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Zhang L, Wang W, Chen T, Cui J, Li X, Liu A, Liu R, Fang L, Jiang J, Yang L, Wu D, Ying S. SAMHD1 dysfunction induces IL-34 expression via NF-κB p65 in neuronal SH-SY5Y cells. Mol Immunol 2024; 168:1-9. [PMID: 38367301 DOI: 10.1016/j.molimm.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/19/2024]
Abstract
Dysfunctional mutations in SAMHD1 cause Aicardi-Goutières Syndrome, an autoinflammatory encephalopathy with elevated interferon-α levels in the cerebrospinal fluid. Whether loss of function mutations in SAMHD1 trigger the expression of other cytokines apart from type I interferons in Aicardi-Goutières Syndrome is largely unclear. This study aimed to explore whether SAMHD1 dysfunction regulated the expression of IL-34, a key cytokine controlling the development and maintenance of microglia, in SH-SY5Y neural cells. We found that downregulation of SAMHD1 in SH-SY5Y cells resulted in the upregulation of IL-34 expression. The protein and mRNA levels of NF-κB p65, the transactivating subunit of a transcription factor NF-κB, were also upregulated in SAMHD1-knockdown SH-SY5Y cells. It was further found SAMHD1 knockdown in SH-SY5Y cells induced an upregulation of IL-34 expression through the canonical NF-κB-dependent pathway in which NF-κB p65, IKKα/β and the NF-κB inhibitor IκBα were phosphorylated. Moreover, knockdown of SAMHD1 in SH-SY5Y cells led to the translocation of NF-κB p65 into the nucleus and promoted NF-κB transcriptional activity. In conclusion, we found SAMHD1 dysfunction induced IL-34 expression via NF-κB p65 in neuronal SH-SY5Y cells. This finding could lay the foundation for exploring the role of IL-34-targeting microglia in the pathogenesis of Aicardi-Goutières Syndrome.
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Affiliation(s)
- Ling Zhang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Wenjing Wang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China; First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Ting Chen
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Jiuhao Cui
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Xin Li
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China; First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Anran Liu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China; First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Rumeng Liu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China; First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui Province 230032, China
| | - Liwei Fang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China; Department of Paediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province 230022, China
| | - Junhong Jiang
- Department of Paediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province 230022, China
| | - Li Yang
- Department of Paediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province 230022, China
| | - De Wu
- Department of Paediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province 230022, China
| | - Songcheng Ying
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province 230032, China.
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2
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Gavazzi F, Gonzalez CD, Arnold K, Swantkowski M, Charlton L, Modesti N, Dar AA, Vanderver A, Bennett M, Adang LA. Nucleotide metabolism, leukodystrophies, and CNS pathology. J Inherit Metab Dis 2024:10.1002/jimd.12721. [PMID: 38421058 PMCID: PMC11358362 DOI: 10.1002/jimd.12721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024]
Abstract
The balance between a protective and a destructive immune response can be precarious, as exemplified by inborn errors in nucleotide metabolism. This class of inherited disorders, which mimics infection, can result in systemic injury and severe neurologic outcomes. The most common of these disorders is Aicardi Goutières syndrome (AGS). AGS results in a phenotype similar to "TORCH" infections (Toxoplasma gondii, Other [Zika virus (ZIKV), human immunodeficiency virus (HIV)], Rubella virus, human Cytomegalovirus [HCMV], and Herpesviruses), but with sustained inflammation and ongoing potential for complications. AGS was first described in the early 1980s as familial clusters of "TORCH" infections, with severe neurology impairment, microcephaly, and basal ganglia calcifications (Aicardi & Goutières, Ann Neurol, 1984;15:49-54) and was associated with chronic cerebrospinal fluid (CSF) lymphocytosis and elevated type I interferon levels (Goutières et al., Ann Neurol, 1998;44:900-907). Since its first description, the clinical spectrum of AGS has dramatically expanded from the initial cohorts of children with severe impairment to including individuals with average intelligence and mild spastic paraparesis. This broad spectrum of potential clinical manifestations can result in a delayed diagnosis, which families cite as a major stressor. Additionally, a timely diagnosis is increasingly critical with emerging therapies targeting the interferon signaling pathway. Despite the many gains in understanding about AGS, there are still many gaps in our understanding of the cell-type drivers of pathology and characterization of modifying variables that influence clinical outcomes and achievement of timely diagnosis.
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Affiliation(s)
- Francesco Gavazzi
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | - Kaley Arnold
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Meghan Swantkowski
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lauren Charlton
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Nicholson Modesti
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Asif A. Dar
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Adeline Vanderver
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariko Bennett
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Laura A. Adang
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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3
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Rapti G. Regulation of axon pathfinding by astroglia across genetic model organisms. Front Cell Neurosci 2023; 17:1241957. [PMID: 37941606 PMCID: PMC10628440 DOI: 10.3389/fncel.2023.1241957] [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: 06/18/2023] [Accepted: 09/07/2023] [Indexed: 11/10/2023] Open
Abstract
Glia and neurons are intimately associated throughout bilaterian nervous systems, and were early proposed to interact for patterning circuit assembly. The investigations of circuit formation progressed from early hypotheses of intermediate guideposts and a "glia blueprint", to recent genetic and cell manipulations, and visualizations in vivo. An array of molecular factors are implicated in axon pathfinding but their number appears small relatively to circuit complexity. Comprehending this circuit complexity requires to identify unknown factors and dissect molecular topographies. Glia contribute to both aspects and certain studies provide molecular and functional insights into these contributions. Here, I survey glial roles in guiding axon navigation in vivo, emphasizing analogies, differences and open questions across major genetic models. I highlight studies pioneering the topic, and dissect recent findings that further advance our current molecular understanding. Circuits of the vertebrate forebrain, visual system and neural tube in zebrafish, mouse and chick, the Drosophila ventral cord and the C. elegans brain-like neuropil emerge as major contexts to study glial cell functions in axon navigation. I present astroglial cell types in these models, and their molecular and cellular interactions that drive axon guidance. I underline shared principles across models, conceptual or technical complications, and open questions that await investigation. Glia of the radial-astrocyte lineage, emerge as regulators of axon pathfinding, often employing common molecular factors across models. Yet this survey also highlights different involvements of glia in embryonic navigation or pioneer axon pathfinding, and unknowns in the molecular underpinnings of glial cell functions. Future cellular and molecular investigations should complete the comprehensive view of glial roles in circuit assembly.
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Affiliation(s)
- Georgia Rapti
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Rome, Italy
- Interdisciplinary Center of Neurosciences, Heidelberg University, Heidelberg, Germany
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4
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Liu A, Ying S. Aicardi-Goutières syndrome: A monogenic type I interferonopathy. Scand J Immunol 2023; 98:e13314. [PMID: 37515439 DOI: 10.1111/sji.13314] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/26/2023] [Accepted: 07/16/2023] [Indexed: 07/30/2023]
Abstract
Aicardi-Goutières syndrome (AGS) is a rare monogenic autoimmune disease that primarily affects the brains of children patients. Its main clinical features include encephalatrophy, basal ganglia calcification, leukoencephalopathy, lymphocytosis and increased interferon-α (IFN-α) levels in the patient's cerebrospinal fluid (CSF) and serum. AGS may be caused by mutations in any one of nine genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1, IFIH1, LSM11 and RNU7-1) that result in accumulation of self-nucleic acids in the cytoplasm or aberrant sensing of self-nucleic acids. This triggers overproduction of type I interferons (IFNs) and subsequently causes AGS, the prototype of type I interferonopathies. This review describes the discovery history of AGS with various genotypes and provides the latest knowledge of clinical manifestations and causative genes of AGS. The relationship between AGS and type I interferonopathy and potential therapeutic methods for AGS are also discussed in this review.
