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Tandon S, Aggarwal P, Sarkar S. Polyglutamine disorders: Pathogenesis and potential drug interventions. Life Sci 2024; 344:122562. [PMID: 38492921 DOI: 10.1016/j.lfs.2024.122562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/27/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
Polyglutamine/poly(Q) diseases are a group nine hereditary neurodegenerative disorders caused due to abnormally expanded stretches of CAG trinucleotide in functionally distinct genes. All human poly(Q) diseases are characterized by the formation of microscopically discernable poly(Q) positive aggregates, the inclusion bodies. These toxic inclusion bodies are responsible for the impairment of several cellular pathways such as autophagy, transcription, cell death, etc., that culminate in disease manifestation. Although, these diseases remain largely without treatment, extensive research has generated mounting evidences that various events of poly(Q) pathogenesis can be developed as potential drug targets. The present review article briefly discusses the key events of disease pathogenesis, model system-based investigations that support the development of effective therapeutic interventions against pathogenesis of human poly(Q) disorders, and a comprehensive list of pharmacological and bioactive compounds that have been experimentally shown to alleviate poly(Q)-mediated neurotoxicity. Interestingly, due to the common cause of pathogenesis, all poly(Q) diseases share etiology, thus, findings from one disease can be potentially extrapolated to other poly(Q) diseases as well.
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Affiliation(s)
- Shweta Tandon
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Prerna Aggarwal
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
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2
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Bennett CL, Dastidar S, Arnold FJ, McKinstry SU, Stockford C, Freibaum BD, Sopher BL, Wu M, Seidner G, Joiner W, Taylor JP, West RJH, La Spada AR. Senataxin helicase, the causal gene defect in ALS4, is a significant modifier of C9orf72 ALS G4C2 and arginine-containing dipeptide repeat toxicity. Acta Neuropathol Commun 2023; 11:164. [PMID: 37845749 PMCID: PMC10580588 DOI: 10.1186/s40478-023-01665-z] [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: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023] Open
Abstract
Identifying genetic modifiers of familial amyotrophic lateral sclerosis (ALS) may reveal targets for therapeutic modulation with potential application to sporadic ALS. GGGGCC (G4C2) repeat expansions in the C9orf72 gene underlie the most common form of familial ALS, and generate toxic arginine-containing dipeptide repeats (DPRs), which interfere with membraneless organelles, such as the nucleolus. Here we considered senataxin (SETX), the genetic cause of ALS4, as a modifier of C9orf72 ALS, because SETX is a nuclear helicase that may regulate RNA-protein interactions involved in ALS dysfunction. After documenting that decreased SETX expression enhances arginine-containing DPR toxicity and C9orf72 repeat expansion toxicity in HEK293 cells and primary neurons, we generated SETX fly lines and evaluated the effect of SETX in flies expressing either (G4C2)58 repeats or glycine-arginine-50 [GR(50)] DPRs. We observed dramatic suppression of disease phenotypes in (G4C2)58 and GR(50) Drosophila models, and detected a striking relocalization of GR(50) out of the nucleolus in flies co-expressing SETX. Next-generation GR(1000) fly models, that show age-related motor deficits in climbing and movement assays, were similarly rescued with SETX co-expression. We noted that the physical interaction between SETX and arginine-containing DPRs is partially RNA-dependent. Finally, we directly assessed the nucleolus in cells expressing GR-DPRs, confirmed reduced mobility of proteins trafficking to the nucleolus upon GR-DPR expression, and found that SETX dosage modulated nucleolus liquidity in GR-DPR-expressing cells and motor neurons. These findings reveal a hitherto unknown connection between SETX function and cellular processes contributing to neuron demise in the most common form of familial ALS.
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Affiliation(s)
- Craig L Bennett
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Somasish Dastidar
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
- Center for Molecular Neurosciences, Kasturba Medical College, Manipal, 576104, India
| | - Frederick J Arnold
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
| | - Spencer U McKinstry
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Cameron Stockford
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA
| | - Brian D Freibaum
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Bryce L Sopher
- Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, 98195, USA
| | - Meilin Wu
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Glen Seidner
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - William Joiner
- Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, 98195, USA
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA
| | - Ryan J H West
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK.
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Albert R La Spada
- Departments of Pathology, Laboratory Medicine, Neurology, and Biological Chemistry, UCI Center for Neurotherapeutics, University of California Irvine School of Medicine, Irvine, CA, 92697, USA.
- Department of Neurology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Neurobiology and Behavior, University of California Irvine School of Biosciences, Irvine, CA, 92697, USA.
- UCI Center for Neurotherapeutics, University of California Irvine, Irvine, CA, 92697, USA.
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Khani M, Nafissi S, Shamshiri H, Moazzeni H, Taheri H, Sadeghi M, Salehi N, Chitsazian F, Elahi E. Identification of UBA1 as the causative gene of an X-linked non-Kennedy SBMA. Eur J Neurol 2022; 29:3556-3563. [PMID: 35996994 DOI: 10.1111/ene.15528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/18/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Spinal-bulbar muscular atrophy (SBMA; Kennedy's Disease) is a motor neuron disease (MND). Kennedy's Disease is nearly exclusively caused by mutations in the androgen receptor encoding gene (AR). We report results of studies aimed at identification of the genetic cause of a disease that best approximates SBMA in a pedigree (four patients) without mutations in AR. METHODS Clinical investigations included thorough neurologic and non-neurologic examinations and testings. Genetic analysis was performed by exome sequencing using standard protocols. UBA1 mutations were modeled on the crystal structure of UBA1. RESULTS The clinical features of the patients are described in detail. A missense mutation in UBA1 (c.T1499C; p.Ile500Thr) was identified as the probable cause of the non-Kennedy SBMA in the pedigree. Like AR, UBA1 is positioned on Chromosome X. UBA1 is a highly conserved gene. It encodes ubiquitin like modifier activating enzyme 1 (UBA1) which is the major E1 enzyme of the ubiquitin-proteasome system. Interestingly, UBA1 mutations can also cause infantile-onset X-linked spinal muscular atrophy (XL-SMA). The mutation identified here and the XL-SMA causative mutations were shown to affect amino acids positioned in the vicinity of UBA1's ATP binding site and to cause structural changes. CONCLUSION UBA1 was identified as a novel SBMA causative gene. The gene affects protein homeostasis which is one of most important components of the pathology of neurodegeneration. The contribution of this same gene to the etiology of XL-SMA is discussed.
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Affiliation(s)
- Marzieh Khani
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Shahriar Nafissi
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hosein Shamshiri
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hanieh Taheri
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Mehdi Sadeghi
- National Institute for Genetic Engineering and Biotechnology, Tehran, Iran
| | - Najmeh Salehi
- School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | | | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
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Ogura Y, Sahashi K, Hirunagi T, Iida M, Miyata T, Katsuno M. Mid1 is associated with androgen-dependent axonal vulnerability of motor neurons in spinal and bulbar muscular atrophy. Cell Death Dis 2022; 13:601. [PMID: 35821212 PMCID: PMC9276699 DOI: 10.1038/s41419-022-05001-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/31/2022] [Accepted: 06/07/2022] [Indexed: 01/21/2023]
Abstract
Spinal and bulbar muscular atrophy (SBMA) is an adult-onset hereditary neurodegenerative disease caused by the expansions of CAG repeats in the androgen receptor (AR) gene. Androgen-dependent nuclear accumulation of pathogenic AR protein causes degeneration of lower motor neurons, leading to progressive muscle weakness and atrophy. While the successful induction of SBMA-like pathology has been achieved in mouse models, mechanisms underlying motor neuron vulnerability remain unclear. In the present study, we performed a transcriptome-based screening for genes expressed exclusively in motor neurons and dysregulated in the spinal cord of SBMA mice. We found upregulation of Mid1 encoding a microtubule-associated RNA binding protein which facilitates the translation of CAG-expanded mRNAs. Based on the finding that lower motor neurons begin expressing Mid1 during embryonic stages, we developed an organotypic slice culture system of the spinal cord obtained from SBMA mouse fetuses to study the pathogenic role of Mid1 in SBMA motor neurons. Impairment of axonal regeneration arose in the spinal cord culture in SBMA mice in an androgen-dependent manner, but not in mice with non-CAG-expanded AR, and was either exacerbated or ameliorated by Mid1 overexpression or knockdown, respectively. Hence, an early Mid1 expression confers vulnerability to motor neurons, at least by inducing axonogenesis defects, in SBMA.
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Affiliation(s)
- Yosuke Ogura
- grid.27476.300000 0001 0943 978XDepartment of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kentaro Sahashi
- grid.27476.300000 0001 0943 978XDepartment of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomoki Hirunagi
- grid.27476.300000 0001 0943 978XDepartment of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Madoka Iida
- grid.27476.300000 0001 0943 978XDepartment of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takaki Miyata
- grid.27476.300000 0001 0943 978XDepartment of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahisa Katsuno
- grid.27476.300000 0001 0943 978XDepartment of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan ,grid.27476.300000 0001 0943 978XDepartment of Clinical Research Education, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Schellino R, Boido M, Vercelli A. JNK Signaling Pathway Involvement in Spinal Cord Neuron Development and Death. Cells 2019; 8:E1576. [PMID: 31817379 PMCID: PMC6953032 DOI: 10.3390/cells8121576] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022] Open
Abstract
The c-Jun NH2-terminal protein kinase (JNK) is a Janus-faced kinase, which, in the nervous system, plays important roles in a broad range of physiological and pathological processes. Three genes, encoding for 10 JNK isoforms, have been identified: jnk1, jnk2, and jnk3. In the developing spinal cord, JNK proteins control neuronal polarity, axon growth/pathfinding, and programmed cell death; in adulthood they can drive degeneration and regeneration, after pathological insults. Indeed, recent studies have highlighted a role for JNK in motor neuron (MN) diseases, such as amyotrophic lateral sclerosis and spinal muscular atrophy. In this review we discuss how JNK-dependent signaling regulates apparently contradictory functions in the spinal cord, in both the developmental and adult stages. In addition, we examine the evidence that the specific targeting of JNK signaling pathway may represent a promising therapeutic strategy for the treatment of MN diseases.
