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Godfrey RK, Alsop E, Bjork RT, Chauhan BS, Ruvalcaba HC, Antone J, Gittings LM, Michael AF, Williams C, Hala'ufia G, Blythe AD, Hall M, Sattler R, Van Keuren-Jensen K, Zarnescu DC. Modelling TDP-43 proteinopathy in Drosophila uncovers shared and neuron-specific targets across ALS and FTD relevant circuits. Acta Neuropathol Commun 2023; 11:168. [PMID: 37864255 PMCID: PMC10588218 DOI: 10.1186/s40478-023-01656-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/19/2023] [Indexed: 10/22/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) comprise a spectrum of neurodegenerative diseases linked to TDP-43 proteinopathy, which at the cellular level, is characterized by loss of nuclear TDP-43 and accumulation of cytoplasmic TDP-43 inclusions that ultimately cause RNA processing defects including dysregulation of splicing, mRNA transport and translation. Complementing our previous work in motor neurons, here we report a novel model of TDP-43 proteinopathy based on overexpression of TDP-43 in a subset of Drosophila Kenyon cells of the mushroom body (MB), a circuit with structural characteristics reminiscent of vertebrate cortical networks. This model recapitulates several aspects of dementia-relevant pathological features including age-dependent neuronal loss, nuclear depletion and cytoplasmic accumulation of TDP-43, and behavioral deficits in working memory and sleep that occur prior to axonal degeneration. RNA immunoprecipitations identify several candidate mRNA targets of TDP-43 in MBs, some of which are unique to the MB circuit and others that are shared with motor neurons. Among the latter is the glypican Dally-like-protein (Dlp), which exhibits significant TDP-43 associated reduction in expression during aging. Using genetic interactions we show that overexpression of Dlp in MBs mitigates TDP-43 dependent working memory deficits, conistent with Dlp acting as a mediator of TDP-43 toxicity. Substantiating our findings in the fly model, we find that the expression of GPC6 mRNA, a human ortholog of dlp, is specifically altered in neurons exhibiting the molecular signature of TDP-43 pathology in FTD patient brains. These findings suggest that circuit-specific Drosophila models provide a platform for uncovering shared or disease-specific molecular mechanisms and vulnerabilities across the spectrum of TDP-43 proteinopathies.
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Affiliation(s)
- R Keating Godfrey
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA.
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, 3215 Hull Road, Gainesville, FL, 32611, USA.
| | - Eric Alsop
- Translational Genomics Research Institute, 445 N 5th St., Phoenix, AZ, 85004, USA
| | - Reed T Bjork
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Brijesh S Chauhan
- Cellular and Molecular Physiology, Penn State College of Medicine, 500 University Drive Crescent Building C4605, Hershey, PA, 17033, USA
| | - Hillary C Ruvalcaba
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Jerry Antone
- Translational Genomics Research Institute, 445 N 5th St., Phoenix, AZ, 85004, USA
| | - Lauren M Gittings
- Department of Translational Neuroscience, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA
| | - Allison F Michael
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Christi Williams
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Grace Hala'ufia
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Alexander D Blythe
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA
| | - Megan Hall
- Translational Genomics Research Institute, 445 N 5th St., Phoenix, AZ, 85004, USA
| | - Rita Sattler
- Department of Translational Neuroscience, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA
| | | | - Daniela C Zarnescu
- Department of Molecular and Cellular Biology, Life Sciences South, University of Arizona, 1007 E. Lowell St., Tucson, AZ, 85721, USA.
- Cellular and Molecular Physiology, Penn State College of Medicine, 500 University Drive Crescent Building C4605, Hershey, PA, 17033, USA.
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2
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Yusuff T, Chang YC, Sang TK, Jackson GR, Chatterjee S. Codon-optimized TDP-43 mediates neurodegeneration in a Drosophila model of ALS/FTLD. Front Genet 2023; 14:881638. [PMID: 36968586 PMCID: PMC10034021 DOI: 10.3389/fgene.2023.881638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 02/13/2023] [Indexed: 03/11/2023] Open
Abstract
Transactive response DNA binding protein-43 (TDP-43) is known to mediate neurodegeneration associated with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). The exact mechanism by which TDP-43 exerts toxicity in the brains, spinal cord, and lower motor neurons of affected patients remains unclear. In a novel Drosophila melanogaster model, we report gain-of-function phenotypes due to misexpression of insect codon-optimized version of human wild-type TDP-43 (CO-TDP-43) using both the binary GAL4/UAS system and direct promoter fusion constructs. The CO-TDP-43 model showed robust tissue specific phenotypes in the adult eye, wing, and bristles in the notum. Compared to non-codon optimized transgenic flies, the CO-TDP-43 flies produced increased amount of high molecular weight protein, exhibited pathogenic phenotypes, and showed cytoplasmic aggregation with both nuclear and cytoplasmic expression of TDP-43. Further characterization of the adult retina showed a disruption in the morphology and function of the photoreceptor neurons with the presence of acidic vacuoles that are characteristic of autophagy. Based on our observations, we propose that TDP-43 has the propensity to form toxic protein aggregates via a gain-of-function mechanism, and such toxic overload leads to activation of protein degradation pathways such as autophagy. The novel codon optimized TDP-43 model is an excellent resource that could be used in genetic screens to identify and better understand the exact disease mechanism of TDP-43 proteinopathies and find potential therapeutic targets.
