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目的探讨白藜芦醇预处理对神经干细胞氧糖剥夺损伤的保护作用。方法用含有白藜芦醇的细胞培养基预培养神经干细胞1h,更换低糖培养基后将细胞培养在缺氧培养盒内6h进行氧糖剥夺实验(OGD);采用噻唑蓝(MTI")比色实验检测细胞活性;用LDH试剂盒测细胞培养基中乳酸脱氢酶(LDH)活性。结果白藜芦醇预处理(PRC)组细胞MTT值高于对照组(n=7,P〈0.01),PRC组细胞培养基上清中LDH低于对照组(n=5,P〈0.01)。结论白藜芦醇预处理对神经干细胞氧糖剥夺损伤有保护作用。  相似文献   

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We have previously shown that tissue plasminogen activator (tPA) participates in the neurotoxicity of microglial conditioned medium (MgCM). Killing of hippocampal neurons by MgCM was prevented by both plasminogen activator inhibitor-1 (PAI-1) and anti-tPA antibody. An N-methyl-D-aspartate (NMDA) receptor blocker protected neurons from MgCM, suggesting that this subtype of glutamate receptor is involved. Whereas glutamate receptor-mediated events are important in cerebral ischemia and tPA has previously been shown to enhance excitotoxicity in hippocampus, we hypothesized that tPA would exaggerate oxygen glucose deprivation (OGD) injury in cultures of hippocampal neurons. Dissociated rat hippocampal cells were grown under conditions designed to optimize neuronal growth while minimizing glial replication. At 7--10 days, cultures were subjected to OGD for 2.5 hr. Recombinant human tPA (1,000 IU) was added immediately after OGD. Viability was assessed 24 hr later. Viable, apoptotic, and necrotic cells were classified and quantified based on staining patterns of acridine orange and ethidium bromide under fluorescence microscopy. tPA alone did not alter neuronal integrity. OGD produced significant neuronal death (viability reduced by 45%, P < 0.001). tPA completely protected OGD-exposed cultures. Potential mechanisms of tPA protection were explored. Whereas tPA antibody abolished the protective effect of tPA, its proteolytic inhibitor PAI-1 did not alter the effect. The effect of tPA was tested in separate free radical and excitatory amino acid insults. It did not protect neurons from hydrogen peroxide (1 microM), S-nitro-acetylpenicillamine (10 microM), glutamate (50 microM), or NMDA (10 microM) damage but significantly attenuated injury caused by 250 microM kainate. We conclude that tPA is capable of protecting hippocampal neurons from OGD by a nonproteolytic action. The mechanism of protection was not defined, although attenuation of AMPA/kainate glutamate receptors may play a role.  相似文献   

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J Zhou  Y Fu  X C Tang 《Neuroreport》2001,12(10):2073-2077
The effect of huperzine A (HupA) on oxygen-glucose deprivation (OGD)-induced injury was investigated in the rat pheochromocytoma cell line PC12. OGD for 3 h and reoxygenation for 24 h triggered apoptosis characterized by chromatin condensation, nucleus fragmentation and DNA laddering. The temporal profile of c-jun, p53, bcl-2 and bax mRNA after OGD indicated that these genes played important roles in apoptosis. Pre-incubation of the cells for 2 h with 1 microM HupA significantly attenuated apoptosis. The same treatment also reduced the up-regulation of c-jun and bax as well as the down-regulation of bcl-2. These data suggest the ability of HupA to attenuate apoptosis induced by OGD may result from its capability to alter the expression of apoptosis-related genes.  相似文献   

