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1.
Zhang J  Tan Z  Tran ND 《Brain research》2000,877(2):134-140
Cerebral endothelial cell (CEC) death from ischemia may exacerbate brain injury by altering microvascular integrity, but little is known concerning the pattern of CEC death and disruption of tight junction between two CECs to ischemia. To address these questions, CECs were isolated from bovine, cultured, and placed in glucose-free medium containing sodium cyanide. Trypan blue staining shown that sodium cyanide resulted in a dose-dependent insult of CECs (10-80 mM). CEC injury increased progressively with the duration of 20 mM cyanide exposure, becoming significant (71%) after 12 h. The mode of cell death induced by cyanide is clearly apoptosis in CECs, as shown by Hoechst 33,342 staining and transmission electron microscope, i.e. cyanide induced condensation and margination of chromatin, nuclear fragmentation and shrinkage of cell body and condensed apoptotic bodies in CECs. Most importantly, we found that the tight junction between two CECs was disrupted 12 h after chemical-ischemia, i.e. when CECs underwent apoptosis, the tight junctional complexes became thinner and rough; the cleft of tight junction between two CECs became blurred and more wider, and membranes of tight junction were course and irregular; and the adherens junctions were damaged. These results indicate that chemical hypoxia-ischemia induces apoptotic cell death in CECs and alters the microvascular integrity by disrupting tight junction complexes, and suggest that CEC apoptotic death and disruption of tight junction may exacerbate ischemic insults to brain. Thus, prevention of CEC apoptotic death may contribute to improvements of ischemic insults.  相似文献   

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Although the underlying mechanisms of isoflurane-induced cognitive impairments remain largely to be determined, neuronal inflammation and apoptosis are thought to be major contributors. Resveratrol is a naturally available herbal compound for the treatment of inflammatory and neurodegenerative diseases. We therefore aimed to investigate the effects of resveratrol on the isoflurane-induced cognitive impairments and the associated hippocampal inflammation responses and neuronal apoptosis in the aged mice. Fifteen-month-old male C57BL/6 mice received 2 h of 1.5 % isoflurane or oxygen exposure 24 h after the intraperitoneal injection of resveratrol or saline daily for 7 consecutive days. Here, we showed that the isoflurane anesthesia decreased the freezing time to context significantly at 48 h after the isoflurane exposure in the fear conditioning test. The hippocampal levels of IL-1β, TNF-α, NLRP3, cleaved caspase-3, and Bax increased significantly while the hippocampal levels of IkBα and Bcl-2 decreased significantly at 6 and/or 48 h after the isoflurane anesthesia. All these effects induced by isoflurane were attenuated by resveratrol pretreatment. However, the isoflurane anesthesia had no significant effect on the hippocampal Sirt1. In conclusion, our results suggest that resveratrol attenuates the hippocampus-dependent cognitive impairment induced by isoflurane anesthesia through its anti-inflammation and anti-apoptosis effects in aged mice.  相似文献   

4.
Recent findings underscore that some natural compounds are responsible for specific biochemical effects, i.e., the activation of redox‐sensitive intracellular pathways and modulation of different stress proteins, such as heat shock proteins and sirtuins. Resveratrol, a natural polyphenol widely present in plants, has been shown to display various beneficial effects, including neuroprotection, in several pathological conditions. In the present study, by using differentiated SH‐SY5Y neuroblastoma cells, we investigated the potential protective effects of resveratrol against homocysteine‐induced neurotoxicity. We observed that homocysteine (100 µM) decreased cell viability while at the same time significantly increasing intracellular reactive oxygen species and DNA fragmentation. Cell pretreatment with resveratrol concentrations ranging from 1 to 5 µM elicited protective effects through the reduction of oxidative stress and genotoxic damage. In addition, we observed that resveratrol produced significant changes in the expression of both Hsp70 and sirtuin 1 (SIRT1). After homocysteine treatment in the presence of resveratrol, SIRT1 protein was found abundantly not only in the cytosol but also in the nucleus, as demonstrated by confocal laser scanning microscopy. The results of this study suggest that resveratrol is a potential protective agent against homocysteine‐induced neurotoxicity and that beneficial effects are accompanied by changes in cell stress response. Taken together, these features contribute to our knowledge of underlying mechanisms involved in resveratrol‐induced cell survival. © 2014 Wiley Periodicals, Inc.  相似文献   