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Affiliation(s)
- Anran Liu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, China
| | - Songcheng Ying
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
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Xu H, Pu J, Lin S, Hu R, Yao J, Li X. Preimplantation genetic testing for Aicardi-Goutières syndrome induced by novel compound heterozygous mutations of TREX1: an unaffected live birth. Mol Cytogenet 2023; 16:9. [PMID: 37277873 DOI: 10.1186/s13039-023-00641-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/25/2023] [Indexed: 06/07/2023] Open
Abstract
BACKGROUND Aicardi-Goutières syndrome (AGS) is a rare, autosomal recessive, hereditary neurodegenerative disorder. It is characterized mainly by early onset progressive encephalopathy, concomitant with an increase in interferon-α levels in the cerebrospinal fluid. Preimplantation genetic testing (PGT) is a procedure that could be used to choose unaffected embryos for transfer after analysis of biopsied cells, which prevents at-risk couples from facing the risk of pregnancy termination. METHODS Trio-based whole exome sequencing, karyotyping and chromosomal microarray analysis were used to determine the pathogenic mutations for the family. To block the inheritance of the disease, multiple annealing and looping-based amplification cycles was used for whole genome amplification of the biopsied trophectoderm cells. Sanger sequencing and next-generation sequencing (NGS)-based single nucleotide polymorphism (SNP) haplotyping were used to detect the state of the gene mutations. Copy number variation (CNV) analysis was also carried out to prevent embryonic chromosomal abnormalities. Prenatal diagnosis was preformed to verify the PGT outcomes. RESULTS A novel compound heterozygous mutation in TREX1 gene was found in the proband causing AGS. A total of 3 blastocysts formed after intracytoplasmic sperm injection were biopsied. After genetic analyses, an embryo harbored a heterozygous mutation in TREX1 and without CNV was transferred. A healthy baby was born at 38th weeks and prenatal diagnosis results confirmed the accuracy of PGT. CONCLUSIONS In this study, we identified two novel pathogenic mutations in TREX1, which has not been previously reported. Our study extends the mutation spectrum of TREX1 gene and contributes to the molecular diagnosis as well as genetic counseling for AGS. Our results demonstrated that combining NGS-based SNP haplotyping for PGT-M with invasive prenatal diagnosis is an effective approach to block the transmission of AGS and could be applied to prevent other monogenic diseases.
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Affiliation(s)
- Huiling Xu
- Department of Reproductive Medicine, Southern Medical University Affiliated Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, China
| | - Jiajie Pu
- Department of Bioinformatics, 01life Institute, Shenzhen, 518000, Guangdong, China
| | - Suiling Lin
- Department of Reproductive Medicine, Southern Medical University Affiliated Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, China
| | - Rui Hu
- Department of Reproductive Medicine, Southern Medical University Affiliated Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, China
| | - Jilong Yao
- Department of Reproductive Medicine, Southern Medical University Affiliated Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, China
| | - Xuemei Li
- Department of Reproductive Medicine, Southern Medical University Affiliated Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, China.
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6
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Fang L, Ying S, Xu X, Wu D. TREX1 cytosolic DNA degradation correlates with autoimmune disease and cancer immunity. Clin Exp Immunol 2023; 211:193-207. [PMID: 36745566 PMCID: PMC10038326 DOI: 10.1093/cei/uxad017] [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: 10/24/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 02/07/2023] Open
Abstract
The N-terminal domain of Three Prime Repair Exonuclease 1 (TREX1) is catalytically active and can degrade dsDNA or ssDNA in the cytosol, whereas the C-terminal domain is primarily involved in protein localization. TREX1 deficiency induces cytosolic DNA accumulation as well as activation of the cGAS-STING-IFN signaling pathway, which results in tissue inflammation and autoimmune diseases. Furthermore, TREX1 expression in cancer immunity can be adaptively regulated to promote tumor proliferation, making it a promising therapeutic target.
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Affiliation(s)
- Liwei Fang
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Songcheng Ying
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Xi Xu
- Department of Plastic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - De Wu
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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7
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Vezzani A, Ravizza T, Bedner P, Aronica E, Steinhäuser C, Boison D. Astrocytes in the initiation and progression of epilepsy. Nat Rev Neurol 2022; 18:707-722. [PMID: 36280704 PMCID: PMC10368155 DOI: 10.1038/s41582-022-00727-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2022] [Indexed: 11/09/2022]
Abstract
Epilepsy affects ~65 million people worldwide. First-line treatment options include >20 antiseizure medications, but seizure control is not achieved in approximately one-third of patients. Antiseizure medications act primarily on neurons and can provide symptomatic control of seizures, but do not alter the onset and progression of epilepsy and can cause serious adverse effects. Therefore, medications with new cellular and molecular targets and mechanisms of action are needed. Accumulating evidence indicates that astrocytes are crucial to the pathophysiological mechanisms of epilepsy, raising the possibility that these cells could be novel therapeutic targets. In this Review, we discuss how dysregulation of key astrocyte functions - gliotransmission, cell metabolism and immune function - contribute to the development and progression of hyperexcitability in epilepsy. We consider strategies to mitigate astrocyte dysfunction in each of these areas, and provide an overview of how astrocyte activation states can be monitored in vivo not only to assess their contribution to disease but also to identify markers of disease processes and treatment effects. Improved understanding of the roles of astrocytes in epilepsy has the potential to lead to novel therapies to prevent the initiation and progression of epilepsy.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy.
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA
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8
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Hussain H, Djurin T, Rodriguez J, Daneelian L, Sundi S, Fadel A, Saadoon Z. Transactivation Response DNA-Binding Protein of 43 (TDP-43) and Glial Cell Roles in Neurological Disorders. Cureus 2022; 14:e30639. [DOI: 10.7759/cureus.30639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2022] [Indexed: 11/07/2022] Open
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9
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Nowacki JC, Fields AM, Fu MM. Emerging cellular themes in leukodystrophies. Front Cell Dev Biol 2022; 10:902261. [PMID: 36003149 PMCID: PMC9393611 DOI: 10.3389/fcell.2022.902261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.
