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Costa RG, Conceição A, Matos CA, Nóbrega C. The polyglutamine protein ATXN2: from its molecular functions to its involvement in disease. Cell Death Dis 2024; 15:415. [PMID: 38877004 PMCID: PMC11178924 DOI: 10.1038/s41419-024-06812-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
A CAG repeat sequence in the ATXN2 gene encodes a polyglutamine (polyQ) tract within the ataxin-2 (ATXN2) protein, showcasing a complex landscape of functions that have been progressively unveiled over recent decades. Despite significant progresses in the field, a comprehensive overview of the mechanisms governed by ATXN2 remains elusive. This multifaceted protein emerges as a key player in RNA metabolism, stress granules dynamics, endocytosis, calcium signaling, and the regulation of the circadian rhythm. The CAG overexpansion within the ATXN2 gene produces a protein with an extended poly(Q) tract, inducing consequential alterations in conformational dynamics which confer a toxic gain and/or partial loss of function. Although overexpanded ATXN2 is predominantly linked to spinocerebellar ataxia type 2 (SCA2), intermediate expansions are also implicated in amyotrophic lateral sclerosis (ALS) and parkinsonism. While the molecular intricacies await full elucidation, SCA2 presents ATXN2-associated pathological features, encompassing autophagy impairment, RNA-mediated toxicity, heightened oxidative stress, and disruption of calcium homeostasis. Presently, SCA2 remains incurable, with patients reliant on symptomatic and supportive treatments. In the pursuit of therapeutic solutions, various studies have explored avenues ranging from pharmacological drugs to advanced therapies, including cell or gene-based approaches. These endeavours aim to address the root causes or counteract distinct pathological features of SCA2. This review is intended to provide an updated compendium of ATXN2 functions, delineate the associated pathological mechanisms, and present current perspectives on the development of innovative therapeutic strategies.
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Affiliation(s)
- Rafael G Costa
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
| | - André Conceição
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
- Champalimaud Research Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Carlos A Matos
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
| | - Clévio Nóbrega
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
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2
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Wang JY, Liu YJ, Zhang XL, Liu YH, Jiang LL, Hu HY. PolyQ-expanded ataxin-2 aggregation impairs cellular processing-body homeostasis via sequestering the RNA helicase DDX6. J Biol Chem 2024; 300:107413. [PMID: 38810698 PMCID: PMC11254730 DOI: 10.1016/j.jbc.2024.107413] [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: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 05/31/2024] Open
Abstract
Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.
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Affiliation(s)
- Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Yin-Hu Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China.
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3
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Liu YJ, Wang JY, Zhang XL, Jiang LL, Hu HY. Ataxin-2 sequesters Raptor into aggregates and impairs cellular mTORC1 signaling. FEBS J 2024; 291:1795-1812. [PMID: 38308810 DOI: 10.1111/febs.17081] [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: 08/02/2023] [Revised: 11/28/2023] [Accepted: 01/26/2024] [Indexed: 02/05/2024]
Abstract
Ataxin-2 (Atx2) is a polyglutamine (polyQ) protein, in which abnormal expansion of the polyQ tract can trigger protein aggregation and consequently cause spinocerebellar ataxia type 2 (SCA2), but the mechanism underlying how Atx2 aggregation leads to proteinopathy remains elusive. Here, we investigate the molecular mechanism and cellular consequences of Atx2 aggregation by molecular cell biology approaches. We have revealed that either normal or polyQ-expanded Atx2 can sequester Raptor, a component of mammalian target of rapamycin complex 1 (mTORC1), into aggregates based on their specific interaction. Further research indicates that the polyQ tract and the N-terminal region (residues 1-784) of Atx2 are responsible for the specific sequestration. Moreover, this sequestration leads to suppression of the mTORC1 activity as represented by down-regulation of phosphorylated P70S6K, which can be reversed by overexpression of Raptor. As mTORC1 is a key regulator of autophagy, Atx2 aggregation and sequestration also induces autophagy by upregulating LC3-II and reducing phosphorylated ULK1 levels. This study proposes that Atx2 sequesters Raptor into aggregates, thereby impairing cellular mTORC1 signaling and inducing autophagy, and will be beneficial for a better understanding of the pathogenesis of SCA2 and other polyQ diseases.
