Microglial activation in the neurodevelopment: A narrative review

2021 ◽  
Vol 21 ◽  
Author(s):  
Airam Barbosa de Moura ◽  
Morgana Sonza Abitante ◽  
Ritele Hernandez Silva ◽  
João Quevedo ◽  
Gislaine Zilli Réus

: Microglia are immune cells found in the central nervous system (CNS) involved in infection combat and cellular debris clean. These glial cells are involved in synaptogenesis during brain development by their interactions with neurons and other glial cells. These relations are associated with the secretion of signaling molecules, such as chemokines and neurotrophic factors. Microglia cells influence synapsis and neuron morphology during different phases of development. Also, other systems, for example, gut microbiota indirectly affect microglial functions and morphology. Several factors that can occur in different development periods, including intrauterine through adult life, could impact microglia. Impairment in these cells could be associated with the development of some psychiatric conditions, such as schizophrenia, autistic spectrum disorder (ASD), and depression. This review is focusing on describing microglia functions in the maintenance of CNS and how they are associated with other systems, as the gut-microbiota brain axis and environmental stressors, such as stress, maternal deprivation, sleep deprivation, immune activation, and ethanol exposure, that can influence the function of the microglia during neurodevelopment.

Author(s):  
Prithiv K R Kumar

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.


2020 ◽  
Vol 20 (13) ◽  
pp. 1142-1153 ◽  
Author(s):  
Sreyashi Chandra ◽  
Md. Tanjim Alam ◽  
Jhilik Dey ◽  
Baby C. Pulikkaparambil Sasidharan ◽  
Upasana Ray ◽  
...  

Background: The central nervous system (CNS) known to regulate the physiological conditions of human body, also itself gets dynamically regulated by both the physiological as well as pathological conditions of the body. These conditions get changed quite often, and often involve changes introduced into the gut microbiota which, as studies are revealing, directly modulate the CNS via a crosstalk. This cross-talk between the gut microbiota and CNS, i.e., the gut-brain axis (GBA), plays a major role in the pathogenesis of many neurodegenerative disorders such as Parkinson’s disease (PD), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS) and Huntington’s disease (HD). Objective: We aim to discuss how gut microbiota, through GBA, regulate neurodegenerative disorders such as PD, AD, ALS, MS and HD. Methods: In this review, we have discussed the present understanding of the role played by the gut microbiota in neurodegenerative disorders and emphasized the probable therapeutic approaches being explored to treat them. Results: In the first part, we introduce the GBA and its relevance, followed by the changes occurring in the GBA during neurodegenerative disorders and then further discuss its role in the pathogenesis of these diseases. Finally, we discuss its applications in possible therapeutics of these diseases and the current research improvements being made to better investigate this interaction. Conclusion: We concluded that alterations in the intestinal microbiota modulate various activities that could potentially lead to CNS disorders through interactions via the GBA.


2020 ◽  
Vol 19 (7) ◽  
pp. 483-494
Author(s):  
Tyler J. Wenzel ◽  
Evan Kwong ◽  
Ekta Bajwa ◽  
Andis Klegeris

: Glial cells, including microglia and astrocytes, facilitate the survival and health of all cells within the Central Nervous System (CNS) by secreting a range of growth factors and contributing to tissue and synaptic remodeling. Microglia and astrocytes can also secrete cytotoxins in response to specific stimuli, such as exogenous Pathogen-Associated Molecular Patterns (PAMPs), or endogenous Damage-Associated Molecular Patterns (DAMPs). Excessive cytotoxic secretions can induce the death of neurons and contribute to the progression of neurodegenerative disorders, such as Alzheimer’s disease (AD). The transition between various activation states of glia, which include beneficial and detrimental modes, is regulated by endogenous molecules that include DAMPs, cytokines, neurotransmitters, and bioactive lipids, as well as a diverse group of mediators sometimes collectively referred to as Resolution-Associated Molecular Patterns (RAMPs). RAMPs are released by damaged or dying CNS cells into the extracellular space where they can induce signals in autocrine and paracrine fashions by interacting with glial cell receptors. While the complete range of their effects on glia has not been described yet, it is believed that their overall function is to inhibit adverse CNS inflammatory responses, facilitate tissue remodeling and cellular debris removal. This article summarizes the available evidence implicating the following RAMPs in CNS physiological processes and neurodegenerative diseases: cardiolipin (CL), prothymosin α (ProTα), binding immunoglobulin protein (BiP), heat shock protein (HSP) 10, HSP 27, and αB-crystallin. Studies on the molecular mechanisms engaged by RAMPs could identify novel glial targets for development of therapeutic agents that effectively slow down neuroinflammatory disorders including AD.


Author(s):  
Giedre Milinkeviciute ◽  
Karina S. Cramer

The auditory brainstem carries out sound localization functions that require an extraordinary degree of precision. While many of the specializations needed for these functions reside in auditory neurons, additional adaptations are made possible by the functions of glial cells. Astrocytes, once thought to have mainly a supporting role in nervous system function, are now known to participate in synaptic function. In the auditory brainstem, they contribute to development of specialized synapses and to mature synaptic function. Oligodendrocytes play critical roles in regulating timing in sound localization circuitry. Microglia enter the central nervous system early in development, and also have important functions in the auditory system’s response to injury. This chapter highlights the unique functions of these non-neuronal cells in the auditory system.


2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.


2018 ◽  
Vol 218 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Nathaniel Noblett ◽  
Zilu Wu ◽  
Zhao Hua Ding ◽  
Seungmee Park ◽  
Tony Roenspies ◽  
...  

Neuronal morphology and circuitry established during early development must often be maintained over the entirety of animal lifespans. Compared with neuronal development, the mechanisms that maintain mature neuronal structures and architecture are little understood. The conserved disco-interacting protein 2 (DIP2) consists of a DMAP1-binding domain and two adenylate-forming domains (AFDs). We show that the Caenorhabditis elegans DIP-2 maintains morphology of mature neurons. dip-2 loss-of-function mutants display a progressive increase in ectopic neurite sprouting and branching during late larval and adult life. In adults, dip-2 also inhibits initial stages of axon regeneration cell autonomously and acts in parallel to DLK-1 MAP kinase and EFA-6 pathways. The function of DIP-2 in maintenance of neuron morphology and in axon regrowth requires its AFD domains and is independent of its DMAP1-binding domain. Our findings reveal a new conserved regulator of neuronal morphology maintenance and axon regrowth after injury.


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