scholarly journals Isorhynchophylline Ameliorates Cerebral Ischemia/Reperfusion Injury by Inhibiting CX3CR1-Mediated Microglial Activation and Neuroinflammation

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Deng ◽  
Ruirong Tan ◽  
Fei Li ◽  
Yuangui Liu ◽  
Jingshan Shi ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Microglial Activation ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Underlying Mechanism ◽  
Reperfusion Therapy ◽  
Artery Occlusion ◽  
Cerebral Ischemic

Reperfusion therapy is an effective way to rescue cerebral ischemic injury, but this therapy also shows the detrimental risk of devastating disorders and death due to the possible inflammatory responses involved in the pathologies. Hence, the therapy of ischemia/reperfusion (I/R) injury is a great challenge currently. Isorhynchophylline (IRN), a tetracyclic oxindole alkaloid extracted from Uncaria rhynchophylla, has previously shown neuroprotective and anti-inflammatory effects in microglial cells. This study systematically investigates the effect of IRN on I/R injury and its underlying mechanism. The effects of IRN on neuronal injury and microglia-mediated inflammatory response were assessed on a rat model with middle cerebral artery occlusion (MCAO) and reperfusion-induced injury. We found that IRN treatment attenuated the infarct volume and improved the neurological function in I/R injury rats. IRN treatment also reduced the neuronal death rate, brain water content, and aquaporin-4 expression in the ischemic penumbra of I/R injury rats’ brains. Besides, IRN treatment could inhibit the following process, including IκB-α degradation, NF-κB p65 activation, and CX3CR1 expression, as well as the microglial activation and inflammatory response. These findings suggest that IRN is a promising candidate to treat the cerebral I/R injury via inhibiting microglia activation and neuroinflammation.

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.

MitoKATP opener, diazoxide, reduces neuronal damage after middle cerebral artery occlusion in the rat

2002 ◽  
Vol 283 (3) ◽  
pp. H1005-H1011 ◽  
Author(s):  
Katsuyoshi Shimizu ◽  
Zsombor Lacza ◽  
Nishadi Rajapakse ◽  
Takashi Horiguchi ◽  
James Snipes ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Ischemia Reperfusion Injury ◽  
Neuronal Damage ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Sham Treatment ◽  
Cerebral Artery Occlusion

We investigated effects of diazoxide, a selective opener of mitochondrial ATP-sensitive K+ (mitoKATP) channels, against brain damage after middle cerebral artery occlusion (MCAO) in male Wistar rats. Diazoxide (0.4 or 2 mM in 30 μl saline) or saline (sham) was infused into the right lateral ventricle 15 min before MCAO. Neurological score was improved 24 h later in the animals treated with 2 mM diazoxide (13.8 ± 0.7, n = 13) compared with sham treatment (9.5 ± 0.2, n = 6, P < 0.01). The total percent infarct volume (MCAO vs. contralateral side) of sham treatment animals was 43.6 ± 3.6% ( n = 12). Treatment with 2 mM diazoxide reduced the infarct volume to 20.9 ± 4.8% ( n = 13, P < 0.05). Effects of diazoxide were prominent in the cerebral cortex. The protective effect of diazoxide was completely prevented by the pretreatment with 5-hydroxydecanoate (100 mM in 10 μl saline), a selective blocker of mitoKATP channels ( n = 6). These results indicate that selective opening of the mitoKATP channel has neuroprotective effects against ischemia-reperfusion injury in the rat brain.

scholarly journals miR-19a/b-3p promotes inflammation during cerebral ischemia/reperfusion injury via SIRT1/FoxO3/SPHK1 pathway

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Feng Zhou ◽  
Yu-Kai Wang ◽  
Cheng-Guo Zhang ◽  
Bing-Yi Wu
Keyword(s):  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Luciferase Assay ◽  
In Vivo Model ◽  
Tunel Staining

