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 Preactivation of Notch1 in remote ischemic preconditioning reduces cerebral ischemia-reperfusion injury through crosstalk with the NF-κB pathway

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Weidong Liang ◽  
Chunshui Lin ◽  
Liuqing Yuan ◽  
Li Chen ◽  
Peipei Guo ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Signaling Pathway ◽  
Ischemic Preconditioning ◽  
Neuronal Apoptosis ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Notch1 Signaling Pathway

Abstract Background Remote ischemic preconditioning (RIPC) initiates endogenous protective pathways in the brain from a distance and represents a new, promising paradigm in neuroprotection against cerebral ischemia-reperfusion (I/R) injury. However, the underlying mechanism of RIPC-mediated cerebral ischemia tolerance is complicated and not well understood. We reported previously that preactivation of Notch1 mediated the neuroprotective effects of cerebral ischemic preconditioning in rats subjected to cerebral I/R injury. The present study seeks to further explore the role of crosstalk between the Notch1 and NF-κB signaling pathways in the process of RIPC-induced neuroprotection. Methods Middle cerebral artery occlusion and reperfusion (MCAO/R) in adult male rats and oxygen-glucose deprivation and reoxygenation (OGD/R) in primary hippocampal neurons were used as models of I/R injury in vivo and in vitro, respectively. RIPC was induced by a 3-day procedure with 4 cycles of 5 min of left hind limb ischemia followed by 5 min of reperfusion each day before MCAO/R. Intracerebroventricular DAPT injection and sh-Notch1 lentivirus interference were used to inhibit the Notch1 signaling pathway in vivo and in vitro, respectively. After 24 h of reperfusion, neurological deficit scores, infarct volume, neuronal apoptosis, and cell viability were assessed. The protein expression levels of NICD, Hes1, Phospho-IKKα/β (p-IKK α/β), Phospho-NF-κB p65 (p-NF-κB p65), Bcl-2, and Bax were assessed by Western blotting. Results RIPC significantly improved neurological scores and reduced infarct volume and neuronal apoptosis in rats subjected to I/R injury. OGD preconditioning significantly reduced neuronal apoptosis and improved cell viability after I/R injury on days 3 and 7 after OGD/R. However, the neuroprotective effect was reversed by DAPT in vivo and attenuated by Notch1-RNAi in vitro. RIPC significantly upregulated the expression of proteins related to the Notch1 and NF-κB pathways. NF-κB signaling pathway activity was suppressed by a Notch1 signaling pathway inhibitor and Notch1-RNAi. Conclusions The neuroprotective effect of RIPC against cerebral I/R injury was associated with preactivation of the Notch1 and NF-κB pathways in neurons. The NF-κB pathway is a downstream target of the Notch1 pathway in RIPC and helps protect focal cerebral I/R injury.

Combined Ischemic Preconditioning and Resveratrol Improved Bloodbrain Barrier Breakdown via Hippo/YAP/TAZ Signaling Pathway

2020 ◽  
Vol 18 (9) ◽  
pp. 713-722 ◽  
Author(s):  
Ganji Hong ◽  
Ying Yan ◽  
Yali Zhong ◽  
Jianer Chen ◽  
Fei Tong ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Blood Brain Barrier ◽  
Ischemic Preconditioning ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Cerebral Infarct ◽  
Brain Barrier ◽  
Binding Motif ◽  
Blood Brain ◽  
Barrier Breakdown

Background: Transient Ischemia/Reperfusion (I/R) is the main reason for brain injury and results in disruption of the Blood-Brain Barrier (BBB). It had been reported that BBB injury is one of the main risk factors for early death in patients with cerebral ischemia. Numerous investigations focus on the study of BBB injury which have been carried out. Objective: The objective of this study was to investigate the treatment function of the activation of the Hippo/Yes-Associated Protein (YAP) signaling pathway by combined Ischemic Preconditioning (IPC) and resveratrol (RES) before brain Ischemia/Reperfusion (BI/R) improves Blood-Brain Barrier (BBB) disruption in rats. Methods: Sprague-Dawley (SD) rats were pretreated with 20 mg/kg RES and IPC and then subjected to 2 h of ischemia and 22 h of reperfusion. The cerebral tissues were collected; the cerebral infarct volume was determined; the Evans Blue (EB) level, the brain Water Content (BWC), and apoptosis were assessed; and the expressions of YAP and TAZ were investigated in cerebral tissues. Results: Both IPC and RES preconditioning reduced the cerebral infarct size, improved BBB permeability, lessened apoptosis, and upregulated expressions of YAP and transcriptional co-activator with PDZ-binding motif (TAZ) compared to the Ischemia/Reperfusion (I/R) group, while combined IPC and RES significantly enhanced this action. Conclusion: combined ischemic preconditioning and resveratrol improved blood-brain barrier breakdown via Hippo/YAP/TAZ signaling pathway.

