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Ortiz GG, Ramírez-Jirano J, Arizaga RL, Delgado-Lara DLC, Torres-Sánchez ED. Frontotemporal-TDP and LATE Neurocognitive Disorders: A Pathophysiological and Genetic Approach. Brain Sci 2023; 13:1474. [PMID: 37891841 PMCID: PMC10605418 DOI: 10.3390/brainsci13101474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/07/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Frontotemporal lobar degeneration (FTLD) belongs to a heterogeneous group of highly complex neurodegenerative diseases and represents the second cause of presenile dementia in individuals under 65. Frontotemporal-TDP is a subgroup of frontotemporal dementia characterized by the aggregation of abnormal protein deposits, predominantly transactive response DNA-binding protein 43 (TDP-43), in the frontal and temporal brain regions. These deposits lead to progressive degeneration of neurons resulting in cognitive and behavioral impairments. Limbic age-related encephalopathy (LATE) pertains to age-related cognitive decline primarily affecting the limbic system, which is crucial for memory, emotions, and learning. However, distinct, emerging research suggests a potential overlap in pathogenic processes, with some cases of limbic encephalopathy displaying TDP-43 pathology. Genetic factors play a pivotal role in both disorders. Mutations in various genes, such as progranulin (GRN) and chromosome 9 open reading frame 72 (C9orf72), have been identified as causative in frontotemporal-TDP. Similarly, specific genetic variants have been associated with an increased risk of developing LATE. Understanding these genetic links provides crucial insights into disease mechanisms and the potential for targeted therapies.
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Affiliation(s)
- Genaro Gabriel Ortiz
- Department of Philosophical and Methodological Disciplines, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico;
- Postgraduate Gerontology Program, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico
| | - Javier Ramírez-Jirano
- Neurosciences Division, Western Biomedical Research Center, Mexican Social Security Institute, IMSS, Guadalajara 44340, Jalisco, Mexico;
| | - Raul L. Arizaga
- Public Health Department, School of Medicine, University of Buenos Aires, Buenos Aires C1121ABG, Argentina;
| | - Daniela L. C. Delgado-Lara
- Department of Philosophical and Methodological Disciplines, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico;
- Departamento Académico de Formación Universitaria, Ciencias de la Salud, Universidad Autónoma de Guadalajara, Zapopan 45129, Jalisco, Mexico
| | - Erandis D. Torres-Sánchez
- Department of Medical and Life Sciences, University Center of la Cienega, University of Guadalajara, Ocotlan 47820, Jalisco, Mexico
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2
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Reviewing the Potential Links between Viral Infections and TDP-43 Proteinopathies. Int J Mol Sci 2023; 24:ijms24021581. [PMID: 36675095 PMCID: PMC9867397 DOI: 10.3390/ijms24021581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 01/15/2023] Open
Abstract
Transactive response DNA binding protein 43 kDa (TDP-43) was discovered in 2001 as a cellular factor capable to inhibit HIV-1 gene expression. Successively, it was brought to new life as the most prevalent RNA-binding protein involved in several neurological disorders, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Despite the fact that these two research areas could be considered very distant from each other, in recent years an increasing number of publications pointed out the existence of a potentially important connection. Indeed, the ability of TDP-43 to act as an important regulator of all aspects of RNA metabolism makes this protein also a critical factor during expression of viral RNAs. Here, we summarize all recent observations regarding the involvement of TDP-43 in viral entry, replication and latency in several viruses that include enteroviruses (EVs), Theiler's murine encephalomyelitis virus (TMEV), human immunodeficiency virus (HIV), human endogenous retroviruses (HERVs), hepatitis B virus (HBV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), West Nile virus (WNV), and herpes simplex virus-2 (HSV). In particular, in this work, we aimed to highlight the presence of similarities with the most commonly studied TDP-43 related neuronal dysfunctions.
