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Sharma S, Singh G, Patwardhan K. Effects of two Ayurvedic formulations, Dhanwantaram Kashaya and Saraswatarishta on life history parameters and toxic aggregates in Drosophila models of Huntington's and Alzheimer's disease. JOURNAL OF ETHNOPHARMACOLOGY 2023; 305:116080. [PMID: 36603787 DOI: 10.1016/j.jep.2022.116080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/10/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ayurveda, the traditional healthcare system native to India, employs dosage forms containing multiple herbs in treating various clinical conditions. Dhanwantaram Kashaya (DK) and Saraswatarishta (SA) are two such formulations containing multiple herbs in varied proportions. Kashaya is a liquid decoction while Arishta is fermented liquid with permissible quantity of self-generated alcohol in it. Both the formulations have been reported to have clinical efficacy in age-related memory impairment. Other mental disorders having clinical presentations similar to psychoses are the other indications for these tested formulations. AIM OF THE STUDY The present study was performed to evaluate the efficacy of two Rasayana formulations i.e., DK and SA, used by clinicians in different neurodegenerative conditions. We tested these formulations in Alzheimer's (AD) and Huntington's disease (HD) models of Drosophila melanogaster. MATERIALS AND METHOD Initial experiments looking for life-history parameters in wild-type larvae were carried out in three sets with hundred larvae in each set. These parameters were also studied in diseased models in four sets with eighty larvae in each set. Aβ plaques and polyQ aggregates were looked at with the help of immunostaining technique and images were captured using confocal microscopy. RESULTS The results revealed that 0.25% concentration of both the formulations improve longevity in wild-type flies. Larval development and adult lifespan in Eye-GAL4>Aβ42 (AD) and GMR-GAL4>127Q (HD) larvae/flies reared on 0.25% & 0.50% DK and 0.25% & 1.00% SA improved substantially. Reduced Aβ plaques and polyQ aggregates indicate disease suppression. CONCLUSION DK and SA enhanced longevity in Drosophila melanogaster. Suppression of disease aggregates suggests their potential utility in treating AD and HD. Further clinical and pharmaceutical studies are required to confirm these results, however, this is a workable model to test multi-herbal formulations of Ayurveda in the forms they are clinically used.
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Affiliation(s)
- Swati Sharma
- Department of Kriya Sharir, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
| | - Girish Singh
- Centre of Biostatistics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
| | - Kishor Patwardhan
- Department of Kriya Sharir, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
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Singh AK. Hsrω and Other lncRNAs in Neuronal Functions and Disorders in Drosophila. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010017. [PMID: 36675966 PMCID: PMC9865238 DOI: 10.3390/life13010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/27/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
Long noncoding RNAs (lncRNAs) have a crucial role in epigenetic, transcriptional and posttranscriptional regulation of gene expression. Many of these regulatory lncRNAs, such as MALAT1, NEAT1, HOTAIR, etc., are associated with different neurodegenerative diseases in humans. The lncRNAs produced by the hsrω gene are known to modulate neurotoxicity in polyQ and amyotrophic lateral sclerosis disease models of Drosophila. Elevated expression of hsrω lncRNAs exaggerates, while their genetic depletion through hsrω-RNAi or in an hsrω-null mutant background suppresses, the disease pathogenicity. This review discusses the possible mechanistic details and implications of the functions of hsrω lncRNAs in the modulation of neurodegenerative diseases.
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Affiliation(s)
- Anand Kumar Singh
- Interdisciplinary School of Life Sciences, Institute of Science, Banaras Hindu University, Varanasi 221005, India
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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: 63] [Impact Index Per Article: 21.0] [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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Nelson VK, Ali A, Dutta N, Ghosh S, Jana M, Ganguli A, Komarov A, Paul S, Dwivedi V, Chatterjee S, Jana NR, Lakhotia SC, Chakrabarti G, Misra AK, Mandal SC, Pal M. Azadiradione ameliorates polyglutamine expansion disease in Drosophila by potentiating DNA binding activity of heat shock factor 1. Oncotarget 2018; 7:78281-78296. [PMID: 27835876 PMCID: PMC5346638 DOI: 10.18632/oncotarget.12930] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/21/2016] [Indexed: 01/14/2023] Open
Abstract
Aggregation of proteins with the expansion of polyglutamine tracts in the brain underlies progressive genetic neurodegenerative diseases (NDs) like Huntington's disease and spinocerebellar ataxias (SCA). An insensitive cellular proteotoxic stress response to non-native protein oligomers is common in such conditions. Indeed, upregulation of heat shock factor 1 (HSF1) function and its target protein chaperone expression has shown promising results in animal models of NDs. Using an HSF1 sensitive cell based reporter screening, we have isolated azadiradione (AZD) from the methanolic extract of seeds of Azadirachta indica, a plant known for its multifarious medicinal properties. We show that AZD ameliorates toxicity due to protein aggregation in cell and fly models of polyglutamine expansion diseases to a great extent. All these effects are correlated with activation of HSF1 function and expression of its target protein chaperone genes. Notably, HSF1 activation by AZD is independent of cellular HSP90 or proteasome function. Furthermore, we show that AZD directly interacts with purified human HSF1 with high specificity, and facilitates binding of HSF1 to its recognition sequence with higher affinity. These unique findings qualify AZD as an ideal lead molecule for consideration for drug development against NDs that affect millions worldwide.
