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Erdogdu B, Varabyou A, Hicks SC, Salzberg SL, Pertea M. Detecting differential transcript usage in complex diseases with SPIT. CELL REPORTS METHODS 2024; 4:100736. [PMID: 38508189 PMCID: PMC10985272 DOI: 10.1016/j.crmeth.2024.100736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/21/2023] [Accepted: 02/27/2024] [Indexed: 03/22/2024]
Abstract
Differential transcript usage (DTU) plays a crucial role in determining how gene expression differs among cells, tissues, and developmental stages, contributing to the complexity and diversity of biological systems. In abnormal cells, it can also lead to deficiencies in protein function and underpin disease pathogenesis. Analyzing DTU via RNA sequencing (RNA-seq) data is vital, but the genetic heterogeneity in populations with complex diseases presents an intricate challenge due to diverse causal events and undetermined subtypes. Although the majority of common diseases in humans are categorized as complex, state-of-the-art DTU analysis methods often overlook this heterogeneity in their models. We therefore developed SPIT, a statistical tool that identifies predominant subgroups in transcript usage within a population along with their distinctive sets of DTU events. This study provides comprehensive assessments of SPIT's methodology and applies it to analyze brain samples from individuals with schizophrenia, revealing previously unreported DTU events in six candidate genes.
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Affiliation(s)
- Beril Erdogdu
- Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering, Baltimore, MD, USA.
| | - Ales Varabyou
- Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering, Baltimore, MD, USA; Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA
| | - Stephanie C Hicks
- Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering, Baltimore, MD, USA; Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Malone Center for Engineering in Healthcare, Johns Hopkins University, Baltimore, MD, USA
| | - Steven L Salzberg
- Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering, Baltimore, MD, USA; Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA; Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Mihaela Pertea
- Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering, Baltimore, MD, USA; Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA; Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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2
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Falker-Gieske C. Transcriptome driven discovery of novel candidate genes for human neurological disorders in the telomer-to-telomer genome assembly era. Hum Genomics 2023; 17:94. [PMID: 37872607 PMCID: PMC10594789 DOI: 10.1186/s40246-023-00543-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 10/17/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND With the first complete draft of a human genome, the Telomere-to-Telomere Consortium unlocked previously concealed genomic regions for genetic analyses. These regions harbour nearly 2000 potential novel genes with unknown function. In order to uncover candidate genes associated with human neurological pathologies, a comparative transcriptome study using the T2T-CHM13 and the GRCh38 genome assemblies was conducted on previously published datasets for eight distinct human neurological disorders. RESULTS The analysis of differential expression in RNA sequencing data led to the identification of 336 novel candidate genes linked to human neurological disorders. Additionally, it was revealed that, on average, 3.6% of the differentially expressed genes detected with the GRCh38 assembly may represent potential false positives. Among the noteworthy findings, two novel genes were discovered, one encoding a pore-structured protein and the other a highly ordered β-strand-rich protein. These genes exhibited upregulation in multiple epilepsy datasets and hold promise as candidate genes potentially modulating the progression of the disease. Furthermore, an analysis of RNA derived from white matter lesions in multiple sclerosis patients indicated significant upregulation of 26 rRNA encoding genes. Additionally, putative pathology related genes were identified for Alzheimer's disease, amyotrophic lateral sclerosis, glioblastoma, glioma, and conditions resulting from the m.3242 A > G mtDNA mutation. CONCLUSION The results presented here underline the potential of the T2T-CHM13 assembly in facilitating the discovery of candidate genes from transcriptome data in the context of human disorders. Moreover, the results demonstrate the value of remapping sequencing data to a superior genome assembly. Numerous potential pathology related genes, either as causative factors or related elements, have been unveiled, warranting further experimental validation.
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Affiliation(s)
- Clemens Falker-Gieske
- Division of Functional Breeding, Department of Animal Sciences, Georg-August-Universität Göttingen, Burckhardtweg 2, 37077, Göttingen, Germany.
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3
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Erdogdu B, Varabyou A, Hicks SC, Salzberg SL, Pertea M. Detecting differential transcript usage in complex diseases with SPIT. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548289. [PMID: 37503064 PMCID: PMC10369883 DOI: 10.1101/2023.07.10.548289] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Differential transcript usage (DTU) plays a crucial role in determining how gene expression differs among cells, tissues, and different developmental stages, thereby contributing to the complexity and diversity of biological systems. In abnormal cells, it can also lead to deficiencies in protein function, potentially leading to pathogenesis of diseases. Detecting such events for single-gene genetic traits is relatively uncomplicated; however, the heterogeneity of populations with complex diseases presents an intricate challenge due to the presence of diverse causal events and undetermined subtypes. SPIT is the first statistical tool that quantifies the heterogeneity in transcript usage within a population and identifies predominant subgroups along with their distinctive sets of DTU events. We provide comprehensive assessments of SPIT's methodology in both single-gene and complex traits and report the results of applying SPIT to analyze brain samples from individuals with schizophrenia. Our analysis reveals previously unreported DTU events in six candidate genes.
