Abstract 1944: Atorvastatin Reduces Intracerebral Hemorrhage after Experimental Stroke

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hazem F Elewa ◽  
Anna Kozak ◽  
David Rychly ◽  
Adviye Ergul ◽  
Reginald Frye ◽  
...  

Ischemic stroke is a leading cause of death and disability in the United States and diabetes mellitus is the fastest growing risk factor for stroke. In addition, hyperglycemia, which is usually associated with diabetes, tends to worsen ischemia/reperfusion injury and to induce more oxidative stress damage. Preliminary data from our laboratory showed that diabetic animals (Goto-Kakizaki rats (GKs) are more susceptible to vascular damage leading to intracerebral hemorrhage. Many studies have indicated that statins possess neuroprotective properties even when administered after the onset of ischemia. However, the acute vascular effects of statins after ischemic stroke have not been studied to date. Objective: to evaluate the efficacy and magnitude of vascular protection of acute statin therapy in both GKs and their normoglycemic controls after experimental ischemic stroke. Methods: Male Wistar (W) and GK rats (270–305 g) underwent 3 hours of middle cerebral artery occlusion (MCAO) followed by reperfusion for 21 hours. Animals were randomized to receive either atorvastatin (15mg/Kg) or methyl cellulose (0.5%), administered by oral gavage, the first dose 5 minutes after reperfusion and the second dose after 12 hours. Brain tissue was analyzed for infarct volume and hemoglobin content. In another set of Wistar rats (n=3), atorvastatin (15mg/Kg) was administered by oral gavage to compare its pharmacokinetic profile with that of humans Results: Atorvastatin-treated groups had significantly lower hemoglobin (p=0.0156) and infarct volume (p=0.0132) compared to their controls. Atorvastatin peak concentration (27–77 ng/ml) in rats’ plasma was found to be similar to that seen after 80mg/day of atorvastatin in humans. Conclusion: Atorvastatin can be a novel vascular protective agent after acute ischemic stroke especially in a high risk population like diabetics. The mechanisms through which these effects are mediated are currently being investigated.

2016 ◽  
Vol 37 (8) ◽  
pp. 2938-2951 ◽  
Author(s):  
Yating He ◽  
Xiaofeng Ma ◽  
Daojing Li ◽  
Junwei Hao

Inflammatory responses are accountable for secondary injury induced by acute ischemic stroke (AIS). Previous studies indicated that O-GlcNAc modification (O-GlcNAcylation) is involved in the pathology of AIS, and increase of O-GlcNAcylation by glucosamine attenuated the brain damage after ischemia/reperfusion. Inhibition of β-N-acetylglucosaminidase (OGA) with thiamet G (TMG) is an alternative option for accumulating O-GlcNAcylated proteins. In this study, we investigate the neuroprotective effect of TMG in a mouse model of experimental stroke. Our results indicate that TMG administration either before or after middle cerebral artery occlusion (MCAO) surgery dramatically reduced infarct volume compared with that in untreated controls. TMG treatment ameliorated the neurological deficits and improved clinical outcomes in neurobehavioral tests by modulating the expression of pro-inflammatory and anti-inflammatory cytokines. Additionally, TMG administration reduced the number of Iba1+ cells in MCAO mice, decreased expression of the M1 markers, and increased expression of the M2 markers in vivo. In vitro, M1 polarization of BV2 cells was inhibited by TMG treatment. Moreover, TMG decreased the expression of iNOS and COX2 mainly by suppressing NF-κB p65 signaling. These results suggest that TMG exerts a neuroprotective effect and could be useful as an anti-inflammatory agent for ischemic stroke therapy.