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Affiliation(s)
- Vinod K Nelson
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India.,Department of Pharmaceutical Technology, Pharmacognosy and Phytotherapy Laboratory, Jadavpur University, Jadavpur, West Bengal, India
| | - Asif Ali
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Naibedya Dutta
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Suvranil Ghosh
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Manas Jana
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Arnab Ganguli
- Dr. B. C. Guha Center for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal, India
| | - Andrei Komarov
- Cellecta Inc, Mountain View, California, United States of America
| | - Soumyadip Paul
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Vibha Dwivedi
- Department of Zoology, Cytogenetics Laboratory, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | | | - Nihar R Jana
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Institute, Manesar, Gurgaon, Haryana, India
| | - Subhash C Lakhotia
- Department of Zoology, Cytogenetics Laboratory, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Gopal Chakrabarti
- Dr. B. C. Guha Center for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal, India
| | - Anup K Misra
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
| | - Subhash C Mandal
- Department of Pharmaceutical Technology, Pharmacognosy and Phytotherapy Laboratory, Jadavpur University, Jadavpur, West Bengal, India
| | - Mahadeb Pal
- Division of Molecular Medicine, Bose Institute, Kolkata, West Bengal, India
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Lin L, Jin Z, Tan H, Xu Q, Peng T, Li H. Atypical ubiquitination by E3 ligase WWP1 inhibits the proteasome-mediated degradation of mutant huntingtin. Brain Res 2016; 1643:103-12. [PMID: 27107943 DOI: 10.1016/j.brainres.2016.03.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/10/2016] [Accepted: 03/18/2016] [Indexed: 11/19/2022]
Abstract
Huntington's disease (HD) is caused by the expansion of CAG trinucleotide repeats in exon 1 of HD gene encoding huntingtin (Htt), which is characterized by aggregation and formation of mutant Htt containing expanded polyglutamine (polyQ) repeats. Dysfunction of the ubiquitin-proteasome system (UPS) plays a critical role in the pathogenesis of HD. As the linkage mediator between ubiquitin and specific target proteins, E3 ubiquitin ligases have been suggested to be involved in mHtt degradation and HD pathology. However, the potential involvement of the E3 ligase WWP1 in HD has not been explored. The present study determined whether WWP1 is involved in the development of HD in both in vivo and in vitro models. The results showed that in contrast to several other E3 ligases, expression of WWP1 is enhanced in mice and N2a cells expressing mutant Htt (160Q) and co-localized with mHtt protein aggregates. In addition, expression of WWP1 positively regulates mutan Htt levels, aggregate formation, and cell toxicity. Further analysis revealed that WWP1 ubiquitinated mHtt at an atypical position of Lys-63, which may have inhibited degradation of mutant Htt through the ubiquitin-proteasome pathway. In conclusion, these results suggested that the E3 ligase WWP1 is involved in the pathogenesis of HD; therefore, it may be a novel target for therapeutic intervention.