Abstract Background Stroke affects 3–4% of adults and kills numerous people each year. Recovering blood flow with minimal reperfusion-induced injury is crucial. However, the mechanisms underlying reperfusion-induced injury, particularly inflammation, are not well understood. Here, we investigated the function of miR-19a/b-3p/SIRT1/FoxO3/SPHK1 axis in ischemia/reperfusion (I/R). Methods MCAO (middle cerebral artery occlusion) reperfusion rat model was used as the in vivo model of I/R. Cultured neuronal cells subjected to OGD/R (oxygen glucose deprivation/reperfusion) were used as the in vitro model of I/R. MTT assay was used to assess cell viability and TUNEL staining was used to measure cell apoptosis. H&E staining was employed to examine cell morphology. qRT-PCR and western blot were performed to determine levels of miR-19a/b-3p, SIRT1, FoxO3, SPHK1, NF-κB p65, and cytokines like TNF-α, IL-6, and IL-1β. EMSA and ChIP were performed to validate the interaction of FoxO3 with SPHK1 promoter. Dual luciferase assay and RIP were used to verify the binding of miR-19a/b-3p with SIRT1 mRNA. Results miR-19a/b-3p, FoxO3, SPHK1, NF-κB p65, and cytokines were elevated while SIRT1 was reduced in brain tissues following MCAO/reperfusion or in cells upon OGD/R. Knockdown of SPHK1 or FoxO3 suppressed I/R-induced inflammation and cell death. Furthermore, knockdown of FoxO3 reversed the effects of SIRT1 knockdown. Inhibition of the miR-19a/b-3p suppressed inflammation and this suppression was blocked by SIRT1 knockdown. FoxO3 bound SPHK1 promoter and activated its transcription. miR-19a/b-3p directly targeted SIRT1 mRNA. Conclusion miR-19a/b-3p promotes inflammatory responses during I/R via targeting SIRT1/FoxO3/SPHK1 axis.

scholarly journals Reperfusion Injury: Demonstration of Brain Damage Produced by Reperfusion after Transient Focal Ischemia in Rats

1997 ◽  
Vol 17 (10) ◽  
pp. 1048-1056 ◽  
Author(s):  
Jaroslaw Aronowski ◽  
Roger Strong ◽  
James C. Grotta
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Reperfusion Therapy ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Spontaneously Hypertensive ◽  
Beneficial Effects ◽  
Transient Focal Ischemia

During reperfusion after ischemia, deleterious biochemical processes can be triggered that may antagonize the beneficial effects of reperfusion. Research into the understanding and treatment of reperfusion injury (RI) is an important objective in the new era of reperfusion therapy for stroke. To investigate RI, permanent and reversible unilateral middle cerebral artery/common carotid artery (MCA/CCA) occlusion (monitored by laser Doppler) of variable duration in Long-Evans (LE) and spontaneously hypertensive (SH) rats and unilateral MCA and bilateral CCA occlusion in selected LE rats was induced. In LE rats, infarct volume after 24 hours of permanent unilateral MCA/CCA occlusion was 31.1 ± 34.6 mm3 and was only 28% of the infarct volume after 120 to 300 minutes of reversible occlusion plus 24 hours of reperfusion, indicating that 72% of the damage of ischemia/reperfusion is produced by RI. When reversible ischemia was prolonged to 480 and 1080 minutes, infarct volume was 39.6 mm3 and 16.6 mm3, respectively, being indistinguishable from the damage produced by permanent ischemia and significantly smaller than damage after 120 to 300 minutes of ischemia. Reperfusion injury was not seen in SH rats or with bilateral CCA occlusion in LE rats, in which perfusion is reduced more profoundly. Reperfusion injury was ameliorated by the protein synthesis inhibitor cycloheximide or spin-trap agent N-tert-butyl-alpha-phenylnitrone pretreatment.

scholarly journals Exogenous hydrogen sulfide attenuates cerebral ischemia–reperfusion injury by inhibiting autophagy in mice