scholarly journals Tissue Kallikrein Alleviates Cerebral Ischemia-Reperfusion Injury by Activating the B2R-ERK1/2-CREB-Bcl-2 Signaling Pathway in Diabetic Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ruifeng Shi ◽  
Kunxiong Yuan ◽  
Bin Hu ◽  
Hongfei Sang ◽  
Lizhi Zhou ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Camp Response Element Binding ◽  
Diabetic Rats ◽  
Tissue Kallikrein ◽  
Inflammatory Reactions ◽  
Beneficial Effects

Diabetes mellitus (DM) substantially increases the risk of ischemic stroke and reduces the tolerance to ischemic insults. Tissue kallikrein (TK) has been demonstrated to protect neurons from ischemia/reperfusion (I/R) injury in orthoglycemic model by activating the bradykinin B2 receptor (B2R). Considering the differential effects of B2R or bradykinin B1 receptor (B1R) on cardioprotection and neuroprotection in I/R with or without diabetes, this study was designed to investigate the role of TK during cerebral I/R injury in streptozotocin-induced diabetic rats. Intravenous injection of TK inhibited apoptosis in neurons, alleviated edema and inflammatory reactions after focal cerebral I/R, significantly reduced the infarct volume, and improved functional recovery. These beneficial effects were accompanied by activation of the extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP response element-binding (CREB), and Bcl-2 signal proteins. Inhibition of the B2R or ERK1/2 pathway abated the effects of TK, whereas an antagonist of B1R enhanced the effects. These findings reveal that the neuroprotective effect of TK against cerebral I/R injury in streptozotocin-induced diabetic rats mainly involves the enhancement of B2R and ERK1/2-CREB-Bcl-2 signaling pathway activity.

scholarly journals Neuroprotective and Anti-Inflammatory Effect of Pterostilbene Against Cerebral Ischemia/Reperfusion Injury via Suppression of COX-2

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenjun Yan ◽  
Dongqing Ren ◽  
Xiaoxue Feng ◽  
Jinwen Huang ◽  
Dabin Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Inflammatory Cytokines ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Polymorphonuclear Leucocyte ◽  
The Body ◽  
Cox 2 ◽  
Anti Inflammatory

Background: The incidence of cerebral ischemia disease leading cause of death in human population worldwide. Treatment of cerebral ischemia remains a clinical challenge for researchers and mechanisms of cerebral ischemia remain unknown. During the cerebral ischemia, inflammatory reaction and oxidative stress plays an important role. The current investigation scrutinized the neuroprotective and anti-inflammatory role of pterostilbene against cerebral ischemia in middle cerebral artery occlusion (MCAO) rodent model and explore the underlying mechanism.Methods: The rats were divided into following groups viz., normal, sham, MCAO and MCAO + pterostilbene (25 mg/kg) group, respectively. The groups received the oral administration of pterostilbene for 30 days followed by MCAO induction. The neurological score, brain water content, infarct volume and Evan blue leakage were estimated. Hepatic, renal, heart, inflammatory cytokines and inflammatory mediators were estimated.Results: Pterostilbene treatment significantly (p &lt; 0.001) improved the body weight and suppressed the glucose level and brain weight. Pterostilbene significantly (p &lt; 0.001) reduced the hepatic, renal and heart parameters. Pterostilbene significantly (p &lt; 0.001) decreased the level of glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and decreased the level of malonaldehyde (MDA), 8-Hydroxy-2′-deoxyguanosine (8-OHdG). Pterostilbene significantly (p &lt; 0.001) inflammatory cytokines and inflammatory parameters such as cyclooxygenase-2 (COX-2), inducible nitric oxidase synthase (iNOS) and prostaglandin (PGE2). Pterostilbene significantly (p &lt; 0.001) down-regulated the level of metalloproteinases (MMP) such as MMP-2 and MMP-9. Pterostilbene suppressed the cellular swelling, cellular disintegration, macrophage infiltration, monocyte infiltration and polymorphonuclear leucocyte degranulation in the brain.Conclusion: In conclusion, Pterostilbene exhibited the neuroprotective effect against cerebral ischemia in rats via anti-inflammatory mechanism.