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Affiliation(s)
- Tanzeen Yusuff
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- *Correspondence: Tanzeen Yusuff, ; Shreyasi Chatterjee,
| | - Ya-Chu Chang
- Department of Life Science, Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
| | - Tzu-Kang Sang
- Department of Life Science, Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
| | - George R. Jackson
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Department of Neurology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Department of Neurology, Baylor College of Medicine, Houston, TX, United States
- National Parkinson’s Disease Research Education and Clinical Center, Michael E. DeBakey VA Medical Center, Houston, TX, United States
| | - Shreyasi Chatterjee
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Department of Neurology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
- Department of Biochemistry, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
- *Correspondence: Tanzeen Yusuff, ; Shreyasi Chatterjee,
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3
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Liao YZ, Ma J, Dou JZ. The Role of TDP-43 in Neurodegenerative Disease. Mol Neurobiol 2022; 59:4223-4241. [DOI: 10.1007/s12035-022-02847-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/23/2022] [Indexed: 12/14/2022]
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The N Termini of TAR DNA-Binding Protein 43 (TDP43) C-Terminal Fragments Influence Degradation, Aggregation Propensity, and Morphology. Mol Cell Biol 2018; 38:MCB.00243-18. [PMID: 29987190 PMCID: PMC6146831 DOI: 10.1128/mcb.00243-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/03/2018] [Indexed: 02/08/2023] Open
Abstract
Fragments of the TAR DNA-binding protein 43 (TDP43) are major components of intracellular aggregates associated with amyotrophic lateral sclerosis and frontotemporal dementia. A variety of C-terminal fragments (CTFs) exist, with distinct N termini; however, little is known regarding their differences in metabolism and aggregation dynamics. Fragments of the TAR DNA-binding protein 43 (TDP43) are major components of intracellular aggregates associated with amyotrophic lateral sclerosis and frontotemporal dementia. A variety of C-terminal fragments (CTFs) exist, with distinct N termini; however, little is known regarding their differences in metabolism and aggregation dynamics. Previously, we found that specific CTFs accumulate in the absence of the Arg/N-end rule pathway of the ubiquitin proteasome system (UPS) and that their degradation requires arginyl-tRNA protein transferase 1 (ATE1). Here, we examined two specific CTFs of TDP43 (TDP43219 and TDP43247), which are ∼85% identical and differ at their N termini by 28 amino acids. We found that TDP43247 is degraded primarily by the Arg/N-end rule pathway, whereas degradation of TDP43219 continues in the absence of ATE1. These fragments also differ in their aggregation propensities and form morphologically distinct aggregates. This work reveals that the N termini of otherwise similar CTFs have profound effects on fragment behavior and may influence clinical outcomes in neurodegeneration associated with aggregation.
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Jantrapirom S, Lo Piccolo L, Yoshida H, Yamaguchi M. Depletion of Ubiquilin induces an augmentation in soluble ubiquitinated Drosophila TDP-43 to drive neurotoxicity in the fly. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3038-3049. [PMID: 29936333 DOI: 10.1016/j.bbadis.2018.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/16/2018] [Accepted: 06/20/2018] [Indexed: 12/13/2022]
Abstract
The proteostasis machinery has critical functions in metabolically active cells such as neurons. Ubiquilins (UBQLNs) may decide the fate of proteins, with its ability to bind and deliver ubiquitinated misfolded or no longer functionally required proteins to the ubiquitin-proteasome system (UPS) and/or autophagy. Missense mutations in UBQLN2 have been linked to X-linked dominant amyotrophic lateral sclerosis with frontotemporal dementia (ALS-FTD). Although aggregation-prone TAR DNA-binding protein 43 (TDP-43) has been recognized as a major component of the ubiquitin pathology, the mechanisms by which UBQLN involves in TDP-43 proteinopathy have not yet been elucidated in detail. We previously characterized a new Drosophila Ubiquilin (dUbqn) knockdown model that produces learning/memory and locomotive deficits during the proteostasis impairment. In the present study, we demonstrated that the depletion of dUbqn markedly affected the expression and sub-cellular localization of Drosophila TDP-43 (TBPH), resulting in a cytoplasmic ubiquitin-positive (Ub+) TBPH pathology. Although we found that the knockdown of dUbqn widely altered and affected the turnover of a large number of proteins, we herein showed that an augmented soluble cytoplasmic Ub+-TBPH is as a crucial source of neurotoxicity following the depletion of dUbqn. We demonstrated that dUbqn knockdown-related neurotoxicity may be rescued by either restoring the proteostasis machinery or reducing the expression of TBPH. These novel results extend our knowledge on the UBQLN loss-of-function pathomechanism and may contribute to the identification of new therapeutics for ALS-FTD and aging-related diseases.
