scholarly journals Destructive Effects of Pyroptosis on Homeostasis of Neuron Survival Associated with the Dysfunctional BBB-Glymphatic System and Amyloid-Beta Accumulation after Cerebral Ischemia/Reperfusion in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhongkuan Lyu ◽  
Yuanjin Chan ◽  
Qiyue Li ◽  
Qiang Zhang ◽  
Kaili Liu ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Amyloid Beta ◽  
Neuronal Damage ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Specific Marker ◽  
Nissl Staining ◽  
Glymphatic System ◽  
Cerebral Ischemia Reperfusion

Neuroinflammation-related amyloid-beta peptide (Aβ) accumulation after cerebral ischemia/reperfusion (I/R) accounts for cerebral I/R injuries and poststroke dementia. Recently, pyroptosis, a proinflammatory cell death, has been identified as a crucial pathological link of cerebral I/R injuries. However, whether pyroptosis acts as a trigger of Aβ accumulation after cerebral I/R has not yet been demonstrated. Blood-brain barrier (BBB) and glymphatic system mediated by aquaporin-4 (AQP-4) on astrocytic endfeet are important pathways for the clearance of Aβ in the brain, and pyroptosis especially occurring in astrocytes after cerebral I/R potentially damages BBB integrity and glymphatic function and thus influences Aβ clearance and brain homeostasis. In present study, the method of middle cerebral artery occlusion/reperfusion (MCAO/R) was used for building models of focal cerebral I/R injuries in rats. Then, we used lipopolysaccharide and glycine as the agonist and inhibitor of pyroptosis, respectively, Western blotting for detections of pyroptosis, AQP-4, and Aβ1-42 oligomers, laser confocal microscopy for observations of pyroptosis and Aβ locations, and immunohistochemical stainings of SMI 71 (a specific marker for BBB integrity)/AQP-4 and Nissl staining for evaluating, respectively, BBB-glymphatic system and neuronal damage. The results showed that pyroptosis obviously promoted the loss of BBB integrity and AQP-4 polarization, brain edema, Aβ accumulation, and the formation of Aβ1-42 oligomers and thus increased neuronal damage after cerebral I/R. However, glycine could inhibit cerebral I/R-induced pyroptosis by alleviating cytomembrane damage and downregulating expression levels of cleaved caspase-11/1, N-terminal gasdermin D, NLRP3 (nucleotide-binding domain, leucine-rich repeat containing protein 3), interleukin-6 (IL-6) and IL-1β and markedly abate above pathological changes. Our study revealed that pyroptosis is a considerable factor causing toxic Aβ accumulation, dysfunctional BBB-glymphatic system, and neurological deficits after cerebral I/R, suggesting that targeting pyroptosis is a potential strategy for the prevention of ischemic stroke sequelae including dementia.

RTN1-C mediates cerebral ischemia/reperfusion injury via modulating autophagy

2020 ◽  
Author(s):  
Jun Ling ◽  
Haijian Cai ◽  
Muya Lin ◽  
Shunli Qi ◽  
Jian Du ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Cerebral Ischemia Reperfusion

Abstract It has been widely accepted that autophagic cell death exacerbates the progression of cerebral ischemia/reperfusion (I/R). Our previous study revealed that overexpression of reticulon protein 1-C (RTN1-C) is involved in cerebral I/R injury. However, the underlying mechanisms have not been studied intensively. This study was designed to evaluate the effect of RTN1-C on autophagy under cerebral I/R. Using an in vitro oxygen-glucose deprivation followed by reoxygenation and a transient middle cerebral artery occlusion model in rats, we found that the expression of RTN1-C protein was significantly upregulated. We also revealed that RTN1-C knockdown suppressed overactivated autophagy both in vivo and in vitro, as indicated by decreased expressions of autophagic proteins. The number of Beclin-1/propidium iodide-positive cells was significantly less in the LV-shRTN1-C group than in the LV-shNC group. In addition, rapamycin, an activator of autophagy, aggravated cerebral I/R injury. RTN1-C knockdown reduced brain infarct volume, improved neurological deficits, and attenuated cell vulnerability to cerebral I/R injury after rapamycin treatment. Taken together, our findings demonstrated that the modulation of autophagy from RTN1-C may play vital roles in cerebral I/R injury, providing a potential therapeutic treatment for ischemic brain injury.

scholarly journals A20-Binding Inhibitor of NF-κB 1 Ameliorates Neuroinflammation and Mediates Antineuroinflammatory Effect of Electroacupuncture in Cerebral Ischemia/Reperfusion Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xueling Zhou ◽  
Wenhao Lu ◽  
You Wang ◽  
Jiani Li ◽  
Yong Luo
Keyword(s):  
Cerebral Ischemia ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Cerebral Ischemia Reperfusion ◽  
Neuroprotective Strategy