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Affiliation(s)
- Roberta Schellino
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
| | - Marina Boido
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
- National Institute of Neuroscience (INN), 10125 Turin, Italy
| | - Alessandro Vercelli
- Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano (TO), Italy
- National Institute of Neuroscience (INN), 10125 Turin, Italy
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da S. Hage-Melim LI, Ferreira JV, de Oliveira NK, Correia LC, Almeida MR, Poiani JG, Taft CA, de Paula da Silva CH. The Impact of Natural Compounds on the Treatment of Neurodegenerative Diseases. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666190327100418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases (NDDs) are characterized by a progressive deterioration of the motor and/or cognitive function, that are often accompanied by psychiatric disorders, caused by a selective loss of neurons in the central nervous system. Among the NDDs we can mention Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), spinocerebellar ataxia 3 (SCA3), spinal and bulbar muscular atrophy (SBMA) and Creutzfeldt-Jakob disease (CJD). AD and HD are characterized mainly by massive neuronal loss. PD, ALS, SCA3 and SBMA are agerelated diseases which have characteristic motor symptoms. CJD is an NDD caused by prion proteins. With increasing life expectancy, elderly populations tend to have more health problems, such as chronic diseases related to age and disability. Therefore, the development of therapeutic strategies to treat or prevent multiple pathophysiological conditions in the elderly can improve the expectation and quality of life. The attention of researchers has been focused on bioactive natural compounds that represent important resources in the discovery and development of drug candidates against NDDs. In this review, we discuss the pathogenesis, symptoms, potential targets, treatment and natural compounds effective in the treatment of AD, PD, HD, ALS, SCA3, SBMA and CJD.
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Affiliation(s)
- Lorane I. da S. Hage-Melim
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Brazil
| | - Jaderson V. Ferreira
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Brazil
| | - Nayana K.S. de Oliveira
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Brazil
| | - Lenir C. Correia
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Brazil
| | - Marcos R.S. Almeida
- Laboratorio de Quimica Farmaceutica e Medicinal (PharMedChem), Universidade Federal do Amapa, Macapa, Brazil
| | - João G.C. Poiani
- Laboratorio Computacional de Química Farmaceutica, Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Carlton A. Taft
- Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos H.T. de Paula da Silva
- Laboratorio Computacional de Química Farmaceutica, Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
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7
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Cicardi ME, Cristofani R, Crippa V, Ferrari V, Tedesco B, Casarotto E, Chierichetti M, Galbiati M, Piccolella M, Messi E, Carra S, Pennuto M, Rusmini P, Poletti A. Autophagic and Proteasomal Mediated Removal of Mutant Androgen Receptor in Muscle Models of Spinal and Bulbar Muscular Atrophy. Front Endocrinol (Lausanne) 2019; 10:569. [PMID: 31481932 PMCID: PMC6710630 DOI: 10.3389/fendo.2019.00569] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/05/2019] [Indexed: 12/25/2022] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease (MND) caused by a mutant androgen receptor (AR) containing an elongated polyglutamine (polyQ) tract. ARpolyQ toxicity is triggered by androgenic AR ligands, which induce aberrant conformations (misfolding) of the ARpolyQ protein that aggregates. Misfolded proteins perturb the protein quality control (PQC) system leading to cell dysfunction and death. Spinal cord motoneurons, dorsal root ganglia neurons and skeletal muscle cells are affected by ARpolyQ toxicity. Here, we found that, in stabilized skeletal myoblasts (s-myoblasts), ARpolyQ formed testosterone-inducible aggregates resistant to NP-40 solubilization; these aggregates did not affect s-myoblasts survival or viability. Both wild type AR and ARpolyQ were processed via proteasome, but ARpolyQ triggered (and it was also cleared via) autophagy. ARpolyQ reduced two pro-autophagic proteins expression (BAG3 and VCP), leading to decreased autophagic response in ARpolyQ s-myoblasts. Overexpression of two components of the chaperone assisted selective autophagy (CASA) complex (BAG3 and HSPB8), enhanced ARpolyQ clearance, while the treatment with the mTOR independent autophagy activator trehalose induced complete ARpolyQ degradation. Thus, trehalose has beneficial effects in SBMA skeletal muscle models even when autophagy is impaired, possibly by stimulating CASA to assist the removal of ARpolyQ misfolded species/aggregates.
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Affiliation(s)
- Maria Elena Cicardi
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Riccardo Cristofani
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Valeria Crippa
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Veronica Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Barbara Tedesco
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Elena Casarotto
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Marta Chierichetti
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Mariarita Galbiati
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Margherita Piccolella
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Elio Messi
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Serena Carra
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Centro Interdipartimentale di Neuroscienze e Neurotecnologie (CfNN), Università degli Studi di Modena e Reggio Emilia, Modena, Italy
| | - Maria Pennuto
- Department of Neurosciences, Neuromuscular Center, University of Padova, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Dulbecco Telethon Institute, Centre for Integrative Biology (CIBIO), University of Trento, Povo, Italy
| | - Paola Rusmini
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
| | - Angelo Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Dipartimento di Eccellenza 2018-2022, Centro di Eccellenza sulle Malattie Neurodegenerative, Università degli Studi di Milano, Milan, Italy
- Centro InterUniversitario sulle Malattie Neurodegenerative, Università degli Studi di Firenze, Milan, Italy
- *Correspondence: Angelo Poletti
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8
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Senataxin mutations elicit motor neuron degeneration phenotypes and yield TDP-43 mislocalization in ALS4 mice and human patients. Acta Neuropathol 2018; 136:425-443. [PMID: 29725819 DOI: 10.1007/s00401-018-1852-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis type 4 (ALS4) is a rare, early-onset, autosomal dominant form of ALS, characterized by slow disease progression and sparing of respiratory musculature. Dominant, gain-of-function mutations in the senataxin gene (SETX) cause ALS4, but the mechanistic basis for motor neuron toxicity is unknown. SETX is a RNA-binding protein with a highly conserved helicase domain, but does not possess a low-complexity domain, making it unique among ALS-linked disease proteins. We derived ALS4 mouse models by expressing two different senataxin gene mutations (R2136H and L389S) via transgenesis and knock-in gene targeting. Both approaches yielded SETX mutant mice that develop neuromuscular phenotypes and motor neuron degeneration. Neuropathological characterization of SETX mice revealed nuclear clearing of TDP-43, accompanied by TDP-43 cytosolic mislocalization, consistent with the hallmark pathology observed in human ALS patients. Postmortem material from ALS4 patients exhibited TDP-43 mislocalization in spinal cord motor neurons, and motor neurons from SETX ALS4 mice displayed enhanced stress granule formation. Immunostaining analysis for nucleocytoplasmic transport proteins Ran and RanGAP1 uncovered nuclear membrane abnormalities in the motor neurons of SETX ALS4 mice, and nuclear import was delayed in SETX ALS4 cortical neurons, indicative of impaired nucleocytoplasmic trafficking. SETX ALS4 mice thus recapitulated ALS disease phenotypes in association with TDP-43 mislocalization and provided insight into the basis for TDP-43 histopathology, linking SETX dysfunction to common pathways of ALS motor neuron degeneration.
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9
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Dickey AS, Sanchez DN, Arreola M, Sampat KR, Fan W, Arbez N, Akimov S, Van Kanegan MJ, Ohnishi K, Gilmore-Hall SK, Flores AL, Nguyen JM, Lomas N, Hsu CL, Lo DC, Ross CA, Masliah E, Evans RM, La Spada AR. PPARδ activation by bexarotene promotes neuroprotection by restoring bioenergetic and quality control homeostasis. Sci Transl Med 2018; 9:9/419/eaal2332. [PMID: 29212711 DOI: 10.1126/scitranslmed.aal2332] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 08/09/2017] [Indexed: 01/02/2023]
Abstract
Neurons must maintain protein and mitochondrial quality control for optimal function, an energetically expensive process. The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that promote mitochondrial biogenesis and oxidative metabolism. We recently determined that transcriptional dysregulation of PPARδ contributes to Huntington's disease (HD), a progressive neurodegenerative disorder resulting from a CAG-polyglutamine repeat expansion in the huntingtin gene. We documented that the PPARδ agonist KD3010 is an effective therapy for HD in a mouse model. PPARδ forms a heterodimer with the retinoid X receptor (RXR), and RXR agonists are capable of promoting PPARδ activation. One compound with potent RXR agonist activity is the U.S. Food and Drug Administration-approved drug bexarotene. We tested the therapeutic potential of bexarotene in HD and found that bexarotene was neuroprotective in cellular models of HD, including medium spiny-like neurons generated from induced pluripotent stem cells (iPSCs) derived from patients with HD. To evaluate bexarotene as a treatment for HD, we treated the N171-82Q mouse model with the drug and found that bexarotene improved motor function, reduced neurodegeneration, and increased survival. To determine the basis for PPARδ neuroprotection, we evaluated metabolic function and noted markedly impaired oxidative metabolism in HD neurons, which was rescued by bexarotene or KD3010. We examined mitochondrial and protein quality control in cellular models of HD and observed that treatment with a PPARδ agonist promoted cellular quality control. By boosting cellular activities that are dysfunctional in HD, PPARδ activation may have therapeutic applications in HD and potentially other neurodegenerative diseases.
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Affiliation(s)
- Audrey S Dickey
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dafne N Sanchez
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Martin Arreola
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kunal R Sampat
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Weiwei Fan
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA 92037, USA
| | - Nicolas Arbez
- Departments of Psychiatry, Neurology, and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Sergey Akimov
- Departments of Psychiatry, Neurology, and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Michael J Van Kanegan
- Center for Drug Discovery and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kohta Ohnishi
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - April L Flores
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Janice M Nguyen
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nicole Lomas
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cynthia L Hsu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Donald C Lo
- Center for Drug Discovery and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Christopher A Ross
- Departments of Psychiatry, Neurology, and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Eliezer Masliah
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA.,Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, San Diego, CA 92037, USA.,Howard Hughes Medical Institute, Salk Institute for Biological Studies, San Diego, CA 92037, USA
| | - Albert R La Spada
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA. .,Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.,Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA.,Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA 92093, USA
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10
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Pennuto M, Rinaldi C. From gene to therapy in spinal and bulbar muscular atrophy: Are we there yet? Mol Cell Endocrinol 2018; 465:113-121. [PMID: 28688959 DOI: 10.1016/j.mce.2017.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 01/12/2023]
Abstract
Abnormal polyglutamine expansions in the androgen receptor (AR) cause a muscular condition, known as Kennedy's disease or spinal and bulbar muscular atrophy (SBMA). The disease is transmitted in an X-linked fashion and is clinically characterized by weakness, atrophy and fasciculations of the limb and bulbar muscles as a result of a toxic gain-of-function of the mutant protein. Notably, affected males also show signs of androgen insensitivity, such as gynaecomastia and reduced fertility. The characterization of the natural history of the disease, the increasing understanding of the mechanism of pathogenesis and the elucidation of the functions of normal and mutant AR have offered a momentum for developing a rational therapeutic strategy for this disease. In this special issue on androgens and AR functions, we will review the molecular, biochemical, and cellular mechanisms underlying the pathogenesis of SBMA. We will discuss recent advances on therapeutic approaches and opportunities for this yet incurable disease, ranging from androgen deprivation, to gene silencing, to an expanding repertoire of peripheral targets, including muscle. With the advancement of these strategies into the clinic, it can be reasonably anticipated that the landscape of treatment options for SBMA and other neuromuscular conditions will change rapidly in the near future.
