大鼠脑缺血再灌注后大脑皮层神经细胞NOS表达与细胞凋亡及复方丹参的保护作用

目的:探讨大鼠局灶性脑缺血再灌注后大脑皮层神经细胞一氧化氮合酶(NOS)的表达与神经细胞凋亡的关系及中药复方丹参的保护作用.方法:采用大脑中动脉内栓线法造模,应用原位细胞凋亡检测方法观察神经细胞凋亡,用免疫组织化学方法检测大鼠大脑皮层神经细胞nNOS、iNOS的表达并做图像分析.结果:与假手术组比较,脑缺血冉灌注2 h后缺血侧大脑皮层缺血边缘区神经细胞nNOS、iNOS表达升高,并出现神经细胞凋亡,随着再灌注时间的延长,缺血侧大脑皮层缺血边缘区神经细胞iNOS表达明显增强,凋亡神经细胞数逐渐增多,至24 h达高峰,但神经细胞nNOS的表达增强不如iNOS表达明显.复方丹参保护组神经细胞nNOS、iNOS的表达和凋亡神经细胞数明显低于缺血再灌组.结论:脑缺血再灌注后缺血侧大脑皮层缺血边缘区神经细胞nNOS的表达增强,尤其是iNOS的表达显著升高,使NO产生增加可能是介导脑缺血再灌注后神经细胞凋亡的机制之一,复方丹参具有下调神经细胞nNOS、iNOS表达,减少NO生成,抑制细胞凋亡,减轻缺血再灌注对大鼠大脑皮层神经细胞损伤的作用.     

高血脂对大鼠脑缺血再灌注损伤后大脑皮质p38丝裂原活化蛋白激酶表达的影响

目的:检测高血脂对脑缺血再灌注损伤后缺血侧大脑皮质p38丝裂原活化蛋白激酶(p38MAPK)表达的影响。方法:喂食高脂饲料建立高血脂动物模型,随后线栓法建立脑缺血再灌注模型。Zea-Longa神经行为学评分法记录大鼠神经行为改变,TTC染色检测脑梗死灶体积,免疫组织化学及免疫印迹检测大脑皮质p38MAPK表达水平。结果:高血脂脑缺血再灌注后神经行为损伤加重,且梗死灶体积较单纯脑缺血再灌注明显扩大。与假手术组比较,单纯脑缺血再灌注组和高血脂脑缺血再灌注组大脑皮质p38MAPK表达明显增加,再灌注2 h时其表达量即开始增高,再灌注24 h时达高峰,而后又降低。相同再灌注时间点,与单纯脑缺血再灌注组比较,高血脂脑缺血再灌注组p38MAPK表达增高。结论:高血脂脑缺血再灌注损伤中,高血脂可上调大脑皮质p38MAPK表达,促进细胞凋亡的发生及加重炎症反应,进而加重缺血再灌注损伤。     

脑缺血再灌注后神经元和内皮细胞凋亡的差异与Bcl-2和P53达的意义

目的探讨大鼠局灶性脑缺血再灌注后神经细胞和血管内皮细胞凋亡的差异及其与Bcl-2和p53蛋白表达的关系.方法应用原位末端标记技术和免疫组化方法,检测神经细胞和血管内细胞凋亡及Bcl-2和p53蛋白表达.结果在缺血周围区,缺血再灌注2 h神经细胞和内皮细胞凋亡开始增多,12～24 h达高峰,之后逐渐减少,7～14 d降至假手术组水平;血管内皮细胞凋亡迟于神经元凋亡12～24 h.Bcl-2蛋白表达于缺血再灌注2 h开始增强,12～24 h达高峰,之后逐渐下降,至7～14 d接近假手术组水平.p53蛋白表达于缺血再灌注6 h开始增高,24～48 h达高峰,之后逐渐下降,至14 d与假手术组已无显著性差异.结论脑缺血再灌注损伤后血管内皮细胞凋亡迟于神经元凋亡,Bcl-2和p53蛋白参与细胞凋亡的调节.     