5.
Resveratrol mimics ischemic preconditioning in the brain.   总被引:4,自引:0,他引:4  
Recent studies in a variety of species including mammals showed that resveratrol (trans-3, 5, 4'-trihydroxystibene) treatment and caloric restriction increased silent information regulator 2/sirtuin 1 activity, which mediated increase in life span/cell survival. Resveratrol is a naturally occurring phytoalexin and a well-documented cardioprotective agent. Similarly, ischemic preconditioning (IPC) has been shown to be both cardio- and cerebroprotective against subsequent ischemic insults. A major emphasis in this field is to understand the molecular mechanisms that mediate this phenomenon. The goal of this study was to define whether resveratrol can emulate IPC neuroprotection against cerebral ischemia. Employing an in vitro model of cerebral ischemia, the organotypic hippocampal slice culture, we report that resveratrol pretreatment mimics IPC via the SIRT1 pathway. Blockade of SIRT1 activation by sirtinol after IPC or resveratrol pretreatment abolished their neuroprotection. A better understanding of the mechanisms by which resveratrol induces ischemic tolerance in a prophylactic manner may provide a novel therapy against stroke or neurosurgical procedures.  相似文献   

6.
Death induced by oxidized low density lipoproteins (oxLDL) to embryonic CNS neuronal and neuroblastoma cells was investigated. Cell damage and viability were evaluated by LDH leakage and the MTT method, respectively. Dose- and time-dependent degeneration of neurons occurred after oxLDL (1–100 μg/ml) treatment but was absent after native low density lipoproteins (LDL). This degeneration was mediated, in part, by apoptosis because increased TUNEL and Hoechst dye-positive staining was observed. These effects occurred in the absence of microglia. However, DNA degradation was not detected. The cytotoxicity was attenuated by pre-treatment with antioxidants. These results suggest that oxidation by oxLDL may be important in neurocytotoxicity in the brain.  相似文献   

7.
In several cell systems, protein kinase B (Akt1) can promote cell growth and development, but the "antiapoptotic" pathways of this kinase that may offer protection against cellular inflammatory demise have not been defined. Given that early cellular membrane phosphatidylserine exposure is a critical component of apoptosis, we investigated the role of Akt1 during neuronal apoptotic injury. By employing differentiated SH-SY5Y neuronal cells that overexpress a constitutively active form of Akt1 (myristoylated Akt1), free radical-induced cell injury was assessed through trypan blue dye exclusion, DNA fragmentation, membrane phosphatidylserine exposure, protein kinase B phosphorylation, cysteine protease activity, and mitochondrial membrane potential. Membrane phosphatidylserine exposure was both necessary and sufficient for microglial activation, insofar as cotreatment with an antiphosphatidylserine receptor-neutralizing antibody could prevent microglial activity following neuronal loss of membrane asymmetry. Furthermore, expression of myristoylated Akt1 not only prevented cell injury through the prevention of membrane phosphatidylserine exposure and genomic DNA fragmentation but also inhibited microglial activation and proliferation that required the inhibition of caspase 9-, caspase 3-, and caspase 1-like activities linked to cytochrome c release. Interestingly, Akt1 modulation of membrane phosphatidylserine exposure was primarily through caspase 1 activity. Removal of Akt1 activity abolished neuronal protection, suggesting that Akt1 functions as a critical pathway for the maintenance of cellular integrity and the prevention of phagocytic cellular removal during neurodegenerative insults.  相似文献   

