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Abarca-Merlin DM, Martínez-Durán JA, Medina-Pérez JD, Rodríguez-Santos G, Alvarez-Arellano L. From Immunity to Neurogenesis: Toll-like Receptors as Versatile Regulators in the Nervous System. Int J Mol Sci 2024; 25:5711. [PMID: 38891900 PMCID: PMC11171594 DOI: 10.3390/ijms25115711] [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: 03/26/2024] [Revised: 05/10/2024] [Accepted: 05/11/2024] [Indexed: 06/21/2024] Open
Abstract
Toll-like receptors (TLRs) are among the main components of the innate immune system. They can detect conserved structures in microorganisms and molecules associated with stress and cellular damage. TLRs are expressed in resident immune cells and both neurons and glial cells of the nervous system. Increasing evidence is emerging on the participation of TLRs not only in the immune response but also in processes of the nervous system, such as neurogenesis and cognition. Below, we present a review of the literature that evaluates the expression and role of TLRs in processes such as neurodevelopment, behavior, cognition, infection, neuroinflammation, and neurodegeneration.
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Affiliation(s)
- Daniela Melissa Abarca-Merlin
- Laboratorio de Investigación en Neurociencias, Hospital Infantil de México Federico Gómez, Av. Dr. Márquez 162. Colonia Doctores, Mexico City 06720, Mexico; (D.M.A.-M.)
| | - J. Abigail Martínez-Durán
- Laboratorio de Investigación en Neurociencias, Hospital Infantil de México Federico Gómez, Av. Dr. Márquez 162. Colonia Doctores, Mexico City 06720, Mexico; (D.M.A.-M.)
| | - J. David Medina-Pérez
- Laboratorio de Investigación en Neurociencias, Hospital Infantil de México Federico Gómez, Av. Dr. Márquez 162. Colonia Doctores, Mexico City 06720, Mexico; (D.M.A.-M.)
| | - Guadalupe Rodríguez-Santos
- Laboratorio de Investigación en Neurociencias, Hospital Infantil de México Federico Gómez, Av. Dr. Márquez 162. Colonia Doctores, Mexico City 06720, Mexico; (D.M.A.-M.)
| | - Lourdes Alvarez-Arellano
- Laboratorio de Investigación en Neurociencias, Hospital Infantil de México Federico Gómez, Av. Dr. Márquez 162. Colonia Doctores, Mexico City 06720, Mexico; (D.M.A.-M.)
- CONAHCYT-Hospital Infantil de México Federico Gómez, Mexico City 06720, Mexico
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Morrow AL, Boero G, Balan I. Emerging evidence for endogenous neurosteroid modulation of pro-inflammatory and anti-inflammatory pathways that impact neuropsychiatric disease. Neurosci Biobehav Rev 2024; 158:105558. [PMID: 38244954 DOI: 10.1016/j.neubiorev.2024.105558] [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: 08/01/2023] [Revised: 12/01/2023] [Accepted: 01/16/2024] [Indexed: 01/22/2024]
Abstract
This mini-review presents emerging evidence that endogenous neurosteroids modulate both pro- and anti-inflammatory signaling by immune cells and brain cells that contribute to depression, alcohol use disorders, and other inflammatory conditions. We first review the literature on pregnenolone and allopregnanolone inhibition of proinflammatory neuroimmune pathways in the periphery and the brain - effects that are independent of GABAergic mechanisms. We follow with evidence for neurosteroid enhancement of anti-inflammatory and protective pathways in brain and immune cells. These studies draw clinical relevance from a large body of evidence that pro-inflammatory immune signaling is dysregulated in many brain disorders and the fact that neurosteroids inhibit the same inflammatory pathways that are activated in depression, alcohol use disorders and other inflammatory conditions. Thus, we describe evidence that neurosteroid levels are decreased and neurosteroid supplementation has therapeutic efficacy in these neuropsychiatric conditions. We conclude with a perspective that endogenous regulation of immune balance between pro- and anti-inflammatory pathways by neurosteroid signaling is essential to prevent the onset of disease. Deficits in neurosteroids may unleash excessive pro-inflammatory activation which progresses in a feed-forward manner to disrupt brain networks that regulate stress, emotion and motivation. Neurosteroids can block various inflammatory pathways in mouse and human macrophages, rat brain and human blood and therefore provide new hope for treatment of intractable conditions that involve excessive inflammatory signaling.