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Affiliation(s)
- Beril Erdogdu
- Center for Computational Biology, Johns Hopkins University; Baltimore, MD, United States
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering; Baltimore, MD, United States
| | - Ales Varabyou
- Center for Computational Biology, Johns Hopkins University; Baltimore, MD, United States
- Department of Computer Science, Johns Hopkins University; Baltimore, MD, United States
| | - Stephanie C Hicks
- Center for Computational Biology, Johns Hopkins University; Baltimore, MD, United States
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, MD, USA
- Malone Center for Engineering in Healthcare, Johns Hopkins University, MD, USA
| | - Steven L Salzberg
- Center for Computational Biology, Johns Hopkins University; Baltimore, MD, United States
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering; Baltimore, MD, United States
- Department of Computer Science, Johns Hopkins University; Baltimore, MD, United States
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, MD, USA
- Department of Genetic Medicine, Johns Hopkins School of Medicine; Baltimore, MD, United States
| | - Mihaela Pertea
- Center for Computational Biology, Johns Hopkins University; Baltimore, MD, United States
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of Engineering; Baltimore, MD, United States
- Department of Computer Science, Johns Hopkins University; Baltimore, MD, United States
- Department of Genetic Medicine, Johns Hopkins School of Medicine; Baltimore, MD, United States
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4
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Jiao L, Liu Y, Yu XY, Pan X, Zhang Y, Tu J, Song YH, Li Y. Ribosome biogenesis in disease: new players and therapeutic targets. Signal Transduct Target Ther 2023; 8:15. [PMID: 36617563 PMCID: PMC9826790 DOI: 10.1038/s41392-022-01285-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/01/2022] [Accepted: 12/08/2022] [Indexed: 01/10/2023] Open
Abstract
The ribosome is a multi-unit complex that translates mRNA into protein. Ribosome biogenesis is the process that generates ribosomes and plays an essential role in cell proliferation, differentiation, apoptosis, development, and transformation. The mTORC1, Myc, and noncoding RNA signaling pathways are the primary mediators that work jointly with RNA polymerases and ribosome proteins to control ribosome biogenesis and protein synthesis. Activation of mTORC1 is required for normal fetal growth and development and tissue regeneration after birth. Myc is implicated in cancer development by enhancing RNA Pol II activity, leading to uncontrolled cancer cell growth. The deregulation of noncoding RNAs such as microRNAs, long noncoding RNAs, and circular RNAs is involved in developing blood, neurodegenerative diseases, and atherosclerosis. We review the similarities and differences between eukaryotic and bacterial ribosomes and the molecular mechanism of ribosome-targeting antibiotics and bacterial resistance. We also review the most recent findings of ribosome dysfunction in COVID-19 and other conditions and discuss the consequences of ribosome frameshifting, ribosome-stalling, and ribosome-collision. We summarize the role of ribosome biogenesis in the development of various diseases. Furthermore, we review the current clinical trials, prospective vaccines for COVID-19, and therapies targeting ribosome biogenesis in cancer, cardiovascular disease, aging, and neurodegenerative disease.
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Affiliation(s)
- Lijuan Jiao
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Yuzhe Liu
- grid.452829.00000000417660726Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin 130000 P. R. China
| | - Xi-Yong Yu
- grid.410737.60000 0000 8653 1072Key Laboratory of Molecular Target & Clinical Pharmacology and the NMPA State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, Guangdong 511436 P. R. China
| | - Xiangbin Pan
- grid.506261.60000 0001 0706 7839Department of Structural Heart Disease, National Center for Cardiovascular Disease, China & Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P. R. China ,Key Laboratory of Cardiovascular Appratus Innovation, Beijing, 100037 P. R. China
| | - Yu Zhang
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Junchu Tu
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Yao-Hua Song
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, National Clinical Research Center for Hematologic Diseases, the First Affiliated Hospital of Soochow University, Suzhou, P. R. China. .,State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, P. R. China.