2020 ◽  
Vol 11 ◽  
Author(s):  
Yang Ye ◽  
Yu-Tian Zhu ◽  
Hong-Xuan Tong ◽  
Jing-Yan Han

Background: Recanalization with tissue plasminogen activator (tPA) is the only approved agent available for acute ischemic stroke. But delayed treatment of tPA may lead to lethal intracerebral hemorrhagic transformation (HT). Numerous studies have reported that immunomodulators have good efficacy on tPA-induced HT in ischemic stroke models. The benefits of immunomodulators on tPA-associated HT are not clearly defined. Here, we sought to conduct a systematic review and meta-analysis of preclinical studies to further evaluate the efficacy of immunomodulators.Methods: The PubMed, Web of Science, and Scopus electronic databases were searched for studies. Studies that reported the efficacy of immunomodulators on tPA-induced HT in animal models of stroke were included. Animals were divided into two groups: immunomodulators plus tPA (intervention group) or tPA alone (control group). The primary outcome was intracerebral hemorrhage, and the secondary outcomes included infarct volume and neurobehavioral score. Study quality was assessed by the checklist of CAMARADES. We used standardized mean difference (SMD) to assess the impact of interventions. Regression analysis and subgroup analysis were performed to identify potential sources of heterogeneity and evaluate the impact of the study characteristics. The evidence of publication bias was evaluated using trim and fill method and Egger’s test.Results: We identified 22 studies that met our inclusion criteria involving 516 animals and 42 different comparisons. The median quality checklist score was seven of a possible 10 (interquartile range, 6–8). Immunomodulators improved cerebral hemorrhage (1.31 SMD, 1.09–1.52); infarct volume (1.35 SMD, 0.95–1.76), and neurobehavioral outcome (0.9 SMD, 0.67–1.13) in experimental stroke. Regression analysis and subgroup analysis indicated that control of temperature and time of assessment were important factors that influencing the efficacy of immunomodulators.Conclusion: Our findings suggested that immunomodulators had a favorable effect on tPA-associated intracerebral hemorrhage, cerebral infarction, and neurobehavioral impairments in animal models of ischemic stroke.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Lindsay Achzet ◽  
Darrell A Jackson

Stroke remains to be a leading cause of disability within the United States. Despite an enormous amount of research effort within the scientific community, very few therapeutics are available for stroke patients. Cytotoxic accumulation of intracellular calcium is a well-studied phenomenon that occurs following ischemic stroke. This intracellular calcium overload results from excessive release of the excitatory neurotransmitter glutamate, a process known as excitotoxicity, eventually leading to delayed neuronal death. The hippocampus is particularly susceptible to AMPA receptor-mediated delayed neuronal death. AMPA receptors (AMPARs) are homo- or hetero-tetramers composed of GluA1-4 subunits. The majority of AMPARs are impermeable to calcium due to a post-transcriptional modification in the channel pore of the GluA2 AMPAR subunit. Calcium-permeable AMPARs lacking the GluA2 subunit, contribute to calcium cytotoxicity and subsequent neuronal death. The internalization and subsequent degradation of GluA2 AMPAR subunits following oxygen-glucose deprivation/reperfusion (OGD/R) is, at least in part, mediated by protein-interacting with C Kinase-1 (PICK1). We hypothesize that disrupting the PICK1—GluA2 interaction will prevent the degradation of GluA2, thereby protecting neurons within the hippocampus from AMPAR-mediated delayed neuronal death. Pretreatment with liposome-encapsulated FSC231, an inhibitor of PICK1, in acute rodent hippocampal slices prevents the OGD/R-induced association of PICK1—GluA2. FSC231 treatment during OGD/R rescues total GluA2 AMPAR subunit protein levels. This work is the first to utilize a liposomal drug delivery system for the delivery of a small molecule in ex vivo acute rodent hippocampal slices exposed to ischemia/reperfusion injury. These results suggest that the interaction between GluA2 and PICK1 serves as an important step in the ischemic/reperfusion-induced reduction in total GluA2 levels and is a potential therapeutic target for the treatment of ischemic stroke.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Shadi Yaghi ◽  
Eva Mistry ◽  
Adam H De Havenon ◽  
Christopher Leon Guerrero ◽  
Amre Nouh ◽  
...  