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3
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Scotter EL, Cao MC, Jansson D, Rustenhoven J, Smyth LCD, Aalderink MC, Siemens A, Fan V, Wu J, Mee EW, Faull RLM, Dragunow M. The amyotrophic lateral sclerosis-linked protein TDP-43 regulates interleukin-6 cytokine production by human brain pericytes. Mol Cell Neurosci 2022; 123:103768. [PMID: 36038081 DOI: 10.1016/j.mcn.2022.103768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 08/02/2022] [Accepted: 08/12/2022] [Indexed: 12/30/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal movement disorder involving degeneration of motor neurons through dysfunction of the RNA-binding protein TDP-43. Pericytes, the perivascular cells of the blood-brain, blood-spinal cord, and blood-CSF barriers also degenerate in ALS. Indeed, pericytes are among the earliest cell types to show gene expression changes in pre-symptomatic animal models of ALS. This suggests that pericyte degeneration precedes neurodegeneration and may involve pericyte cell-autonomous TDP-43 dysfunction. Here we determined the effect of TDP-43 dysfunction in human brain pericytes on interleukin 6 (IL-6), a critical secreted inflammatory mediator reported to be regulated by TDP 43. Primary human brain pericytes were cultured from biopsy tissue from epilepsy surgeries and TDP-43 was silenced using siRNA. TDP-43 silencing of pericytes stimulated with pro-inflammatory cytokines, interleukin-1β or tumour necrosis factor alpha, robustly suppressed the induction of IL-6 transcript and protein. IL-6 regulation by TDP-43 did not involve the assembly of TDP-43 nuclear splicing bodies, and did not occur via altered splicing of IL6. Instead, transcriptome-wide analysis by RNA-Sequencing identified a poison exon in the IL6 destabilising factor HNRNPD (AUF1) as a splicing target of TDP-43. Our data support a model whereby TDP-43 silencing favours destabilisation of IL6 mRNA, via enhanced AU-rich element-mediated decay by HNRNP/AUF1. This suggests that cell-autonomous deficits in TDP-43 function in human brain pericytes would suppress their production of IL-6. Given the importance of the blood-brain and blood-spinal cord barriers in maintaining motor neuron health, TDP-43 in human brain pericytes may represent a cellular target for ALS therapeutics.
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Affiliation(s)
- Emma L Scotter
- Centre for Brain Research, University of Auckland, New Zealand; School of Biological Sciences, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Maize C Cao
- Centre for Brain Research, University of Auckland, New Zealand; School of Biological Sciences, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Deidre Jansson
- Centre for Brain Research, University of Auckland, New Zealand; School of Biological Sciences, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Justin Rustenhoven
- Centre for Brain Research, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Leon C D Smyth
- Centre for Brain Research, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Miranda C Aalderink
- Centre for Brain Research, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Andrew Siemens
- Centre for Brain Research, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
| | - Vicky Fan
- Bioinformatics Institute, University of Auckland, Auckland, New Zealand.
| | - Jane Wu
- Centre for Brain Research, University of Auckland, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, New Zealand.
| | - Edward W Mee
- Department of Neurosurgery, Auckland City Hospital, Auckland, New Zealand.
| | - Richard L M Faull
- Centre for Brain Research, University of Auckland, New Zealand; Department of Anatomy and Medical Imaging, University of Auckland, New Zealand.
| | - Mike Dragunow
- Centre for Brain Research, University of Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, New Zealand.
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4
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Lee TA, Han H, Polash A, Cho SK, Lee JW, Ra EA, Lee E, Park A, Kang S, Choi JL, Kim JH, Lee JE, Min KW, Yang SW, Hafner M, Lee I, Yoon JH, Lee S, Park B. The nucleolus is the site for inflammatory RNA decay during infection. Nat Commun 2022; 13:5203. [PMID: 36057640 PMCID: PMC9440930 DOI: 10.1038/s41467-022-32856-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 08/16/2022] [Indexed: 11/12/2022] Open
Abstract
Inflammatory cytokines are key signaling molecules that can promote an immune response, thus their RNA turnover must be tightly controlled during infection. Most studies investigate the RNA decay pathways in the cytosol or nucleoplasm but never focused on the nucleolus. Although this organelle has well-studied roles in ribosome biogenesis and cellular stress sensing, the mechanism of RNA decay within the nucleolus is not completely understood. Here, we report that the nucleolus is an essential site of inflammatory pre-mRNA instability during infection. RNA-sequencing analysis reveals that not only do inflammatory genes have higher intronic read densities compared with non-inflammatory genes, but their pre-mRNAs are highly enriched in nucleoli during infection. Notably, nucleolin (NCL) acts as a guide factor for recruiting cytosine or uracil (C/U)-rich sequence-containing inflammatory pre-mRNAs and the Rrp6-exosome complex to the nucleolus through a physical interaction, thereby enabling targeted RNA delivery to Rrp6-exosomes and subsequent degradation. Consequently, Ncl depletion causes aberrant hyperinflammation, resulting in a severe lethality in response to LPS. Importantly, the dynamics of NCL post-translational modifications determine its functional activity in phases of LPS. This process represents a nucleolus-dependent pathway for maintaining inflammatory gene expression integrity and immunological homeostasis during infection. The nucleolus is the traditional site for ribosomal RNA biogenesis. Here, the authors find that the nucleolus is a site of inflammatory pre-mRNA turnover and elucidated how immune homeostasis can be maintained by controlling inflammatory gene expression.
