Oxidative stress is one of the pathological mechanisms of Alzheimer’s disease (AD), and ferroptosis has been determined to be involved in neurodegenerative diseases such as AD. Senegenin (Sen) prevents oxidative damage in nerve cells via a mechanism that may be highly related to ferroptosis. However, the mechanism of ferroptosis pathway involvement in AD is unclear. In this study, we established a model of PC12 cytotoxic injury induced by Aβ25–35, and we detected the level of oxidative damage, MMP, and ferroptosis-related protein expression. The results showed that, compared with control group, the level of ROS increased, GPX activities decreased, and MDA levels increased in Aβ25–35 group. Aβ25–35 could induce mitochondrial depolarization in PC12 cells and Fer-1 could not reverse this damage. WB revealed that Aβ25–35 group had increased ACSL4 and PEBP1 proteins, and decreased GPX4 protein. After adding Sen in the model, the level of oxidative damage was reduced, and mitochondrial depolarization was reversed compared with Aβ25–35 group. WB suggested that the expression of ACSL4 and PEBP1 proteins decreased, and the expression of GPX4 protein increased by Sen treatment. In conclusion, we found that Sen exhibits strong neuroprotective activity against Aβ25–35 induced oxidative damage and lipid metabolic associated with ferroptosis. Inhibiting nerve cell ferroptosis might facilitate the future development of strategies to AD.

RhoGDIα is an inhibitor of RhoGDP dissociation that involves in Aβ metabolism and NFTs production in Alzheimer's disease (AD) by regulating of RhoGTP enzyme activity. Our previous research revealed that RhoGDIα, as the target of Polygala saponin (Sen), might alleviate apoptosis of the nerve cells caused by hypoxia/reoxygenation (H/R). To further clarify the role of RhoGDIα in the generation of NFTs, we explored the relationship between RhoGDIα and Tau. We found out that RhoGDIα and Tau can bind with each other and interact by using coimmunoprecipitation (Co-IP) and GST pulldown methods in vitro. This RhoGDIα-Tau partnership was further verified by using immunofluorescence colocalization and fluorescence resonance energy transfer (FRET) approaches in PC12 cells. Using the RNA interference (RNAi) technique, we found that the RhoGDIα may be involved in an upstream signaling pathway for Tau. Subsequently, in Aβ25-35- and H/R-induced PC12 cells, forced expression of RhoGDIα via cDNA plasmid transfection was found to reduce the hyperphosphorylation of Tau, augment the expression of bcl-2 protein, and inhibit the expression of Bax protein (reducing the Bax/bcl-2 ratio) and the activity of caspase-3. In mouse AD and VaD models, forced expression of RhoGDIα via injection of a viral vector (pAAV-EGFP-RhoGDIα) into the lateral ventricle of the brain alleviated the pathological symptoms of AD and VaD. Finally, GST pulldown confirmed that the binding sites on RhoGDIα for Tau were located in the range of the ΔC33 fragment (aa 1–33). These results indicate that RhoGDIα is involved in the phosphorylation of Tau and apoptosis in AD and VaD. Overexpression of RhoGDIα can inhibit the generation of NFTs and delay the progress of these two types of dementia.

目的:探讨远志皂苷元(Sen)对缺氧/复氧(H/R)损伤大鼠肾上腺嗜铬细胞瘤PC12细胞模型中铁死亡的影响及可能的机制.方法:培养高分化PC12细胞,构建H/R损伤细胞模型和erastin诱导铁死亡细胞模型.采用MTT法检测细胞活力;显微镜下观察细胞形态变化,微管相关蛋白2(MAP-2)荧光染色观察神经元突触的变化;检测细胞上清液乳酸脱氢酶(LDH)及细胞内亚铁离子(Fe2+)、总谷胱甘肽(GSH)和谷胱甘肽过氧化物酶(GSH-Px)水平;荧光探针DCFH-DA标记检测活性氧簇(ROS)水平;JC-1染色观察线粒体膜电位(ΔΨm)的变化;Western blot检测铁死亡相关蛋白(ACSL4、GPX4和SLC7A11)的表达.结果:确定H/R造模时间为缺氧12 h,复氧2 h,细胞活力降低约50％(P＜0.05);铁死亡造模条件为10 μmol/L铁死亡诱导剂erastin作用14 h,细胞活力降低约50％(P＜0.05).不同浓度Sen或铁死亡抑制剂ferrostatin-1(Fer-1)作用14 h后,细胞活力无显著变化(P＞0.05).Sen或Fer-1干预后,与模型组相比,细胞活力显著升高(P＜0.05).与对照组相比,H/R和erastin组细胞显著变小变圆,突触变短(P＜0.05),细胞上清液LDH水平及细胞内Fe2+和ROS水平显著升高(P＜0.05),细胞内GSH水平、GSH-Px活性和ΔΨm水平显著降低(P＜0.05).Sen或Fer-1干预后,与模型组相比,细胞形态接近正常,突触显著变长(P＜0.05),细胞上清液LDH水平及细胞内Fe2+和ROS水平显著降低(P＜0.05),细胞内GSH水平、GSH-Px活性和ΔΨm水平显著升高(P＜0.05).与对照组相比,H/R组和erastin组ACSL4蛋白表达显著升高,GPX4和SLC7A11蛋白表达显著降低(P＜0.05);Sen或Fer-1干预后,与模型组相比,ACSL4蛋白表达显著降低,GPX4和SLC7A11蛋白表达显著升高(P＜0.05).结论:H/R损伤PC12细胞模型中存在铁死亡,且Sen能抑制铁死亡,发挥保护细胞的作用,其机制可能与Sen提高细胞清除氧自由基能力、降低细胞内Fe2+水平和上调GPX4蛋白表达等有关.