Background and Purpose: Multiple studies have established that intravenous thrombolysis with alteplase improves outcome after acute ischemic stroke. However, assessment of thrombolysis’ efficacy in stroke patients with atrial fibrillation (AF) has yielded mixed results. We sought to determine the association of alteplase with mortality, hemorrhagic transformation (HT), infarct volume, and mortality in patients with AF and acute ischemic stroke. Methods: We retrospectively analyzed consecutive acute ischemic stroke patients with AF included in the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study, which pooled data from 8 comprehensive stroke centers in the United States. 1889 (90.6%) had available 90-day follow up data and were included. For our primary analysis we used a cohort of 1367/1889 (72.4%) patients who did not undergo mechanical thrombectomy (MT). Secondary analyses were repeated in the patients that underwent MT (n=522). Binary logistic regression was used to determine whether alteplase use was independently associated with risk of HT, final infarct volume, and 90-day mortality, respectively, adjusting for potential confounders. Results: In our primary analyses we found that alteplase use was independently associated with an increased risk for HT (adjusted OR 2.14, 95% CI 1.49 - 3.07, p <0.001) but overall reduced risk of 90-day mortality (adjusted OR 0.58, 95% CI 0.39 - 0.87, p = 0.009). Among patients undergoing MT, alteplase use was associated with a trend towards a reduction in 90-day mortality (adjusted OR 0.68 95% CI 0.45 - 1.04, p = 0.077). In the subgroup of patients prescribed DOAC treatment (n = 327; 24 received alteplase), alteplase treatment was associated with a trend towards smaller infarct size (< 10 mL), (adjusted OR 0.40, 95% CI 0.15 - 1.12, p = 0.082) without a significant difference in the odds of 90-day mortality (adjusted OR 0.51, 95% CI 0.12 - 2.13, p = 0.357) or hemorrhagic transformation (adjusted OR 0.27, 95% CI 0.03 - 2.07, p = 0.206). Conclusion: Thrombolysis with intravenous alteplase was associated with reduced 90-day mortality in AF patients with acute ischemic stroke not undergoing MT. Further study is required to assess the safety and efficacy of alteplase in AF patients undergoing MT and those on DOACs.


2018 ◽  
Vol 48 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Qingqing Wang ◽  
Chengmei Lv ◽  
Yongxin Sun ◽  
Xu Han ◽  
Shan Wang ◽  
...  

Background/Aims: Ischemic stroke results in increased cerebral infarction, neurological deficits and neuroinflammation. The underlying mechanisms involving the anti-inflammatory and neuroprotective properties of α-Lipoic acid (α-LA) remain poorly understood. Herein, we investigated the potential role of α-LA in a middle cerebral artery occlusion (MCAO) rat model and an in vitro lipopolysaccharide (LPS)-induced microglia inflammation model. Methods: In the in vivo study, infarct volume was examined by TTC staining and Garcia score was used to evaluate neurologic recovery. The cytokines were evaluated by enzyme-linked immunosorbent assay, and protein expression of microglia phenotype and NF-κB were measured using western blot. In the in vitro study, the expressions of microglia M1/M2 phenotype were evaluated using qRT-PCR, and immunofluorescence staining was used to assess the nuclear translocation of NF-κB. Results: Both 20 mg/kg and 40 mg/kg of α-LA alleviated infarct size, brain edema, and neurological deficits. Furthermore, α-LA induced the polarization of microglia to the M2 phenotype, modulated the expression of IL-1β, IL-6, TNF-α and IL-10, and attenuated the activation of NF-κB after MCAO. α-LA inhibited the expression of M1 markers, increased activation of the M2 markers, and suppressed the nuclear translocation of NF-κB in LPS-stimulated BV2 microglia. Conclusions: α-LA improved neurological outcome in experimental stroke via modulating microglia M1/M2 polarization. The potential mechanism of α-LA might be mediated by inhibition of NF-κB activation via regulating phosphorylation and nuclear translocation of p65.


2010 ◽  
Vol 30 (7) ◽  
pp. 1306-1317 ◽  
Author(s):  
Vanessa H Brait ◽  
Katherine A Jackman ◽  
Anna K Walduck ◽  
Stavros Selemidis ◽  
Henry Diep ◽  
...  