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Affiliation(s)
- Taeyun A Lee
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Heonjong Han
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea.,Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea.,Division of Tumor Immunology, Research Institute, National Cancer Center, Goyang, South Korea
| | - Ahsan Polash
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, National Institutes of Health, Bethesda, MD, USA
| | - Seok Keun Cho
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Ji Won Lee
- Department of Biology, College of Natural Sciences, Gangneung-Wonju National University, Gangneung, South Korea
| | - Eun A Ra
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Eunhye Lee
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Areum Park
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Sujin Kang
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Junhee L Choi
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Ji Hyun Kim
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea.,Samsung Genome Institute (SGI), Samsung Medical Center, Seoul, South Korea
| | - Kyung-Won Min
- Department of Biology, College of Natural Sciences, Gangneung-Wonju National University, Gangneung, South Korea.,Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Seong Wook Yang
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Markus Hafner
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute for Arthritis and Musculoskeletal and Skin Disease, National Institutes of Health, Bethesda, MD, USA
| | - Insuk Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Je-Hyun Yoon
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA.
| | - Sungwook Lee
- Division of Tumor Immunology, Research Institute, National Cancer Center, Goyang, South Korea.
| | - Boyoun Park
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea.
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5
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Guillemin A, Kumar A, Wencker M, Ricci EP. Shaping the Innate Immune Response Through Post-Transcriptional Regulation of Gene Expression Mediated by RNA-Binding Proteins. Front Immunol 2022; 12:796012. [PMID: 35087521 PMCID: PMC8787094 DOI: 10.3389/fimmu.2021.796012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/13/2021] [Indexed: 12/20/2022] Open
Abstract
Innate immunity is the frontline of defense against infections and tissue damage. It is a fast and semi-specific response involving a myriad of processes essential for protecting the organism. These reactions promote the clearance of danger by activating, among others, an inflammatory response, the complement cascade and by recruiting the adaptive immunity. Any disequilibrium in this functional balance can lead to either inflammation-mediated tissue damage or defense inefficiency. A dynamic and coordinated gene expression program lies at the heart of the innate immune response. This expression program varies depending on the cell-type and the specific danger signal encountered by the cell and involves multiple layers of regulation. While these are achieved mainly via transcriptional control of gene expression, numerous post-transcriptional regulatory pathways involving RNA-binding proteins (RBPs) and other effectors play a critical role in its fine-tuning. Alternative splicing, translational control and mRNA stability have been shown to be tightly regulated during the innate immune response and participate in modulating gene expression in a global or gene specific manner. More recently, microRNAs assisting RBPs and post-transcriptional modification of RNA bases are also emerging as essential players of the innate immune process. In this review, we highlight the numerous roles played by specific RNA-binding effectors in mediating post-transcriptional control of gene expression to shape innate immunity.
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Affiliation(s)
- Anissa Guillemin
- LBMC, Laboratoire de Biologie et Modelisation de la Cellule, Université de Lyon, ENS de Lyon, Universite Claude Bernard Lyon 1, CNRS, UMR 5239, INSERM, U1293, Lyon, France
| | - Anuj Kumar
- CRCL, Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR 5286, Lyon, France
| | - Mélanie Wencker
- LBMC, Laboratoire de Biologie et Modelisation de la Cellule, Université de Lyon, ENS de Lyon, Universite Claude Bernard Lyon 1, CNRS, UMR 5239, INSERM, U1293, Lyon, France
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, ENS de Lyon, CNRS, UMR 5308, INSERM, Lyon, France
| | - Emiliano P. Ricci
- LBMC, Laboratoire de Biologie et Modelisation de la Cellule, Université de Lyon, ENS de Lyon, Universite Claude Bernard Lyon 1, CNRS, UMR 5239, INSERM, U1293, Lyon, France
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6
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Zhao MJ, Yao X, Wei P, Zhao C, Cheng M, Zhang D, Xue W, He WT, Xue W, Zuo X, Jiang LL, Luo Z, Song J, Shu WJ, Yuan HY, Liang Y, Sun H, Zhou Y, Zhou Y, Zheng L, Hu HY, Wang J, Du HN. O-GlcNAcylation of TDP-43 suppresses proteinopathies and promotes TDP-43's mRNA splicing activity. EMBO Rep 2021; 22:e51649. [PMID: 33855783 DOI: 10.15252/embr.202051649] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
Pathological TDP-43 aggregation is characteristic of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP); however, how TDP-43 aggregation and function are regulated remain poorly understood. Here, we show that O-GlcNAc transferase OGT-mediated O-GlcNAcylation of TDP-43 suppresses ALS-associated proteinopathies and promotes TDP-43's splicing function. Biochemical and cell-based assays indicate that OGT's catalytic activity suppresses TDP-43 aggregation and hyperphosphorylation, whereas abolishment of TDP-43 O-GlcNAcylation impairs its RNA splicing activity. We further show that TDP-43 mutations in the O-GlcNAcylation sites improve locomotion defects of larvae and adult flies and extend adult life spans, following TDP-43 overexpression in Drosophila motor neurons. We finally demonstrate that O-GlcNAcylation of TDP-43 promotes proper splicing of many mRNAs, including STMN2, which is required for normal axonal outgrowth and regeneration. Our findings suggest that O-GlcNAcylation might be a target for the treatment of TDP-43-linked pathogenesis.