目的:分析肾间质纤维化(RIF)早期的蛋白质组表达变化情况,为探讨干预RIF的新靶点奠定基础.方法:(1)48只雄性Wistar大鼠,随机分为正常对照(control)组(6只)、假手术(sham)组(6只)和单侧输尿梗阻(UUO)模型组(36只).UUO组行右侧输尿管结扎,并分别于术后第3、7、11、14、21和28天各处死6只,取肾脏标本行HE染色和Masson染色,光镜下观察病理变化;control组不作任何处理,sham组开腹后只分离右输尿管但不结扎,两组均于第28天取肾脏标本作病理观察;(2)取UUO术后第7天大鼠梗阻侧和健侧肾组织的蛋白质提取液行双向凝胶电泳,两侧对照找出差异蛋白质,选取部分差异蛋白点进行质谱鉴定;(3)Western blot检测UUO大鼠肾脏组织膜联蛋白A5(annexin A5)表达的动态变化.结果:(1)UUO各组梗阻肾脏逐渐出现肾小管扩张、炎症细胞浸润、肾小管上皮细胞萎缩、间质胶原纤维沉积等变化,其中,肾梗阻后第7天开始出现间质纤维化;(2)与健侧肾比较,UUO术后第7天的梗阻侧肾出现≥1.5倍的差异蛋白质166个,其中上调81个,下调85个,质谱成功鉴定出19种差异蛋白质;(3)Western blot显示,各时段UUO组大鼠梗阻侧肾组织中annexin A5表达均明显高于sham组(P<0.05),其中以梗阻第3天组的表达量最高,随后逐渐下降,但仍高于sham组.结论:(1)RIF早期存在大量表达差异的蛋白质;(2)RIF的annexin A5表达显著增加,可能与某些病理变化存在密切关系.

Abstract The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to global public health and there is currently no effective antiviral therapy. It has been suggested that chloroquine (CQ) and hydroxychloroquine (HCQ), which were primarily employed as prophylaxis and treatment for malaria, could be used to treat COVID-19. CQ and HCQ may be potential inhibitors of SARS-CoV-2 entry into host cells, which are mediated via the angiotensin-converting enzyme 2 (ACE2), and may also inhibit subsequent intracellular processes which lead to COVID-19, including damage to the cardiovascular (CV) system. However, paradoxically, CQ and HCQ have also been reported to cause damage to the CV system. In this review, we provide a critical examination of the published evidence. CQ and HCQ could potentially be useful drugs in the treatment of COVID-19 and other ACE2 involved virus infections, but the antiviral effects of CQ and HCQ need to be tested in more well-designed clinical randomized studies and their actions on the CV system need to be further elucidated. However, even if it were to turn out that CQ and HCQ are not useful drugs in practice, further studies of their mechanism of action could be helpful in improving our understanding of COVID-19 pathology.