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Affiliation(s)
- A Leslie Morrow
- Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Giorgia Boero
- Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Irina Balan
- Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Wei H, Wu S, Mai L, Yang L, Zou W, Peng H. Cbl-b negatively regulates TLR/MyD88-mediated anti- Toxoplasma gondii immunity. Microbiol Spectr 2023; 11:e0007423. [PMID: 37909781 PMCID: PMC10714978 DOI: 10.1128/spectrum.00074-23] [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: 01/08/2023] [Accepted: 08/30/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE This is the first report that a human E3 ubiquitin ligase, Casitas B-lineage lymphoma proto-oncogene B (Cbl-b), functions as a host dependency factor for the intracellular protozoan Toxoplasma gondii and the mechanism for how T. gondii infection inhibits the TLR/MyD88 innate immunity pathway through MyD88 degradation mediated by Cbl-b. This finding is an impactful contribution for understanding the host cell immunity against T. gondii infection.
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Affiliation(s)
- Haixia Wei
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
- Department of Pathogen Biology, School of Basic Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shuizhen Wu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Liying Mai
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Lili Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Weihao Zou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
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Couch ACM, Solomon S, Duarte RRR, Marrocu A, Sun Y, Sichlinger L, Matuleviciute R, Polit LD, Hanger B, Brown A, Kordasti S, Srivastava DP, Vernon AC. Acute IL-6 exposure triggers canonical IL6Ra signaling in hiPSC microglia, but not neural progenitor cells. Brain Behav Immun 2023; 110:43-59. [PMID: 36781081 PMCID: PMC10682389 DOI: 10.1016/j.bbi.2023.02.007] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/20/2022] [Accepted: 02/10/2023] [Indexed: 02/13/2023] Open
Abstract
BACKGROUND Prenatal exposure to elevated interleukin (IL)-6 levels is associated with increased risk for psychiatric disorders with a putative neurodevelopmental origin, such as schizophrenia (SZ), autism spectrum condition (ASC) and bipolar disorder (BD). Although rodent models provide causal evidence for this association, we lack a detailed understanding of the cellular and molecular mechanisms in human model systems. To close this gap, we characterized the response of human induced pluripotent stem cell (hiPSC-)derived microglia-like cells (MGL) and neural progenitor cells (NPCs) to IL-6 in monoculture. RESULTS We observed that human forebrain NPCs did not respond to acute IL-6 exposure in monoculture at both protein and transcript levels due to the absence of IL6R expression and soluble (s)IL6Ra secretion. By contrast, acute IL-6 exposure resulted in STAT3 phosphorylation and increased IL6, JMJD3 and IL10 expression in MGL, confirming activation of canonical IL6Ra signaling. Bulk RNAseq identified 156 up-regulated genes (FDR < 0.05) in MGL following acute IL-6 exposure, including IRF8, REL, HSPA1A/B and OXTR, which significantly overlapped with an up-regulated gene set from human post-mortem brain tissue from individuals with schizophrenia. Acute IL-6 stimulation significantly increased MGL motility, consistent with gene ontology pathways highlighted from the RNAseq data and replicating rodent model indications that IRF8 regulates microglial motility. Finally, IL-6 induces MGLs to secrete CCL1, CXCL1, MIP-1α/β, IL-8, IL-13, IL-16, IL-18, MIF and Serpin-E1 after 3 h and 24 h. CONCLUSION Our data provide evidence for cell specific effects of acute IL-6 exposure in a human model system, ultimately suggesting that microglia-NPC co-culture models are required to study how IL-6 influences human cortical neural progenitor cell development in vitro.