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Affiliation(s)
- Meng-Jie Zhao
- Department of Thoracic Surgery, Renmin Hospital of Wuhan University, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiao Yao
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Ping Wei
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Chen Zhao
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Meng Cheng
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Dong Zhang
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Wen Xue
- Clinical Research Institute, Affiliated Nanhua Hospital, University of South China, Hengyang, China.,Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai, China
| | - Wen-Tian He
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Weili Xue
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Xinxin Zuo
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Zhiyuan Luo
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute at School of Medicine, Wuhan University, Wuhan, China
| | - Jiaqi Song
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Wen-Jie Shu
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Han-Ye Yuan
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Yi Liang
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Hui Sun
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Yan Zhou
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute at School of Medicine, Wuhan University, Wuhan, China
| | - Yu Zhou
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Ling Zheng
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Jiwu Wang
- Clinical Research Institute, Affiliated Nanhua Hospital, University of South China, Hengyang, China.,Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hai-Ning Du
- Hubei Key Laboratory of Cell Homeostasis, RNA Institute, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
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7
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Buratti E. Trends in Understanding the Pathological Roles of TDP-43 and FUS Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1281:243-267. [PMID: 33433879 DOI: 10.1007/978-3-030-51140-1_15] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Following the discovery of TDP-43 and FUS involvement in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD), the major challenge in the field has been to understand their physiological functions, both in normal and disease conditions. The hope is that this knowledge will improve our understanding of disease and lead to the development of effective therapeutic options. Initially, the focus has been directed at characterizing the role of these proteins in the control of RNA metabolism, because the main function of TDP-43 and FUS is to bind coding and noncoding RNAs to regulate their life cycle within cells. As a result, we now have an in-depth picture of the alterations that occur in RNA metabolism following their aggregation in various ALS/FTLD models and, to a somewhat lesser extent, in patients' brains. In parallel, progress has been made with regard to understanding how aggregation of these proteins occurs in neurons, how it can spread in different brain regions, and how these changes affect various metabolic cellular pathways to result in neuronal death. The aim of this chapter will be to provide a general overview of the trending topics in TDP-43 and FUS investigations and to highlight what might represent the most promising avenues of research in the years to come.
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Affiliation(s)
- Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy.
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8
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Buratti E. Targeting TDP-43 proteinopathy with drugs and drug-like small molecules. Br J Pharmacol 2020; 178:1298-1315. [PMID: 32469420 DOI: 10.1111/bph.15148] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023] Open
Abstract
Following the discovery of the involvement of the ribonucleoprotein TDP-43 in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), a major research focus has been to develop treatments that can prevent or alleviate these disease conditions. One pharmacological approach has been to use TDP-43-based disease models to test small molecules and drugs already known to have some therapeutic effect in a variety of neurodegenerative conditions. In parallel, various disease models have been used to perform high-throughput screens of drugs and small compound libraries. The aim of this review will be to provide a general overview of the compounds that have been described to alter pathological characteristics of TDP-43. These include expression levels, cytoplasmic mis-localization, post-translational modifications, cleavage, stress granule recruitment and aggregation. In parallel, this review will also address the use of compounds that modify the autophagic/proteasome systems that are known to target TDP-43 misfolding and aggregation. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.6/issuetoc.
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Affiliation(s)
- Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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9
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Abstract
BACKGROUND Emerging evidence suggests retroviruses play a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). Specifically, activation of ancient viral genes embedded in the human genome is theorized to lead to motor neuron degeneration. We explore whether connections exist between ALS and retroviruses through protein interaction networks (PIN) and pathway analysis, and consider the potential roles in drug target discovery. Protein database and pathway/network analytical software including Ingenuity Pathway BioProfiler, STRING, and CytoScape were utilized to identify overlapping protein interaction networks and extract core cluster (s) of retroviruses and ALS. RESULTS Topological and statistical analysis of the ALS-PIN and retrovirus-PIN identified a shared, essential protein network and a core cluster with significant connections with both networks. The identified core cluster has three interleukin molecules IL10, Il-6 and IL-1B, a central apoptosis regulator TP53, and several major transcription regulators including MAPK1, ANXA5, SQSTM1, SREBF2, and FADD. Pathway enrichment analysis showed that this core cluster is associated with the glucocorticoid receptor singling and neuroinflammation signaling pathways. For confirmation purposes, we applied the same methodology to the West Nile and Polio virus, which demonstrated trivial connectivity with ALS, supporting the unique connection between ALS and retroviruses. CONCLUSIONS Bioinformatics analysis provides evidence to support pathological links between ALS and retroviral activation. The neuroinflammation and apoptotic regulation pathways are specifically implicated. The continuation and further analysis of large scale genome studies may prove useful in exploring genes important in retroviral activation and ALS, which may help discover new drug targets.