8.
BackgroundCerebral ischemia is as a result of insufficient cerebral blood flow for cerebral metabolic functions. Resveratrol is a natural phytoalexin that can be extracted from grape''s skin and had potent role in treating the cerebral ischemia. Apoptosis, a genetically programmed cellular event which occurs after ischemia and leads to biochemical and morphological changes in cells. There are some useful markers for apoptosis like Bcl-2, bax, and p53. The last reports, researchers verify the apoptosis with early markers like Annexin V.MethodsWe preferred in this experimental study a model of global cerebral infarction which was induced by bilateral common carotid artery occlusion method. Rats were randomly divided into 4 groups : sham, ischemia-reperfusion (I/R), I/R plus 20 mg/kg resveratrol and I/R plus 40 mg/kg resveratrol. Statistical analysis was performed using Sigmastat 3.5 ve IBM SPSS Statistics 20. We considered a result significant when p<0.001.ResultsAfter administration of resveratrol, Bcl-2 and Annexin levels were significantly increased (p<0.001). Depending on the dose of resveratrol, Bcl2 levels increased, p53 levels decreased but Annexin V did not effected. P53 levels were significantly increased in ishemia group, so apoptosis is higher compared to other groups.ConclusionIn the acute period, Annexin V levels misleading us because the apoptotic cell counts could not reach a certain level. Therefore we should support our results with bcl-2 and p53.  相似文献   

9.
Resveratrol interacts with the complex III of the respiratory chain, is a radical scavenger and also suppressor of radical formation in the mitochondria. It reduces the intracellular calcium levels in pre- and postsynaptic neurons and also may inhibit the pro-apoptotic factors in glutamate overflow that occurs, e.g. in excitotoxicity. In cell cultures, glutamate overflow leads to formation of free radicals and results in apoptosis. This increase of radical concentration is enhanced by influx of cations like iron or copper ions into the cell. In present study, the beneficial action of resveratrol was investigated in glutamate-affected dissociated cultures of mice mesencephalic primary cultures. On the 10th day in vitro, 5 mM of glutamate was administered for 15 min and the cultures were further maintained in medium containing 0, 0.01, 0.1 or 1 μM of resveratrol. Resveratrol reduced glutamate-induced damages. The number of dopaminergic neurons was increased and their morphology ameliorated when resveratrol followed glutamate treatment. A significant reduction of glutamate-induced radical formation in cultures treated with resveratrol corresponded with a considerable high antioxidative potential of this stilbene determined using the DPPH assay. In addition, ICP-OES was set up to measure the tissues’ copper and iron contents in organotypic cortical cultures of glutamate treated (0 or 30 μM) slices and those in which resveratrol (0, 0.01, 0.1 or 1 μM) was co-administered. Levels of copper were dose-dependently increased, and also the concentration of iron was higher in resveratrol-treated organotypic cultures. The hypothesis that resveratrol has beneficial actions against glutamate damages was verified.  相似文献   

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Micro-RNA(miRNA) are well studied small noncoding RNA, which plays a diverse role in the regulation of vital elements in cell survival and apoptosis. However, the functional significance of miRNAs after the pathogenesis of ischemic stroke remains unclear. The present study is designed to investigate the regulatory role of miR-149-5p on Sirtuin-1/p53 axis during ischemic-reperfusion-induced injury. Middle cerebral artery occlusion (MCAO) was performed by nylon monofilament for 60 min. Resveratrol was administered via intraperitoneal (IP) route, 30 min before the MCAO. Our study demonstrated that the miR-149-5p levels were markedly decreased at 24 h after ischemic-reperfusion (I/R) injury. Further, we observed decreased p53 protein expression and increased miR-149-5p activity on sirtuin1 (Sirt1) activation with resveratrol after 24 h following MCAO. Moreover, immunohistochemistry studies found that resveratrol treatment significantly decreased the immunoreactivity of p53 and caspase-3 on activation of Sirt1/miR149-5p axis. In conclusion, our findings suggest that miR-149-5p could play a regulatory role in neuronal cell death via Sirt1/p53 axis, which offers a new target for novel therapeutic interventions during acute ischemic stroke.  相似文献   

