scholarly journals OTULIN is a New Target for EA Treatment in Alleviating Brain Injury and The Activation of Glial Cells By Depressing NF-κB Signalling Pathway in Acute Ischaemic Stroke Rats

2021 ◽  
Author(s):  
Hongbei Xu ◽  
You Wang ◽  
Yong Luo
Keyword(s):  
Brain Injury ◽  
Ischaemic Stroke ◽  
Glial Cells ◽  
Acute Ischaemic Stroke ◽  
Nuclear Translocation ◽  
Infarct Volume ◽  
Cerebral Infarct ◽  
Signalling Pathway ◽  
Negative Regulator ◽  
Tnf Α

Abstract Objective: Ovarian tumour domain deubiquitinase with linear linkage specificity (OTULIN), a potent negative regulator of nuclear factor-κB (NF-κB) signalling pathway, exerted strong neuroprotective role following acute ischemic stroke. Electroacupuncture (EA) is an effective adjuvant treatment for reducing brain injury and neuroinflammtion through inhibiting the nuclear translocation of NF-κB p65, while the underlying mechanism remains unclear. This study investigated whether OTULIN was necessary for EA to mitigate brain injury and the activation of glial cells, following by a transient middle cerebral artery occlusion (tMCAO) model in rats.Methods: Acute ischaemic stroke model was established by performing tMCAO surgery in Sprague-Dawley (SD) rats. EA was performed once daily at “Baihui (GV 20)”, “Hegu (LI 4)”, and “Taichong (LR 3)” acupoints. EA’s effect on the spatiotemporal expression of OTULIN in the ischaemic penumbra of cerebral cortex was detected within 7 d after reperfusion. Following gene interference to silence OTULIN expression, the effects of OTULIN on EA neurological deficits, cerebral infarct volume, neuronal damage, the activation of microglia and astrocytes, the contents of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), and the expression of p-IκBa, IκBa and nucleus/cytoplasm NF-κB p65 protein were assessed. Results: EA treatment increased endogenous OTULIN expression, with a peak at 48 h. Enhanced OTULIN was mainly located in neurons, and little OTULIN was detected in microglia as well. OTULIN silencing obviously reversed EA neuroprotection as demonstrated by worsened neurobehavioural performance, cerebral infarct volume and neuronal injury. Besides, the inhibitory effect of EA on NF-κB pathway was also attenuated by enhanced IκBα phosphorylation and NF-κB p65 nuclear translocation. Furthermore, EA partly inhibited the transformation of microglia and astrocytes to from resting states to activated states, and reduced the secretion of TNF-α, IL-1β and IL-6, but this preventive effects were reversed after silencing OTULIN expression. Conclusions: OTULIN provides a new potential therapeutic target for EA to alleviate acute ischaemic stroke induced brain injury and the activation of glial cells, which is related to depression of NF-κB signalling pathway.

scholarly journals OTULIN is a new target of EA treatment in the alleviation of brain injury and glial cell activation via suppression of the NF-κB signalling pathway in acute ischaemic stroke rats

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Hongbei Xu ◽  
You Wang ◽  
Yong Luo
Keyword(s):  
Brain Injury ◽  
Ischaemic Stroke ◽  
Glial Cell ◽  
Acute Ischaemic Stroke ◽  
Cell Activation ◽  
Nuclear Translocation ◽  
Infarct Volume ◽  
Signalling Pathway ◽  
Glial Cell Activation ◽  
Tnf Α