2016 ◽  
Vol 94 (11) ◽  
pp. 1187-1192 ◽  
Author(s):  
Mengyang Shui ◽  
Xiaoyan Liu ◽  
Yuanjun Zhu ◽  
Yinye Wang
Keyword(s):  
Hydrogen Sulfide ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Ischemic Injury ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Western Blot Assay

Hydrogen sulfide (H2S), the third gas transmitter, has been proven to be neuroprotective in cerebral ischemic injury, but whether its effect is mediated by regulating autophagy is not yet clear. The present study was undertaken to explore the underlying mechanisms of exogenous H2S on autophagy regulation in cerebral ischemia. The effects and its connection with autophagy of NaHS, a H2S donor, were observed through neurological deficits and cerebral infarct volume in middle cerebral artery occlusion (MCAO) mice; autophagy-related proteins and autophagy complex levels in the ischemic hemisphere were detected with Western blot assay. Compared with the model group, NaHS significantly decreased infarct volume and improved neurological deficits; rapamycin, an autophagy activator, abolished the effect of NaHS; NaHS decreased the expression of LC3-II and up-regulated p62 expression in the ischemic cortex 24 h after ischemia. However, NaHS did not significantly influence Beclin-1 expression. H2S has a neuroprotective effect on ischemic injury in MCAO mice; this effect is associated with its influence in down-regulating autophagosome accumulation.

scholarly journals Deficiency of PAR4 Attenuates Cerebral Ischemia/Reperfusion Injury in Mice

2010 ◽  
Vol 30 (5) ◽  
pp. 1044-1052 ◽  
Author(s):  
Yingying Mao ◽  
Ming Zhang ◽  
Ronald F Tuma ◽  
Satya P Kunapuli
Keyword(s):  
Cerebral Ischemia ◽  
Platelet Activation ◽  
Cerebral Edema ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Wild Type ◽  
Cerebral Ischemia Reperfusion ◽  
The Usa

Stroke is the third leading cause of death in the USA. Antithrombotic therapy targeting platelet activation is one of the treatments for ischemic stroke. Here we investigate the role of one of the thrombin receptors, protease-activated receptor 4 (PAR4), in a mouse transient middle cerebral artery occlusion (MCAO) model. After a 60 min MCAO and 23 h reperfusion, leukocyte and platelet rolling and adhesion on cerebral venules, blood–brain barrier (BBB) permeability, and cerebral edema were compared in PAR4-deficient mice and wild-type mice. Cerebral infarction volume and neuronal death were also measured. PAR4−/− mice had more than an 80% reduction of infarct volume and significantly improved neurologic and motor function compared with wild-type mice after MCAO. Furthermore, deficiency of PAR4 significantly inhibits the rolling and adhesion of both platelets and leukocytes after MCAO. BBB disruption and cerebral edema were also attenuated in PAR4−/− mice compared with wild-type animals. The results of this investigation indicate that deficiency of PAR4 protects mice from cerebral ischemia/reperfusion (I/R) injury, partially through inhibition of platelet activation and attenuation of microvascular inflammation.

scholarly journals Inflammatory Resolution and Vascular Barrier Restoration after Retinal Ischemia Reperfusion Injury

2021 ◽  
Author(s):  
Steven F Abcouwer ◽  
Sumathi Shanmugam ◽  
Arivalagan Muthusamy ◽  
Cheng-mao Lin ◽  
Dejuan Kong ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Protein Content ◽  
Vascular Permeability ◽  
Microglial Activation ◽  
Time Course ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Retinal Ischemia ◽  
Resolution Of Inflammation ◽  
Inflammatory Monocytes