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Affiliation(s)
- Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
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4
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Koppenol R, Conceição A, Afonso IT, Afonso-Reis R, Costa RG, Tomé S, Teixeira D, da Silva JP, Côdesso JM, Brito DVC, Mendonça L, Marcelo A, Pereira de Almeida L, Matos CA, Nóbrega C. The stress granule protein G3BP1 alleviates spinocerebellar ataxia-associated deficits. Brain 2023; 146:2346-2363. [PMID: 36511898 PMCID: PMC10232246 DOI: 10.1093/brain/awac473] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 11/04/2022] [Accepted: 11/25/2022] [Indexed: 09/09/2023] Open
Abstract
Polyglutamine diseases are a group of neurodegenerative disorders caused by an abnormal expansion of CAG repeat tracts in the codifying regions of nine, otherwise unrelated, genes. While the protein products of these genes are suggested to play diverse cellular roles, the pathogenic mutant proteins bearing an expanded polyglutamine sequence share a tendency to self-assemble, aggregate and engage in abnormal molecular interactions. Understanding the shared paths that link polyglutamine protein expansion to the nervous system dysfunction and the degeneration that takes place in these disorders is instrumental to the identification of targets for therapeutic intervention. Among polyglutamine diseases, spinocerebellar ataxias (SCAs) share many common aspects, including the fact that they involve dysfunction of the cerebellum, resulting in ataxia. Our work aimed at exploring a putative new therapeutic target for the two forms of SCA with higher worldwide prevalence, SCA type 2 (SCA2) and type 3 (SCA3), which are caused by expanded forms of ataxin-2 (ATXN2) and ataxin-3 (ATXN3), respectively. The pathophysiology of polyglutamine diseases has been described to involve an inability to properly respond to cell stress. We evaluated the ability of GTPase-activating protein-binding protein 1 (G3BP1), an RNA-binding protein involved in RNA metabolism regulation and stress responses, to counteract SCA2 and SCA3 pathology, using both in vitro and in vivo disease models. Our results indicate that G3BP1 overexpression in cell models leads to a reduction of ATXN2 and ATXN3 aggregation, associated with a decrease in protein expression. This protective effect of G3BP1 against polyglutamine protein aggregation was reinforced by the fact that silencing G3bp1 in the mouse brain increases human expanded ATXN2 and ATXN3 aggregation. Moreover, a decrease of G3BP1 levels was detected in cells derived from patients with SCA2 and SCA3, suggesting that G3BP1 function is compromised in the context of these diseases. In lentiviral mouse models of SCA2 and SCA3, G3BP1 overexpression not only decreased protein aggregation but also contributed to the preservation of neuronal cells. Finally, in an SCA3 transgenic mouse model with a severe ataxic phenotype, G3BP1 lentiviral delivery to the cerebellum led to amelioration of several motor behavioural deficits. Overall, our results indicate that a decrease in G3BP1 levels may be a contributing factor to SCA2 and SCA3 pathophysiology, and that administration of this protein through viral vector-mediated delivery may constitute a putative approach to therapy for these diseases, and possibly other polyglutamine disorders.
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Affiliation(s)
- Rebekah Koppenol
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- PhD Program in Biomedial Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - André Conceição
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- PhD Program in Biomedial Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Inês T Afonso
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Ricardo Afonso-Reis
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Rafael G Costa
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Sandra Tomé
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - Diogo Teixeira
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
| | | | - José Miguel Côdesso
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- PhD Program in Biomedial Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - David V C Brito
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
| | - Liliana Mendonça
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - Adriana Marcelo
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Carlos A Matos
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Clévio Nóbrega
- ABC-RI, Algarve Biomedical Center Research Institute, 8005-139 Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, 8005-139 Faro, Portugal
- Champalimaud Research Program, Champalimaud Center for the Unknown, 1400-038 Lisbon, Portugal
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5
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Yadav M, Bhardwaj A, Yadav A, Dada R, Tanwar M. Molecular genetics of primary open-angle glaucoma. Indian J Ophthalmol 2023; 71:1739-1756. [PMID: 37203025 PMCID: PMC10391438 DOI: 10.4103/ijo.ijo_2570_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Glaucoma is a series of linked optic diseases resulting in progressive vision loss and total blindness due to the acquired loss of retinal ganglion cells. This harm to the optic nerve results in visual impairment and, ultimately, total blindness if left untreated. Primary open-angle glaucoma (POAG) is the most frequent variety within the large family of glaucoma. It is a multifaceted and heterogeneous condition with several environmental and genetic variables aiding in its etiology. By 2040, there will be 111.8 million glaucoma patients globally, with Asia and Africa accounting for the vast majority. The goal of this review is to elaborate on the role of genes (nuclear and mitochondrial) as well as their variants in the pathogenesis of POAG. PubMed and Google Scholar databases were searched online for papers until September 2022. Prevalence and inheritance patterns vary significantly across different ethnic and geographic populations. Numerous causative genetic loci may exist; however, only a few have been recognized and characterized. Further investigation into the genetic etiology of POAG is expected to uncover novel and intriguing causal genes, allowing for a more precise pathogenesis pattern of the disease.
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Affiliation(s)
- Manoj Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, Harayana, India
| | - Aarti Bhardwaj
- Department of Genetics, Maharshi Dayanand University, Rohtak, Harayana, India
| | - Anshu Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, Harayana, India
| | - Rima Dada
- Department of Anatomy, AIIMS, New Delhi, India
| | - Mukesh Tanwar
- Department of Genetics, Maharshi Dayanand University, Rohtak, Harayana, India
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6
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Carmo-Silva S, Ferreira-Marques M, Nóbrega C, Botelho M, Costa D, Aveleira CA, Pulst SM, Pereira de Almeida L, Cavadas C. Ataxin-2 in the hypothalamus at the crossroads between metabolism and clock genes. J Mol Endocrinol 2023; 70:JME-21-0272. [PMID: 36103139 DOI: 10.1530/jme-21-0272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/14/2022] [Indexed: 01/19/2023]
Abstract
ATXN2 gene, encoding for ataxin-2, is located in a trait locus for obesity. Atxn2 knockout (KO) mice are obese and insulin resistant; however, the cause for this phenotype is still unknown. Moreover, several findings suggest ataxin-2 as a metabolic regulator, but the role of this protein in the hypothalamus was never studied before. The aim of this work was to understand if ataxin-2 modulation in the hypothalamus could play a role in metabolic regulation. Ataxin-2 was overexpressed/re-established in the hypothalamus of C57Bl6/Atxn2 KO mice fed either a chow or a high-fat diet (HFD). This delivery was achieved through stereotaxic injection of lentiviral vectors encoding for ataxin-2. We show, for the first time, that HFD decreases ataxin-2 levels in mouse hypothalamus and liver. Specific hypothalamic ataxin-2 overexpression prevents HFD-induced obesity and insulin resistance. Ataxin-2 re-establishment in Atxn2 KO mice improved metabolic dysfunction without changing body weight. Furthermore, we observed altered clock gene expression in Atxn2 KO that might be causative of metabolic dysfunction. Interestingly, ataxin-2 hypothalamic re-establishment rescued these circadian alterations. Thus, ataxin-2 in the hypothalamus is a determinant for weight, insulin sensitivity and clock gene expression. Ataxin-2's potential role in the circadian clock, through the regulation of clock genes, might be a relevant mechanism to regulate metabolism. Overall, this work shows hypothalamic ataxin-2 as a new player in metabolism regulation, which might contribute to the development of new strategies for metabolic disorders.