| | - Yangxin Li
- Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
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5
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Turi Z, Lacey M, Mistrik M, Moudry P. Impaired ribosome biogenesis: mechanisms and relevance to cancer and aging. Aging (Albany NY) 2020; 11:2512-2540. [PMID: 31026227 PMCID: PMC6520011 DOI: 10.18632/aging.101922] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/04/2019] [Indexed: 02/06/2023]
Abstract
The biosynthesis of ribosomes is a complex process that requires the coordinated action of many factors and a huge energy investment from the cell. Ribosomes are essential for protein production, and thus for cellular survival, growth and proliferation. Ribosome biogenesis is initiated in the nucleolus and includes: the synthesis and processing of ribosomal RNAs, assembly of ribosomal proteins, transport to the cytoplasm and association of ribosomal subunits. The disruption of ribosome biogenesis at various steps, with either increased or decreased expression of different ribosomal components, can promote cell cycle arrest, senescence or apoptosis. Additionally, interference with ribosomal biogenesis is often associated with cancer, aging and age-related degenerative diseases. Here, we review current knowledge on impaired ribosome biogenesis, discuss the main factors involved in stress responses under such circumstances and focus on examples with clinical relevance.
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Affiliation(s)
- Zsofia Turi
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Matthew Lacey
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Martin Mistrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Pavel Moudry
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
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Ahmad SO, Baun J, Tipton B, Tate Y, Switzer RC. Modification of AgNOR staining to reveal the nucleolus in thick sections specified for stereological and pathological assessments of brain tissue. Heliyon 2019; 5:e03047. [PMID: 31886432 PMCID: PMC6921121 DOI: 10.1016/j.heliyon.2019.e03047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/20/2019] [Accepted: 12/11/2019] [Indexed: 12/02/2022] Open
Abstract
Background Various stains have been devised to reveal degenerative or reactive cell phenotypes, or the disintegrative and/or neuropathic lesions associated with Alzheimer's, Parkinson's, and Pick's diseases, Down's syndrome, or chemical toxicity. Utilization of silver staining has allowed researchers to elucidate neural pathways promoting a greater understanding of the functional connections between brain regions. All of these methods employing silver can be characterized as ‘directed staining technologies’. New methods The argyrophilic proteins (AgNOR) staining protocol was modified to stain nucleoli in thick sections prepared for stereological evaluation of brain tissue. Nucleoli appeared as black dots against a pale amber background. Tissue sections were counterstained with Toluidine Blue, or reduced-strength Tyrosine Hydroxylase immunohistochemistry to facilitate visualization of basic cellular morphology and regional nucleus identification. Here, we present a modified method for nucleolar staining in free-floating thick sections of brain embedded in a gelatin matrix. The modifications in our procedure include incubation in HCl to denature (‘unravel’) the DNA, a bleaching step to reduce non-specific background silver staining, and counterstaining with Toluidine Blue or reduced-strength tyrosine hydroxylase immunohistochemistry. Comparison with old methods Prior to the development of immunohistochemistry, silver staining was used primarily to identify pathological profiles and trace axon pathways; however, in many cases, a combination of silver staining and immunohistochemistry are required to fully visualize pathomorphology. The mechanism of these stains requires the binding of silver ions to cellular components and the subsequent reduction of the ions to metallic silver. Dilutions of TH primary antibody were evaluated to maximize identification of neurons and the nucleolus amongst the soma and processes present in the thick section. The use of stereology as a tool to estimate cell number has become increasingly prevalent in neuroscience experiments. As requirements for the preparation of experimental tissue have been refined, researchers have begun to use thicker sections, between 40 to 80 microns, to increase the number of optical planes available for analysis. These thick sections require modified staining protocols to assure complete penetration of stains throughout the tissue section. Conclusions This method is particularly useful in nucleolar identification for Stereology, and automated counting methods. Use of the nucleolus avoids some of the problems associated with use of the nucleus. The nucleolus is smaller than the nucleus and is less susceptible to transection during sectioning. It has a higher density than the nucleus and is easier to visualize. It is generally darker staining than the immunohistochemical reaction product that provides the identification marker for the cells to be counted. Examples of the method in several brain sections of the rat are shown, though the method has been also proven in other mammalian models.