盐酸戊乙奎醚抑制脂多糖致急性肺损伤大鼠肺组织p38丝裂原活化蛋白激酶的活化

目的:观察盐酸戊乙奎醚(PHC)对脂多糖(LPS)致急性肺损伤(ALI)大鼠肺组织p38丝裂原活化蛋白激酶(p38MAPK)、c-jun氨基末端激酶(JNK)活化的影响。方法:SD大鼠随机分为对照组、LPS模型组（5 mg/kg LPS,iv）和LPS+PHC高、中、低(3.0、1.0和0.3 mg/kg)3个剂量组,每组6只,进行PHC对肺组织p38MAPK、JNK表达的量效性分析;另取大鼠在注入NS后即刻0（对照组）和注射LPS后2 h、4 h、6 h和12 h共5个时点,每时点6只,进行肺组织p38MAPK、JNK表达的时效性分析。蛋白免疫印迹法检测肺组织p38MAPK、JNK的表达。结果:LPS模型组大鼠肺组织磷酸化p38MAPK、JNK的表达显著高于对照组（P＜0.05);PHC高剂量组显著抑制LPS诱导的大鼠肺组织磷酸化p38MAPK表达（P＜0.05);PHC在造模后6 h时最能有效抑制磷酸化p38MAPK上调。与LPS模型组相比,PHC高、中、低剂量组磷酸化JNK的表达均无显著差异(均P＞0.05);造模后不同时点,PHC对磷酸化JNK的表达均无抑制作用。结论:PHC抑制LPS诱导的ALI大鼠肺组织p38MAPK活化,但不能抑制JNK活化,PHC对LPS诱导大鼠ALI的拮抗作用可能与其抑制p38MAPK的活化有关。     

脑缺血再灌注后神经元和内皮细胞凋亡的差异与Bcl—2和P53表达的意义

目的：探讨大鼠局灶性脑缺血再灌注后神经细胞和血管内皮细胞凋亡的差异及其与Bcl-2和p53蛋白表达的关系。方法：应用原位末端标记技术和免疫组化方法,检测神经细胞和血管内细胞凋亡及Bcl-2和p53蛋白表达,结果：在缺血周围区,缺血再灌注2h神经细胞和内皮细胞凋亡开始增多,12－24h达高峰,之后逐渐减少,7－14d降至假手术组水平;血管内皮细胞凋亡迟于神经元凋亡12－24h,Bcl-2蛋白表达于缺血再灌注2h开始增强,12－24h达高峰,之后逐渐下降,至7－14d接近假手术组水平,p53蛋白表达于缺血再灌注6h开始增高,24－48h达高峰,之后逐渐下降,至14d与假手术组已无显著性差异。结论：脑缺血再灌注损伤后血管内皮细胞凋亡迟于神经元凋亡,Bcl-2和p53蛋白参与细胞凋亡的调节。     

大鼠局灶性脑缺血—再灌注后尾壳核神经型一氧化氮合酶表达的变化

目的：探讨神经型一氧化氮合酶（Neuronal nitric oxide synthase,nNOS)在大鼠脑缺血后不同时程尾壳核内的变化。方法：应用大鼠大脑中动脉阻塞模型（MCAO），结合免疫细胞化学ABC法和图像定量分析技术进行研究。结果：缺血－再灌注早期（0h,1h,6h)尾壳核内nNOS免疫反应阳性神经元数量减少，细胞形态变圆，树突缩短，形态学参数开始下降，缺血－再灌注中期（24h,48h,72h)nNOS阳性神经元数量和形态学参数较前有一过性升高，但随后仍持续降低，缺血－再灌注后期（1W）nNOS阳性神经元数量继续下降，胞体浓缩，树突消失，细胞崩解，形态学参数降到最低，结论：脑缺血－再灌注后尾壳核内nNOS免疫反应阳性神经元损伤较重，持续时间长，后期更为严重，这可能会影响尾壳核功能的恢复。     

脑缺血再灌注后大鼠海马CA1区p-JNK表达和Bax的相关性的试验研究

目的:观察大鼠脑缺血再灌注后海马CA1区活化的JNK蛋白的表达情况,探讨缺血性脑损伤后神经细胞凋亡相关机理.方法:参照Zea Longa报道的线栓法制备缺血再灌注动物模型,随机将雄性SD大鼠分为正常对照组、缺血再灌注组及假手术对照组.并分别在不同时间点断头取脑制作标本,连续切片作p-JNK、Bax免疫组化染色及HE染色.结果:脑缺血再灌注后海马CA1区p-JNK表达与Bax的表达呈正相关(r=0.838,P＜0.01).p-JNK明显表达时间(2h)略早于Bax的表达,且产生的高峰时间亦稍早.结论:海马CA1区p-JNK表达与Bax的表达呈正相关.     