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Affiliation(s)
- Maria Pennuto
- Dulbecco Telethon Institute, Centre for Integrative Biology, University of Trento, 38123 Trento, Italy; Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy.
| | - Carlo Rinaldi
- Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3QX Oxford, UK.
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11
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X-Linked Spinal and Bulbar Muscular Atrophy: From Clinical Genetic Features and Molecular Pathology to Mechanisms Underlying Disease Toxicity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:103-133. [PMID: 29427100 DOI: 10.1007/978-3-319-71779-1_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spinal and Bulbar Muscular Atrophy (SBMA) is an inherited neuromuscular disorder caused by a CAG-polyglutamine (polyQ) repeat expansion in the androgen receptor (AR) gene. Unlike other polyQ diseases, where the function of the native causative protein is unknown, the biology of AR is well understood, and this knowledge has informed our understanding of how native AR function interfaces with polyQ-AR dysfunction. Furthermore, ligand-dependent activation of AR has been linked to SBMA disease pathogenesis, and has led to a thorough study of androgen-mediated effects on polyQ-AR stability, degradation, and post-translational modifications, as well as their roles in the disease process. Transcriptional dysregulation, proteostasis dysfunction, and mitochondrial abnormalities are central to polyQ-AR neurotoxicity, most likely via a 'change-of-function' mechanism. Intriguingly, recent work has demonstrated a principal role for skeletal muscle in SBMA disease pathogenesis, indicating that polyQ-AR toxicity initiates in skeletal muscle and results in secondary motor neuron demise. The existence of robust animal models for SBMA has permitted a variety of preclinical trials, driven by recent discoveries of altered cellular processes, and some of this preclinical work has led to human clinical trials. In this chapter, we review SBMA clinical features and disease biology, discuss our current understanding of the cellular and molecular basis of SBMA pathogenesis, and highlight ongoing efforts toward therapy development.
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12
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Sahashi K, Hashizume A, Sobue G, Katsuno M. Progress toward the development of treatment of spinal and bulbar muscular atrophy. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1329088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Kentaro Sahashi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsushi Hashizume
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Gen Sobue
- Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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13
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Modulation of Molecular Chaperones in Huntington’s Disease and Other Polyglutamine Disorders. Mol Neurobiol 2016; 54:5829-5854. [DOI: 10.1007/s12035-016-0120-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 09/12/2016] [Indexed: 12/20/2022]
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14
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Conformational modulation mediated by polyglutamine expansion in CAG repeat expansion disease-associated proteins. Biochem Biophys Res Commun 2016; 478:949-55. [PMID: 27520369 DOI: 10.1016/j.bbrc.2016.08.057] [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: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/26/2022]
Abstract
We have previously reported TR-FRET based immunoassays to detect a conformational change imparted on huntingtin protein by the polyglutamine expansion, which we confirmed using biophysical methodologies. Using these immunoassays, we now report that polyglutamine expansion influences the conformational properties of other polyglutamine disease proteins, exemplified by the androgen receptor (associated with spinal bulbar muscular atrophy) and TATA binding protein (associated with spinocerebellar ataxia 17). Using artificial constructs bearing short or long polyglutamine expansions or a multimerized, unrelated epitope (mimicking the increase in anti-polyglutamine antibody epitopes present in polyglutamine repeats of increasing length) we confirmed that the conformational TR-FRET based immunoassay detects an intrinsic conformational property of polyglutamine repeats. The TR-FRET based conformational immunoassay may represent a rapid, scalable tool to identify modulators of polyglutamine-mediated conformational change in different proteins associated with CAG triplet repeat disorders.
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15
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Chen C, Dienhart JA, Bolton EC. Androgen-Sensitized Apoptosis of HPr-1AR Human Prostate Epithelial Cells. PLoS One 2016; 11:e0156145. [PMID: 27203692 PMCID: PMC4874596 DOI: 10.1371/journal.pone.0156145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/10/2016] [Indexed: 01/27/2023] Open
Abstract
Androgen receptor (AR) signaling is crucial to the development and homeostasis of the prostate gland, and its dysregulation mediates common prostate pathologies. The mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells have been investigated in human and rodent adult prostate. However, the cellular stress response of human prostate epithelial cells is not well understood, though it is central to prostate health and pathology. Here, we report that androgen sensitizes HPr-1AR and RWPE-AR human prostate epithelial cells to cell stress agents and apoptotic cell death. Although 5α-dihydrotestosterone (DHT) treatment alone did not induce cell death, co-treatment of HPr-1AR cells with DHT and an apoptosis inducer, such as staurosporine (STS), TNFt, or hydrogen peroxide, synergistically increased cell death in comparison to treatment with each apoptosis inducer by itself. We found that the synergy between DHT and apoptosis inducer led to activation of the intrinsic/mitochondrial apoptotic pathway, which is supported by robust cleavage activation of caspase-9 and caspase-3. Further, the dramatic depolarization of the mitochondrial membrane potential that we observed upon co-treatment with DHT and STS is consistent with increased mitochondrial outer membrane permeabilization (MOMP) in the pro-apoptotic mechanism. Interestingly, the synergy between DHT and apoptosis inducer was abolished by AR antagonists and inhibitors of transcription and protein synthesis, suggesting that AR mediates pro-apoptotic synergy through transcriptional regulation of MOMP genes. Expression analysis revealed that pro-apoptotic genes (BCL2L11/BIM and AIFM2) were DHT-induced, whereas pro-survival genes (BCL2L1/BCL-XL and MCL1) were DHT-repressed. Hence, we propose that the net effect of these AR-mediated expression changes shifts the balance of BCL2-family proteins, such that androgen signaling sensitizes mitochondria to apoptotic signaling, thus rendering HPr-1AR more vulnerable to cell death signals. Our study offers insight into AR-mediated regulation of prostate epithelial cell death signaling.
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Affiliation(s)
- Congcong Chen
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jason A. Dienhart
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Eric C. Bolton
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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Abstract
Disrupted brain iron homeostasis is a common feature of neurodegenerative disease. To begin to understand how neuronal iron handling might be involved, we focused on dopaminergic neurons and asked how inactivation of transport proteins affected iron homeostasis in vivo in mice. Loss of the cellular iron exporter, ferroportin, had no apparent consequences. However, loss of transferrin receptor 1, involved in iron uptake, caused neuronal iron deficiency, age-progressive degeneration of a subset of dopaminergic neurons, and motor deficits. There was gradual depletion of dopaminergic projections in the striatum followed by death of dopaminergic neurons in the substantia nigra. Damaged mitochondria accumulated, and gene expression signatures indicated attempted axonal regeneration, a metabolic switch to glycolysis, oxidative stress, and the unfolded protein response. We demonstrate that loss of transferrin receptor 1, but not loss of ferroportin, can cause neurodegeneration in a subset of dopaminergic neurons in mice.
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17
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PPAR-δ is repressed in Huntington's disease, is required for normal neuronal function and can be targeted therapeutically. Nat Med 2015; 22:37-45. [PMID: 26642438 PMCID: PMC4752002 DOI: 10.1038/nm.4003] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/04/2015] [Indexed: 02/05/2023]
Abstract
Huntington’s disease (HD) is a progressive neurodegenerative disorder caused by a CAG-polyglutamine repeat expansion in the huntingtin (htt) gene. We found that peroxisome proliferator-activated receptor delta (PPARδ) interacts with htt and that mutant htt represses PPARδ-mediated transactivation. Increased PPARδ transactivation ameliorated mitochondrial dysfunction and improved cell survival of HD neurons. Expression of dominant-negative PPARδ in CNS was sufficient to induce motor dysfunction, neurodegeneration, mitochondrial abnormalities, and transcriptional alterations that recapitulated HD-like phenotypes. Expression of dominant-negative PPARδ specifically in the striatum of medium spiny neurons in mice yielded HD-like motor phenotypes, accompanied by striatal neuron loss. In mouse models of HD, pharmacologic activation of PPAR δ, using the agonist KD3010, improved motor function, reduced neurodegeneration, and increased survival. PPAR δ activation also reduced htt-induced neurotoxicity in vitro and in medium spiny-like neurons generated from human HD stem cells, indicating that PPAR δ activation may be beneficial in individuals with HD and related disorders.
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Finsterer J, Mishra A, Wakil S, Pennuto M, Soraru G. Mitochondrial implications in bulbospinal muscular atrophy (Kennedy disease). Amyotroph Lateral Scler Frontotemporal Degener 2015; 17:112-8. [PMID: 26428534 DOI: 10.3109/21678421.2015.1089910] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
There is increasing evidence that mitochondrial functions are secondarily disturbed in bulbospinal muscular atrophy (BSMA). This review focuses on the relation between BSMA and the effect of the expanded polyglutamine (poly-Q) androgen receptor (AR) on mitochondrial functions. Mitochondrial functions in bulbospinal muscular atrophy (SBMA) are affected on the molecular, clinical, and therapeutic level. On the molecular level there is down-regulation of various nuclear-DNA-encoded mitochondrial proteins by mutant androgen receptor (mAR), colocalization of the mAR with various mitochondrial proteins, association of mAR aggregates with mitochondria resulting in abnormal distribution of mitochondria, mtDNA depletion or multiple mtDNA deletions, mitochondrial membrane depolarization, increase in reactive oxidative species, and activation of the mitochondrial caspase pathway. On the clinical level various mitochondrial disorders mimic SBMA, and on the therapeutic level pioglitazone expresses PPAR-γ, cyclosporine-A restores mitochondrial membrane potentials, coenzyme-Q and idebenone reduce oxidative stress, and geldanamycin up-regulates protective mitochondrial heat shock proteins. In conclusion, in BSMA mitochondrial dysfunction results from various interactions of elongated poly-Q AR with mitochondria, mitochondrial proteins, nuclear or mitochondrial DNA, causing oxidative stress, decreased mitochondrial membrane potential, or activation of the mitochondrial caspase pathway. Additionally, mitochondrial disease may mimic BSMA and therapeutic approaches may depend on modifications of mitochondrial pathways.
