that document the efficacy of nanomedicines for polyQ diseases over the past 5-6 years. In this review, we present the pathogenic mechanisms of polyQ diseases, the common animal models of polyQ diseases for evaluating the efficacy of nanomedicines, and the common administration routes for delivering nanoparticles to the brain. Next, we summarize the recent preclinical applications of nanomedicines for treating polyQ diseases and improving neurological conditions in vivo, placing emphasis on antisense oligonucleotides, small peptide inhibitors, and small molecules as the disease-modifying agents. We conclude with our perspectives of the burgeoning field of "nanomedicines for polyQ diseases", including the use of inorganic nanoparticles and potential drugs as next-generation nanomedicines, development of higher-order animal models of polyQ diseases, and importance of "brain-nano" interactions.
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Affiliation(s)
| | | | | | - Meihua Luo
- Monash Institute of Pharmaceutics Science, Monash University, Parkville, Victoria 3052, Australia
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8
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Mori S, Honda H, Ishii T, Yoshimura M, Sasagasako N, Suzuki SO, Taniwaki T, Iwaki T. Expanded polyglutamine impairs normal nuclear distribution of fused in sarcoma and poly (rC)‐binding protein 1 in Huntington's disease. Neuropathology 2019; 39:358-367. [DOI: 10.1111/neup.12600] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/25/2019] [Accepted: 08/08/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Shinichiro Mori
- Department of NeuropathologyGraduate School of Medical Sciences, Kyushu University Fukuoka Japan
- Department of Neurology, Division of Respirology, Neurology and Rheumatology, Department of MedicineKurume University School of Medicine Kurume Japan
| | - Hiroyuki Honda
- Department of NeuropathologyGraduate School of Medical Sciences, Kyushu University Fukuoka Japan
| | - Takashi Ishii
- Department of BiochemistryFukuoka Dental College Fukuoka Japan
| | - Motoi Yoshimura
- Department of NeuropathologyGraduate School of Medical Sciences, Kyushu University Fukuoka Japan
| | - Naokazu Sasagasako
- Department of NeurologyNeuro‐Muscular Center, National Omuta Hospital Omuta Japan
| | - Satoshi O. Suzuki
- Department of NeuropathologyGraduate School of Medical Sciences, Kyushu University Fukuoka Japan
| | - Takayuki Taniwaki
- Department of Neurology, Division of Respirology, Neurology and Rheumatology, Department of MedicineKurume University School of Medicine Kurume Japan
| | - Toru Iwaki
- Department of NeuropathologyGraduate School of Medical Sciences, Kyushu University Fukuoka Japan
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9
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Kreiner G, Sönmez A, Liss B, Parlato R. Integration of the Deacetylase SIRT1 in the Response to Nucleolar Stress: Metabolic Implications for Neurodegenerative Diseases. Front Mol Neurosci 2019; 12:106. [PMID: 31110473 PMCID: PMC6499230 DOI: 10.3389/fnmol.2019.00106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/09/2019] [Indexed: 01/10/2023] Open
Abstract
Understanding underlying mechanisms of neurodegenerative diseases is fundamental to develop effective therapeutic intervention. Yet they remain largely elusive, but metabolic, and transcriptional dysregulation are common events. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent lysine deacetylase, regulating transcription, and critical for the cellular adaptations to metabolic stress. SIRT1 regulates the transcription of ribosomal RNA (rRNA), connecting the energetic state with cell growth and function. The activity of the transcription initiation factor-IA (TIF-IA) is important for the transcriptional regulation of ribosomal DNA (rDNA) genes in the nucleolus, and is also sensitive to changes in the cellular energetic state. Moreover, TIF-IA is responsive to nutrient-deprivation, neurotrophic stimulation, and oxidative stress. Hence, both SIRT1 and TIF-IA connect changes in cellular stress with transcriptional regulation and metabolic adaptation. Moreover, they finely tune the activity of the transcription factor p53, maintain mitochondrial function, and oxidative stress responses. Here we reviewed and discussed evidence that SIRT1 and TIF-IA are regulated by shared pathways and their activities preserve neuronal homeostasis in response to metabolic stressors. We provide evidence that loss of rDNA transcription due to altered TIF-IA function alters SIRT1 expression and propose a model of interdependent feedback mechanisms. An imbalance of this signaling might be a critical common event in neurodegenerative diseases. In conclusion, we provide a novel perspective for the prediction of the therapeutic benefits of the modulation of SIRT1- and nucleolar-dependent pathways in metabolic and neurodegenerative diseases.