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10
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Adang LA, Gavazzi F, D'Aiello R, Isaacs D, Bronner N, Arici ZS, Flores Z, Jan A, Scher C, Sherbini O, Behrens EM, Goldbach-Mansky R, Olson TS, Lambert MP, Sullivan KE, Teachey DT, Witmer C, Vanderver A, Shults J. Hematologic abnormalities in Aicardi Goutières Syndrome. Mol Genet Metab 2022; 136:324-329. [PMID: 35786528 PMCID: PMC9357135 DOI: 10.1016/j.ymgme.2022.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Because of the broad clinical spectrum, heritable autoinflammatory diseases present a management and therapeutic challenge. The most common genetic interferonopathy, Aicardi Goutières Syndrome (AGS), is associated with early onset neurologic disability and systemic inflammation. The chronic inflammation of AGS is the result of dysregulation of interferon (IFN) expression by one of nine genes within converging pathways. While each AGS subtype shares common features, distinct patterns of severity and potential for systemic complications amongst the genotypes are emerging. Multilineage cytopenias are a potentially serious, but poorly understood, complication of AGS. As immunomodulatory treatment options are developed, it is important to characterize the role of the disease versus treatment in hematologic abnormalities. This will allow for better understanding and management of cytopenia. METHODS In total, 142 individuals with molecularly-confirmed AGS were included. Information on genotype, demographics, and all available hematologic laboratory values were collected from existing medical records. As part of a clinical trial, a subset of this cohort (n = 52) were treated with a janus kinase inhibitor (baricitinib), and both pre- and post-treatment values were included. Abnormal values were graded based on Common Terminology Criteria for Adverse Events (CTCAE v5.0), supplemented with grading definitions for thrombocytosis, and were compared across genotypes and baricitinib exposure. RESULTS In total, 11,184 laboratory values were collected over a median of 2.54 years per subject (range 0-22.68 years). To reduce bias from repeated sampling within a limited timeframe, laboratory results were restricted to the most abnormal value within a month (n = 8485). The most common abnormalities were anemia (noted in 24% of subjects prior to baricitinib exposure), thrombocytopenia (9%), and neutropenia (30%). Neutropenia was most common in the SAMHD1 cohort and increased with baricitinib exposure (38/69 measurements on baricitinib versus 14/121 while not on baricitinib). Having an abnormality prior to treatment was associated with having an abnormality on treatment for neutropenia and thrombocytopenia. CONCLUSION By collecting available laboratory data throughout the lifespan, we were able to identify novel patterns of hematologic abnormalities in AGS. We found that AGS results in multilineage cytopenias not limited to the neonatal period. Neutropenia, anemia, and thrombocytopenia were common. Moderate-severe graded events of neutropenia, anemia, and leukopenia were more common on baricitinib, but rarely of clinical consequence. Based on these results, we would recommend careful monitoring of hematologic parameters of children affected by AGS throughout the lifespan, especially while on therapy, and consideration of AGS as a potential differential diagnosis in children with neurologic impairment of unclear etiology with hematologic abnormalities. Trial registration ClinicalTrials.gov Identifier: NCT01724580 ClinicalTrials.gov Identifier: NCT03921554.
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Affiliation(s)
- Laura A Adang
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Francesco Gavazzi
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Russell D'Aiello
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - David Isaacs
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nowa Bronner
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Zehra Serap Arici
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Zaida Flores
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Amanda Jan
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Carly Scher
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Omar Sherbini
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Edward M Behrens
- Division of Rheumatology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Raphaela Goldbach-Mansky
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Timothy S Olson
- Division of Oncology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michele P Lambert
- Division of Hematology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kathleen E Sullivan
- Division of Immunology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - David T Teachey
- Division of Oncology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Char Witmer
- Division of Hematology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Adeline Vanderver
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Justine Shults
- Department of Statistics, University of Pennsylvania, Philadelphia, PA, Philadelphia, PA, USA
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11
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Giordano AMS, Luciani M, Gatto F, Abou Alezz M, Beghè C, Della Volpe L, Migliara A, Valsoni S, Genua M, Dzieciatkowska M, Frati G, Tahraoui-Bories J, Giliani SC, Orcesi S, Fazzi E, Ostuni R, D'Alessandro A, Di Micco R, Merelli I, Lombardo A, Reijns MAM, Gromak N, Gritti A, Kajaste-Rudnitski A. DNA damage contributes to neurotoxic inflammation in Aicardi-Goutières syndrome astrocytes. J Exp Med 2022; 219:213058. [PMID: 35262626 PMCID: PMC8916121 DOI: 10.1084/jem.20211121] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 11/22/2021] [Accepted: 01/24/2022] [Indexed: 01/09/2023] Open
Abstract
Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-Goutières syndrome (AGS), but the mechanisms triggering disease in the human central nervous system (CNS) remain elusive. Here, we generated human models of AGS using genetically modified and patient-derived pluripotent stem cells harboring TREX1 or RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades impacting multiple CNS cell subsets analyzed at the single-cell level. We identify accumulating DNA damage, with elevated R-loop and micronuclei formation, as a driver of STING- and NLRP3-related inflammatory responses leading to the secretion of neurotoxic mediators. Importantly, pharmacological inhibition of proapoptotic or inflammatory cascades in AGS astrocytes prevents neurotoxicity without apparent impact on their increased type I IFN responses. Together, our work identifies DNA damage as a major driver of neurotoxic inflammation in AGS astrocytes, suggests a role for AGS gene products in R-loop homeostasis, and identifies common denominators of disease that can be targeted to prevent astrocyte-mediated neurotoxicity in AGS.
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Affiliation(s)
- Anna Maria Sole Giordano
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
| | - Marco Luciani
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
| | - Francesca Gatto
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Monah Abou Alezz
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Chiara Beghè
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Lucrezia Della Volpe
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
| | - Alessandro Migliara
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy.,Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
| | - Sara Valsoni
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Marco Genua
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Monika Dzieciatkowska
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Giacomo Frati
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Julie Tahraoui-Bories
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Clara Giliani
- Department of Molecular and Translational Medicine, "Angelo Nocivelli" Institute for Molecular Medicine, University of Brescia, Azienda Socio Sanitaria Territoriale Spedali Civili, Brescia, Italy
| | - Simona Orcesi
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,Child Neurology and Psychiatry Unit, Istituto di Ricovero e Cura a Carattere Scientifico Mondino Foundation, Pavia, Italy
| | - Elisa Fazzi
- Unit of Child Neurology and Psychiatry, Brescia, Department of Clinical and Experimental Sciences, University of Brescia, Azienda Socio Sanitaria Territoriale Spedali Civili, Brescia, Italy
| | - Renato Ostuni
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Raffaella Di Micco
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Ivan Merelli
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Angelo Lombardo
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Martin A M Reijns
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Angela Gritti
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
| | - Anna Kajaste-Rudnitski
- San Raffaele Telethon Institute for Gene Therapy, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute, Milan, Italy
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12
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Wang Q, Du J, Hua S, Zhao K. TREX1 Plays Multiple Roles in Human Diseases. Cell Immunol 2022; 375:104527. [DOI: 10.1016/j.cellimm.2022.104527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/12/2022] [Accepted: 04/10/2022] [Indexed: 11/15/2022]
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13
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Zarekiani P, Nogueira Pinto H, Hol EM, Bugiani M, de Vries HE. The neurovascular unit in leukodystrophies: towards solving the puzzle. Fluids Barriers CNS 2022; 19:18. [PMID: 35227276 PMCID: PMC8887016 DOI: 10.1186/s12987-022-00316-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/11/2022] [Indexed: 12/11/2022] Open
Abstract
The neurovascular unit (NVU) is a highly organized multicellular system localized in the brain, formed by neuronal, glial (astrocytes, oligodendrocytes, and microglia) and vascular (endothelial cells and pericytes) cells. The blood-brain barrier, a complex and dynamic endothelial cell barrier in the brain microvasculature that separates the blood from the brain parenchyma, is a component of the NVU. In a variety of neurological disorders, including Alzheimer's disease, multiple sclerosis, and stroke, dysfunctions of the NVU occurs. There is, however, a lack of knowledge regarding the NVU function in leukodystrophies, which are rare monogenic disorders that primarily affect the white matter. Since leukodystrophies are rare diseases, human brain tissue availability is scarce and representative animal models that significantly recapitulate the disease are difficult to develop. The introduction of human induced pluripotent stem cells (hiPSC) now makes it possible to surpass these limitations while maintaining the ability to work in a biologically relevant human context and safeguarding the genetic background of the patient. This review aims to provide further insights into the NVU functioning in leukodystrophies, with a special focus on iPSC-derived models that can be used to dissect neurovascular pathophysiology in these diseases.
