scholarly journals Microglial replacement in the aged brain restricts neuroinflammation following intracerebral hemorrhage

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiuping Li ◽  
Xiaolin Gao ◽  
Wenyan Zhang ◽  
Mingming Liu ◽  
Zhaoli Han ◽  
...  

AbstractAged microglia display augmented inflammatory activity after neural injury. Although aging is a risk factor for poor outcome after brain insults, the precise impact of aging-related alterations in microglia on neural injury remains poorly understood. Microglia can be eliminated via pharmacological inhibition of the colony–stimulating factor 1 receptor (CSF1R). Upon withdrawal of CSF1R inhibitors, microglia rapidly repopulate the entire brain, leading to replacement of the microglial compartment. In this study, we investigated the impact of microglial replacement in the aged brain on neural injury using a mouse model of intracerebral hemorrhage (ICH) induced by collagenase injection. We found that replacement of microglia in the aged brain reduced neurological deficits and brain edema after ICH. Microglial replacement-induced attenuation of ICH injury was accompanied with alleviated blood-brain barrier disruption and leukocyte infiltration. Notably, newly repopulated microglia had reduced expression of IL-1β, TNF-α and CD86, and upregulation of CD206 in response to ICH. Our findings suggest that replacement of microglia in the aged brain restricts neuroinflammation and brain injury following ICH.

Author(s):  
Ghaith A. Bahadar ◽  
Zahoor A Shah

: There is a surge in diabetes incidence with an estimated 463 million individuals been diagnosed worldwide. Diabetes Mellitus (DM) is a major stroke-related comorbid condition that increases the susceptibility of disabling post-stroke outcomes. Although less common, intracerebral hemorrhage (ICH) is the most dramatic subtype of stroke that is associated with higher mortality, particularly in DM population. Previous studies have focused mainly on the impact of DM on ischemic stroke. Few studies have focused on impact of DM on ICH and discussed the blood-brain barrier disruption, brain edema, and hematoma formation. However, more recently, investigating the role of oxidative damage and reactive oxygen species (ROS) production in preclinical studies involving DM-ICH animal models has gained attention. But, little is known about the correlation between neuroinflammatory processes, glial cells activation, and peripheral immune cell invasion with DM-ICH injury. DM and ICH patients experience impaired abilities in multiple cognitive domains by relatively comparable mechanisms, which could get exacerbated in the setting of comorbidities. In this review, we discuss both the pathology of DM as a comorbid condition for ICH and the potential molecular therapeutic targets for the clinical management of the ICH and its recovery.


2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaohong Wang ◽  
Yin Hong ◽  
Lei Wu ◽  
Xiaochun Duan ◽  
Yue Hu ◽  
...  

This study aims at evaluating the importance and its underlying mechanism of the cluster of microRNA-144/451 (miR-144/451) in the models with intracerebral hemorrhage (ICH). A model of collagenase-induced mice with ICH and a model of mice with simple miR-144/451 gene knockout (KO) were used in this study. Neurodeficits and the water content of the brain of the mice in each group were detected 3 days after collagenase injection. The secretion of proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), as well as certain biomarkers of oxidative stress, was determined in this study. The results revealed that the expression of miR-451 significantly decreased in the mice with ICH, whereas miR-144 showed no significant changes. KO of the cluster of miR-144/451 exacerbated the neurological deficits and brain edema in the mice with ICH. Further analyses demonstrated that the KO of the cluster of miR-144/451 significantly promoted the secretion of TNF-α and IL-1β and the oxidative stress in the perihematomal region of the mice with ICH. In addition, the miR-144/451's depletion inhibited the regulatory axis' activities of miR-451-14-3-3ζ-FoxO3 in the mice with ICH. In conclusion, these data demonstrated that miR-144/451 might protect the mice with ICH against neuroinflammation and oxidative stress by targeting the pathway of miR-451-14-3-3ζ-FoxO3.


