Abstract 496: Genetic Neutrophil Deficiency Ameliorates Cerebral Ischemia-Reperfusion Injury

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Ryan A Frieler ◽  
Yutein Chung ◽  
Jianrui Song ◽  
Thomas M Vigil ◽  
Richard M Mortensen

Background: Neutrophils respond rapidly to cerebral ischemia and are thought to contribute to inflammation-mediated injury during stroke. Neutralizing antibodies and inhibition of neutrophil chemotactic molecules can be protective during models of stroke, but many of these techniques have the potential to result in cross-reactivity and non-specificity with other immune cell types. Using myeloid Mcl1 knockout mice as a model of genetic neutrophil deficiency, we investigated the contribution of neutrophils to stroke pathophysiology. Methods: Myeloid Mcl1 knockout mice were subjected to transient 90-min middle cerebral artery occlusion and infarct size was assessed by MRI after 24 hours reperfusion. Immune cell mobilization and infiltration was assessed by flow cytometry after 24 hours reperfusion. Results: We found that myeloid Mcl1 knockout mice had significantly reduced infarct size when compared to heterozygous and wild type control mice (MyMcl1 +/+ : 78.0 mm 3 ; MyMcl1 +/- : 83.4 mm 3 ; MyMcl1 -/- : 55.1 mm 3 ). This was accompanied by a nearly complete absence of neutrophils in the ischemic hemisphere of myeloid Mcl1 knockout mice. Although myeloid Mcl1 knockout mice were protected from cerebral infarction, no significant differences in the expression of inflammatory genes were detected. Inhibition of neutrophil chemotaxis using CXCR2 pepducin treatment partially reduced neutrophil mobilization and recruitment to the brain after stroke, but did not reduce infarct size 24 hours after transient MCA occlusion. Conclusions: These data confirm that neutrophils have an important role in infarct development during stroke pathophysiology and suggest that complete deficiency, but not partial inhibition, is necessary to prevent neutrophil-mediated injury during stroke.

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.


Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.


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 ◽  
Vol 115 (5) ◽  
Author(s):  
Manuel Lobo-Gonzalez ◽  
Carlos Galán-Arriola ◽  
Xavier Rossello ◽  
Maribel González‐Del‐Hoyo ◽  
Jean Paul Vilchez ◽  
...  

Abstract Early metoprolol administration protects against myocardial ischemia–reperfusion injury, but its effect on infarct size progression (ischemic injury) is unknown. Eight groups of pigs (total n = 122) underwent coronary artery occlusion of varying duration (20, 25, 30, 35, 40, 45, 50, or 60 min) followed by reperfusion. In each group, pigs were randomized to i.v. metoprolol (0.75 mg/kg) or vehicle (saline) 20 min after ischemia onset. The primary outcome measure was infarct size (IS) on day7 cardiac magnetic resonance (CMR) normalized to area at risk (AAR, measured by perfusion computed tomography [CT] during ischemia). Metoprolol treatment reduced overall mortality (10% vs 26%, p = 0.03) and the incidence and number of primary ventricular fibrillations during infarct induction. In controls, IS after 20-min ischemia was ≈ 5% of the area AAR. Thereafter, IS progressed exponentially, occupying almost all the AAR after 35 min of ischemia. Metoprolol injection significantly reduced the slope of IS progression (p = 0.004 for final IS). Head-to-head comparison (metoprolol treated vs vehicle treated) showed statistically significant reductions in IS at 30, 35, 40, and 50-min reperfusion. At 60-min reperfusion, IS was 100% of AAR in both groups. Despite more prolonged ischemia, metoprolol-treated pigs reperfused at 50 min had smaller infarcts than control pigs undergoing ischemia for 40 or 45 min and similar-sized infarcts to those undergoing 35-min ischemia. Day-45 LVEF was higher in metoprolol-treated vs vehicle-treated pigs (41.6% vs 36.5%, p = 0.008). In summary, metoprolol administration early during ischemia attenuates IS progression and reduces the incidence of primary ventricular fibrillation. These data identify metoprolol as an intervention ideally suited to the treatment of STEMI patients identified early in the course of infarction and requiring long transport times before primary angioplasty.


2004 ◽  
Vol 286 (5) ◽  
pp. H1649-H1653 ◽  
Author(s):  
Yiru Guo ◽  
Adam B. Stein ◽  
Wen-Jian Wu ◽  
Wei Tan ◽  
Xiaoping Zhu ◽  
...  

Although carbon monoxide (CO) has traditionally been viewed as a toxic gas, increasing evidence suggests that it plays an important homeostatic and cytoprotective role. Its therapeutic use, however, is limited by the side effects associated with CO inhalation. Recently, transition metal carbonyls have been shown to be a safe and effective means of transporting and releasing CO groups in vivo. The goal of the present study was to test whether a water-soluble CO-releasing molecule, tricarbonylchloro(glycinato) ruthenium (II) (CORM-3), reduces infarct size in vivo when given in a clinically relevant manner, i.e., at the time of reperfusion. Mice were subjected to a 30-min coronary artery occlusion followed by 24 h of reperfusion and were given either CORM-3 (3.54 mg/kg as a 60-min intravenous infusion starting 5 min before reperfusion) or equivalent doses of inactive CORM-3, which does not release CO. CORM-3 had no effect on arterial blood pressure or heart rate. The region at risk did not differ in control and treated mice (44.5 ± 3.5% vs. 36.5 ± 1.6% of the left ventricle, respectively). However, infarct size was significantly smaller in treated mice [25.8 ± 4.9% of the region at risk ( n = 13) vs. 47.7 ± 3.8% ( n = 14), P < 0.05]. CORM-3 did not increase carboxyhemoglobin levels in the blood. These results suggest that a novel class of drugs, CO-releasing molecules, can be useful to limit myocardial ischemia-reperfusion injury in vivo.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hitoshi Yui ◽  
Uno Imaizumi ◽  
Hisashi Beppu ◽  
Mitsuhiro Ito ◽  
Munetaka Furuya ◽  
...  

