Origin and Emergence of Microglia in the CNS—An Interesting (Hi)story of an Eccentric Cell

Microglia belong to tissue-resident macrophages of the central nervous system (CNS), representing the primary innate immune cells. This cell type constitutes ~7% of non-neuronal cells in the mammalian brain and has a variety of biological roles integral to homeostasis and pathophysiology from the la...

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Bibliographic Details
Main Authors: Iasonas Dermitzakis, Maria Eleni Manthou, Soultana Meditskou, Marie-Ève Tremblay, Steven Petratos, Lida Zoupi, Marina Boziki, Evangelia Kesidou, Constantina Simeonidou, Paschalis Theotokis
Format: Article
Language:English
Published: MDPI AG 2023-03-01
Series:Current Issues in Molecular Biology
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Online Access:https://www.mdpi.com/1467-3045/45/3/171
Description
Summary:Microglia belong to tissue-resident macrophages of the central nervous system (CNS), representing the primary innate immune cells. This cell type constitutes ~7% of non-neuronal cells in the mammalian brain and has a variety of biological roles integral to homeostasis and pathophysiology from the late embryonic to adult brain. Its unique identity that distinguishes its “glial” features from tissue-resident macrophages resides in the fact that once entering the CNS, it is perennially exposed to a unique environment following the formation of the blood–brain barrier. Additionally, tissue-resident macrophage progenies derive from various peripheral sites that exhibit hematopoietic potential, and this has resulted in interpretation issues surrounding their origin. Intensive research endeavors have intended to track microglial progenitors during development and disease. The current review provides a corpus of recent evidence in an attempt to disentangle the birthplace of microglia from the progenitor state and underlies the molecular elements that drive microgliogenesis. Furthermore, it caters towards tracking the lineage spatiotemporally during embryonic development and outlining microglial repopulation in the mature CNS. This collection of data can potentially shed light on the therapeutic potential of microglia for CNS perturbations across various levels of severity.
ISSN:1467-3037
1467-3045