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Saad H, El Baba B, Tfaily A, Kobeissy F, Gonzalez JG, Refai D, Rodts GR, Mustroph C, Gimbel D, Grossberg J, Barrow DL, Gary MF, Alawieh AM. Complement-dependent neuroinflammation in spinal cord injury: from pathology to therapeutic implications. Neural Regen Res 2025; 20:1324-1335. [PMID: 38845224 DOI: 10.4103/nrr.nrr-d-24-00116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 04/29/2024] [Indexed: 07/31/2024] Open
Abstract
Spinal cord injury remains a major cause of disability in young adults, and beyond acute decompression and rehabilitation, there are no pharmacological treatments to limit the progression of injury and optimize recovery in this population. Following the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation, a similar role for complement in spinal neuroinflammation is a focus of ongoing research. In this work, we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins, triggers of complement activation, and role of effector functions in the pathology. We study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris, and or activation via antibody binding to damage-associated molecular patterns. Several effector functions of complement have been implicated in spinal cord injury, and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord injury. Following this pathophysiological review, we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human subjects. This review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury, to evaluate the phases of involvement of opsonins and anaphylatoxins, and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.
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Affiliation(s)
- Hassan Saad
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Bachar El Baba
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Ali Tfaily
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Firas Kobeissy
- Center for Neurotrauma, Multiomics & Biomarkers (CNMB), Morehouse School of Medicine, Atlanta, GA, USA
| | | | - Daniel Refai
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Gerald R Rodts
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Christian Mustroph
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - David Gimbel
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Jonathan Grossberg
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniel L Barrow
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Matthew F Gary
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Ali M Alawieh
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
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Kennedy PGE, Fultz M, Phares J, Yu X. Immunoglobulin G and Complement as Major Players in the Neurodegeneration of Multiple Sclerosis. Biomolecules 2024; 14:1210. [PMID: 39456143 PMCID: PMC11506455 DOI: 10.3390/biom14101210] [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: 08/13/2024] [Revised: 09/22/2024] [Accepted: 09/24/2024] [Indexed: 10/28/2024] Open
Abstract
Multiple Sclerosis (MS) is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS) and is termed as one of the most common causes of neurological disability in young adults. Axonal loss and neuronal cell damage are the primary causes of disease progression and disability. Yet, little is known about the mechanism of neurodegeneration in the disease, a limitation that impairs the development of more effective treatments for progressive MS. MS is characterized by the presence of oligoclonal bands and raised levels of immunoglobulins in the CNS. The role of complement in the demyelinating process has been detected in both experimental animal models of MS and within the CNS of affected MS patients. Furthermore, both IgG antibodies and complement activation can be detected in the demyelinating plaques and cortical gray matter lesions. We propose here that both immunoglobulins and complement play an active role in the neurodegenerative process of MS. We hypothesize that the increased CNS IgG antibodies form IgG aggregates and bind complement C1q with high affinity, activating the classical complement pathway. This results in neuronal cell damage, which leads to neurodegeneration and demyelination in MS.
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Affiliation(s)
- Peter G. E. Kennedy
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G61 1QH, UK;
| | - Matthew Fultz
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (M.F.); (J.P.)
| | - Jeremiah Phares
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (M.F.); (J.P.)
| | - Xiaoli Yu
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (M.F.); (J.P.)
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Salas-Lucia F, Escamilla S, Bianco AC, Dumitrescu A, Refetoff S. Impaired T3 uptake and action in MCT8-deficient cerebral organoids underlie Allan-Herndon-Dudley syndrome. JCI Insight 2024; 9:e174645. [PMID: 38376950 PMCID: PMC11128209 DOI: 10.1172/jci.insight.174645] [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: 08/09/2023] [Accepted: 02/15/2024] [Indexed: 02/22/2024] Open
Abstract
Patients with mutations in the thyroid hormone (TH) cell transporter monocarboxylate transporter 8 (MCT8) gene develop severe neuropsychomotor retardation known as Allan-Herndon-Dudley syndrome (AHDS). It is assumed that this is caused by a reduction in TH signaling in the developing brain during both intrauterine and postnatal developmental stages, and treatment remains understandably challenging. Given species differences in brain TH transporters and the limitations of studies in mice, we generated cerebral organoids (COs) using human induced pluripotent stem cells (iPSCs) from MCT8-deficient patients. MCT8-deficient COs exhibited (i) altered early neurodevelopment, resulting in smaller neural rosettes with thinner cortical units, (ii) impaired triiodothyronine (T3) transport in developing neural cells, as assessed through deiodinase-3-mediated T3 catabolism, (iii) reduced expression of genes involved in cerebral cortex development, and (iv) reduced T3 inducibility of TH-regulated genes. In contrast, the TH analogs 3,5-diiodothyropropionic acid and 3,3',5-triiodothyroacetic acid triggered normal responses (induction/repression of T3-responsive genes) in MCT8-deficient COs, constituting proof of concept that lack of T3 transport underlies the pathophysiology of AHDS and demonstrating the clinical potential for TH analogs to be used in treating patients with AHDS. MCT8-deficient COs represent a species-specific relevant preclinical model that can be utilized to screen drugs with potential benefits as personalized therapeutics for patients with AHDS.