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Affiliation(s)
- Li Lin
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Zhenzhen Jin
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Huiping Tan
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Qiaoqiao Xu
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Ting Peng
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; (b)Key Laboratory for Neurological Disorders of Education Ministry,Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; (c)Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
| | - He Li
- Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; (b)Key Laboratory for Neurological Disorders of Education Ministry,Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; (c)Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
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Kumar A, Singh PK, Parihar R, Dwivedi V, Lakhotia SC, Ganesh S. Decreased O-linked GlcNAcylation protects from cytotoxicity mediated by huntingtin exon1 protein fragment. J Biol Chem 2014; 289:13543-53. [PMID: 24648514 DOI: 10.1074/jbc.m114.553321] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
O-GlcNAcylation is an important post-translational modification of proteins and is known to regulate a number of pathways involved in cellular homeostasis. This involves dynamic and reversible modification of serine/threonine residues of different cellular proteins catalyzed by O-linked N-acetylglucosaminyltransferase and O-linked N-acetylglucosaminidase in an antagonistic manner. We report here that decreasing O-GlcNAcylation enhances the viability of neuronal cells expressing polyglutamine-expanded huntingtin exon 1 protein fragment (mHtt). We further show that O-GlcNAcylation regulates the basal autophagic process and that suppression of O-GlcNAcylation significantly increases autophagic flux by enhancing the fusion of autophagosome with lysosome. This regulation considerably reduces toxic mHtt aggregates in eye imaginal discs and partially restores rhabdomere morphology and vision in a fly model for Huntington disease. This study is significant in unraveling O-GlcNAcylation-dependent regulation of an autophagic process in mediating mHtt toxicity. Therefore, targeting the autophagic process through the suppression of O-GlcNAcylation may prove to be an important therapeutic approach in Huntington disease.
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Affiliation(s)
- Amit Kumar
- From the Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016 and
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8
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Mehanna R, Itin I. From normal gait to loss of ambulation in 6 months: a novel presentation of SCA17. THE CEREBELLUM 2014; 12:568-71. [PMID: 23475385 DOI: 10.1007/s12311-013-0466-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Spinocerebellar ataxias are a group of rare and heterogeneous autosomal dominant disorders characterized by progressive ataxia and other features. Spinocerebellar ataxia 17 (SCA17) is one of the 32 subtypes described to date and is secondary to CAG/CAA repeat expansion in the gene coding for the TATA-box binding protein (TBP). SCA17 is clinically heterogeneous and typically presents with slowly evolving ataxia, dysarthria, dementia, depression, and other movement disorders such as chorea. More than 41 CAG/CAA repeats are considered diagnostic of SCA17, with more than 49 being associated with full penetrance. We report one patient presenting with isolated rapidly evolving ataxia who was found to have 44 CAG/CAA repeats in the TBP gene. This suggests that, while SCA17 typically slowly progresses over years, its repertoire of presentations should be expanded to include rapidly progressive isolated ataxia resembling paraneoplastic disorders or prion disease.
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Affiliation(s)
- R Mehanna
- Center for Neurological Restoration, Cleveland Clinic Foundation, 9500 Euclid Avenue/U20, Cleveland, OH 44195, USA.
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Singh MD, Raj K, Sarkar S. Drosophila Myc, a novel modifier suppresses the poly(Q) toxicity by modulating the level of CREB binding protein and histone acetylation. Neurobiol Dis 2013; 63:48-61. [PMID: 24291519 DOI: 10.1016/j.nbd.2013.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/06/2013] [Accepted: 11/19/2013] [Indexed: 12/18/2022] Open
Abstract
Polyglutamine or poly(Q) disorders are dominantly inherited neurodegenerative diseases characterised by progressive loss of neurons in cerebellum, basal ganglia and cortex in adult human brain. Overexpression of human form of mutant SCA3 protein with 78 poly(Q) repeats leads to the formation of inclusion bodies and increases the cellular toxicity in Drosophila eye. The present study was directed to identify a genetic modifier of poly(Q) diseases that could be utilised as a potential drug target. The initial screening process was influenced by the fact of lower prevalence of cancer among patients suffering with poly(Q) disorders which appears to be related to the intrinsic biological factors. We investigated if Drosophila Myc (a homologue of human cMyc proto-oncogene) harbours intrinsic property of suppressing cellular toxicity induced by an abnormally long stretch of poly(Q). We show for the first time that targeted overexpression of Drosophila Myc (dMyc) mitigates the poly(Q) toxicity in eye and nervous systems. Upregulation of dMyc results in a significant reduction in accumulation of inclusion bodies with residual poly(Q) aggregates localising into cytoplasm. We demonstrate that dMyc mediated suppression of poly(Q) toxicity is achieved by alleviating the cellular level of CBP and improved histone acetylation, resulting restoration of transcriptional machinery which are otherwise abbreviated due to poly(Q) disease conditions. Moreover, our study also provides a rational justification of the enigma of poly(Q) patients showing resistance to the predisposition of cancer.
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Affiliation(s)
- M Dhruba Singh
- Department of Genetics, University of Delhi, South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Kritika Raj
- Department of Genetics, University of Delhi, South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi, South Campus, Benito Juarez Road, New Delhi 110 021, India.