12.
Resveratrol, a naturally occurring polyphenol has received significant attention as a potent anti-inflammatory agent. Inflammatory bowel disease (IBD) is a chronic intestinal inflammation caused by hyperactivated effector immune cells that produce proinflammatory cytokines. Myeloid derived suppressor cells (MDSCs) are a heterogeneous population characterized by the co-expression of CD11b+ and Gr-1+ and have long been known for their immunosuppressive function. We report that resveratrol effectively attenuated overall clinical scores as well as various pathological markers of colitis in IL-10−/− mice by down regulating Th1 responses. Resveratrol lessened the colitis-associated decrease in body weight and increased levels of serum amyloid A (SAA), CXCL10 and colon TNF-α, IL-6, RANTES, IL-12 and IL-1β concentrations. After resveratrol treatment, the percentage of CXCR3 expressing T cells was decreased in the spleen, mesenteric lymph nodes (MLN), and intestinal lamina propria (LP). However, the percentage and absolute numbers of CD11b+ and Gr-1+cells in the lamina propria (LP) and spleen were increased after resveratrol treatment as compared with the vehicle treatment. Co-culture of resveratrol-induced CD11b+ Gr-1+ cells with T cells, attenuated T cell proliferation, and most importantly reduced IFN-γ and GM-CSF production by LP derived T cells from vehicle treated IL-10−/− mice with chronic colitis. The current study suggests that administration of resveratrol into IL-10−/− mice induces immunosuppressive CD11b+ Gr-1+ MDSCs in the colon, which correlates with reversal of established chronic colitis, and down regulation of mucosal and systemic CXCR3+ expressing effector T cells as well as inflammatory cytokines in the colon. The induction of immunosuppressive CD11b+ Gr-1+ cells by resveratrol during colitis is unique, and suggests an as-yet-unidentified mode of anti-inflammatory action of this plant polyphenol.  相似文献   

13.
Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.  相似文献   

14.
Resveratrol, a naturally occurring polyphenol, exhibits antioxidant, antiaging, and anticancer activity. Resveratrol has also been shown to inhibit tumor initiation, promotion, and progression in a variety of cell culture systems. Earlier, we showed that paraquat, a bipyridyl herbicide, triggers endoplasmic reticulum stress, cell dysfunction, and dopaminergic cell death. Due to its antioxidant activity, we assessed the ability of resveratrol to rescue cells from the toxic effects of paraquat. While resveratrol did not have any protective effect at low concentrations, it triggered endoplasmic reticulum (ER) stress-induced cell death at higher concentrations (50–250 μM). The present study was carried out to determine the mechanism by which resveratrol triggers ER stress and cell death in dopaminergic N27 cells. Our studies demonstrate that resveratrol triggers ER stress and cell dysfunction, caspase activation, p23 cleavage and inhibition of proteasomal activity in dopaminergic N27 cells. While over expression of uncleavable p23 was associated with decreased cell death, downregulation of p23 protein expression by siRNA resulted in enhancement of ER stress-induced cell death triggered by resveratrol indicating a protective role for the small co-chaperone p23 in dopaminergic cell death.  相似文献   