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Affiliation(s)
- Grzegorz Kreiner
- Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Aynur Sönmez
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.,New College, Oxford University, Oxford, United Kingdom
| | - Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.,Department of Medical Cell Biology, Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany
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10
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Zhang Q, An Y, Chen ZS, Koon AC, Lau KF, Ngo JCK, Chan HYE. A Peptidylic Inhibitor for Neutralizing r(GGGGCC) exp-Associated Neurodegeneration in C9ALS-FTD. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 16:172-185. [PMID: 30889483 PMCID: PMC6424097 DOI: 10.1016/j.omtn.2019.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 02/06/2023]
Abstract
One drug, two diseases is a rare and economical therapeutic strategy that is highly desirable in the pharmaceutical industry. We previously reported a 21-amino acid peptide named beta-structured inhibitor for neurodegenerative diseases (BIND) that can effectively inhibit expanded CAG trinucleotide toxicity in polyglutamine (polyQ) diseases. Here we report that BIND also effectively inhibits GGGGCC repeat-mediated neurodegeneration in vitro and in vivo. When fused with a cell-penetrating peptide derived from the transactivator of transcription (TAT) protein of the HIV, TAT-BIND reduces cell death, formation of GGGGCC RNA foci, and levels of poly-GR, poly-GA, and poly-GP dipeptide proteins in cell models of C9ORF72-associated amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS-FTD). We showed that TAT-BIND disrupts the interaction between GGGGCC RNA and nucleolin protein, restores rRNA maturation, and inhibits mislocalization of nucleolin and B23, which eventually suppresses nucleolar stress in C9ALS-FTD. In a Drosophila model of C9ALS-FTD, TAT-BIND suppresses retinal degeneration, rescues climbing ability, and extends the lifespan of flies. In contrast, TAT-BIND has no effect on UAS-poly-glycine-arginine (poly-GR)100-expressing flies, which generate only poly-GR protein toxicity, indicating BIND ameliorates toxicity in C9ALS-FTD models via a r(GGGGCC)exp-dependent inhibitory mechanism. Our findings demonstrated that, apart from being a potential therapeutic for polyQ diseases, BIND is also a potent peptidylic inhibitor that suppresses expanded GGGGCC RNA-mediated neurodegeneration, highlighting its potential application in C9ALS-FTD treatment.
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Affiliation(s)
- Qian Zhang
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ying An
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhefan Stephen Chen
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Alex Chun Koon
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Kwok-Fai Lau
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.
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Lo Piccolo L. Drosophila as a Model to Gain Insight into the Role of lncRNAs in Neurological Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1076:119-146. [PMID: 29951818 DOI: 10.1007/978-981-13-0529-0_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is now clear that the majority of transcription in humans results in the production of long non-protein-coding RNAs (lncRNAs) with a variable length spanning from 200 bp up to several kilobases. To date, we have a limited understanding of the lncRNA function, but a huge number of evidences have suggested that lncRNAs represent an outstanding asset for cells. In particular, temporal and spatial expression of lncRNAs appears to be important for proper neurological functioning. Stunningly, abnormal lncRNA function has been found as being critical for the onset of neurological disorders. This chapter focus on the lncRNAs with a role in diseases affecting the central nervous system with particular regard for the lncRNAs causing those neurodegenerative diseases that exhibit dementia and/or motor dysfunctions. A specific section will be dedicated to the human neuronal lncRNAs that have been modelled in Drosophila. Finally, even if only few examples have been reported so far, an overview of the Drosophila lncRNAs with neurological functions will be also included in this chapter.
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Affiliation(s)
- Luca Lo Piccolo
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine 2-2 Yamadaoka, Suita Osaka, 565-0871, Japan.
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12
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Nizhnikov AA, Antonets KS, Bondarev SA, Inge-Vechtomov SG, Derkatch IL. Prions, amyloids, and RNA: Pieces of a puzzle. Prion 2017; 10:182-206. [PMID: 27248002 DOI: 10.1080/19336896.2016.1181253] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Amyloids are protein aggregates consisting of fibrils rich in β-sheets. Growth of amyloid fibrils occurs by the addition of protein molecules to the tip of an aggregate with a concurrent change of a conformation. Thus, amyloids are self-propagating protein conformations. In certain cases these conformations are transmissible / infectious; they are known as prions. Initially, amyloids were discovered as pathological extracellular deposits occurring in different tissues and organs. To date, amyloids and prions have been associated with over 30 incurable diseases in humans and animals. However, a number of recent studies demonstrate that amyloids are also functionally involved in a variety of biological processes, from biofilm formation by bacteria, to long-term memory in animals. Interestingly, amyloid-forming proteins are highly overrepresented among cellular factors engaged in all stages of mRNA life cycle: from transcription and translation, to storage and degradation. Here we review rapidly accumulating data on functional and pathogenic amyloids associated with mRNA processing, and discuss possible significance of prion and amyloid networks in the modulation of key cellular functions.
