scholarly journals Microbial Infections Are a Risk Factor for Neurodegenerative Diseases

2021 ◽  
Vol 15 ◽  
Author(s):  
Sarah K. Lotz ◽  
Britanie M. Blackhurst ◽  
Katie L. Reagin ◽  
Kristen E. Funk
Keyword(s):  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Immune Cells ◽  
Disease Process ◽  
Cellular Mechanisms ◽  
Microbial Infections ◽  
The Central Nervous System ◽  
Nervous System Function ◽  
Peripheral Immune Cells

Neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis, comprise a family of disorders characterized by progressive loss of nervous system function. Neuroinflammation is increasingly recognized to be associated with many neurodegenerative diseases but whether it is a cause or consequence of the disease process is unclear. Of growing interest is the role of microbial infections in inciting degenerative neuroinflammatory responses and genetic factors that may regulate those responses. Microbial infections cause inflammation within the central nervous system through activation of brain-resident immune cells and infiltration of peripheral immune cells. These responses are necessary to protect the brain from lethal infections but may also induce neuropathological changes that lead to neurodegeneration. This review discusses the molecular and cellular mechanisms through which microbial infections may increase susceptibility to neurodegenerative diseases. Elucidating these mechanisms is critical for developing targeted therapeutic approaches that prevent the onset and slow the progression of neurodegenerative diseases.

scholarly journals The Role of Metals in Neurodegenerative Diseases of the Central Nervous System

2020 ◽  
Vol 8 (2) ◽  
pp. 130-146
Author(s):  
Afshin Montazeri ◽  
Milad Akhlaghi ◽  
Ahmad Reza Barahimi ◽  
Ali Jahanbazi Jahan Abad ◽  
Reza Jabbari ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
The Central Nervous System

scholarly journals What Guides Peripheral Immune Cells into the Central Nervous System?

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2041
Author(s):  
Theresa Greiner ◽  
Markus Kipp
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune Cells ◽  
Progressive Disease ◽  
Demyelinating Disease ◽  
Disease Stage ◽  
Secondary Progressive ◽  
Relapsing Remitting ◽  
The Central Nervous System ◽  
Peripheral Immune Cells

Multiple sclerosis (MS), an immune-mediated demyelinating disease of the central nervous system (CNS), initially presents with a relapsing-remitting disease course. During this early stage of the disease, leukocytes cross the blood–brain barrier to drive the formation of focal demyelinating plaques. Disease-modifying agents that modulate or suppress the peripheral immune system provide a therapeutic benefit during relapsing-remitting MS (RRMS). The majority of individuals with RRMS ultimately enter a secondary progressive disease stage with a progressive accumulation of neurologic deficits. The cellular and molecular basis for this transition is unclear and the role of inflammation during the secondary progressive disease stage is a subject of intense and controversial debate. In this review article, we discuss the following main hypothesis: during both disease stages, peripheral immune cells are triggered by CNS-intrinsic stimuli to invade the brain parenchyma. Furthermore, we outline the different neuroanatomical routes by which peripheral immune cells might migrate from the periphery into the CNS.

scholarly journals The Role of Microglia during West Nile Virus Infection of the Central Nervous System

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 485 ◽  
Author(s):  
Sarah Stonedahl ◽  
Penny Clarke ◽  
Kenneth L. Tyler
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
West Nile Virus ◽  
Immune Cells ◽  
Neuronal Cell ◽  
The United States ◽  
Health Concern ◽  
West Nile ◽  
The Central Nervous System

Encephalitis resulting from viral infections is a major cause of hospitalization and death worldwide. West Nile Virus (WNV) is a substantial health concern as it is one of the leading causes of viral encephalitis in the United States today. WNV infiltrates the central nervous system (CNS), where it directly infects neurons and induces neuronal cell death, in part, via activation of caspase 3-mediated apoptosis. WNV infection also induces neuroinflammation characterized by activation of innate immune cells, including microglia and astrocytes, production of inflammatory cytokines, breakdown of the blood-brain barrier, and infiltration of peripheral leukocytes. Microglia are the resident immune cells of the brain and monitor the CNS for signs of injury or pathogens. Following infection with WNV, microglia exhibit a change in morphology consistent with activation and are associated with increased expression of proinflammatory cytokines. Recent research has focused on deciphering the role of microglia during WNV encephalitis. Microglia play a protective role during infections by limiting viral growth and reducing mortality in mice. However, it also appears that activated microglia are triggered by T cells to mediate synaptic elimination at late times during infection, which may contribute to long-term neurological deficits following a neuroinvasive WNV infection. This review will discuss the important role of microglia in the pathogenesis of a neuroinvasive WNV infection. Knowledge of the precise role of microglia during a WNV infection may lead to a greater ability to treat and manage WNV encephalitis.