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Affiliation(s)
- Parand Zarekiani
- Department of Pathology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, de Boelelaan 1117, Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Henrique Nogueira Pinto
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, de Boelelaan 1117, Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands.
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14
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Bugiani M, Plug BC, Man JHK, Breur M, van der Knaap MS. Heterogeneity of white matter astrocytes in the human brain. Acta Neuropathol 2022; 143:159-177. [PMID: 34878591 DOI: 10.1007/s00401-021-02391-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/17/2021] [Accepted: 11/28/2021] [Indexed: 12/12/2022]
Abstract
Astrocytes regulate central nervous system development, maintain its homeostasis and orchestrate repair upon injury. Emerging evidence support functional specialization of astroglia, both between and within brain regions. Different subtypes of gray matter astrocytes have been identified, yet molecular and functional diversity of white matter astrocytes remains largely unexplored. Nonetheless, their important and diverse roles in maintaining white matter integrity and function are well recognized. Compelling evidence indicate that impairment of normal astrocytic function and their response to injury contribute to a wide variety of diseases, including white matter disorders. In this review, we highlight our current understanding of astrocyte heterogeneity in the white matter of the mammalian brain and how an interplay between developmental origins and local environmental cues contribute to astroglial diversification. In addition, we discuss whether, and if so, how, heterogeneous astrocytes could contribute to white matter function in health and disease and focus on the sparse human research data available. We highlight four leukodystrophies primarily due to astrocytic dysfunction, the so-called astrocytopathies. Insight into the role of astroglial heterogeneity in both healthy and diseased white matter may provide new avenues for therapies aimed at promoting repair and restoring normal white matter function.
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15
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Lanciotti A, Brignone MS, Macioce P, Visentin S, Ambrosini E. Human iPSC-Derived Astrocytes: A Powerful Tool to Study Primary Astrocyte Dysfunction in the Pathogenesis of Rare Leukodystrophies. Int J Mol Sci 2021; 23:ijms23010274. [PMID: 35008700 PMCID: PMC8745131 DOI: 10.3390/ijms23010274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are very versatile cells, endowed with multitasking capacities to ensure brain homeostasis maintenance from brain development to adult life. It has become increasingly evident that astrocytes play a central role in many central nervous system pathologies, not only as regulators of defensive responses against brain insults but also as primary culprits of the disease onset and progression. This is particularly evident in some rare leukodystrophies (LDs) where white matter/myelin deterioration is due to primary astrocyte dysfunctions. Understanding the molecular defects causing these LDs may help clarify astrocyte contribution to myelin formation/maintenance and favor the identification of possible therapeutic targets for LDs and other CNS demyelinating diseases. To date, the pathogenic mechanisms of these LDs are poorly known due to the rarity of the pathological tissue and the failure of the animal models to fully recapitulate the human diseases. Thus, the development of human induced pluripotent stem cells (hiPSC) from patient fibroblasts and their differentiation into astrocytes is a promising approach to overcome these issues. In this review, we discuss the primary role of astrocytes in LD pathogenesis, the experimental models currently available and the advantages, future evolutions, perspectives, and limitations of hiPSC to study pathologies implying astrocyte dysfunctions.
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Affiliation(s)
- Angela Lanciotti
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Maria Stefania Brignone
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Pompeo Macioce
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
| | - Sergio Visentin
- National Center for Research and Preclinical and Clinical Evaluation of Drugs, Istituto Superiore di Sanità, 00169 Rome, Italy;
| | - Elena Ambrosini
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy; (A.L.); (M.S.B.); (P.M.)
- Correspondence: ; Tel.: +39-064-990-2037
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16
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Aditi, Downing SM, Schreiner PA, Kwak YD, Li Y, Shaw TI, Russell HR, McKinnon PJ. Genome instability independent of type I interferon signaling drives neuropathology caused by impaired ribonucleotide excision repair. Neuron 2021; 109:3962-3979.e6. [PMID: 34655526 PMCID: PMC8686690 DOI: 10.1016/j.neuron.2021.09.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/22/2021] [Accepted: 09/20/2021] [Indexed: 12/25/2022]
Abstract
Aicardi-Goutières syndrome (AGS) is a monogenic type I interferonopathy characterized by neurodevelopmental defects and upregulation of type I interferon signaling and neuroinflammation. Mutations in genes that function in nucleic acid metabolism, including RNASEH2, are linked to AGS. Ribonuclease H2 (RNASEH2) is a genome surveillance factor critical for DNA integrity by removing ribonucleotides incorporated into replicating DNA. Here we show that RNASEH2 is necessary for neurogenesis and to avoid activation of interferon-responsive genes and neuroinflammation. Cerebellar defects after RNASEH2B inactivation are rescued by p53 but not cGAS deletion, suggesting that DNA damage signaling, not neuroinflammation, accounts for neuropathology. Coincident inactivation of Atm and Rnaseh2 further affected cerebellar development causing ataxia, which was dependent upon aberrant activation of non-homologous end-joining (NHEJ). The loss of ATM also markedly exacerbates cGAS-dependent type I interferon signaling. Thus, DNA damage-dependent signaling rather than type I interferon signaling underlies neurodegeneration in this class of neurodevelopmental/neuroinflammatory disease.
