Src、Fyn激酶对脑缺血/再灌注大鼠海马NMDA受体NR2A亚基磷酸化水平的影响

目的观察脑缺血再灌注后海马Src家族酪氨酸蛋白激酶（Src family of protein tyrosine kinase,SrcPTKs）成员Src、Fyn激酶对NMDA受体（N-methyl-D-aspartate receptors,NMDAR,NR）NR2A亚基磷酸化水平的影响。方法采用Pulsinelli-Brierley四动脉阻断（four-vessel occlusion,4-VO）大鼠全脑缺血模型,缺血前连续3天脑室注射Src、Fyn反义寡核苷酸（antisense oligode oxynucletides,AS-ODNs）及错义寡核苷酸组（missenseoligodeoxynucletides,MS ODNs）后缺血15 min,用免疫沉淀和免疫印迹法检测NR2A亚基酪氨酸磷酸化水平的变化。结果Fyn反义寡核苷酸使脑缺血再灌注海马NR2A亚基磷酸化水平下降,而Src反义寡核苷酸对脑缺血/再灌注海马NR2A亚基磷酸化水平影响更加明显。结论脑缺血/再灌注过程中NMDA受体NR2A亚基的磷酸化主要是由Src激酶介导的。     

NMDA受体亚单位2A在大鼠海马缺血/再灌注损伤中的作用

目的观察NMDA受体亚单位2A(NR2A)特异性反义寡核苷酸阻断大鼠海马CA1区NR2A表达后在缺血性脑损伤中产生的变化,以揭示NR2A在缺血性脑损伤中的作用。方法健康雄性SD大鼠随机分为正常对照组、假手术组和缺血/再灌注组。分别经反义寡核苷酸、正义寡核苷酸、生理盐水对照和空白对照预处理后,以四血管阻断法建立短暂性前脑缺血(15min)/再灌注(24h和48h)动物模型。在确定的时间内进行灌注固定、取材、石蜡包埋和组织切片(片厚8μm),然后行原位杂交染色、TUNEL染色和焦油紫染色。结果缺血/再灌注早期(24h)大鼠海马CA1区NR2AmRNA的表达水平显著增高(P<0.05)。经反义寡核苷酸预处理后,大鼠海马CA1区NR2AmRNA的表达水平显著降低(P<0.05);同时TUNEL染色显示,在缺血/再灌注24h和48h凋亡阳性细胞的数量也明显降低(P<0.05)。结论短暂性前脑缺血后,NR2AmRNA的表达水平与细胞凋亡在时间上和空间上具有一致性,提示NR2A参与了脑缺血/再灌注诱导的细胞凋亡过程。     

曲美他嗪对大鼠局灶性脑缺血再灌注Bcl-2 mRNA、Caspase-3 mRNA表达的影响

目的观察曲美他嗪（TMZ）对大鼠局灶性脑缺血后神经细胞Caspase-3 mRNA、Bcl-2 mRNA表达的影响。方法成年健康Wistar大鼠45只,随机分为假手术对照组（n=5）、脑缺血再灌注组（n=20）、TMZ预处理组（n=20）。应用线栓法建立大脑中动脉闭塞再灌注模型。采用原位杂交方法检测脑组织Caspase-3 mRNA、Bcl-2m RNA表达的变化。结果Bcl-2 mRNA在缺血再灌注3h表达增强（P〈0.05）,6h显著增强（P〈0.01）,24h减弱（P〈0.05）,48h消失（P〉0.05）。TMZ组的Bcl-2 mRNA表达量多于缺血再灌注组,差异有统计学意义（P〈0.05）。Caspase-3 mRNA在再灌注3h表达增强（P〈0.05）,6h显著增强（P〈0.01）,24h更加明显（P〈0.01）,48h减弱（P〈0.05）。TMZ组的Caspase-3 mRNA表达量显著少于缺血再灌注组,差异有统计学意义（P〈0.05）。结论TMZ可能通过诱导Bcl-2的表达和抑制Caspase-3的生成而发挥抗凋亡作用。     

