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Charif SE, Luchelli L, Vila A, Blaustein M, Igaz LM. Cytoplasmic Expression of the ALS/FTD-Related Protein TDP-43 Decreases Global Translation Both in vitro and in vivo. Front Cell Neurosci 2020; 14:594561. [PMID: 33363456 PMCID: PMC7752804 DOI: 10.3389/fncel.2020.594561] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/18/2020] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is a major component of cytoplasmic inclusions observed in neurodegenerative diseases like frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). To further understand the role of TDP-43 in mRNA/protein metabolism and proteostasis, we used a combined approach with cellular and animal models overexpressing a cytoplasmic form of human TDP-43 (TDP-43-ΔNLS), recapitulating ALS/FTD features. We applied in HEK293 cells a method for labeling de novo translation, surface sensing of translation (SUnSET), based on puromycin (PURO) incorporation. While control cells displayed robust puromycilation, TDP-43-ΔNLS transfected cells exhibited reduced ongoing protein synthesis. Next, by using a transgenic mouse overexpressing cytoplasmic TDP-43 in the forebrain (TDP-43-ΔNLS mice) we assessed whether cytoplasmic TDP-43 regulates global translation in vivo. Polysome profiling of brain cortices from transgenic mice showed a shift toward non-polysomal fractions as compared to wild-type littermates, indicating a decrease in global translation. Lastly, cellular level translational assessment by SUNSET was performed in TDP-43-ΔNLS mice brain slices. Control mice slices incubated with PURO exhibited robust cytoplasmic PURO signal in layer 5 neurons from motor cortex, and normal nuclear TDP-43 staining. Neurons in TDP-43-ΔNLS mice slices incubated with PURO exhibited high cytoplasmic expression of TDP-43 and reduced puromycilation respect to control mice. These in vitro and in vivo results indicate that cytoplasmic TDP-43 decreases global translation and potentially cause functional/cytotoxic effects as observed in ALS/FTD. Our study provide in vivo evidence (by two independent and complementary methods) for a role of mislocalized TDP-43 in the regulation of global mRNA translation, with implications for TDP-43 proteinopathies.
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Affiliation(s)
- Santiago E Charif
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Luciana Luchelli
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Antonella Vila
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Matías Blaustein
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lionel M Igaz
- Instituto de Fisiología y Biofísica "Bernardo Houssay", (IFIBIO-Houssay), Grupo de Neurociencia de Sistemas, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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52
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Patel S, Howard D, Man A, Schwartz D, Jee J, Felsky D, Pausova Z, Paus T, French L. Donor-Specific Transcriptomic Analysis of Alzheimer's Disease-Associated Hypometabolism Highlights a Unique Donor, Ribosomal Proteins and Microglia. eNeuro 2020; 7:ENEURO.0255-20.2020. [PMID: 33234543 PMCID: PMC7772516 DOI: 10.1523/eneuro.0255-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/25/2020] [Accepted: 10/19/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) starts decades before clinical symptoms appear. Low-glucose utilization in regions of the cerebral cortex marks early AD. To identify these regions, we conducted a voxel-wise meta-analysis of previous studies conducted with positron emission tomography that compared AD patients with healthy controls. The resulting map marks hypometabolism in the posterior cingulate, middle frontal, angular gyrus, and middle and inferior temporal regions. Using the Allen Human Brain Atlas, we identified genes that show spatial correlation across the cerebral cortex between their expression and this hypometabolism. Of the six brains in the Atlas, one demonstrated a strong spatial correlation between gene expression and hypometabolism. Previous neuropathological assessment of this brain from a 39-year-old male noted a neurofibrillary tangle in the entorhinal cortex. Using the transcriptomic data, we estimate lower proportions of neurons and more microglia in the hypometabolic regions when comparing this donor's brain with the other five donors. Within this single brain, signal recognition particle (SRP)-dependent cotranslational protein targeting genes, which encode primarily cytosolic ribosome proteins, are highly expressed in the hypometabolic regions. Analyses of human and mouse data show that expression of these genes increases progressively across AD-associated states of microglial activation. In addition, genes involved in cell killing, chronic inflammation, ubiquitination, tRNA aminoacylation, and vacuole sorting are associated with the hypometabolism map. These genes suggest disruption of the protein life cycle and neuroimmune activation. Taken together, our molecular characterization reveals a link to AD-associated hypometabolism that may be relevant to preclinical stages of AD.