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10
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Saroz Y, Kho DT, Glass M, Graham ES, Grimsey NL. Cannabinoid Receptor 2 (CB 2) Signals via G-alpha-s and Induces IL-6 and IL-10 Cytokine Secretion in Human Primary Leukocytes. ACS Pharmacol Transl Sci 2019; 2:414-428. [PMID: 32259074 DOI: 10.1021/acsptsci.9b00049] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Indexed: 12/11/2022]
Abstract
Cannabinoid receptor 2 (CB2) is a promising therapeutic target for immunological modulation. There is, however, a deficit of knowledge regarding CB2 signaling and function in human primary immunocompetent cells. We applied an experimental paradigm which closely models the in situ state of human primary leukocytes (PBMC; peripheral blood mononuclear cells) to characterize activation of a number of signaling pathways in response to a CB2-selective ligand (HU308). We observed a "lag" phase of unchanged cAMP concentration prior to development of classically expected Gαi-mediated inhibition of cAMP synthesis. Application of G protein inhibitors revealed that this apparent lag was a result of counteraction of Gαi effects by concurrent Gαs activation. Monitoring downstream signaling events showed that activation of p38 was mediated by Gαi, whereas ERK1/2 and Akt phosphorylation were mediated by Gαi-coupled βγ. Activation of CREB integrated multiple components; Gαs and βγ mediated ∼85% of the response, while ∼15% was attributed to Gαi. Responses to HU308 had an important functional outcome-secretion of interleukins 6 (IL-6) and 10 (IL-10). IL-2, IL-4, IL-12, IL-13, IL-17A, MIP-1α, and TNF-α were unaffected. IL-6/IL-10 induction had a similar G protein coupling profile to CREB activation. All response potencies were consistent with that expected for HU308 acting via CB2. Additionally, signaling and functional effects were completely blocked by a CB2-selective inverse agonist, giving additional evidence for CB2 involvement. This work expands the current paradigm regarding cannabinoid immunomodulation and reinforces the potential utility of CB2 ligands as immunomodulatory therapeutics.
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Affiliation(s)
- Yurii Saroz
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Dan T Kho
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, Division of Health Sciences, University of Otago, Dunedin, 9016, New Zealand
| | - Euan Scott Graham
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Natasha Lillia Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, Centre for Brain Research, Faculty of Medical and Health Sciences, and Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
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11
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Schaub A, Glasmacher E. Splicing in immune cells-mechanistic insights and emerging topics. Int Immunol 2018; 29:173-181. [PMID: 28498981 PMCID: PMC5890895 DOI: 10.1093/intimm/dxx026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 04/27/2017] [Indexed: 11/26/2022] Open
Abstract
Differential splicing of mRNAs not only enables regulation of gene expression levels, but also ensures a high degree of gene-product diversity. The extent to which splicing of mRNAs is utilized as a mechanism in immune cells has become evident within the last few years. Still, only a few of these mechanisms have been well studied. In this review, we discuss some of the best-understood mechanisms, for instance the differential splicing of CD45 in T cells, as well as immunoglobulin genes in B cells. Beyond that we provide general mechanistic insights on how, when and where this process takes place and discuss the current knowledge regarding these topics in immune cells. We also highlight some of the reported links to immune-related diseases, genome-wide sequencing studies that revealed thousands of differentially spliced transcripts, as well as splicing studies on immune cells that remain mechanistically not fully understood. We thereby display potential emerging topics for future studies centered on splicing mechanisms in immune cells.
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Affiliation(s)
- Annalisa Schaub
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Elke Glasmacher
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
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12
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Regulation of inflammatory responses by dynamic subcellular localization of RNA-binding protein Arid5a. Proc Natl Acad Sci U S A 2018; 115:E1214-E1220. [PMID: 29358370 PMCID: PMC5819453 DOI: 10.1073/pnas.1719921115] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Adenine-thymine (AT)-rich interactive domain 5a (Arid5a) is an RNA-binding protein found in the cytoplasm and nucleus of normally growing cells. Although Arid5a is known to play an important role in immune regulation, whether and how Arid5a subcellular localization impacts immune regulation has remained unclear. In this study, we generated Arid5a transgenic (TG) mice to address this question. While ectopic Arid5a overexpression did not affect expression of inflammatory cytokines under unstimulated conditions, significantly higher levels of inflammatory cytokines, such as IL-6, were produced in response to lipopolysaccharide (LPS) stimulation. Consistent with this, TG mice were more sensitive to LPS treatment than wild-type mice. We also found that Arid5a is imported into the nucleus via a classical importin-α/β1-mediated pathway. On stimulation, nuclear Arid5a levels were decreased, while there was a concomitant increase in cytoplasmic Arid5a. Arid5a is associated with up-frameshift protein 1, and its nuclear export is regulated by a nuclear export receptor, chromosomal region maintenance 1. Taken together, these data indicate that Arid5a is a dynamic protein that translocates to the cytoplasm from the nucleus so as to properly exert its dual function in mRNA stabilization and transcriptional regulation during inflammatory conditions.