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Affiliation(s)
- Sara Carmo-Silva
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- MIA - Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Marisa Ferreira-Marques
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- ABC-RI, Algarve Biomedical Center Research Institute, Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve, Faro, Portugal
| | - Mariana Botelho
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Daniela Costa
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Célia A Aveleira
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- MIA - Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Luís Pereira de Almeida
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Claudia Cavadas
- CNC-UC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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7
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Palozzi JM, Jeedigunta SP, Minenkova AV, Monteiro VL, Thompson ZS, Lieber T, Hurd TR. Mitochondrial DNA quality control in the female germline requires a unique programmed mitophagy. Cell Metab 2022; 34:1809-1823.e6. [PMID: 36323236 DOI: 10.1016/j.cmet.2022.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/22/2022] [Accepted: 10/06/2022] [Indexed: 11/07/2022]
Abstract
Mitochondria have their own DNA (mtDNA), which is susceptible to the accumulation of disease-causing mutations. To prevent deleterious mutations from being inherited, the female germline has evolved a conserved quality control mechanism that remains poorly understood. Here, through a large-scale screen, we uncover a unique programmed germline mitophagy (PGM) that is essential for mtDNA quality control. We find that PGM is developmentally triggered as germ cells enter meiosis by inhibition of the target of rapamycin complex 1 (TORC1). We identify a role for the RNA-binding protein Ataxin-2 (Atx2) in coordinating the timing of PGM with meiosis. We show that PGM requires the mitophagy receptor BNIP3, mitochondrial fission and translation factors, and members of the Atg1 complex, but not the mitophagy factors PINK1 and Parkin. Additionally, we report several factors that are critical for germline mtDNA quality control and show that pharmacological manipulation of one of these factors promotes mtDNA quality control.
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Affiliation(s)
- Jonathan M Palozzi
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Swathi P Jeedigunta
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Anastasia V Minenkova
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Vernon L Monteiro
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Zoe S Thompson
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Toby Lieber
- HHMI and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Thomas R Hurd
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada.
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8
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Sundberg CA, Lakk M, Paul S, Figueroa KP, Scoles DR, Pulst SM, Križaj D. The RNA-binding protein and stress granule component ATAXIN-2 is expressed in mouse and human tissues associated with glaucoma pathogenesis. J Comp Neurol 2022; 530:537-552. [PMID: 34350994 PMCID: PMC8716417 DOI: 10.1002/cne.25228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/06/2021] [Indexed: 02/03/2023]
Abstract
Polyglutamine repeat expansions in the Ataxin-2 (ATXN2) gene were first implicated in Spinocerebellar Ataxia Type 2, a disease associated with degeneration of motor neurons and Purkinje cells. Recent studies linked single nucleotide polymorphisms in the gene to elevated intraocular pressure in primary open angle glaucoma (POAG); yet, the localization of ATXN2 across glaucoma-relevant tissues of the vertebrate eye has not been thoroughly examined. This study characterizes ATXN2 expression in the mouse and human retina, and anterior eye, using an antibody validated in ATXN2-/- retinas. ATXN2-ir was localized to cytosolic sub compartments in retinal ganglion cell (RGC) somata and proximal dendrites in addition to GABAergic, glycinergic, and cholinergic amacrine cells in the inner plexiform layer (IPL) and displaced amacrine cells. Human, but not mouse retinas showed modest immunolabeling of bipolar cells. ATXN2 immunofluorescence was prominent in the trabecular meshwork and pigmented and nonpigmented cells of the ciliary body, with analyses of primary human trabecular meshwork cells confirming the finding. The expression of ATXN2 in key POAG-relevant ocular tissues supports the potential role in autophagy and stress granule formation in response to ocular hypertension.
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Affiliation(s)
- Chad A. Sundberg
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Monika Lakk
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Karla P. Figueroa
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Daniel R. Scoles
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Stefan M. Pulst
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, Utah, USA
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9
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Song XH, He N, Xing YT, Jin XQ, Li YW, Liu SS, Gao ZY, Guo C, Wang JJ, Huang YY, Hu H, Wang LL. A Novel Age-Related Circular RNA Circ-ATXN2 Inhibits Proliferation, Promotes Cell Death and Adipogenesis in Rat Adipose Tissue-Derived Stromal Cells. Front Genet 2021; 12:761926. [PMID: 34858478 PMCID: PMC8630790 DOI: 10.3389/fgene.2021.761926] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/26/2021] [Indexed: 12/13/2022] Open
Abstract
Adipose tissue-derived stromal cells are promising candidates investigating the stem cell-related treatment. However, their proportion and utility in the human body decline with time, rendering stem cells incompetent to complete repair processes in vivo. The involvement of circRNAs in the aging process is poorly understood. Rat subcutaneous adipose tissue from 10-week-old and 27-month-old rats were used for hematoxylin and eosin (H and E) staining, TUNEL staining, and circRNA sequencing. Rat adipose tissue-derived stromal cells were cultured and overexpressed with circ-ATXN2. Proliferation was examined using xCELLigence real-time cell analysis, EdU staining, and cell cycle assay. Apoptosis was induced by CoCl2 and examined using flow cytometry. RT-PCR assay and Oil Red O staining were used to measure adipogenesis at 48 h and 14 days, respectively. H and E staining showed that the diameter of adipocytes increased; however, the number of cells decreased in old rats. TUNEL staining showed that the proportion of apoptotic cells was increased in old rats. A total of 4,860 and 4,952 circRNAs was detected in young and old rats, respectively. Among them, 67 circRNAs exhibited divergent expression between the two groups (fold change ≥2, p ≤ 0.05), of which 33 were upregulated (49.3%) and 34 were downregulated (50.7%). The proliferation of circ-ATXN2-overexpressing cells decreased significantly in vitro, which was further validated by xCELLigence real-time cell analysis, EdU staining, and cell cycle assay. Overexpression of circ-ATXN2 significantly increased the total apoptotic rate from 5.78 ± 0.46% to 11.97 ± 1.61%, early apoptotic rate from 1.76 ± 0.22% to 5.50 ± 0.66%, and late apoptosis rate from 4.02 ± 0.25% to 6.47 ± 1.06% in adipose tissue-derived stromal cells. Furthermore, in circ-ATXN2-overexpressing cells, RT-PCR assay revealed that the expression levels of adipose differentiation-related genes PPARγ and CEBP/α were increased and the Oil Red O staining assay showed more lipid droplets. Our study revealed the expression profile of circRNAs in the adipose tissue of old rats. We found a novel age-related circular RNA—circ-ATXN2—that inhibits proliferation and promotes cell death and adipogenesis in rat adipose tissue-derived stromal cells.
