scholarly journals Stigmasterol alleviates cerebral ischemia/reperfusion injury by attenuating inflammation and improving antioxidant defenses in rats

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Qilong Liang ◽  
Jun Yang ◽  
Jiaji He ◽  
Xiaoling Chen ◽  
Hong Zhang ◽  
...  

Abstract Background/aims: The paper aimed to investigate the effects of Stigmasterol on inflammatory factors, antioxidant capacity, and apoptotic signaling pathways in brain tissue of rats with cerebral ischemia/reperfusion (I/R) injury. Methods: The neurological deficits of the rats were analyzed and HE staining was performed. The cerebral infarct volume was calculated by means of TTC staining, and neuronal apoptosis was detected by TUNEL staining. At the same time, the contents of glutathione peroxidase, glutathione, superoxide dismutase (SOD), nitric oxide, and malondialdehyde in brain tissue were measured. The expression of the relevant protein was detected by means of Western blotting. Results: The results showed that the neurological deficit score and infarct area of the I/R rats in the soy sterol treatment group were significantly lower than those in the I/R group. Moreover, the levels of carbon monoxide and malondialdehyde in the soysterol group were significantly lower than those in the I/R group, and the expressions of cyclooxygenase-2 (Cox-2) and NF-κB (p65) in the soysterol group were also significantly lower than those in the I/R group. The expression of Nrf2 (nucleus) and heme oxygenase-1 (HO-1) increased significantly, and the activities of antioxidant enzymes and SOD were increased. In addition, the stigmasterol treatment can inhibit apoptosis, down-regulate Bax and cleaved caspase-3 expression, and up-regulate Bcl-Xl expression. Conclusion: Stigmasterol protects the brain from brain I/R damage by reducing oxidative stress and inflammation.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9042
Author(s):  
Jun Wang ◽  
Ming Guo ◽  
Ruojia Ma ◽  
Maolin Wu ◽  
Yamei Zhang

Background & Aims Tetrandrine (Tet) has been reported to have anti-inflammatory effects and protect from the ischemic strokes. The NLRP3 inflammasome plays a key role in cerebral ischemia/reperfusion (I/R)-induced inflammatory lesions. However, the molecular mechanisms of Tet related to the progression of cerebral ischemia are still unclear. Therefore, the aim of this study was to investigate the possible effects of Tet on cerebral ischemia and the related mechanisms involved in NLRP3 inflammasome. Methods C57BL/6J mice used as a cerebral I/R injury model underwent middle cerebral artery occlusion (MCAO) for 2 h following reperfusion for 24 h. Tet (30 mg/kg/day, i.p.) was administered for seven days and 30 min before and after MCAO. Their brain tissues were evaluated for NLRP3 inflammasome and Sirtuin-1 (Sirt-1) expression. An intracerebroventricular injection of Sirt-1 siRNA was administered to assess the activation of the NLRP3 inflammasome. Results Tet significantly reduced the neurological deficits, infarction volume, and cerebral water content in MCAO mice. Moreover, it inhibited I/R-induced over expression of NLRP3, cleaved caspase-1, interleukin (IL)-1β, IL-18, and Sirt-1. Sirt-1 knockdown with siRNA greatly blocked the Tet-induced reduction of neurological severity score and infarct volume, and reversed the inhibition of NLRP3 inflammasome activation. Conclusion Our results demonstrate that Tet has benefits for cerebral I/R injury, which are partially related to the suppression of NLRP3 inflammasome activation via upregulating Sirt-1.


2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Bao-yu Zhang ◽  
Guan-ran Wang ◽  
Wen-hua Ning ◽  
Jian Liu ◽  
Sha Yang ◽  
...  