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13
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Wiesner D, Tar L, Linkus B, Chandrasekar A, Olde Heuvel F, Dupuis L, Tsao W, Wong PC, Ludolph A, Roselli F. Reversible induction of TDP-43 granules in cortical neurons after traumatic injury. Exp Neurol 2017; 299:15-25. [PMID: 28941811 DOI: 10.1016/j.expneurol.2017.09.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/18/2017] [Accepted: 09/19/2017] [Indexed: 12/12/2022]
Abstract
Traumatic brain injury (TBI) has been proposed as a risk factor for neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). To determine whether TBI might trigger or exacerbate ALS-relevant pathology, we delivered a mild stab-wound injury to the motor cortex of three different ALS mouse models expressing mutations in SOD1, TDP-43 or FUS and scrutinized the effects on the formation of phospho-TDP-43 (pTDP-43) cytoplasmic granules. Stab-injury induced the formation of cytoplasmic TDP-43 granules in wt animals, peaking at 3dpi; a much larger response was seen in mutant TDP-43 mice, whose response peaked at 7dpi. The pTDP-43 granules did not colocalize with the stress markers TIAR-1 and FUS but colocalized with FMRP (35%) and with p62 (65%), suggesting their involvement in transport granules and their clearance by autophagy. A similar, albeit smaller effect, was seen in mutant FUS mice. In the SOD1G93A mouse model, neither increase in pTDP-43 granules nor in SOD1 aggregates were detected. In all cases, pTDP-43 granules were cleared and the number of pTDP-43-positive neurons returned to baseline by 40dpi. Neither injury-related neuronal loss nor motor performance or survival was significantly different in transgenic mice receiving injury vs sham mice. Thus, trauma can trigger ALS-related TDP-43 pathology, the extent of which is modulated by ALS-related mutations. However, the pathological findings prove reversible and do not affect disease progression and neuronal vulnerability.
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Affiliation(s)
- Diana Wiesner
- Dept. of Neurology, University of Ulm School of Medicine, Ulm, Germany
| | - Lilla Tar
- Dept. of Neurology, University of Ulm School of Medicine, Ulm, Germany
| | - Birgit Linkus
- Dept. of Neurology, University of Ulm School of Medicine, Ulm, Germany
| | | | | | - Luc Dupuis
- Inserm U1118, Mécanismes centraux et périphétiques de la neurodégénérescence, Strasbourg, France; Université de Strasbourg, Faculté de Médecine, Strasbourg, France
| | - William Tsao
- Dept. of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Cellular and Molecular Medicine Program, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Philip C Wong
- Dept. of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Cellular and Molecular Medicine Program, Johns Hopkins University School of Medicine, Baltimore, United States; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Albert Ludolph
- Dept. of Neurology, University of Ulm School of Medicine, Ulm, Germany
| | - Francesco Roselli
- Dept. of Neurology, University of Ulm School of Medicine, Ulm, Germany; Dept. of Anatomy and Cell Biology, University of Ulm School of Medicine, Germany.
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14
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Heyburn L, Moussa CEH. TDP-43 in the spectrum of MND-FTLD pathologies. Mol Cell Neurosci 2017; 83:46-54. [PMID: 28687523 DOI: 10.1016/j.mcn.2017.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/28/2017] [Accepted: 07/04/2017] [Indexed: 12/12/2022] Open
Abstract
The relationship between RNA-binding proteins, particularly TAR DNA binding protein 43 (TDP-43), and neurodegeneration is an important area of research. TDP-43 is involved in so many cellular processes that perturbation of protein homeostasis can lead to countless downstream effects. Understanding what leads to this disease-related protein imbalance and the resulting cellular and molecular effects will help to develop targets for disease intervention, whether it be prevention of protein accumulation, or addressing a secondary effect of protein accumulation. Here we review the current literature of TDP-43 and TDP-43 pathologies, the effects of TDP-43 overexpression and disruption of synaptic proteins through its binding of messenger RNA, leading to synaptic dysfunction. This review highlights some of the still-limited knowledge of the protein TDP-43 and how it can contribute to disease.
