Xuesaitong May Protect Against Ischemic Stroke by Modulating Microglial Phenotypes and Inhibiting Neuronal Cell Apoptosis via the STAT3 Signaling Pathway

2019 ◽  
Vol 18 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Fangfang Li ◽  
Haiping Zhao ◽  
Ziping Han ◽  
Rongliang Wang ◽  
Zhen Tao ◽  
...  

Background: Xuesaitong mainly comprises Panax notoginseng saponins and has shown a promising feature in an acute ischemic stroke model; however, its effect on long-term recovery following stroke, and the related mechanisms, are unknown. Methods: The objective of this study was to investigate the long-term protective effects of xuesaitong against ischemic stroke and its effect on microglial polarization. Experimental cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 45 min, and C57BL/6 mice were immediately injected with xuesaitong or vehicle through the caudal vein at the onset of cerebral reperfusion consecutively for 14 days. The animals were randomly divided into three groups: a sham-operated group, vehicle-treated group and xuesaitong-treated group at a dose of 15μg/g. Subsequently, 2,3,5-triphenyltetrazolium chloride staining was used to assess infarct volume, and adhesive removal tests and balance beam tests were used to evaluate neurological deficits at days 1, 3, 7 and 14 following ischemia. Reverse-transcriptase polymerase chain reaction and immunofluorescence staining for M1 markers (CD16, iNOS) and M2 markers (CD206, arginase-1) were performed to characterize phenotypic changes in microglia. Elisa was used to determine the release of pro-inflammatory and anti-inflammatory cytokines. TUNEL staining was conducted to detect neuronal cell apoptosis, and western blots were used to determine the activation of signal transducer and activator of transcription 3 (STAT3). Results: Our results revealed that xuesaitong treatment, compared with vehicle treatment, significantly reduced cerebral infarct volume 1 and 3 days after MCAO and resulted in significant improvements in long-term neurological outcomes. Furthermore, xuesaitong treatment, compared with vehicle treatment, significantly reduced M1 markers and elevated M2 markers 7 and 14 days after MCAO at both the mRNA and protein level in ipsilateral brain tissue. This finding was also accompanied by a reduction in neuronal cell apoptosis and p-STAT3 transcription factor levels in the xuesaitong-treated group compared with the vehicle-treated group. Conclusion: We demonstrated that xuesaitong has long-term neuroprotective effects against ischemic stroke, possibly by promoting the polarization of microglia to an M2 phenotype and by inhibiting neuronal cell death via down-regulation of the STAT3 signaling pathway, providing new evidence that xuesaitong might be a promising therapeutic strategy for ischemic stroke.

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ahlem Zaghmi ◽  
Antonio Dopico-López ◽  
María Pérez-Mato ◽  
Ramón Iglesias-Rey ◽  
Pablo Hervella ◽  
...  

AbstractStroke is a major cause of morbidity, mortality, and disability. During ischemic stroke, a marked and prolonged rise of glutamate concentration in the brain causes neuronal cell death. This study explores the protective effect of a bioconjugate form of glutamate oxaloacetate transaminase (hrGOT), which catalyzes the depletion of blood glutamate in the bloodstream for ~6 days following a single administration. When treated with this bioconjugate, a significant reduction of the infarct volume and a better retention of sensorimotor function was observed for ischemic rats compared to those treated with saline. Moreover, the equivalent dose of native hrGOT yielded similar results to the saline treated group for some tests. Targeting the bioconjugate to the blood-brain-barrier did not improve its performance. The data suggest that the bioconjugates draw glutamate out of the brain by displacing homeostasis between the different glutamate pools of the body.


2021 ◽  
Author(s):  
Dandan Zhang ◽  
Shengnan Zhao ◽  
Zhijie Zhang ◽  
Danfeng Xu ◽  
Di Lian ◽  
...  