Cerebral infarct volume is typically smaller in premenopausal females than in age-matched males after ischemic stroke, but the underlying mechanisms are poorly understood. In this study we provide evidence in mice that this gender difference only occurs when the ischemic brain is reperfused. The limited tissue salvage achieved by reperfusion in male mice is associated with increased expression of proinflammatory proteins, including cyclooxygenase-2 (Cox-2), Nox2, and vascular cell adhesion molecule-1 (VCAM-1), and infiltration of Nox2-containing T lymphocytes into the infarcted brain, whereas such changes are minimal in female mice after ischemia–reperfusion (I-R). Infarct volume after I-R was no greater at 72 h than at 24 h in either gender. Infarct development was Nox2 dependent in male but not in female mice, and Nox2 within the infarct was predominantly localized in T lymphocytes. Stroke resulted in an ∼15-fold increase in Nox2-dependent superoxide production by circulating, but not spleen-derived, T lymphocytes in male mice, and this was ∼sevenfold greater than in female mice. These circulating immune cells may thus represent a major and previously unrecognized source of superoxide in the acutely ischemic and reperfused brain of males (and potentially in postmenopausal females). Our findings provide novel insights into mechanisms that could be therapeutically targeted in acute ischemic stroke patients who receive thrombolysis therapy to induce cerebral reperfusion.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fangfang Zhao ◽  
Haiping Zhao ◽  
Junfen Fan ◽  
Rongliang Wang ◽  
Ziping Han ◽  
...  

ObjectiveBy exploring the effects of miR-29a-5p knockout on neurological damage after acute ischemic stroke, we aim to deepen understanding of the molecular mechanisms of post-ischemic injury and thus provide new ideas for the treatment of ischemic brain injury.MethodsmiR-29a-5p knockout rats and wild-type SD rats were subjected to transient middle cerebral artery occlusion (MCAO). miR-29a levels in plasma, cortex, and basal ganglia of ischemic rats, and in plasma and neutrophils of ischemic stroke patients, as well as hypoxic glial cells were detected by real-time PCR. The infarct volume was detected by TTC staining and the activation of astrocytes and microglia was detected by western blotting.ResultsThe expression of miR-29a-5p was decreased in parallel in blood and brain tissue of rat MCAO models. Besides, miR-29a-5p levels were reduced in the peripheral blood of acute stroke patients. Knockout of miR-29a enhanced infarct volume of the MCAO rat model, and miR-29a knockout showed M1 polarization of microglia in the MCAO rat brain. miR-29a knockout in rats after MCAO promoted astrocyte proliferation and increased glutamate release.ConclusionKnockout of miR-29a in rats promoted M1 microglial polarization and increased glutamate release, thereby aggravating neurological damage in experimental stroke rat models.


2021 ◽  
Author(s):  
Feng Jia ◽  
Shuai Shao ◽  
Yanlin Chen ◽  
Jiansong Zhang ◽  
Dilimulati Dilirebati ◽  
...  

Abstract Background: IS (ischemic stroke) remains to be a global public health burden and urgently demands novel strategies. Hypothermia plays a beneficial role in central nervous system diseases. However, the function of hypothermia in IS has not been elucidated. Here we demonstrated the role of hypothermia in IS and explore the mechanism.Methods: IS phenotype was detected by infarct size and infarct volume as well as brain edema in mice. The neuroinflammation was evaluated by activation of microglial cells and expression of inflammatory genes after ischemia/reperfusion (I/R) and oxygen-glucose deprivation/reperfusion (OGD/R). The apoptosis of neuronal cells was assessed by Tunnel staining, expression of Cleaved Caspase-3 and Bax/Bcl-2, cell viability, and LDH release after I/R and OGD/R. Blood-brain-barrier (BBB) permeability was calculated by Evans blue extravasation, the expression of tight junction proteins and MMP-9, cell viability, and LDH release after I/R and OGD/R. The expression of peroxisome-proliferator-activated-receptor gamma (PPARγ) was detected by western blotting after I/R and OGD/R.Results:Hypothermia significantly reduced the infarct size and infarct volume as well as brain edema after ischemia/reperfusion. Consistency, hypothermia induced attenuated neuroinflammation, apoptosis of neuronal cells, and BBB disruption after I/R and OGD/R. Mechanistic studies revealed that hypothermia protected against IS by upregulating the expression of PPARγ in microglial cells, the effect of hypothermia was reversed by GW9662, a PPARγ inhibitor. Conclusions:Our data showed that hypothermia inhibited the activation of microglial cells and microglial cell-mediated neuroinflammation by upregulating the expression of PPARγ in microglial cells. Targeting hypothermia may be a feasible approach for IS treatment.