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Affiliation(s)
- Amalie C M Couch
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Shiden Solomon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Rodrigo R R Duarte
- Department of Social, Genetic & Developmental Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK; Department of Medicine, Weill Cornell Medical College, Cornell University, NY, USA
| | - Alessia Marrocu
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Division of Immunology, Infection and Inflammatory Disease, King's College London, London, UK
| | - Yiqing Sun
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Laura Sichlinger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Rugile Matuleviciute
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Lucia Dutan Polit
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Bjørn Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Amelia Brown
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Shahram Kordasti
- Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Deepak P Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Anthony C Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK.
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Acioglu C, Heary RF, Elkabes S. Roles of neuronal toll-like receptors in neuropathic pain and central nervous system injuries and diseases. Brain Behav Immun 2022; 102:163-178. [PMID: 35176442 DOI: 10.1016/j.bbi.2022.02.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/12/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022] Open
Abstract
Toll-like receptors (TLRs) are innate immune receptors that are expressed in immune cells as well as glia and neurons of the central and peripheral nervous systems. They are best known for their role in the host defense in response to pathogens and for the induction of inflammation in infectious and non-infectious diseases. In the central nervous system (CNS), TLRs modulate glial and neuronal functions as well as innate immunity and neuroinflammation under physiological or pathophysiological conditions. The majority of the studies on TLRs in CNS pathologies investigated their overall contribution without focusing on a particular cell type, or they analyzed TLRs in glia and infiltrating immune cells in the context of neuroinflammation and cellular activation. The role of neuronal TLRs in CNS diseases and injuries has received little attention and remains underappreciated. The primary goal of this review is to summarize findings demonstrating the pivotal and unique roles of neuronal TLRs in neuropathic pain, Alzheimer's disease, Parkinson's disease and CNS injuries. We discuss how the current findings warrant future investigations to better define the specific contributions of neuronal TLRs to these pathologies. We underline the paucity of information regarding the role of neuronal TLRs in other neurodegenerative, demyelinating, and psychiatric diseases. We draw attention to the importance of broadening research on neuronal TLRs in view of emerging evidence demonstrating their distinctive functional properties.
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Affiliation(s)
- Cigdem Acioglu
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Robert F Heary
- Department of Neurological Surgery, Hackensack Meridian School of Medicine, Mountainside Medical Center, Montclair, NJ 07042, United States
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
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Goldstein RS, Kinchington PR. Varicella Zoster Virus Neuronal Latency and Reactivation Modeled in Vitro. Curr Top Microbiol Immunol 2021; 438:103-134. [PMID: 34904194 DOI: 10.1007/82_2021_244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Latency and reactivation in neurons are critical aspects of VZV pathogenesis that have historically been difficult to investigate. Viral genomes are retained in many human ganglia after the primary infection, varicella; and about one-third of the naturally infected VZV seropositive population reactivates latent virus, which most often clinically manifests as herpes zoster (HZ or Shingles). HZ is frequently complicated by acute and chronic debilitating pain for which there remains a need for more effective treatment options. Understanding of the latent state is likely to be essential in the design of strategies to reduce reactivation. Experimentally addressing VZV latency has been difficult because of the strict human species specificity of VZV and the fact that until recently, experimental reactivation had not been achieved. We do not yet know the neuron subtypes that harbor latent genomes, whether all can potentially reactivate, what the drivers of VZV reactivation are, and how immunity interplays with the latent state to control reactivation. However, recent advances have enabled a picture of VZV latency to start to emerge. The first is the ability to detect the latent viral genome and its expression in human ganglionic tissues with extraordinary sensitivity. The second, the subject of this chapter, is the development of in vitro human neuron systems permitting the modeling of latent states that can be experimentally reactivated. This review will summarize recent advances of in vitro models of neuronal VZV latency and reactivation, the limitations of the current systems, and discuss outstanding questions and future directions regarding these processes using these and yet to be developed models. Results obtained from the in vitro models to date will also be discussed in light of the recent data gleaned from studies of VZV latency and gene expression learned from human cadaver ganglia, especially the discovery of VZV latency transcripts that seem to parallel the long-studied latency-associated transcripts of other neurotropic alphaherpesviruses.