电针对脑缺血再灌注模型大鼠海马IL-6受体mRNA表达的影响

目的观察IL-6受体在脑缺血再灌注脑损伤中表达的变化,及电针对其表达的影响。方法雄性SD大鼠随机分为假手术组、模型组、电针组,每组又各分为6h和24h观察组,各组每个时相各5只。采用改良Longa线栓法复制大脑中动脉局灶性脑缺血再灌注模型;电针组治疗取百会(DU20)及大椎(DU14)两穴,疏密波刺激30min。应用qPCR法测定受损侧海马IL-6RαmRNA及gp130mRNA的表达。结果 IL-6RαmRNA的表达随着时间的延长下降:在脑缺血再灌注6h,模型组IL-6RαmRNA表达最低,与假手术组相比有显著性差异(P0.01),与电针组相比有显著性差异(P0.05);在24h时,模型组仍最低,与假手术组相比有显著性差异(P0.01),与电针组相比无显著性差异,假手术组与电针组无显著性差异。IL-6信号转导子gp130mRNA表达随着时间的延长上升:在脑缺血再灌注6h,3组gp130mRNA表达无显著性差异;在24h时,假手术组表达无明显变化,模型组、电针组表达有所上升,电针组表达最高,与模型组相比有显著性差异(P0.05),与假手术组相比有显著性差异(P0.01),模型组与假手术组相比无显著性差异。结论电针早期介入可以上调缺血再灌注脑组织的IL-6RαmRNA、gp130mRNA表达,这可能是电针发挥脑保护作用机制的一个途径。     

NR2B反义寡核苷酸对大鼠海马CA1区NR2B蛋白质表达的影响

目的 观察NMDA受体2B亚单位（NR2B）反义寡核苷酸（ANR2B）对海马CA1区NR2B蛋白质表达的影响，筛选有效的反义寡核苷酸，为探讨针对NR2B的新药物提供形态学基础。方法 设计、筛选、合成ANR2B。正常SD大鼠，海马CA1区立体定位注射ANR2B，灌注取脑，连续冰冻切片，ABC免疫组织化学方法染色，光镜下观察NR2B蛋白质的表达变化。结果 注射ANR2B后，注射区及其周围NR2B免疫组织化学染色强度明显下降。仅有少量锥体细胞和颗粒细胞散在分布；而在注射NR2B正义寡核苷酸（SNR2B）、生理盐水及生理盐水插针不注射的海马切片上，海马CA1区的染色特征与注射ANR2B者有明显差别，其作用区锥体细胞、颗粒细胞及顶树突的NR2B免疫组织化学染色强度无明显变化。结论 ANR2B能够降低NR2B蛋白质在正常大鼠海马CA1区的基础性高表达。     

Anti-miR-155反义寡核苷酸对A549细胞Weel表达的影响

目的观察anti-miR-155反义寡核苷酸（AMOs）对A549细胞Weel表达的影响。方法采用特异性an—ti-miR-155反义寡核苷酸抑制A549细胞内成熟miR一155的活性,realtimequantitiveRT—PCR测定WeelmRNA表达量,Westernblot测定Weel蛋白和Phospho—cdc2（Tyrl5）蛋白的表达量。结果lOOnmol／L浓度的AMOs处理的A549细胞中Weel1TIRNA表达量与对照组A549细胞中WeelITIRNA表达量相比无显著性差异（P〉0．05）;与对照组相比,100nmol／L浓度的AMOs处理的A549细胞Weel蛋白和Phospho—cdc2（Tyrl5）蛋白的表达量显著增加（P〈O．05）。结论采用AMOs抑制A549细胞内高水平表达miR-155活性后,可显著增强Weel蛋白的表达。     

二氮嗪对深低温脑缺血再灌注大鼠脑组织NR1表达的影响

目的 探讨二氮嗪对深低温缺血再灌注大鼠的脑保护作用及其机制。方法 采用双侧颈总动脉阻断法制作深低温缺血再灌注大鼠模型,将306只SD大鼠随机分成3组：假手术组、二氮嗪组和模型组。分别在缺血1 h后再灌注2、6、12 h及1、2、3、7 d断头取脑,对脑组织行含水量检测,并采用免疫组织化学技术检测脑组织NR1表达情况。结果 假手术组脑组织含水量明显低于二氮嗪组和模型组,二氮嗪组低于模型组,模型组和二氮嗪组脑组织含水量在12 h开始升高、1d达高峰、3 d基本恢复正常,模型组和二氮嗪组NR1均在2 h开始升高、1 d达到高峰、7 d后基本达到正常水平,但二氮嗪组NR1表达水平在2、6、12 h及1、2 d明显低于模型组,且两组NR1表达水平均高于假手术组。结论 二氮嗪预处理对深低温缺血再灌注大鼠具有脑保护作用,其作用机制可能是通过下调脑组织NR1的表达来实现。     