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Affiliation(s)
- Anton A Nizhnikov
- a Dept. of Genetics and Biotechnology , St. Petersburg State University , St. Petersburg , Russia.,b Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg Branch , St. Petersburg , Russia.,c All-Russia Research Institute for Agricultural Microbiology , St. Petersburg , Russia
| | - Kirill S Antonets
- a Dept. of Genetics and Biotechnology , St. Petersburg State University , St. Petersburg , Russia.,b Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg Branch , St. Petersburg , Russia
| | - Stanislav A Bondarev
- a Dept. of Genetics and Biotechnology , St. Petersburg State University , St. Petersburg , Russia
| | - Sergey G Inge-Vechtomov
- a Dept. of Genetics and Biotechnology , St. Petersburg State University , St. Petersburg , Russia.,b Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg Branch , St. Petersburg , Russia
| | - Irina L Derkatch
- d Department of Neuroscience , College of Physicians and Surgeons of Columbia University, Columbia University , New York , NY , USA
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Guo P, Chan HYE, Lam SL. Conformational flexibility in the RNA stem-loop structures formed by CAG repeats. FEBS Lett 2017; 591:1752-1760. [PMID: 28488797 DOI: 10.1002/1873-3468.12672] [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: 12/13/2016] [Revised: 02/28/2017] [Accepted: 05/05/2017] [Indexed: 11/11/2022]
Abstract
The expansion of CAG repeats has been found to be associated with at least nine human genetic disorders. In these disorders, the full-length expanded CAG RNA transcripts are cleaved into small CAG-repeated RNAs which are cytotoxic and known to be capable of forming hairpins. To better understand the RNA pathogenic mechanism, in this study we have performed high-resolution nuclear magnetic resonance structural investigations on the RNA hairpins formed by CAG repeats. Our results show the formation of a type III AGCA tetraloop and reveal the effect of stem rigidity on the loop conformational flexibility.
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Affiliation(s)
- Pei Guo
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Ho Yin Edwin Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.,Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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14
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Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
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15
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Jaworska E, Kozlowska E, Switonski PM, Krzyzosiak WJ. Modeling simple repeat expansion diseases with iPSC technology. Cell Mol Life Sci 2016; 73:4085-100. [PMID: 27261369 PMCID: PMC11108530 DOI: 10.1007/s00018-016-2284-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 12/20/2022]
Abstract
A number of human genetic disorders, including Huntington's disease, myotonic dystrophy type 1, C9ORF72 form of amyotrophic lateral sclerosis and several spinocerebellar ataxias, are caused by the expansion of various microsatellite sequences in single implicated genes. The neurodegenerative and neuromuscular nature of the repeat expansion disorders considerably limits the access of researchers to appropriate cellular models of these diseases. This limitation, however, can be overcome by the application of induced pluripotent stem cell (iPSC) technology. In this paper, we review the current knowledge on the modeling of repeat expansion diseases with human iPSCs and iPSC-derived cells, focusing on the disease phenotypes recapitulated in these models. In subsequent sections, we provide basic practical knowledge regarding iPSC generation, characterization and differentiation into neurons. We also cover disease modeling in iPSCs, neuronal stem cells and specialized neuronal cultures. Furthermore, we also summarize the therapeutic potential of iPSC technology in repeat expansion diseases.
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Affiliation(s)
- Edyta Jaworska
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704, Poznan, Poland
| | - Emilia Kozlowska
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704, Poznan, Poland
| | - Pawel M Switonski
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704, Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704, Poznan, Poland.