p38MAPK与脑缺血性损伤

丝裂原活化蛋白激酶 p38(p38MAPK)参与细胞生长、增殖、分化、死亡及细胞间的功能同步等多种生理过程。脑缺血神经元损伤后 ,p38MAPK早期被激活 ,在缺血区的胶质细胞和神经元表达增加 ,并表现出时间相关性 ,提示 p38MAPK信号通路在脑缺血神经元死亡过程中起着重要的调控作用。在信号通路水平阻断和调控 p38MAPK的表达和活性可能成为治疗缺血型脑卒中的新途径。     

SB203580对脑缺血再灌注损伤后基质金属蛋白酶9表达的影响

目的:通过检测抑制剂SB203580对缺血侧大脑皮质p38丝裂原活化蛋白激酶(p38MAPK)和基质金属蛋白酶9(MMP-9)表达的影响,探讨p38MAPK是否可以影响MMP-9的表达而参与高血脂加重脑缺血再灌注损伤。方法:喂食高脂饲料建立高脂血症动物模型,模型成功后随机分为抑制剂SB203580预处理的脑缺血2h再灌注24h组(SB组)、DMSO组、sham+SB组和sham+DMSO组,然后采用线栓法建立脑缺血再灌注模型。神经行为学评分观察神经行为损伤症状,TTC染色检测梗死灶体积,伊文思蓝染色检测血脑屏障通透性,免疫印迹检测p38MAPK和MMP-9表达水平,反转录PCR检测MMP-9mRNA水平。结果:与假手术组比较,SB组和DMSO组p38MAPK和MMP-9表达均明显增高。与DMSO组比较,SB组p38MAPK和MMP-9表达明显降低,差异有统计学意义。且SB组MMP-9mRNA水平较DMSO组明显降低,神经行为损伤程度、梗死灶体积和血脑屏障通透性亦明显降低,差异均有统计学意义。结论:高脂血症脑缺血再灌注损伤中,p38MAPK可上调MMP-9表达,促进细胞凋亡的发生及增加血脑屏障通透性,进而加重脑缺血再灌注损伤。     

胡黄连苷Ⅱ干预脑缺血/再灌注损伤后p38丝裂原活化蛋白激酶信号通路的作用机制

目的 探讨胡黄连苷Ⅱ对脑缺血/再灌注损伤后p38丝裂原活化蛋白激酶(p38 MAPK)通路的影响及其神经保护作用机制.方法 成年健康雄性Wistar大鼠150只,应用线栓法建立大鼠大脑中动脉闭塞/再灌注(MCAO/R)模型,按照随机对照原则,动物分为假手术组、模型组、胡黄连苷组、茴香霉素(p38 MAPK激活剂)组、茴香霉素+胡黄连苷组和SB203580(p38 MAPK抑制剂)组和SB203580+胡黄连苷组.改良神经功能评分(mNSS)法评价大鼠神经行为功能,HE染色观察神经细胞的形态结构,TUNEL法检测细胞凋亡,免疫组织化学法检测脑组织磷酸化p38 MAPK(p-p38 MAPK)表达水平,Western blotting检测大鼠皮质区p-p38 MAPK、磷酸化MAPK激活的蛋白激酶2(p-MK2)、磷酸化胞质磷脂酶A2(p-cPLA2)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α).结果 假手术组大鼠无神经功能缺损.模型组大鼠神经功能缺损评分升高,皮质区神经细胞损伤加重,脑梗死体积增大,凋亡细胞增多,p-p38 MAPK、p-MK2、p-cPLA2、IL-6及TNF-α蛋白表达增强.胡黄连苷组、SB203580组和SB203580+胡黄连苷组大鼠皮质区神经元损伤较轻,凋亡细胞数量明显减少,p-p38 MAPK、p-MK2、p-cPLA2以及IL-6蛋白表达较模型组明显降低.茴香霉素组、茴香霉素+胡黄连苷组各项指标与模型组相近,脑梗死体积较大,神经功能缺损较重,p-p38 MAPK、p-MK2、p-cPLA2以及IL-6蛋白表达升高.结论 脑缺血损伤后激活p38 MAPK信号通路介导神经元凋亡和炎症反应,胡黄连苷Ⅱ可能通过降低p38 MAPK通路的活化,抑制神经元凋亡和炎症反应从而保护神经系统.     