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Affiliation(s)
- Aditi
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Susanna M Downing
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Patrick A Schreiner
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Young Don Kwak
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yang Li
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | - Helen R Russell
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Peter J McKinnon
- Center for Pediatric Neurological Disease Research, St. Jude Pediatric Translational Neuroscience Initiative, Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA; St. Jude Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
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17
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Xu L, Zhang C, Yin H, Gong S, Wu N, Ren Z, Zhang Y. RNA modifications act as regulators of cell death. RNA Biol 2021; 18:2183-2193. [PMID: 34313542 PMCID: PMC8632120 DOI: 10.1080/15476286.2021.1925460] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 12/14/2022] Open
Abstract
Currently, more than one hundred types of RNA modifications have been found, and many of these modifications are reversible and dynamically regulated. RNA modifications can regulate RNA stability and translation and are thus involved in multiple biological activities. Recently, RNA modifications have been shown to have important roles in the regulation of cell death. Cell death is a critical process that maintains tissue homoeostasis and is regulated by multiple pathways in response to specific stimuli. In this review, we summarize the current understanding of the roles of RNA modifications in cell death mediation and discuss the prospects of such research.Abbreviations: m6A, N6-Methyladenosine; m6Am, N6,2'-O-Dimethyladenosine; m1A, N1-Methyladenosine; m5C, 5-Methylcytosine; hm5C, 5-Hydroxymethylcytosine; Ψ, pseudouridine; A-to-I, adenosine-to- inosine; hnRNPs, heterogeneous nuclear ribonucleoproteins; MOMP, mitochondrial outer membrane permeabilization; DD, death domain; DISC, death-inducing signalling complex; DED, death effector domain; FADD, FAS-associated protein with the death domain; TRADD, TNF receptor-associated protein with death domain; CMA, chaperone- mediated autophagy; PE, phosphatidylethanolamine; AD, alzheimer's disease; AML, acute myeloid leukaemia; miR, microRNA; 6-OHDA, 6-hydroxydopamine hydrochloride; R-2HG, R-2-hydroxyglutarate; IRES, internal ribosome entry site; BMSCs, bone-derived mesenchymal stem cells; NPCs, nucleus pulposus cells; HsCG, human chorionic gonadotropin; snoRNAs, small nucleolar RNAs; ER, endoplasmic reticulum; lncRNAs, long noncoding RNAs; TNM, tumour-node-metastasis.
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Affiliation(s)
- Lei Xu
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Chong Zhang
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Hang Yin
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Shuai Gong
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Nai Wu
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Zeqiang Ren
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Yi Zhang
- Department of General Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
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18
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Inoue M, Nakahama T, Yamasaki R, Shibuya T, Kim JI, Todo H, Xing Y, Kato Y, Morii E, Kawahara Y. An Aicardi-Goutières Syndrome-Causative Point Mutation in Adar1 Gene Invokes Multiorgan Inflammation and Late-Onset Encephalopathy in Mice. THE JOURNAL OF IMMUNOLOGY 2021; 207:3016-3027. [PMID: 34772697 DOI: 10.4049/jimmunol.2100526] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/13/2021] [Indexed: 12/23/2022]
Abstract
Aicardi-Goutières syndrome (AGS) is a congenital inflammatory disorder accompanied by overactivated type I IFN signaling and encephalopathy with leukodystrophy and intracranial calcification. To date, none of the mouse models carrying an AGS-causative mutation has mimicked such brain pathology. Here, we established a mutant mouse model carrying a K948N point mutation, corresponding to an AGS-causative K999N mutation, located in a deaminase domain of the Adar1 gene that encodes an RNA editing enzyme. Adar1K948N/K948N mice displayed postnatal growth retardation. Hyperplasia of splenic white pulps with germinal centers and hepatic focal inflammation were observed from 2 mo of age. Inflammation developed in the lungs and heart with lymphocyte infiltration in an age-dependent manner. Furthermore, white matter abnormalities with astrocytosis and microgliosis were detected at 1 y of age. The increased expression of IFN-stimulated genes was detected in multiple organs, including the brain, from birth. In addition, single-nucleus RNA sequencing revealed that this elevated expression of IFN-stimulated genes was commonly observed in all neuronal subtypes, including neurons, oligodendrocytes, and astrocytes. We further showed that a K948N point mutation reduced the RNA editing activity of ADAR1 in vivo. The pathological abnormalities found in Adar1K948N/K948N mice were ameliorated by either the concurrent deletion of MDA5, a cytosolic sensor of unedited transcripts, or the sole expression of active ADAR1 p150, an isoform of ADAR1. Collectively, such data suggest that although the degree is mild, Adar1K948N/K948N mice mimic multiple AGS phenotypes, including encephalopathy, which is caused by reduced RNA editing activity of the ADAR1 p150 isoform.
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Affiliation(s)
- Maal Inoue
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Ryuichiro Yamasaki
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Toshiharu Shibuya
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Jung In Kim
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hiroyuki Todo
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yanfang Xing
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuki Kato
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan
| | - Eiichi Morii
- Department of Pathology, Graduate School of Medicine, Osaka University, Osaka, Japan; and
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan; .,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan.,Genome Editing Research and Development Center, Graduate School of Medicine, Osaka University, Osaka, Japan
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19
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Mutations in the adenosine deaminase ADAR1 that prevent endogenous Z-RNA binding induce Aicardi-Goutières-syndrome-like encephalopathy. Immunity 2021; 54:1976-1988.e7. [PMID: 34525338 DOI: 10.1016/j.immuni.2021.08.022] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 11/22/2022]
Abstract
Mutations in the adenosine-to-inosine RNA-editing enzyme ADAR1 p150, including point mutations in the Z-RNA recognition domain Zα, are associated with Aicardi-Goutières syndrome (AGS). Here, we examined the in vivo relevance of ADAR1 binding of Z-RNA. Mutation of W197 in Zα, which abolished Z-RNA binding, reduced RNA editing. Adar1W197A/W197A mice displayed severe growth retardation after birth, broad expression of interferon-stimulated genes (ISGs), and abnormal development of multiple organs. Notably, malformation of the brain was accompanied by white matter vacuolation and gliosis, reminiscent of AGS-associated encephalopathy. Concurrent deletion of the double-stranded RNA sensor MDA5 ameliorated these abnormalities. ADAR1 (W197A) expression increased in a feedback manner downstream of type I interferons, resulting in increased RNA editing at a subset of, but not all, ADAR1 target sites. This increased expression did not ameliorate inflammation in Adar1W197A/W197A mice. Thus, editing of select endogenous RNAs by ADAR1 is essential for preventing inappropriate MDA5-mediated inflammation, with relevance to the pathogenesis of AGS.
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20
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Valori CF, Possenti A, Brambilla L, Rossi D. Challenges and Opportunities of Targeting Astrocytes to Halt Neurodegenerative Disorders. Cells 2021; 10:cells10082019. [PMID: 34440788 PMCID: PMC8395029 DOI: 10.3390/cells10082019] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases are a heterogeneous group of disorders whose incidence is likely to duplicate in the next 30 years along with the progressive aging of the western population. Non-cell-specific therapeutics or therapeutics designed to tackle aberrant pathways within neurons failed to slow down or halt neurodegeneration. Yet, in the last few years, our knowledge of the importance of glial cells to maintain the central nervous system homeostasis in health conditions has increased exponentially, along with our awareness of their fundamental and multifaced role in pathological conditions. Among glial cells, astrocytes emerge as promising therapeutic targets in various neurodegenerative disorders. In this review, we present the latest evidence showing the astonishing level of specialization that astrocytes display to fulfill the demands of their neuronal partners as well as their plasticity upon injury. Then, we discuss the controversies that fuel the current debate on these cells. We tackle evidence of a potential beneficial effect of cell therapy, achieved by transplanting astrocytes or their precursors. Afterwards, we introduce the different strategies proposed to modulate astrocyte functions in neurodegeneration, ranging from lifestyle changes to environmental cues. Finally, we discuss the challenges and the recent advancements to develop astrocyte-specific delivery systems.