Abstract Several retinal pathologies exhibit both inflammation and breakdown of the inner blood-retinal barrier (iBRB) resulting in vascular permeability, suggesting that treatments that trigger resolution of inflammation may also promote iBRB restoration. Using the mouse retinal ischemia-reperfusion (IR) injury model we followed the time course of neurodegeneration, inflammation and iBRB disruption and repair to examine the relationship between resolution of inflammation and iBRB restoration and to determine if minocycline, a tetracycline derivative shown to reverse microglial activation, can hasten these processes. A 90 min ischemic insult followed by reperfusion in the retina induced cell apoptosis and inner retina thinning that progressed for approximately 2 weeks. IR increased vascular permeability within hours, which lasted for at least 2 weeks and resolved between 3 and 4 weeks after injury. Increased vascular permeability coincided with alteration and loss of endothelial cell tight junction (TJ) protein content and disorganization of TJ protein complexes. Whereas repletion of TJ protein content occurred within days, restoration of the iBRB coincided with eventual re-organization of TJ complexes at the cell border. A robust inflammatory response was evident a 1 day after IR and progressed to resolution over the 4-week time course. The inflammatory response included a rapid and transient infiltration of granulocytes and Ly6C + classical inflammatory monocytes, a slow accumulation of Ly6C neg monocyte/macrophages, and activation, proliferation and mobilization of resident microglia. The presence of monocyte/macrophages and increased numbers of microglia were sustained until the iBRB was eventually restored. Intervention with minocycline to reverse microglial activation promoted early restoration of the iBRB. These results suggest that resolution of inflammation and restoration of the iBRB following retinal IR injury are functionally linked.

scholarly journals Inflammatory resolution and vascular barrier restoration after retinal ischemia reperfusion injury

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Steven F. Abcouwer ◽  
Sumathi Shanmugam ◽  
Arivalagan Muthusamy ◽  
Cheng-mao Lin ◽  
Dejuan Kong ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Vascular Permeability ◽  
Microglial Activation ◽  
Time Course ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Retinal Ischemia ◽  
Blood Retinal Barrier ◽  
Resolution Of Inflammation ◽  
Inflammatory Monocytes

Abstract Background Several retinal pathologies exhibit both inflammation and breakdown of the inner blood-retinal barrier (iBRB) resulting in vascular permeability, suggesting that treatments that trigger resolution of inflammation may also promote iBRB restoration. Methods Using the mouse retinal ischemia-reperfusion (IR) injury model, we followed the time course of neurodegeneration, inflammation, and iBRB disruption and repair to examine the relationship between resolution of inflammation and iBRB restoration and to determine if minocycline, a tetracycline derivative shown to reverse microglial activation, can hasten these processes. Results A 90-min ischemic insult followed by reperfusion in the retina induced cell apoptosis and inner retina thinning that progressed for approximately 2 weeks. IR increased vascular permeability within hours, which resolved between 3 and 4 weeks after injury. Increased vascular permeability coincided with alteration and loss of endothelial cell tight junction (TJ) protein content and disorganization of TJ protein complexes. Shunting of blood flow away from leaky vessels and dropout of leaky capillaries were eliminated as possible mechanisms for restoring the iBRB. Repletion of TJ protein contents occurred within 2 days after injury, long before restoration of the iBRB. In contrast, the eventual re-organization of TJ complexes at the cell border coincided with restoration of the barrier. A robust inflammatory response was evident a 1 day after IR and progressed to resolution over the 4-week time course. The inflammatory response included a rapid and transient infiltration of granulocytes and Ly6C+ classical inflammatory monocytes, a slow accumulation of Ly6Cneg monocyte/macrophages, and activation, proliferation, and mobilization of resident microglia. Extravasation of the majority of CD45+ leukocytes occurred from the superficial plexus. The presence of monocyte/macrophages and increased numbers of microglia were sustained until the iBRB was eventually restored. Intervention with minocycline to reverse microglial activation at 1 week after injury promoted early restoration of the iBRB coinciding with decreased expression of mRNAs for the microglial M1 markers TNF-α, IL-1β, and Ptgs2 (Cox-2) and increased expression of secreted serine protease inhibitor Serpina3n mRNA. Conclusions These results suggest that iBRB restoration occurs as TJ complexes are reorganized and that resolution of inflammation and restoration of the iBRB following retinal IR injury are functionally linked.