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IntroductionPerampanel is a highly selective and noncompetitive α‐amino‐3 ‐hydroxy‐5‐methyl‐4‐isoxazole propionate receptor (AMPAR) antagonist, which has been used as an orally administered antiepileptic drug in more than 55 countries. Recently, perampanel was shown to exert neuroprotective effects in hemorrhagic and ischemic stroke models via regulating blood–brain barrier (BBB) function.AimHere, the protective effects of perampanel were investigated in an in vitro neurovascular unit (NVU) system established using a triple cell co‐culture model (neurons, astrocytes, and brain microvascular endothelial cells) and in an in vivo traumatic brain injury (TBI) model.ResultsNeurons in the NVU system exhibit a more mature morphological phenotype compared with neurons cultured alone, and the co‐culture system mimicked an impermeable barrier in vitro. Perampanel protects the NVU system against traumatic and excitotoxic injury, as evidenced by reduced lactate dehydrogenase (LDH) release and apoptotic rate. Treatment with perampanel attenuated lipid peroxidation and expression of inflammatory cytokines. In addition, perampanel increased Sirt3 protein expression, enhanced the activities of mitochondrial enzyme IDH2 and SOD2, and preserved BBB function in vitro. Knockdown of Sirt3 using specific siRNA (Si‐Sirt3) partially reserved the effects of perampanel on neuronal injury and BBB function. Treatment with perampanel in vivo attenuated brain edema, preserved neurological function, inhibited apoptosis and microglia activation after TBI. Furthermore, perampanel increased the expression of Sirt3 and preserved BBB function after TBI. The effect of perampanel on BBB function and brain edema was abolished by knockdown of Sirt3 in vivo.ConclusionOur results indicate that the noncompetitive AMPAR antagonist perampanel protects the NVU system and reduces brain damage after TBI via activating the Sirt3 cascades.  相似文献   

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Autophagy has been shown to have a protective effect against brain damage. Ligustilide(LIG) is a bioactive substance isolated from Ligusticum chuanxiong, a traditional Chinese medicine. LIG has a neuroprotective effect; however, it is unclear whether this neuroprotective effect involves autophagy. In this study, PC12 cells were treated with 1 × 10–5–1 × 10–9 M LIG for 0, 3, 12 or 24 hours, and cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium(MTS) assay. Treatment with 1 × 10–6 M LIG for 3 hours had the greatest effect on cell proliferation, and was therefore used for subsequent experiments. PC12 cells were pre-treated with 1 × 10–6 M LIG for 3 hours, cultured in 95% N2/5% CO2 in Dulbecco's modified Eagle's medium without glucose or serum for 4 hours, and then cultured normally for 16 hours, to simulate oxygen-glucose deprivation/reoxygenation(OGD/R). Cell proliferation was assessed with the MTS assay. Apoptosis was detected by flow cytometry. The expression levels of apoptosis-related proteins, Bcl-2 and Bax, autophagy-related proteins, Beclin 1 and microtubule-associated protein l light chain 3 B(LC3-II), and liver kinase B1(LKB1)-5′-adenosine monophosphate-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR) signaling pathway-related proteins were assessed by western blot assay. Immunofluorescence staining was used to detect LC3-II expression. Autophagosome formation was observed by electron microscopy. LIG significantly decreased apoptosis, increased Bcl-2, Beclin 1 and LC3-II expression, decreased Bax expression, increased LC3-II immunoreactivity and the number of autophagosomes, and activated the LKB1-AMPK-mTOR signaling pathway in PC12 cells exposed to OGD/R. The addition of the autophagy inhibitor 3-methyladenine or dorsomorphin before OGD/R attenuated the activation of the LKB1-AMPK-mTOR signaling pathway in cells treated with LIG. Taken together, our findings show that LIG promotes autophagy and protects PC12 cells from apoptosis induced by OGD/R via the LKB1-AMPK-mTOR signaling pathway.  相似文献   