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Affiliation(s)
| | | | - Salma Wakil
- c Department of Genetics , King Faisal Specialist Hospital and Research Centre , Riyadh , Saudi Arabia
| | - Maria Pennuto
- d Dulbecco Telethon Institute Laboratory of Neurodegenerative Diseases, Centre for Integrative Biology (CIBIO) , University of Trento , Trento
| | - Gianni Soraru
- e Department of Neurosciences , University of Padova , Italy
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19
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Trinucleotide repeats and protein folding and disease: the perspective from studies with the androgen receptor. Future Sci OA 2015; 1:FSO47. [PMID: 28031874 PMCID: PMC5137883 DOI: 10.4155/fso.15.47] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The androgen receptor (AR), a ligand activated transcription factor plays a number of roles in reproduction, homeostasis and pathogenesis of disease. It has two major polymorphic sequences; a polyglutamine and a polyglycine repeat that determine the length of the protein and influence receptor folding, structure and function. Here, we review the role the folding of the AR plays in the pathogenesis of spinal-bulbar muscular atrophy (SBMA), a neuromuscular degenerative disease arising from expansion of the polyglutamine repeat. We discuss current management for SBMA patients and how research on AR structure function may lead to future drug treatments.
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20
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Pennuto M, Greensmith L, Pradat PF, Sorarù G. 210th ENMC International Workshop: Research and clinical management of patients with spinal and bulbar muscular atrophy, 27-29 March, 2015, Naarden, The Netherlands. Neuromuscul Disord 2015. [PMID: 26206601 DOI: 10.1016/j.nmd.2015.06.462] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Maria Pennuto
- Dulbecco Telethon Institute Lab of Neurodegenerative Diseases, Centre for Integrative Biology, University of Trento, Italy.
| | - Linda Greensmith
- The Graham Watts Laboratories for Research into Motor Neuron Disease, UCL Institute of Neurology, London, UK
| | - Pierre-François Pradat
- Département des Maladies du Système Nerveux, AP-HP, Groupe hospitalier Pitié-Salpêtrière, F-75013 Paris, France; UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale (LIB), Sorbonne Universités, 75013 Paris, France
| | - Gianni Sorarù
- Department of Neurosciences, University of Padova, Padova, Italy.
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Wang C, Chen W, Miao D, Yu JT, Tan L. Mitochondrial dysfunction in Kennedy's disease: a new pharmacological target? ANNALS OF TRANSLATIONAL MEDICINE 2015; 3:66. [PMID: 25992365 DOI: 10.3978/j.issn.2305-5839.2015.01.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 01/15/2015] [Indexed: 11/14/2022]
Abstract
BACKGROUND Mitochondrial impairment and elevated oxidative stress have been implicated in the pathogenesis of Kennedy's disease. However, there is still no study describing the mitochondrial nutrient management in patients with Kennedy's disease. METHODS We assessed the clinical and electrophysiological features in a patient with Kennedy's disease. This patient was diagnosed by genetic analysis. We also measured the plasma 8-hydroxydeoxyguanosine (8-OHdG) levels of the patient and his family members using commercial enzyme-linked immunosorbent assay (ELISA). Treatment with intravenous L-carnitine (2 g/day) for the patient was started on admission, followed by two weeks. RESULTS Routine laboratory tests revealed a severe elevation of creatine kinase (CK) (606.5 U/L; normal value: 15-170 U/L). Sequencing of the first exon of androgen receptor (AR) revealed an increased number of CAG repeat (50; the normal range from 10-36) in the patient. Plasma 8-OHdG level in the patient was relatively elevated (34.68±1.01 ng/mL) compared with the female carriers and non-carriers. Two weeks after L-carnitine treatment, we observed a reduction of approximately 40% in CK level (391 U/L) in the patient. CONCLUSIONS Oxidative stress resulting from mitochondrial dysfunction could be involved in Kennedy's disease. Targeting the mitochondrial dysfunction in Kennedy's disease may have significant therapeutic potential.
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Affiliation(s)
- Chong Wang
- 1 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China ; 2 Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Wei Chen
- 1 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China ; 2 Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Dan Miao
- 1 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China ; 2 Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Jin-Tai Yu
- 1 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China ; 2 Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Lan Tan
- 1 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China ; 2 Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
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22
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Guyenet SJ, Mookerjee SS, Lin A, Custer SK, Chen SF, Sopher BL, La Spada AR, Ellerby LM. Proteolytic cleavage of ataxin-7 promotes SCA7 retinal degeneration and neurological dysfunction. Hum Mol Genet 2015; 24:3908-17. [PMID: 25859008 DOI: 10.1093/hmg/ddv121] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 04/07/2015] [Indexed: 11/12/2022] Open
Abstract
The neurodegenerative disorder spinocerebellar ataxia type 7 (SCA7) is caused by a polyglutamine (polyQ) expansion in the ataxin-7 protein, categorizing SCA7 as one member of a large class of heritable neurodegenerative proteinopathies. Cleavage of ataxin-7 by the protease caspase-7 has been demonstrated in vitro, and the accumulation of proteolytic cleavage products in SCA7 patients and mouse models has been identified as an early pathological change. However, it remains unknown whether a causal relationship exists between ataxin-7 proteolysis and in vivo SCA7 disease progression. To determine whether caspase cleavage is a critical event in SCA7 disease pathogenesis, we generated transgenic mice expressing polyQ-expanded ataxin-7 with a second-site mutation (D266N) to prevent caspase-7 proteolysis. When we compared SCA7-D266N mice with SCA7 mice lacking the D266N mutation, we found that SCA7-D266N mice exhibited improved motor performance, reduced neurodegeneration and substantial lifespan extension. Our findings indicate that proteolysis at the D266 caspase-7 cleavage site is an important mediator of ataxin-7 neurotoxicity, suggesting that inhibition of caspase-7 cleavage of polyQ-ataxin-7 may be a promising therapeutic strategy for this untreatable disorder.
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Affiliation(s)
| | | | - Amy Lin
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Sylvia F Chen
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Bryce L Sopher
- Department of Neurology, University of Washington, Seattle, WA, USA
| | - Albert R La Spada
- Department of Medicine (Medical Genetics) and Department of Cellular and Molecular Medicine, Division of Biological Sciences, Institute for Genomic Medicine, and the Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, USA, Department of Neurosciences, Division of Biological Sciences, Institute for Genomic Medicine, and the Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, USA, Department of Pediatrics, Division of Biological Sciences, Institute for Genomic Medicine, and the Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA, USA and Rady Children's Hospital, San Diego, CA 92123, USA
| | - Lisa M Ellerby
- The Buck Institute for Research on Aging, Novato, CA 94945, USA,
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The role of the immune system in triplet repeat expansion diseases. Mediators Inflamm 2015; 2015:873860. [PMID: 25873774 PMCID: PMC4385693 DOI: 10.1155/2015/873860] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 11/17/2022] Open
Abstract
Trinucleotide repeat expansion disorders (TREDs) are a group of dominantly inherited neurological diseases caused by the expansion of unstable repeats in specific regions of the associated genes. Expansion of CAG repeat tracts in translated regions of the respective genes results in polyglutamine- (polyQ-) rich proteins that form intracellular aggregates that affect numerous cellular activities. Recent evidence suggests the involvement of an RNA toxicity component in polyQ expansion disorders, thus increasing the complexity of the pathogenic processes. Neurodegeneration, accompanied by reactive gliosis and astrocytosis is the common feature of most TREDs, which may suggest involvement of inflammation in pathogenesis. Indeed, a number of immune response markers have been observed in the blood and CNS of patients and mouse models, and the activation of these markers was even observed in the premanifest stage of the disease. Although inflammation is not an initiating factor of TREDs, growing evidence indicates that inflammatory responses involving astrocytes, microglia, and the peripheral immune system may contribute to disease progression. Herein, we review the involvement of the immune system in the pathogenesis of triplet repeat expansion diseases, with particular emphasis on polyglutamine disorders. We also present various therapeutic approaches targeting the dysregulated inflammation pathways in these diseases.
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24
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Heine EM, Berger TR, Pluciennik A, Orr CR, Zboray L, Merry DE. Proteasome-mediated proteolysis of the polyglutamine-expanded androgen receptor is a late event in spinal and bulbar muscular atrophy (SBMA) pathogenesis. J Biol Chem 2015; 290:12572-84. [PMID: 25795778 DOI: 10.1074/jbc.m114.617894] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Indexed: 01/08/2023] Open
Abstract
Proteolysis of polyglutamine-expanded proteins is thought to be a required step in the pathogenesis of several neurodegenerative diseases. The accepted view for many polyglutamine proteins is that proteolysis of the mutant protein produces a "toxic fragment" that induces neuronal dysfunction and death in a soluble form; toxicity of the fragment is buffered by its incorporation into amyloid-like inclusions. In contrast to this view, we show that, in the polyglutamine disease spinal and bulbar muscular atrophy, proteolysis of the mutant androgen receptor (AR) is a late event. Immunocytochemical and biochemical analyses revealed that the mutant AR aggregates as a full-length protein, becoming proteolyzed to a smaller fragment through a process requiring the proteasome after it is incorporated into intranuclear inclusions. Moreover, the toxicity-predicting conformational antibody 3B5H10 bound to soluble full-length AR species but not to fragment-containing nuclear inclusions. These data suggest that the AR is toxic as a full-length protein, challenging the notion of polyglutamine protein fragment-associated toxicity by redefining the role of AR proteolysis in spinal and bulbar muscular atrophy pathogenesis.