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Affiliation(s)
- Salinee Jantrapirom
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Luca Lo Piccolo
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; Department of Neurotherapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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6
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Langellotti S, Romano G, Feiguin F, Baralle FE, Romano M. RhoGAPp190: A potential player in tbph-mediated neurodegeneration in Drosophila. PLoS One 2018; 13:e0195845. [PMID: 29652933 PMCID: PMC5898758 DOI: 10.1371/journal.pone.0195845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 04/01/2018] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is an ubiquitous and highly conserved ribonucleoprotein involved in several cellular processes including pre-mRNA splicing, transcription, mRNA stability and transport. Notwithstanding the evidence of TDP-43 involvement in the pathogenesis of different neurodegenerative disorders (i.e. ALS and FTLD), the underlying mechanisms are still unclear. Given the high degree of functional similarity between the human and fly orthologs of TDP-43, Drosophila melanogaster is a simple and useful model to study the pathophysiological role of this protein in vivo. It has been demonstrated that the depletion of the TDP-43 fly ortholog (tbph) induces deficient locomotive behaviors and reduces life span and anatomical defects at the neuromuscular junction. In this study, using the known binding specificity of TDP-43/tbph for (UG) repeated sequences, we performed a bioinformatic screening for fly genes with at least 6 (TG) repeats in a row within the 3'-UTR regions in order to identify the genes that might be regulated by this factor. Among these genes, we were able to identify RhoGAPp190 as a potential target of the tbph-mediated neurodegeneration. RhoGAPp190 is a negative regulator of Drosophila RhoA, a GTPase protein implicated in the fine modulation of critical cellular processes including axon branch stability and motor axon defasciculation at muscle level and cognitive processes. We were able to demonstrate that the RhoGAPp190 expression is upregulated in a tbph-null fly model, providing evidence that this deregulation is associated to tbph silencing. Our results introduce RhoGAPp190 as a novel potential mediator in the complex scenario of events resulting from in vivo tbph loss-of-function.
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Affiliation(s)
- Simona Langellotti
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Giulia Romano
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Fabian Feiguin
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Trieste, Italy
- * E-mail:
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Appocher C, Mohagheghi F, Cappelli S, Stuani C, Romano M, Feiguin F, Buratti E. Major hnRNP proteins act as general TDP-43 functional modifiers both in Drosophila and human neuronal cells. Nucleic Acids Res 2017; 45:8026-8045. [PMID: 28575377 PMCID: PMC5570092 DOI: 10.1093/nar/gkx477] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 05/16/2017] [Indexed: 12/13/2022] Open
Abstract
Nuclear factor TDP-43 is known to play an important role in several neurodegenerative pathologies. In general, TDP-43 is an abundant protein within the eukaryotic nucleus that binds to many coding and non-coding RNAs and influence their processing. Using Drosophila, we have performed a functional screening to establish the ability of major hnRNP proteins to affect TDP-43 overexpression/depletion phenotypes. Interestingly, we observed that lowering hnRNP and TDP-43 expression has a generally harmful effect on flies locomotor abilities. In parallel, our study has also identified a distinct set of hnRNPs that is capable of powerfully rescuing TDP-43 toxicity in the fly eye (Hrb27c, CG42458, Glo and Syp). Most importantly, removing the human orthologs of Hrb27c (DAZAP1) in human neuronal cell lines can correct several pre-mRNA splicing events altered by TDP-43 depletion. Moreover, using RNA sequencing analysis we show that DAZAP1 and TDP-43 can co-regulate an extensive number of biological processes and molecular functions potentially important for the neuron/motor neuron pathophysiology. Our results suggest that changes in hnRNP expression levels can significantly modulate TDP-43 functions and affect pathological outcomes.