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16
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Shimada MK, Sanbonmatsu R, Yamaguchi-Kabata Y, Yamasaki C, Suzuki Y, Chakraborty R, Gojobori T, Imanishi T. Selection pressure on human STR loci and its relevance in repeat expansion disease. Mol Genet Genomics 2016; 291:1851-69. [PMID: 27290643 DOI: 10.1007/s00438-016-1219-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 05/21/2016] [Indexed: 12/30/2022]
Abstract
Short Tandem Repeats (STRs) comprise repeats of one to several base pairs. Because of the high mutability due to strand slippage during DNA synthesis, rapid evolutionary change in the number of repeating units directly shapes the range of repeat-number variation according to selection pressure. However, the remaining questions include: Why are STRs causing repeat expansion diseases maintained in the human population; and why are these limited to neurodegenerative diseases? By evaluating the genome-wide selection pressure on STRs using the database we constructed, we identified two different patterns of relationship in repeat-number polymorphisms between DNA and amino-acid sequences, although both patterns are evolutionary consequences of avoiding the formation of harmful long STRs. First, a mixture of degenerate codons is represented in poly-proline (poly-P) repeats. Second, long poly-glutamine (poly-Q) repeats are favored at the protein level; however, at the DNA level, STRs encoding long poly-Qs are frequently divided by synonymous SNPs. Furthermore, significant enrichments of apoptosis and neurodevelopment were biological processes found specifically in genes encoding poly-Qs with repeat polymorphism. This suggests the existence of a specific molecular function for polymorphic and/or long poly-Q stretches. Given that the poly-Qs causing expansion diseases were longer than other poly-Qs, even in healthy subjects, our results indicate that the evolutionary benefits of long and/or polymorphic poly-Q stretches outweigh the risks of long CAG repeats predisposing to pathological hyper-expansions. Molecular pathways in neurodevelopment requiring long and polymorphic poly-Q stretches may provide a clue to understanding why poly-Q expansion diseases are limited to neurodegenerative diseases.
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Affiliation(s)
- Makoto K Shimada
- Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan. .,National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan. .,Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan.
| | - Ryoko Sanbonmatsu
- Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan
| | - Yumi Yamaguchi-Kabata
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan.,Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8573, Japan
| | - Chisato Yamasaki
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan.,Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan
| | - Yoshiyuki Suzuki
- Graduate School of Natural Sciences, Nagoya City University, 1 Yamanohata, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8501, Japan
| | - Ranajit Chakraborty
- Health Science Center, University of North Texas, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Takashi Gojobori
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan.,Computational Bioscience Research Center, King Abdullah University of Science and Technology, Ibn Al-Haytham Building (West), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Tadashi Imanishi
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan.,Department of Molecular Life Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1193, Japan
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17
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Urbanek MO, Jazurek M, Switonski PM, Figura G, Krzyzosiak WJ. Nuclear speckles are detention centers for transcripts containing expanded CAG repeats. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1513-20. [PMID: 27239700 DOI: 10.1016/j.bbadis.2016.05.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/18/2016] [Accepted: 05/26/2016] [Indexed: 12/13/2022]
Abstract
The human genetic disorders caused by CAG repeat expansions in the translated sequences of various genes are called polyglutamine (polyQ) diseases because of the cellular "toxicity" of the mutant proteins. The contribution of mutant transcripts to the pathogenesis of these diseases is supported by several observations obtained from cellular models of these disorders. Here, we show that the common feature of cell lines modeling polyQ diseases is the formation of nuclear CAG RNA foci. We performed qualitative and quantitative analyses of these foci in numerous cellular models endogenously and exogenously expressing mutant transcripts by fluorescence in situ hybridization (FISH). We compared the CAG RNA foci of polyQ diseases with the CUG foci of myotonic dystrophy type 1 and found substantial differences in their number and morphology. Smaller differences within the polyQ disease group were also revealed and included a positive correlation between the foci number and the CAG repeat length. We show that expanded CAA repeats, also encoding glutamine, did not trigger RNA foci formation and foci formation is independent of the presence of mutant polyglutamine protein. Using FISH combined with immunofluorescence, we demonstrated partial co-localization of CAG repeat foci with MBNL1 alternative splicing factor, which explains the mild deregulation of MBNL1-dependent genes. We also showed that foci reside within nuclear speckles in diverse cell types: fibroblasts, lymphoblasts, iPS cells and neuronal progenitors and remain dependent on integrity of these nuclear structures.
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Affiliation(s)
- Martyna O Urbanek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Magdalena Jazurek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Pawel M Switonski
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Grzegorz Figura
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
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18
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Zhang Q, Tsoi H, Peng S, Li PP, Lau KF, Rudnicki DD, Ngo JCK, Chan HYE. Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila. Dis Model Mech 2016; 9:321-34. [PMID: 26839389 PMCID: PMC4833327 DOI: 10.1242/dmm.022350] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/27/2016] [Indexed: 02/03/2023] Open
Abstract
Polyglutamine (polyQ) diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1), a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration.