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Affiliation(s)
- S O Ahmad
- Doisy College of Health Sciences, St. Louis University, St. Louis, MO and the Virginia Gore NeuroOccupation Lab, 63104, USA
| | - J Baun
- NeuroScience Associates, Knoxville, 37934, TN, USA
| | - B Tipton
- NeuroScience Associates, Knoxville, 37934, TN, USA
| | - Y Tate
- NeuroScience Associates, Knoxville, 37934, TN, USA
| | - R C Switzer
- NeuroScience Associates, Knoxville, 37934, TN, USA
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7
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Kreiner G, Sönmez A, Liss B, Parlato R. Integration of the Deacetylase SIRT1 in the Response to Nucleolar Stress: Metabolic Implications for Neurodegenerative Diseases. Front Mol Neurosci 2019; 12:106. [PMID: 31110473 PMCID: PMC6499230 DOI: 10.3389/fnmol.2019.00106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/09/2019] [Indexed: 01/10/2023] Open
Abstract
Understanding underlying mechanisms of neurodegenerative diseases is fundamental to develop effective therapeutic intervention. Yet they remain largely elusive, but metabolic, and transcriptional dysregulation are common events. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent lysine deacetylase, regulating transcription, and critical for the cellular adaptations to metabolic stress. SIRT1 regulates the transcription of ribosomal RNA (rRNA), connecting the energetic state with cell growth and function. The activity of the transcription initiation factor-IA (TIF-IA) is important for the transcriptional regulation of ribosomal DNA (rDNA) genes in the nucleolus, and is also sensitive to changes in the cellular energetic state. Moreover, TIF-IA is responsive to nutrient-deprivation, neurotrophic stimulation, and oxidative stress. Hence, both SIRT1 and TIF-IA connect changes in cellular stress with transcriptional regulation and metabolic adaptation. Moreover, they finely tune the activity of the transcription factor p53, maintain mitochondrial function, and oxidative stress responses. Here we reviewed and discussed evidence that SIRT1 and TIF-IA are regulated by shared pathways and their activities preserve neuronal homeostasis in response to metabolic stressors. We provide evidence that loss of rDNA transcription due to altered TIF-IA function alters SIRT1 expression and propose a model of interdependent feedback mechanisms. An imbalance of this signaling might be a critical common event in neurodegenerative diseases. In conclusion, we provide a novel perspective for the prediction of the therapeutic benefits of the modulation of SIRT1- and nucleolar-dependent pathways in metabolic and neurodegenerative diseases.
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Affiliation(s)
- Grzegorz Kreiner
- Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Aynur Sönmez
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.,New College, Oxford University, Oxford, United Kingdom
| | - Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.,Department of Medical Cell Biology, Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany
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Tuorto F, Parlato R. rRNA and tRNA Bridges to Neuronal Homeostasis in Health and Disease. J Mol Biol 2019; 431:1763-1779. [PMID: 30876917 DOI: 10.1016/j.jmb.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/25/2019] [Accepted: 03/06/2019] [Indexed: 12/11/2022]
Abstract
Dysregulation of protein translation is emerging as a unifying mechanism in the pathogenesis of many neuronal disorders. Ribosomal RNA (rRNA) and transfer RNA (tRNA) are structural molecules that have complementary and coordinated functions in protein synthesis. Defects in both rRNAs and tRNAs have been described in mammalian brain development, neurological syndromes, and neurodegeneration. In this review, we present the molecular mechanisms that link aberrant rRNA and tRNA transcription, processing and modifications to translation deficits, and neuropathogenesis. We also discuss the interdependence of rRNA and tRNA biosynthesis and how their metabolism brings together proteotoxic stress and impaired neuronal homeostasis.
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Affiliation(s)
- Francesca Tuorto
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
| | - Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Albert Einstein Allee 11, 89081 Ulm, Germany; Institute of Anatomy and Cell Biology, Medical Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany.
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Abstract
The nucleolus is a prominent subnuclear compartment, where ribosome biosynthesis takes place. Recently, the nucleolus has gained attention for its novel role in the regulation of cellular stress. Nucleolar stress is emerging as a new concept, which is characterized by diverse cellular insult-induced abnormalities in nucleolar structure and function, ultimately leading to activation of p53 or other stress signaling pathways and alterations in cell behavior. Despite a number of comprehensive reviews on this concept, straightforward and clear-cut way criteria for a nucleolar stress state, regarding the factors that elicit this state, the morphological and functional alterations as well as the rationale for p53 activation are still missing. Based on literature of the past two decades, we herein summarize the evolution of the concept and provide hallmarks of nucleolar stress. Along with updated information and thorough discussion of existing confusions in the field, we pay particular attention to the current understanding of the sensing mechanisms, i.e., how stress is integrated by p53. In addition, we propose our own emphasis regarding the role of nucleolar protein NPM1 in the hallmarks of nucleolar stress and sensing mechanisms. Finally, the links of nucleolar stress to human diseases are briefly and selectively introduced.