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Affiliation(s)
- Lanier Heyburn
- Department of Neurology, Translational Neurotherapeutics Program, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA; Department of Pathology, Georgetown University Medical Center, Washington D.C., USA 20007.
| | - Charbel E-H Moussa
- Department of Neurology, Translational Neurotherapeutics Program, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA
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15
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Ratti A, Buratti E. Physiological functions and pathobiology of TDP-43 and FUS/TLS proteins. J Neurochem 2016; 138 Suppl 1:95-111. [PMID: 27015757 DOI: 10.1111/jnc.13625] [Citation(s) in RCA: 245] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/19/2016] [Accepted: 03/22/2016] [Indexed: 12/12/2022]
Abstract
The multiple roles played by RNA binding proteins in neurodegeneration have become apparent following the discovery of TAR DNA binding protein 43 kDa (TDP-43) and fused in sarcoma/translocated in liposarcoma (FUS/TLS) involvement in amyotrophic lateral sclerosis and frontotemporal lobar dementia. In these two diseases, the majority of patients display the presence of aggregated forms of one of these proteins in their brains. The study of their functional properties currently represents a very promising target for developing the effective therapeutic options that are still lacking. This aim, however, must be preceded by an accurate evaluation of TDP-43 and FUS/TLS biological functions, both in physiological and disease conditions. Recent findings have uncovered several aspects of RNA metabolism that can be affected by misregulation of these two proteins. Progress has also been made in starting to understand how the aggregation of these proteins occurs and spreads from cell to cell. The aim of this review will be to provide a general overview of TDP-43 and FUS/TLS proteins and to highlight their physiological functions. At present, the emerging picture is that TDP-43 and FUS/TLS control several aspects of an mRNA's life, but they can also participate in DNA repair processes and in non-coding RNA metabolism. Although their regulatory activities are similar, they regulate mainly distinct RNA targets and show different pathogenetic mechanisms in amyotrophic lateral sclerosis/frontotemporal lobar dementia diseases. The identification of key events in these processes represents today the best chance of finding targetable options for therapeutic approaches that might actually make a difference at the clinical level. The two major RNA Binding Proteins involved in Amyotrophic Lateral Sclerosisi and Frontotemporal Dementia are TDP-43 and FUST/TLS. Both proteins are involved in regulating all aspects of RNA and RNA life cycle within neurons, from transcription, processing, and transport/stability to the formation of cytoplasmic and nuclear stress granules. For this reason, the aberrant aggregation of these factors during disease can impair multiple RNA metabolic pathways and eventually lead to neuronal death/inactivation. The purpose of this review is to provide an up-to-date perspective on what we know about this issue at the molecular level. This article is part of the Frontotemporal Dementia special issue.
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Affiliation(s)
- Antonia Ratti
- Department of Pathophysiology and Transplantation, 'Dino Ferrari' Center - Università degli Studi di Milano, Milan, Italy.,Department of Neurology and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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16
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Henry FE, Sugino K, Tozer A, Branco T, Sternson SM. Cell type-specific transcriptomics of hypothalamic energy-sensing neuron responses to weight-loss. eLife 2015; 4. [PMID: 26329458 PMCID: PMC4595745 DOI: 10.7554/elife.09800] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/02/2015] [Indexed: 12/13/2022] Open
Abstract
Molecular and cellular processes in neurons are critical for sensing and responding to energy deficit states, such as during weight-loss. Agouti related protein (AGRP)-expressing neurons are a key hypothalamic population that is activated during energy deficit and increases appetite and weight-gain. Cell type-specific transcriptomics can be used to identify pathways that counteract weight-loss, and here we report high-quality gene expression profiles of AGRP neurons from well-fed and food-deprived young adult mice. For comparison, we also analyzed Proopiomelanocortin (POMC)-expressing neurons, an intermingled population that suppresses appetite and body weight. We find that AGRP neurons are considerably more sensitive to energy deficit than POMC neurons. Furthermore, we identify cell type-specific pathways involving endoplasmic reticulum-stress, circadian signaling, ion channels, neuropeptides, and receptors. Combined with methods to validate and manipulate these pathways, this resource greatly expands molecular insight into neuronal regulation of body weight, and may be useful for devising therapeutic strategies for obesity and eating disorders. DOI:http://dx.doi.org/10.7554/eLife.09800.001 Humans and other animals must get adequate nutrition in order to survive. As a result, the body has several systems that work side by side to maintain a healthy body weight and ensure that enough food gets eaten to provide the energy that the body needs. Problems with these systems can contribute towards obesity and other eating disorders. Certain types of cells in the brain play important roles in controlling weight and appetite, although the genes and cellular mechanisms that underlie these abilities are not well understood. When an animal is deprived of food, so-called AGRP neurons produce molecules that increase appetite and make it easier to gain weight. These neurons also go through structural changes and increase their electrical activity during weight loss. Another group of