scholarly journals Stargazin Interaction With Serine Racemase Mediates Cerebral Ischemia/Reperfusion Injury in Rats

2021 ◽  
Author(s):  
Xiaqing Yuan ◽  
Shanshan Diao ◽  
Shujun Chen ◽  
Jiajie Lu ◽  
Haitao Shen ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Serine Racemase ◽  
Dependent Protein ◽  
Cerebral Ischemia Reperfusion Injury ◽  
Cerebral Ischemic ◽  
Cerebral Ischemic Damage ◽  
Cerebral Artery Occlusion

Abstract D-Serine is thought to be involved in N-methyl-D-aspartate (NMDA)-type glutamate receptor-mediated neurotoxicity and plays a pathophysiologic role in stroke. D-Serine is synthesized by serine racemase (SR), which directly converts L-serine into D-serine. The deletion of SR has been reported to protect against cerebral ischemia damage. Additionally, SR catalytic activity is physiologically regulated by its binding to stargazin. However, whether the stargazin-SR interaction affects the level of stroke damage remains elusive. We showed that cerebral ischemia increased the interaction of stargazin and SR and decreased the levels of D-serine. Disrupting the stargazin-SR interaction by knocking down stargazin aggravated cerebral ischemic insults. We found that cerebral ischemia decreased the phosphorylation of stargazin at the Thr-321 residue, which was phosphorylated by cAMP-dependent protein kinase A (PKA). Treatment with the PKA inhibitor H89 blocked stargazin T321 phosphorylation, augmented the stargazin-SR interaction, decreased D-serine levels, and alleviated focal cerebral ischemic damage in rats subjected to middle cerebral artery occlusion and reperfusion (MCAO/R). Thus, the stargazin-SR interaction is a promising strategy in the treatment of stroke.

scholarly journals Xingnaojing Injection Protects against Cerebral Ischemia Reperfusion Injury via PI3K/Akt-Mediated eNOS Phosphorylation

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yue-Ming Zhang ◽  
Xiao-Yu Qu ◽  
Jing-Hui Zhai ◽  
Li-Na Tao ◽  
Huan Gao ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Underlying Mechanism ◽  
Dapi Staining ◽  
Pi3k Inhibitor Ly294002 ◽  
Cerebral Ischemic

Xingnaojing (XNJ) injection, derived from traditional Chinese medicine formulation, has a protective effect against stroke, but the underlying mechanism is unclear, which severely limited its clinical application. This research aims to elucidate the role and mechanism of XNJ in reducing cerebral ischemic reperfusion (I/R) injury. Rats received 2 h cerebral ischemia followed by reperfusion of 24 h and were intraperitoneally given 5, 10, or 15 ml/kg XNJ 24 h before ischemia and at the onset of reperfusion, respectively. TTC staining, HE staining, and neurological score were implied to evaluate the effectiveness of XNJ. The protein expressions of PI3K/Akt and eNOS signaling were measured. Experiments were further performed in human brain microvascular endothelial cells (HBMECs) to investigate the protective mechanisms of XNJ. HBMECs were subjected to 3 h oxygen and glucose deprivation following 24 h of reoxygenation (OGD) to mimic cerebral I/R in vitro. PI3K inhibitor LY294002 was added with or without the preconditioning of XNJ. Multiple methods including western blot, immunofluorescence, DAPI staining, JC-1, and flow cytometry were carried out to evaluate the effect of XNJ on HBMECs. XNJ could improve rat cerebral ischemic injury and OGD induced HBMECs apoptosis. In vivo and in vitro researches indicated that the mechanism might be relevant to the activation of PI3K/Akt/eNOS signaling.

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