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Affiliation(s)
- Chiara F. Valori
- Molecular Neuropathology of Neurodegenerative Diseases, German Centre for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Correspondence: (C.F.V.); (D.R.); Tel.: +49-7071-9254-122 (C.F.V.); +39-0382-592064 (D.R.)
| | - Agostino Possenti
- Laboratory for Research on Neurodegenerative Disorders, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy; (A.P.); (L.B.)
| | - Liliana Brambilla
- Laboratory for Research on Neurodegenerative Disorders, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy; (A.P.); (L.B.)
| | - Daniela Rossi
- Laboratory for Research on Neurodegenerative Disorders, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy; (A.P.); (L.B.)
- Correspondence: (C.F.V.); (D.R.); Tel.: +49-7071-9254-122 (C.F.V.); +39-0382-592064 (D.R.)
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21
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Zarekiani P, Breur M, Wolf NI, de Vries HE, van der Knaap MS, Bugiani M. Pathology of the neurovascular unit in leukodystrophies. Acta Neuropathol Commun 2021; 9:103. [PMID: 34082828 PMCID: PMC8173888 DOI: 10.1186/s40478-021-01206-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/24/2021] [Indexed: 01/20/2023] Open
Abstract
The blood-brain barrier is a dynamic endothelial cell barrier in the brain microvasculature that separates the blood from the brain parenchyma. Specialized brain endothelial cells, astrocytes, neurons, microglia and pericytes together compose the neurovascular unit and interact to maintain blood-brain barrier function. A disturbed brain barrier function is reported in most common neurological disorders and may play a role in disease pathogenesis. However, a comprehensive overview of how the neurovascular unit is affected in a wide range of rare disorders is lacking. Our aim was to provide further insights into the neuropathology of the neurovascular unit in leukodystrophies to unravel its potential pathogenic role in these diseases. Leukodystrophies are monogenic disorders of the white matter due to defects in any of its structural components. Single leukodystrophies are exceedingly rare, and availability of human tissue is unique. Expression of selective neurovascular unit markers such as claudin-5, zona occludens 1, laminin, PDGFRβ, aquaporin-4 and α-dystroglycan was investigated in eight different leukodystrophies using immunohistochemistry. We observed tight junction rearrangements, indicative of endothelial dysfunction, in five out of eight assessed leukodystrophies of different origin and an altered aquaporin-4 distribution in all. Aquaporin-4 redistribution indicates a general astrocytic dysfunction in leukodystrophies, even in those not directly related to astrocytic pathology or without prominent reactive astrogliosis. These findings provide further evidence for dysfunction in the orchestration of the neurovascular unit in leukodystrophies and contribute to a better understanding of the underlying disease mechanism.
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Affiliation(s)
- Parand Zarekiani
- Department of Pathology, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, de Boelelaan 1117, 1081HV Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marjolein Breur
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Child Neurology, Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Nicole I. Wolf
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Child Neurology, Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Helga E. de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marjo S. van der Knaap
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
- Department of Child Neurology, Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, Amsterdam UMC, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, de Boelelaan 1117, 1081HV Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam UMC, Amsterdam, The Netherlands
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22
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Garau J, Masnada S, Dragoni F, Sproviero D, Fogolari F, Gagliardi S, Izzo G, Varesio C, Orcesi S, Veggiotti P, Zuccotti GV, Pansarasa O, Tonduti D, Cereda C. Case Report: Novel Compound Heterozygous RNASEH2B Mutations Cause Aicardi-Goutières Syndrome. Front Immunol 2021; 12:672952. [PMID: 33981319 PMCID: PMC8107470 DOI: 10.3389/fimmu.2021.672952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/06/2021] [Indexed: 11/21/2022] Open
Abstract
Aicardi–Goutières Syndrome (AGS) is a rare disorder characterized by neurological and immunological signs. In this study we have described a child with a phenotype consistent with AGS carrying a novel compound heterozygous mutation in RNASEH2B gene. Next Generation Sequencing revealed two heterozygous variants in RNASEH2B gene. We also highlighted a reduction of RNase H2B transcript and protein levels in all the family members. Lower protein levels of RNase H2A have been observed in all the members of the family as well, whereas a deep depletion of RNase H2C has only been identified in the affected child. The structural analysis showed that both mutations remove many intramolecular contacts, possibly introducing conformational rearrangements with a decrease of the stability of RNase H2B and strongly destabilizing the RNase H2 complex. Taken together, these results highlight the importance of an integrated diagnostic approach which takes into consideration clinical, genetic, and molecular analyses.
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Affiliation(s)
- Jessica Garau
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Silvia Masnada
- Unit of Pediatric Neurology, V. Buzzi Children's Hospital, Milan, Italy.,C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Milan, Italy
| | - Francesca Dragoni
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy.,Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Daisy Sproviero
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Federico Fogolari
- Department of Mathematics, Computer Science and Physics, University of Udine, Udine, Italy
| | - Stella Gagliardi
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Giana Izzo
- C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Milan, Italy.,Department of Pediatric Radiology and Neuroradiology, V. Buzzi Children's Hospital, Milan, Italy
| | - Costanza Varesio
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Simona Orcesi
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Pierangelo Veggiotti
- Unit of Pediatric Neurology, V. Buzzi Children's Hospital, Milan, Italy.,C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Milan, Italy.,Department of Biomedical and Clinical Science "L. Sacco, University of Milan, Milan, Italy
| | - Gian Vincenzo Zuccotti
- C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Milan, Italy.,Department of Biomedical and Clinical Science "L. Sacco, University of Milan, Milan, Italy.,Department of Pediatrics, V. Buzzi Children's Hospital, Milan, Italy
| | - Orietta Pansarasa
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Davide Tonduti
- Unit of Pediatric Neurology, V. Buzzi Children's Hospital, Milan, Italy.,C.O.A.L.A (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children's Hospital, Milan, Italy
| | - Cristina Cereda
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, Pavia, Italy
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23
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De Giorgis V, Varesio C, Viri M, Giordano L, La Piana R, Tonduti D, Roncarolo F, Masnada S, Pichiecchio A, Veggiotti P, Fazzi E, Orcesi S. The epileptology of Aicardi-Goutières syndrome: electro-clinical-radiological findings. Seizure 2021; 86:197-209. [PMID: 33589296 DOI: 10.1016/j.seizure.2020.11.019] [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: 08/04/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE Although epileptic seizures occur in approximately a quarter of patients with Aicardi-Goutières syndrome (AGS), their phenotypic and electrophysiological characterization remains elusive. The aim of our study was to characterize epilepsy phenotypes and electroencephalographic (EEG) patterns in AGS and look for possible correlations with clinical, genetic and neuroradiological features. METHODS We selected patients with an established AGS diagnosis followed at three Italian reference centers. Medical records, EEGs and MRI/CT findings were reviewed. EEGs were independently and blindly reviewed by three board-certified pediatric epileptologists. Chi square and Fisher's exact tests were used to test associations between epilepsy and EEG feature categories and clinical, radiological and genetic variables. RESULTS Twenty-seven patients were enrolled. We reviewed 63 EEGs and at least one brain MRI scan per patient. Epilepsy, mainly in the form of epileptic spasms and focal seizures, was present in 37 % of the cohort; mean age at epilepsy onset was 9.5 months (range 1-36). The presence of epilepsy was associated with calcification severity (p = 0.016) and startle reactions (p = 0.05). Organization of EEG electrical activity appeared to be disrupted or markedly disrupted in 73 % of cases. Severe EEG disorganization correlated with microcephaly (p < 0.001) and highly abnormal MRI T2-weighted signal intensity in white matter (p = 0.022). Physiological organization of the EEG was found to be better preserved during sleep (87 %) than wakefulness (38 %). Focal slow activity was recorded in more than one third of cases. Fast activity, either diffuse or with frontal location, was more frequent in the awake state (78 %) than in sleep (50 %). Interictal epileptiform discharges (IEDs) were present in 33 % of awake and 45 % of sleep recordings. IEDs during sleep were associated with a higher risk of a epileptic seizures (p = 0.008). SIGNIFICANCE The hallmarks of EEG recordings in AGS were found to be: disruption of electrical organization, the presence of focal slow and fast activity, and the presence of IEDs, both in patients with and in those without epilepsy. The associations between epilepsy and calcification and between EEG pattern and the finding of a highly abnormal white matter T2 signal intensity suggest a common anatomical correlate. However, the complex anatomical-electroclinical basis of AGS-related epilepsy still requires further elucidation.