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Affiliation(s)
- Xing-Hui Song
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Ning He
- Department of Basic Medicine Sciences and Department of Orthopaedics of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yue-Ting Xing
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao-Qin Jin
- China Medical Research Center, Zhejiang Chinese Medical University Academy of Chinese Medical Sciences, Hangzhou, China
| | - Yan-Wei Li
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Shuang-Shuang Liu
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Zi-Ying Gao
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Chun Guo
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Jia-Jia Wang
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Ying-Ying Huang
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, China
| | - Hu Hu
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Lin-Lin Wang
- Department of Basic Medicine Sciences and Department of Orthopaedics of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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10
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McIntosh CS, Li D, Wilton SD, Aung-Htut MT. Polyglutamine Ataxias: Our Current Molecular Understanding and What the Future Holds for Antisense Therapies. Biomedicines 2021; 9:1499. [PMID: 34829728 PMCID: PMC8615177 DOI: 10.3390/biomedicines9111499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 02/07/2023] Open
Abstract
Polyglutamine (polyQ) ataxias are a heterogenous group of neurological disorders all caused by an expanded CAG trinucleotide repeat located in the coding region of each unique causative gene. To date, polyQ ataxias encompass six disorders: spinocerebellar ataxia types 1, 2, 3, 6, 7, and 17 and account for a larger group of disorders simply known as polyglutamine disorders, which also includes Huntington's disease. These diseases are typically characterised by progressive ataxia, speech and swallowing difficulties, lack of coordination and gait, and are unfortunately fatal in nature, with the exception of SCA6. All the polyQ spinocerebellar ataxias have a hallmark feature of neuronal aggregations and share many common pathogenic mechanisms, such as mitochondrial dysfunction, impaired proteasomal function, and autophagy impairment. Currently, therapeutic options are limited, with no available treatments that slow or halt disease progression. Here, we discuss the common molecular and clinical presentations of polyQ spinocerebellar ataxias. We will also discuss the promising antisense oligonucleotide therapeutics being developed as treatments for these devastating diseases. With recent advancements and therapeutic approvals of various antisense therapies, it is envisioned that some of the studies reviewed may progress into clinical trials and beyond.
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Affiliation(s)
- Craig S. McIntosh
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Dunhui Li
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Steve D. Wilton
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - May T. Aung-Htut
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
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11
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Charar C, Metsuyanim-Cohen S, Bar DZ. Lamin regulates the dietary restriction response via the mTOR pathway in Caenorhabditis elegans. J Cell Sci 2021; 134:272061. [PMID: 34383046 PMCID: PMC8445603 DOI: 10.1242/jcs.258428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/30/2021] [Indexed: 11/30/2022] Open
Abstract
Animals subjected to dietary restriction (DR) have reduced body size, low fecundity, slower development, lower fat content and longer life span. We identified lamin as a regulator of multiple dietary restriction phenotypes. Downregulation of lmn-1, the single Caenorhabditis elegans lamin gene, increased animal size and fat content specifically in DR animals. The LMN-1 protein acts in the mTOR pathway, upstream of RAPTOR and S6 kinase β1 (S6K), a key component of and target of the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1), respectively. DR excludes the mTORC1 activator RAGC-1 from the nucleus. Downregulation of lmn-1 restores RAGC-1 to the nucleus, a necessary step for the activation of the mTOR pathway. These findings further link lamin to metabolic regulation. Summary: Downregulation of the single C. elegans lamin gene increases animal size and fat content specifically in dietary restricted animals. The lamin protein acts in the mTOR pathway to regulate these phenotypes.
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Affiliation(s)
- Chayki Charar
- The School of Dental Medicine, The Faculty of Medicine, Tel Aviv University, Israel.,The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | | | - Daniel Z Bar
- The School of Dental Medicine, The Faculty of Medicine, Tel Aviv University, Israel
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12
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Amyotrophic Lateral Sclerosis: Molecular Mechanisms, Biomarkers, and Therapeutic Strategies. Antioxidants (Basel) 2021; 10:antiox10071012. [PMID: 34202494 PMCID: PMC8300638 DOI: 10.3390/antiox10071012] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/16/2021] [Accepted: 06/23/2021] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with the progressive loss of motor neurons, leading to a fatal paralysis. According to whether there is a family history of ALS, ALS can be roughly divided into two types: familial and sporadic. Despite decades of research, the pathogenesis of ALS is still unelucidated. To this end, we review the recent progress of ALS pathogenesis, biomarkers, and treatment strategies, mainly discuss the roles of immune disorders, redox imbalance, autophagy dysfunction, and disordered iron homeostasis in the pathogenesis of ALS, and introduce the effects of RNA binding proteins, ALS-related genes, and non-coding RNA as biomarkers on ALS. In addition, we also mention other ALS biomarkers such as serum uric acid (UA), cardiolipin (CL), chitotriosidase (CHIT1), and neurofilament light chain (NFL). Finally, we discuss the drug therapy, gene therapy, immunotherapy, and stem cell-exosomal therapy for ALS, attempting to find new therapeutic targets and strategies. A challenge is to study the various mechanisms of ALS as a syndrome. Biomarkers that have been widely explored are indispensable for the diagnosis, treatment, and prevention of ALS. Moreover, the development of new genes and targets is an urgent task in this field.