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Affiliation(s)
- Erin M Heine
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Tamar R Berger
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Anna Pluciennik
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Christopher R Orr
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Lori Zboray
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Diane E Merry
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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25
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Cortes CJ, Miranda HC, Frankowski H, Batlevi Y, Young JE, Le A, Ivanov N, Sopher BL, Carromeu C, Muotri AR, Garden GA, La Spada AR. Polyglutamine-expanded androgen receptor interferes with TFEB to elicit autophagy defects in SBMA. Nat Neurosci 2014; 17:1180-9. [PMID: 25108912 PMCID: PMC4180729 DOI: 10.1038/nn.3787] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 07/16/2014] [Indexed: 12/19/2022]
Abstract
Macroautophagy (hereafter autophagy) is a key pathway in neurodegeneration. Despite protective actions, autophagy may contribute to neuron demise when dysregulated. Here we consider X-linked spinal and bulbar muscular atrophy (SBMA), a repeat disorder caused by polyglutamine-expanded androgen receptor (polyQ-AR). We found that polyQ-AR reduced long-term protein turnover and impaired autophagic flux in motor neuron-like cells. Ultrastructural analysis of SBMA mice revealed a block in autophagy pathway progression. We examined the transcriptional regulation of autophagy and observed a functionally significant physical interaction between transcription factor EB (TFEB) and AR. Normal AR promoted, but polyQ-AR interfered with, TFEB transactivation. To evaluate physiological relevance, we reprogrammed patient fibroblasts to induced pluripotent stem cells and then to neuronal precursor cells (NPCs). We compared multiple SBMA NPC lines and documented the metabolic and autophagic flux defects that could be rescued by TFEB. Our results indicate that polyQ-AR diminishes TFEB function to impair autophagy and promote SBMA pathogenesis.
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Affiliation(s)
- Constanza J Cortes
- 1] Department of Pediatrics, University of California, San Diego, La Jolla, California, USA. [2]
| | - Helen C Miranda
- 1] Department of Pediatrics, University of California, San Diego, La Jolla, California, USA. [2] Department of Cellular &Molecular Medicine, University of California, San Diego, La Jolla, California, USA. [3]
| | - Harald Frankowski
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Yakup Batlevi
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Jessica E Young
- Department of Cellular &Molecular Medicine, University of California, San Diego, La Jolla, California, USA
| | - Amy Le
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Nishi Ivanov
- 1] Center on Human Development &Disability, University of Washington, Seattle, Washington, USA. [2] Department of Neurology, University of Washington, Seattle, Washington, USA
| | - Bryce L Sopher
- Department of Neurology, University of Washington, Seattle, Washington, USA
| | - Cassiano Carromeu
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Alysson R Muotri
- 1] Department of Pediatrics, University of California, San Diego, La Jolla, California, USA. [2] Department of Cellular &Molecular Medicine, University of California, San Diego, La Jolla, California, USA. [3] Department of Neurosciences, University of California, San Diego, La Jolla, California, USA. [4] Institute for Genomic Medicine, University of California, San Diego, La Jolla, California, USA. [5] Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California, USA. [6] Rady Children's Hospital, San Diego, California, USA
| | - Gwenn A Garden
- 1] Center on Human Development &Disability, University of Washington, Seattle, Washington, USA. [2] Department of Neurology, University of Washington, Seattle, Washington, USA
| | - Albert R La Spada
- 1] Department of Pediatrics, University of California, San Diego, La Jolla, California, USA. [2] Department of Cellular &Molecular Medicine, University of California, San Diego, La Jolla, California, USA. [3] Department of Neurosciences, University of California, San Diego, La Jolla, California, USA. [4] Institute for Genomic Medicine, University of California, San Diego, La Jolla, California, USA. [5] Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California, USA. [6] Rady Children's Hospital, San Diego, California, USA. [7] Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
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26
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Pei N, Jie F, Luo J, Wan R, Zhang Y, Chen X, Liang Z, Du H, Li A, Chen B, Zhang Y, Sumners C, Li J, Gu W, Li H. Gene expression profiling associated with angiotensin II type 2 receptor-induced apoptosis in human prostate cancer cells. PLoS One 2014; 9:e92253. [PMID: 24658029 PMCID: PMC3962398 DOI: 10.1371/journal.pone.0092253] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 02/19/2014] [Indexed: 11/30/2022] Open
Abstract
Increased expression of angiotensin II type 2 receptor (AT2R) induces apoptosis in numerous tumor cell lines, with either Angiotensin II-dependent or Angiotensin II-independent regulation, but its molecular mechanism remains poorly understood. Here, we used PCR Array analysis to determine the gene and microRNA expression profiles in human prostate cancer cell lines transduced with AT2R recombinant adenovirus. Our results demonstrated that AT2R over expression leads to up-regulation of 6 apoptosis-related genes (TRAIL-R2, BAG3, BNIPI, HRK, Gadd45a, TP53BP2), 2 cytokine genes (IL6 and IL8) and 1 microRNA, and down-regulation of 1 apoptosis-related gene TNFSF10 and 2 cytokine genes (BMP6, BMP7) in transduced DU145 cells. HRK was identified as an up-regulated gene in AT2R-transduced PC-3 cells by real-time RT-PCR. Next, we utilized siRNAs to silence the up-regulated genes to further determine their roles on AT2R overexpression mediated apoptosis. The results showed downregulation of Gadd45a reduced the apoptotic effect by ∼30% in DU145 cells, downregulation of HRK reduced AT2R-mediated apoptosis by more than 50% in PC-3 cells, while downregulation of TRAIL-R2 enhanced AT2R-mediated apoptosis more than 4 times in DU145 cells. We also found that the effects on AT2R-mediated apoptosis caused by downregulation of Gadd45a, TRAIL-R2 and HRK were independent in activation of p38 MAPK, p44/42 MAPK and p53. Taken together, our results demonstrated that TRAIL-R2, Gadd45a and HRK may be novel target genes for further study of the mechanism of AT2R-mediated apoptosis in prostate cancer cells.
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Affiliation(s)
- Nana Pei
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Feilong Jie
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Jie Luo
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Renqiang Wan
- Department of Otolaryngology-Head and Neck Surgery, Guangdong No. 2 Provincial People’s Hospital, Guangzhou, Guangdong, China
| | - Yanling Zhang
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Xinglu Chen
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhibing Liang
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongyan Du
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Andrew Li
- Department of Neuroscience, University of Florida, Gainesville, Florida, United States of America
| | - Baihong Chen
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Yi Zhang
- Department of Pharmacology, University of Florida, Gainesville, Florida, United States of America
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, United States of America
| | - Jinlong Li
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
- * E-mail: (JL); (WG); (HL)
| | - Weiwang Gu
- Institute of Comparative Medicine and Center of Laboratory Animals, Southern Medical University, Guangzhou, Guangdong, China
- * E-mail: (JL); (WG); (HL)
| | - Hongwei Li
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
- * E-mail: (JL); (WG); (HL)
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27
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Chua JP, Lieberman AP. Pathogenic mechanisms and therapeutic strategies in spinobulbar muscular atrophy. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2013; 12:1146-1156. [PMID: 24040817 PMCID: PMC4003563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/10/2012] [Accepted: 07/10/2012] [Indexed: 06/02/2023]
Abstract
We review the genetic and clinical features of spinobulbar muscular atrophy (SBMA), a progressive neuromuscular disorder caused by a CAG/glutamine tract expansion in the androgen receptor. SBMA was the first polyglutamine disease to be discovered, and we compare and contrast it with related degenerative disorders of the nervous system caused by expanded glutamine tracts. We review the cellular and animals models that have been most widely used to study this disorder, and highlight insights into disease pathogenesis derived from this work. These model systems have revealed critical aspects of the disease, including its hormone dependence, a feature that underlies disease occurrence only in men with the mutant allele. We discuss how this and other findings have been translated to clinical trials for SBMA patients, and examine emerging therapeutic targets that have been identified by recent work.
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Affiliation(s)
| | - Andrew P Lieberman
- Department of Pathology, University of Michigan Medical School, 3510 MSRB1, 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109-0605, USA.
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28
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Savulescu D, Feng J, Ping YS, Mai O, Boehm U, He B, O'Malley BW, Melamed P. Gonadotropin-releasing hormone-regulated prohibitin mediates apoptosis of the gonadotrope cells. Mol Endocrinol 2013; 27:1856-70. [PMID: 24085822 DOI: 10.1210/me.2013-1210] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
GnRH regulates circulating levels of the gonadotropins but has also been implicated in establishing the gonadotrope cell population. Consistent with this, GnRH induces proliferation of partially differentiated gonadotropes, while reducing the numbers of fully differentiated cells. We have previously reported that the proapoptotic protein, prohibitin (PHB) is expressed more abundantly in gonadotrope-derived LβT2 cells than in partially differentiated αT3-1 gonadotrope precursor cells, suggesting a possible role for PHB in GnRH-induced apoptosis. We show here that PHB is required for GnRH-induced apoptosis in mature gonadotropes. PHB expression and activity are regulated by GnRH: its transcription is via c-Jun NH2-terminal kinase, whereas its nuclear export follows activation of ERK. Moreover, PHB levels are down-regulated by microRNA27, which is expressed at lower levels in mature gonadotropes, possibly explaining the switch to an apoptotic response with development. PHB is required for mitochondrial import of the proapoptotic BAX, whose expression is also induced by GnRH-activated c-Jun NH2-terminal kinase, as is expression of the BH3-only protein, HRK, and this too plays a role in GnRH-induced apoptosis. Finally, we show that gonadotrope-specific PHB-knockout mice display reproductive abnormalities, including a larger gonadotrope population, increased LH levels, reduced fertility, and altered gonad development. We thus demonstrate a role for PHB in GnRH-induced cell death in mature gonadotropes, which is crucial for the normal development and function of the reproductive axis.
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Affiliation(s)
- Dana Savulescu
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000 Israel.