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Affiliation(s)
- Sejal Patel
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
| | - Derek Howard
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
| | - Alana Man
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
- Victoria College, University of Toronto, Toronto, Ontario M5S 1K7, Canada
| | - Deborah Schwartz
- Rotman Research Institute, Baycrest Centre for Geriatric Care, University of Toronto, Toronto, Ontario M6A 2E1, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada
| | - Joelle Jee
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
- Faculty of Arts and Science, University of Toronto, Toronto, Ontario M5S 3G3, Canada
| | - Daniel Felsky
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
| | - Zdenka Pausova
- The Hospital for Sick Children, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Tomas Paus
- Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada
- Department of Psychiatry, University of Toronto, Ontario M5S 3G3, Toronto
- Institute for Medical Science, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Leon French
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
- Department of Psychiatry, University of Toronto, Ontario M5S 3G3, Toronto
- Institute for Medical Science, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario M5T 1L8, Canada
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53
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Differential Expression of mRNAs in Peripheral Blood Related to Prodrome and Progression of Alzheimer's Disease. BIOMED RESEARCH INTERNATIONAL 2020; 2020:4505720. [PMID: 33204697 PMCID: PMC7648929 DOI: 10.1155/2020/4505720] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/25/2020] [Accepted: 10/19/2020] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease that affects the quality of life of elderly individuals, while the pathogenesis of AD is still unclear. Based on the bioinformatics analysis of differentially expressed genes (DEGs) in peripheral blood samples, we investigated genes related to mild cognitive impairment (MCI), AD, and late-stage AD that might be used for predicting the conversions. Methods. We obtained the DEGs in MCI, AD, and advanced AD patients from the Gene Expression Omnibus (GEO) database. A Venn diagram was used to identify the intersecting genes. Gene Ontology (GO) and Kyoto Gene and Genomic Encyclopedia (KEGG) were used to analyze the functions and pathways of the intersecting genes. Protein-protein interaction (PPI) networks were constructed to visualize the network of the proteins coded by the related genes. Hub genes were selected based on the PPI network. Results. Bioinformatics analysis indicated that there were 61 DEGs in both the MCI and AD groups and 27 the same DEGs among the three groups. Using GO and KEGG analyses, we found that these genes were related to the function of mitochondria and ribosome. Hub genes were determined by bioinformatics software based on the PPI network. Conclusions. Mitochondrial and ribosomal dysfunction in peripheral blood may be early signs in AD patients and related to the disease progression. The identified hub genes may provide the possibility for predicting AD progression or be the possible targets for treatments.
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54
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Alyenbaawi H, Allison WT, Mok SA. Prion-Like Propagation Mechanisms in Tauopathies and Traumatic Brain Injury: Challenges and Prospects. Biomolecules 2020; 10:E1487. [PMID: 33121065 PMCID: PMC7692808 DOI: 10.3390/biom10111487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/23/2022] Open
Abstract
The accumulation of tau protein in the form of filamentous aggregates is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). These dementias share traumatic brain injury (TBI) as a prominent risk factor. Tau aggregates can transfer between cells and tissues in a "prion-like" manner, where they initiate the templated misfolding of normal tau molecules. This enables the spread of tau pathology to distinct parts of the brain. The evidence that tauopathies spread via prion-like mechanisms is considerable, but work detailing the mechanisms of spread has mostly used in vitro platforms that cannot fully reveal the tissue-level vectors or etiology of progression. We review these issues and then briefly use TBI and CTE as a case study to illustrate aspects of tauopathy that warrant further attention in vivo. These include seizures and sleep/wake disturbances, emphasizing the urgent need for improved animal models. Dissecting these mechanisms of tauopathy progression continues to provide fresh inspiration for the design of diagnostic and therapeutic approaches.
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Affiliation(s)
- Hadeel Alyenbaawi
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Medical Laboratories, Majmaah University, Majmaah 11952, Saudi Arabia
| | - W. Ted Allison
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Sue-Ann Mok
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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55
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Mangleburg CG, Wu T, Yalamanchili HK, Guo C, Hsieh YC, Duong DM, Dammer EB, De Jager PL, Seyfried NT, Liu Z, Shulman JM. Integrated analysis of the aging brain transcriptome and proteome in tauopathy. Mol Neurodegener 2020; 15:56. [PMID: 32993812 PMCID: PMC7526226 DOI: 10.1186/s13024-020-00405-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/18/2020] [Indexed: 01/09/2023] Open
Abstract
Background Tau neurofibrillary tangle pathology characterizes Alzheimer’s disease and other neurodegenerative tauopathies. Brain gene expression profiles can reveal mechanisms; however, few studies have systematically examined both the transcriptome and proteome or differentiated Tau- versus age-dependent changes. Methods Paired, longitudinal RNA-sequencing and mass-spectrometry were performed in a Drosophila model of tauopathy, based on pan-neuronal expression of human wildtype Tau (TauWT) or a mutant form causing frontotemporal dementia (TauR406W). Tau-induced, differentially expressed transcripts and proteins were examined cross-sectionally or using linear regression and adjusting for age. Hierarchical clustering was performed to highlight network perturbations, and we examined overlaps with human brain gene expression profiles in tauopathy. Results TauWT induced 1514 and 213 differentially expressed transcripts and proteins, respectively. TauR406W had a substantially greater impact, causing changes in 5494 transcripts and 697 proteins. There was a ~ 70% overlap between age- and Tau-induced changes and our analyses reveal pervasive bi-directional interactions. Strikingly, 42% of Tau-induced transcripts were discordant in the proteome, showing opposite direction of change. Tau-responsive gene expression networks strongly implicate innate immune activation. Cross-species analyses pinpoint human brain gene perturbations specifically triggered by Tau pathology and/or aging, and further differentiate between disease amplifying and protective changes. Conclusions Our results comprise a powerful, cross-species functional genomics resource for tauopathy, revealing Tau-mediated disruption of gene expression, including dynamic, age-dependent interactions between the brain transcriptome and proteome.
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Affiliation(s)
- Carl Grant Mangleburg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.,Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Timothy Wu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.,Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hari K Yalamanchili
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Caiwei Guo
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yi-Chen Hsieh
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Philip L De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology and Taub Institute for the study of Alzheimer's disease and the aging brain, Columbia University Medical Center, New York, NY, 10032, USA.,Cell Circuits Program, Broad Institute, Cambridge, MA, 02142, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Zhandong Liu
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund St., Suite N.1150, Houston, TX, 77030, USA
| | - Joshua M Shulman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA. .,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund St., Suite N.1150, Houston, TX, 77030, USA. .,Department of Neurology, Baylor College of Medicine, Houston, TX, 77030, USA.