Myocardial dysfunction accompanied by severe sepsis could significantly increase the mortality rate of septic patients. This study investigated the effects and the potential mechanisms of sevoflurane preconditioning on septic myocardial dysfunction, which was induced by lipopolysaccharide (LPS; from Escherichia coli O55:B5; 18 mg/kg) in mice. Results indicated that 1 hour after the administration, LPS induced a significant increase in cell-surface Toll-like receptor 4 (TLR4), cytoplasmic IKKα protein expression, and nuclear translocation of nuclear factor kappa-B (NF-κB) protein (P < 0.05), which was attenuated by preconditioning with sevoflurane. Two hours after the administration, inhalation of sevoflurane significantly reduced the serum levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-10 (P < 0.05). Twelve hours after administration, LPS caused pathological damage to the heart and elevated the serum levels of lactate dehydrogenase (LDH) and creatine kinase-MB (P < 0.05). Echocardiography indicated that sevoflurane preconditioning significantly improved systolic and diastolic function. The inhalation of sevoflurane inhibited increases in myeloperoxidase (MPO), macrophage inflammatory protein-2 (MIP-2), TNF-α, and IL-1β levels (P < 0.05) induced by endotoxemia, whereas IL-6 release was facilitated. Sevoflurane attenuated the myocardial levels of nitric oxide (P < 0.05) without an apparent influence on malondialdehyde (MDA) or superoxide dismutase (P > 0.05). In conclusion, our study indicates that exposure to 2% sevoflurane before LPS challenge is protective against myocardial dysfunction. Sevoflurane preconditioning may attenuate neutrophil infiltration and the release of inflammatory mediators during endotoxemia.

PYNOD, a nod-like receptors (NLR)-like protein, was indicated to inhibit NF-κB activation, caspase-1-mediated interleukin (IL)-1β release and cell apoptosis in a dose-dependent manner. Exogenous addition of recombinant PYNOD to mixed glial cultures may suppress caspase-1 activation and IL-1β secretion induced by Aβ. However, to the best of our knowledge, there no study has focused on the immunoregulatory effects of PYNOD specifically in microglia. The present study aimed to explore the roles of PYNOD involved in the lipopolysaccharides (LPS)-induced microglial inflammation and consequent neurotoxicity. Murine microglial BV-2 cells were transfected with pEGFP-C2-PYNOD (0-5.0 µg/ml) for 24 h and incubated with or without LPS (1 µg/ml) for a further 24 h. Cell viability was determined using MTT assay and the secretion of nitric oxide (NO), IL-1β and caspase-1 was measured using the Griess method or ELISA. Protein expression levels of NF-κB p65 and inducible nitric oxide synthase (iNOS) were detected by immunofluorescent staining and/or western blot analysis. Co-culture of BV-2 cells with human neuroblastoma cell line SK-N-SH was performed in Transwell plates and the cell viability and apoptosis (using flow cytometry) of SK-N-SH cells were determined. Results indicated that PYNOD overexpression inhibited NO secretion and iNOS protein expression induced by LPS in BV-2 cells, with no detectable cytotoxicity. PYNOD overexpression also reduced the secretion of IL-1β and caspase-1 from BV-2 cells upon LPS stimulation. These effects were dose-dependent. Additionally, PYNOD overexpression prevented LPS-induced nuclear translocation of NF-κB p65 in BV-2 cells. The growth-inhibitory and apoptosis-promoting effects of BV-2 cells towards SK-N-SH cells were alleviated as a result of PYNOD overexpression. In conclusion, PYNOD may mitigate microglial inflammation and consequent neurotoxicity.

Cardiomyopathy is a common complication associated with increased mortality in sepsis, but lacks specific therapy. Here, using genetic and pharmacological approaches, we explored the therapeutic effect of α2A-adrenergic receptor (AR) blockade on septic cardiomyopathy. CLP-induced septic rats were treated with BRL44408 (α2A-AR antagonist), prazosin (α1-AR antagonist) and/or reserpine. CLP-induced cardiomyopathy, indicated by reduced dP/dt and increased cardiac troponin I phosphorylation, was attenuated by BRL44408, this was associated with reduced cardiac TNF-α and endothelial VCAM-1 expression, cardiomyocyte apoptosis and related signal molecule phosphorylation. BRL44408 increased cardiac norepinephrine (NE) concentration in CLP rats. Pretreatment with reserpine that exhausts cardiac NE without affecting the circulating NE concentration or with prazosin partially abolished the cardioprotection of BRL44408 and reversed its inhibitory effects on myocardial TNF-α, apoptosis and related signal molecule phosphorylation, but not on VCAM-1 expression in septic rats. These effects of BRL44408 were confirmed by α2A-AR gene deletion in septic mice. Furthermore, α2-AR agonist not only enhanced LPS-induced TNF-α and VCAM-1 expression in cardiac endothelial cells that express α2A-AR, but also enhanced LPS-induced cardiac dysfunction in isolated rat hearts. Our data indicate that α2A-AR blockade attenuates septic cardiomyopathy by promoting cardiac NE release that activates myocardial α1-AR and suppressing cardiac endothelial activation.