cells, called the POMC neurons, becomes less active when an animal is deprived of energy. Using a technique called cell type-specific transcriptomics, Henry, Sugino et al. have now revealed that the expression of hundreds of genes in AGRP and POMC neurons changes depending on whether mice are well fed or food deprived. Food deprivation also affects more genes in AGRP neurons than has been seen in other types of brain cell, and the AGRP neurons are also more sensitive to a change in food intake than POMC neurons. In the future, this gene expression data and knowledge of the pathways affected by the genes could help researchers to develop new treatments for obesity and other disorders that affect appetite. Henry, Sugino et al. then mapped how these changes in gene expression trigger molecular “pathways” in the neurons that alter how the cells work. These affect many parts of the cells, including ion channels, transcription factors, receptors, and secreted proteins. In addition, food deprivation activated pathways in AGRP neurons that protect the cells from damage and death caused by elevated neuron activity and also triggered signaling pathways that increase body weight. In the future, this gene expression data and knowledge of the pathways affected by the genes could help researchers to develop new treatments for obesity and other disorders that affect appetite. DOI:http://dx.doi.org/10.7554/eLife.09800.002
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Affiliation(s)
- Fredrick E Henry
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ken Sugino
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Adam Tozer
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Tiago Branco
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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Complex Inflammation mRNA-Related Response in ALS Is Region Dependent. Neural Plast 2015; 2015:573784. [PMID: 26301107 PMCID: PMC4537753 DOI: 10.1155/2015/573784] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/04/2015] [Accepted: 06/25/2015] [Indexed: 12/13/2022] Open
Abstract
Inflammatory changes are analyzed in the anterior spinal cord and frontal cortex area 8 in typical spinal-predominant ALS cases. Increased numbers of astrocytes and activated microglia are found in the anterior horn of the spinal cord and pyramidal tracts. Significant increased expression of TLR7, CTSS, and CTSC mRNA and a trend to increased expression of IL10RA, TGFB1, and TGFB2 are found in the anterior lumbar spinal cord in ALS cases compared to control cases, whereas C1QTNF7 and TNFRSF1A mRNA expression levels are significantly decreased. IL6 is significantly upregulated and IL1B shows a nonsignificant increased expression in frontal cortex area 8 in ALS cases. IL-6 immunoreactivity is found in scattered monocyte-derived macrophages/microglia and TNF-α in a few cells of unknown origin in ALS cases. Increased expression and abnormal distribution of IL-1β occurred in motor neurons of the lumbar spinal cord in ALS. Strong IL-10 immunoreactivity colocalizes with TDP-43-positive inclusions in motor neurons in ALS cases. The present observations show a complex participation of cytokines and mediators of the inflammatory response in ALS consistent with increased proinflammatory cytokines and sequestration of anti-inflammatory IL-10 in affected neurons.
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18
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Hyperproduction of IL-6 caused by aberrant TDP-43 overexpression in high-fat diet-induced obese mice. FEBS Lett 2015; 589:1825-31. [PMID: 26037142 DOI: 10.1016/j.febslet.2015.05.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/25/2015] [Accepted: 05/09/2015] [Indexed: 02/06/2023]
Abstract
Inclusion of Tat-activating regulatory DNA-binding protein-43 (TDP-43) due to hyperphosphorylation or hyperubiquitination is a cause of neurodegenerative disease. Cellular TDP-43 expression is tightly controlled through a negative feedback loop involving its mRNA. Recently, we reported that the TDP-43-mediated sub-nuclear body is an essential site of interleukin-6 (IL-6) pre-mRNA processing. Here we show that mice fed on a high-fat diet exhibit increased TDP-43 expression in the liver and adipose tissue with a prominent increase in IL-6. TDP-43 depletion in vivo reduces IL-6 production in the liver. Overexpression or depletion of TDP-43 in pre-adipose and adipose cells causes reciprocal alteration of IL-6 expression and RNA processing. Our findings provide evidence for a link between homeostasis of TDP-43 expression and the risk of developing obesity.
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Abstract
The degeneration of motor neurons in amyotrophic lateral sclerosis (ALS) inevitably causes paralysis and death within a matter of years. Mounting genetic and functional evidence suggest that abnormalities in RNA processing and metabolism underlie motor neuron loss in sporadic and familial ALS. Abnormal localization and aggregation of essential RNA-binding proteins are fundamental pathological features of sporadic ALS, and mutations in genes encoding RNA processing enzymes cause familial disease. Also, expansion mutations occurring in the noncoding region of C9orf72-the most common cause of inherited ALS-result in nuclear RNA foci, underscoring the link between abnormal RNA metabolism and neurodegeneration in ALS. This review summarizes the current understanding of RNA dysfunction in ALS, and builds upon this knowledge base to identify converging mechanisms of neurodegeneration in ALS. Potential targets for therapy development are highlighted, with particular emphasis on early and conserved pathways that lead to motor neuron loss in ALS.
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Affiliation(s)
- Sami J Barmada
- Department of Neurology, University of Michigan, 109 Zina Pitcher Place, 5015 Biomedical Sciences Research Building, SSPC 2200, Ann Arbor, MI, 48109, USA,
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