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56
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Diez L, Wegmann S. Nuclear Transport Deficits in Tau-Related Neurodegenerative Diseases. Front Neurol 2020; 11:1056. [PMID: 33101165 PMCID: PMC7546323 DOI: 10.3389/fneur.2020.01056] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/11/2020] [Indexed: 12/14/2022] Open
Abstract
Tau is a cytosolic microtubule binding protein that is highly abundant in the axons of the central nervous system. However, alternative functions of tau also in other cellular compartments are suggested, for example, in the nucleus, where interactions of tau with specific nuclear entities such as DNA, the nucleolus, and the nuclear envelope have been reported. We would like to review the current knowledge about tau-nucleus interactions and lay out possible neurotoxic mechanisms that are based on the (pathological) interactions of tau with the nucleus.
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Affiliation(s)
- Lisa Diez
- German Center for Neurodegenerative Diseases, Berlin, Germany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases, Berlin, Germany
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57
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Lanzillotta C, Zuliani I, Tramutola A, Barone E, Blarzino C, Folgiero V, Caforio M, Valentini D, Villani A, Locatelli F, Butterfield DA, Head E, Perluigi M, Abisambra JF, Di Domenico F. Chronic PERK induction promotes Alzheimer-like neuropathology in Down syndrome: Insights for therapeutic intervention. Prog Neurobiol 2020; 196:101892. [PMID: 32795489 DOI: 10.1016/j.pneurobio.2020.101892] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/30/2020] [Accepted: 08/02/2020] [Indexed: 12/11/2022]
Abstract
A major challenge in neurobiology is the identification of the mechanisms by which protein misfolding leads to cellular toxicity. Many neurodegenerative disorders, in which aberrant protein conformers aggregate into pathological inclusions, present the chronic activation of the PERK branch of the unfolded protein response. The adaptive effects of the PERK pathway include reduction of translation by transient inhibition of eIF2α and antioxidant protein production via induction of Nrf2 transcription factor. In contrast, PERK prolonged activation leads to sustained reduction in protein synthesis and induction of cell death pathways. To further investigate the role of the PERK pathway in neurodegenerative disorders, we focused on Down syndrome (DS), in which aging confers a high risk of Alzheimer disease (AD). By investigating human DS frontal cortices, we found early and sustained PERK activation associated with the induction of eIF2α and ATF4 downstream signals. We also observed that the Nrf2 response is uncoupled from PERK and its antioxidant effects are repressed in a mechanism implicating the transcription repressor Bach1. The pharmacological inhibition of PERK in DS mice reduced eIF2α-related translational repression and promoted Nrf2 nuclear translocation, favoring the rescue of Nrf2/Bach1 imbalance. The further analysis of peripheral cells from living DS individuals provided strong support of the pathological link between PERK and trisomy 21. Our results suggest that failure to regulate the PERK pathway is a peculiar characteristic of DS pathology and it may represent an essential step to promote cellular dysfunction, which actively contributes in the brain to the early development of AD.
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Affiliation(s)
- Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Ilaria Zuliani
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Carla Blarzino
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Valentina Folgiero
- Department of Pediatric Hematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children's Hospital, Rome, Italy
| | - Matteo Caforio
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy; Department of Pediatric Hematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children's Hospital, Rome, Italy
| | - Diletta Valentini
- Pediatric and Infectious Disease Unit, Bambino Gesù Children's Hospital, Rome, Italy
| | - Alberto Villani
- Pediatric and Infectious Disease Unit, Bambino Gesù Children's Hospital, Rome, Italy
| | - Franco Locatelli
- Department of Pediatric Hematology/Oncology and of Cell and Gene Therapy, Bambino Gesù Children's Hospital, Rome, Italy; Department of Pediatrics, Sapienza University of Rome, Rome, Italy
| | - D Allan Butterfield
- Department of Chemistry, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, University of California, Irvine, CA, USA
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
| | - Jose F Abisambra
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, USA
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy.
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58
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Kaniyappan S, Tepper K, Biernat J, Chandupatla RR, Hübschmann S, Irsen S, Bicher S, Klatt C, Mandelkow EM, Mandelkow E. FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments. Mol Neurodegener 2020; 15:39. [PMID: 32677995 PMCID: PMC7364478 DOI: 10.1186/s13024-020-00389-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/08/2020] [Indexed: 01/15/2023] Open
Abstract
Tau aggregation into amyloid fibers based on the cross-beta structure is a hallmark of several Tauopathies, including Alzheimer Disease (AD). Trans-cellular propagation of Tau with pathological conformation has been suggested as a key disease mechanism. This is thought to cause the spreading of Tau pathology in AD by templated conversion of naive Tau in recipient cells into a pathological state, followed by assembly of pathological Tau fibers, similar to the mechanism of nucleated polymerization proposed for prion pathogenesis. In cell cultures, the process is often monitored by a FRET assay where the recipient cell expresses the Tau repeat domain (TauRD) with a pro-aggregant mutation, fused to GFP-based FRET pairs. Since the size of the reporter GFP (barrel of ~ 3 nm × 4 nm) is ~ 7 times larger than the β-strand distance (0.47 nm), this points to a potential steric clash. Hence, we investigated the influence of the GFP tag on TauFL or TauRD aggregation. Using biophysical methods (light scattering, atomic force microscopy (AFM), and scanning-transmission electron microscopy (STEM)), we found that the assembly of TauRD-GFP was severely inhibited and incompatible with that of Alzheimer filaments. These observations argue against the hypothesis that the propagation of Tau pathology in AD is caused by the prion-like templated aggregation of Tau protein, transmitted via cell-to-cell spreading of Tau. Thus, even though the observed local increase of FRET in recipient cells may be a valid hallmark of a pathological reaction, our data argue that it is caused by a process distinct from assembly of TauRD filaments.