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Affiliation(s)
- Kai Yang
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China.,Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
| | - Jie Yang
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
| | - Jing Yi
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
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Gasparotto J, Ribeiro CT, Bortolin RC, Somensi N, Rabelo TK, Kunzler A, Souza NC, Pasquali MADB, Moreira JCF, Gelain DP. Targeted inhibition of RAGE in substantia nigra of rats blocks 6-OHDA-induced dopaminergic denervation. Sci Rep 2017; 7:8795. [PMID: 28821831 PMCID: PMC5562811 DOI: 10.1038/s41598-017-09257-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 07/19/2017] [Indexed: 11/18/2022] Open
Abstract
The receptor for advanced glycation endproducts (RAGE) is a pattern-recognition receptor associated with inflammation in most cell types. RAGE up-regulates the expression of proinflammatory mediators and its own expression via activation of NF-kB. Recent works have proposed a role for RAGE in Parkinson's disease (PD). In this study, we used the multimodal blocker of RAGE FPS-ZM1, which has become available recently, to selectively inhibit RAGE in the substantia nigra (SN) of rats intracranially injected with 6-hydroxydopamine (6-OHDA). FPS-ZM1 (40 μg per rat), injected concomitantly with 6-OHDA (10 μg per rat) into the SN, inhibited the increase in RAGE, activation of ERK1/2, Src and nuclear translocation of NF-kB p65 subunit in the SN. RAGE inhibition blocked glial fibrillary acidic protein and Iba-1 upregulation as well as associated astrocyte and microglia activation. Circulating cytokines in serum and CSF were also decreased by FPS-ZM1 injection. The loss of tyrosine hydroxylase and NeuN-positive neurons was significantly inhibited by RAGE blocking. Finally, FPS-ZM1 attenuated locomotory and exploratory deficits induced by 6-OHDA. Our results demonstrate that RAGE is an essential component in the neuroinflammation and dopaminergic denervation induced by 6-OHDA in the SN. Selective inhibition of RAGE may offer perspectives for therapeutic approaches.
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Affiliation(s)
- Juciano Gasparotto
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | - Camila Tiefensee Ribeiro
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rafael Calixto Bortolin
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Nauana Somensi
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Thallita Kelly Rabelo
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Alice Kunzler
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Natália Cabral Souza
- Instituto de Medicina Tropical, Departamento de Bioquímica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Matheus Augusto de Bittencourt Pasquali
- Unidade Acadêmica de Engenharia de Alimentos, Centro de Tecnologia e Recursos Naturais, Universidade Federal de Campina Grande - UFCG, Campina Grande, Paraíba, Brazil
| | - José Claudio Fonseca Moreira
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Daniel Pens Gelain
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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11
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Evsyukov V, Domanskyi A, Bierhoff H, Gispert S, Mustafa R, Schlaudraff F, Liss B, Parlato R. Genetic mutations linked to Parkinson's disease differentially control nucleolar activity in pre-symptomatic mouse models. Dis Model Mech 2017; 10:633-643. [PMID: 28360124 PMCID: PMC5451170 DOI: 10.1242/dmm.028092] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/28/2017] [Indexed: 12/21/2022] Open
Abstract
Genetic mutations underlying neurodegenerative disorders impair ribosomal DNA (rDNA) transcription suggesting that nucleolar dysfunction could be a novel pathomechanism in polyglutamine diseases and in certain forms of amyotrophic lateral sclerosis/frontotemporal dementia. Here, we investigated nucleolar activity in pre-symptomatic digenic models of Parkinson's disease (PD) that model the multifactorial aetiology of this disease. To this end, we analysed a novel mouse model mildly overexpressing mutant human α-synuclein (hA53T-SNCA) in a PTEN-induced kinase 1 (PINK1/PARK6) knockout background and mutant mice lacking both DJ-1 (also known as PARK7) and PINK1. We showed that overexpressed hA53T-SNCA localizes to the nucleolus. Moreover, these mutants show a progressive reduction of rDNA transcription linked to a reduced mouse lifespan. By contrast, rDNA transcription is preserved in DJ-1/PINK1 double knockout (DKO) mice. mRNA levels of the nucleolar transcription initiation factor 1A (TIF-IA, also known as RRN3) decrease in the substantia nigra of individuals with PD. Because loss of TIF-IA, as a tool to mimic nucleolar stress, increases oxidative stress and because DJ-1 and PINK1 mutations result in higher vulnerability to oxidative stress, we further explored the synergism between these PD-associated genes and impaired nucleolar function. By the conditional ablation of TIF-IA, we blocked ribosomal RNA (rRNA) synthesis in adult dopaminergic neurons in a DJ-1/PINK1 DKO background. However, the early phenotype of these triple knockout mice was similar to those mice exclusively lacking TIF-IA. These data sustain a model in which loss of DJ-1 and PINK1 does not impair nucleolar activity in a pre-symptomatic stage. This is the first study to analyse nucleolar function in digenic PD models. We can conclude that, at least in these models, the nucleolus is not as severely disrupted as previously shown in DA neurons from PD patients and neurotoxin-based PD mouse models. The results also show that the early increase in rDNA transcription and nucleolar integrity may represent specific homeostatic responses in these digenic pre-symptomatic PD models. Summary: Genetic mutations linked to Parkinson's disease lead to stage-specific deregulation of the nucleolus, a major integrator of the cellular stress response.