scholarly journals Role of Macrophages and Microglia in Zebrafish Regeneration

2020 ◽  
Vol 21 (13) ◽  
pp. 4768 ◽  
Author(s):  
Susanna R. Var ◽  
Christine A. Byrd-Jacobs
Keyword(s):  
Nervous System ◽  
Immune Cells ◽  
Immune Cell ◽  
Innate Immune ◽  
Inflammatory Processes ◽  
The Central Nervous System ◽  
And Function ◽  
High Degree ◽  
Human Nerve

Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.

scholarly journals Role of the Extracellular Traps in Central Nervous System

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinyan Wu ◽  
Hanhai Zeng ◽  
Lingxin Cai ◽  
Gao Chen
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
Immune Cells ◽  
Brain Barrier ◽  
Extracellular Traps ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Extracellular Trap

It has been reported that several immune cells can release chromatin and granular proteins into extracellular space in response to the stimulation, forming extracellular traps (ETs). The cells involved in the extracellular trap formation are recognized including neutropils, macrophages, basophils, eosinophils, and mast cells. With the development of research related to central nervous system, the role of ETs has been valued in neuroinflammation, blood–brain barrier, and other fields. Meanwhile, it has been found that microglial cells as the resident immune cells of the central nervous system can also release ETs, updating the original understanding. This review aims to clarify the role of the ETs in the central nervous system, especially in neuroinflammation and blood–brain barrier.

scholarly journals Metallothionein in Brain Disorders

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Daniel Juárez-Rebollar ◽  
Camilo Rios ◽  
Concepción Nava-Ruíz ◽  
Marisela Méndez-Armenta
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Neurological Disorders ◽  
Regulation Of Gene Expression ◽  
Main Function ◽  
Brain Disorders ◽  
Essential Metals ◽  
The Central Nervous System

Metallothioneins are a family of proteins which are able to bind metals intracellularly, so their main function is to regulate the cellular metabolism of essential metals. There are 4 major isoforms of MTs (I–IV), three of which have been localized in the central nervous system. MT-I and MT-II have been localized in the spinal cord and brain, mainly in astrocytes, whereas MT-III has been found mainly in neurons. MT-I and MT-II have been considered polyvalent proteins whose main function is to maintain cellular homeostasis of essential metals such as zinc and copper, but other functions have also been considered: detoxification of heavy metals, regulation of gene expression, processes of inflammation, and protection against free radicals generated by oxidative stress. On the other hand, the MT-III has been related in events of pathogenesis of neurodegenerative diseases such as Parkinson and Alzheimer. Likewise, the participation of MTs in other neurological disorders has also been reported. This review shows recent evidence about the role of MT in the central nervous system and its possible role in neurodegenerative diseases as well as in brain disorders.

scholarly journals Role of Connexins 30, 36, and 43 in Brain Tumors, Neurodegenerative Diseases, and Neuroprotection

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 846 ◽  
Author(s):  
Oscar F. Sánchez ◽  
Andrea V. Rodríguez ◽  
José M. Velasco-España ◽  
Laura C. Murillo ◽  
Jhon-Jairo Sutachan ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Posttranslational Modifications ◽  
Cell Communication ◽  
Normal Function ◽  
Epigenetic Mechanisms ◽  
Communication Processes ◽  
The Central Nervous System

Gap junction (GJ) channels and their connexins (Cxs) are complex proteins that have essential functions in cell communication processes in the central nervous system (CNS). Neurons, astrocytes, oligodendrocytes, and microglial cells express an extraordinary repertory of Cxs that are important for cell to cell communication and diffusion of metabolites, ions, neurotransmitters, and gliotransmitters. GJs and Cxs not only contribute to the normal function of the CNS but also the pathological progress of several diseases, such as cancer and neurodegenerative diseases. Besides, they have important roles in mediating neuroprotection by internal or external molecules. However, regulation of Cx expression by epigenetic mechanisms has not been fully elucidated. In this review, we provide an overview of the known mechanisms that regulate the expression of the most abundant Cxs in the central nervous system, Cx30, Cx36, and Cx43, and their role in brain cancer, CNS disorders, and neuroprotection. Initially, we focus on describing the Cx gene structure and how this is regulated by epigenetic mechanisms. Then, the posttranslational modifications that mediate the activity and stability of Cxs are reviewed. Finally, the role of GJs and Cxs in glioblastoma, Alzheimer’s, Parkinson’s, and Huntington’s diseases, and neuroprotection are analyzed with the aim of shedding light in the possibility of using Cx regulators as potential therapeutic molecules.

