scholarly journals Deficiency of ROS-Activated TRPM2 Channel Protects Neurons from Cerebral Ischemia-Reperfusion Injury through Upregulating Autophagy

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xupang Hu ◽  
Lijuan Wu ◽  
Xingyu Liu ◽  
Yi Zhang ◽  
Min Xu ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Neuronal Damage ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Mtor Pathway ◽  
Regulation Mechanism ◽  
Cerebral Ischemia Reperfusion ◽  
Trpm2 Channel ◽  
Autophagy Activity

Cerebral ischemia-reperfusion (I-R) transiently increased autophagy by producing excessively reactive oxygen species (ROS); on the other hand, activated autophagy would remove ROS-damaged mitochondria and proteins, which led to cell survival. However, the regulation mechanism of autophagy activity during cerebral I-R is still unclear. In this study, we found that deficiency of the TRPM2 channel which is a ROS sensor significantly decreased I-R-induced neuronal damage. I-R transiently increased autophagy activity both in vitro and in vivo. More importantly, TRPM2 deficiency decreased I-R-induced neurological deficit score and infarct volume. Interestingly, our results indicated that TRPM2 deficiency could further activate AMPK rather than Beclin1 activity, suggesting that TRPM2 inhibits autophagy by regulating the AMPK/mTOR pathway in I-R. In conclusion, our study reveals that ROS-activated TRPM2 inhibits autophagy by downregulating the AMPK/mTOR pathway, which results in neuronal death induced by cerebral I-R, further supporting that TRPM2 might be a potential drug target for cerebral ischemic injury therapy.

scholarly journals Inhibition of autophagy by CRMP2-derived peptide ST2-104 (R9-CBD3) via a CaMKKβ/AMPK/mTOR pathway contributes to ischemic postconditioning-induced neuroprotection against cerebral ischemia-reperfusion injury

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yuan Yao ◽  
Yingshi Ji ◽  
Jinghong Ren ◽  
Huanyu Liu ◽  
Rajesh Khanna ◽  
...  
Keyword(s):  
Cell Death ◽  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Neuronal Damage ◽  
Ischemia Reperfusion ◽  
Mtor Pathway ◽  
Cerebral Ischemia Reperfusion ◽  
Model Of Alzheimer’S Disease ◽  
Cerebral Ischemia Reperfusion Injury

AbstractCerebral ischemia, a common cerebrovascular disease, is characterized by functional deficits and apoptotic cell death. Autophagy, a type of programmed cell death, plays critical roles in controlling neuronal damage and metabolic homeostasis, and has been inextricably linked to cerebral ischemia. We previously identified a short peptide aptamer from collapsin response mediator protein 2 (CRMP2), designated the Ca2+ channel-binding domain 3 (CBD3) peptide, that conferred protection against excitotoxicity and traumatic brain injury. ST2-104, a nona-arginine (R9)-fused CBD3 peptide, exerted beneficial effects on neuropathic pain and was neuroprotective in a model of Alzheimer’s disease; however, the effect of ST2-104 on cerebral ischemia and its mechanism of action have not been studied. In this study, we modeled cerebral ischemia–reperfusion injury in rats with the middle cerebral artery occlusion (MCAO) as well as challenged SH-SY5Y neuroblastoma cells with glutamate to induce toxicity to interrogate the effects of ST2-104 on autophagy following ischemic/excitotoxic insults. ST2-104 reduced the infarct volume and improved the neurological score of rats subjected to MCAO. ST2-104 protected SH-SY5Y cells from death following glutamate exposure via blunting apoptosis and autophagy as well as limiting excessive calcium entry. 3-Methyladenine (3-MA), an inhibitor of autophagy, promoted the effects of ST2-104 in inhibiting apoptosis triggered by glutamate while rapamycin, an activator of autophagy, failed to do so. ST2-104 peptide reversed glutamate-induced apoptosis via inhibiting Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ)-mediated autophagy, which was partly enhanced by STO-609 (an inhibitor of CaMKKβ). ST2-104 attenuated neuronal apoptosis by inhibiting autophagy through CaMKKβ/AMPK/mTOR pathway. Our results suggest that the neuroprotective effect of ST2-104 are due to actions on the crosstalk between apoptosis and autophagy via the CaMKKβ/AMPK/mTOR signaling pathway. The findings present novel insights into the potential neuroprotection of ST2-104 in cerebral ischemia.