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29
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Wen S, Shang Z, Zhu S, Chang C, Niu Y. Androgen receptor enhances entosis, a non-apoptotic cell death, through modulation of Rho/ROCK pathway in prostate cancer cells. Prostate 2013; 73:1306-15. [PMID: 23775364 DOI: 10.1002/pros.22676] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 03/25/2013] [Indexed: 12/27/2022]
Abstract
BACKGROUND Cell-in-cell phenomenon has been found for more than a century. Entosis, which is a newly found homogeneous cell-in-cell phenomenon and a non-apoptosis cell death progress, has unclear function in prostate cancer progression. Here, we dissected mechanism of AR signaling related to entosis incidence in PCa progression. METHODS Two stable PCa cell lines, named LNCaP-ARsi and C4-2-ARsi were established with stably transfected AR-shRNA to knockdown AR mRNA expression in LNCaP and C4-2 cells, respectively. PC3-AR9 cell line was also established after stably transfecting full-length AR-cDNA into PC3 cells. All these cells were cultured in poly-HEME-coated plates to induce entosis, which is demonstrated via double staining. RESULTS Androgen-DHT could enhance entosis in LNCaP, C4-2 and PC3-AR9 PCa cells in a dose dependent manner. Knock-down of AR in LNCaP and C4-2 significantly suppressed entosis as compared to LNCaP-ARsc and C4-2-ARsc cells at both 1 and 10 nM DHT condition (P < 0.05). And suppression of Rho/ROCK expression resulted in interruption of AR-mediated entosis. Human PCa samples surveys demonstrated that entosis was found only in CRPC but not in BPH and ADPC where AR was less expressed as compared to CRPC. CONCLUSIONS These results indicated that AR might play a negative role during PCa progression via influencing entosis by modulating Rho/ROCK pathway. This newly identified AR role of enhancing entosis might help us to better understand the multiple and opposite roles of AR, which could either promote or suppress PCa cell progression via different mechanisms.
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Affiliation(s)
- Simeng Wen
- Chawnshang Chang Sex Hormone Research Center, Tianjin Institute of Urology, Tianjin Medical University, Tianjin, China
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30
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Androgen receptor (AR) positive vs negative roles in prostate cancer cell deaths including apoptosis, anoikis, entosis, necrosis and autophagic cell death. Cancer Treat Rev 2013; 40:31-40. [PMID: 23993415 DOI: 10.1016/j.ctrv.2013.07.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/20/2013] [Accepted: 07/29/2013] [Indexed: 12/21/2022]
Abstract
Androgen/androgen receptor (AR) signaling plays pivotal roles in the prostate development and homeostasis as well as in the progression of prostate cancer (PCa). Androgen deprivation therapy (ADT) with anti-androgens remains as the main treatment for later stage PCa, and it has been shown to effectively suppress PCa growth during the first 12-24 months. However, ADT eventually fails and tumors may re-grow and progress into the castration resistant stage. Recent reports revealed that AR might play complicated and even opposite roles in PCa progression that might depend on cell types and tumor stages. Importantly, AR may influence PCa progression via differential modulation of various cell deaths including apoptosis, anoikis, entosis, necrosis, and autophagic cell deaths. Targeting AR may induce PCa cell apoptosis, autophagic cell deaths and programmed necrosis, yet targeting AR may suppress cell deaths via anoikis and entosis that may potentially lead to increased metastasis. These differential functions of AR in various types of PCa cell death might challenge the current ADT with anti-androgens treatment. Further detailed dissection of molecular mechanisms by which AR modulates different PCa cell deaths will help us to develop a better therapy to battle PCa.
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31
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Rusmini P, Crippa V, Giorgetti E, Boncoraglio A, Cristofani R, Carra S, Poletti A. Clearance of the mutant androgen receptor in motoneuronal models of spinal and bulbar muscular atrophy. Neurobiol Aging 2013; 34:2585-603. [PMID: 23810450 PMCID: PMC3748343 DOI: 10.1016/j.neurobiolaging.2013.05.026] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 04/23/2013] [Accepted: 05/27/2013] [Indexed: 12/13/2022]
Abstract
Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease caused by an abnormal expansion of a tandem CAG repeat in exon 1 of the androgen receptor (AR) gene that results in an abnormally long polyglutamine tract (polyQ) in the AR protein. As a result, the mutant AR (ARpolyQ) misfolds, forming cytoplasmic and nuclear aggregates in the affected neurons. Neurotoxicity only appears to be associated with the formation of nuclear aggregates. Thus, improved ARpolyQ cytoplasmic clearance, which indirectly decreases ARpolyQ nuclear accumulation, has beneficial effects on affected motoneurons. In addition, increased ARpolyQ clearance contributes to maintenance of motoneuron proteostasis and viability, preventing the blockage of the proteasome and autophagy pathways that might play a role in the neuropathy in SBMA. The expression of heat shock protein B8 (HspB8), a member of the small heat shock protein family, is highly induced in surviving motoneurons of patients affected by motoneuron diseases, where it seems to participate in the stress response aimed at cell protection. We report here that HspB8 facilitates the autophagic removal of misfolded aggregating species of ARpolyQ. In addition, though HspB8 does not influence p62 and LC3 (two key autophagic molecules) expression, it does prevent p62 bodies formation, and restores the normal autophagic flux in these cells. Interestingly, trehalose, a well-known autophagy stimulator, induces HspB8 expression, suggesting that HspB8 might act as one of the molecular mediators of the proautophagic activity of trehalose. Collectively, these data support the hypothesis that treatments aimed at restoring a normal autophagic flux that result in the more efficient clearance of mutant ARpolyQ might produce beneficial effects in SBMA patients.
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Affiliation(s)
- Paola Rusmini
- Sezione di Biomedicina e Endocrinologia, Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro di Eccellenza sulle Malattie Neurodegenerative, Universita' degli Studi di Milano, Milan, Italy
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32
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Beitel LK, Alvarado C, Mokhtar S, Paliouras M, Trifiro M. Mechanisms mediating spinal and bulbar muscular atrophy: investigations into polyglutamine-expanded androgen receptor function and dysfunction. Front Neurol 2013; 4:53. [PMID: 23720649 PMCID: PMC3654311 DOI: 10.3389/fneur.2013.00053] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 04/26/2013] [Indexed: 11/13/2022] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA, Kennedy’s disease), a late-onset neuromuscular disorder, is caused by expansion of the polymorphic polyglutamine tract in the androgen receptor (AR). The AR is a ligand-activated transcription factor, but plays roles in other cellular pathways. In SBMA, selective motor neuron degeneration occurs in the brainstem and spinal cord, thus the causes of neuronal dysfunction have been studied. However, pathogenic pathways in muscles may also be involved. Cultured cells, fly and mouse models are used to study the molecular mechanisms leading to SBMA. Both the structure of the polyglutamine-expanded AR (polyQ AR) and its interactions with other proteins are altered relative to the normal AR. The ligand-dependent translocation of the polyQ AR to the nucleus appears to be critical, as are interdomain interactions. The polyQ AR, or fragments thereof, can form nuclear inclusions, but their pathogenic or protective nature is unclear. Other data suggests soluble polyQ AR oligomers can be harmful. Post-translational modifications such as phosphorylation, acetylation, and ubiquitination influence AR function and modulate the deleterious effects of the polyQ AR. Transcriptional dysregulation is highly likely to be a factor in SBMA; deregulation of non-genomic AR signaling may also be involved. Studies on polyQ AR-protein degradation suggest inhibition of the ubiquitin proteasome system and changes to autophagic pathways may be relevant. Mitochondrial function and axonal transport may also be affected by the polyQ AR. Androgens, acting through the AR, can be neurotrophic and are important in muscle development; hence both loss of normal AR functions and gain of novel harmful functions by the polyQ AR can contribute to neurodegeneration and muscular atrophy. Thus investigations into polyQ AR function have shown that multiple complex mechanisms lead to the initiation and progression of SBMA.
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Affiliation(s)
- Lenore K Beitel
- Lady Davis Institute for Medical Research, Jewish General Hospital Montreal, QC, Canada ; Department of Medicine, McGill University Montreal, QC, Canada ; Department of Human Genetics, McGill University Montreal, QC, Canada
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33
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JUN regulates early transcriptional responses to axonal injury in retinal ganglion cells. Exp Eye Res 2013; 112:106-17. [PMID: 23648575 DOI: 10.1016/j.exer.2013.04.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 11/23/2022]
Abstract
The AP1 family transcription factor JUN is an important molecule in the neuronal response to injury. In retinal ganglion cells (RGCs), JUN is upregulated soon after axonal injury and disrupting JUN activity delays RGC death. JUN is known to participate in the control of many different injury response pathways in neurons, including pathways controlling cell death and axonal regeneration. The role of JUN in regulating genes involved in cell death, ER stress, and regeneration was tested to determine the overall importance of JUN in regulating RGC response to axonal injury. Genes from each of these pathways were transcriptionally controlled following axonal injury and Jun deficiency altered the expression of many of these genes. The differentially expressed genes included, Atf3, Ddit3, Ecel1, Gadd45α, Gal, Hrk, Pten, Socs3, and Sprr1a. Two of these genes, Hrk and Atf3, were tested for importance in RGC death using null alleles of each gene. Disruption of the prodeath Bcl2 family member Hrk did not affect the rate or amount of RGC death after axonal trauma. Deficiency in the ATF/CREB family transcription factor Atf3 did lessen the amount of RGC death after injury, though it did not provide long term protection to RGCs. Since JUN's dimerization partner determines its transcriptional targets, the expression of several candidate AP1 family members were examined. Multiple AP1 family members were induced by axonal injury and had a different expression profile in Jun deficient retinas compared to wildtype retinas (Fosl1, Fosl2 and Jund). Overall, JUN appears to play a multifaceted role in regulating RGC response to axonal injury.