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13
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Marcelo A, Koppenol R, de Almeida LP, Matos CA, Nóbrega C. Stress granules, RNA-binding proteins and polyglutamine diseases: too much aggregation? Cell Death Dis 2021; 12:592. [PMID: 34103467 PMCID: PMC8187637 DOI: 10.1038/s41419-021-03873-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/25/2021] [Accepted: 05/25/2021] [Indexed: 02/05/2023]
Abstract
Stress granules (SGs) are membraneless cell compartments formed in response to different stress stimuli, wherein translation factors, mRNAs, RNA-binding proteins (RBPs) and other proteins coalesce together. SGs assembly is crucial for cell survival, since SGs are implicated in the regulation of translation, mRNA storage and stabilization and cell signalling, during stress. One defining feature of SGs is their dynamism, as they are quickly assembled upon stress and then rapidly dispersed after the stress source is no longer present. Recently, SGs dynamics, their components and their functions have begun to be studied in the context of human diseases. Interestingly, the regulated protein self-assembly that mediates SG formation contrasts with the pathological protein aggregation that is a feature of several neurodegenerative diseases. In particular, aberrant protein coalescence is a key feature of polyglutamine (PolyQ) diseases, a group of nine disorders that are caused by an abnormal expansion of PolyQ tract-bearing proteins, which increases the propensity of those proteins to aggregate. Available data concerning the abnormal properties of the mutant PolyQ disease-causing proteins and their involvement in stress response dysregulation strongly suggests an important role for SGs in the pathogenesis of PolyQ disorders. This review aims at discussing the evidence supporting the existence of a link between SGs functionality and PolyQ disorders, by focusing on the biology of SGs and on the way it can be altered in a PolyQ disease context.
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Affiliation(s)
- Adriana Marcelo
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- PhD Program in Biomedial Sciences, Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal
- Centre for Biomedical Research (CBMR), Universidade do Algarve, Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal
| | - Rebekah Koppenol
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- PhD Program in Biomedial Sciences, Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal
- Centre for Biomedical Research (CBMR), Universidade do Algarve, Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Carlos A Matos
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- Centre for Biomedical Research (CBMR), Universidade do Algarve, Faro, Portugal
- Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal
| | - Clévio Nóbrega
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- Centre for Biomedical Research (CBMR), Universidade do Algarve, Faro, Portugal.
- Faculty of Medicine and Biomedical Sciences, University of Algarve, Faro, Portugal.
- Champalimaud Research Program, Champalimaud Center for the Unknown, Lisbon, Portugal.
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14
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Mining the Royal Jelly Proteins: Combinatorial Hexapeptide Ligand Library Significantly Improves the MS-Based Proteomic Identification in Complex Biological Samples. MOLECULES (BASEL, SWITZERLAND) 2021; 26:molecules26092762. [PMID: 34067143 PMCID: PMC8125745 DOI: 10.3390/molecules26092762] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 12/18/2022]
Abstract
Royal jelly (RJ) is a complex, creamy secretion produced by the glands of worker bees. Due to its health-promoting properties, it is used by humans as a dietary supplement. However, RJ compounds are not fully characterized yet. Hence, in this research, we aimed to broaden the knowledge of the proteomic composition of fresh RJ. Water extracts of the samples were pre-treated using combinatorial hexapeptide ligand libraries (ProteoMinerTM kit), trypsin-digested, and analyzed by a nanoLC-MALDI-TOF/TOF MS system. To check the ProteoMinerTM performance in the MS-based protein identification, we also examined RJ extracts that were not prepared with the ProteoMinerTM kit. We identified a total of 86 proteins taxonomically classified to Apis spp. (bees). Among them, 74 proteins were detected in RJ extracts pre-treated with ProteoMinerTM kit, and only 50 proteins were found in extracts non-enriched with this technique. Ten of the identified features were hypothetical proteins whose existence has been predicted, but any experimental evidence proves their in vivo expression. Additionally, we detected four uncharacterized proteins of unknown functions. The results of this research indicate that the ProteoMinerTM strategy improves proteomic identification in complex biological samples. Broadening the knowledge of RJ composition may contribute to the development of standards and regulations, enhancing the quality of RJ, and consequently, the safety of its supplementation.
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15
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Theunissen F, Flynn LL, Anderton RS, Mastaglia F, Pytte J, Jiang L, Hodgetts S, Burns DK, Saunders A, Fletcher S, Wilton SD, Akkari PA. Structural Variants May Be a Source of Missing Heritability in sALS. Front Neurosci 2020; 14:47. [PMID: 32082115 PMCID: PMC7005198 DOI: 10.3389/fnins.2020.00047] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022] Open
Abstract
The underlying genetic and molecular mechanisms that drive amyotrophic lateral sclerosis (ALS) remain poorly understood. Structural variants within the genome can play a significant role in neurodegenerative disease risk, such as the repeat expansion in C9orf72 and the tri-nucleotide repeat in ATXN2, both of which are associated with familial and sporadic ALS. Many such structural variants reside in uncharacterized regions of the human genome, and have been under studied. Therefore, characterization of structural variants located in and around genes associated with ALS could provide insight into disease pathogenesis, and lead to the discovery of highly informative genetic tools for stratification in clinical trials. Such genomic variants may provide a deeper understanding of how gene expression can affect disease etiology, disease severity and trajectory, patient response to treatment, and may hold the key to understanding the genetics of sporadic ALS. This article outlines the current understanding of amyotrophic lateral sclerosis genetics and how structural variations may underpin some of the missing heritability of this disease.