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Affiliation(s)
- Senthilvelrajan Kaniyappan
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany. .,Department of Neurodegenerative Diseases and Geriatric Psychiatry, University of Bonn, Bonn, Germany.
| | - Katharina Tepper
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Jacek Biernat
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | | | | | | | | | - Eva-Maria Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany.,CAESAR Research Center, Bonn, Germany
| | - Eckhard Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany. .,CAESAR Research Center, Bonn, Germany.
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59
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Wang X, Allen M, Li S, Quicksall ZS, Patel TA, Carnwath TP, Reddy JS, Carrasquillo MM, Lincoln SJ, Nguyen TT, Malphrus KG, Dickson DW, Crook JE, Asmann YW, Ertekin-Taner N. Deciphering cellular transcriptional alterations in Alzheimer's disease brains. Mol Neurodegener 2020; 15:38. [PMID: 32660529 PMCID: PMC7359236 DOI: 10.1186/s13024-020-00392-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 06/27/2020] [Indexed: 02/06/2023] Open
Abstract
Large-scale brain bulk-RNAseq studies identified molecular pathways implicated in Alzheimer's disease (AD), however these findings can be confounded by cellular composition changes in bulk-tissue. To identify cell intrinsic gene expression alterations of individual cell types, we designed a bioinformatics pipeline and analyzed three AD and control bulk-RNAseq datasets of temporal and dorsolateral prefrontal cortex from 685 brain samples. We detected cell-proportion changes in AD brains that are robustly replicable across the three independently assessed cohorts. We applied three different algorithms including our in-house algorithm to identify cell intrinsic differentially expressed genes in individual cell types (CI-DEGs). We assessed the performance of all algorithms by comparison to single nucleus RNAseq data. We identified consensus CI-DEGs that are common to multiple brain regions. Despite significant overlap between consensus CI-DEGs and bulk-DEGs, many CI-DEGs were absent from bulk-DEGs. Consensus CI-DEGs and their enriched GO terms include genes and pathways previously implicated in AD or neurodegeneration, as well as novel ones. We demonstrated that the detection of CI-DEGs through computational deconvolution methods is promising and highlight remaining challenges. These findings provide novel insights into cell-intrinsic transcriptional changes of individual cell types in AD and may refine discovery and modeling of molecular targets that drive this complex disease.
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Affiliation(s)
- Xue Wang
- Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, FL, USA.
| | - Mariet Allen
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Shaoyu Li
- Department of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Zachary S Quicksall
- Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Tulsi A Patel
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Troy P Carnwath
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Joseph S Reddy
- Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, FL, USA
| | | | - Sarah J Lincoln
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Thuy T Nguyen
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Julia E Crook
- Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Yan W Asmann
- Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Nilüfer Ertekin-Taner
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA.
- Department of Neurology, Mayo Clinic Florida, Jacksonville, FL, USA.
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60
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Mullane K, Williams M. Alzheimer’s disease beyond amyloid: Can the repetitive failures of amyloid-targeted therapeutics inform future approaches to dementia drug discovery? Biochem Pharmacol 2020; 177:113945. [DOI: 10.1016/j.bcp.2020.113945] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/31/2020] [Indexed: 12/12/2022]
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61
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Wang X, Chen K, Pan M, Ge W, He Z. Comparison of proteome alterations during aging in the temporal lobe of humans and rhesus macaques. Exp Brain Res 2020; 238:1963-1976. [PMID: 32572507 DOI: 10.1007/s00221-020-05855-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/11/2020] [Indexed: 01/06/2023]
Abstract
Rhesus macaques are widely used as animal models for studies of the nervous system; however, it is unknown whether the alterations in the protein profile of the brain during aging are conserved between humans and rhesus macaques. In this study, temporal cortex samples from old and young humans (84 vs. 34 years, respectively) or rhesus macaques (20 vs. 6 years, respectively) were subjected to tandem mass tag-labeled proteomic analysis followed by bioinformatic analysis. A total of 3861 homologous pairs of proteins were identified during the aging process. The conservatively upregulated proteins (n = 190) were involved mainly in extracellular matrix (ECM), focal adhesion and coagulation; while, the conservatively downregulated proteins (n = 56) were enriched in ribosome. Network analysis showed that these conservatively regulated proteins interacted with each other with respect to protein synthesis and cytoskeleton-ECM connection. Many proteins in the focal adhesion, blood clotting, complement and coagulation, and cytoplasmic ribosomal protein pathways were regulated in the same direction in human and macaque; while, proteins involved in oligodendrocyte specification and differentiation pathways were downregulated during human aging, and many proteins in the electron transport chain pathway showed differences in the altered expression profiles. Data are available via ProteomeXchange with identifier PXD013597. Our findings suggest similarities in some changes in brain protein profiles during aging both in humans and macaques, although other changes are unique to only one of these species.