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Affiliation(s)
- Chiara Appocher
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Fatemeh Mohagheghi
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Sara Cappelli
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Cristiana Stuani
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Via A. Valerio 28, 34127 Trieste, Italy
| | - Fabian Feiguin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
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Krug L, Chatterjee N, Borges-Monroy R, Hearn S, Liao WW, Morrill K, Prazak L, Rozhkov N, Theodorou D, Hammell M, Dubnau J. Retrotransposon activation contributes to neurodegeneration in a Drosophila TDP-43 model of ALS. PLoS Genet 2017; 13:e1006635. [PMID: 28301478 PMCID: PMC5354250 DOI: 10.1371/journal.pgen.1006635] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 02/14/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are two incurable neurodegenerative disorders that exist on a symptomological spectrum and share both genetic underpinnings and pathophysiological hallmarks. Functional abnormality of TAR DNA-binding protein 43 (TDP-43), an aggregation-prone RNA and DNA binding protein, is observed in the vast majority of both familial and sporadic ALS cases and in ~40% of FTLD cases, but the cascade of events leading to cell death are not understood. We have expressed human TDP-43 (hTDP-43) in Drosophila neurons and glia, a model that recapitulates many of the characteristics of TDP-43-linked human disease including protein aggregation pathology, locomotor impairment, and premature death. We report that such expression of hTDP-43 impairs small interfering RNA (siRNA) silencing, which is the major post-transcriptional mechanism of retrotransposable element (RTE) control in somatic tissue. This is accompanied by de-repression of a panel of both LINE and LTR families of RTEs, with somewhat different elements being active in response to hTDP-43 expression in glia versus neurons. hTDP-43 expression in glia causes an early and severe loss of control of a specific RTE, the endogenous retrovirus (ERV) gypsy. We demonstrate that gypsy causes the degenerative phenotypes in these flies because we are able to rescue the toxicity of glial hTDP-43 either by genetically blocking expression of this RTE or by pharmacologically inhibiting RTE reverse transcriptase activity. Moreover, we provide evidence that activation of DNA damage-mediated programmed cell death underlies both neuronal and glial hTDP-43 toxicity, consistent with RTE-mediated effects in both cell types. Our findings suggest a novel mechanism in which RTE activity contributes to neurodegeneration in TDP-43-mediated diseases such as ALS and FTLD.
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Affiliation(s)
- Lisa Krug
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Nabanita Chatterjee
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | | | - Stephen Hearn
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Wen-Wei Liao
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Kathleen Morrill
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Lisa Prazak
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
- Department of Biology, Farmingdale State College, Farmingdale, NY United States of America
| | - Nikolay Rozhkov
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Delphine Theodorou
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Molly Hammell
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
| | - Josh Dubnau
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States of America
- Department of Anesthesiology, Stony Brook School of Medicine, Stony Brook, New York, United States of America
- Department of Neurobiology and Behavior, Stony Brook School of Medicine, Stony Brook, New York, United States of America
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Langellotti S, Romano V, Romano G, Klima R, Feiguin F, Cragnaz L, Romano M, Baralle FE. A novel Drosophila model of TDP-43 proteinopathies: N-terminal sequences combined with the Q/N domain induce protein functional loss and locomotion defects. Dis Model Mech 2016; 9:659-69. [PMID: 27101846 PMCID: PMC4920146 DOI: 10.1242/dmm.023382] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 04/20/2016] [Indexed: 12/12/2022] Open
Abstract
Transactive response DNA-binding protein 43 kDa (TDP-43, also known as TBPH in Drosophila melanogaster and TARDBP in mammals) is the main protein component of the pathological inclusions observed in neurons of patients affected by different neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and fronto-temporal lobar degeneration (FTLD). The number of studies investigating the molecular mechanisms underlying neurodegeneration is constantly growing; however, the role played by TDP-43 in disease onset and progression is still unclear. A fundamental shortcoming that hampers progress is the lack of animal models showing aggregation of TDP-43 without overexpression. In this manuscript, we have extended our cellular model of aggregation to a transgenic Drosophila line. Our fly model is not based on the overexpression of a wild-type TDP-43 transgene. By contrast, we engineered a construct that includes only the specific TDP-43 amino acid sequences necessary to trigger aggregate formation and capable of trapping endogenous Drosophila TDP-43 into a non-functional insoluble form. Importantly, the resulting recombinant product lacks functional RNA recognition motifs (RRMs) and, thus, does not have specific TDP-43-physiological functions (i.e. splicing regulation ability) that might affect the animal phenotype per se. This novel Drosophila model exhibits an evident degenerative phenotype with reduced lifespan and early locomotion defects. Additionally, we show that important proteins involved in neuromuscular junction function, such as syntaxin (SYX), decrease their levels as a consequence of TDP-43 loss of function implying that the degenerative phenotype is a consequence of TDP-43 sequestration into the aggregates. Our data lend further support to the role of TDP-43 loss-of-function in the pathogenesis of neurodegenerative disorders. The novel transgenic Drosophila model presented in this study will help to gain further insight into the molecular mechanisms underlying neurodegeneration and will provide a valuable system to test potential therapeutic agents to counteract disease. Summary: An engineered TDP-43 construct can be used to induce TDP-43 aggregation in Drosophila, providing a model that could be useful for characterization of pathogenetic mechanisms and drug screening.