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Affiliation(s)
| | - Paul R Kinchington
- Department of Ophthalmology, and Department of Molecular Microbiology and Genetics, University of Pittsburgh, EEI 1020, 203 Lothrop Street, Pittsburgh, PA, 156213, USA.
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Zengeler KE, Lukens JR. Innate immunity at the crossroads of healthy brain maturation and neurodevelopmental disorders. Nat Rev Immunol 2021; 21:454-468. [PMID: 33479477 PMCID: PMC9213174 DOI: 10.1038/s41577-020-00487-7] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2020] [Indexed: 12/29/2022]
Abstract
The immune and nervous systems have unique developmental trajectories that individually build intricate networks of cells with highly specialized functions. These two systems have extensive mechanistic overlap and frequently coordinate to accomplish the proper growth and maturation of an organism. Brain resident innate immune cells - microglia - have the capacity to sculpt neural circuitry and coordinate copious and diverse neurodevelopmental processes. Moreover, many immune cells and immune-related signalling molecules are found in the developing nervous system and contribute to healthy neurodevelopment. In particular, many components of the innate immune system, including Toll-like receptors, cytokines, inflammasomes and phagocytic signals, are critical contributors to healthy brain development. Accordingly, dysfunction in innate immune signalling pathways has been functionally linked to many neurodevelopmental disorders, including autism and schizophrenia. This review discusses the essential roles of microglia and innate immune signalling in the assembly and maintenance of a properly functioning nervous system.
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Affiliation(s)
- Kristine E Zengeler
- Department of Neuroscience, Center for Brain Immunology and Glia (BIG), Charlottesville, VA, USA.
- Neuroscience Graduate Program, Charlottesville, VA, USA.
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA, USA.
| | - John R Lukens
- Department of Neuroscience, Center for Brain Immunology and Glia (BIG), Charlottesville, VA, USA.
- Neuroscience Graduate Program, Charlottesville, VA, USA.
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA, USA.
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Compromised Hippocampal Neuroplasticity in the Interferon-α and Toll-like Receptor-3 Activation-Induced Mouse Depression Model. Mol Neurobiol 2020; 57:3171-3182. [PMID: 32504419 PMCID: PMC7320059 DOI: 10.1007/s12035-020-01927-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 05/01/2020] [Indexed: 12/17/2022]
Abstract
Disrupted neuronal plasticity due to subtle inflammation is considered to play a fundamental role in the pathogenesis of major depressive disorder. Interferon-α (IFN-α) potentiates immune responses against viral pathogens that induce toll-like receptor-3 (TLR3) activation but evokes severe major depressive disorder in humans by mechanisms that remain insufficiently described. By using a previously established mouse model of depression induced by combined delivery of IFN-α and polyinosinic:polycytidylic acid (poly(I:C)), a TLR3 agonist, we provide evidence that IFN-α and poly(I:C) reduce apical dendritic spine density in the hippocampal CA1 area ex vivo via mechanisms involving decreased TrkB signaling. In vitro, IFN-α and poly(I:C) treatments required neuronal activity to reduce dendritic spine density and TrkB signaling. The levels of presynaptic protein vesicular glutamate transporter (VGLUT)-1 and postsynaptic protein postsynaptic density-95 (PSD95) were specifically decreased, whereas the expression of both synaptic and extrasynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor 1 (AMPAR1) was increased by IFN-α and poly(I:C) delivery. Patch clamp recordings in primary hippocampal neurons revealed that morphological changes at the synapse induced by IFN-α and poly(I:C) costimulation were accompanied by an increased action potential threshold and action potential frequency, indicative of impaired neuronal excitability. Taken together, IFN-α and poly(I:C) delivery leads to structural and functional alterations at the synapse indicating that compromised neuroplasticity may play an integral role in the pathogenesis of immune response-induced depression.