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Affiliation(s)
- Valentin Evsyukov
- Institute of Anatomy and Medical Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Andrii Domanskyi
- German Cancer Research Center, Molecular Biology of the Cell I, 69120 Heidelberg, Germany.,Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Holger Bierhoff
- German Cancer Research Center, Molecular Biology of the Cell II, 69120 Heidelberg, Germany.,Department of Biochemistry, Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine (CMB), Friedrich Schiller University Jena, 07743 Jena, Germany.,Leibniz-Institute on Aging - Fritz Lipmann Institute (FLI), 07743 Jena, Germany
| | - Suzana Gispert
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Rasem Mustafa
- Institute of Anatomy and Medical Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany.,Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Falk Schlaudraff
- Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Rosanna Parlato
- Institute of Anatomy and Medical Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany .,Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
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Garcia-Esparcia P, Hernández-Ortega K, Koneti A, Gil L, Delgado-Morales R, Castaño E, Carmona M, Ferrer I. Altered machinery of protein synthesis is region- and stage-dependent and is associated with α-synuclein oligomers in Parkinson's disease. Acta Neuropathol Commun 2015; 3:76. [PMID: 26621506 PMCID: PMC4666041 DOI: 10.1186/s40478-015-0257-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/14/2015] [Indexed: 01/17/2023] Open
Abstract
INTRODUCTION Parkinson's disease (PD) is characterized by the accumulation of abnormal α-synuclein in selected regions of the brain following a gradient of severity with disease progression. Whether this is accompanied by globally altered protein synthesis is poorly documented. The present study was carried out in PD stages 1-6 of Braak and middle-aged (MA) individuals without alterations in brain in the substantia nigra, frontal cortex area 8, angular gyrus, precuneus and putamen. RESULTS Reduced mRNA expression of nucleolar proteins nucleolin (NCL), nucleophosmin (NPM1), nucleoplasmin 3 (NPM3) and upstream binding transcription factor (UBF), decreased NPM1 but not NPM3 nucleolar protein immunostaining in remaining neurons; diminished 18S rRNA, 28S rRNA; reduced expression of several mRNAs encoding ribosomal protein (RP) subunits; and altered protein levels of initiation factor eIF3 and elongation factor eEF2 of protein synthesis was found in the substantia nigra in PD along with disease progression. Although many of these changes can be related to neuron loss in the substantia nigra, selective alteration of certain factors indicates variable degree of vulnerability of mRNAs, rRNAs and proteins in degenerating sustantia nigra. NPM1 mRNA and 18S rRNA was increased in the frontal cortex area 8 at stage 5-6; modifications were less marked and region-dependent in the angular gyrus and precuneus. Several RPs were abnormally regulated in the frontal cortex area 8 and precuneus, but only one RP in the angular gyrus, in PD. Altered levels of eIF3 and eIF1, and decrease eEF1A and eEF2 protein levels were observed in the frontal cortex in PD. No modifications were found in the putamen at any time of the study except transient modifications in 28S rRNA and only one RP mRNA at stages 5-6. These observations further indicate marked region-dependent and stage-dependent alterations in the cerebral cortex in PD. Altered solubility and α-synuclein oligomer formation, assessed in total homogenate fractions blotted with anti-α-synuclein oligomer-specific antibody, was demonstrated in the substantia nigra and frontal cortex, but not in the putamen, in PD. Dramatic increase in α-synuclein oligomers was also seen in fluorescent-activated cell sorter (FACS)-isolated nuclei in the frontal cortex in PD. CONCLUSIONS Altered machinery of protein synthesis is altered in the substantia nigra and cerebral cortex in PD being the frontal cortex area 8 more affected than the angular gyrus and precuneus; in contrast, pathways of protein synthesis are apparently preserved in the putamen. This is associated with the presence of α-synuclein oligomeric species in total homogenates; substantia nigra and frontal cortex are enriched, albeit with different band patterns, in α-synuclein oligomeric species, whereas α-synuclein oligomers are not detected in the putamen.