2003 ◽  
Vol 99 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Sònia Abilleira ◽  
Joan Montaner ◽  
Carlos A. Molina ◽  
Jasone Monasterio ◽  
José Castillo ◽  
...  

Object. Matrix metalloproteinases (MMPs) are overexpressed in the presence of some neurological diseases in which blood—brain barrier disruption exists. The authors investigated the MMP-9 concentration in patients after acute intracerebral hemorrhage (ICH) and its relation to perihematomal edema (PHE). Methods. Concentrations of MMP-9 and related proteins were determined in plasma by performing an enzyme-linked immunosorbent assay of samples drawn after hospital admission (< 24 hours after stroke) from 57 patients with ICH. The diagnosis of ICH was made on the basis of findings on computerized tomography (CT) scans. The volumes of ICH and PHE were measured on baseline and follow-up CT scans at the same time that the patient's neurological status was assessed using the Canadian Stroke Scale and the Glasgow Coma Scale. Increased expression of MMP-9 was found among patients with ICH. In cases of deep ICH, MMP-9 was significantly associated with PHE volume (r = 0.53; p = 0.01) and neurological worsening (237.4 compared with 111.3 ng/ml MMP-9; p = 0.04). A logistic regression model focusing on the study of absolute PHE volume showed ICH volume as an independent predictor (odds ratio [OR] 3.37; 95% confidence interval [CI] 1.1–10.3; p = 0.03). A second analysis of relative PHE volume (absolute PHE volume/ICH volume) in patients with deep ICH demonstrated that the only factor related to it was MMP-9 concentration (OR 11.6; 95% CI 1.5–89.1; p = 0.018). Conclusions. Expression of MMP-9 is raised after acute spontaneous ICH. Among patients with deep ICH this increase is associated with PHE and the development of neurological worsening within the acute stage.


2019 ◽  
Vol 10 (9) ◽  
pp. 5323-5332 ◽  
Author(s):  
Yu-Sheng Shi ◽  
Yan Zhang ◽  
Bin Liu ◽  
Chun-Bin Li ◽  
Jiao Wu ◽  
...  

Oxidative stress is considered to play an important role in the cerebral ischemia–reperfusion injury.


2021 ◽  
Vol 15 ◽  
Author(s):  
Xichang Liu ◽  
Gang Wu ◽  
Na Tang ◽  
Li Li ◽  
Cuimin Liu ◽  
...  

Objective: The “Glymphatic” system, a network of perivascular tunnels wrapped by astrocyte endfeet, was reported to be closely associated with the diseases of the central nervous system. Here, we investigated the role of the glymphatic system in intracerebral hemorrhage (ICH) and its protective mechanism.Method: Experimental ICH model was induced by type IV collagenase in rats. Cerebral lymphatic blockage was induced by ligation and removal of cervical lymph nodes. The experimental rats were divided into sham-operated (SO) group, ICH group, and cerebral lymphatic blocking and ICH (ICH + CLB) group. Neurological scores were measured using the Garcia scoring system on the third and seventh day after ICH. Active caspase-3 was immunostained to evaluate neuronal apoptosis. Brain water content was calculated using the dry-wet specific gravity method. The expression of inflammatory factors TNF-α, IL-1β, and IL-10 were detected using ELISA. Aquaporins-4 (AQP-4) and glial fibrillary acidic protein (GFAP) were detected using western blot analysis.Results: The neurological scores of rats in the CLB + ICH group were significantly lower than those in the in ICH group. The number of active caspase-3 neurons was significantly higher in the CLB + ICH group compared to the ICH group. CLB significantly aggravated ICH-induced brain edema 3 d after ICH. There was an increase in the expression of TNF-α, IL-1β, IL-10, AQP-4, GFAP after ICH. The expression of TNF-α was significantly higher in the CLB + ICH group compared to ICH group 3 d after ICH while there was no difference 7 d after ICH. There was no statistical difference in the expression of IL-1β between the ICH group and CLB + ICH group. However, the expression of IL-10 in the CLB + ICH group was significantly lower than that in the ICH group. Lastly, AQP-4 expression was significantly lower in the CLB + ICH group compared to the ICH group while the expression of GFAP was higher in the CLB + ICH group compared to the ICH group.Conclusion: CLB exacerbated cerebral edema, neuroinflammation, neuronal apoptosis and caused neurological deficits in rats with ICH via down-regulating AQP-4, up-regulating inflammatory TNF-α and inhibiting IL-10 expression. The glymphatic drainage system protects against neurologic injury after ICH induction in rats under normal physiological conditions.