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Arnaboldi F, Sommariva M, Opizzi E, Rasile M, Camelliti S, Busnelli M, Menegola E, Di Renzo F, Menon A, Barajon I. Expression of Toll-like receptors 4 and 7 in murine peripheral nervous system development. Ann Anat 2020; 231:151526. [PMID: 32380196 DOI: 10.1016/j.aanat.2020.151526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 02/03/2020] [Accepted: 04/10/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Toll-Like Receptors (TLRs) play a critical role in the innate and adaptive immune system. They are the mammalian orthologs of Drosophila melanogaster protein Toll, which has been proved to have an early morphogenetic role in invertebrate embryogenesis that in the adult switches to an immune function. AIM The aim of this study was to evaluate the expression of TLR4 and TLR7 during dorsal root ganglia (DRG), paravertebral ganglia (PVG), and enteric nervous system (ENS) murine development. METHODS Mouse embryos from different stages (i.e. E12 to E18) were processed for immunolocalization analysis on formalin-fixed paraffin-embedded sections, and isolated intestine were processed for whole-mount preparations. RESULTS We observed a differentially regulated expression of TLR4 and TLR7 during embryogenesis and an overall increased expression of both receptors during development. While TLR4 was detectable in neurons of DRG and PVG starting from E14 and only from E18 in the ENS, TLR7 was already expressed in scattered neurons of all the investigated regions at E12. CONCLUSIONS TLR4 and TRL7 expression temporal patterns suggest a morphogenetic role for these receptors in the development of neural crest derivatives in mammals.
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Affiliation(s)
- Francesca Arnaboldi
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy.
| | - Michele Sommariva
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Emanuela Opizzi
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Marco Rasile
- Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano, Milano, Italy; Humanitas University, Via Rita Levi Montalcini 4, 20090 Pieve Emanuele, Milano, Italy
| | - Simone Camelliti
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Marco Busnelli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti, 9/11/13, 20133 Milano, Italy
| | - Elena Menegola
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Francesca Di Renzo
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Alessandra Menon
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy; Clinica Ortopedica, ASST Centro Specialistico Ortopedico Traumatologico Gaetano Pini-CTO, Milan, Italy
| | - Isabella Barajon
- Humanitas University, Via Rita Levi Montalcini 4, 20090 Pieve Emanuele, Milano, Italy
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Ying Z, Li X, Dang H, Yin N, Gao C. Molecular immune mechanisms of HPV-infected HaCaT cells in vitro based on toll-like receptors signaling pathway. J Clin Lab Anal 2019; 34:e23101. [PMID: 31785031 PMCID: PMC7083446 DOI: 10.1002/jcla.23101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To explore the molecular immune mechanism of HPV-infected HaCaT cells in vitro based on TLRs signaling pathway by analyzing the effects of interfering TLRs on inflammatory and immune factors in the signaling pathway. METHODS FCM was used to analyze the proportion of Th1, Th2, Th17, and Treg cells in blood samples. HPV-infected HaCaT cells were divided into five groups: A, B, C, D, and E. Group A added TLR3 antagonist, group B added TLR9 antagonist, group C added equivalent saline, group D added IRF3 agonist, and group E added IRF3 inhibitor. Immunohistochemistry was used to analyze the expression of TLR3 and TLR9 in HaCaT cell model; ELISA was used to analyze the expression of inflammatory factors IL-2, TNF-a, and IFN-beta; WB was used to analyze the expression of TRAF3, IKK epsilon, and TBK1; RT-PCR was used to analyze the expression of IRF3 and IRF7 in each cell model. RESULTS The proportion of blood immune cells in patients with HPV infection was Th1, Th17, Th2, and Treg, with statistical significance (P < .05); the expression of TLR3 and TLR9 in HPV-infected cells was higher than that in negative control group, with statistical significance (P < .05); TLR3 was higher than TLR9, with no significant difference (P > .05); the expression of IL-2, TNF-alpha, IFN-beta in each group, TLR3, and TLR9 was higher than that in negative control group (P < .05). The expression of TRAF3, IKK epsilon, and TBK1 in the control group was higher than that in the TLR3 and TLR9 inhibitor groups, and the expression of IRF3 and IRF7 in the TLR9 inhibitor group was higher than that in the TLR3 inhibitor group (P < .05); the expression of IRF3 and IRF7 in the TLR3i and TLR9i inhibitor groups was lower than that in the TLR3 inhibitor group (P < .05). Compared with the control group, IRF3a group was higher than the control group, IRF3i group was lower than the control group, the difference was statistically significant (P < .05). CONCLUSION TLR3 and TLR9, the key factors of TLRs, are highly expressed in HaCaT cells infected with HPV. Through TLRs-IKK-e-IRFs-IFN signaling pathway, they can induce high expression of inflammatory factors, IKK-e, IRFs, and IFN, and improve immunity.