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Affiliation(s)
- Valentina De Giorgis
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy
| | - Costanza Varesio
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy.
| | - Maurizio Viri
- Department of Child Neurology and Psychiatry, AOU Maggiore della Carità Novara, Novara, Italy
| | - Lucio Giordano
- Child Neurology and Psychiatry Unit, ASST Spedali Civili di Brescia, Brescia, Italy
| | - Roberta La Piana
- Department of Neuroradiology and Laboratory of Neurogenetics of Motion, Neurological Institute and Hospital, McGill University, Montreal, QC H3A2B4, Canada
| | - Davide Tonduti
- Pediatric Neurology Unit - COALA (Center for Diagnosis and Treatment of Leukodystrophies) -V. Buzzi Children's Hospital, Milan, Italy
| | - Federico Roncarolo
- Institute of Public Health Research of University of Montreal (IRSPUM), University of Montreal, Montreal, QC, Canada
| | - Silvia Masnada
- Pediatric Neurology Unit - COALA (Center for Diagnosis and Treatment of Leukodystrophies) -V. Buzzi Children's Hospital, Milan, Italy
| | - Anna Pichiecchio
- Neuroradiology Unit, IRCCS Mondino Foundation, Pavia, Italy; Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Pierangelo Veggiotti
- Pediatric Neurology Unit - COALA (Center for Diagnosis and Treatment of Leukodystrophies) -V. Buzzi Children's Hospital, Milan, Italy; Biomedical and Clinical Sciences Department, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Elisa Fazzi
- Child Neurology and Psychiatry Unit, ASST Spedali Civili di Brescia, Brescia, Italy; Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Simona Orcesi
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy; Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
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24
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de Waard DM, Bugiani M. Astrocyte-Oligodendrocyte-Microglia Crosstalk in Astrocytopathies. Front Cell Neurosci 2020; 14:608073. [PMID: 33328899 PMCID: PMC7710860 DOI: 10.3389/fncel.2020.608073] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022] Open
Abstract
Defective astrocyte function due to a genetic mutation can have major consequences for microglia and oligodendrocyte physiology, which in turn affects the white matter integrity of the brain. This review addresses the current knowledge on shared and unique pathophysiological mechanisms of astrocytopathies, including vanishing white matter, Alexander disease, megalencephalic leukoencephalopathy with subcortical cysts, Aicardi-Goutières syndrome, and oculodentodigital dysplasia. The mechanisms of disease include protein accumulation, unbalanced secretion of extracellular matrix proteins, pro- and anti-inflammatory molecules, cytokines and chemokines by astrocytes, as well as an altered gap junctional network and a changed ionic and nutrient homeostasis. Interestingly, the extent to which astrogliosis and microgliosis are present in these astrocytopathies is highly variable. An improved understanding of astrocyte-microglia-oligodendrocyte crosstalk might ultimately lead to the identification of druggable targets for these, currently untreatable, severe conditions.
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Affiliation(s)
| | - Marianna Bugiani
- Department of Pathology, VU Medical center, Amsterdam UMC, Amsterdam, Netherlands
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25
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Garcia LM, Hacker JL, Sase S, Adang L, Almad A. Glial cells in the driver seat of leukodystrophy pathogenesis. Neurobiol Dis 2020; 146:105087. [PMID: 32977022 DOI: 10.1016/j.nbd.2020.105087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 08/16/2020] [Accepted: 09/18/2020] [Indexed: 01/24/2023] Open
Abstract
Glia cells are often viewed as support cells in the central nervous system, but recent discoveries highlight their importance in physiological functions and in neurological diseases. Central to this are leukodystrophies, a group of progressive, neurogenetic disease affecting white matter pathology. In this review, we take a closer look at multiple leukodystrophies, classified based on the primary glial cell type that is affected. While white matter diseases involve oligodendrocyte and myelin loss, we discuss how astrocytes and microglia are affected and impinge on oligodendrocyte, myelin and axonal pathology. We provide an overview of the leukodystrophies covering their hallmark features, clinical phenotypes, diverse molecular pathways, and potential therapeutics for clinical trials. Glial cells are gaining momentum as cellular therapeutic targets for treatment of demyelinating diseases such as leukodystrophies, currently with no treatment options. Here, we bring the much needed attention to role of glia in leukodystrophies, an integral step towards furthering disease comprehension, understanding mechanisms and developing future therapeutics.
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Affiliation(s)
- Luis M Garcia
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Julia L Hacker
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Laura Adang
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Akshata Almad
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA.
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26
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A phenolic small molecule inhibitor of RNase L prevents cell death from ADAR1 deficiency. Proc Natl Acad Sci U S A 2020; 117:24802-24812. [PMID: 32958664 PMCID: PMC7547215 DOI: 10.1073/pnas.2006883117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The OAS–RNase L system is an innate immunity pathway activated by viral infection. Viral dsRNA stimulates OAS enzymes to produce short 2′,5′-oligoadenylates (2-5A) that activate RNase L, resulting in cleavage of single-stranded (ss) RNA. We discovered a small-molecule inhibitor of RNase L that rescues the toxic phenotype of cells deficient in the dsRNA-editing enzyme ADAR1. ADAR1 destabilizes dsRNA to prevent OAS activity. ADAR1 mutations are responsible for a subset of cases of Aicardi-Goutières syndrome (AGS), a severe neurodevelopmental and inflammatory genetic disease of children with no effective medical therapy. We posit that an RNase L inhibitor may have utility against cases of AGS in which RNase L is activated and other indications where overactivation of RNase L is harmful. The oligoadenylate synthetase (OAS)–RNase L system is an IFN-inducible antiviral pathway activated by viral infection. Viral double-stranded (ds) RNA activates OAS isoforms that synthesize the second messenger 2-5A, which binds and activates the pseudokinase-endoribonuclease RNase L. In cells, OAS activation is tamped down by ADAR1, an adenosine deaminase that destabilizes dsRNA. Mutation of ADAR1 is one cause of Aicardi-Goutières syndrome (AGS), an interferonopathy in children. ADAR1 deficiency in human cells can lead to RNase L activation and subsequent cell death. To evaluate RNase L as a possible therapeutic target for AGS, we sought to identify small-molecule inhibitors of RNase L. A 500-compound library of protein kinase inhibitors was screened for modulators of RNase L activity in vitro. We identified ellagic acid (EA) as a hit with 10-fold higher selectivity against RNase L compared with its nearest paralog, IRE1. SAR analysis identified valoneic acid dilactone (VAL) as a superior inhibitor of RNase L, with 100-fold selectivity over IRE1. Mechanism-of-action analysis indicated that EA and VAL do not bind to the pseudokinase domain of RNase L despite acting as ATP competitive inhibitors of the protein kinase CK2. VAL is nontoxic and functional in cells, although with a 1,000-fold decrease in potency, as measured by RNA cleavage activity in response to treatment with dsRNA activator or by rescue of cell lethality resulting from self dsRNA induced by ADAR1 deficiency. These studies lay the foundation for understanding novel modes of regulating RNase L function using small-molecule inhibitors and avenues of therapeutic potential.