15.
Cellular and molecular pathways underlying hypoxic neurotoxicity and cell death are multifaceted and complex. Although many potentially neuroprotective agents have been investigated, the protection conferred is often inadequate, resulting in their insufficient clinical utility. In light of the above, we investigated the therapeutic potential and mechanism of action of acetyl-L-carnitine (ALCAR) in protecting hippocampal neurons from hypoxia-induced neurotoxicity and cellular death. Results showed decreased viability of hippocampal cells when exposed to hypoxia (3% O(2)) for 48 hr along with concomitant membrane depolarization, adenosine triphosphate depletion, DNA fragmentation, accentuated free radical production, and lactate dehydrogenase activity. Pretreatment with ALCAR significantly attenuated hypoxia-induced cytotoxicity in a dose-dependent manner and improved cellular glutathione levels and cytochrome c oxidase activity compared with normoxic controls. Supplementation of ALCAR also prevented apoptosis by down-regulating caspase-3 levels, cytochrome c release, and p-Bcl-2 expression. A decrease in nerve growth factor (NGF) was observed in hypoxic stress despite increased phosphorylation of ERK1/2 (extracellular signal-related kinase) and its downstream effector, Elk-1. Supplementation of ALCAR, on the other hand, up-regulated NGF and tyrosine kinase A expression along with concomitant increase in ERK1/2 phosphorylation, thus enhancing cell survival. ALCAR therefore provides neuroprotection by stabilizing mitochondrial membrane, restoring the cholinergic transmission, and more importantly, it stimulates NGF receptors, thus triggering cell survival pathway via ERK phosphorylation. Therefore, ALCAR may be useful as an effective therapeutic agent for hypoxic stress and associated neurodegenerative diseases.  相似文献   

16.
Peripheral neuropathies are widespread disorders induced by autoimmune diseases, drug or toxin exposure, infections, metabolic insults or trauma. Nerve damage may cause muscle weakness, altered functionalities and sensitivity, and a chronic pain syndrome characterized by allodynia and hyperalgesia. Pathophysiological mechanisms related to neuropathic disease are associated with mitochondrial dysfunctions that lead to the activation of the apoptotic cascade. In a model of peripheral neuropathy, obtained by the loose ligation of the rat sciatic nerve (CCI), we describe a nerve apoptotic state that encompasses the release of cytochrome C in the cytosol, the activation of caspase 3, and the fragmentation of the genome. Animal treatment with acetyl-L-carnitine (ALCAR), but not with L-carnitine (L-Carn) or Gabapentin, prevents apoptosis induction. ALCAR reduces cytosolic cytochrome C and caspase 3 active fragments expression in a significant manner with respect to saline treatment. Accordingly, ALCAR treatment impairs caspase 3 protease activity, as demonstrated by reduced levels of cleaved PARP. Finally, ALCAR decreases the number of piknotic nuclei. This protection correlates with the induction of X-linked inhibitor apoptosis protein (XIAP). Taken together these results show that CCI is a valuable model to investigate neuropathies-related apoptosis phenomena and that ALCAR is able to prevent regulated cell death in the damaged sciatic nerve.  相似文献   

17.
We have demonstrated in the SH-SY5Y human neuroblastoma cell line that the antineoplastic drug paclitaxel induces apoptosis associated with the phosphorylation of c-raf and Bcl-2, thus causing Bcl-2 inactivation. In addition, we have observed the cleavage of caspase 7 and PARP, and the involvement of JNK/SAPK cascade.
In this study, we investigated the possible anti-apoptotic effect of resveratrol on paclitaxel-induced apoptosis. Resveratrol is a natural antioxidant occurring in grapes and wine that as been shown to have anticancer and anti-inflammatory effects. Studies on the effect(s) of resveratrol on nervous cells are very few and limited to testing its ability in preventing oxidative stress in rat pheocromocytoma PC12 cells. However, the biological and pharmacological properties of resveratrol suggest that this natural compound might act on neuronal cells with a mode of action that is different from the antioxidant ones. To confirm this hypothesis, we studied the possible antagonist effect(s) of resveratrol on paclitaxel-induced apoptosis pathways.
Our results indicate that the simultaneous treatment of 50M resveratrol and 1M paclitaxel induces a significant reduction of the percentage of apoptotic cells in comparison with 1M paclitaxel alone. Furthermore, we have demonstrated that resveratrol treatment determines a significant reduction of the phosphorylation of c-raf and Bcl-2 and a partial reduction of cleavage of caspase 7 and PARP. Finally, we observed an evident reduction of activation of JNK/SAPK in the presence of resveratrol. On the contrary, resveratrol does not affect the tubulin polymerization induced by paclitaxel.
In conclusion, our results suggest that resveratrol is able to partially antagonize a nonoxidative stress apoptotic stimulus by influencing the typical signal pathways involved in apoptosis.  相似文献   