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34
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Niimi Y, Takahashi M, Sugawara E, Umeda S, Obayashi M, Sato N, Ishiguro T, Higashi M, Eishi Y, Mizusawa H, Ishikawa K. Abnormal RNA structures (RNA foci) containing a penta-nucleotide repeat (UGGAA)nin the Purkinje cell nucleus is associated with spinocerebellar ataxia type 31 pathogenesis. Neuropathology 2013; 33:600-11. [DOI: 10.1111/neup.12032] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Yusuke Niimi
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Makoto Takahashi
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Emiko Sugawara
- Department of Pathology; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Shigeaki Umeda
- Department of Pathology; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Masato Obayashi
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Nozomu Sato
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Taro Ishiguro
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Miwa Higashi
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Yoshinobu Eishi
- Department of Pathology; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
| | - Kinya Ishikawa
- Department of Neurology and Neurological Science; Graduate School; Tokyo Medical and Dental University; Tokyo Japan
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35
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Chang I, Majid S, Saini S, Zaman MS, Yamamura S, Chiyomaru T, Shahryari V, Fukuhara S, Deng G, Dahiya R, Tanaka Y. Hrk mediates 2-methoxyestradiol-induced mitochondrial apoptotic signaling in prostate cancer cells. Mol Cancer Ther 2013; 12:1049-59. [PMID: 23580416 DOI: 10.1158/1535-7163.mct-12-1187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prostate cancer is one of the most prevalent cancers in males and ranks as the second most common cause of cancer-related deaths. 2-methoxyestradiol (2-ME), an endogenous estrogen metabolite, is a promising anticancer agent for various types of cancers. Although 2-ME has been shown to activate c-Jun-NH2-kinase (JNK) and mitochondrial-dependent apoptotic signaling pathways, the underlying mechanisms, including downstream effectors, remain unclear. Here, we report that the human Bcl-2 homology 3 (BH3)-only protein harakiri (Hrk) is a critical effector of 2-ME-induced JNK/mitochondria-dependent apoptosis in prostate cancer cells. Hrk mRNA and protein are preferentially upregulated by 2-ME, and Hrk induction is dependent on the JNK activation of c-Jun. Hrk knockdown prevents 2-ME-mediated apoptosis by attenuating the decrease in mitochondrial membrane potential, subsequent cytochrome c (cyt c) release, and caspase activation. Involvement of the proapoptotic protein Bak in this process suggested the possible interaction between Hrk and Bak. Thus, Hrk activation by 2-ME or its overexpression displaced Bak from the complex with antiapoptotic protein Bcl-xL, whereas deletion of the Hrk BH3 domain abolished its interaction with Bcl-xL, reducing the proapoptotic function of Hrk. Finally, Hrk is also involved in the 2-ME-mediated reduction of X-linked inhibitor of apoptosis through Bak activation in prostate cancer cells. Together, our findings suggest that induction of the BH3-only protein Hrk is a critical step in 2-ME activation of the JNK-induced apoptotic pathway, targeting mitochondria by liberating proapoptotic protein Bak.
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Affiliation(s)
- Inik Chang
- Department of Urology, San Francisco Veterans Affairs Medical Center and University of California San Francisco, San Francisco, CA 94121, USA
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36
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New routes to therapy for spinal and bulbar muscular atrophy. J Mol Neurosci 2013; 50:514-23. [PMID: 23420040 DOI: 10.1007/s12031-013-9978-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy's disease, is a genetically inherited neuromuscular disorder characterized by loss of lower motor neurons in the brainstem and spinal cord and skeletal muscle fasciculation, weakness, and atrophy. SBMA is caused by expansion of a polyglutamine (polyQ) tract in the gene coding for the androgen receptor (AR). PolyQ expansions cause at least eight other neurological disorders, which are collectively known as polyQ diseases. SBMA is unique in the family of polyQ diseases in that the disease manifests fully in male individuals only. The sex specificity of SBMA is the result of the interaction between mutant AR and its natural ligand, testosterone. Here, we will discuss emerging therapeutic perspectives for SBMA in light of recent findings regarding disease pathogenesis.
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37
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PI3 k/akt inhibition induces apoptosis through p38 activation in neurons. Pharmacol Res 2013; 70:116-25. [PMID: 23376356 DOI: 10.1016/j.phrs.2013.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/15/2013] [Accepted: 01/16/2013] [Indexed: 12/27/2022]
Abstract
Accumulating evidence suggests that the PI3K/AKT pathway is a pro-survival signalling system in neurons. Therefore, the inhibition of this pathway may be implicated in the degeneration of neurons in Parkinson's disease (PD), Alzheimer's disease (AD), and other neurological disorders. Here we study the participation of the mitogen-activated protein kinase (MAPK) pathway on apoptosis induced by PI3K/AKT inhibition in cultured cerebellar granule cells (CGCs). LY294002, a specific PI3K/AKT inhibitor, selectively activated the p38 MAPK kinase pathway and enhanced c-Jun phosphorylation, but did not activate JNK. The pharmacological inhibitors SB203580 (p38 inhibitor) and SP600125 (a JNK inhibitor) protected primary cultures of rat CGCs from LY294002-induced apoptosis. Furthermore, both compounds decreased the phosphorylation of c-Jun and lowered mRNA levels of the pro-apoptotic gene dp5, a direct target of c-Jun. Taken together, our data demonstrate that PI3K/AKT inhibition induces neuronal apoptosis, a process that is mediated by the activation of p38 MAPK/c-Jun/dp5.
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38
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Tsunemi T, Ashe TD, Morrison BE, Soriano KR, Au J, Roque RAV, Lazarowski ER, Damian VA, Masliah E, La Spada AR. PGC-1α rescues Huntington's disease proteotoxicity by preventing oxidative stress and promoting TFEB function. Sci Transl Med 2013; 4:142ra97. [PMID: 22786682 DOI: 10.1126/scitranslmed.3003799] [Citation(s) in RCA: 355] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Huntington's disease (HD) is caused by CAG repeat expansions in the huntingtin (htt) gene, yielding proteins containing polyglutamine repeats that become misfolded and resist degradation. Previous studies demonstrated that mutant htt interferes with transcriptional programs coordinated by the peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC-1α), a regulator of mitochondrial biogenesis and oxidative stress. We tested whether restoration of PGC-1α could ameliorate the symptoms of HD in a mouse model. We found that PGC-1α induction virtually eliminated htt protein aggregation and ameliorated HD neurodegeneration in part by attenuating oxidative stress. PGC-1α promoted htt turnover and the elimination of protein aggregates by activating transcription factor EB (TFEB), a master regulator of the autophagy-lysosome pathway. TFEB alone was capable of reducing htt aggregation and neurotoxicity, placing PGC-1α upstream of TFEB and identifying these two molecules as important therapeutic targets in HD and potentially other neurodegenerative disorders caused by protein misfolding.
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Affiliation(s)
- Taiji Tsunemi
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
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39
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Fischbeck KH. Developing treatment for spinal and bulbar muscular atrophy. Prog Neurobiol 2012; 99:257-61. [PMID: 22668795 PMCID: PMC3460036 DOI: 10.1016/j.pneurobio.2012.05.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/14/2012] [Accepted: 05/15/2012] [Indexed: 12/16/2022]
Abstract
Spinal and bulbar muscular atrophy is unique among the polyglutamine diseases in that the toxicity of the mutant protein, the androgen receptor, is ligand-dependent. In cell culture and animal models the mutant androgen receptor causes protein aggregation and alterations in transcriptional regulation, axonal transport, and mitochondrial function. Various therapeutic approaches have shown efficacy in mouse models, including androgen reduction and agents that alter the processing and degradation of the mutant androgen receptor protein, such as HSP90 inhibitors, IGF-1, and ASC-J9. Clinical trials of androgen-reducing agents have shown indications of efficacy but not proof of clinically meaningful benefit to date. This trial experience has set the stage for future clinical studies of other agents that have been found to be beneficial in transgenic animal models.
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MESH Headings
- Animals
- Clinical Trials as Topic
- Disease Models, Animal
- Humans
- Muscular Atrophy, Spinal/drug therapy
- Muscular Atrophy, Spinal/genetics
- Muscular Atrophy, Spinal/metabolism
- Muscular Atrophy, Spinal/physiopathology
- Muscular Disorders, Atrophic/drug therapy
- Muscular Disorders, Atrophic/genetics
- Muscular Disorders, Atrophic/metabolism
- Peptides/metabolism
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
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Affiliation(s)
- Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35-2A1000, 35 Convent Dr., Bethesda, MD 20892, USA.
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Synergistic silencing by promoter methylation and reduced AP-2α transactivation of the proapoptotic HRK gene confers apoptosis resistance and enhanced tumor growth. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 182:84-95. [PMID: 23159945 DOI: 10.1016/j.ajpath.2012.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/06/2012] [Accepted: 09/18/2012] [Indexed: 02/05/2023]
Abstract
The Harakiri (HRK) gene encodes an important proapoptotic mitochondrial protein of the Bcl-2 family. HRK is expressed in normal tissues but is decreased in many cancers such as melanoma, the mechanisms of which have not been fully elucidated. Here, we demonstrate that HRK is silenced by hypermethylation of a major proximal CpG island in the HRK promoter. Furthermore, we show that HRK is a novel target gene regulated by the transcription factor AP-2α, which interacts with an AP-2α binding site in the HRK promoter. Hypermethylation of the major proximal CpG island (which contains the AP-2α binding site within the most densely methylated -218- to -194-bp region) inhibited AP-2α binding and transcriptional activity. Artificial overexpression of AP-2α in melanoma cells up-regulated HRK transcription, which was further restored by treatment with DNA methyltransferase inhibitor 5-azacytidine. Artificial overexpression of HRK by recombinant adenovirus induced caspase-dependent apoptosis, inhibited melanoma cell growth in vitro, and markedly reduced in vivo melanoma growth in a nude mouse xenograft model. RNA interference by siHRK or siAP-2α reversed the above effects. We conclude that the synergistic effects of HRK promoter hypermethylation and loss of AP-2α transactivation lead to HRK gene silencing and confer resistance to apoptosis and enhanced tumor growth. These novel molecular lesions may provide the basis for new therapeutic approaches to treating AP-2α- and HRK-deficient cancers.
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ATF4 orchestrates a program of BH3-only protein expression in severe hypoxia. Mol Biol Rep 2012; 39:10811-22. [PMID: 23090478 DOI: 10.1007/s11033-012-1975-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 10/01/2012] [Indexed: 01/08/2023]
Abstract
Intratumoral hypoxia is associated with poor prognosis, regardless of the mode of therapy. Cancer cells survive this condition through activating several adaptive signaling pathways, including the integrated stress response (ISR) and autophagy. Activating transcription factor 4 (ATF4) is the major transcriptional mediator of the ISR, which we have shown to be involved in autophagy regulation to protect cells from severe hypoxia. Here we demonstrate that ATF4 orchestrates a program of BH3-only protein expression in severe hypoxia. We find that the BH3-only proteins HRK, PUMA, and NOXA are transcriptionally induced in severe hypoxia and that their expression is abrogated by RNA interference against ATF4. In particular, we show that the BH3-only protein harakiri (HRK) is transactivated by ATF4 in severe hypoxia through direct binding of ATF4 to the promoter region. Furthermore, we demonstrate through siRNA knockdown that HRK induces autophagy and promotes cancer cell survival in severe hypoxia.