NMDA受体亚单位NRl、NR2A、NR2B在生后大鼠海马的免疫组织化学表达

目的：观察大鼠海马NMDA受体亚单位NRl、NR2A、NR2B三种蛋白质的生后发育变化。方法：生后不同时段的SD大鼠各5只，作HE染色，NRl、NR2A、NR2B组化反应染色。结果：生后各时间点海马结构各区锥体细胞及颗粒细胞胞体中均有NR1、NR2A、NR2B的表达，NR2B还在锥体细胞的顶树突中有较强表达。NRl与NR2B在Pld和P4d，两者在CA3区的表达均高于CAl区，Plw后两者在CAl区的表达则高于CA3区，在P2w～P3w其表达至峰值。而NR2A在Pld、P4d时其在海马结构各区的表达较高，随发育时间表达下降，约在P4w降至谷底。整个发育过程中。NRl在海马各区的表达始终高于NR2A和NR2B的表达。提示生后早期中NRl、NR2A、NR2B的表达具有发育性时空差异。     

bcl-2反义寡核苷酸对膀胱癌BIU87细胞株的影响

目的:探讨bcl-2反义寡核苷酸对培养的膀胱癌BIU87细胞株的影响.方法:采用bcl-2基因第1外显子的反义寡核苷酸,以硫代磷酸修饰(PS-ASON),序列为5′-TCTCCCAGCGTGCGCCAT-3′,与膀胱癌细胞株BIU87共同孵育作为实验组.加入正义的bcl-2寡核苷酸,序列为5′-TACCGCGTGCGACCCTCT-3′(PS-SON)作为对照组,用流式细胞仪检测细胞凋亡和坏死率,电镜观察细胞形态变化.结果:与对照组相比,实验组的细胞坏死率明显上调,电镜下细胞形态呈坏死改变.结论:bcl-2的反义寡核苷酸引起膀胱癌细胞大量坏死,可能成为膀胱癌的治疗方法之一.     

七氟醚对缺氧无糖损伤大鼠海马 NR1亚基mRNA表达的影响

目的探讨七氟醚对缺氧无糖(oxygen and glucose deprivation，OGD)损伤大鼠海马NMDA受体NR。亚基mRNA表达的影响。方法大鼠海马脑片随机分为3组(n=3)，用RT—PCR方法检测对照组、缺氧组及七氟醚组大鼠离体海马脑片OGD损伤14min恢复氧糖供应孵育1、2、4h后NMDA受体NR1亚基mRNA的表达。结果恢复氧糖供应1、2h后NR1亚基mRNA的表达3组无明显差异，而缺氧组4h后NR1亚基mRNA的表达增高，七氟醚组恢复氧糖供应后4hNR1亚基mRNA的表达明显降低。结论七氟醚可通过下调OGD损伤引起的NR1亚基mRNA的表达发挥脑保护作用。     

NMDA受体亚单位NR1、NR2A和NR2B mRNA在成年大鼠海马的表达

目的 研究NMDA受体亚单位（NR1，NR2A和NR2B）mRNA在正常成年大鼠海马结构各区的表达及形态特点。方法 原位核酸分子杂交组织化学反应和图像处理与分析。结果 NR1，NR2A和NR2BmRNA在正常大鼠海马结构各区锥体细胞和颗粒细胞普遍表达，其中NR1mRNA的表达最强，NR2AmRNA的表达最弱，NR1mRNA在齿状回（DG）的表达水平明显强于CA1区和CA3区；NR2AmRNA在CA1区的表达水平则强于CA3区和DG；NR2BmRNA在海马各区的表达水平基本相同。结论 NR1，NR2A和NR2BmRNA在正常成年大鼠海马各区的表达模式不同，其中NR2AmRNA在海马CA1区以及NR1mRNA在DG高表达的分布特点可能与海马的学习，记忆等生理功能以及选择性易损现象有关。     

Inhibition of N-methyl-D-aspartate-activated current by bis(7)-tacrine in HEK-293 cells expressing NR1/NR2A or NR1/NR2B receptors