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Affiliation(s)
- Xia Wang
- State Key Laboratory of Medical Molecular Biology and Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Kang Chen
- State Key Laboratory of Medical Molecular Biology and Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Meng Pan
- State Key Laboratory of Medical Molecular Biology and Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Wei Ge
- State Key Laboratory of Medical Molecular Biology and Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China. .,Department of Neurosurgery, Affiliated Hospital of Hebei University, Baoding, China.
| | - Zhanlong He
- Yunnan Key Laboratory of Vaccine Research and Development on Severe Infectious Disease, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China.
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Koren SA, Galvis-Escobar S, Abisambra JF. Tau-mediated dysregulation of RNA: Evidence for a common molecular mechanism of toxicity in frontotemporal dementia and other tauopathies. Neurobiol Dis 2020; 141:104939. [PMID: 32413399 DOI: 10.1016/j.nbd.2020.104939] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/10/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023] Open
Abstract
Frontotemporal dementias (FTDs) encompass several disorders commonly characterized by progressive frontotemporal lobar degeneration and dementia. Pathologically, TDP-43, FUS, dipeptide repeats, and tau constitute the protein aggregates in FTD, which in turn coincide with heterogeneity in clinical variants. The underlying molecular etiology explaining the formation of each type of protein aggregate remains unclear; however, dysregulated RNA metabolism rises as a common pathogenic factor. Alongside with TDP-43 and FUS, which bind to and regulate RNA dynamics, emerging data suggest that tau may also regulate RNA metabolism and translation. The complex mechanisms that drive translational selectivity in turn regulate the broad clinical presentation of FTDs. Here, we focus on the enigmatic relationship between tau and RNA and review the mechanisms of tau-mediated dysregulation of RNA in tauopathies such as FTD.
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Affiliation(s)
- Shon A Koren
- Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, BOX 100159, 1275 Center Drive, University of Florida, Gainesville, FL 32610, United States of America
| | - Sara Galvis-Escobar
- Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, BOX 100159, 1275 Center Drive, University of Florida, Gainesville, FL 32610, United States of America
| | - Jose F Abisambra
- Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, BOX 100159, 1275 Center Drive, University of Florida, Gainesville, FL 32610, United States of America.
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63
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Webber CJ, Lei SE, Wolozin B. The pathophysiology of neurodegenerative disease: Disturbing the balance between phase separation and irreversible aggregation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:187-223. [PMID: 32828466 DOI: 10.1016/bs.pmbts.2020.04.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Liquid-liquid phase separation (LLPS) brings together functionally related proteins through the intrinsic biophysics of proteins in a process that is driven by reducing free energy and maximizing entropy. The process of LLPS allows proteins to form structures, termed membrane-less organelles. These diverse, dynamic organelles are active in a wide range of processes in the nucleus, cytoplasm, mitochondria and synapse, and ranging from bacteria to plants to eukaryotes. RNA and DNA present long chained charged polymers that promote LLPS. Consequently, many RNA binding proteins (RBPs) and DNA binding proteins form membrane-less organelles. However, the highly concentrated phase separated state creates conditions that also promote formation of irreversible protein aggregates. Mutations in RNA and DNA binding proteins that increase the stability of irreversible aggregates also increase the accumulation of irreversible aggregates directly and from membrane-less organelles. Many of the RBPs that exhibit disease-linked mutations carry out cytoplasmic actions through stress granules, which are a pleiotropic type of RNA granule that regulates the translational response to stress. Phosphorylation and oligomerization of tau facilitates its interactions with RBPs and ribosomal proteins, affecting RNA translation; we propose that this is a major reason that tau becomes phosphorylated with stress. Persistent stress leads to the accumulation of irreversible aggregates composed of RBPs or tau, which then cause toxicity and form many of the hallmark pathologies of major neurodegenerative diseases. This pathophysiology ultimately leads to multiple forms of neurodegenerative diseases, the specific type of which reflects the temporal and spatial accumulation of different aggregating proteins.
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Affiliation(s)
- Chelsea J Webber
- Department of Pharmacology, Boston University School of Medicine, Boston, MA, United States
| | - Shuwen Eric Lei
- Department of Pharmacology, Boston University School of Medicine, Boston, MA, United States
| | - Benjamin Wolozin
- Department of Pharmacology, Boston University School of Medicine, Boston, MA, United States; Department of Neurology, Boston University School of Medicine, Boston, MA, United States; Program in Neuroscience, Boston University, Boston, MA, United States; Neurophotonics Center, Boston University, Boston, MA, United States.