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27
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Ma X, Yang F, Hua Z. Genetic diagnosis of neonatal-onset seizures. Genes Dis 2019; 6:441-447. [PMID: 31832524 PMCID: PMC6888710 DOI: 10.1016/j.gendis.2019.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/02/2019] [Indexed: 12/28/2022] Open
Abstract
Many seizures in neonates are due to early-onset epilepsy, which is often difficult to diagnose, especially to explore the causes. Recently, the development of next-generation sequencing (NGS) has led to the discovery of a large number of genes involved in epilepsy. This may improve prompt detection of early-onset epilepsy in neonates. This study aimed at analyzing the genotype-phenotype correlations in neonates with seizures in a bid to improve the understanding of genetic diagnosis of early-onset epilepsy. Clinical features and prognosis of 15 children who underwent genetic testing having had unexplained seizures from February 2016 to May 2018 in Children's Hospital of Chongqing Medical University were analyzed retrospectively. The salient findings were: poor response to stimulus and abnormal electroencephalogram (EEG) in the initial period were observed in the group with concomitant genetic abnormalities. Despite the recent progress in genetic technology, molecular diagnosis for neonatal-onset epilepsy can be challenging due to genetic and phenotypic heterogeneities. However, some genotypes are associated with specific clinical manifestations and EEG patterns. Therefore, in-depth understanding of genotype-phenotype correlations would be useful to clinicians managing neonates with early-onset seizures.
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Affiliation(s)
- Xueling Ma
- The Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China
- National Demonstration Base of Standardized Training Base for Resident Physicians, Chongqing, 400014, China
| | - Fengzhu Yang
- The Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China
- National Demonstration Base of Standardized Training Base for Resident Physicians, Chongqing, 400014, China
| | - Ziyu Hua
- The Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, 400014, China
- Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, 400014, China
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28
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Choubey D. Type I interferon (IFN)-inducible Absent in Melanoma 2 proteins in neuroinflammation: implications for Alzheimer's disease. J Neuroinflammation 2019; 16:236. [PMID: 31771614 PMCID: PMC6880379 DOI: 10.1186/s12974-019-1639-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/11/2019] [Indexed: 01/09/2023] Open
Abstract
Cumulative evidence indicates that activation of innate immune responses in the central nervous system (CNS) induces the expression of type 1 interferons (T1 IFNs), a family of cytokines. The T1 IFNs (IFN-α/β), through activation of the JAK/STAT-signaling in microglia, astrocytes, and neurons, induce the expression of IFN-inducible proteins, which mediate the pro- and anti-inflammatory functions of IFNs. Accordingly, T1 IFN-inducible Absent in Melanoma 2 proteins (murine Aim2 and human AIM2) negatively regulate the expression of TI IFNs and, upon sensing higher levels of cytosolic DNA, assemble the Aim2/AIM2 inflammasome, resulting in activation of caspase-1, pyroptosis, and the secretion of pro-inflammatory cytokines (e.g., IL-1β and IL-18). Of interest, studies have indicated a role for the Aim2/AIM2 proteins in neuroinflammation and neurodegenerative diseases, including Alzheimer's disease (AD). The ability of Aim2/AIM2 proteins to exert pro- and anti-inflammatory effects in CNS may depend upon age, sex hormones, cell-types, and the expression of species-specific negative regulators of the Aim2/AIM2 inflammasome. Therefore, we discuss the role of Aim2/AIM2 proteins in the development of AD. An improved understanding of the role of Absent in Melanoma 2 proteins in AD could identify new approaches to treat patients.
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Affiliation(s)
- Divaker Choubey
- Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, P. O. Box 670056, Cincinnati, OH, 45267, USA.
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29
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Abstract
Leukodystrophies are genetically determined disorders affecting the white matter of the central nervous system. The combination of MRI pattern recognition and next-generation sequencing for the definition of novel disease entities has recently demonstrated that many leukodystrophies are due to the primary involvement and/or mutations in genes selectively expressed by cell types other than the oligodendrocytes, the myelin-forming cells in the brain. This has led to a new definition of leukodystrophies as genetic white matter disorders resulting from the involvement of any white matter structural component. As a result, the research has shifted its main focus from oligodendrocytes to other types of neuroglia. Astrocytes are the housekeeping cells of the nervous system, responsible for maintaining homeostasis and normal brain physiology and to orchestrate repair upon injury. Several lines of evidence show that astrocytic interactions with the other white matter cellular constituents play a primary pathophysiologic role in many leukodystrophies. These are thus now classified as astrocytopathies. This chapter addresses how the crosstalk between astrocytes, other glial cells, axons and non-neural cells are essential for the integrity and maintenance of the white matter in health. It also addresses the current knowledge of the cellular pathomechanisms of astrocytic leukodystrophies, and specifically Alexander disease, vanishing white matter, megalencephalic leukoencephalopathy with subcortical cysts and Aicardi-Goutière Syndrome.
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Affiliation(s)
- M S Jorge
- Department of Pathology, Free University Medical Centre, Amsterdam, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, Free University Medical Centre, Amsterdam, The Netherlands.
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30
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Bugiani M, Breur M. Leukodystrophies due to astroyctic dysfunction. Brain Pathol 2019; 28:369-371. [PMID: 29740940 DOI: 10.1111/bpa.12607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/08/2018] [Indexed: 01/24/2023] Open
Abstract
Leukodystrophies are genetically determined disorders due to defects in any structural components of the brain white matter. This mini-symposium presents a selection of leukodystrophies due to astrocytic dysfunction, the astrocytopathies. Examples are provided of astrocytopathies due to defects in astrocyte-specific proteins and in which astrocytes play a major role in the pathophysiology. Knowledge on the disease mechanisms underlying these leukodystrophies also provides information how loss of physiologic functions and gain of detrimental functions in astrocytes leads to degeneration of the white matter.
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Affiliation(s)
- Marianna Bugiani
- Department of Pathology, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marjolein Breur
- Department of Child Neurology, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands
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