Abstract W P369: Inhibitory Effect of FTY720 on Neuroinflammation in Cerebral Ischemia-reperfusion

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Haoliang Xu ◽  
Pratik Shah ◽  
Dale Pelligrino ◽  
Fernando D Testai

Background: Neuroinflammation is a key contributor to brain injury in cerebral ischemia-reperfusion (CIR). FTY720 has been shown to be neuroprotective in animal stroke models. In most studies, FTY720 treatment was initiated either before or shortly after the cerebral insult. The goal of this study is to investigate the effect of FTY720 on CIR-associated neuroinflammation and outcome using a therapeutic window similar to the one utilized in clinical practice. Methods: We used the rat middle cerebral artery (MCA) occlusion model for CIR. The right MCA was occluded for 1h followed by reperfusion. Animals were treated with vehicle or 0.5 mg/kg FTY720 intraperitoneally at 3h post-reperfusion. Neurobehavioral test battery (scale from 0 to 21 points with lower scores representing increased neurological deficits), grid-walking test, infarct volume, and brain water content were determined 24h post CIR. A cranial window was established at 24h post occlusion and leukocyte trafficking behavior was monitored by direct microscopic observation of surface venules. Pial venular leukocyte adhesion was expressed as the % of vascular area occupied by adherent rhodamine-6G-labeled leukocytes. Statistical analysis was performed by t test. Results: Compared to the vehicle group (n=10), FTY720 animals (n=10) had improved neurological score (8.6±1.9 vs. 13.7±1.9; p<0.001) and better motor performance throughout all subsections of the grid test (p<0.001). FTY720 treatment also decreased infarct volume (vehicle: 342±182; FTY720: 122±138 mm 3 ; p=0.04) and ipsilateral brain edema, measured as water content (vehicle: 84.5±1.05%; FTY720: 79.4±0.87%, p=0.003). Leukocyte trafficking study showed a significant increase in vascular leukocyte adhesion 24 h post reperfusion in the vehicle group which was markedly decreased by FTY720 treatment (sham: 3.0±0.6%; vehicle: 11.4±2.6%; FTY720: 5.2±1.4%; p<0.001). Conclusion: FTY720 given at 3h post reperfusion reduces infarct volume, brain edema, neurological disability, and vascular leukocyte adhesion. These results support the beneficial effect of FTY720 when used in a clinically relevant timeframe and provides direct evidence of the anti-inflammatory effect of FTY720 on CIR.

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Lin Lu ◽  
Hui-qin Li ◽  
Ji-huang Li ◽  
Ai-ju Liu ◽  
Guo-qing Zheng

Sanhua decoction (SHD) is a famous classic Chinese herbal prescription for ischemic stroke, and aquaporin 4 (AQP4) is reported to play a key role in ischemic brain edema. This study aimed to investigate neuroprotection of SHD against focal cerebral ischemia/reperfusion (I/R) injury in rats and explore the hypothesis that AQP4 probably is the target of SHD neuroprotection against I/R rats. Lentiviral-mediated AQP4-siRNA was inducted into adult male Sprague-Dawley rats via intracerebroventricular injection. The focal cerebral ischemia/reperfusion model was established by occluding middle cerebral artery. Neurological examinations were performed according to Longa Scale. Brain water content, was determined by wet and dry weight measurement. Western blot was adopted to test the AQP4 expression in ipsilateral hippocampus. After the treatment, SHD alleviated neurological deficits, reduced brain water content and downregulated the expression of AQP4 at different time points following I/R injury. Furthermore, neurobehavioral function and brain edema after I/R were significantly attenuated via downregulation of AQP4 expression when combined with AQP4-siRNA technology. In conclusion, SHD exerted neuroprotection against focal cerebral I/R injury in rats mainly through a mechanism targeting AQP4.

2021 ◽  
pp. 096032712110361
Hai-Tao Zhang ◽  
Xi-Zeng Wang ◽  
Qing-Mei Zhang ◽  
Han Zhao