A20-binding inhibitor of NF-κB 1 (ABIN1) is an inhibitor of NF-κB and exerts anti-inflammatory effect. Electroacupuncture (EA) is considered as a neuroprotective strategy by inhibiting neuroinflammatory damage after cerebral ischemia. This study was performed to explore the role of ABIN1 and investigate whether the ABIN1 is involved in the mechanism of EA in cerebral ischemia/reperfusion (I/R) rats. Male Sprague-Dawley (SD) rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and received EA after reperfusion once a day. Lentivirus-mediated ABIN1 gene knockdown was used to detect the role of ABIN1 in neuroinflammation after I/R. ABIN1 expression, proinflammatory cytokine levels, microglial activation, neurological function, infarct volumes, and NF-κB activation were assessed. ABIN1 expression was elevated in the peri-infarct cortex and was further upregulated by EA. ABIN1 knockdown increased the levels of proinflammatory cytokines and activation of microglia, worsened neurological deficits, and enlarged the infarct volume. Moreover, ABIN1 was blocked to partially reverse the neuroprotective effect of EA, and this treatment weakened the ability of EA to suppress NF-κB activity. Based on these findings, ABIN1 is a potential suppressor of neuroinflammation and ABIN1 mediates the antineuroinflammatory effect of EA in cerebral I/R rats.

scholarly journals Remote Limb Ischemic Postconditioning Ameliorated Microglia-Mediated Inflammation Against Cerebral Ischemia/Reperfusion through Modulating Microglial Activation and Polarization via TLR4 Pathway

2021 ◽  
Author(s):  
Dan Huang ◽  
Leyuan Zhang ◽  
Jiaju Zhong ◽  
Youli Zou ◽  
Guanghong Yuan ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Inflammatory Response ◽  
Infarct Size ◽  
Microglial Activation ◽  
Ischemia Reperfusion ◽  
Ischemic Postconditioning ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Nissl Staining ◽  
Cerebral Ischemia Reperfusion

Abstract Accumulating researches have indicated that remote limb ischemic postconditioning (RIPC) mediates neuroprotection by inhibition inflammatory response against cerebral ischemia/reperfusion (I/R), which is proved to correlated with microglial activation and polarization. However, the underlying mechanism remains unclear. In this study, middle cerebral artery occlusion /reperfusion model in Sprague-Dawley rats were conducted and treated with vehicle or RIPC immediately after reperfusion. Infarct size, and neurological scores were performed to asses stroke outcomes for 7 days. Brain damage and neuronal survival were detected using HE and Nissl staining. ELISA, western blotting and immunohistochemistry staining were utilized to evaluate inflammatory response, neuronal apoptosis, and microglial activation and polarization to M1- or M2-subtypes respectively. Results showed that RIPC significantly attenuated infarct size at 3d and alleviated the neurological deficits of rats at 3d and 7d post-ischemia. Furthermore, RIPC decreased expression of inflammatory cytokines IL-β, TNF-α and neuronal loss, and increased expression of cytokines IL-10 and Bcl-2. In addition, RIPC suppressed microglial activation and promoted microglial polarization to M2 type along with downregulation of TLR4 expression. These results suggested that RIPC was neuroprotective against ischemic stroke by modulating the activation of microglia/macrophages and encouraging polarization to M2 phenotype possibly through TLR4 signaling pathway.

scholarly journals Surface-modified engineered exosomes attenuated cerebral ischemia/reperfusion injury by targeting the delivery of quercetin towards impaired neurons

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lin Guo ◽  
Zhixuan Huang ◽  
Lijuan Huang ◽  
Jia Liang ◽  
Peng Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Targeted Delivery ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Therapeutic Drug ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

Abstract Background The incidence of ischemic stroke in the context of vascular disease is high, and the expression of growth-associated protein-43 (GAP43) increases when neurons are damaged or stimulated, especially in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). Experimental design We bioengineered neuron-targeting exosomes (Exo) conjugated to a monoclonal antibody against GAP43 (mAb GAP43) to promote the targeted delivery of quercetin (Que) to ischemic neurons with high GAP43 expression and investigated the ability of Exo to treat cerebral ischemia by scavenging reactive oxygen species (ROS). Results Our results suggested that Que loaded mAb GAP43 conjugated exosomes (Que/mAb GAP43-Exo) can specifically target damaged neurons through the interaction between Exo-delivered mAb GAP43 and GAP43 expressed in damaged neurons and improve survival of neurons by inhibiting ROS production through the activation of the Nrf2/HO-1 pathway. The brain infarct volume is smaller, and neurological recovery is more markedly improved following Que/mAb GAP43-Exo treatment than following free Que or Que-carrying exosome (Que-Exo) treatment in a rat induced by MCAO/R. Conclusions Que/mAb GAP43-Exo may serve a promising dual targeting and therapeutic drug delivery system for alleviating cerebral ischemia/reperfusion injury.