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Affiliation(s)
- Simona Langellotti
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Valentina Romano
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Giulia Romano
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Raffaella Klima
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Fabian Feiguin
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Lucia Cragnaz
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
| | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Via A. Valerio 28, Trieste 34127, Italy
| | - Francisco E Baralle
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, Trieste I-34149, Italy
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10
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TBPH/TDP-43 modulates translation of Drosophila futsch mRNA through an UG-rich sequence within its 5'UTR. Brain Res 2016; 1647:50-56. [PMID: 26902497 DOI: 10.1016/j.brainres.2016.02.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/05/2016] [Accepted: 02/11/2016] [Indexed: 12/13/2022]
Abstract
Nuclear factor TDP-43 is an evolutionarily conserved multifunctional RNA-binding protein associated with frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). In recent years, Drosophila models of ALS based on TDP-43 knockdown/overexpression have allowed to find several connections with disease. Among these, we have previously described that silencing the expression of its fly ortholog (TBPH) can alter the expression of the neuronal microtubule-associated protein Futsch leading to alterations of neuromuscular junction (NMJ) organization. In particular, TBPH knocked out flies displayed a significant reduction of Futsch protein levels, although minimal variation in the futsch mRNA content was observed. These conclusions were recently validated in an independent study. Together, these observations strongly support the hypothesis that TBPH might regulate the translation of futsch mRNA. However, the mechanism of TBPH interference in futsch mRNA translation is still unknown. In this work, we use EMSA experiments coupled with RNA-protein co-immunprecipitations and luciferase assays to show that TBPH interacts with a stretch of UG within the 5'UTR of futsch mRNA and translation is positively modulated by this binding. Most importantly, this function is also conserved in human TDP-43. This result can therefore represent the first step in elucidating the relationship between TDP-43, protein translation, and eventual disease onset or progression. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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11
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Buratti E. Functional Significance of TDP-43 Mutations in Disease. ADVANCES IN GENETICS 2015; 91:1-53. [DOI: 10.1016/bs.adgen.2015.07.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Zhan L, Xie Q, Tibbetts RS. Opposing roles of p38 and JNK in a Drosophila model of TDP-43 proteinopathy reveal oxidative stress and innate immunity as pathogenic components of neurodegeneration. Hum Mol Genet 2014; 24:757-72. [PMID: 25281658 DOI: 10.1093/hmg/ddu493] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pathological aggregation and mutation of the 43-kDa TAR DNA-binding protein (TDP-43) are strongly implicated in the pathogenesis amyotrophic lateral sclerosis and frontotemporal lobar degeneration. TDP-43 neurotoxicity has been extensively modeled in mice, zebrafish, Caenorhabditis elegans and Drosophila, where selective expression of TDP-43 in motoneurons led to paralysis and premature lethality. Through a genetic screen aimed to identify genetic modifiers of TDP-43, we found that the Drosophila dual leucine kinase Wallenda (Wnd) and its downstream kinases JNK and p38 influenced TDP-43 neurotoxicity. Reducing Wnd gene dosage or overexpressing its antagonist highwire partially rescued TDP-43-associated premature lethality. Downstream of Wnd, the JNK and p38 kinases played opposing roles in TDP-43-associated neurodegeneration. LOF alleles of the p38b gene as well as p38 inhibitors diminished TDP-43-associated premature lethality, whereas p38b GOF caused phenotypic worsening. In stark contrast, disruptive alleles of Basket (Bsk), the Drosophila homologue of JNK, exacerbated longevity shortening, whereas overexpression of Bsk extended lifespan. Among possible mechanisms, we found motoneuron-directed expression of TDP-43 elicited oxidative stress and innate immune gene activation that were exacerbated by p38 GOF and Bsk LOF, respectively. A key pathologic role for innate immunity in TDP-43-associated neurodegeneration was further supported by the finding that genetic suppression of the Toll/Dif and Imd/Relish inflammatory pathways dramatically extended lifespan of TDP-43 transgenic flies. We propose that oxidative stress and neuroinflammation are intrinsic components of TDP-43-associated neurodegeneration and that the balance between cytoprotective JNK and cytotoxic p38 signaling dictates phenotypic outcome to TDP-43 expression in Drosophila.