AIM:To screen and verify the effective ingredient of traditional Chines medicine (TCM) Q0409 in improving learning and memory ability of mice.METHODS:The mouse learning and memory impairment model was induced by intraperitoneal injection of scopolamine.The mice in each group were given the corresponding drug by gavage at the same time for 14 d in succession.Morris water maze test was used to measure the learning and memory ability of the mice, and then the hippocampal tissue homogenate was taken to determine the activity of acetylcholinesterase (AChE).The animals were divided into 8 groups according to L8(27) orthogonal table.The variance analysis and factorial analysis were used to analyze the pharmacological effects of seven kinds of single herbal in TCM Q0409 and determine the screening ingredients.The animals were divided into 6 groups according to the results of the preliminary screening results, and further testing and validation of TCM Q0409 screening ingredients were performed to get the final simplified ingredients.RESULTS:Three medicinal herbs of Polygalae, Panax ginseng and Acori graminei rhizome were screened by the orthogonal results of Morris water maze test and the activity of AChE in mouse hippocampal tissues.The simplified ingredients of TCM Q0409 were obtained through the variance results of Morris water maze test and the activity of AChE in mouse hippocampal tissues.CONCLUSION:Polygala and ginseng were eventually determined as simplified ingredients of TCM Q0409 and it was verified that they improve the learning and memory ability of the mice with learning and memory impairment.

Activator of 90kDa heat shock protein ATPase homolog 1 (AHSA1) is a chaperone of heat shock 90kDa (HSP90) and stimulates ATPase activity of HSP90. The function of AHSA1 in osteosarcoma (OS) has not been reported yet. A previous study showed AHSA1 was overexpressed in OS cells. In this study, we investigated the role of AHSA1 in OS cells by silencing AHSA1. We report that silencing AHSA1 inhibited cell growth, migration, and invasion, and increased apoptosis of MG-63 and Saos2 cells. We also found that silencing AHSA1 decreased the ATPase activity of HSP90 in OS cells. In addition, silencing AHSA1 increased the levels of negative regulators of Wnt/β-catenin signalling pathway, Axin-2 and GSK3β, and decreased the levels of two key members of Wnt/β-catenin signalling pathway, namely, Wnt-5a and β-catenin. In conclusion, silencing AHSA1 regulates cell growth, apoptosis, migration, and invasion by regulating Wnt/β-catenin signalling pathway and their negative regulators.

AIM: To observe the effects of berberine (Ber) on enterocyte apoptosis in septic mice and its pos-sible mechanism.METHODS: Male C57BL/6 mice (8 ~10 weeks old) were randomly divided into sham group, cecal ligation and puncture (CLP) group, CLP +Ber group and sham +Ber group.The mice in CLP group underwent CLP ope-ration, and the mice in sham groups suffered a similar operation except the ligation and puncture.After the sham or CLP operation, the mice were administered intragastrically with distilled water or berberine (50 mg/kg) within 2 h.After 20 h, the mice were killed with excess pentobarbital sodium and the ileum tissues were removed.The histological changes of the intestine were observed and the enterocyte apoptosis was examined by determining the protein level of cleaved caspase-3. Furthermore, mitochondrial Bax, cytoplasm cytochrome C (Cyt C) and the total proteins of Bcl-2, Fas, FasL and Fas-as-sociated protein with death domain (FADD) were examined by Western blot.The mRNA expression of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) was measured by real-time PCR.RESULTS: The extensive ileum injuries, including remarkably increased leukocytes and necrosis of intestinal villus were observed 20 h after CLP.In CLP group, the protein levels of cleaved caspase-3, cytoplasm Cyt C, as well as Fas, FasL were significantly increased, but the Bcl-2 level was decreased.Bax translocation into mitochondria was promoted.However, FADD was not changed significantly.The mRNA expression of TH and DBH was also increased sharply in CLP group.On the contrary, treatment with berberine made a considerable alleviating alteration in the ileum of the septic mice.CONCLUSION: Treatment with berberine pro-vides protective effects on intestinal injury in septic mice by reducing enterocyte apoptosis, and its possible mechanism may be involved in the inhibition of the endogenous and exogenous apoptosis pathways.