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Affiliation(s)
- Federico Salas-Lucia
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Department of Medicine, The University of Chicago, Chicago, Illinois, USA
| | - Sergio Escamilla
- Instituto de Neurociencias de Alicante, Miguel Hernández-CSIC University, Sant Joan d’Alacant, Alicante, Spain
| | - Antonio C. Bianco
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Department of Medicine, The University of Chicago, Chicago, Illinois, USA
| | - Alexandra Dumitrescu
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Department of Medicine, The University of Chicago, Chicago, Illinois, USA
- Committee on Molecular Metabolism and Nutrition
| | - Samuel Refetoff
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Department of Medicine, The University of Chicago, Chicago, Illinois, USA
- Department of Pediatrics, and Committee on Genetics, The University of Chicago, Chicago, Illinois, USA
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Zhou W, Graner M, Paucek P, Beseler C, Boisen M, Bubak A, Asturias F, George W, Graner A, Ormond D, Vollmer T, Alvarez E, Yu X. Multiple sclerosis plasma IgG aggregates induce complement-dependent neuronal apoptosis. Cell Death Dis 2023; 14:254. [PMID: 37031195 PMCID: PMC10082781 DOI: 10.1038/s41419-023-05783-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 04/10/2023]
Abstract
Grey matter pathology is central to the progression of multiple sclerosis (MS). We discovered that MS plasma immunoglobulin G (IgG) antibodies, mainly IgG1, form large aggregates (>100 nm) which are retained in the flow-through after binding to Protein A. Utilizing an annexin V live-cell apoptosis detection assay, we demonstrated six times higher levels of neuronal apoptosis induced by MS plasma IgG aggregates (n = 190, from two cohorts) compared to other neurological disorders (n = 116) and healthy donors (n = 44). MS IgG aggregate-mediated, complement-dependent neuronal apoptosis was evaluated in multiple model systems including primary human neurons, primary human astrocytes, neuroblastoma SH-SY5Y cells, and newborn mouse brain slices. Immunocytochemistry revealed the co-deposition of IgG, early and late complement activation products (C1q, C3b, and membrane attack complex C5b9), as well as active caspase 3 in treated neuronal cells. Furthermore, we found that MS plasma cytotoxic antibodies are not present in Protein G flow-through, nor in the paired plasma. The neuronal apoptosis can be inhibited by IgG depletion, disruption of IgG aggregates, pan-caspase inhibitor, and is completely abolished by digestion with IgG-cleaving enzyme IdeS. Transmission electron microscopy and nanoparticle tracking analysis revealed the sizes of MS IgG aggregates are greater than 100 nm. Our data support the pathological role of MS IgG antibodies and corroborate their connection to complement activation and axonal damage, suggesting that apoptosis may be a mechanism of neurodegeneration in MS.
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Affiliation(s)
- Wenbo Zhou
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Michael Graner
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Petr Paucek
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Cheryl Beseler
- Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Matthew Boisen
- Zalgen Labs, LLC, 12635 E. Montview Blvd., Suite 131, Aurora, Colorado, 80045, USA
| | - Andrew Bubak
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Francisco Asturias
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Woro George
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Arin Graner
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - David Ormond
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Timothy Vollmer
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Enrique Alvarez
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Xiaoli Yu
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA.