Author(s):  
Hassan Rakhshandeh ◽  
Samira Asgharzade ◽  
Mohammad Bagher Khorrami ◽  
Fatemeh Forouzanfar

Background: Ischemic stroke is a serious public health problem. Despite extensive research focusing on the area, little is known about novel treatments. Objective: In this study, we aimed to investigate the effects of Capparis spinosa (C. spinosa) extract in the middle cerebral artery occlusion (MCAO) model of ischemic stroke. Methods: Wistar rats underwent 30-min MCAO-induced brain ischemia followed by 24 h of reperfusion. C. spinose was administrated orally once a day for 7 days before the induction of MCAO. The neurologic outcome, infarct volume (TTC staining), histological examination, and markers of oxidative stress, including total thiol content and malondialdehyde (MDA) levels, were measured 24 hr. after the termination of MCAO. Results: Pretreatment with C. spinosa, reduced neurological deficit score, histopathological alterations, and infarct volume in treated groups compared to stroke group. Furthermore, pretreatment with C. spinosa extract significantly reduced the level of MDA with concomitant increases in the levels of thiol in the brain tissues compared with the stroke group. Conclusion: Our study demonstrates that C. spinosa extract effectively protects MCAO injury through attenuation of suppressing oxidative stress.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Mushfiquddin Khan ◽  
Tajinder S Dhammu ◽  
Fumiyo Matsuda ◽  
Inderjit Singh ◽  
Avtar K Singh

Background: In stroke patients, the stimulation of neurorepair mechanisms is necessary to reduce morbidity and disability. Our studies on brain and spinal cord trauma show that an exogenous treatment with the S-nitrosylating agent S-nitrosoglutathione (GSNO) stimulates neurorepair and aids functional recovery. Using a rat model of cerebral ischemia reperfusion (IR), we tested the hypothesis that GSNO invokes the neurorepair process and improves neurobehavioral functions through the angiogenic HIF-1α/VEGF pathway. Methods: Stroke was induced by middle cerebral artery occlusion for 60 min followed by reperfusion in adult male rats. The injured animals were treated with vehicle (IR group, n=7), GSNO (0.25 mg/kg, GSNO group, n=7), and GSNO plus the HIF-1α inhibitor 2-mthoxyestradiol (0.25 mg/kg GSNO+5.0 mg/kg ME, GSNO+ME group, n=7). The groups were studied for 14 days to determine neurorepair mechanisms and functional recovery. Brain capillary endothelial cells were used to show that GSNO promotes angiogenesis and that GSNO-mediated induction of VEGF and the stimulation of angiogenesis are dependent on HIF-1α activity. Results: GSNO treatment of IR enhanced the expression of HIF-1α, VEGF, and PECAM-1. This GSNO treatment also led to increased expression of neurorepair mediators including BDNF. Increased expression of VEGF/BDNF and the degree of tube formation (angiogenesis) by GSNO were reduced in an endothelial cell culture model after the inhibition of HIF-1α by ME. ME treatment of the GSNO group also blocked not only GSNO’s effect of reduced infarct volume (p<0.05) and enhanced expression of PECAM-1but also its improvement of motor and neurological functions (p<0.001). Conclusions: GSNO shows therapeutic promise for stroke by stimulating the process of neurorepair and aiding functional recovery through the HIF-1α/VEGF/PECAM-1 dependent pathway.


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