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Affiliation(s)
- Lihong Zhan
- Department of Human Oncology, Program in Molecular and Cellular Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Qijing Xie
- Department of Human Oncology, Program in Molecular and Cellular Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Randal S Tibbetts
- Department of Human Oncology, Program in Molecular and Cellular Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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13
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Zhu L, Xu M, Yang M, Yang Y, Li Y, Deng J, Ruan L, Liu J, Du S, Liu X, Feng W, Fushimi K, Bigio EH, Mesulam M, Wang C, Wu JY. An ALS-mutant TDP-43 neurotoxic peptide adopts an anti-parallel β-structure and induces TDP-43 redistribution. Hum Mol Genet 2014; 23:6863-77. [PMID: 25113748 DOI: 10.1093/hmg/ddu409] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
TDP-43 proteinopathies are clinically and genetically heterogeneous diseases that had been considered distinct from classical amyloid diseases. Here, we provide evidence for the structural similarity between TDP-43 peptides and other amyloid proteins. Atomic force microscopy and electron microscopy examination of peptides spanning a previously defined amyloidogenic fragment revealed a minimal core region that forms amyloid fibrils similar to the TDP-43 fibrils detected in FTLD-TDP brain tissues. An ALS-mutant A315E amyloidogenic TDP-43 peptide is capable of cross-seeding other TDP-43 peptides and an amyloid-β peptide. Sequential Nuclear Overhauser Effects and double-quantum-filtered correlation spectroscopy in nuclear magnetic resonance (NMR) analyses of the A315E-mutant TDP-43 peptide indicate that it adopts an anti-parallel β conformation. When added to cell cultures, the amyloidogenic TDP-43 peptides induce TDP-43 redistribution from the nucleus to the cytoplasm. Neuronal cultures in compartmentalized microfluidic-chambers demonstrate that the TDP-43 peptides can be taken up by axons and induce axonotoxicity and neuronal death, thus recapitulating key neuropathological features of TDP-43 proteinopathies. Importantly, a single amino acid change in the amyloidogenic TDP-43 peptide that disrupts fibril formation also eliminates neurotoxicity, supporting that amyloidogenesis is critical for TDP-43 neurotoxicity.
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Affiliation(s)
- Li Zhu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Meng Xu
- National Center for Nanoscience and Technology, Beijing, China Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China and
| | - Mengxue Yang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China University of the Chinese Academy of Sciences, Beijing, China Department of Neurology, Center for Genetic Medicine, Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Yanlian Yang
- National Center for Nanoscience and Technology, Beijing, China
| | - Yang Li
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China Department of Neurology, Center for Genetic Medicine, Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Jianwen Deng
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China University of the Chinese Academy of Sciences, Beijing, China
| | - Linhao Ruan
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China University of the Chinese Academy of Sciences, Beijing, China
| | - Jianghong Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Sidan Du
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China Department of Neurology, Center for Genetic Medicine, Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Xuehui Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Feng
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kazuo Fushimi
- Department of Neurology, Center for Genetic Medicine, Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Eileen H Bigio
- The Cognitive Neurology & Alzheimer's Disease Center, Northwestern University Feinberg School of Medicine, 303 E. Chicago, Chicago, IL 60611, USA
| | - Marsel Mesulam
- The Cognitive Neurology & Alzheimer's Disease Center, Northwestern University Feinberg School of Medicine, 303 E. Chicago, Chicago, IL 60611, USA
| | - Chen Wang
- National Center for Nanoscience and Technology, Beijing, China
| | - Jane Y Wu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China Department of Neurology, Center for Genetic Medicine, Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, USA
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14
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Romano G, Klima R, Buratti E, Verstreken P, Baralle FE, Feiguin F. Chronological requirements of TDP-43 function in synaptic organization and locomotive control. Neurobiol Dis 2014; 71:95-109. [PMID: 25088713 DOI: 10.1016/j.nbd.2014.07.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/12/2014] [Accepted: 07/23/2014] [Indexed: 12/12/2022] Open
Abstract
Alterations in TDP-43 are commonly found in patients suffering from amyotrophic lateral sclerosis (ALS) and the genetic suppression of the conserved homologue in Drosophila (TBPH) provokes alterations in the functional organization of motoneuron synaptic terminals, resulting in locomotive defects and reduced life span. To gain more insight into this pathological process, it is of fundamental importance to establish when during the fly life cycle the lack of TBPH affects motoneuron activity and whether this is a reversible phenomenon. To achieve this, we conditionally expressed the endogenous protein in TBPH minus Drosophila neurons and found that TBPH is a short lived protein permanently required for Drosophila motility and synaptic assembly through the direct modulation of vesicular proteins, such as Syntaxin 1A, indicating that synaptic transmission defects are early pathological consequences of TBPH dysfunction in vivo. Importantly, TBPH late induction is able to recover synaptogenesis and locomotion in adult flies revealing an unexpected late-stage functional and structural neuronal plasticity. These observations suggest that late therapeutic approaches based on TDP-43 functionality may also be successful for the human pathology.