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Affiliation(s)
- Qian Zhang
- Laboratory of Drosophila Research, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Ho Tsoi
- Laboratory of Drosophila Research, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Shaohong Peng
- Laboratory of Drosophila Research, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Pan P Li
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Program of Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Kwok-Fai Lau
- Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Cell and Molecular Biology Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Molecular Biotechnology Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Dobrila D Rudnicki
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Program of Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jacky Chi-Ki Ngo
- Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Cell and Molecular Biology Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila Research, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Biochemistry Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Cell and Molecular Biology Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China Molecular Biotechnology Program, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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19
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Loureiro JR, Oliveira CL, Silveira I. Unstable repeat expansions in neurodegenerative diseases: nucleocytoplasmic transport emerges on the scene. Neurobiol Aging 2015; 39:174-83. [PMID: 26923414 DOI: 10.1016/j.neurobiolaging.2015.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/07/2015] [Accepted: 12/15/2015] [Indexed: 12/12/2022]
Abstract
An astonishing number of neurological diseases result from expansion of unstable repetitive sequences causing alterations in key neuronal processes. Some are progressive late-onset conditions related to aging, such as the spinocerebellar ataxias. In several of these pathologies, the expanded repeat is transcribed, producing an expanded RNA repeat that causes neurodegeneration by a complex mechanism, comprising 3 main pathways. These include (1) accumulation in the nucleus of RNA foci, resulting from sequestration of RNA-binding proteins functioning in important neuronal cascades; (2) decrease in availability of RNA-binding proteins, such as splicing factors, causing alternative splicing misregulation with imbalance in the expression ratio of neuronal isoforms; and (3) generation of neurotoxic peptides, produced from repeat-associated non-ATG-initiated translation across the RNA repeat, in all reading frames. Recently, 2 pathologies characterized by impaired motor function, cognitive decline, or/and degeneration of motor neurons have been found that have broaden our understanding of these diseases. Moreover, the finding of compromised nucleocytoplasmic transport opens new avenues for research. This review will cover the amazing progress regarding these conditions.
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Affiliation(s)
- Joana R Loureiro
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal
| | - Claudia L Oliveira
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal
| | - Isabel Silveira
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal.
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20
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Urbanek MO, Krzyzosiak WJ. RNA FISH for detecting expanded repeats in human diseases. Methods 2015; 98:115-123. [PMID: 26615955 DOI: 10.1016/j.ymeth.2015.11.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/18/2015] [Accepted: 11/21/2015] [Indexed: 12/14/2022] Open
Abstract
RNA fluorescence in situ hybridization (FISH) is a widely used technique for detecting transcripts in fixed cells and tissues. Many variants of RNA FISH have been proposed to increase signal strength, resolution and target specificity. The current variants of this technique facilitate the detection of the subcellular localization of transcripts at a single molecule level. Among the applications of RNA FISH are studies on nuclear RNA foci in diseases resulting from the expansion of tri-, tetra-, penta- and hexanucleotide repeats present in different single genes. The partial or complete retention of mutant transcripts forming RNA aggregates within the nucleoplasm has been shown in multiple cellular disease models and in the tissues of patients affected with these atypical mutations. Relevant diseases include, among others, myotonic dystrophy type 1 (DM1) with CUG repeats, Huntington's disease (HD) and spinocerebellar ataxia type 3 (SCA3) with CAG repeats, fragile X-associated tremor/ataxia syndrome (FXTAS) with CGG repeats, myotonic dystrophy type 2 (DM2) with CCUG repeats, amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) with GGGGCC repeats and spinocerebellar ataxia type 32 (SCA32) with GGCCUG. In this article, we summarize the results obtained with FISH to examine RNA nuclear inclusions. We provide a detailed protocol for detecting RNAs containing expanded CAG and CUG repeats in different cellular models, including fibroblasts, lymphoblasts, induced pluripotent stem cells and murine and human neuronal progenitors. We also present the results of the first single-molecule FISH application in a cellular model of polyglutamine disease.
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Affiliation(s)
- Martyna O Urbanek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland.
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21
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Nataf S, Pays L. Gene co-expression analysis unravels a link between C9orf72 and RNA metabolism in myeloid cells. Acta Neuropathol Commun 2015; 3:64. [PMID: 26472214 PMCID: PMC4608290 DOI: 10.1186/s40478-015-0242-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/07/2015] [Indexed: 11/18/2022] Open
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