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Affiliation(s)
- Frances Theunissen
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,School of Human Sciences, University of Western Australia, Nedlands, WA, Australia
| | - Loren L Flynn
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia
| | - Ryan S Anderton
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,School of Health Sciences, Institute for Health Research, University of Notre Dame Australia, Fremantle, WA, Australia
| | - Frank Mastaglia
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia
| | - Julia Pytte
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,School of Human Sciences, University of Western Australia, Nedlands, WA, Australia
| | - Leanne Jiang
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,School of Biological Sciences, University of Western Australia, Nedlands, WA, Australia
| | - Stuart Hodgetts
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,School of Human Sciences, University of Western Australia, Nedlands, WA, Australia
| | - Daniel K Burns
- Zinfandel Pharmaceuticals, Chapel Hill, NC, United States
| | - Ann Saunders
- Zinfandel Pharmaceuticals, Chapel Hill, NC, United States
| | - Sue Fletcher
- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia
| | - Steve D Wilton
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia
| | - Patrick Anthony Akkari
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia
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16
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Nunes C, Mestre I, Marcelo A, Koppenol R, Matos CA, Nóbrega C. MSGP: the first database of the protein components of the mammalian stress granules. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2019; 2019:5367298. [PMID: 30820574 PMCID: PMC6395795 DOI: 10.1093/database/baz031] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/14/2019] [Accepted: 02/11/2019] [Indexed: 01/09/2023]
Abstract
In response to different stress stimuli, cells transiently form stress granules (SGs) in order to protect themselves and re-establish homeostasis. Besides these important cellular functions, SGs are now being implicated in different human diseases, such as neurodegenerative disorders and cancer. SGs are ribonucleoprotein granules, constituted by a variety of different types of proteins, RNAs, factors involved in translation and signaling molecules, being capable of regulating mRNA translation to facilitate stress response. However, until now a complete list of the SG components has not been available. Therefore, we aimer at identifying and linting in an open access database all the proteins described so far as components of SGs. The identification was made through an exhaustive search of studies listed in PubMed and double checked. Moreover, for each identified protein several details were also gathered from public databases, such as the molecular function, the cell types in which they were detected, the type of stress stimuli used to induce SG formation and the reference of the study describing the recruitment of the component to SGs. Expression levels in the context of different neurodegenerative diseases were also obtained and are also described in the database. The Mammalian Stress Granules Proteome is available at https://msgp.pt/, being a new and unique open access online database, the first to list all the protein components of the SGs identified so far. The database constitutes an important and valuable tool for researchers in this research area of growing interest.
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Affiliation(s)
- Catarina Nunes
- Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Centre for Biomedical Research, University of Algarve, Faro, Portugal
| | - Isa Mestre
- Centre for Biomedical Research, University of Algarve, Faro, Portugal
| | - Adriana Marcelo
- Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Centre for Biomedical Research, University of Algarve, Faro, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rebekah Koppenol
- Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal
| | - Carlos A Matos
- Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Centre for Biomedical Research, University of Algarve, Faro, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Centre for Biomedical Research, University of Algarve, Faro, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Algarve Biomedical Center, University of Algarve, Faro, Portugal
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17
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Yeast Ataxin-2 Forms an Intracellular Condensate Required for the Inhibition of TORC1 Signaling during Respiratory Growth. Cell 2019; 177:697-710.e17. [PMID: 30982600 DOI: 10.1016/j.cell.2019.02.043] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 10/04/2018] [Accepted: 02/25/2019] [Indexed: 12/20/2022]
Abstract
Yeast ataxin-2, also known as Pbp1 (polyA binding protein-binding protein 1), is an intrinsically disordered protein implicated in stress granule formation, RNA biology, and neurodegenerative disease. To understand the endogenous function of this protein, we identify Pbp1 as a dedicated regulator of TORC1 signaling and autophagy under conditions that require mitochondrial respiration. Pbp1 binds to TORC1 specifically during respiratory growth, but utilizes an additional methionine-rich, low complexity (LC) region to inhibit TORC1. This LC region causes phase separation, forms reversible fibrils, and enables self-association into assemblies required for TORC1 inhibition. Mutants that weaken phase separation in vitro exhibit reduced capacity to inhibit TORC1 and induce autophagy. Loss of Pbp1 leads to mitochondrial dysfunction and reduced fitness during nutritional stress. Thus, Pbp1 forms a condensate in response to respiratory status to regulate TORC1 signaling.