18.
白黎芦醇对GH3细胞增殖和PRL合成的影响   总被引:2,自引:0,他引:2  
目的 探讨白黎芦醇对垂体腺瘤GH3细胞增殖和泌乳素合成的影响,及其对雌激素的拮抗作用。方法 在无血清无酚红的培养条件下,白黎芦醇单独或与雌二醇联合作用于GH3细胞,用MTT法测定细胞增殖,用免疫荧光法、RT-PCR和Western印迹法测定泌乳素的表达情况。结果 白黎芦醇对GH3细胞增殖具有刺激和抑制双相作用,呈时间一剂量依赖性。并且白黎芦醇使GH3细胞中PRL阳性细胞比例下降。同时,白黎芦醇抑制泌乳素的合成。白黎芦醇对雌二醇诱发的细胞增殖和泌乳素合成均有拮抗作用.但对泌乳素合成的拮抗作用较强,而雌二醇刺激细胞增殖作用较其诱发泌乳素合成作用强。结论 白黎芦醇对GH3细胞增殖和泌乳素合成均有抑制作用,从两方面发挥着抗肿瘤作用。  相似文献   

19.
目的 观察线粒体功能失调在缺血再灌后神经元凋亡中的作用。方法(1)采用体外培养神经母细胞瘤细胞株N2a细胞,体外模拟缺血再灌注(缺氧90min,然后再灌不同时间);(2)采用琼脂糖凝胶电泳检测细胞凋亡情况;(3)MTT法、细胞色素c释放和跨膜压的改变判断线粒体的功能;(4)caspase-3活性测定采用水解其可见光底物。结果(1)N2a细胞缺血再灌12h即出现明显DNA片段化,24h更明显;(2)线粒体酶活性降低.跨膜电位在缺氧再灌1h先短暂下降再升高然后又明显降低。细胞色素c缺氧再灌3h开始下降,6h达到高峰.持续到24h;(3)caspase-3活性在缺氧再灌10h升高,24h达到高峰,线粒体通透性转换孔形成抑制剂CsA只能抑制部分caspasc-3的活性和DNA片段化改变;而caspase-8抑制剂虽不能完全抑制caspase-3的活性但能完全抑制DNA的片段化。结论N2a凋亡尚存在有caspase-3依赖性和非依赖性两条途径线粒体功能失调在缺氧再灌引起的N2a细胞凋亡过程中可能起到凋亡早期的启动和随后的信号放大作用。  相似文献   

20.
The main pathophysiology of cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Resveratrol has been reported to be one of the most potent chemopreventive agents that can inhibit cellular processes associated with ischemic stroke. Matrix metalloproteinases(MMPs) has been considered as a potential drug target for the treatment of cerebral ischemia. To explore this, we tried to investigate the interaction of resveratrol with MMPs through molecular docking studies. At 30 minutes before and 2 hours after cerebral ischemia/reperfusion induced by occlusion of the middle cerebral artery, 40 mg/kg resveratrol was intraperitoneally administered. After resveratrol administration, neurological function and brain edema were significantly alleviated, cerebral infarct volume was significantly reduced, and nitrite and malondialdehyde levels in the cortical and striatal regions were significantly decreased. The molecular docking study of resveratrol and MMPs revealed that resveratrol occupied the active site of MMP-2 and MMP-9. The binding energy of the complexes was –37.848672 k J/mol and –36.6345 k J/mol for MMP-2 and MMP-9, respectively. In case of MMP-2, Leu 164, Ala 165 and Thr 227 were engaged in H-Bonding with resveratrol and in case of MMP-9, H-bonding was found with Glu 402, Ala 417 and Arg 424 residues. These findings collectively reveal that resveratrol exhibits neuroprotective effects on cerebral ischemia through inhibiting MMP-2 and MMP-9 activity.  相似文献   

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