scholarly journals Tongxinluo Exerts Inhibitory Effects on Pyroptosis and Amyloid-β Peptide Accumulation after Cerebral Ischemia/Reperfusion in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bing Wang ◽  
Zhongkuan Lyu ◽  
Yuanjin Chan ◽  
Qiyue Li ◽  
Li Zhang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Protective Effects ◽  
Glymphatic System ◽  
Pyrin Domain ◽  
Cerebral Ischemia Reperfusion ◽  
Potential Possibility ◽  
Important Pathway

Amyloid-β peptide (Aβ) accumulation is a detrimental factor in cerebral ischemia/reperfusion (I/R) injuries accounting for dementia induced by ischemic stroke. In addition to blood brain barrier (BBB), the glymphatic system mediated by aquaporin-4 (AQP-4) on astrocytic endfeet functions as an important pathway for the clearance of Aβ in the brain. Cerebral I/R induced astrocytic pyroptosis potentially causes the AQP-4 polarization loss and dysfunctional BBB-glymphatic system exacerbating the accumulation of Aβ. Furthermore, Aβ toxicity has been identified as a trigger of pyroptosis and BBB damage, suggesting an amplified effect of Aβ accumulation after cerebral I/R. Therefore, based on our previous work, this study was designed to explore the intervention effects of Tongxinluo (TXL) on astrocytic pyroptosis and Aβ accumulation after cerebral I/R in rats. The results showed that TXL intervention obviously alleviated the degree of pyroptosis by downregulating expression levels of cleaved caspase-11/1, N-terminal gasdermin D, nucleotide-binding oligomerization domain-like receptors pyrin domain containing 3 (NLRP3), interleukin-6 (IL-6), and cleaved IL-1β and abated astrocytic pyroptosis after cerebral I/R. Moreover, TXL intervention facilitated to restore AQP-4 polarization and accordingly relieve Aβ accumulation around astrocytes in ischemic cortex and hippocampus as well as the formation of toxic Aβ (Aβ1–42 oligomer). Our study indicated that TXL intervention could exert protective effects on ischemic brain tissues against pyroptotic cell death, inhibit astrocytic pyroptosis, and reduce toxic Aβ accumulation around astrocytes in cerebral I/R injuries. Furthermore, our study provides biological evidence for the potential possibility of preventing and treating poststroke dementia with TXL in clinical practice.

scholarly journals Up-regulation of miR-499a-5p decreases cerebral ischemia/reperfusion injury by targeting PDCD4

2021 ◽  
Author(s):  
Weifeng Shan ◽  
Huifeng Ge ◽  
Bingquan Chen ◽  
Linger Huang ◽  
Shaojun Zhu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Tunel Staining ◽  
Cerebral Ischemia Reperfusion

Abstract MiR-499a-5p was significantly down-regulated in degenerative tissues and correlated with apoptosis. Nonetheless, the biological function of miR-499a-5p in acute ischemic stroke has been still unclear. In this study, we found the plasma levels of miR-499a-5p were significantly down-regulated in 64 ischemic stroke patients and negatively correlated with the National Institutes of Health Stroke Scale score. Then, we constructed cerebral ischemia/reperfusion (I/R) injury in rats after middle cerebral artery occlusion and subsequent reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R) treated SH-SY5Y cell model. Transfection with miR-499a-5p mimic was accomplished by intracerebroventricular injection in the in vivo I/R injury model. We further found miR-499a-5p overexpression decreased infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining. PDCD4 was a direct target of miR-499a-5p by luciferase report assay and western blotting. Knockdown of PDCD4 reduced the infarct damage and cortical neuron apoptosis caused by I/R injury. MiR-499a-5p exerted neuroprotective roles mainly through inhibiting PDCD4-mediated apoptosis by CCK-8 assay, LDH release assay and flow cytometry analysis. These findings suggest that miR-499a-5p might represent a novel target that regulates brain injury by inhibiting PDCD4-mediating apoptosis.