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18
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Santos D, Coelho T, Alves-Ferreira M, Sequeiros J, Mendonça D, Alonso I, Sousa A, Lemos C. Large normal alleles of ATXN2
decrease age at onset in transthyretin familial amyloid polyneuropathy Val30Met patients. Ann Neurol 2019; 85:251-258. [DOI: 10.1002/ana.25409] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Diana Santos
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Teresa Coelho
- UCA, Unidade Corino de Andrade; Centro Hospitalar do Porto (CHP)
| | - Miguel Alves-Ferreira
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Jorge Sequeiros
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Denisa Mendonça
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
- ISPUP, Instituto de Saúde Pública; Universidade do Porto; Porto Portugal
| | - Isabel Alonso
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Alda Sousa
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Carolina Lemos
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
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19
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Zhao M, Kim JR, van Bruggen R, Park J. RNA-Binding Proteins in Amyotrophic Lateral Sclerosis. Mol Cells 2018; 41:818-829. [PMID: 30157547 PMCID: PMC6182225 DOI: 10.14348/molcells.2018.0243] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/23/2018] [Accepted: 08/10/2018] [Indexed: 12/11/2022] Open
Abstract
Significant research efforts are ongoing to elucidate the complex molecular mechanisms underlying amyotrophic lateral sclerosis (ALS), which may in turn pinpoint potential therapeutic targets for treatment. The ALS research field has evolved with recent discoveries of numerous genetic mutations in ALS patients, many of which are in genes encoding RNA binding proteins (RBPs), including TDP-43, FUS, ATXN2, TAF15, EWSR1, hnRNPA1, hnRNPA2/B1, MATR3 and TIA1. Accumulating evidence from studies on these ALS-linked RBPs suggests that dysregulation of RNA metabolism, cytoplasmic mislocalization of RBPs, dysfunction in stress granule dynamics of RBPs and increased propensity of mutant RBPs to aggregate may lead to ALS pathogenesis. Here, we review current knowledge of the biological function of these RBPs and the contributions of ALS-linked mutations to disease pathogenesis.
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Affiliation(s)
- Melody Zhao
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto,
Canada
- Department of Molecular Genetics, University of Toronto, Toronto,
Canada
| | - Jihye Rachel Kim
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto,
Canada
- Department of Molecular Genetics, University of Toronto, Toronto,
Canada
| | - Rebekah van Bruggen
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto,
Canada
| | - Jeehye Park
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto,
Canada
- Department of Molecular Genetics, University of Toronto, Toronto,
Canada
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20
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Repeat length variations in polyglutamine disease-associated genes affect body mass index. Int J Obes (Lond) 2018; 43:440-449. [PMID: 30120431 DOI: 10.1038/s41366-018-0161-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/15/2018] [Accepted: 06/15/2018] [Indexed: 11/08/2022]
Abstract
BACKGROUND The worldwide prevalence of obesity, a major risk factor for numerous debilitating chronic disorders, is increasing rapidly. Although a substantial amount of the variation in body mass index (BMI) is estimated to be heritable, the largest meta-analysis of genome-wide association studies (GWAS) to date explained only ~2.7% of the variation. To tackle this 'missing heritability' problem of obesity, here we focused on the contribution of DNA repeat length polymorphisms which are not detectable by GWAS. SUBJECTS AND METHODS We determined the cytosine-adenine-guanine (CAG) repeat length in the nine known polyglutamine disease-associated genes (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP, HTT, ATN1 and AR) in two large cohorts consisting of 12,457 individuals and analyzed their association with BMI, using generalized linear mixed-effect models. RESULTS We found a significant association between BMI and the length of CAG repeats in seven polyglutamine disease-associated genes (including ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP and AR). Importantly, these repeat variations could account for 0.75% of the total BMI variation. CONCLUSIONS Our findings incriminate repeat polymorphisms as an important novel class of genetic risk factors of obesity and highlight the role of the brain in its pathophysiology.
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21
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Lee J, Kim M, Itoh TQ, Lim C. Ataxin-2: A versatile posttranscriptional regulator and its implication in neural function. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1488. [PMID: 29869836 DOI: 10.1002/wrna.1488] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/04/2018] [Accepted: 05/09/2018] [Indexed: 12/13/2022]
Abstract
Ataxin-2 (ATXN2) is a eukaryotic RNA-binding protein that is conserved from yeast to human. Genetic expansion of a poly-glutamine tract in human ATXN2 has been implicated in several neurodegenerative diseases, likely acting through gain-of-function effects. Emerging evidence, however, suggests that ATXN2 plays more direct roles in neural function via specific molecular and cellular pathways. ATXN2 and its associated protein complex control distinct steps in posttranscriptional gene expression, including poly-A tailing, RNA stabilization, microRNA-dependent gene silencing, and translational activation. Specific RNA substrates have been identified for the functions of ATXN2 in aspects of neural physiology, such as circadian rhythms and olfactory habituation. Genetic models of ATXN2 loss-of-function have further revealed its significance in stress-induced cytoplasmic granules, mechanistic target of rapamycin signaling, and cellular metabolism, all of which are crucial for neural homeostasis. Accordingly, we propose that molecular evolution has been selecting the ATXN2 protein complex as an important trans-acting module for the posttranscriptional control of diverse neural functions. This explains how ATXN2 intimately interacts with various neurodegenerative disease genes, and suggests that loss-of-function effects of ATXN2 could be therapeutic targets for ATXN2-related neurological disorders. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Jongbo Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Minjong Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Taichi Q Itoh
- Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
| | - Chunghun Lim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
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22
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Squadrone S, Brizio P, Mancini C, Abete MC, Brusco A. Altered homeostasis of trace elements in the blood of SCA2 patients. J Trace Elem Med Biol 2018; 47:111-114. [PMID: 29544796 DOI: 10.1016/j.jtemb.2018.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 01/03/2023]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is a neurological disorder characterized by cerebellar dysfunction. The possible association between metals and neurodegenerative diseases is under constant investigation, with particular focus on their involvement in oxidative stress and their potential role as biomarkers of these pathologies. Whole blood samples of SCA2 patients and of healthy individuals were subjected to multi-elemental analysis by inductively coupled plasma-mass spectrometry (ICP-MS). Reduced levels of manganese and copper were found in SCA2 patients, while zinc and vanadium concentrations were significantly higher in patients compared to controls. Copper, manganese and zinc are cofactors of many enzymes (such as superoxide dismutase, SOD) involved in the cellular antioxidant response, whereas vanadium is a transition metal able to produce reactive radicals. A marked decrease of the antioxidant response has been previously reported in SCA2 patients. We suggest that an unbalance of transitional elements in the blood may reflect altered antioxidant homeostasis in SCA2 patients and could constitute a future peripheral biomarker for this disease. In addition, we suggest a possible role of vanadium in the altered lipid metabolism of SCA2 patients.