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Objective To determine whether sulforaphane (SFN) protects neurons against injury caused by oxygen-glucose deprivation/reoxygenation (OGD/R) and, if so, to investigate the possible mechanisms. Methods Primary cultures of neurons were prepared from the cerebral cortex of 1-day-old Sprague-Dawley rats. On days 5-6 in vitro, the neurons were exposed to OGD for 1 h, followed by reoxygenation for 24 h. Cells were treated with 0, 0.1, 0.2, 0.5, 1, 2.5, or 5 μmol/L SFN, with or without 10 μmol/L LY294002, a PI3K-specific inhibitor, during OGD/R (a total of 25 h). After 24-h reoxygenation, MTT was used to assess viability and injury was assessed by Hoechst 33258/propidium iodide (PI) staining; immunofluorescence staining and Western blot were performed to detect molecular events associated with apoptosis. Results The MTT assay showed that 1 μmol/L SFN significantly increased viability, and Hoechst 33258/PI staining showed that the numbers of injured neurons were reduced significantly in the SFN group. Furthermore, immunofluorescence staining and Western blot showed that SFN increased Bcl-2 and decreased cleaved caspase-3 levels. Moreover, LY294002 inhibited the phosphorylated-Akt expression evoked by SFN, decreased Bcl-2 expression and increased cleaved caspase-3 expression. Conclusion SFN protects neurons against injury from OGD/R and this effect may be partly associated with an anti-apoptosis pathway.  相似文献   

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We recently reported that a phosphodiesterase-III inhibitor, cilostazol, prevented the hemorrhagic transformation induced by focal cerebral ischemia in mice treated with tissue plasminogen activator (tPA) and that it reversed tPA-induced cell damage by protecting the neurovascular unit, particularly endothelial cells. However, the mechanisms of cilostazol action are still not clearly defined. The adheren junction (AJ) protein, VE-cadherin, is a known mediator of endothelial barrier sealing and maintenance. Therefore, we tested whether cilostazol might promote expression of adhesion molecules in endothelial cells, thereby preventing deterioration of endothelial barrier functions. Human brain microvascular endothelial cells were exposed to 6-h oxygen-glucose deprivation (OGD). We compared cilostazol with aspirin treatments and examined 2 representative AJ proteins: VE-cadherin and platelet endothelial cell adhesion molecule-1 (PECAM-1). A protein kinase A (PKA) inhibitor, LY294002 (a PI3-K inhibitor), db-cAMP, and RP-cAMPS were used to assess the roles of cAMP, PKA, and PI3-K signaling, respectively, in cilostazol-induced responses. Cilostazol and db-cAMP prevented OGD-stress injury in endothelial cells by promoting VE-cadherin expression, but not PECAM-1. Aspirin did not prevent cell damage. P13-K inhibition by LY294002 had no influence on the effects of cilostazol, but inhibition of cAMP/PKA with PKA inhibitor and Rp-cAMPS suppressed cilostazol-induced inhibition of cell damage and promotion of VE-cadherin expression. In contrast, OGD stress had no detectable effects on VEGF, VEGF receptor, or angiopoietin-1 levels. Cilostazol promotes VE-cadherin expression through cAMP/PKA-dependent pathways in brain endothelial cells; thus, cilostazol effects on adhesion molecule signaling may provide protection against OGD stress in endothelial cells.  相似文献   

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《Neurological research》2013,35(10):1022-1028
Abstract

Penehyclidine hydrochloride (PHC) is an anticholinergic agent, with only high degree of selectivity for M1 and M3 receptor subtypes. In this study, we investigated whether PHC could play a protective effect on hippocampal slice against oxygen and glucose deprivation (OGD), as well as related to the change of amino acid neurotransmitters release. Penehyclidine hydrochloride 2, 10, and 50 μM doses were adopted in the lactate dehydrogenase (LDH) leakage assay and triphenyl tetrazolium chloride (TTC) staining. The spontaneous miniature excitatory postsynaptic currents (mEPSCs) and amino acid neurotransmitters were detected by electrophysiology method and high-performance liquid chromatography (HPLC), respectively. Our study showed that PHC can lessen the LDH leakage ratio and tissue injury values according to TTC staining. Penehyclidine hydrochloride decreased the content of aspartate acid (Asp) and glutamate (Glu), and elevated the content of glycine (Gly) and gamma-aminobutyric acid (GABA). Ischemia increased the amplitude and frequency of the mEPSCs, but PHC obviously decreased the frequency and amplitude of mEPSCs. Thus, the study reveals the fact that PHC protects hippocampus slice against OGD injury by decreasing excitatory amino acids release and increasing inhibitory amino acids release.  相似文献   