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Na D, Rouf M, O'Kane CJ, Rubinsztein DC, Gsponer J. NeuroGeM, a knowledgebase of genetic modifiers in neurodegenerative diseases. BMC Med Genomics 2013; 6:52. [PMID: 24229347 PMCID: PMC3833180 DOI: 10.1186/1755-8794-6-52] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 11/08/2013] [Indexed: 11/26/2022] Open
Abstract
Background Neurodegenerative diseases (NDs) are characterized by the progressive loss of neurons in the human brain. Although the majority of NDs are sporadic, evidence is accumulating that they have a strong genetic component. Therefore, significant efforts have been made in recent years to not only identify disease-causing genes but also genes that modify the severity of NDs, so-called genetic modifiers. To date there exists no compendium that lists and cross-links genetic modifiers of different NDs. Description In order to address this need, we present NeuroGeM, the first comprehensive knowledgebase providing integrated information on genetic modifiers of nine different NDs in the model organisms D. melanogaster, C. elegans, and S. cerevisiae. NeuroGeM cross-links curated genetic modifier information from the different NDs and provides details on experimental conditions used for modifier identification, functional annotations, links to homologous proteins and color-coded protein-protein interaction networks to visualize modifier interactions. We demonstrate how this database can be used to generate new understanding through meta-analysis. For instance, we reveal that the Drosophila genes DnaJ-1, thread, Atx2, and mub are generic modifiers that affect multiple if not all NDs. Conclusion As the first compendium of genetic modifiers, NeuroGeM will assist experimental and computational scientists in their search for the pathophysiological mechanisms underlying NDs. http://chibi.ubc.ca/neurogem.
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Affiliation(s)
| | | | | | | | - Jörg Gsponer
- Department of Biochemistry and Molecular Biology, Centre for High-throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC V6T 1Z4, Canada.
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Abstract
Poly-glutamine (polyQ) diseases are neurodegenerative disorders characterised by expanded CAG repeats in the causative genes whose proteins form inclusion bodies. Various E3 ubiquitin ligases are implicated in neurodegenerative disorders. We report that dysfunction of the SCF (Skp1-Cul1-F-box protein) complex, one of the most well-characterised ubiquitin ligases, is associated with pathology in polyQ diseases like Huntington's disease (HD) and Machado–Joseph disease (MJD). We found that Cullin1 (Cul1) and Skp1, core components of the SCF complex, are reduced in HD mice brain. A reduction in Cul1 levels was also observed in cellular HD model and fly models of both HD and MJD. We show that Cul1 is able to genetically modify mutant huntingtin aggregates because its silencing results in increased aggregate load in cultured cells. Moreover, we demonstrate that silencing dCul1 and dSkp1 in Drosophila results in increased aggregate load and enhanced polyQ-induced toxicity. Our results imply that reduced levels of SCF complex might contribute to polyQ disease pathology.
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Jaiswal M, Sandoval H, Zhang K, Bayat V, Bellen HJ. Probing mechanisms that underlie human neurodegenerative diseases in Drosophila. Annu Rev Genet 2012; 46:371-96. [PMID: 22974305 DOI: 10.1146/annurev-genet-110711-155456] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The fruit fly, Drosophila melanogaster, is an excellent organism for the study of the genetic and molecular basis of metazoan development. Drosophila provides numerous tools and reagents to unravel the molecular and cellular functions of genes that cause human disease, and the past decade has witnessed a significant expansion of the study of neurodegenerative disease mechanisms in flies. Here we review the interplay between oxidative stress and neuronal toxicity. We cover some of the studies that show how proteasome degradation of protein aggregates, autophagy, mitophagy, and lysosomal function affect the quality control mechanisms required for neuronal survival. We discuss how forward genetic screens in flies have led to the isolation of a few loci that cause neurodegeneration, paving the way for large-scale systematic screens to identify such loci in flies as well as promoting gene discovery in humans.