In normal rat forebrain, the NR1/NR2A and NR1/NR2B dimmers are the main constitutional forms of NMDA receptors. The present study was carried out to determine the functional properties of the heteromeric NMDA receptor subunits and their inhibition by bis(7)-tacrine (B7T). Rat NR1, NR2A and NR2B cDNAs were transfected into human embryonic kidney 293 cells (HEK-293).The inhibition of NMDA-activated currents by B7T was detected in HEK-293 cell expressing NR1/NR2A or NR1/NR2B receptors by using whole-cell patch-clamp techniques. The results showed that in HEK-293 cells expressing NR1/NR2A receptor, 1μmol/L B7T inhibited 30μmol/L NMDA- and 1000μmol/L NMDA-activated steady-state currents by 46% and 40%, respectively (P>0.05; n=5), suggesting that the inhibition of B7T on NR1/NR2A receptor doesn’t depend on NMDA concentration, which is consistent with a non-competitive mechanism of inhibition. But for the NR1/NR2B receptor, 1μmol/L B7T inhibited 30μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 61% and 13%, re-spectively (P<0.05; n=6), showing that B7T appears to be competitive with NMDA. In addition, simultaneous application of 1μmol/L B7T and 1000μmol/L NMDA produced a moderate inhibition of peak NMDA-activated current, followed by a gradual decline of the current to a steady state. However, the gradual onset of inhibition produced by B7T applied simultaneously with NMDA was eliminated when B7T was given 5s before NMDA. These results suggested that B7T inhibition of NMDA current mediated by NR1/NR2B receptor was slow onset, and it did not depend on the presence of the agonist. With holding potentials ranging from -50 to +50 mV, the B7T inhibition rate of NMDA currents didn’t change significantly, and neither did the reversal potential. We are led to conclude that the NR1/NR2B recombinant receptor can serve as a very useful model for studying the molecular mechanism of NMDA receptor inhibition by B7T.     

Activation and subcellular distribution of ERK1/2 following cerebral ischemia/reperfusion in rat hippocampus

Objective： To investigate the activation （phosphorylation） and subcellular localization of extracellular signal-regulated kinase （ERK1/2）, as well as the possible mechanism, following cerebral ischemia and ischemia/reperfusion in rat hippocampus. Methods： Transient brain ischemia was induced by the four-vessel occlusion method in Sprague-Dawley rats. Western blot analysis. Results： During cerebral ischemia without reperfusion ERK1/2 activation immediately increased with a peak at 5 min and then decreased in the cytosol fraction, which was paralleled by the increase of ERK1/2 activation in the nucleus fraction. During reperfusion, ERK1/2 was activated with peaks occurring at 10 min in the cytosol and at 30 min in the nucleus, respectively. Under those conditions, the protein expressions had no significant change. In order to clarify the possible mechanism of ERK1/2 activation, the rats were intraperitoneally administrated with N-methyl-D-aspartate （NMDA） receptor antagonist dextromethorphan （DM）, L-type voltage-gated Ca^2＋ channel （L-VGCC） antagonist nifedipine （ND） 20 rain before ischemia, finding that DM and ND markedly prevented ERK1/2 activation of nucleus fraction induced by reperfusion, not by ischemia. Conclusion： These results suggested that the nuclear translocation mainly occurred during ischemia, while ischemia-reperfusion induced ERK1/2 activation both in the cytosol and the nucleus. Two type calcium channels contributed, at least partially, to the activation of ERK1/2.     

Nimodipine Modulates Bcl-2 and Bax mRNA Expression after Cerebral Ischemia

In order to explore whether the member of Bcl-2 gene family, for example, Bcl-2 and Bax, are induced after cerebral ischemia, and whether expression of genes can be modulated by calcium-antagonist, the rat cerebral ischemic models were made by occluding left middle cerebral artery. The expression of Bcl-2 and Bax mRNA was measured by RT-PCR method. After middle cerebral artery occlusion (MCAO), the expression of both Bcl-2 and Bax mRNA were induced. Level of Bcl-2 mRNA increased steadily and level of Bax mRNA increased gradually at first, reached a peak after 24 h, then decreased slowly. After administration of nimodipine, Bcl-2 mRNA was up-regulated in the hippocampus 6 and 24h after ischemia, while Bax mRNA was down-regulated 6 and 24 h after ischemia. Focal cerebral ischemia can induce proto-oncogenes to express, which was associated with apoptosis. Calcium-antagonist can up-regulate Bcl-2 mRNA and down-regulate Bax mRNA.The increased ratio of Bcl-2 and Bax mRNA may contribute to the antiapoptic effect of nimodipine.The study indicates that pharmacological modulation of Bcl-2 family member expression could become a new stratehgy to manage neuronal damage.     