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Saez-Calveras N, Brewster AL, Stuve O. The validity of animal models to explore the pathogenic role of the complement system in multiple sclerosis: A review. Front Mol Neurosci 2022; 15:1017484. [PMID: 36311030 PMCID: PMC9606595 DOI: 10.3389/fnmol.2022.1017484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/26/2022] [Indexed: 11/26/2022] Open
Abstract
Animal models of multiple sclerosis (MS) have been extensively used to characterize the disease mechanisms in MS, as well as to identify potential pharmacologic targets for this condition. In recent years, the immune complement system has gained increased attention as an important effector in the pathogenesis of MS. Evidence from histological, serum, and CSF studies of patients supports an involvement of complement in both relapsing-remitting and progressive MS. In this review, we discuss the history and advances made on the use of MS animal models to profile the effects of the complement system in this condition. The first studies that explored the complement system in the context of MS used cobra venom factor (CVF) as a complement depleting agent in experimental autoimmune encephalomyelitis (EAE) Lewis rats. Since then, multiple mice and rat models of MS have revealed a role of C3 and the alternative complement cascade in the opsonization and phagocytosis of myelin by microglia and myeloid cells. Studies using viral vectors, genetic knockouts and pharmacologic complement inhibitors have also shown an effect of complement in synaptic loss. Antibody-mediated EAE models have revealed an involvement of the C1 complex and the classical complement as an effector of the humoral response in this disease. C1q itself may also be involved in modulating microglia activation and oligodendrocyte differentiation in these animals. In addition, animal and in vitro models have revealed that multiple complement factors may act as modulators of both the innate and adaptive immune responses. Finally, evidence gathered from mice models suggests that the membrane attack complex (MAC) may even exert protective roles in the chronic stages of EAE. Overall, this review summarizes the importance of MS animal models to better characterize the role of the complement system and guide future therapeutic approaches in this condition.
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Affiliation(s)
- Nil Saez-Calveras
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Neurology Section, Parkland Hospital, Dallas, TX, United States
| | - Amy L. Brewster
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, United States
| | - Olaf Stuve
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Neurology Section, VA North Texas Health Care System, Dallas, TX, United States
- Peter O’Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States
- *Correspondence: Olaf Stuve,
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Pike SC, Welsh N, Linzey M, Gilli F. Theiler’s virus-induced demyelinating disease as an infectious model of progressive multiple sclerosis. Front Mol Neurosci 2022; 15:1019799. [PMID: 36311024 PMCID: PMC9606571 DOI: 10.3389/fnmol.2022.1019799] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/27/2022] [Indexed: 11/13/2022] Open
Abstract
Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease of unknown etiology. However, several studies suggest that infectious agents, e.g., Human Herpes Viruses (HHV), may be involved in triggering the disease. Molecular mimicry, bystander effect, and epitope spreading are three mechanisms that can initiate immunoreactivity leading to CNS autoimmunity in MS. Theiler’s murine encephalomyelitis virus (TMEV)-induced demyelinating disease (TMEV-IDD) is a pre-clinical model of MS in which intracerebral inoculation of TMEV results in a CNS autoimmune disease that causes demyelination, neuroaxonal damage, and progressive clinical disability. Given the spectra of different murine models used to study MS, this review highlights why TMEV-IDD represents a valuable tool for testing the viral hypotheses of MS. We initially describe how the main mechanisms of CNS autoimmunity have been identified across both MS and TMEV-IDD etiology. Next, we discuss how adaptive, innate, and CNS resident immune cells contribute to TMEV-IDD immunopathology and how this relates to MS. Lastly, we highlight the sexual dimorphism observed in TMEV-IDD and MS and how this may be tied to sexually dimorphic responses to viral infections. In summary, TMEV-IDD is an underutilized murine model that recapitulates many unique aspects of MS; as we learn more about the nature of viral infections in MS, TMEV-IDD will be critical in testing the future therapeutics that aim to intervene with disease onset and progression.
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Affiliation(s)
- Steven C. Pike
- Department of Neurology, Dartmouth Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, United States
- Integrative Neuroscience at Dartmouth, Dartmouth College, Hanover, NH, United States
| | - Nora Welsh
- Department of Neurology, Dartmouth Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, United States
- Integrative Neuroscience at Dartmouth, Dartmouth College, Hanover, NH, United States
| | - Michael Linzey
- Department of Neurology, Dartmouth Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, United States
- Integrative Neuroscience at Dartmouth, Dartmouth College, Hanover, NH, United States
| | - Francesca Gilli
- Department of Neurology, Dartmouth Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, United States
- Integrative Neuroscience at Dartmouth, Dartmouth College, Hanover, NH, United States
- *Correspondence: Francesca Gilli,
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