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Affiliation(s)
- M Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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Nielsen TT, Mardosiene S, Løkkegaard A, Stokholm J, Ehrenfels S, Bech S, Friberg L, Nielsen JK, Nielsen JE. Severe and rapidly progressing cognitive phenotype in a SCA17-family with only marginally expanded CAG/CAA repeats in the TATA-box binding protein gene: a case report. BMC Neurol 2012; 12:73. [PMID: 22889412 PMCID: PMC3475097 DOI: 10.1186/1471-2377-12-73] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 08/06/2012] [Indexed: 11/17/2022] Open
Abstract
Background The autosomal dominant spinocerebellar ataxias (SCAs) confine a group of rare and heterogeneous disorders, which present with progressive ataxia and numerous other features e.g. peripheral neuropathy, macular degeneration and cognitive impairment, and a subset of these disorders is caused by CAG-repeat expansions in their respective genes. The diagnosing of the SCAs is often difficult due to the phenotypic overlap among several of the subtypes and with other neurodegenerative disorders e.g. Huntington’s disease. Case presentation We report a family in which the proband had rapidly progressing cognitive decline and only subtle cerebellar symptoms from age 42. Sequencing of the TATA-box binding protein gene revealed a modest elongation of the CAG/CAA-repeat of only two repeats above the non-pathogenic threshold of 41, confirming a diagnosis of SCA17. Normally, repeats within this range show reduced penetrance and result in a milder disease course with slower progression and later age of onset. Thus, this case presented with an unusual phenotype. Conclusions The current case highlights the diagnostic challenge of neurodegenerative disorders and the need for a thorough clinical and paraclinical examination of patients presenting with rapid cognitive decline to make a precise diagnosis on which further genetic counseling and initiation of treatment modalities can be based.
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Affiliation(s)
- Troels Tolstrup Nielsen
- Memory Disorders Research Group, Neurogenetics Clinic, Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
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Rincon-Limas DE, Jensen K, Fernandez-Funez P. Drosophila models of proteinopathies: the little fly that could. Curr Pharm Des 2012; 18:1108-22. [PMID: 22288402 PMCID: PMC3290773 DOI: 10.2174/138161212799315894] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 12/19/2011] [Indexed: 02/08/2023]
Abstract
Alzheimer’s, Parkinson’s, and Huntington’s disease are complex neurodegenerative conditions with high prevalence characterized by protein misfolding and deposition in the brain. Considerable progress has been made in the last two decades in identifying the genes and proteins responsible for several human ‘proteinopathies’. A wide variety of wild type and mutant proteins associated with neurodegenerative conditions are structurally unstable, misfolded, and acquire conformations rich in ß-sheets (ß-state). These conformers form highly toxic self-assemblies that kill the neurons in stereotypical patterns. Unfortunately, the detailed understanding of the molecular and cellular perturbations caused by these proteins has not produced a single disease-modifying therapy. More than a decade ago, several groups demonstrated that human proteinopathies reproduce critical features of the disease in transgenic flies, including protein misfolding, aggregation, and neurotoxicity. These initial reports led to an explosion of research that has contributed to a better understanding of the molecular mechanisms regulating conformational dynamics and neurotoxic cascades. To remain relevant in this competitive environment, Drosophila models will need to expand their flexible, innovative, and multidisciplinary approaches to find new discoveries and translational applications.
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Affiliation(s)
- Diego E Rincon-Limas
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0236, USA.
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Dwivedi V, Anandan EM, Mony RS, Muraleedharan TS, Valiathan MS, Mutsuddi M, Lakhotia SC. In vivo effects of traditional Ayurvedic formulations in Drosophila melanogaster model relate with therapeutic applications. PLoS One 2012; 7:e37113. [PMID: 22606337 PMCID: PMC3351451 DOI: 10.1371/journal.pone.0037113] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 04/13/2012] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Ayurveda represents the traditional medicine system of India. Since mechanistic details of therapy in terms of current biology are not available in Ayurvedic literature, modern scientific studies are necessary to understand its major concepts and procedures. It is necessary to examine effects of the whole Ayurvedic formulations rather than their "active" components as is done in most current studies. METHODS We tested two different categories of formulations, a Rasayana (Amalaki Rasayana or AR, an herbal derivative) and a Bhasma (Rasa-Sindoor or RS, an organo-metallic derivative of mercury), for effects on longevity, development, fecundity, stress-tolerance, and heterogeneous nuclear ribonucleoprotein (hnRNP) levels of Drosophila melanogaster using at least 200 larvae or flies for each assay. RESULTS A 0.5% (weight/volume) supplement of AR or RS affected life-history and other physiological traits in distinct ways. While the size of salivary glands, hnRNP levels in larval tissues, and thermotolerance of larvae/adult flies improved significantly following feeding either of the two formulations, the median life span and starvation resistance improved only with AR. Feeding on AR or RS supplemented food improved fecundity differently. Feeding of larvae and adults with AR increased the fecundity while the same with RS had opposite effect. On the contrary, feeding larvae on normal food and adults on AR supplement had no effect on fecundity but a comparable regime of feeding on RS-supplemented food improved fecundity. RS feeding did not cause heavy metal toxicity. CONCLUSIONS The present study with two Ayurvedic formulations reveals formulation-specific effects on several parameters of the fly's life, which seem to generally agree with their recommended human usages in Ayurvedic practices. Thus, Drosophila, with its very rich genetic tools and well-worked-out developmental pathways promises to be a very good model for examining the cellular and molecular bases of the effects of different Ayurvedic formulations.