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64
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The science of puromycin: From studies of ribosome function to applications in biotechnology. Comput Struct Biotechnol J 2020; 18:1074-1083. [PMID: 32435426 PMCID: PMC7229235 DOI: 10.1016/j.csbj.2020.04.014] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/19/2020] [Accepted: 04/19/2020] [Indexed: 11/20/2022] Open
Abstract
Puromycin is a naturally occurring aminonucleoside antibiotic that inhibits protein synthesis by ribosome-catalyzed incorporation into the C-terminus of elongating nascent chains, blocking further extension and resulting in premature termination of translation. It is most commonly known as a selection marker for cell lines genetically engineered to express a resistance transgene, but its additional uses as a probe for protein synthesis have proven invaluable across a wide variety of model systems, ranging from purified ribosomes and cell-free translation to intact cultured cells and whole animals. Puromycin is comprised of a nucleoside covalently bound to an amino acid, mimicking the 3′ end of aminoacylated tRNAs that participate in delivery of amino acids to elongating ribosomes. Both moieties can tolerate some chemical substitutions and modifications without significant loss of activity, generating a diverse toolbox of puromycin-based reagents with added functionality, such as biotin for affinity purification or fluorophores for fluorescent microscopy detection. These reagents, as well as anti-puromycin antibodies, have played a pivotal role in advancing our understanding of the regulation and dysregulation of protein synthesis in normal and pathological processes, including immune response and neurological function. This manuscript reviews the current state of puromycin-based research, including structure and mechanism of action, relevant derivatives, use in advanced methodologies and some of the major insights generated using such techniques both in the lab and the clinic.
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65
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Dillon GM, Henderson JL, Bao C, Joyce JA, Calhoun M, Amaral B, King KW, Bajrami B, Rabah D. Acute inhibition of the CNS-specific kinase TTBK1 significantly lowers tau phosphorylation at several disease relevant sites. PLoS One 2020; 15:e0228771. [PMID: 32255788 PMCID: PMC7138307 DOI: 10.1371/journal.pone.0228771] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
Hyperphosphorylated tau protein is a pathological hallmark of numerous neurodegenerative diseases and the level of tau pathology is correlated with the degree of cognitive impairment. Tau hyper-phosphorylation is thought to be an early initiating event in the cascade leading to tau toxicity and neuronal death. Inhibition of tau phosphorylation therefore represents an attractive therapeutic strategy. However, the widespread expression of most kinases and promiscuity of their substrates, along with poor selectivity of most kinase inhibitors, have resulted in systemic toxicities that have limited the advancement of tau kinase inhibitors into the clinic. We therefore focused on the CNS-specific tau kinase, TTBK1, and investigated whether selective inhibition of this kinase could represent a viable approach to targeting tau phosphorylation in disease. In the current study, we demonstrate that TTBK1 regulates tau phosphorylation using overexpression or knockdown of this kinase in heterologous cells and primary neurons. Importantly, we find that TTBK1-specific phosphorylation of tau leads to a loss of normal protein function including a decrease in tau-tubulin binding and deficits in tubulin polymerization. We then describe the use of a novel, selective small molecule antagonist, BIIB-TTBK1i, to study the acute effects of TTBK1 inhibition on tau phosphorylation in vivo. We demonstrate substantial lowering of tau phosphorylation at multiple sites implicated in disease, suggesting that TTBK1 inhibitors may represent an exciting new approach in the search for neurodegenerative disease therapies.
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Affiliation(s)
| | | | - Channa Bao
- Biogen, Cambridge, MA, United States of America
| | | | | | | | | | | | - Dania Rabah
- Biogen, Cambridge, MA, United States of America
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66
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Corsetti V, Borreca A, Latina V, Giacovazzo G, Pignataro A, Krashia P, Natale F, Cocco S, Rinaudo M, Malerba F, Florio R, Ciarapica R, Coccurello R, D’Amelio M, Ammassari-Teule M, Grassi C, Calissano P, Amadoro G. Passive immunotherapy for N-truncated tau ameliorates the cognitive deficits in two mouse Alzheimer's disease models. Brain Commun 2020; 2:fcaa039. [PMID: 32954296 PMCID: PMC7425324 DOI: 10.1093/braincomms/fcaa039] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/05/2020] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
Clinical and neuropathological studies have shown that tau pathology better correlates with the severity of dementia than amyloid plaque burden, making tau an attractive target for the cure of Alzheimer's disease. We have explored whether passive immunization with the 12A12 monoclonal antibody (26-36aa of tau protein) could improve the Alzheimer's disease phenotype of two well-established mouse models, Tg2576 and 3xTg mice. 12A12 is a cleavage-specific monoclonal antibody which selectively binds the pathologically relevant neurotoxic NH226-230 fragment (i.e. NH2htau) of tau protein without cross-reacting with its full-length physiological form(s). We found out that intravenous administration of 12A12 monoclonal antibody into symptomatic (6 months old) animals: (i) reaches the hippocampus in its biologically active (antigen-binding competent) form and successfully neutralizes its target; (ii) reduces both pathological tau and amyloid precursor protein/amyloidβ metabolisms involved in early disease-associated synaptic deterioration; (iii) improves episodic-like type of learning/memory skills in hippocampal-based novel object recognition and object place recognition behavioural tasks; (iv) restores the specific up-regulation of the activity-regulated cytoskeleton-associated protein involved in consolidation of experience-dependent synaptic plasticity; (v) relieves the loss of dendritic spine connectivity in pyramidal hippocampal CA1 neurons; (vi) rescues the Alzheimer's disease-related electrophysiological deficits in hippocampal long-term potentiation at the CA3-CA1 synapses; and (vii) mitigates the neuroinflammatory response (reactive gliosis). These findings indicate that the 20-22 kDa NH2-terminal tau fragment is crucial target for Alzheimer's disease therapy and prospect immunotherapy with 12A12 monoclonal antibody as safe (normal tau-preserving), beneficial approach in contrasting the early Amyloidβ-dependent and independent neuropathological and cognitive alterations in affected subjects.