Abstract Objective Ovarian tumour domain deubiquitinase with linear linkage specificity (OTULIN) is a potent negative regulator of the nuclear factor-κB (NF-κB) signalling pathway, and it plays a strong neuroprotective role following acute ischemic stroke. Electroacupuncture (EA) is an effective adjuvant treatment for reducing brain injury and neuroinflammation via the inhibition of NF-κB p65 nuclear translocation, but the underlying mechanism is not clear. The present study investigated whether OTULIN was necessary for EA to mitigate brain injury and glial cell activation in a transient middle cerebral artery occlusion (tMCAO) model in rats. Methods An acute ischaemic stroke model was established via tMCAO surgery in Sprague–Dawley (SD) rats. EA was performed once daily at “Baihui (GV 20)”, “Hegu (LI 4)”, and “Taichong (LR 3)” acupoints. The effect of EA on the spatiotemporal expression of OTULIN in the ischaemic penumbra of the cerebral cortex was detected within 7 days after reperfusion. The effects of OTULIN gene silencing on EA neurological deficits, cerebral infarct volume, neuronal damage, the activation of microglia and astrocytes, the contents of tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), and the expression of p-IκBa, IκBa and nucleus/cytoplasm NF-κB p65 protein were assessed. Results EA treatment increased endogenous OTULIN expression, which peaked at 48 h. Enhanced OTULIN was primarily located in neurons, but a small amount of OTULIN was detected in microglia. OTULIN silencing obviously reversed EA neuroprotection, which was demonstrated by worsened neurobehavioural performance, cerebral infarct volume and neuronal injury. The inhibitory effect of EA on the NF-κB pathway was also attenuated by enhanced IκBα phosphorylation and NF-κB p65 nuclear translocation. EA partially inhibited the transformation of microglia and astrocytes from resting states to activated states and reduced the secretion of TNF-α, IL-1β and IL-6. However, these preventive effects were reversed after the silencing of OTULIN expression. Conclusions OTULIN provides a new potential therapeutic target for EA to alleviate acute ischaemic stroke-induced brain injury and the activation of glial cells, which are related to suppression of the NF-κB signalling pathway.

scholarly journals Immuno-inflammatory activation in acute cardio-embolic strokes in comparison with other subtypes of ischaemic stroke

2009 ◽  
Vol 101 (05) ◽  
pp. 929-937 ◽  
Author(s):  
Domenico Di Raimondo ◽  
Salvatore Corrao ◽  
Riccardo Di Sciacca ◽  
Giuseppe Licata ◽  
Antonino Tuttolomondo ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Acute Ischaemic Stroke ◽  
Neurological Deficit ◽  
Plasma Levels ◽  
Infarct Volume ◽  
Blood Levels ◽  
Tnf Α ◽  
Inflammatory Activation ◽  
Median Plasma ◽  
The Relationship

SummaryFew studies have examined the relationship between inflammatory biomarker blood levels, cardioembolic stroke subtype and neurological deficit. So the aim of our study is to evaluate plasma levels of immuno-inflammatory variables in patients with cardio-embolic acute ischaemic stroke compared to other diagnostic subtypes and to evaluate the relationship between immuno-inflammatory variables, acute neurological deficit and brain infarct volume. One hundred twenty patients with acute ischaemic stroke and 123 controls without a diagnosis of acute ischaemic stroke were evaluated. The type of acute ischaemic stroke was classified according to the TOAST classification. We evaluated plasma levels of IL-1β, TNF-α, IL-6 and IL-10, E-selectin, P-selectin, sICAM-1,sVCAM-1, vWF, TPA and PAI-1. Patients with ischaemic stroke classified as cardio-embolic (CEI) showed, compared to other subtypes, significantly higher median plasma levels of TNF-α , IL-6 and IL-1β. Furthermore stroke patients classified as lacunar showed, compared to other subtypes, significantly lower median plasma levels of TNF-α, IL-6 and IL-1β. Multiple linear regression showed a significant association between the Scandinavian Stroke Scale (SSS) score at admission and diagnostic subtype, infarct volume of cardio-embolic strokes and some inflammatory variables. Our findings confirm that cardio-embolic strokes have a worse clinical presentation and produce larger and more disabling strokes than other ischaemic stroke subtypes reporting a possible explanation of higher immuno-inflammatory activation of the acute phase.

scholarly journals Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

2019 ◽  
Author(s):  
Xin-chun Ye ◽  
Qi Hao ◽  
Wei-jing Ma ◽  
Qiu-chen Zhao ◽  
Wei-wei Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Inos Expression ◽  
Microglial Cells ◽  
Brain Infarct ◽  
Tnf Α ◽  
Bv2 Microglial Cells ◽  
The Brain

Abstract Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer's disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. Adult male C57BL/6J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test and foot-fault test were evaluated on days 1, 3, 5 and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention. Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5 and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk and p-Syk expression was increased following the 3-h OGD and 0, 3 and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction. Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

scholarly journals TNF-α Pretreatment Improves the Survival and Function of Transplanted Human Neural Progenitor Cells Following Hypoxic-Ischemic Brain Injury