The aim of this experiment was to establish whether verapamil, nicardipine, and nitroglycerin have (1) infarct size-limiting effects and (2) antiarrhythmic effects inin vivorabbit hearts during ischemia/reperfusion. Rabbits received regional ischemia by 30 min of left anterior descending coronary artery occlusion followed by 3 hours of reperfusion under ketamine and xylazine anesthesia. The animals were randomly assigned to the following 4 treatment groups: a control group, a verapamil group, a nicardipine group, and a nitroglycerin group. A continuous infusion of verapamil, nicardipine, or nitroglycerin was initiated 5 min prior to ischemia. Infarct size/area at risk decreased in verapamil, and nitroglycerin. The incidence of ischemia-induced arrhythmia decreased in nicardipine, verapamil and nitroglycerin. The incidence of reperfusion-induced arrhythmias decreased in verapamil and nitroglycerin. From the present experimental results, verapamil and nitroglycerin rather than nicardipine did afford significant protection to the heart subjected to ischemia and reperfusion in a rabbit model.


2010 ◽  
Vol 112 (5) ◽  
pp. 1136-1145 ◽  
Author(s):  
Yasuo M. Tsutsumi ◽  
Yoshitaka Kawaraguchi ◽  
Yousuke T. Horikawa ◽  
Ingrid R. Niesman ◽  
Michael W. Kidd ◽  
...  

Background Caveolae are small, flask-like invaginations of the plasma membrane. Caveolins are structural proteins found in caveolae that have scaffolding properties to allow organization of signaling. The authors tested the hypothesis that delayed cardiac protection induced by volatile anesthetics is caveolae or caveolin dependent. Methods An in vivo mouse model of ischemia-reperfusion injury with delayed anesthetic preconditioning (APC) was tested in wild-type, caveolin-1 knockout, and caveolin-3 knockout mice. Mice were exposed to 30 min of oxygen or isoflurane and allowed to recover for 24 h. After 24 h recovery, mice underwent 30-min coronary artery occlusion followed by 2 h of reperfusion at which time infarct size was determined. Biochemical assays were also performed in excised hearts. Results Infarct size as a percent of the area at risk was reduced by isoflurane in wild-type (24.0 +/- 8.8% vs. 45.1 +/- 10.1%) and caveolin-1 knockout mice (27.2 +/- 12.5%). Caveolin-3 knockout mice did not show delayed APC (41.5 +/- 5.0%). Microscopically distinct caveolae were observed in wild-type and caveolin-1 knockout mice but not in caveolin-3 knockout mice. Delayed APC increased the amount of caveolin-3 protein but not caveolin-1 protein in discontinuous sucrose-gradient buoyant fractions. In addition, glucose transporter-4 was increased in buoyant fractions, and caveolin-3/glucose transporter-4 colocalization was observed in wild-type and caveolin-1 knockout mice after APC. Conclusions These results show that delayed APC involves translocation of caveolin-3 and glucose transporter-4 to caveolae, resulting in delayed protection in the myocardium.


2015 ◽  
Vol 35 (4) ◽  
pp. 536-542 ◽  
Author(s):  
Fang Hua ◽  
Huiling Tang ◽  
Jun Wang ◽  
Megan C Prunty ◽  
Xiaodong Hua ◽  
...  

Toll-like receptor 4 (TLR4) contributes to cerebral ischemia/reperfusion (I/R) injury and is a potential target for the treatment of ischemic stroke. This experiment is to evaluate the effect of an exogenous TLR4 antagonist, TAK-242, against acute cerebral I/R injury. A mouse model of cerebral I/R was induced by transient middle cerebral artery occlusion. TAK-242 (3 mg/kg body weight) was injected intraperitoneally 1 hour after ischemia. Our results showed that the concentration of TAK-242 in plasma increased to 52.0 ng/mL 3 hours after injection, was maintained at 54.1 ng/mL 8 hours after injection, and decreased to 22.6 ng/mL 24 hours after injection. The concentration of TAK-242 in brain tissue increased to 26.1 ng/mL in ischemic hemisphere and 14.2 ng/mL in nonischemic hemisphere 3 hours after injection, and was maintained at the similar levels 24 hours after injection. We found that TAK-242 significantly reduced cerebral infarction compared with vehicle control, improved neurologic function, inhibited the phosphorylation of downstream protein kinases in TLR4 signaling pathway, and downregulated the expression of inflammatory cytokines. We conclude that TAK-242 is able to cross blood-brain barrier, blocks TLR4 signaling, mediates the expression of inflammatory cytokines, and protects the brain from acute damage induced by I/R.


2016 ◽  
Vol 94 (11) ◽  
pp. 1187-1192 ◽  
Author(s):  
Mengyang Shui ◽  
Xiaoyan Liu ◽  
Yuanjun Zhu ◽  
Yinye Wang

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.


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