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Naratriptan mitigates CGRP1-associated motor neuron degeneration caused by an expanded polyglutamine repeat tract. Nat Med 2012; 18:1531-8. [PMID: 23023499 DOI: 10.1038/nm.2932] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 08/13/2012] [Indexed: 11/08/2022]
Abstract
Spinal and bulbar muscular atrophy (SBMA) is a motor neuron disease caused by the expansion of the CAG triplet repeat within the androgen receptor (AR) gene. Here, we demonstrated that pathogenic AR upregulates the gene encoding calcitonin gene-related peptide α (CGRP1). In neuronal cells, overexpression of CGRP1 induced cellular damage via the activation of the c-Jun N-terminal kinase (JNK) pathway, whereas pharmacological suppression of CGRP1 or JNK attenuated the neurotoxic effects of pathogenic AR. The depletion of CGRP1 inactivated JNK and suppressed neurodegeneration in a mouse model of SBMA. Naratriptan, a serotonin 1B/1D (5-hydroxytryptamine 1B/1D, or 5-HT1B/1D) receptor agonist, decreased CGRP1 expression via the induction of dual-specificity protein phosphatase 1 (DUSP1), attenuated JNK activity and mitigated pathogenic AR-mediated neuronal damage in cellular and mouse SBMA models. These observations suggest that pharmacological activation of the 5-HT1B/1D receptor may be used therapeutically to treat SBMA and other polyglutamine-related neurodegenerative diseases.
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Switonski PM, Szlachcic WJ, Gabka A, Krzyzosiak WJ, Figiel M. Mouse models of polyglutamine diseases in therapeutic approaches: review and data table. Part II. Mol Neurobiol 2012; 46:430-66. [PMID: 22944909 PMCID: PMC3461214 DOI: 10.1007/s12035-012-8316-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Accepted: 07/29/2012] [Indexed: 12/13/2022]
Abstract
Mouse models of human diseases are created both to understand the pathogenesis of the disorders and to find successful therapies for them. This work is the second part in a series of reviews of mouse models of polyglutamine (polyQ) hereditary disorders and focuses on in vivo experimental therapeutic approaches. Like part I of the polyQ mouse model review, this work is supplemented with a table that contains data from experimental studies of therapeutic approaches in polyQ mouse models. The aim of this review was to characterize the benefits and outcomes of various therapeutic strategies in mouse models. We examine whether the therapeutic strategies are specific to a single disease or are applicable to more than one polyQ disorder in mouse models. In addition, we discuss the suitability of mouse models in therapeutic approaches. Although the majority of therapeutic studies were performed in mouse models of Huntington disease, similar strategies were also used in other disease models.
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Affiliation(s)
- Pawel M Switonski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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Mano T, Katsuno M, Banno H, Suzuki K, Suga N, Hashizume A, Tanaka F, Sobue G. Cross-sectional and longitudinal analysis of an oxidative stress biomarker for spinal and bulbar muscular atrophy. Muscle Nerve 2012; 46:692-7. [DOI: 10.1002/mus.23413] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2012] [Indexed: 12/12/2022]
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Katsuno M, Tanaka F, Adachi H, Banno H, Suzuki K, Watanabe H, Sobue G. Pathogenesis and therapy of spinal and bulbar muscular atrophy (SBMA). Prog Neurobiol 2012; 99:246-56. [PMID: 22609045 DOI: 10.1016/j.pneurobio.2012.05.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 04/24/2012] [Accepted: 05/08/2012] [Indexed: 01/18/2023]
Abstract
Spinal and bulbar muscular atrophy (SBMA) is a late-onset motor neuron disease characterized by slowly progressive muscle weakness and atrophy. During the last two decades, basic and clinical research has provided important insights into the disease phenotype and pathophysiology. The cause of SBMA is the expansion of a trinucleotide CAG repeat encoding a polyglutamine tract within the first exon of the androgen receptor (AR) gene. SBMA exclusively affects adult males, whereas females homozygous for the AR mutation do not manifest neurological symptoms. The ligand-dependent nuclear accumulation of the polyglutamine-expanded AR protein is central to the gender-specific pathogenesis of SBMA, although additional steps, e.g., DNA binding, inter-domain interactions, and post-translational modification of AR, modify toxicity. The interactions with co-regulators are another requisite for the toxic properties of the polyglutamine-expanded AR. It is also shown that the polyglutamine-expanded AR induces diverse molecular events, such as transcriptional dysregulation, axonal transport disruption, and mitochondrial dysfunction, which play causative roles in the neurodegeneration in SBMA. The pathogenic AR-induced myopathy also contributes to the non-cell autonomous degeneration of motor neurons. Pre-clinical studies using animal models show that the pathogenic AR-mediated neurodegeneration is suppressed by androgen inactivation, the efficacy of which has been tested in clinical trials. Pharmacological activation of cellular defense machineries, such as molecular chaperones, ubiquitin-proteasome system, and autophagy, also exerts neuroprotective effects in experimental models of SBMA.
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Affiliation(s)
- Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
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Abstract
Polyglutamine neurodegenerative diseases result from the expansion of a trinucleotide CAG repeat, encoding a polyglutamine tract in the disease-causing protein. The process by which each polyglutamine protein exerts its toxicity is complex, involving a variety of mechanisms including transcriptional dysregulation, proteasome impairment and mitochondrial dysfunction. Thus, the most effective and widely applicable therapies are likely to be those designed to eliminate production of the mutant protein upstream of these deleterious effects. RNA-based approaches represent promising therapeutic strategies for polyglutamine diseases, offering the potential to suppress gene expression in a sequence-specific manner at the transcriptional and post-transcriptional levels. In particular, gene silencing therapies capable of discrimination between mutant and wildtype alleles, based on disease-linked polymorphisms or CAG repeat length, might prove crucial in cases where a loss of wild type function is deleterious. Novel methods, such as gene knockdown and replacement, seek to eliminate the technical difficulties associated with allele-specific silencing by avoiding the need to target specific mutations. With a variety of RNA technologies currently being developed to target multiple facets of polyglutamine pathogenesis, the emergence of an effective therapy seems imminent. However, numerous technical obstacles associated with design, discrimination and delivery must be overcome before RNA therapy can be effectively applied in the clinical setting.
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Calpastatin reduces methamphetamine-induced induction in c-Jun phosphorylation, Bax and cell death in neuroblastoma SH-SY5Y cells. Neurosci Lett 2012; 506:7-11. [DOI: 10.1016/j.neulet.2011.10.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 09/22/2011] [Accepted: 10/10/2011] [Indexed: 12/11/2022]
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Parodi S, Pennuto M. Neurotoxic effects of androgens in spinal and bulbar muscular atrophy. Front Neuroendocrinol 2011; 32:416-25. [PMID: 21745497 DOI: 10.1016/j.yfrne.2011.06.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/23/2011] [Accepted: 06/16/2011] [Indexed: 01/13/2023]
Abstract
Expansion of polyglutamine tracts in nine different genes causes selective neuronal degeneration through unknown mechanisms. Expansion of polyglutamine in the androgen receptor is responsible for spinal and bulbar muscular atrophy (SBMA), a neuromuscular disorder characterized by the loss of lower motor neurons in the brainstem and spinal cord. A unique feature of SBMA in the family of polyglutamine diseases is sex specificity. SBMA fully manifests only in males. SBMA is a disease triggered by the binding of polyglutamine androgen receptor to its natural ligand testosterone. Recent evidence has emerged showing that the expanded polyglutamine tract itself is not the only determinant of disease pathogenesis. There is evidence that both the native structure and function of the disease protein strongly influence the pathogenicity of mutant protein. Here, we review recent progress in the understanding of disease pathogenesis and advancements towards development of potential therapeutic strategies for SBMA.
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Affiliation(s)
- Sara Parodi
- Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova 16148, Italy
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Finsterer J. Perspectives of Kennedy's disease. J Neurol Sci 2010; 298:1-10. [PMID: 20846673 DOI: 10.1016/j.jns.2010.08.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 08/15/2010] [Accepted: 08/23/2010] [Indexed: 12/17/2022]
Abstract
Kennedy's disease, also known as bulbospinal muscular atrophy (BSMA), is a rare, adult-onset, X-linked, recessive trinucleotide, polyglutamine (poly-G) disorder, caused by expansion of an unstable CAG-tandem-repeat in exon 1 of the androgen-receptor (AR) gene on chromosome Xq11-12. Poly-Q-expanded AR accumulates in nuclei, undergoes fragmentation and initiates degeneration and loss of motor neurons and dorsal root ganglia. Phenotypically, patients present with weakness and wasting of the facial, bulbar and extremity muscles, sensory disturbances, and endocrinological disturbances, such as gynecomastia and reduced fertility. In the limb muscles weakness and wasting may be symmetric or asymmetric, proximal or distal, or may predominate at the lower or upper limb muscles. There may be mild to severe hyper-CK-emia, elevated testosterone or other sexual hormones, abnormal motor and sensory nerve conduction studies, and neuropathic or rarely myopathic alterations on muscle biopsy. BSMA is diagnosed if the number of CAG-repeats exceeds 40. No causal therapy is available but symptomatic therapy may be beneficial for weakness, tremor, endocrinological abnormalities, muscle cramps, respiratory failure, or dysphagia. The course is slowly progressive and the ability to walk lost only late in life. Only few patients require ventilatory support and life expectancy is only slightly compromised.
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Affiliation(s)
- J Finsterer
- Krankenanstalt Rudolfstiftung, Vienna, Austria.
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Godfrey B, Lin Y, Larson J, Haferkamp B, Xiang J. Proteasomal degradation unleashes the pro-death activity of androgen receptor. Cell Res 2010; 20:1138-47. [PMID: 20479785 DOI: 10.1038/cr.2010.65] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Androgen receptor (AR) is able to promote stress-induced cell death independently of its transcription activity in androgen-independent prostate cancer cells. Yet, the underlying mechanism is incompletely understood. Here, we report that stress-induced proteasomal degradation of AR contributes to its pro-death activity. Upon exposure to ultraviolet light and staurosporine, AR underwent proteasomal degradation. Blockade of AR degradation significantly suppressed stress-induced apoptosis in androgen-independent prostate cancer cells. Ectopic expression of the AR N-terminal (AR-N) domain, which lacks DNA- and ligand-binding abilities, led to cell death without any additional death stimuli. Truncation analysis revealed that AR-N domain contains several sub-domains that regulate the pro-death activity of AR, specifically the first 105 amino acids, which function as a minimal pro-death domain acting upstream of caspases. The pro-apoptotic activity of AR N-terminal fragments was suppressed by ectopic expression of Bcl-2 or selected caspase inhibitors. Thus, our results reveal a novel mechanism by which AR promotes stress-induced cell death in androgen-independent prostate cancer cells.
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Affiliation(s)
- Bradley Godfrey
- Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, IL 60616, USA
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