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Affiliation(s)
- Vibha Dwivedi
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
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Chen X, Burgoyne RD. Identification of common genetic modifiers of neurodegenerative diseases from an integrative analysis of diverse genetic screens in model organisms. BMC Genomics 2012; 13:71. [PMID: 22333271 PMCID: PMC3292922 DOI: 10.1186/1471-2164-13-71] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 02/14/2012] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND An array of experimental models have been developed in the small model organisms C. elegans, S. cerevisiae and D. melanogaster for the study of various neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and expanded polyglutamine diseases as exemplified by Huntington's disease (HD) and related ataxias. Genetic approaches to determine the nature of regulators of the disease phenotypes have ranged from small scale to essentially whole genome screens. The published data covers distinct models in all three organisms and one important question is the extent to which shared genetic factors can be uncovered that affect several or all disease models. Surprisingly it has appeared that there may be relatively little overlap and that many of the regulators may be organism or disease-specific. There is, however, a need for a fully integrated analysis of the available genetic data based on careful comparison of orthologues across the species to determine the real extent of overlap. RESULTS We carried out an integrated analysis using C. elegans as the baseline model organism since this is the most widely studied in this context. Combination of data from 28 published studies using small to large scale screens in all three small model organisms gave a total of 950 identifications of genetic regulators. Of these 624 were separate genes with orthologues in C. elegans. In addition, 34 of these genes, which all had human orthologues, were found to overlap across studies. Of the common genetic regulators some such as chaperones, ubiquitin-related enzymes (including the E3 ligase CHIP which directly links the two pathways) and histone deacetylases were involved in expected pathways whereas others such as the peroxisomal acyl CoA-oxidase suggest novel targets for neurodegenerative disease therapy CONCLUSIONS We identified a significant number of overlapping regulators of neurodegenerative disease models. Since the diseases have, as an underlying feature, protein aggregation phenotypes it was not surprising that some of the overlapping genes encode proteins involved in protein folding and protein degradation. Interestingly, however, some of the overlapping genes encode proteins that have not previously featured in targeted studies of neurodegeneration and this information will form a useful resource to be exploited in further studies of potential drug-targets.
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Affiliation(s)
- Xi Chen
- Department of Cellular and Molecular Physiology, Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
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Verma A, Sengupta S, Lakhotia SC. DNApol-ϵ gene is indispensable for the survival and growth of Drosophila melanogaster. Genesis 2011; 50:86-101. [PMID: 21898761 DOI: 10.1002/dvg.20791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/12/2011] [Accepted: 08/14/2011] [Indexed: 11/08/2022]
Abstract
Based on deletion and complementation mapping and DNA sequencing, a new recessive fully penetrant mutation (DNApol-ϵpl10R), causing prolonged larval life and larval/early pupal lethality, is identified as the first mutant allele of the DNApol-ϵ (CG6768) gene of Drosophila melanogaster. A same-sense base pair substitution in exon 1 of the DNApol-ϵ gene is associated with retention of the first intron and significant reduction in DNApol-ϵ transcripts in DNApol-ϵpl10R homozygotes. Homozygous mutant larvae show small imaginal discs with fewer cells and reduced polyteny in salivary glands, presumably because of the compromised DNA polymerase function following exhaustion of the maternal contribution. Extremely small and rare DNApol-ϵpl10R homozygous somatic clones in DNApol-ϵpl10R/+imaginal discs confirm their poor mitotic activity. The DNApol-ϵpl10R homozygotes, like those expressing DNApol-ϵ-RNAi transgene, show high sensitivity to DNA damaging agents. The first mutant allele of the DNApol-ϵ gene will facilitate functional characterization of this enzyme in the genetically tractable Drosophila model.
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Affiliation(s)
- Akanksha Verma
- Department of Zoology, Cytogenetics Laboratory, Banaras Hindu University, Varanasi, India
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