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 Protective effect of extract of the Camellia japonica L. on cerebral ischemia-reperfusion injury in rats

2019 ◽  
Vol 77 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Weizhuo Lu ◽  
Ling Xv ◽  
Jiyue Wen
Keyword(s):  
Cerebral Ischemia ◽  
Protective Effect ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Camellia Japonica ◽  
Lactate Dehydrogenase Activity ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

ABSTRACT Objective: We investigated the protective effect of the extract of the Camellia japonica L. flower on cerebral ischemia-reperfusion injury in rats. Methods: The rat ischemia-reperfusion injury was induced by middle cerebral artery occlusion for 90 minutes and reperfusion for 48 hours. The animals received an intravenous injection once a day of 20, 40, 80 mg/kg extract of C. japonica for three consecutive days before the ischemia reperfusion. The learning and memory function, the infarct volume, serum malondialdehyde (MDA) level and lactate dehydrogenase activity, and extravasation of immunoglobulin G (IgG) into cerebral parenchyma were assessed as the cell damage index. Results: Pretreatment with extract of C. japonica markedly reduced the infarct volume, serum malondialdehyde level and lactate dehydrogenase activity, and markedly inhibited the extravasation of IgG. Moreover, pretreatment with extract of C. japonica may also inhibit the learning and memory deficits induced by an ischemia-reperfusion injury. Conclusion: It was concluded that pretreatment with extract of C. japonica has a protective effect on cerebral ischemia-reperfusion injury in rats.

scholarly journals N6-methyladenosine demethylases Alkbh5/Fto regulate cerebral ischemia-reperfusion injury

2020 ◽  
Vol 11 ◽  
pp. 204062232091602 ◽  
Author(s):  
Kaiwei Xu ◽  
Yunchang Mo ◽  
Dan Li ◽  
Qimin Yu ◽  
Lu Wang ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Neuronal Damage ◽  
Ischemia Reperfusion ◽  
Neuronal Cell ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

Background: Although N6-methyladenosine (m6A) plays a very important role in different biological processes, its function in the brain has not been fully explored. Thus, we investigated the roles of the RNA demethylases Alkbh5/Fto in cerebral ischemia-reperfusion injury. Methods: We used a rat model and primary neuronal cell culture to study the role of m6A and Alkbh5/Fto in the cerebral cortex ischemic penumbra after cerebral ischemia-reperfusion injury. We used Alkbh5-shRNA and Lv-Fto ( in vitro) to regulate the expression of Alkbh5/Fto to study their regulation of m6A in the cerebral cortex and to study brain function after ischemia-reperfusion injury. Results: We found that RNA m6A levels increased consecutive to the increase of Alkbh5 expression in both the cerebral cortex of rats after middle cerebral artery occlusion, and in primary neurons after oxygen deprivation/reoxygenation. In contrast, Fto expression decreased after these perturbations. Our results suggest that knocking down Alkbh5 can aggravate neuronal damage. This is due to the demethylation of Alkbh5 and Fto, which selectively demethylate the Bcl2 transcript, preventing Bcl2 transcript degradation and enhancing Bcl2 protein expression. Conclusion: Collectively, our results demonstrate that the demethylases Alkbh5/Fto co-regulate m6A demethylation, which plays a crucial role in cerebral ischemia-reperfusion injury. The results provide novel insights into potential therapeutic mechanisms for stroke.

Neuroprotective Effect of Urinary Trypsin Inhibitor against Focal Cerebral Ischemia–Reperfusion Injury in Rats

2003 ◽  
Vol 98 (2) ◽  
pp. 465-473 ◽  
Author(s):  
Toshiyuki Yano ◽  
Sakiko Anraku ◽  
Ryosuke Nakayama ◽  
Kazuo Ushijima
Keyword(s):  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Trypsin Inhibitor ◽  
Ischemia Reperfusion Injury ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Saline Control ◽  
Urinary Trypsin Inhibitor ◽  
Cerebral Ischemia Reperfusion

Background Acute inflammatory reactions cause neuronal damage in cerebral ischemia-reperfusion. Urinary trypsin inhibitor (UTI), a serine protease inhibitor, is cytoprotective against ischemia-reperfusion injury in the liver, intestine, kidney, heart, and lung through its antiinflammatory activity. Neuroprotective action of UTI on transient global cerebral ischemia has been documented. This is the first study to determine whether UTI is neuroprotective against transient focal cerebral ischemia. Methods Adult male Wistar rats were randomly assigned to the following treatment groups: 0.9% saline (control, n = 9); 100,000 U/kg UTI (n = 9); and 300,000 U/kg UTI (n = 9). Treatments were performed intravenously 10 min before right middle cerebral artery occlusion for 2 h and subsequent reperfusion. Ninety-six hours after the onset of reperfusion, the motor neurologic deficit and the cerebral infarct size were evaluated. Furthermore, immunohistochemical staining for myeloperoxidase and nitrotyrosine to count infiltrating neutrophils and nitrated cells, respectively, was performed on the brain sections. Results Infarct volume in the 300,000 U/kg UTI group was smaller than in the 100,000 U/kg UTI and saline control groups (P < 0.05). Treatment with 300,000 U/kg UTI showed a trend to improve neurologic outcome but did not reach statistical significance (P = 0.0693). The significant decrease in neutrophil infiltration was observed in the ischemic hemisphere treated with 300,000 U/kg UTI compared with saline control (P < 0.05). Nitrotyrosine deposition in the ischemic hemisphere was significantly reduced in the 300,000 U/kg UTI group compared with saline control and 100,000 U/kg UTI groups (P < 0.05). Conclusions Intravenous pretreatment with 300,000 U/kg UTI reduces focal ischemia-reperfusion injury in the rat brain, potentially opening a novel therapeutic avenue for the treatment of cerebral ischemia.