Activation and autophosphorylation of apoptosis signal-regulating kinase 1 (ASK1) following cerebral ischemia in rat hippocampus

We investigated the expression, activation and autophosphorylation of apoptosis signal-regulating kinase 1 (ASK1) in rat hippocampus after cerebral ischemia. The in vitro kinase assay showed that ASK1 activity gradually increased while the autophosphorylation of ASK1 gradually reduced during 5, 15 and 30 min of cerebral ischemia. At various time points of reperfusion, the activation and autophosphorylation of ASK1 reached a high point at 30 min and reduced to basal level at 6 h and then slightly increased at 3 d compared with sham operation. Both of the increases of ASK1 activation and autophosphorylation were suppressed by N-acetylcysteine, a well-known antioxidant, which was administered to the Sprague-Dawley rat 20 min before cerebral ischemia. Immunoprecipitation and Western blotting assay showed that there was no obvious change in the amount of ASK1 at each time point compared with sham control. Our results suggest that ASK1 protein which is known as an upstream mediator of JNK/p38 mitogen-actived protein kinase (MAPK) activation may play an important role in signal transduction in response to ischemic stress, given the fact that activation of JNK/p38 MAPK and subsequent phosphorylation of c-Jun are involved in the apoptotic pathway in cerebral ischemia.     

NGF对局灶性脑缺血再灌注后大鼠海马CHOP mRNA及蛋白表达的影响

探讨NGF对局灶性脑缺血再灌注后大鼠海马神经元CHOPmRNA及蛋白表达的影响。用线栓法制作大鼠右侧大脑中动脉阻塞再灌注模型(MCAO),应用原位杂交方法检测CHOPmRNA的表达;应用免疫组织化学SABC法检测CHOP蛋白表达;应用显微图像分析系统进行分析。结果显示:假手术组大鼠海马CHOPmRNA及蛋白表达极少;缺血组较假手术组CHOP表达mRNA和蛋白均显著增加(P<0.01),缺血再灌注3h后CHOPmRNA表达明显增加,24h达高峰,48h开始显著下降,72h接近对照组水平,CHOP蛋白在缺血再灌注12h时明显表达增高,24h达到高峰,72h显著下降,但仍高于对照组水平(P<0.01);在缺血再灌注12、24、48h,NGF组CHOPmRNA及蛋白表达明显低于缺血组(P<0.01)。本研究表明,外源性NGF能显著抑制局灶性脑缺血再灌注后CHOPmRNA及蛋白表达,提示NGF可能对脑缺血再灌注损伤后的海马神经元有保护作用。     

MNNG对哺乳类细胞JNK/SAPK及p38MAPK作用及其信号源研究

目的:研究低浓度烷化剂N-甲基-N' -硝基-N-亚硝基胍(MNNG)对JNK/SAPK及p38 MAPK通路的作用及其信号源。方法: 分别测定完整Vero细胞和脱核Vero细胞的JNK/SAPK及p38 MAPK酶活性,并比较其结果。 结果:低浓度MNNG在完整Vero细胞和脱核Vero细胞中均抑制JNK/SAPK酶活性;在p38 MAPK通路中,完整Vero细胞表现酶活性升高,而脱核Vero细胞该激活作用消失。 结论: 低浓度MNNG抑制JNK/SAPK的作用不依赖于核内信号,而对p38 MAPK的激活作用依赖与于核内信号。     