2020 ◽  
Vol 17 (4) ◽  
pp. 471-479
Author(s):  
Yan Lu ◽  
Zhendong Xu ◽  
Fuyi Shen ◽  
Rong Lin ◽  
Haibing Li ◽  
...  

Background: The Inflammatory cytokine, tumor necrosis factor-α (TNF-α), disrupts blood-brain barrier (BBB). Propofol reportedly exerts an anti-inflammatory effect in the central nervous system. Objective: We hypothesized that propofol could provide a protective effect against TNF-α-induced disruption in human cerebral microvascular endothelial cells (hCMEC/D3 cells) and explored the underlying mechanisms. Methods: The hCMEC/D3 cell monolayers were pretreated with propofol, followed by TNF-α treatment. The integrity of BBB was reflected by assessing the trans-endothelial electrical resistance (TEER) and determining the expression of proteins within tight junctions (TJs). The effect of propofol on TNF-α-modulated nitric oxide production was measured by a nitrate reductase assay kit. The expression of ZO-1, claudin-5, occludin, TNF receptor 1 (TNFR1), TNF receptor 2 (TNFR2), proviral-integration site for Moloney murine leukaemia virus (PIM)-1kinase, the phosphorylation of endothelial nitric oxide synthase at ser633 (peNOS-ser633) were detected by western blot. Results: In hCMEC/D3 cells, TNF-α treatment markedly disrupted the integrity of BBB. Further, we found TNF-α treatment could increase the expression of PIM-1, then activate the phosphorylation of eNOS and induce the release of nitric oxide (NO). More importantly, we found that TNF- α-impaired BBB integrity could be reversed by propofol. Conclusion: These results suggest that the PIM-1/eNOS/NO pathway plays a vital role, in which Propofol protects against TNF-α-induced blood-brain barrier disruption.


Stroke ◽  
2020 ◽  
Vol 51 (2) ◽  
pp. 612-618 ◽  
Author(s):  
Che-Feng Chang ◽  
Jordan Massey ◽  
Artem Osherov ◽  
Luís Henrique Angenendt da Costa ◽  
Lauren H. Sansing

Background and Purpose— Enhancement of erythrophagocytosis by macrophages in a timely manner can limit the toxic effects of erythrocyte metabolites and promote brain recovery after intracerebral hemorrhage (ICH). In the current study, we investigated the therapeutic effect of retinoid X receptor agonist, bexarotene, in facilitating erythrophagocytosis and neurobehavioral recovery in 2 mouse models of ICH. Methods— Bone marrow-derived macrophages and fluorescently labeled erythrocytes were used to study erythrophagocytosis in vitro with phenotypic changes quantified by gene expression. ICH was modeled in vivo using intrastriatal autologous blood and collagenase injection in mice with and without bexarotene treatment beginning 3 hours after ICH. In vivo phagocytosis, ability and hematoma clearance were evaluated by erythrophagocytosis assays, flow cytometry, and histological analysis. Neurological deficits and functional recovery were also quantified. Results— Bexarotene increased macrophage expression of phagocytosis receptors and erythrophagocytosis and reduced macrophage TNF (tumor necrosis factor) production in vitro. In vivo, bexarotene treatment enhanced erythrophagocytosis, reduced hematoma volume, and ultimately improved neurological recovery after ICH in 2 distinct models of ICH. Conclusions— Bexarotene administration is beneficial for recovery after ICH by enhancing hemorrhage phagocytosis, modulating macrophage phenotype, and improving functional recovery.


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