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In our in vitro model, rasagiline a selective irreversible monoamine oxidase-B (MAO-B) inhibitor, protected nerve growth factor (NGF)-differentiated PC12 cells from cell death under oxygen and glucose deprivation (OGD). The severity of the OGD insult, as expressed by cell death, was time-dependent. Exposure of the cells to OGD for 3 hr followed by 18 hr of reoxygenation caused about 30-40% cell death. Under these conditions, the neuroprotective effect of rasagiline was dose-dependent: rasagiline reducing OGD-induced cell death by 68% and 80% at 100 nM and 1 microM, respectively. The neuroprotective effect of rasagiline was also observed when added after the OGD insult (55% reduction in cell death). Under rasagiline treatment, there was a lesser decrease in ATP content in cultures exposed to OGD compared with that in untreated cultures. OGD followed by reoxygenation resulted in a several fold increase in PGE(2) release into the extracellular medium. Rasagiline (100 nM-1 microM) markedly inhibited OGD-induced PGE(2) release. Clorgyline, a monoamine oxidase-A (MAO-A) inhibitor, did not protect NGF-differentiated PC12 cells against OGD-induced cell death. As NGF-differentiated PC12 cells contain exclusively MAO type A, these data suggest that the neuroprotective effect of rasagiline under OGD conditions is independent of MAO inhibition.  相似文献   

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目的 探讨环状RNA TLK1(CircRNA TLK1,CircTLK1)对氧糖剥夺/复氧(Oxygen glucose deprivation/Reoxygenation,OGD/R)诱导的神经元HT22损伤的影响以及对微小RNA(microRNA,miR)-424-5p/F-box蛋白3(F-box protein 3,FBXO3)的调控作用。方法 将HT22细胞分为对照组、OGD/R组、sh-NC组、沉默环状RNA TLK1(Silencing circular RNA tlk1,sh-circTLK1)组、sh-circTLK1+抑制剂NC组、sh-circTLK1+miR-424-5p抑制剂组、sh-circTLK1+miR-424-5p抑制剂+sh NC组、sh-circTLK1+miR-424-5p抑制剂+sh FBXO3组,除对照组外其余各组细胞均行OGD/R操作,细胞计数试剂盒8(Cell counting Kit 8,CCK-8)法测定HT22细胞活力; 脂连蛋白V-异硫氰酸荧光素(Adiponectin V-fluorescein isothiocyanate,Annexin V-FITC)细胞凋亡试剂盒测定HT22细胞凋亡; 测定HT22细胞乳酸脱氢酶(Lactate dehydrogenase,LDH)漏出率; 实时荧光定量聚合酶链反应(Real time fluorescent quantitative polymerase chain reaction,RT-qRCR)法测定HT22细胞miR-424-5p,FBXO3 mRNA水平; 蛋白免疫印记法(Western Blot)检测B淋巴细胞瘤-2关联基因X(B lymphoma-2 gene association X,Bax)、活化半胱天冬酶-3(Cleaved caspase-3)、FBXO3水平; 双荧光素酶测定CircTLK1与miR-424-5p以及miR-424-5p与FBXO3靶向关系,并使用RNA下拉实验验证CircTLK1与miR-424-5p关系。结果 与对照组比较,OGD/R组miR-424-5p,HT22细胞活力降低(P<0.05),circTLK1,FBXO3 mRNA水平,HT22细胞凋亡率、Bax,Cleaved caspase-3水平、LDH漏出率升高(P<0.05); 与OGD/R组比较,sh-circTLK1组HT22细胞活力增加(P<0.05),HT22细胞凋亡率、Bax,Cleaved caspase-3水平,LDH漏出率降低(P<0.05); 与sh-circTLK1组比较,sh-circTLK1+miR-424-5p抑制剂组细胞活力降低(P<0.05),HT22细胞凋亡率、Bax,Cleaved caspase-3水平、LDH漏出率升高(P<0.05); 与sh-circTLK1+miR-424-5p抑制剂组比较,sh-circTLK1+miR-424-5p抑制剂+sh FBXO3组细胞活力升高(P<0.05),HT22细胞凋亡率、Bax,Cleaved caspase-3水平、LDH漏出率降低(P<0.05); CircTLK1与miR-424-5p以及miR-424-5p与FBXO3均存在靶向关系。结论 CircTLK1沉默可能通过调控miR-424-5p/FBXO3对OGD/R诱导的HT22细胞损伤来发挥保护作用。  相似文献   