scholarly journals The neuroprotective effect of pretreatment with carbon dots from Crinis Carbonisatus (carbonized human hair) against cerebral ischemia reperfusion injury

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yue Zhang ◽  
Suna Wang ◽  
Fang Lu ◽  
Meiling Zhang ◽  
Hui Kong ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Carbon Dots ◽  
Ischemia Reperfusion Injury ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Lesion Volume ◽  
Ischemic Lesion ◽  
Tnf Α

Abstract Background Cerebral infarction and cerebral hemorrhage, also known as “stroke”, is one of the leading cause of death. At present, there is no real specific medicine for stroke. Crinis Carbonisatus (named Xue-yu-tan in Chinese), produced from carbonized hair of healthy human, and has been widely applied to relieve pain and treat epilepsy, stroke and other diseases in China for thousands of years. Results In this work, a new species of carbon dots derived from Crinis Carbonisatus (CrCi-CDs) were separated and identified. And the neuroprotective effect of carbon dots from CrCi were evaluated using the middle cerebral artery occlusion (MCAO) model. Neurological deficit score and infarction volume was assessed, evans blue content of ischemic hemispheres was measured, the concentrations of inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) in the cortex were measured, and the levels of neurotransmitters in the brain were determined. Preconditioning of CrCi-CDs significantly reduced ischemic lesion volume and blood–brain-barrier (BBB) permeability, improved neurologic deficits, decreased the level of TNF-α and IL-6 in MCAO rats, inhibited excitatory neurotransmitters aspartate (Asp) and glutamate (Glu), and increased the level of 5-hydroxytryptamine (5-HT). The RNA-Sequencing results reveal that further potential mechanisms behind the activities may be related to the anti-inflammation effects and inhibition of neuroexcitatory toxicity. Conclusion CrCi-CDs performs neuroprotective effect on cerebral ischemia and reperfusion injury, and the mechanisms may correlate with its anti-inflammatory action, which suggested that CrCi-CDs have potential value in clinical therapy on the acute apoplexy cases in combination with thrombolytic drugs. Graphic abstract

scholarly journals Neuroprotective Effect of DAHP via Antiapoptosis in Cerebral Ischemia

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yanhua Qin ◽  
Weiming Hu ◽  
Yang Yang ◽  
Zhiying Hu ◽  
Weiyun Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Brain Injury ◽  
Cerebral Ischemia ◽  
Caspase 3 ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Tunel Staining ◽  
Cox 2

Aberrant production of nitric oxide following inducible nitric oxide synthase (iNOS) expression has been implicated in cell death and contributes to ischemic brain injury. Tetrahydrobiopterin (BH4) is an essential cofactor of NOS activity. Herein, we evaluated antiapoptotic and anti-inflammatory effects of diamino-6-hydroxypyrimidine (DAHP), a guanosine 5′-triphosphate cyclohydrolase 1 (GTPCH1) inhibitor on focal cerebral ischemia-reperfusion injury by middle cerebral artery occlusion and reperfusion (MCAO) and investigated the underlying mechanism. Sprague-Dawley rats were divided into five groups. Experimental groups were subjected to 1.5 h transient MCAO. T2-weighted imaging was performed to evaluate brain edema lesions in the stroke rats. Infarct volume was estimated by 2,3,5-triphenyltetrazolium chloride (TTC) staining after 24 h reperfusion. Western blotting and immunohistochemistry were performed to detect iNOS, caspase-3, Bcl-2, COX-2, and TNF-α protein expressions. Apoptosis was determined by TUNEL staining. T2 hyperintensity changes were observed in primary ischemic region. DAHP pretreatment significantly suppressed iNOS overexpression, caspase-3, and TNF-α. There was also attenuation of neuronal apoptosis with decrement in proteins Bcl-2 and COX-2 expressions. On the basis of our results, we hypothesize DAHP to have a neuroprotective function against focal cerebral ischemia and might attenuate brain injury by decreasing reactive oxygen species (ROS) production, subsequently inhibiting apoptosis.

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 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.

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