Function of Astrocytes in Neuroprotection and Repair after Ischemic Stroke

Abstract

<b><i>Background:</i></b> Astrocytes are the most numerous cell types within the central nervous system, and many efforts have been put into determining the exact role of astrocytes in neuroprotection and repair after ischemic stroke. Although numerous studies have been done in recent years, there is still no thorough understanding of the exact function of astrocytes in the whole course of the stroke. <b><i>Summary:</i></b> According to the recent literature, there are many structures and factors that play important roles in the process of ischemic stroke, among which blood-brain barrier, various growth factors, gap junctions, AQP4, and glial scars have been studied most comprehensively, and all these factors are closely related to astrocytes. The role of astrocytes in ischemic stroke, therefore, can be analyzed more comprehensively. <b><i>Key Message:</i></b> The present review mainly summarized the current knowledge about astrocytes and their potential roles after ischemic stroke.

CNS Drug Delivery in Stroke: Improving Therapeutic Translation From the Bench to the Bedside

“…28 The ECM of the endothelial cell basement membrane, formed by the exocytosis of collagens, fibronectin, proteoglycans, and laminin, facilitates the interaction between neighboring astrocytes, pericytes, and tight junctions while anchoring the vascular endothelium. [29][30][31] In addition to paracrine signaling, pericytes contribute to the regulation of cerebral blood flow by modifying vascular diameter, shunting blood flow via vasoconstriction or vasodilation in a regionally specific manner. [32][33][34] This is critical because cerebral blood flow and resultant fluid shear stress are required for the maintenance of the BBB phenotype.…”

“…43,44 Dysregulated blood flow resulting from injury to pericytes and secretion of mediators from activated astrocytes can also contribute to BBB dysfunction in stroke by promoting oxidative stress and subsequent endothelial apoptosis. 31,45 Compounding barrier disruption, brain resident microglia are activated and release proinflammatory mediators (ie, interleukin-1β, interleukin-6, TNF-α [tumor necrosis factor-alpha], NO) that increase peripheral immune cell infiltration and promote prolonged BBB impairment. 46,47 Changes to the NVU, inflammation, ECM modification, and subsequent formation of a glial scar by activated astrocytes render predictability of CNS drug delivery difficult, a considerable challenge in the utilization of cytoprotective treatments for stroke.…”

DCs- IL2 Necessary for Glucocorticoids Which Necessary for Interferons Synthesis and Serotonin Synthesis then Promote Ang2- At2 and VEGF-A for Anti-Inflammatory Growth

“…VEGF Biosynthesis also known as a vascular permeability factor in which is a multifunctional active protein structure that is involved in angiogenesis, inflammation, cancer [27]. Astrocytes functions to facilitate and accelerate the proliferation and neural differentiation of BMSCs, through changing and improve inflammatory molecules for producing Beta-subunit upon synthase function which activate astrocytes at different phase after CNS injuries.…”

Astrocyte-Derived Extracellular Vesicles for Ischemic Stroke: Therapeutic Potential and Prospective

“…Stroke is a devastating disease caused by acute local injury of vascular in the brain [ 1 ]. According to statistics, stroke accounts for the second largest cause of death in the world [ 2 ], and 17% of people will experience stroke in his life, and 10% of them will die because of stroke [ 3 , 4 ]. Stroke is mainly divided into two main types: ischemic stroke and hemorrhagic stroke [ 5 ].…”