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Affiliation(s)
- Paula Garcia-Esparcia
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Karina Hernández-Ortega
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Anusha Koneti
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Laura Gil
- Department of Genetics, Medical School, Alfonso X el Sabio University, Villanueva de la Cañada, Madrid, Spain
| | - Raul Delgado-Morales
- Cancer Epigenetics and Biology Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Ester Castaño
- Biology-Bellvitge Unit, Scientific and Technological Centers-University of Barcelona (CCiTUB), Hospitalet de Llobregat, Barcelona, Spain
| | - Margarita Carmona
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain.
- Institute of Neuropathology, Service of Pathologic Anatomy, Bellvitge University Hospital, carrer Feixa Llarga s/n, 08907, Hospitalet de Llobregat, Spain.
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Katagiri N, Kuroda T, Kishimoto H, Hayashi Y, Kumazawa T, Kimura K. The nucleolar protein nucleophosmin is essential for autophagy induced by inhibiting Pol I transcription. Sci Rep 2015; 5:8903. [PMID: 25754892 PMCID: PMC4354046 DOI: 10.1038/srep08903] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 02/10/2015] [Indexed: 12/19/2022] Open
Abstract
Various cellular stresses activate autophagy, which is involved in lysosomal degradation of cytoplasmic materials for maintaining nutrient homeostasis and eliminating harmful components. Here, we show that RNA polymerase I (Pol I) transcription inhibition induces nucleolar disruption and autophagy. Treatment with autophagy inhibitors or siRNA specific for autophagy-related (ATG) proteins inhibited autophagy but not nucleolar disruption induced by Pol I transcription inhibition, which suggested that nucleolar disruption was upstream of autophagy. Furthermore, treatment with siRNA specific for nucleolar protein nucleophosmin (NPM) inhibited this type of autophagy. This showed that NPM was involved in autophagy when the nucleolus was disrupted by Pol I inhibition. In contrast, NPM was not required for canonical autophagy induced by nutrient starvation, as it was not accompanied by nucleolar disruption. Thus, our results revealed that, in addition to canonical autophagy, there may be NPM-dependent autophagy associated with nucleolar disruption.
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Affiliation(s)
- Naohiro Katagiri
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
| | - Takao Kuroda
- Center of Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
| | - Hiroyuki Kishimoto
- 1] Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan [2] Center of Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
| | - Yuki Hayashi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
| | - Takuya Kumazawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
| | - Keiji Kimura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennnoudai, Tsukuba 305-8577, Japan
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Parlato R, Bierhoff H. Role of nucleolar dysfunction in neurodegenerative disorders: a game of genes? AIMS MOLECULAR SCIENCE 2015. [DOI: 10.3934/molsci.2015.3.211] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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15
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Dave KD, De Silva S, Sheth NP, Ramboz S, Beck MJ, Quang C, Switzer RC, Ahmad SO, Sunkin SM, Walker D, Cui X, Fisher DA, McCoy AM, Gamber K, Ding X, Goldberg MS, Benkovic SA, Haupt M, Baptista MA, Fiske BK, Sherer TB, Frasier MA. Phenotypic characterization of recessive gene knockout rat models of Parkinson's disease. Neurobiol Dis 2014; 70:190-203. [DOI: 10.1016/j.nbd.2014.06.009] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 05/30/2014] [Accepted: 06/13/2014] [Indexed: 11/25/2022] Open
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Differential effects of intrastriatal 6-hydroxydopamine on cell number and morphology in midbrain dopaminergic subregions of the rat. Brain Res 2014; 1574:113-9. [PMID: 24924804 DOI: 10.1016/j.brainres.2014.05.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 05/05/2014] [Accepted: 05/30/2014] [Indexed: 11/21/2022]
Abstract
The midbrain dopaminergic perikarya are differentially affected in Parkinson׳s disease (PD). This study compared the effects of a partial unilateral intrastriatal 6-hydroxydopamine (6-OHDA) lesion model of PD on the number, morphology, and nucleolar volume of dopaminergic cells in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA), and retrorubral field (RRF). Adult, male rats (n=10) underwent unilateral intrastriatal infusion of 6-OHDA (12.5μg). Lesions were verified by amphetamine-stimulated rotation 7 days post-infusion. Rats were euthanized 14 days after treatment with 6-OHDA and brains were stained with a tyrosine hydroxylase-silver nucleolar (TH-AgNOR) stain. Dopaminergic cell number and morphology in the lesioned and intact hemispheres were quantified using stereological methods. The magnitude of decrease in planimetric volume, neuronal number, cell density, and neuronal volume resulting from 6-OHDA lesion differed between regions, with the SNpc exhibiting the greatest loss of neurons (46%), but the smallest decrease in neuronal volume (13%). The lesion also resulted in a decrease in nucleolar volume that was similar in all three regions (22-26%). These findings indicate that intrastriatal 6-OHDA lesion differentially affects dopaminergic neurons in the SNpc, VTA, and RRF; however, the resulting changes in nucleolar morphology suggest a similar cellular response to the toxin in all three cell populations.