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1195
Author(s):  
Miri Kim ◽  
Kwangsoo Jung ◽  
Younhee Ko ◽  
Il-Sun Kim ◽  
Kyujin Hwang ◽  
...  
Keyword(s):  
Brain Injury ◽  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Infarct Volume ◽  
Fetal Brain ◽  
Neural Progenitor ◽  
Great Promise ◽  
Therapeutic Effects ◽  
Ischemic Brain ◽  
Tnf Α

Neural progenitor cells (NPCs) therapy offers great promise in hypoxic-ischemic (HI) brain injury. However, the poor survival of implanted NPCs in the HI host environment limits their therapeutic effects. Tumor necrosis factor-alpha (TNF-α) is a pleiotropic cytokine that is induced in response to a variety of pathological processes including inflammation and immunity. On the other hand, TNF-α has protective effects on cell apoptosis and death and affects the differentiation, proliferation, and survival of neural stem/progenitor cells in the brain. The present study investigated whether TNF-α pretreatment on human NPCs (hNPCs) enhances the effectiveness of cell transplantation therapy under ischemic brain. Fetal brain tissue-derived hNPCs were pretreated with TNF-α before being used in vitro experiments or transplantation. TNF-α significantly increased expression of cIAP2, and the use of short hairpin RNA-mediated knockdown of cIAP2 demonstrated that cIAP2 protected hNPCs against HI-induced cytotoxicity. In addition, pretreatment of hNPCs with TNF-α mediated neuroprotection by altering microglia polarization via increased expression of CX3CL1 and by enhancing expression of neurotrophic factors. Furthermore, transplantation of TNF-α-treated hNPCs reduced infarct volume and improved neurological functions in comparison with non-pretreated hNPCs or vehicle. These findings show that TNF-α pretreatment, which protects hNPCs from HI-injured brain-induced apoptosis and increases neuroprotection, is a simple and safe approach to improve the survival of transplanted hNPCs and the therapeutic efficacy of hNPCs in HI brain injury.

scholarly journals P1176The electrocardiographic and echocardiographic factors affecting infarct volume in acute ischaemic stroke

EP Europace ◽  
2018 ◽  
Vol 20 (suppl_1) ◽  
pp. i227-i227
Author(s):  
C T O'connor ◽  
D R Ranganathan ◽  
B Mcadam ◽  
D Williams ◽  
R Sheehan
Keyword(s):  
Ischaemic Stroke ◽  
Acute Ischaemic Stroke ◽  
Infarct Volume ◽  
Factors Affecting

scholarly journals [D-Ala2, D-Leu5] Enkephalin Inhibits TLR4/NF-κB Signaling Pathway and Protects Rat Brains against Focal Ischemia-Reperfusion Injury

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Danyun Fu ◽  
Haitong Liu ◽  
Jiang Zhu ◽  
Hongjiao Xu ◽  
Junyan Yao
Keyword(s):  
Cerebral Ischemia ◽  
Signaling Pathway ◽  
Western Blotting ◽  
Neurological Deficit ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Cerebral Infarct ◽  
Brain Inflammation ◽  
Tnf Α

Background. Cerebral ischemia-reperfusion (I/R) injury is the main cause of acute brain injury, which is a life-threatening disease due to the lack of effective treatments. [D-Ala2, D-Leu5] enkephalin (DADLE) is a synthetic delta-opioid receptor agonist that is reported to confer neuroprotective effect; however, the underlying mechanism is still being explored. The purpose of the present study is to determine whether DADLE administrated intracerebroventricularly could attenuate the cerebral I/R injury, to determine if this is through inhibiting the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway and therefore inhibiting neuroinflammation in an ischemic stroke model. Methods. Rats were subjected to 120 minutes of ischemia by transient middle cerebral artery occlusion (MCAO). At 45 minutes after ischemia, DADLE or control vehicle (artificial cerebrospinal fluid, ACSF) was given to the rats intracerebroventricularly. Neurological deficit, cerebral infarct volume, and histopathological changes were assessed at 24 hours after reperfusion. Brain inflammation was assessed by measuring tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the ischemic penumbra by ELISA. The expression of TLR4 was determined by immunohistochemistry staining and western blotting. The expression of NF-κB was investigated by western blotting. Results. Compared with the vehicle-treatment (ACSF), DADEL improved neurological deficit ( 9.6 ± 2.1 versus 13.8 ± 1.9 ), reduced cerebral infarct volume ( 18.74 ± 3.30 % versus 10.57 ± 2.50 % ), and increased the number of normal neurons ( 29.72 ± 8.53 % versus 51.37 ± 9.18 % ) after cerebral I/R injury in rats (all P < 0.05 ). Expressions of inflammatory molecules including TNF-α and IL-6 were highly expressed in the vehicle-treated rats, whereas treatment with DADLE downregulated these expressions ( P < 0.05 ). Additionally, cerebral I/R injury significantly increased the TLR4 and NF-κB expression in vehicle-control group, which was markedly inhibited by DADLE ( P < 0.05 ). Conclusions. DADLE, administrated intracerebroventricularly at 45 minutes after cerebral ischemia, significantly ameliorated I/R-induced brain damage in rats. This kind of neuroprotective effect appears to be related to the downregulation of TLR4-mediated inflammatory responses.