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 Acupuncture protects against cerebral ischemia-reperfusion injury via suppressing endoplasmic reticulum stress-mediated autophagy and apoptosis

2020 ◽  
Author(s):  
Xiaowei Sun ◽  
Hao Liu ◽  
Zhongren Sun ◽  
Beng Zhang ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cerebral Ischemia ◽  
Er Stress ◽  
Acupuncture Treatment ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion ◽  
Neurological Score

Abstract Background: Acupuncture treatment possesses the neuroprotection potential to attenuate cerebral ischemia-reperfusion (I/R) injury. Endoplasmic reticulum (ER) stress has been suggested to be involved in the pathogenic mechanism of cerebral I/R injury. Whether acupuncture protects against cerebral I/R injury via regulating ER stress remains unclear. This study aimed to evaluate the role of ER stress in the neuroprotection of acupuncture against cerebral I/R injury and its underlying mechanisms. Methods: Cerebral I/R injury was induced by middle cerebral artery occlusion (MCAO) in rats. Acupuncture was carried out at Baihui (GV 20), Hegu (L14), and Taichong (Liv3) acupoints in rats immediately after reperfusion. The infarct volumes, neurological score, ER stress, autophagy and apoptosis were determined. Results: Acupuncture treatment decreased infarct volume, neurological score and suppressed ER stress via inactivation of ATF-6, PERK, and IRE1 pathways in MCAO rats. Attributing to ER stress suppression, 4-PBA (ER stress inhibitor) promoted the beneficial effect of acupuncture against cerebral I/R injury. Whereas, ER stress activator tunicamycin significantly counteracted the neuroprotective effects of acupuncture. In addition, acupuncture restrained autophagy via regulating ER stress in MCAO rats. Finally, ER stress took part in the neuroprotective effect of acupuncture against apoptosis in cerebral I/R injury. Conclusions: Our findings suggest that acupuncture offers neuroprotection against cerebral I/R injury, which is attributed to repressing ER stress-mediated autophagy and apoptosis.

scholarly journals Normobaric Oxygen (NBO) Therapy Reduces Cerebral Ischemia/Reperfusion Injury through Inhibition of Early Autophagy

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Meng Wang ◽  
Xiaokun Geng ◽  
Chaitu Dandu ◽  
Radhika Patel ◽  
Yuchuan Ding
Keyword(s):  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Ischemic Injury ◽  
Normobaric Oxygen ◽  
Sequestosome 1 ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

Objectives. Normobaric oxygen (NBO) therapy has great clinical potential in the treatment of ischemic stroke, but its underlying mechanism is unknown. Our study aimed to investigate the role of autophagy during the application of NBO on cerebral ischemia/reperfusion injury. Methods. Male Sprague Dawley rats received 2 hours of middle cerebral artery occlusion (MCAO), followed by 2, 6, or 24 hours of reperfusion. At the beginning of reperfusion, rats were randomly given NBO (95% O2) or room air (21% O2) for 2 hours. In some animals, 3-methyladenine (3-MA, autophagy inhibitor) was administered 10 minutes before reperfusion. The severity of the ischemic injury was determined by infarct volume, neurological deficit, and apoptotic cell death. Western blotting was used to determine the protein expression of autophagy and apoptosis, while mRNA expression of apoptotic molecules was detected by real-time PCR. Results. NBO treatment after ischemia/reperfusion significantly decreased infarct volume and neurobehavioral defects. The increased expression of the autophagy markers, including microtubule-associated protein 1A light chain 3 (LC3) and Beclin 1, after ischemia/reperfusion was reversed by NBO, while promoting Sequestosome 1 (p62/SQSTM1) expression. In addition, NBO reduced cerebral apoptosis in association with alleviated BAX expression and increased BCL-2 expression. 3-MA reduced autophagy and apoptotic death but did not further improve NBO-attenuated ischemic damage. Conclusion. NBO induced remarkable neuroprotection from ischemic injury, which was correlated with blocked autophagy activity.

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