scholarly journals A Novel Tmem119-tdTomato Reporter Mouse Model for Studying Microglia in the Central Nervous System

2019 ◽  
Author(s):  
Chunsheng Ruan ◽  
Linlin Sun ◽  
Alexandra Kroshilina ◽  
Lien Beckers ◽  
Philip L. De Jager ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Flow Cytometry ◽  
Nervous System ◽  
Mouse Model ◽  
Immune Cells ◽  
Exon 2 ◽  
Reporter Mouse ◽  
The Central Nervous System ◽  
Health And Disease

AbstractMicroglia are resident immune cells of the central nervous system (CNS). The exact role of microglia in the physiopathology of CNS disorders is not clear due to lack of tools to discriminate between CNS resident and infiltrated innate immune cells. Here, we present a novel reporter mouse model targeting a microglia-specific marker (TMEM119) for studying the function of microglia in health and disease. By placing a reporter cassette (GSG-3xFlag-P2A-tdTomato) between the coding sequence of exon 2 and 3’UTR of the Tmem119 gene using CRISPR/Cas9 technology, we generated a Tmem119-tdTomato knock-in mouse strain. Gene expression assay showed no difference of endogenous Tmem119 mRNA level in the CNS of Tmem119tdTomato/+ relative to control Wild-type mice. The cells expressing tdTomato-were recognized by immunofluorescence staining using commercially available anti-TMEM119 antibodies. Using immunofluorescence and flow cytometry techniques, tdTomato+ cells were detected throughout the CNS, but not in peripheral tissues of adult Tmem119tdTomato/+ mice. In addition, aging does not seem to influence TMEM119 expression as tdTomato+ cells were detectable in the CNS of older mice (300 and 540 days old). Further immunofluorescence characterization shows that the tdTomato+ cells were highly colocalized with Iba1+ cells (microglia and macrophages) in the brain, but not with NeuN- (neurons), GFAP- (astrocytes) or Olig2- (oligodendrocytes) labeled cells. Moreover, flow cytometry analysis of brain tissues of adult mice demonstrates that the majority of microglial CD45lowCD11b+ cells (96.6%) are tdTomato positive. Functionally, using a laser-induced injury model, we measured time-lapse activation of tdTomato-labeled microglia by transcranial two-photon microscopy in live Tmem119tdTomato/+ mice. Taken together, the Tmem119-tdTomato reporter mouse model will serve as a valuable tool to specifically study the role of microglia in health and disease.

scholarly journals The Implication of Reticulons (RTNs) in Neurodegenerative Diseases: From Molecular Mechanisms to Potential Diagnostic and Therapeutic Approaches

2021 ◽  
Vol 22 (9) ◽  
pp. 4630
Author(s):  
Agnieszka Kulczyńska-Przybik ◽  
Piotr Mroczko ◽  
Maciej Dulewicz ◽  
Barbara Mroczko
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Molecular Mechanisms ◽  
Therapeutic Approaches ◽  
Cord Injury ◽  
The Central Nervous System ◽  
Pleiotropic Functions ◽  
Lateral Sclerosis

Reticulons (RTNs) are crucial regulatory factors in the central nervous system (CNS) as well as immune system and play pleiotropic functions. In CNS, RTNs are transmembrane proteins mediating neuroanatomical plasticity and functional recovery after central nervous system injury or diseases. Moreover, RTNs, particularly RTN4 and RTN3, are involved in neurodegeneration and neuroinflammation processes. The crucial role of RTNs in the development of several neurodegenerative diseases, including Alzheimer’s disease (AD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or other neurological conditions such as brain injury or spinal cord injury, has attracted scientific interest. Reticulons, particularly RTN-4A (Nogo-A), could provide both an understanding of early pathogenesis of neurodegenerative disorders and be potential therapeutic targets which may offer effective treatment or inhibit disease progression. This review focuses on the molecular mechanisms and functions of RTNs and their potential usefulness in clinical practice as a diagnostic tool or therapeutic strategy.

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