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Affiliation(s)
- Zuolin Ying
- Department of Dermatology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaojie Li
- Department of Dermatology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Dang
- Department of Dermatology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Na Yin
- Department of Dermatology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chuang Gao
- Department of Dermatology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Chen CY, Shih YC, Hung YF, Hsueh YP. Beyond defense: regulation of neuronal morphogenesis and brain functions via Toll-like receptors. J Biomed Sci 2019; 26:90. [PMID: 31684953 PMCID: PMC6827257 DOI: 10.1186/s12929-019-0584-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 10/23/2019] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are well known as critical pattern recognition receptors that trigger innate immune responses. In addition, TLRs are expressed in neurons and may act as the gears in the neuronal detection/alarm system for making good connections. As neuronal differentiation and circuit formation take place along with programmed cell death, neurons face the challenge of connecting with appropriate targets while avoiding dying or dead neurons. Activation of neuronal TLR3, TLR7 and TLR8 with nucleic acids negatively modulates neurite outgrowth and alters synapse formation in a cell-autonomous manner. It consequently influences neural connectivity and brain function and leads to deficits related to neuropsychiatric disorders. Importantly, neuronal TLR activation does not simply duplicate the downstream signal pathways and effectors of classical innate immune responses. The differences in spatial and temporal expression of TLRs and their ligands likely account for the diverse signaling pathways of neuronal TLRs. In conclusion, the accumulated evidence strengthens the idea that the innate immune system of neurons serves as an alarm system that responds to exogenous pathogens as well as intrinsic danger signals and fine-tune developmental processes of neurons.
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Affiliation(s)
- Chiung-Ya Chen
- Institute of Molecular Biology, Academia Sinica, 128, Academia Rd., Sec. 2, Taipei, 11529, Taiwan, Republic of China.
| | - Yi-Chun Shih
- Institute of Molecular Biology, Academia Sinica, 128, Academia Rd., Sec. 2, Taipei, 11529, Taiwan, Republic of China
| | - Yun-Fen Hung
- Institute of Molecular Biology, Academia Sinica, 128, Academia Rd., Sec. 2, Taipei, 11529, Taiwan, Republic of China
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, 128, Academia Rd., Sec. 2, Taipei, 11529, Taiwan, Republic of China.