scholarly journals Blood levels of glutamate oxaloacetate transaminase are more strongly associated with good outcome in acute ischaemic stroke than glutamate pyruvate transaminase levels

2011 ◽  
Vol 121 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Francisco Campos ◽  
Manuel Rodríguez-Yáñez ◽  
Mar Castellanos ◽  
Susana Arias ◽  
María Pérez-Mato ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Acute Ischaemic Stroke ◽  
Infarct Volume ◽  
Blood Levels ◽  
Glutamate Oxaloacetate Transaminase ◽  
Glutamate Pyruvate Transaminase ◽  
Good Outcome ◽  
Poor Outcome ◽  
Pearson Coefficient ◽  
Glutamate Pyruvate

Ischaemic stroke is associated with an excessive release of glutamate in brain. GOT (glutamate-oxaloacetate transaminase) and GPT (glutamate-pyruvate transaminase) are two enzymes that are able to metabolize blood glutamate facilitating the lowering of extracellular levels of brain glutamate. Our aim was to study the association between blood levels of both enzymes and stroke outcome in patients with acute ischaemic stroke. We prospectively studied 365 patients with first ischaemic stroke<12 h. Glutamate, GOT and GPT levels were determined in blood samples obtained at admission. We considered functional outcome at 3 months [good outcome: mRS (modified Rankin Scale)≤2; poor outcome mRS >2], END (early neurological deterioration) in the first 72 h [increment ≥4 points in NIHSS (National Institutes of Health Stroke Scale)] and infarct volume [CT (computed tomography) at 36–72 h] as end points. We have found an inverse correlation between GOT and GPT levels and blood glutamate levels. Patients with poor outcome showed lower levels of GOT (11.9±8.2 compared with 22.7±10.2 m-units/ml, P<0.0001) and GPT (19.5±14.3 compared with 24.7±20.3 m-units/ml; P=0.004). A negative correlation has been found between GOT (Pearson coefficient=−0.477, P<0.0001) and GPT (Pearson coefficient=−0.116; P=0.027) levels and infarct volume. Patients with END showed higher levels of blood glutamate (381.7±97.9 compared with 237.6±114.0 μmol/l, P<0.0001) and lower levels of GOT (10.8±6.7 compared with 18.1±10.8 m-units/ml; P<0.0001). This clinical study shows an association between high blood GOT and GPT levels and good outcome in ischaemic stroke patients, this association being stronger for GOT than GPT levels.

scholarly journals Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Xin-Chun Ye ◽  
Qi Hao ◽  
Wei-Jing Ma ◽  
Qiu-Chen Zhao ◽  
Wei-Wei Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Inos Expression ◽  
Microglial Cells ◽  
Brain Infarct ◽  
Tnf Α ◽  
Bv2 Microglial Cells ◽  
The Brain

Abstract Background Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer’s disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. Methods Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention. Results Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction. Conclusion Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

scholarly journals Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

2019 ◽  
Author(s):  
Xin-chun Ye ◽  
Qi Hao ◽  
Wei-jing Ma ◽  
Qiu-chen Zhao ◽  
Wei-wei Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Inos Expression ◽  
Microglial Cells ◽  
Brain Infarct ◽  
Tnf Α ◽  
Bv2 Microglial Cells ◽  
The Brain

Abstract Background: Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer's disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. Methods: Adult male C57BL/6J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression was analyzed by western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol, PIC) were used for intervention. Results: Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, reduced the brain infarct volume and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data showed that Dectin-1, Syk, and p-Syk expression was increased following the 3-hour OGD followed by 0, 3, and 6 hours of reperfusion in BV2 microglial cells. LAM and PIC also reduced TNF-α and iNOS expression 3 hours after OGD/R induction. Conclusion: Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

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