Neural stem cells (NSCs) transplanted is one of the hottest research to treat Alzheimer’s disease (AD), but cholinergic neurons from stem cells were also susceptible to cell death which Heat shock protein 70 (HSP70) was affirmed to reverse. Related to cognitive impairment, cholinergic nervous cells should be investigated and ginsenoside Rg1 (G-Rg1) was considered to increase them. We chose tert-butyl hydroperoxide (t-BHP) damage model to study in vitro. Functional properties of our recombination plasmid pEGFP-C2-HSP70 were affirmed by SH-SY5Y cells. To opposite the transitory appearance of HSP70, NSCs used as the vectors of HSP70 gene overexpressed HSP70 for at least 7 days in vitro. After transfection for 3 days, G-Rg1 pretreatment for 4 hours, and coculture for 3 days, the expression of acetylcholinesterase (ChAT), synaptophysin, and the ratio of NeuN and GFAP were assessed by western blot; Morphological properties were detected by 3D reconstruction and immunofluorescence. ChAT was markedly improved in the groups contained G-Rg1. In coculture system, the ratio of neurons/astrocytes and the filaments of neurons were increased; apoptosis cells were decreased, compared to monotherapy (P<0.05). In conclusion, we demonstrated that, as a safe cotreatment affirmed in vitro, overexpression of HSP70 in NSCs plus G-Rg1 promoted nervous cells regeneration from chronic oxidative damage.

Microglial activation plays an important role in neurodegenerative diseases associated with oxidative stress. tert-Butyl hydroperoxide (t-BHP), an analog of hydroperoxide, mimics the oxidative damage to microglial cells. It has been reported that ginsenoside Rg1 (G-Rg1), an active ingredient of Panax ginseng, has anti-stress and anti-inflammatory properties. The present study aims to investigate the ability of G-Rg1 to decrease the t-BHP-mediated cell damage of BV2 microglial cells. We performed flow cytometry assays to facilitate the detection of reactive oxygen species as well as Western blotting analyses and immunofluorescence assays using specific antibodies, such as antibodies against phospho-mitogen-activated protein kinases (p-MAPKs), phospho-nuclear factor-κB (p-NF-κB), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), Caspase-3, autophagy marker light chain 3 (LC3), and Becline-1. We found that treatment with 50μm G-Rg1 protected microglial cells against oxidative damage induced by 10μm t-BHP.

目的：观察叶黄素对视网膜神经节细胞系（ RGC－5）的保护作用，并对其机制进行初步探讨。方法：将RGC－5细胞随机分为：对照组、t－BHP组、t－BHP和叶黄素共同作用组、叶黄素组，培养24 h，MTT检测细胞活力；Annexin V－FITC／PI 双染流式细胞仪检测细胞凋亡率；免疫细胞化学法检测caspase－3蛋白的活化情况；Western blot检测Bcl－2／Bax、cleaved caspase－3、JNK和c－Jun蛋白的变化。结果：MTT法和流式细胞检测结果显示叶黄素可对抗t－BHP诱导的RGC－5细胞凋亡；免疫荧光结果显示叶黄素可减少t－BHP诱导的caspase－3的活化；Western blot结果显示t－BHP处理后RGC－5细胞抗凋亡蛋白Bcl－2表达下调，促凋亡蛋白Bax和cleaved caspase－3表达上调，JNK和c－Jun蛋白的磷酸化水平增加，叶黄素能部分逆转上述结果。结论：叶黄素能够对抗t－BHP诱导的RGC－5细胞凋亡而显示其保护作用，其机制是抑制Bax／Bcl－2表达及caspase－3蛋白活化，并降低JNK和c－Jun蛋白的磷酸化。

目的：观察阻断α2A－肾上腺素能受体（ AR）对脓毒症性心功能障碍的影响。方法：利用雄性大鼠和α2A－AR基因敲除小鼠，通过盲肠结扎穿孔（CLP）建立脓毒症模型，观察心功能和相关分子变化。结果：α2A－AR阻断剂BRL可改善CLP大鼠生存和心功能，明显降低CLP大鼠心肌TNF－α含量，抑制心肌中性粒细胞浸润，降低心肌MPO的表达，并减少p38、JNK、IκBα的磷酸化与心肌细胞凋亡。 BRL进一步升高CLP大鼠心肌NE的含量。利用利血平耗竭心肌NE可部分消除BRL对CLP大鼠心功能的保护作用，同时消除BRL对CLP大鼠心肌p38、IκBα与cTnI磷酸化以及TNF－α的抑制作用，但不影响BRL对CLP大鼠心肌MPO的抑制作用；事先注射1－AR阻断剂可模拟利血平的作用，部分消除BRL对CLP大鼠心功能的保护作用。敲除α2A－AR基因可进一步验证上述结果。结论：阻断α2A－AR一方面通过促进心脏交感神经释放NE，激活α1－AR，由此减少心肌TNF－α、抑制细胞凋亡和cTnI磷酸化，增强心肌收缩力；另一方面通过阻断NE与心脏血管内皮α2A－AR结合，减轻心肌中性粒细胞浸润和心肌损伤。