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Apelin-13 has protective effects on many neurological diseases, including cerebral ischemia. Here, we aimed to test Apelin-13's effects on ischemic neurovascular unit (NVU) injuries and investigate whether the effects were dependent on vascular endothelial growth factor (VEGF). We detected the expression of VEGF and its receptors (VEGFRs) induced by Apelin-13 injection at 1 d, 3 d, 7 d and 14 d after middle cerebral artery occlusion (MCAO). Meanwhile, we examined the effects of Apelin-13 on NVU in both in vivo and in vitro experiments as well as whether the effects were VEGF dependent by using VEGF antibody. We also assessed the related signal transduction pathways via multiple inhibitors. We demonstrated Apelin-13 highly increased VEGF and VEGFR-2 expression, not VEGFR-1. Importantly, Apelin-13 led to neurological functions improvement by associating with promotion of angiogenesis as well as reduction of neuronal death and astrocyte activation, which was markedly blocked by VEGF antibody. In cell cultures, Apelin-13 protected neurons, astrocytes and endothelial cells against oxygen-glucose deprivation (OGD) injuries. Moreover, the effect of Apelin-13 to up-regulate VEGF was suppressed by extracellular signal-regulated kinase (ERK) inhibitor U0126 and phosphatidylinositol 3′-kinase (PI3K) inhibitor LY294002. Our data suggest protective effects of Apelin-13 on ischemic NVU injuries are highly associated with the increase of VEGF binding to VEGFR-2, possibly acting through activation of ERK and PI3K/Akt pathways.  相似文献   

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Cyclooxygenase-2 (COX-2) enzyme increases abnormally during excitotoxicity and cerebral ischemia and promotes neurotoxicity. Although COX-2 inhibitors could be beneficial, they have significant side effects. We and others have shown that the EP1 receptor is important in mediating PGE2 toxicity. Here, we tested the hypothesis that pretreatment with a highly selective EP1 receptor antagonist, ONO-8713, would improve stroke outcome and that post-treatment would attenuate NMDA-induced acute excitotoxicity and protect organotypic brain slices from oxygen-glucose deprivation (OGD)-induced toxicity. Male C57BL/6 mice were injected intracerebroventricularly with ONO-8713 before being subjected to 90-min middle cerebral artery occlusion (MCAO) and 96-h reperfusion. Significant reduction in infarct size was observed in groups given 0.1 (25.9 ± 4.7%) and 1.0 nmol (27.7 ± 2.8%) ONO-8713 as compared with the vehicle-treated control group. To determine the effects of ONO-8713 post-treatment on NMDA-induced excitotoxicity, mice were given a unilateral intrastriatal NMD A injection followed by one intraperitoneal injection of 10 µg/kg ONO-8713, 1 and 6 h later. Significant attenuation of brain damage (26.6 ± 4.9%) was observed at 48 h in the ONO-8713-treated group. Finally, brain slice cultures were protected (25.5 ± 2.9%) by the addition of ONO-8713 to the medium after OGD. These findings support the notion that the EP1 receptor propagates neurotoxicity and that selective blockade could be considered as a potential preventive and/or therapeutic tool against isch-emic/hypoxic neurological conditions.  相似文献   