Objective To explore the mechanism of chromobox 7 (CBX7)-mediated nuclear factor E2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) signaling pathway in the cerebral ischemia/reperfusion (I/R) injury. Methods The experimental wild-type (WT) and CBX7-/- mice were used to establish cerebral I/R models using the middle cerebral artery occlusion (MCAO) surgery to determine CBX7 levels at different time points after MCAO injury. For all mice, neurological behavior, infarct size, water content, and oxidative stress–related indicators were determined, and transferase (TdT)-mediated dUTP-biotin nick-end labeling (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)) staining method was employed to observe cell apoptosis, while Western blot to measure the expression of CBX7 and Nrf/HO-1 pathway-related proteins. Results At 6 h, 12 h, 24 h, 3 days, and 7 days after mice with MCAO, CBX7 expression was gradually up-regulated and the peak level was reached at 24 h. Mice in the WT + MCAO group had increased infarct size, with significant increases in the modified neurological severity scores and water content in the brain, as well as the quantity of TUNEL-positive cells. For the oxidative stress-indicators, an increase was seen in the content of MDA (malondial dehyde), but the activity of SOD (superoxide dismutase) and content of GSH-PX (glutathione peroxidase) and CAT (catalase) were decreased; meanwhile, the protein expression of CBX7, HO-1, and nuclear Nrf2 was up-regulated, while the cytoplasmic Nrf2 was down-regulated. Moreover, CBX7 knockout attenuated I/R injury in mice. Conclusion Knockout of CBX7 may protect mice from cerebral I/R injury by reducing cell apoptosis and oxidative stress, possibly via activating the Nrf2/HO-1 pathway.

2021 ◽  
Vol 19 (1) ◽  
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.

2020 ◽  
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.

2019 ◽  
Vol 77 (1) ◽  
pp. 39-46 ◽  
Weizhuo Lu ◽  
Ling Xv ◽  
Jiyue Wen

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.

2010 ◽  
Vol 38 (03) ◽  
pp. 517-527 ◽  
Yan-Yan Yin ◽  
Wei-Ping Li ◽  
Hui-Ling Gong ◽  
Fen-Fang Zhu ◽  
Wei-Zu Li ◽  

This study was to observe the neurological protective effects of astragalosides (AST) on focal cerebral ischemia-reperfusion (I/R) injury in rats and to explore its possible mechanism. Male SD rats received right middle cerebral artery occlusion for 120 min and AST (40 mg/kg) was orally administered. The rats were decapitated 1, 3, 7, and 14 days after reperfusion. The neurological deficit score, infarct volume and water content of brain were measured; the activity of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and nitric oxide synthase (NOS), and the content of malondialdehyde (MDA), lactate (LD) and nitric oxide (NO) of brain tissue were detected too. The expression of inducible nitric synthase (iNOS), nerve growth factor (NGF) and tropomyosin receptor kinase A (TrkA) mRNA were measured by RT-PCR or real-time PCR. AST could significantly reduce the neurological deficit score; infract volume and water content, increase SOD and LDH activities, decrease NOS activity and MDA, LD and NO content. AST treatment could down-regulate expression of iNOS mRNA, while, NGF and TrkA mRNA were up-regulated. Our data suggest that AST have the protective effects on focal cerebral ischemia in rats at the different reperfusion time points, the mechanism may be related to the antioxidation, regulated the expressions of iNOS, NGF and TrkA mRNA.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9042
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.

2021 ◽  
Ke Wang ◽  
Lin Qin He ◽  
Xiao Yu Yang ◽  
Hai Hong Huang ◽  
Wen Long Liu ◽  

Abstract Objective To prepare borneol angelica polysaccharide liposomes (BAPLs) with distinct characteristics in Chinese and Western medicine, to explore their effects on anti-cerebral ischemia-reperfusion inflammatory reactions and to explain their mechanism. Methods Under the guidance of the basic theory of traditional Chinese medicine, a new dosage form of nanoliposomes was selected to prepare BAPL by the thin film dispersion ultrasonic method. The effects of angelica polysaccharide (AP), lecithin, cholesterol and ultrasonication time on encapsulation efficiency were investigated. Triphenyltetrazolium chloride (TTC) staining was used to detect the volume of cerebral infarction. Western blotting was used to detect the expression levels of TLR-4, NF-κBp65, ZO-1, ZO-2, IL-1β, IL-6, IL-8 and IL-10. Results As the mass ratio of lecithin to cholesterol (X1), the mass of angelica polysaccharide (X2) and the interaction between X1 and X2 (X1X2) were used as investigation factors, the fitting equation between encapsulation efficiency Y and X was Y=0.307-0.153X1+0.026 X2+0.006X12-0.000301 X22+0.002X1X2 (P<0.05). The best ultrasonication time was 15 min, the highest encapsulation efficiency was 80.4%, the particle size was 179.1 nm, and the surface zeta potential was -17.2 mV. In BAPL group, the infarct volume of TTC staining was significantly decreased (P<0.05), and the expression levels of NF-κBp65, TLR-4, IL-8, IL-6, IL-1β in brain tissue were significantly decreased (P<0.05), while the expression levels of ZO-1, ZO-2, IL-10 were significantly increased (P<0.05). Conclusion BAPL has high encapsulation efficiency, small particle size and stable properties and can alleviate cerebral ischemia-reperfusion injury. Its mechanism may be related to inhibiting inflammatory reactions, downregulating inflammatory reaction signaling pathways and protecting the blood–brain barrier (BBB).

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