Background. As one of the first steps in the pathology of cerebral ischemia, glutamate-induced excitotoxicity progresses too fast to be the target of postischemic intervention. However, ischemic preconditioning including electroacupuncture (EA) might elicit cerebral ischemic tolerance through ameliorating excitotoxicity. Objective. To investigate whether EA pretreatment based on TCM theory could elicit cerebral tolerance against ischemia/reperfusion (I/R) injury, and explore its potential excitotoxicity inhibition mechanism from regulating proapoptotic pathway of the NMDA subtype of glutamate receptor (GluN2B). Methods. The experimental procedure included 5 consecutive days of pretreatment stage and the subsequent modeling stage for one day. All rats were evenly randomized into three groups: sham MCAO/R, MCAO/R, and EA+MCAO/R. During pretreatment procedure, only rats in the EA+MCAO/R group received EA intervention on GV20, SP6, and PC6 once a day for 5 days. Model preparation for MCAO/R or sham MCAO/R started 2 hours after the last pretreatment. 24 hours after model preparation, the Garcia neurobehavioral scoring criteria was used for the evaluation of neurological deficits, TTC for the measurement of infarct volume, TUNEL staining for determination of neural cell apoptosis at hippocampal CA1 area, and WB and double immunofluorescence staining for expression and the cellular localization of GluN2B and m-calpain and p38 MAPK. Results. This EA pretreatment regime could improve neurofunction, decrease cerebral infarction volume, and reduce neuronal apoptosis 24 hours after cerebral I/R injury. And EA pretreatment might inhibit the excessive activation of GluN2B receptor, the GluN2B downstream proapoptotic mediator m-calpain, and the phosphorylation of its transcription factor p38 MAPK in the hippocampal neurons after cerebral I/R injury. Conclusion. The EA regime might induce tolerance against I/R injury partially through the regulation of the proapoptotic GluN2B/m-calpain/p38 MAPK pathway of glutamate.


Author(s):  
Jun Ling ◽  
Haijian Cai ◽  
Muya Lin ◽  
Shunli Qi ◽  
Jian Du ◽  
...  

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Bingjin Ou ◽  
Wei Tao ◽  
Songbai Yang ◽  
Jiateng Feng ◽  
Jinfeng Wang ◽  
...  

Geum japonicum Thunb. var. chinense (GJ) is a type of wild vegetable found in China and other Asian countries; it has been reported that its extracts possess a neuroprotective effect against cerebral ischemia reperfusion (CIR) injury. The aim of this study is to explore the effect GJ extracts on transient focal CIR injury and neurons apoptosis and to clarify its possible underlying mechanisms in vivo. Our results indicated that pretreatment with GJ extracts significantly ameliorated the infarct volume, decreased neurological deficits, lessened neural cells apoptosis, downregulated GFAP activity level, and increased surviving neurons. Moreover, GJ extracts preadministration increased Bcl-2 levels and attenuated the increase in the expressions of Bax and it also lowered the cleaved caspase-3 activity in ischemic cortex tissues which was caused by CIR and increased the expression of PI3K and p-Akt. The above effects of high dose of GJ (GJ-H) group were much better than those of low dose of GJ (GJ-L), which indicated that GJ extracts may be helpful in the suppression of CIR injury with a dose-dependent manner.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xueling Zhou ◽  
Wenhao Lu ◽  
You Wang ◽  
Jiani Li ◽  
Yong Luo

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Caihong Deng ◽  
Jun Cao ◽  
Jiangquan Han ◽  
Jianguo Li ◽  
Zhaohun Li ◽  
...  