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Affiliation(s)
- Stefania Squadrone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy.
| | - Paola Brizio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - Cecilia Mancini
- University of Torino, Department of Medical Sciences, 10126 Torino, Italy
| | - Maria Cesarina Abete
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna 148, 10154 Torino, Italy
| | - Alfredo Brusco
- University of Torino, Department of Medical Sciences, 10126 Torino, Italy; Città della Salute e della Scienza University Hospital, Medical Genetics Unit, 10126 Torino, Italy
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23
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Moskalev A, Shaposhnikov M, Zemskaya N, Belyi A, Dobrovolskaya E, Patova A, Guvatova Z, Lukyanova E, Snezhkina A, Kudryavtseva A. Transcriptome analysis reveals mechanisms of geroprotective effects of fucoxanthin in Drosophila. BMC Genomics 2018; 19:77. [PMID: 29504896 PMCID: PMC5836829 DOI: 10.1186/s12864-018-4471-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background We have previously showed that the carotenoid fucoxanthin can increase the lifespan in Drosophila melanogaster and Caenorhabditis elegans. However, the molecular mechanisms of the geroprotective effect of fucoxanthin have not been studied so far. Results Here, we studied the effects of fucoxanthin on the Drosophila aging process at the molecular and the whole organism levels. At the organismal level, fucoxanthin increased the median lifespan and had a positive effect on fecundity, fertility, intestinal barrier function, and nighttime sleep. Transcriptome analysis revealed 57 differentially expressed genes involved in 17 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. Among the most represented molecular pathways induced by fucoxanthin, a significant portion is related to longevity, including MAPK, mTOR, Wnt, Notch, and Hippo signaling pathways, autophagy, translation, glycolysis, oxidative phosphorylation, apoptosis, immune response, neurogenesis, sleep, and response to DNA damage. Conclusions Life-extending effects of fucoxanthin are associated with differential expression of longevity-associated genes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4471-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alexey Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia. .,Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia.
| | - Mikhail Shaposhnikov
- Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
| | - Nadezhda Zemskaya
- Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
| | - Alexey Belyi
- Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
| | - Eugenia Dobrovolskaya
- Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
| | - Anna Patova
- Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
| | - Zulfiya Guvatova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Elena Lukyanova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anastasiya Snezhkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Kudryavtseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
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24
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Velázquez-Pérez LC, Rodríguez-Labrada R, Fernandez-Ruiz J. Spinocerebellar Ataxia Type 2: Clinicogenetic Aspects, Mechanistic Insights, and Management Approaches. Front Neurol 2017; 8:472. [PMID: 28955296 PMCID: PMC5601978 DOI: 10.3389/fneur.2017.00472] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/25/2017] [Indexed: 12/14/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant cerebellar ataxia that occurs as a consequence of abnormal CAG expansions in the ATXN2 gene. Progressive clinical features result from the neurodegeneration of cerebellum and extra-cerebellar structures including the pons, the basal ganglia, and the cerebral cortex. Clinical, electrophysiological, and imaging approaches have been used to characterize the natural history of the disease, allowing its classification into four distinct stages, with special emphasis on the prodromal stage, which is characterized by a plethora of motor and non-motor features. Neuropathological investigations of brain tissue from SCA2 patients reveal a widespread involvement of multiple brain systems, mainly cerebellar and brainstem systems. Recent findings linking ataxin-2 intermediate expansions to other neurodegenerative diseases such as amyotrophic lateral sclerosis have provided insights into the ataxin-2-related toxicity mechanism in neurodegenerative diseases and have raised new ethical challenges to molecular predictive diagnosis of SCA2. No effective neuroprotective therapies are currently available for SCA2 patients, but some therapeutic options such as neurorehabilitation and some emerging neuroprotective drugs have shown palliative benefits.
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Affiliation(s)
- Luis C Velázquez-Pérez
- Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba.,Medical University of Holguín "Mariana Grajales", Holguín, Cuba
| | - Roberto Rodríguez-Labrada
- Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba.,Physical Culture School, University of Holguin "Oscar Lucero", Holguín, Cuba
| | - Juan Fernandez-Ruiz
- Department of Physiology, Medicine School, UNAM, Cuernavaca, Mexico.,Psychology School, Universidad Veracruzana, Xalapa, Mexico
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25
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Ataxin-2: From RNA Control to Human Health and Disease. Genes (Basel) 2017; 8:genes8060157. [PMID: 28587229 PMCID: PMC5485521 DOI: 10.3390/genes8060157] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/23/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022] Open
Abstract
RNA-binding proteins play fundamental roles in the regulation of molecular processes critical to cellular and organismal homeostasis. Recent studies have identified the RNA-binding protein Ataxin-2 as a genetic determinant or risk factor for various diseases including spinocerebellar ataxia type II (SCA2) and amyotrophic lateral sclerosis (ALS), amongst others. Here, we first discuss the increasingly wide-ranging molecular functions of Ataxin-2, from the regulation of RNA stability and translation to the repression of deleterious accumulation of the RNA-DNA hybrid-harbouring R-loop structures. We also highlight the broader physiological roles of Ataxin-2 such as in the regulation of cellular metabolism and circadian rhythms. Finally, we discuss insight from clinically focused studies to shed light on the impact of molecular and physiological roles of Ataxin-2 in various human diseases. We anticipate that deciphering the fundamental functions of Ataxin-2 will uncover unique approaches to help cure or control debilitating and lethal human diseases.
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