Abstract Background: Streptococcus pneumoniae meningitis is a destructive central nervous system (CNS) infection with acute and long-term neurological disorders. Compelling evidence provided by previous studies suggests that p75NTR signaling influences cell survival, apoptosis, and proliferation in brain-injured conditions. However, the role of p75NTR signaling in regulating pneumococcal meningitis (PM)-induced neuroinflammation and altered neurogenesis remains largely to be elucidated.Methods: p75NTR signaling activation in the pathological process of PM was assessed. During acute PM, a small-molecule p75NTR modulator LM11A-31 or vehicle was intranasally administered for 3 days prior to S.pneumoniae exposure. At 24h post-infection, clinical severity, histopathology, astrocytes/microglia activation, neuronal cell apoptosis and death, inflammation-related transcription factors and inflammatory factors were evaluated. Additionally, p75NTR was knocked down by the adenovirus-mediated short-hairpin RNA (shRNA) to ascertain the role of p75NTR in PM. During long-term PM, the intranasal administration of LM11A-31 or vehicle was continued for 7 days after successfully establishing the PM model. Hippocampal neurogenesis was evaluated by double-labeling immunofluorescence with EdU, DCX and NeuN. Results: Our results revealed that both 24h (acute) and 7,14,28day (long-term) groups of infected rats demonstrated increased p75NTR expression in the brain. During acute PM, modulation of p75NTR through pretreatment of PM model with LM11A-31 significantly alleviated S.pneumoniae-induced clinical severity, histopathological injury and the activation of astrocytes and microglia. LM11A-31 pretreatment also significantly ameliorated neuronal cell apoptosis and death. Moreover, we found that blocking p75NTR with LM11A-31 decreased the expression of inflammation-related transcription factors (NF-κBp65, C/EBPβ) and proinflammatory cytokine (IL-1β, TNF-α, IL-6 and iNOS) in the cortex and hippocampus. Furthermore, p75NTR knockdown induced significant changes in histopathology and inflammation-related transcription factors expression. Importantly, combined LM11A-31 adjuvant therapy significantly improved hippocampal neurogenesis.Conclusion: Our findings suggest that the p75NTR signaling plays an essential role in the pathogenesis of PM. Targeting p75NTR has benefit effects on PM rats by alleviating neuroinflammation and promoting hippocampal neurogenesis. Thus, the p75NTR signaling may be a potential therapeutic target to improve the outcome of PM.


2018 ◽  
Vol 55 (9) ◽  
pp. 7153-7163 ◽  
Author(s):  
Youngchul Kim ◽  
Young Seo Kim ◽  
Hyun Young Kim ◽  
Min-Young Noh ◽  
Ji Young Kim ◽  
...  

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1097
Author(s):  
Bhakta Prasad Gaire ◽  
Arjun Sapkota ◽  
Ji Woong Choi

Stroke is a leading cause of death. Stroke survivors often suffer from long-term functional disability. This study demonstrated neuroprotective effects of BMS-986020 (BMS), a selective lysophosphatidic acid receptor 1 (LPA1) antagonist under clinical trials for lung fibrosis and psoriasis, against both acute and sub-acute injuries after ischemic stroke by employing a mouse model with transient middle cerebral artery occlusion (tMCAO). BMS administration immediately after reperfusion significantly attenuated acute brain injuries including brain infarction, neurological deficits, and cell apoptosis at day 1 after tMCAO. Neuroprotective effects of BMS were preserved even when administered at 3 h after reperfusion. Neuroprotection by BMS against acute injuries was associated with attenuation of microglial activation and lipid peroxidation in post-ischemic brains. Notably, repeated BMS administration daily for 14 days after tMCAO exerted long-term neuroprotection in tMCAO-challenged mice, as evidenced by significantly attenuated neurological deficits and improved survival rate. It also attenuated brain tissue loss and cell apoptosis in post-ischemic brains. Mechanistically, it significantly enhanced neurogenesis and angiogenesis in injured brains. A single administration of BMS provided similar long-term neuroprotection except survival rate. Collectively, BMS provided neuroprotection against both acute and sub-acute injuries of ischemic stroke, indicating that BMS might be an appealing therapeutic agent to treat ischemic stroke.


2017 ◽  
Vol 44 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Xiao-Lei Wang ◽  
Chun-Mei Qiao ◽  
Jiong-Ou Liu ◽  
Chun-Yang Li

Background: The present study aims to investigate the protective effects of the SOCS1-JAK2-STAT3 signaling pathway on neurons in a rat model of ischemic stroke. Methods: Our study was conducted using an ischemic stroke rat model. After the microglia were extracted, 40 neonatal Sprague-Dawley (SD) rats were assigned into the blank, AG490, model and negative control (NC) groups. The neurological function of all the rats was evaluated. Histopathological changes were observed. qRT-PCR and western blotting were applied to measure the expression of genes and proteins in the SOCS1-JAK2-STAT3 signaling pathway and related to apoptosis. The TUNEL assay was conducted to calculate the cellular morphology and apoptosis of neuronal cells. Cell viability was detected using the MTT assay. In addition, immunoassays were used to measure the content of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) as well as the levels of oxidative stress. Results: Compared with the blank group, the model and NC groups showed higher neurological function scores—the cytoplasm of the neurons were cavitated, the organelles were reduced with unclear margins, some of the neurons were necrotic, and apoptosis was increased. In addition, the NC and model groups exhibited decreased cell viability, lower mRNA and protein expression of SOCS1 SOCS3 and bcl-2 and reduced SOD and GSH levels but higher mRNA and protein expression levels of AK2, STAT3,Bax and caspase-3 as well as increased protein expression of P-JAK2, P-STAT3 and activated caspase-3 (c-caspase-3). Moreover, the MDA levels were up-regulated in the NC and model groups. In contrast, opposing trends were found in the AG490 group compared with the NC and model groups. Conclusion: These data demonstrate that inhibiting the SOCS1-JAK2-STAT3 signaling pathway can reduce the loss of nerve function and apoptosis of neuronal cells, which provides a new target for the clinical treatment of ischemic stroke.


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