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Recent data show that geldanamycin can protect the brain against stroke in vivo, and this may be due to induction of heat shock proteins. Our previous results show that heat shock protein 70 expression by retroviral transfection protects astrocytes from necrotic injury by combined oxygen-glucose deprivation, an in vitro model of ischemia. This study tested the ability of geldanamycin to protect astrocytes from either necrotic or apoptotic injury induced by oxygen-glucose deprivation. Astrocytes were pre-treated with 0.1 microgram ml-1 geldanamycin in the medium 4, 8, or 16 h before as well as during oxygen-glucose deprivation. Increased protein levels of heat shock protein 70 were observed after 8 h pre-treatment with geldanamycin and increased further at 16 h pre-treatment, as detected by immunoblotting. Geldanamycin pre-treatment protected mature astrocytes from necrotic cell death and young astrocytes from apoptotic death. Geldanamycin protection of astrocytes against in vitro ischemia is likely due to upregulation of heat shock protein 70.  相似文献   

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BackgroundCerebral ischemia/reperfusion (I/R) injury after ischemic stroke is usually accompanied with the activation of inflammasome which seriously impairs neurological function. MiR-139 has been reported to be associated with inflammatory regulation in multiple diseases. However, its effect and mechanism on inflammation regulation after cerebral I/R injury are still poorly understood.MethodsAn in vitro model of cerebral I/R injury was constructed with oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. TargetScan bioinformatics analysis and dual luciferase reporter assay were utilized to confirm the targeted relationship between miR-139 and c-Jun. Cell pyroptosis was verified by flow cytometry and Caspase-1 Detection Kit. qRT-PCR assay was performed to detect the expression levels of miR-139, c-Jun, NLRP3 and ASC. Western blotting was applied to measure the protein levels of c-Jun and pyroptosis-related markers NLRP3, ASC, caspase-1, GSDMDNterm. The ELISA assay was applied to measure the release of IL-1β, IL-18 and LDH.ResultsMiR-139 was significantly downregulated whereas c-Jun was obviously upregulated after OGD/R treatment. TargetScan analysis predicted that c-Jun was a potential target of miR-139, which was verified by the dual-luciferase reporter assay. Also, overexpression of miR-139 repressed c-Jun expression. Furthermore, miR-139 inhibited OGD/R-induced cell pyroptosis and the upregulation of NLRP3, caspase-1, ASC, GSDMDNterm, and the release of IL-1β, IL-18 and LDH, while miR-139 inhibition exerted the opposite effects. However, overexpression of c-Jun aggravated OGD/R-induced nerve injury and partly abolished the neuroprotective effect of miR-139.ConclusionUpregulation of miR-139 exerted neuroprotection against OGD/R-induced nerve injury by negatively regulating c-Jun/NLRP3 inflammasome signaling. This study offered insights for providing potential therapeutic targets for treating cerebral I/R injury.  相似文献   

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目的观察过氧化物酶体增殖物激活受体γ(PPAR-γ)激动剂15d-PGJ_2对神经元氧糖剥夺/复氧(OGD/R)损伤的影响,并探讨其可能的作用机制。方法采用原代培养的小鼠胎鼠大脑皮质神经元,建立OGD/R损伤模型。将培养的神经元细胞进行分组,Western blot检测各组神经元内LC3-1、LC3-Ⅱ、Bcl-2、Beclin1、AMPK、m TOR及p70S6K等蛋白的表达;MTT法检测细胞活性,乳酸脱氢酶(LDH)漏出率测定细胞毒性。结果 OGD/R损伤6 h、12 h及24 h后神经元LC3-Ⅱ、Beclin 1表达明显增高,而p62表达持续下降,神经元的生存率明显下降,LDH漏出率增加。15d-PGJ_2可显著降低LC3-Ⅱ和Beclin 1表达水平,改善神经元的生存率及降低LDH的漏出率。OGD/R后Bcl-2的蛋白表达水平均明显减少,而Beclin 1表达则显着增加。15d-PGJ_2预处理显著增加OGD/R 24 h的Bcl-2表达量。利用Bcl-2 siRNA或scRNA转染神经元细胞发现,Bcl-2 siRNA可消除15d-PGJ_2对OGD/R后各时间点的抑制效应。结论 15d-PGJ_2能够有效地对神经元OGD/R损伤起到保护作用,其机制可能是通过上调Bcl-2的表达进而抑制自噬的发生实现的。  相似文献   

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