脑缺血再灌注后神经元和内皮细胞凋亡与Bc1-2和Bax表达的时相关系

目的　探讨大鼠局灶性脑缺血再灌注后受损伤的神经细胞和血管内皮细胞凋亡 ,以及Bcl 2和Bax蛋白表达与再灌注时间的关系。　方法　应用原位末端标记 (TUNEL)技术和免疫组织化学方法 ,分别观察脑缺血再灌注 2h、6h、12h、2 4h、2d、3d、7d、14d和 2 1d等不同时间点神经细胞和血管内皮细胞凋亡数及Bcl 2和Bax蛋白的表达。　结果　 1.脑缺血周围区 ,再灌注 2h神经细胞和内皮细胞凋亡开始明显增多 ,12～ 2 4h达高峰 ,之后逐渐减少 ,7～ 14d降至假手术组水平 ;血管内皮细胞凋亡迟于神经元凋亡约 12h。 2 .Bcl 2蛋白表达于缺血再灌注 2h开始逐渐增强 ,12～ 2 4h达高峰 ,之后逐渐下降 ,至 7～ 14d接近假手术组水平 ;3.Bax蛋白表达于缺血再灌注 6h开始逐步增高 ,2 4～ 4 8h达高峰 ,之后逐渐下降 ,至 14d与假手术组已无显著性差异。 4 .Bcl 2表达与细胞凋亡的时相变化基本一致 ,Bax表达时相迟于细胞凋亡。　结论　细胞凋亡是脑缺血再灌注损伤细胞死亡的形式之一 ,血管内皮细胞凋亡迟于神经细胞凋亡 ,Bcl 2和Bax参与细胞凋亡的调节。     

ORF61 protein of Varicella-zoster virus influences JNK/SAPK and p38/MAPK phosphorylation

Recently, it was demonstrated that the Varicella-zoster virus (VZV) infection led to an activation of MAP kinases. The viral protein encoded by ORF61 is a major effector of JNK/SAPK and p38/MAPK phosphorylation. ORF61 shows homology to HSV-1 ICP0, a multifunctional protein that influences the activity of c-Jun in infected cells. Stable expression of ORF61 in a MeWo derived cell line gave rise to two specific effects: (i) a major decrease of VZV replication and (ii) a strongly elevated basal JNK/SAPK phosphorylation but a reduced p38/MAPK phosphorylation, which were both altered following infection. A dose-dependent inhibition of JNK/SAPK in MeWo/61 cells resulted in a step-by-step increase of VZV replication. These findings indicate (i) that ORF61 is responsible for the elevated JNK/SAPK phosphorylation and (ii) that the VZV replication and the JNK/SAPK phosphorylation are related inversely. Compared to MeWo cells, the basal phosphorylation of downstream targets c-Jun and ATF-2 was reduced following ORF61 expression but restored after infection. Subsequent cascades to induce inflammatory responses were activated insignificantly; cascades to activate apoptotic events also remained silent. These data point towards an important role of ORF61 in the fine-regulation of activation of the MAPK pathways and their downstream targets to optimize the availability of cellular factors involved in VZV gene expression.     

磷酸化的丝裂原活化蛋白激酶在大鼠睾丸的表达

目的研究丝裂原活化蛋白激酶(MAPKs)的3个亚家族成员细胞外信号调节激酶(ERK)、c-Jun N-端激酶(JNK)和p38 MAPK的活化形式在睾丸中的定位,了解MAPKs在生精过程中所起的作用。方法免疫组织化学方法检测正常大鼠睾丸中磷酸化的p-ERKJ、NK、p38 MAPK的表达情况。结果正常大鼠睾丸中p-ERK主要分布于精原细胞、细线前期到粗线期的初级精母细胞以及9~12期长形精子细胞的细胞核,p-JNK则主要位于支持细胞与支持细胞、支持细胞与生精细胞(尤其是19期精子细胞)之间,而p-p38 MAPK除了在生精小管的部分细胞胞质中有分布外,其表达最明显的部位是在间质细胞的细胞质。结论ERKJ、NK和p-38 MAPK分别定位于正常大鼠睾丸内的不同部位,提示MAPKs不同的亚家族成员分别在精子发生的不同环节中发挥主要作用。ERK可能参与生精细胞增殖、分化的信号转导,JNK则可能通过调节细胞的黏附而最终影响生精细胞的迁移与精子释放过程,而p38 MAPK除了可能与JNK一起参与精子释放的调节外,最主要的作用可能是睾酮合成分泌的调节。     

Effect of Emodin on Endoplasmic Reticulum Stress in Rats with Severe Acute Pancreatitis