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Parlato R, Liss B. How Parkinson's disease meets nucleolar stress. Biochim Biophys Acta Mol Basis Dis 2014; 1842:791-7. [PMID: 24412806 DOI: 10.1016/j.bbadis.2013.12.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/13/2013] [Accepted: 12/31/2013] [Indexed: 12/19/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder. Although the causes of PD are still not understood, aging is a predisposing factor and metabolic stress seems to be a common trigger. Interestingly, the response to stress conditions and quality control mechanisms is impaired in PD, as well as in other neurodegenerative disorders. Downregulation of rRNA transcription is one major strategy to maintain cellular homeostasis under stress conditions, as it limits energy consumption in disadvantageous circumstances. Altered rRNA transcription and disruption of nucleolar integrity are associated with neurodegenerative disorders, and with aging. Nucleolar stress can be triggered by genetic and epigenetic factors, and by specific signaling mechanisms, that are altered in neurodegenerative disorders. The consequences of neuronal nucleolar stress seem to depend on p53 function, the mammalian target of rapamycin (mTOR) activity and deregulation of protein translation. In this review, we will summarize findings identifying an emerging role of nucleolar stress for the onset and progression of in particular PD. Emphasis is given to similarities in molecular causes and consequences of nucleolar stress in other neurodegenerative disorders. The mechanisms by which nucleolar stress participates in PD could help identify novel risk factors, and develop new therapeutic strategies to slow down the progressive loss of neurons in neurodegenerative diseases. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.
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Affiliation(s)
- Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Ulm, Germany; Institute of Anatomy and Cell Biology, Department of Medical Biology, University of Heidelberg, Heidelberg, Germany; Dept. of Molecular Biology of the Cell I, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany.
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
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Valencia M, Chavez M, Artieda J, Bolam JP, Mena-Segovia J. Abnormal functional connectivity between motor cortex and pedunculopontine nucleus following chronic dopamine depletion. J Neurophysiol 2013; 111:434-40. [PMID: 24174651 DOI: 10.1152/jn.00555.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The activity of the basal ganglia is altered in Parkinson's disease (PD) as a consequence of the degeneration of dopamine neurons in the substantia nigra pars compacta. This results in aberrant discharge patterns and expression of exaggerated oscillatory activity across the basal ganglia circuit. Altered activity has also been reported in some of the targets of the basal ganglia, including the pedunculopontine nucleus (PPN), possibly due to its close interconnectivity with most regions of the basal ganglia. However, the nature of the involvement of the PPN in the pathophysiology of PD has not been fully elucidated. Here, we recorded local field potentials in the motor cortex and the PPN in the 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD under urethane anesthesia. By means of linear and nonlinear statistics, we analyzed the synchrony between the motor cortex and the PPN and the delay in the interaction between these two structures. We observed the presence of coherent activity between the cortex and the PPN in low (5-15 Hz)- and high (25-35 Hz)-frequency bands during episodes of cortical activation. In each case, the cortex led the PPN. Dopamine depletion strengthened the interaction of the low-frequency activities by increasing the coherence specifically in the theta and alpha ranges and reduced the delay of the interaction in the gamma band. Our data show that cortical inputs play a determinant role in leading the coherent activity with the PPN and support the involvement of the PPN in the pathophysiology of PD.
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Affiliation(s)
- Miguel Valencia
- Neurophysiology Laboratory, Neuroscience Area, CIMA, Universidad de Navarra, Pamplona, Spain
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