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Affiliation(s)
| | - Antonella Borreca
- Humanitas University Laboratory of Pharmacology and Brain Pathology, Neuro Center, 20089 Milan, Italy
- Institute of Neuroscience, 20129 Milan, Italy
| | | | | | | | - Paraskevi Krashia
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Department of Medicine, University Campus Bio-Medico, 00128 Rome, Italy
- Department of Science and Technology for Humans and Environment, University Campus Bio-medico, 00128 Rome, Italy
| | - Francesca Natale
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Sara Cocco
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Marco Rinaudo
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | | | - Rita Florio
- European Brain Research Institute (EBRI), 00161 Rome, Italy
| | | | - Roberto Coccurello
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Institute for Complex Systems (ISC), CNR, 00185 Rome, Italy
| | - Marcello D’Amelio
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Department of Medicine, University Campus Bio-Medico, 00128 Rome, Italy
- Department of Science and Technology for Humans and Environment, University Campus Bio-medico, 00128 Rome, Italy
| | | | - Claudio Grassi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | | | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), 00161 Rome, Italy
- Institute of Translational Pharmacology (IFT)–National Research Council (CNR), 00133 Rome, Italy
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67
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Banerjee S, Ferdosh S, Ghosh AN, Barat C. Tau protein- induced sequestration of the eukaryotic ribosome: Implications in neurodegenerative disease. Sci Rep 2020; 10:5225. [PMID: 32251304 PMCID: PMC7090008 DOI: 10.1038/s41598-020-61777-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/28/2020] [Indexed: 12/15/2022] Open
Abstract
The human tau is a microtubule-associated intrinsically unstructured protein that forms intraneuronal cytotoxic deposits in neurodegenerative diseases, like tauopathies. Recent studies indicate that in Alzheimer's disease, ribosomal dysfunction might be a crucial event in the disease pathology. Our earlier studies had demonstrated that amorphous protein aggregation in the presence of ribosome can lead to sequestration of the ribosomal components. The present study aims at determining the effect of incubation of the full-length tau protein (Ht40) and its microtubule binding 4-repeat domain (K18) on the eukaryotic ribosome. Our in vitro studies show that incubation of Ht40 and the K18 tau variants with isolated non-translating yeast ribosome can induce a loss of ribosome physical integrity resulting in formation of tau-rRNA-ribosomal protein aggregates. Incubation with the tau protein variants also led to a disappearance of the peak indicating the ribosome profile of the HeLa cell lysate and suppression of translation in the human in vitro translation system. The incubation of tau protein with the ribosomal RNA leads to the formation of tau-rRNA aggregates. The effect of K18 on the yeast ribosome can be mitigated in the presence of cellular polyanions like heparin and tRNA, thereby indicating the electrostatic nature of the aggregation process.
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Affiliation(s)
- Senjuti Banerjee
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Sehnaz Ferdosh
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Amar Nath Ghosh
- National Institute of Cholera and Enteric Diseases P-33, C.I.T. Road, Scheme XM, Beleghata, India
| | - Chandana Barat
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India.
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68
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The effects of mild closed head injuries on tauopathy and cognitive deficits in rodents: Primary results in wild type and rTg4510 mice, and a systematic review. Exp Neurol 2020; 326:113180. [PMID: 31930992 DOI: 10.1016/j.expneurol.2020.113180] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 12/02/2019] [Accepted: 01/09/2020] [Indexed: 12/17/2022]
Abstract
In humans, the majority of sustained traumatic brain injuries (TBIs) are classified as 'mild' and most often a result of a closed head injury (CHI). The effects of a non-penetrating CHI are not benign and may lead to chronic pathology and behavioral dysfunction, which could be worsened by repeated head injury. Clinical-neuropathological correlation studies provide evidence that conversion of tau into abnormally phosphorylated proteotoxic intermediates (p-tau) could be part of the pathophysiology triggered by a single TBI and enhanced by repeated TBIs. However, the link between p-tau and CHI in rodents remains controversial. To address this question experimentally, we induced a single CHI or two CHIs to WT or rTg4510 mice. We found that 2× CHI increased tau phosphorylation in WT mice and rTg4510 mice. Behavioral characterization in WT mice found chronic deficits in the radial arm water maze in 2× CHI mice that had partially resolved in the 1× CHI mice. Moreover, using Manganese-Enhanced Magnetic Resonance Imaging with R1 mapping - a novel functional neuroimaging technique - we found greater deficits in the rTg4510 mice following 2× CHI compared to 1× CHI. To integrate our findings with prior work in the field, we conducted a systematic review of rodent mild repetitive CHI studies. Following Prisma guidelines, we identified 25 original peer-reviewed papers. Results from our experiments, as well as our systematic review, provide compelling evidence that tau phosphorylation is modified by experimental mild TBI studies; however, changes in p-tau levels are not universally reported. Together, our results provide evidence that repetitive TBIs can result in worse and more persistent neurological deficits compared to a single TBI, but the direct link between the worsened outcome and elevated p-tau could not be established.