AIM:To observe the effect of B-HT933, a selective α2-adrenoceptor agonist, on lipopolysaccha-ride ( LPS )-induced TNF-αproduction in neonatal rat cardiomyocytes and to explore the underlying mechanisms . METHODS:The neonatal rat cardiomyocytes were cultured .The localization of α2A-adrenoceptor in the cardiomyocytes was examined by immunofluorescence staining .The cardiomyocytes were exposed to LPS or/and B-HT933 for different time.The level of TNF-αin the supernatants and the mRNA expression of TNF-αwere detected by ELISA and real-time PCR, respectively.In addition, LPS-associated signal molecules in the cardiomyocytes were also examined by Western blotting.RESULTS: Immunofluorescence staining showed that α2A-adrenoceptors were localized in the cardiomyocytes . LPS stimulated TNF-αproduction in the cardiomyocytes in a dose and time-dependent manner .B-HT933 pretreatment sig-nificantly inhibited the expression of TNF-αat mRNA and protein levels in LPS-treated cardiomyocytes .Furthermore, LPS exposure induced IκBαand p38 phosphorylation in cardiomyocytes and only IκBαphosphorylation was prevented by B-HT933 treatment.CONCLUSION:α2A-adrenoceptors are present in neonatal rat cardiomyocytes and its agonist B -HT933 inhibits LPS-induced TNF-αproduction in cardiomyocytes via suppressing IκBαphosphorylation .

目的：初步探讨缺氧／复氧（ hypoxia／reoxygenation，H／R）诱导PC12细胞凋亡模型中tau蛋白及其磷酸化水平、凋亡相关蛋白Bax、Bcl－2的表达情况。方法：类神经元PC12细胞体外培养并传至第三代，进行相应处理，实验分组为正常对照组（ control组）、模型组（ H／R组）。 Annexin V－PI双染流式细胞术分别检测各组凋亡率以确定模型是否成功；造模成功后，使用RIPA裂解液提取蛋白；Western blotting技术检测各组tau蛋白及其磷酸化、Bax和Bcl－2的表达变化。结果：与control组相比，H／R组细胞凋亡率显著升高（ P＜0．05），提示模型构建成功；Westem blotting结果显示，与control组相比，H／R组中tau蛋白表达显著减少（P＜0．05），且tau蛋白Ser202位点的磷酸化水平显著升高（P＜0．05），Bax／Bcl－2显著升高（P＜0．05）。结论：Tau蛋白可能参与了缺氧／复氧诱导的神经细胞凋亡，其机制有待深入研究。

目的:构建重组pEGFP-HSP70质粒并观察其在神经干细胞中的表达.方法:采用RT-PCR方法从SD胎鼠肝组织中获取总RNA,扩增出热休克蛋白70(HSP70)基因的全序列cDNA,并克隆到含有增强型绿色荧光蛋白(EGFP)基因的真核表达载体pEGFP-C2上,经EcoR Ⅰ、BamH Ⅰ酶切及测序分析对重组质粒pEGFP-HSP70进行鉴定.采用Nucleofector转染技术将重组质粒pEGFP-HSP70转染至胎鼠神经干细胞中.结果:(1)胎鼠HSP70cDNA序列被正确地克隆到真核表达载体pEGFP-C2中,成功构建重组大鼠pEGFP-HSP70质粒.荧光强度检测空质粒转染组(pEGFP-C2组)、pEGFP-HSP70组与对照组相比显著升高(P＜0.01);pEGFP-HSP70组内24h的荧光强度与7 d(P ＜0.05)、14 d(P ＜0.05)和21 d(P＜0.01)相比降低明显.(2)转染后HSP70的表达在1d(P＜0.05)、7 d(P＜0.01)和14 d(P ＜0.01)与对照组相比均明显升高.结论:神经干细胞可直接作为基因靶细胞,能有效地表达重组质粒pEGFP-HSP70,且HSP70在神经干细胞中的表达与转染时间密切相关.