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Affiliation(s)
- Giulia Romano
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Raffaella Klima
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | | | - Francisco E Baralle
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
| | - Fabian Feiguin
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
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15
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He F, Krans A, Freibaum BD, Taylor JP, Todd PK. TDP-43 suppresses CGG repeat-induced neurotoxicity through interactions with HnRNP A2/B1. Hum Mol Genet 2014; 23:5036-51. [PMID: 24920338 DOI: 10.1093/hmg/ddu216] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Nucleotide repeat expansions can elicit neurodegeneration as RNA by sequestering specific RNA-binding proteins, preventing them from performing their normal functions. Conversely, mutations in RNA-binding proteins can trigger neurodegeneration at least partly by altering RNA metabolism. In Fragile X-associated tremor/ataxia syndrome (FXTAS), a CGG repeat expansion in the 5'UTR of the fragile X gene (FMR1) leads to progressive neurodegeneration in patients and CGG repeats in isolation elicit toxicity in Drosophila and other animal models. Here, we identify the amyotrophic lateral sclerosis (ALS)-associated RNA-binding protein TAR DNA-binding protein (TDP-43) as a suppressor of CGG repeat-induced toxicity in a Drosophila model of FXTAS. The rescue appears specific to TDP-43, as co-expression of another ALS-associated RNA-binding protein, FUS, exacerbates the toxic effects of CGG repeats. Suppression of CGG RNA toxicity was abrogated by disease-associated mutations in TDP-43. TDP-43 does not co-localize with CGG RNA foci and its ability to bind RNA is not required for rescue. TDP-43-dependent rescue does, however, require fly hnRNP A2/B1 homologues Hrb87F and Hrb98DE. Deletions in the C-terminal domain of TDP-43 that preclude interactions with hnRNP A2/B1 abolish TDP-43-dependent rescue of CGG repeat toxicity. In contrast, suppression of CGG repeat toxicity by hnRNP A2/B1 is not affected by RNAi-mediated knockdown of the fly TDP-43 orthologue, TBPH. Lastly, TDP-43 suppresses CGG repeat-triggered mis-splicing of an hnRNP A2/B1-targeted transcript. These data support a model in which TDP-43 suppresses CGG-mediated toxicity through interactions with hnRNP A2/B1 and suggest a convergence of pathogenic cascades between repeat expansion disorders and RNA-binding proteins implicated in neurodegenerative disease.
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Affiliation(s)
- Fang He
- Department of Neurology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109, USA
| | - Amy Krans
- Department of Neurology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109, USA
| | - Brian D Freibaum
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN 38105, USA and
| | - J Paul Taylor
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN 38105, USA and
| | - Peter K Todd
- Department of Neurology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109, USA, VA Medical Center, Ann Arbor, MI 48105, USA
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16
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Salado IG, Redondo M, Bello ML, Perez C, Liachko NF, Kraemer BC, Miguel L, Lecourtois M, Gil C, Martinez A, Perez DI. Protein kinase CK-1 inhibitors as new potential drugs for amyotrophic lateral sclerosis. J Med Chem 2014; 57:2755-72. [PMID: 24592867 PMCID: PMC3969104 DOI: 10.1021/jm500065f] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease where motor neurons in cortex, brain stem, and spinal cord die progressively, resulting in muscle wasting, paralysis, and death. Currently, effective therapies for ALS are lacking; however, identification of pathological TAR DNA-binding protein 43 (TDP-43) as the hallmark lesion in sporadic ALS suggests new therapeutic targets for pharmacological intervention. Pathological TDP-43 phosphorylation appears to drive the onset and progression of ALS and may result from upregulation of the protein kinase CK-1 in affected neurons, resulting in postranslational TDP-43 modification. Consequently, brain penetrant specific CK-1 inhibitors may provide a new therapeutic strategy for treating ALS and other TDP-43 proteinopathies. Using a chemical genetic approach, we report the discovery and further optimization of a number of potent CK-1δ inhibitors. Moreover, these small heterocyclic molecules are able to prevent TDP-43 phosphorylation in cell cultures, to increase Drosophila lifespan by reduction of TDP-43 neurotoxicity, and are predicted to cross the blood-brain barrier. Thus, N-(benzothiazolyl)-2-phenyl-acetamides are valuable drug candidates for further studies and may be a new therapeutic approach for ALS and others pathologies in which TDP-43 is involved.