This study aimed to investigate the protective effect of emodin on endoplasmic reticulum (ER) stress in rats with severe acute pancreatitis (SAP) and the underlying molecular mechanism. Sprague–Dawley male rats were randomly divided into sham operation group, SAP model group, and emodin treatment group. SAP was constructed through injecting sodium taurocholate into pancreatic and biliary duct in rats. Half an hour before establishing the animal model, emodin or sodium carboxymethylcellulose was intragastrically administrated to the rats in respective group. Rats were killed at 3, 6, and 12 h postdisease induction. The amylase, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels in serum, pancreatic histopathology, acinar ER ultrastructure, protein expression of Bip, IRE1α,TRAF2, ASK1, p-JNK, and p-p38 MAPK in pancreas were examined. Sodium taurocholate induced pancreatic injury and ER lumen dilated in exocrine pancreas in rats at 3-, 6-, and 12-h time points. ER stress transducers Bip, IRE1α, and their downstream molecules TRAF2, ASK1 in pancreatitis were upregulated. Furthermore, phosphorylation of JNK and p38MAPK in pancreas was increased, which induced high expression level of inflammatory cytokines such as TNF-α and IL-6. Treatment with emodin obviously ameliorated pancreatic injury and decreased the release of amylase and inflammatory cytokines. Further studies showed that emodin significantly decreased the expression of Bip, IRE1α, TRAF2, and ASK1, inhibited phosphorylation of JNK and p38 MAPK in pancreas in rats at all time points. Emodin could reduce pancreatic injury and restrain inflammatory reaction in SAP rats partly via inhibiting ER stress transducers IRE1α and its downstream molecules.     

缺血预处理快速效应对兔急性缺血脊髓的保护作用

目的:探讨缺血预处理快速相对兔腹主动脉短暂阻断致缺血脊髓的保护作用。方法:36只雄性新西兰兔随机分成3组(n=12):即缺血再灌注损伤组(IR组)、缺血预处理组(IPC+IR组)及假手术组(Sham组)。IR组阻闭兔腹主动脉肾下段20min,复制兔脊髓缺血损伤模型;IPC+IR组预先阻闭腹主动脉肾下段6min,再灌注30min后再次阻闭腹主动脉肾下段20min;Sham组除不夹闭腹主动脉外,其余处理同IR组。再灌注后8h、12h、24h和48h分别对动物神经功能评分,然后,处死动物取脊髓(L_5-7),分别行组织病理学观察及测定脊髓组织中Na⁺,K⁺-ATP酶的活性。结果:Sham组及IPC+IR组神经功能评分各时点均明显高于IR组(P＜0.01);Sham组及IPC+IR组脊髓前角正常神经细胞数明显多于IR组(P＜0.01);Sham组及IPC+IR组脊髓组织中Na⁺,K⁺-ATP酶的活性明显高于IR组(P＜0.01)。结论:缺血预处理快速相对兔急性缺血脊髓有显著的保护作用,这种保护作用可能与稳定Na⁺,K⁺-ATP酶的活性有关。     

Differential activation of neuronal ERK, JNK/SAPK and p38 in Alzheimer disease: the 'two hit' hypothesis.

There are multiple lines of evidence showing that oxidative stress and aberrant mitogenic signaling play an important role in the pathogenesis of Alzheimer disease. However, the chronological relationship between these and other events associated with disease pathogenesis is not known. Given the important role that mitogen-activated protein kinase (MAPK) pathways play in both mitogenic signaling (ERK) and cellular stress signaling (JNK/SAPK and p38), we investigated the chronological and spatial relationship between activated ERK, JNK/SAPK and p38 during disease progression. While all three kinases are activated in the same susceptible neurons in mild and severe cases (Braak stages III-VI), in non-demented cases with limited pathology (Braak stages I and II), both ERK and JNK/SAPK are activated but p38 is not. However, in non-demented cases lacking any sign of pathology (Braak stage 0), either ERK alone or JNK/SAPK alone can be activated. Taken together, these findings indicate that MAPK pathways are differentially activated during the course of Alzheimer disease and, by inference, suggest that both oxidative stress and abnormalities in mitotic signaling can independently serve to initiate, but both are necessary to propagate, disease pathogenesis. Therefore, we propose that both 'hits', oxidative stress and mitotic alterations, are necessary for the progression of Alzheimer disease.