This study aimed to determine the effect of liraglutide pretreatment and to elucidate the mechanism of nuclear factor erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1) signaling after focal cerebral ischemia injury in diabetic rats model. Adult male Sprague-Dawley rats were randomly divided into the sham-operated (S) group, diabetes mellitus ischemia (DM + MCAO) group, liraglutide pretreatment normal blood glucose ischemia (NDM+MCAO+L) group, and liraglutide pretreatment diabetes ischemia (DM + MCAO + L) group. At 48 h after middle cerebral artery occlusion (MCAO), neurological deficits and infarct volume of brain were measured. Oxidative stress brain tissue was determined by superoxide dismutase (SOD) and myeloperoxidase (MPO) activities. The expression levels of Nrf2 and HO-1 of brain tissue were analyzed by western blotting. In the DM + MCAO + L group, neurological deficits scores and cerebral infarct volume seemed to decrease at 48 h after MCAO cerebral ischemia compared with those in DM + MCAO group (P<0.05). In addition, the expression of Nrf2 and HO-1 increased in 48 h at liraglutide pretreatment groups after MCAO cerebral ischemia if compared with those in the DM + MCAO group (P<0.05). Furthermore, the DM + MCAO + L group has no significant difference compared with the NDM + MCAO + L group (P>0.05). To sum up, alleviating effects of liraglutide on diabetes complicated with cerebral ischemia injury rats would be related to Nrf2/HO-1 signaling pathway.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lin Guo ◽  
Zhixuan Huang ◽  
Lijuan Huang ◽  
Jia Liang ◽  
Peng Wang ◽  
...  

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.


2021 ◽  
Author(s):  
Weifeng Shan ◽  
Huifeng Ge ◽  
Bingquan Chen ◽  
Linger Huang ◽  
Shaojun Zhu ◽  
...  

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.


2020 ◽  
Author(s):  
Peng-Fei Wang ◽  
Wei-Bin Zhong ◽  
Xiao-Hua Ju ◽  
Zhen-Guang LI ◽  
Fa-Xiang Wang

Abstract Objective: Toll-like receptor (TLR) activation plays an important role in cerebral ischemia-reperfusion injury. In addition, increasing evidence suggests that TLRs may affect cognitive behavior through TLR-mediated signaling. Here, we explored the protective effects of TLR3 on cognitive dysfunction after ischemia in the context of poly(I:C) preconditioning.Materials and Methods : Mice (n=84) were randomly divided into the sham group, AAV (vector) group, middle cerebral artery occlusion (MCAO) model group, poly(I:C) (pre) + MCAO model group, and AAV (TRAF6) + poly(I:C) (pre) + MCAO model group. The mice were injected i.p. with poly(I:C) (1.25 mg/g) 24 h prior to cerebral ischemia. Then, neurological scores were assessed, and the infarct volume was measured after cerebral ischemia-reperfusion. We evaluated the poly(I:C) preconditioning-induced attenuation of neuronal damage using Nissl and TUNEL staining. We assessed the poly(I:C) preconditioning-mediated inhibition of I/R-induced glial activation, inflammatory factor levels and TRAF6 expression. We also assessed whether TRAF6 affects poly(I:C) preconditioning to improve cognitive dysfunction and neuroprotection.Results: The results showed that compared with those of the sham group and AAV (vector) group, the functional neurological scores and focal infarct volume of the MCAO group and poly(I:C) preconditioning group were significantly increased. The results also showed that compared with those of the MCAO group, the functional neurological scores and focal infarct volume of the poly(I:C) preconditioning group were significantly reduced. Our results indicated that poly(I:C) preconditioning significantly attenuated neuronal apoptosis and cell loss. Poly(I:C) preconditioning also inhibited I/R-induced glial cell activation and reduced NF-κB, TNF-α and IL-β levels. Our findings showed that poly(I:C) preconditioning affected cognitive dysfunction following cerebral I/R. Here, we observed that poly(I:C) preconditioning affected the expression and distribution of TRAF6 following cerebral I/R. TRAF6 overexpression abolished poly(I:C)-induced neuroprotection and worsened cognitive dysfunction in cerebral I/R injury.Significance: Our findings suggested that poly(I:C) preconditioning ameliorates cognitive dysfunction after cerebral I/R injury by inhibiting TRAF6 signaling, which is a potential therapeutic target for the treatment of cognitive dysfunction after stroke.


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