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69
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Dar KB, Bhat AH, Amin S, Reshi BA, Zargar MA, Masood A, Ganie SA. Elucidating Critical Proteinopathic Mechanisms and Potential Drug Targets in Neurodegeneration. Cell Mol Neurobiol 2019; 40:313-345. [PMID: 31584139 DOI: 10.1007/s10571-019-00741-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/06/2019] [Indexed: 12/18/2022]
Abstract
Neurodegeneration entails progressive loss of neuronal structure as well as function leading to cognitive failure, apathy, anxiety, irregular body movements, mood swing and ageing. Proteomic dysregulation is considered the key factor for neurodegeneration. Mechanisms involving deregulated processing of proteins such as amyloid beta (Aβ) oligomerization; tau hyperphosphorylation, prion misfolding; α-synuclein accumulation/lewy body formation, chaperone deregulation, acetylcholine depletion, adenosine 2A (A2A) receptor hyperactivation, secretase deregulation, leucine-rich repeat kinase 2 (LRRK2) mutation and mitochondrial proteinopathies have deeper implications in neurodegenerative disorders. Better understanding of such pathological mechanisms is pivotal for exploring crucial drug targets. Herein, we provide a comprehensive outlook about the diverse proteomic irregularities in Alzheimer's, Parkinson's and Creutzfeldt Jakob disease (CJD). We explicate the role of key neuroproteomic drug targets notably Aβ, tau, alpha synuclein, prions, secretases, acetylcholinesterase (AchE), LRRK2, molecular chaperones, A2A receptors, muscarinic acetylcholine receptors (mAchR), N-methyl-D-aspartate receptor (NMDAR), glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) and mitochondrial/oxidative stress-related proteins for combating neurodegeneration and associated cognitive and motor impairment. Cross talk between amyloidopathy, synucleinopathy, tauopathy and several other proteinopathies pinpoints the need to develop safe therapeutics with ability to strike multiple targets in the aetiology of the neurodegenerative disorders. Therapeutics like microtubule stabilisers, chaperones, kinase inhibitors, anti-aggregation agents and antibodies could serve promising regimens for treating neurodegeneration. However, drugs should be target specific, safe and able to penetrate blood-brain barrier.
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Affiliation(s)
- Khalid Bashir Dar
- Department of Clinical Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India.,Department of Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Aashiq Hussain Bhat
- Department of Clinical Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India.,Department of Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Shajrul Amin
- Department of Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Bilal Ahmad Reshi
- Department of Biotechnology, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Mohammad Afzal Zargar
- Department of Clinical Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Akbar Masood
- Department of Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India
| | - Showkat Ahmad Ganie
- Department of Clinical Biochemistry, Faculty of Biological Sciences, University of Kashmir, Srinagar, India.
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70
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Drosophila Tau Negatively Regulates Translation and Olfactory Long-Term Memory, But Facilitates Footshock Habituation and Cytoskeletal Homeostasis. J Neurosci 2019; 39:8315-8329. [PMID: 31488613 DOI: 10.1523/jneurosci.0391-19.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/24/2019] [Accepted: 08/07/2019] [Indexed: 01/07/2023] Open
Abstract
Although the involvement of pathological tau in neurodegenerative dementias is indisputable, its physiological roles have remained elusive in part because its abrogation has been reported without overt phenotypes in mice and Drosophila This was addressed using the recently described Drosophila tauKO and Mi{MIC} mutants and focused on molecular and behavioral analyses. Initially, we show that Drosophila tau (dTau) loss precipitates dynamic cytoskeletal changes in the adult Drosophila CNS and translation upregulation. Significantly, we demonstrate for the first time distinct roles for dTau in adult mushroom body (MB)-dependent neuroplasticity as its downregulation within α'β'neurons impairs habituation. In accord with its negative regulation of translation, dTau loss specifically enhances protein synthesis-dependent long-term memory (PSD-LTM), but not anesthesia-resistant memory. In contrast, elevation of the protein in the MBs yielded premature habituation and depressed PSD-LTM. Therefore, tau loss in Drosophila dynamically alters brain cytoskeletal dynamics and profoundly affects neuronal proteostasis and plasticity.SIGNIFICANCE STATEMENT We demonstrate that despite modest sequence divergence, the Drosophila tau (dTau) is a true vertebrate tau ortholog as it interacts with the neuronal microtubule and actin cytoskeleton. Novel physiological roles for dTau in regulation of translation, long-term memory, and footshock habituation are also revealed. These emerging insights on tau physiological functions are invaluable for understanding the molecular pathways and processes perturbed in tauopathies.
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71
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Koren SA, Gillett DA, D'Alton SV, Hamm MJ, Abisambra JF. Proteomic Techniques to Examine Neuronal Translational Dynamics. Int J Mol Sci 2019; 20:ijms20143524. [PMID: 31323794 PMCID: PMC6678648 DOI: 10.3390/ijms20143524] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/08/2019] [Accepted: 07/15/2019] [Indexed: 01/30/2023] Open
Abstract
Impairments in translation have been increasingly implicated in the pathogenesis and progression of multiple neurodegenerative diseases. Assessing the spatiotemporal dynamics of translation in the context of disease is a major challenge. Recent developments in proteomic analyses have enabled the resolution of nascent peptides in a short timescale on the order of minutes. In addition, a quantitative analysis of translation has progressed in vivo, showing remarkable potential for coupling these techniques with cognitive and behavioral outcomes. Here, we review these modern approaches to measure changes in translation and ribosomal function with a specific focus on current applications in the mammalian brain and in the study of neurodegenerative diseases.
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Affiliation(s)
- Shon A Koren
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32601, USA
| | - Drew A Gillett
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32601, USA
| | - Simon V D'Alton
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32601, USA
| | - Matthew J Hamm
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32601, USA
| | - Jose F Abisambra
- Department of Neuroscience and Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32601, USA.
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