大鼠脑缺血再灌注后海马内Nemo样激酶的表达

目的:观察大鼠脑缺血再灌注后海马内Nemo样激酶(Nemo-like kinase,NLK)蛋白表达的变化及细胞定位?方法:60只成年雄性Sprague-Dawley大鼠随机分为假手术组和脑缺血再灌注组,其中脑缺血再灌注组依术后不同的检测时间点分为:1?4?8 h和1?3?7 d 6个亚组?采用中脑动脉闭塞法(middle cerebral artery occlusion,MCAO)建立脑缺血再灌注模型,用Western blot方法检测脑缺血再灌注后大鼠海马组织中NLK,活化的Caspase-3蛋白的变化趋势,用免疫组化和免疫荧光来检测NLK蛋白在脑组织中的细胞定位及可能发挥的生物学行为?结果:在脑缺血再灌注的海马组织中NLK蛋白随着脑缺血再灌注时间的延长而呈现先增高后降低,后再升高的趋势,其中缺血再灌注后8 h NLK蛋白表达达到高峰,与假手术组相比,差异有统计学意义(P﹤0.05)?活化的Caspase-3 的表达随着观察时间的延长递增,3 d达到峰值,与假手术组比较,差异有统计学意义(P﹤0.05),随后下降?NLK定位于脑组织中的神经元细胞尤其是海马CA1区的锥体神经元?结论:脑缺血再灌注后NLK蛋白的表达显著上调,提示NLK参与了成年大鼠脑缺血的发展?     

阿司匹林预处理对大鼠局灶性脑缺血/再灌注后IL-6、SOCS-3mRNA表达的影响

目的探讨阿司匹林（Aspirin,ASA）预处理后,对大鼠局灶性脑缺血/再灌注（cerebral ischemia/reperfu-sion,CI/RP）缺血脑组织保护作用的可能机制。方法将雄性健康SD大鼠95只随机分为假手术组、缺血对照组、小剂量ASA组（10mg/kg）、大剂量ASA组（150mg/kg）。采用改良线栓法制作大鼠CI/RP。术后分别在6、12、24、72h和7d时间点进行神经功能评分,白细胞介素6（IL-6）、细胞因子信号转导抑制因子（SOCS-3mRNA）含量检测,用术后24h的大鼠进行TTC染色计算脑梗死体积。结果阿司匹林预处理后,小、大剂量ASA组大鼠神经功能评分较对照组明显升高（P〈0.05）,24h梗死病灶体积与对照组比较分别减少54.48%和30.90%,病灶侧脑组织IL-6含量较对照组明显下降（P〈0.05）,SOCS-3mRNA含量较对照组明显上升（P〈0.05）,在术后12h～3d与对照组相比较均有显著性差异（P〈0.05）。结论 ASA药物预处理对脑缺血/再灌注损伤有保护作用,其可能机制与抑制IL-6的产生和上调SOCS-mRNA表达有关,小剂量ASA作用优于大剂量的ASA。     

氯胺酮对神经痛大鼠模型海马NR2B亚单位表达的影响

目的研究亚麻醉剂量氯胺酮对神经痛（NP）大鼠模型的镇痛作用及对海马NR2B亚单位的影响。方法采用坐骨神经慢性压迫法（CCI）制备大鼠NP模型。大鼠随机分为4组（n=6）：假手术组（SO组）、模型组（NP组）、K1、K2组。K1和K2组于CCI术后7～31d每天分别腹腔注射氯胺酮10、20mg／kg。各组分别于术前1d和术后3、7、21、31d测定大鼠术侧后爪痛阈;术后第31天,用RT—PCR和Westernblot的方法检测大鼠海马组织中NR2BmRNA和蛋白的表达水平。结果与SO组比较,NP、K1组和K2组术后痛阈明显降低（P〈0．05）。手术对侧海马组织中NR2B表达水平增高（P〈0．05）。与NP组比较,K1组和K2组术后痛阈升高（P〈0．05）,海马的NR2B蛋白表达降低（P〈0．05）。结论亚麻醉剂量氯胺酮可以部分反转NP模型痛觉过敏和海马的NR2B亚单位表达增高。