Nomilin protects against cerebral ischemia–reperfusion induced neurological deficits and blood–brain barrier disruption via the Nrf2 pathway

2019 ◽  
Vol 10 (9) ◽  
pp. 5323-5332 ◽  
Author(s):  
Yu-Sheng Shi ◽  
Yan Zhang ◽  
Bin Liu ◽  
Chun-Bin Li ◽  
Jiao Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Neurological Deficits ◽  
Nrf2 Pathway ◽  
Blood Brain Barrier Disruption ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury ◽  
Brain Barrier Disruption

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

scholarly journals Effects of Shaoyao-Gancao Decoction on Infarcted Cerebral Cortical Neurons: Suppression of the Inflammatory Response following Cerebral Ischemia-Reperfusion in a Rat Model

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ying Zhang ◽  
Xinling Jia ◽  
Jian Yang ◽  
Qing Li ◽  
Guofeng Yan ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Brain Tissue ◽  
Cortical Neurons ◽  
Ischemia Reperfusion ◽  
Serum Levels ◽  
Artery Occlusion ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Cortical Neurons ◽  
Staining Methods ◽  
Cerebral Artery Occlusion

The mechanisms by which Shaoyao-Gancao decoction (SGD) inhibits the production of inflammatory cytokines in serum and brain tissue after cerebral ischemia-reperfusion (CI-RP) in rats were investigated. A right middle cerebral artery occlusion was used to induce CI-RP after which the rats were divided into model (n=39), SGD (n=28), clopidogrel (n=25) and sham operated (n=34) groups. The Bederson scale was used to evaluate changes in behavioral indices. The levels of IL-1β, TNF-α, MCP-1, IL-10, RANTES, VEGF, and TGF-β1 in the serum and infarcted brain tissues were measured. Nissl body and immunohistochemical staining methods were used to detect biochemical changes in neurons, microglial cells, and astrocytes. Serum levels of VEGF, TNF-α, MCP-1, IL-1β, and IL-10 increased significantly 24 h after CI-RP. In brain tissue, levels of TNF-αand IL-1βsignificantly increased 24 h after CI-RP, whereas levels of TGF-β1 and MCP-1 were significantly higher 96 h after CI-RP (P<0.05). SGD or clopidogrel after CI-RP reduced TNF-αand IL-1βlevels in brain tissue and serum levels of MCP-1, IL-1β, and IL-10. SGD increased the number of NeuN-positive cells in infarcted brain tissue and reduced the number of IBA1-positive and GFAP-positive cells. The efficacy of SGD was significantly higher than that of clopidogrel.

Delayed treatment with magnesium: reduction of brain infarction and improvement of electrophysiological recovery following transient focal cerebral ischemia in rats

2005 ◽  
Vol 102 (6) ◽  
pp. 1085-1093 ◽  
Author(s):  
E-Jian Lee ◽  
Ming-Yang Lee ◽  
Guan-Liang Chang ◽  
Li-Hsuan Chen ◽  
Yu-Ling Hu ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Brain Infarction ◽  
Artery Occlusion ◽  
Sprague Dawley ◽  
Content Type ◽  
Delayed Treatment ◽  
Cerebral Ischemia Reperfusion ◽  
Fine Print

Object. The authors examined whether delayed treatment with Mg++ would reduce brain infarction and improve electrophysiological and neurobehavioral recovery following cerebral ischemia—reperfusion. Methods. Male Sprague—Dawley rats were subjected to right middle cerebral artery occlusion for 90 minutes followed by 72 hours of reperfusion. Magnesium sulfate (750 µmol/kg) or vehicle was given via intracarotid infusion at the beginning of reperfusion. Neurobehavioral outcome and somatosensory evoked potentials (SSEPs) were examined before and 72 hours after ischemia—reperfusion. Brain infarction was assessed after the rats had died. Before ischemia—reperfusion, stable SSEP waveforms were recorded after individual fore- and hindpaw stimulations. At 72 hours of perfusion the SSEPs recorded from ischemic fore- and hindpaw cortical fields were depressed in vehicle-injected animals and the amplitudes decreased to 19 and 27% of baseline, respectively (p < 0.001). Relative to controls, the amplitudes of SSEPs recorded from both ischemic fore- and hindpaw cortical field in the Mg++-treated animals were significantly improved by 23% (p < 0.005) and 39% (p < 0.001) of baselines, respectively. In addition, Mg++ improved sensory and motor neurobehavioral outcomes by 34% (p < 0.01) and 24% (p < 0.05), respectively, and reduced cortical (p < 0.05) and striatal (p < 0.05) infarct sizes by 42 and 36%, respectively. Conclusions. Administration of Mg++ at the commencement of reperfusion enhances electrophysiological and neurobehavioral recovery and reduces brain infarction after cerebral ischemia—reperfusion. Because Mg++ has already been used clinically, it may be worthwhile to investigate it further to see if it holds potential benefits for patients with ischemic stroke and for those who will undergo carotid endarterectomy.

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