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Aurelian L, Balan I. GABA AR α2-activated neuroimmune signal controls binge drinking and impulsivity through regulation of the CCL2/CX3CL1 balance. Psychopharmacology (Berl) 2019; 236:3023-3043. [PMID: 31030249 DOI: 10.1007/s00213-019-05220-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/04/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Toll-like receptors (TLRs) are a family of innate immune system receptors that respond to pathogen-derived and tissue damage-related ligands and are increasingly recognized for their impact on homeostasis and its dysregulation in the nervous system. TLR signaling participates in brain injury and addiction, but its role in the alcohol-seeking behavior, which initiates alcohol drinking, is still poorly understood. In this review, we discuss our findings designed to elucidate the potential contribution of the activated TLR4 signal located in neurons, on impulsivity and the predisposition to initiate alcohol drinking (binge drinking). RESULTS Our findings indicate that the TLR4 signal is innately activated in neurons from alcohol-preferring subjects, identifying a genetic contribution to the regulation of impulsivity and the alcohol-seeking propensity. Signal activation is through the non-canonical, previously unknown, binding of TLR4 to the α2 subunit of the γ-aminobutyric 2 acid A receptor (GABAAR α2). Activation is sustained by the stress hormone corticotrophin-releasing factor (CRF) and additional still poorly recognized ligand/scaffold proteins. Focus is on the effect of TLR4 signal activation on the balance between pro- and anti-inflammatory chemokines [chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-X3-C motif) ligand 1 (CX3CL1)] and its effect on binge drinking. CONCLUSION The results are discussed within the context of current findings on the distinct activation and functions of TLR signals located in neurons, as opposed to immune cells. They indicate that the balance between pro- and anti-inflammatory TLR4 signaling plays a major role in binge drinking. These findings have major impact on future basic and translational research, including the development of potential therapeutic and preventative strategies.
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Affiliation(s)
- Laure Aurelian
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Stanford University School of Medicine OFDD, Stanford, CA, 94305, USA.
| | - Irina Balan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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13
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Hridi SU, Franssen AJPM, Jiang HR, Bushell TJ. Interleukin-16 inhibits sodium channel function and GluA1 phosphorylation via CD4- and CD9-independent mechanisms to reduce hippocampal neuronal excitability and synaptic activity. Mol Cell Neurosci 2019; 95:71-78. [PMID: 30738184 DOI: 10.1016/j.mcn.2019.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 11/20/2022] Open
Abstract
Interleukin 16 (IL-16) is a cytokine that is primarily associated with CD4+ T cell function, but also exists as a multi-domain PDZ protein expressed within cerebellar and hippocampal neurons. We have previously shown that lymphocyte-derived IL-16 is neuroprotective against excitotoxicity, but evidence of how it affects neuronal function is limited. Here, we have investigated whether IL-16 modulates neuronal excitability and synaptic activity in mouse primary hippocampal cultures. Application of recombinant IL-16 impairs both glutamate-induced increases in intracellular Ca2+ and sEPSC frequency and amplitude in a CD4- and CD9-independent manner. We examined the mechanisms underlying these effects, with rIL-16 reducing GluA1 S831 phosphorylation and inhibiting Na+ channel function. Taken together, these data suggest that IL-16 reduces neuronal excitability and synaptic activity via multiple mechanisms and adds further evidence that alternative receptors may exist for IL-16.
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Affiliation(s)
- Shehla U Hridi
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Aimée J P M Franssen
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Hui-Rong Jiang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Trevor J Bushell
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK.
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Fast Optical Sectioning for Widefield Fluorescence Mesoscopy with the Mesolens based on HiLo Microscopy. Sci Rep 2018; 8:16259. [PMID: 30390029 PMCID: PMC6215018 DOI: 10.1038/s41598-018-34516-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022] Open
Abstract
We present here a fast optical sectioning method for mesoscopy based on HiLo microscopy, which makes possible imaging of specimens of up to 4.4 mm × 3 mm × 3 mm in volume in under 17 hours (estimated for a z-stack comprising 1000 images excluding computation time) with subcellular resolution throughout. Widefield epifluorescence imaging is performed with the Mesolens using a high pixel-number camera capable of sensor-shifting to generate a 259.5 Megapixel image, and we have developed custom software to perform HiLo processing of the very large datasets. Using this method, we obtain comparable sectioning strength to confocal laser scanning microscopy (CLSM), with sections as thin as 6.8 ± 0.2 μm and raw acquisition speed of 1 minute per slice which is up to 30 times faster than CLSM on the full field of view (FOV) of the Mesolens of 4.4 mm with lateral resolution of 0.7 μm and axial resolution of 7 μm. We have applied this HiLo mesoscopy method to image fixed and fluorescently stained hippocampal neuronal specimens and a 5-day old zebrafish larva.
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