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Affiliation(s)
- Irene G Salado
- Instituto de Química Médica, CSIC , Juan de la Cierva 3, 28006 Madrid, Spain
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17
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Romano M, Buratti E, Romano G, Klima R, Del Bel Belluz L, Stuani C, Baralle F, Feiguin F. Evolutionarily conserved heterogeneous nuclear ribonucleoprotein (hnRNP) A/B proteins functionally interact with human and Drosophila TAR DNA-binding protein 43 (TDP-43). J Biol Chem 2014; 289:7121-7130. [PMID: 24492607 DOI: 10.1074/jbc.m114.548859] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human TDP-43 represents the main component of neuronal inclusions found in patients with neurodegenerative diseases, especially frontotemporal lobar degeneration and amyotrophic lateral sclerosis. In vitro and in vivo studies have shown that the TAR DNA-binding protein 43 (TDP-43) Drosophila ortholog (TBPH) can biochemically and functionally overlap the properties of the human factor. The recent direct implication of the human heterogeneous nuclear ribonucleoproteins (hnRNPs) A2B1 and A1, known TDP-43 partners, in the pathogenesis of multisystem proteinopathy and amyotrophic lateral sclerosis supports the hypothesis that the physical and functional interplay between TDP-43 and hnRNP A/B orthologs might play a crucial role in the pathogenesis of neurodegenerative diseases. To test this hypothesis and further validate the fly system as a useful model to study this type of diseases, we have now characterized human TDP-43 and Drosophila TBPH similarity in terms of protein-protein interaction pathways. In this work we show that TDP-43 and TBPH share the ability to associate in vitro with Hrp38/Hrb98DE/CG9983, the fruit fly ortholog of the human hnRNP A1/A2 factors. Interestingly, the protein regions of TDP-43 and Hrp38 responsible for reciprocal interactions are conserved through evolution. Functionally, experiments in HeLa cells demonstrate that TDP-43 is necessary for the inhibitory activity of Hrp38 on splicing. Finally, Drosophila in vivo studies show that Hrp38 deficiency produces locomotive defects and life span shortening in TDP-43 with and without animals. These results suggest that hnRNP protein levels can play a modulatory role on TDP-43 functions.
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Affiliation(s)
- Maurizio Romano
- Department of Life Sciences, University of Trieste, Via A. Valerio 28, 34127 Trieste, Italy.
| | - Emanuele Buratti
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | - Giulia Romano
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | - Raffaella Klima
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | - Lisa Del Bel Belluz
- Department of Life Sciences, University of Trieste, Via A. Valerio 28, 34127 Trieste, Italy
| | - Cristiana Stuani
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | - Francisco Baralle
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | - Fabian Feiguin
- International Centre for Genetic Engineering an Biotechnology, Padriciano 99, I-34149 Trieste, Italy
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18
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Abstract
Dysfunctions at the level of RNA processing have recently been shown to play a fundamental role in the pathogenesis of many neurodegenerative diseases. Several proteins responsible for these dysfunctions (TDP-43, FUS/TLS, and hnRNP A/Bs) belong to the nuclear class of heterogeneous ribonucleoproteins (hnRNPs) that predominantly function as general regulators of both coding and noncoding RNA metabolism. The discovery of the importance of these factors in mediating neuronal death has represented a major paradigmatic shift in our understanding of neurodegenerative processes. As a result, these discoveries have also opened the way toward novel biomolecular screening approaches in our search for therapeutic options. One of the major hurdles in this search is represented by the correct identification of the most promising targets to be prioritized. These may include aberrant aggregation processes, protein-protein interactions, RNA-protein interactions, or specific cellular pathways altered by disease. In this review, we discuss these four major options together with their various advantages and drawbacks.
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Affiliation(s)
- Maurizio Romano
- 1Department of Life Sciences, University of Trieste, Trieste, Italy
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19
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Lattante S, Rouleau GA, Kabashi E. TARDBPandFUSMutations Associated with Amyotrophic Lateral Sclerosis: Summary and Update. Hum Mutat 2013; 34:812-26. [DOI: 10.1002/humu.22319] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/28/2013] [Indexed: 12/11/2022]
Affiliation(s)
- Serena Lattante
- Institut du Cerveau et de la Moelle épinière; Centre de Recherche, CHU Pitié-Salpétrière, Inserm, UMR_S975, CRICM, F-75013; UPMC Univ Paris 06, UMR_S975, F-75013; CNRS UMR 7225; F-75013; Paris; France
| | - Guy A. Rouleau
- Montreal Neurological Institute; Department of Neurology and Neurosurgery, McGill University; Montreal; Canada
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