甘珀酸对兔脑血管痉挛时缝隙连接蛋白43磷酸化表达的影响

目的 探讨甘珀酸对兔实验性蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)时缝隙连接蛋白43(Cx43)磷酸化表达的影响.方法 建立兔二次SAH模型,脑池及静脉分别给予甘珀酸,脑血管造影及光镜观察分析基底动脉直径及形态学变化并应用Western blot检测基底动脉Cx43蛋白磷酸化表达的变化.结果 SAH组与正常组相比,脑血管造影及光镜观察结果 证实基底动脉痉挛明显;痉挛动脉肇磷酸化的Cx43(P-Cx43)蛋白表达显著升高,但去磷酸化的Cx43(NP-Cx43)蛋白表达显著减少.甘珀酸脑池处理组及静脉处理组与SAH组相比,脑血管造影及光镜观察结果 证实基底动脉痉挛显著减轻;痉挛动脉壁P-Cx43蛋白表达显著减少,但NP-Cx43蛋白表达显著升高.结论 SAH后,Cx43蛋白磷酸化表达发生变化,脑池或静脉给予甘珀酸能明显缓解SAH后CVS,其作用机制可能与基底动脉Cx43蛋白磷酸化表达变化有关.     

甘珀酸治疗蛛网膜下腔出血后脑血管痉挛的体内实验研究

目的 探讨缝隙连接抑制剂甘珀酸对实验性蛛网膜下腔出血后脑血管痉挛的治疗作用.方法 建立兔蛛网膜下腔二次出血模型,脑池及静脉分别给与缝隙连接抑制剂甘珀酸,脑血管造影及光镜观察分析基底动脉的直径及形态学变化,并应用Western blotting检测基底动脉Cx43蛋白的表达变化.结果 给与甘珀酸后,基底动脉狭窄程度及光镜下形态学变化显著减轻:单纯注血组(65.7±10.3)%,脑池处理组(91.2±6.4)%,静脉处理组(96.4±11.0)%,腑池预处理组(89.7±12.8)%;同时也显著抑制了痉孪后Cx43蛋白表达水平的升高:单纯注血组(57.2±2.8)%,脑池处理组(10.0±5.3)%,静脉处理组(15.2±1.7)%.结论 缝隙连接抑制剂甘珀酸可能对蛛网膜下腔出血后脑血管痉挛起到预防和治疗作用.     

蛛网膜下腔出血后基底动脉和软脑膜动脉缝隙连接蛋白表达与血管痉挛的关系

目的探讨蛛网膜下腔出血(SAH)后颅内基底动脉和软脑膜动脉痉挛与缝隙连接蛋白的相关性。方法选取健康成年雄性SD大鼠90只,并随机分为对照组、假手术组、SAH模型组、18β-甘草次酸(18β-GA)干预组(以下简称干预组)。采用改良版颅内视交叉前池二次注血法建立SAH模型。于造模后7 d对各组SD大鼠进行Garcia神经行为学评分;对全脑切片行HE染色法后运用软件系统测量大鼠软脑膜动脉直径;运用压力肌动图检测大鼠基底动脉直径;采用Western-blot法测量软脑膜动脉和基底动脉缝隙连接蛋白40(Connexin 40, Cx40)、Cx43和Cx45的表达水平,采用Pearson相关性分析血管痉挛与缝隙连接蛋白之间的相关性。结果与假手术组比较,SAH模型组大鼠神经行为学评分明显降低(P0.05),软脑膜动脉直径和基底动脉直径及其Cx40表达均降低(P0.05),而软脑膜动脉和基底动脉Cx43和Cx45表达升高(P0.05),与SAH模型组比较,干预组大鼠神经行为学评分高(P0.05),软脑膜动脉直径和基底动脉直径及Cx40明显增加(P0.05),而软脑膜动脉和基底动脉Cx43和Cx45表达均明显降低(P0.05)。软脑膜血管直径和基底动脉直径与Cx40表达水平均呈正相关(r=0.749,P0.05;r=0.866,P0.05),而与Cx43和Cx45均呈负相关(r=-0.836),P0.05;r=-0.697,P0.05;r=-0.411,P0.05;r=-0.979,P0.05)。结论 SAH后软脑膜动脉和基底动脉发生血管痉挛,且其血管直径与Cx40呈正相关,与Cx43、Cx45呈负相关。     

脑血管痉挛中缝隙连接蛋白Cx43磷酸化位点分析及S368位点与其关系的研究

目的 观察脑血管痉挛中缝隙连接蛋白Cx43的磷酸化位点及其S368位点磷酸化水平的变化,探讨其与脑血管痉挛的关系. 方法 新西兰大白兔78只按随机数字表法分为4组:正常对照组(n=6)、单纯脑池注血组(n=24)、甘珀酸(CBX)脑池处理组(n=24)和溶媒脑池处理组(n=24),后3组应用枕大池二次注血法建立兔蛛网膜下腔出血后脑血管痉挛模型及相应给药,并按1d、3d、7d、14d分成4亚组,每亚组6只.采用磷酸化蛋白富集试剂盒富集各组基底动脉中Cx43磷酸化总蛋白,再利用质谱技术鉴定出其磷酸化位点;应用Western blotting方法分析各组Cx43S368位点磷酸化水平的变化;通过数字减影血管造影技术(DSA)观察各组基底动脉直径变化情况. 结果 (1)质谱技术成功鉴定出Cx43的4个磷酸化位点,分别为Y265、S364、S365、S368.(2)Western blotting结果显示:正常对照组基底动脉Cx43 S368位点磷酸化水平较低(17.0％±2.3％);单纯脑池注血组及溶媒脑池处理组与正常对照组相比,Cx43 S368位点磷酸化水平在1d、3d、7d、14d各时间点均显著升高,差异有统计学意义(P＜0.05),且以7d表达最高,14d开始下降;CBX脑池处理组各时间点基底动脉Cx43 S368位点磷酸化水平显著低于单纯脑池注血组及溶媒脑池处理组,差异有统计学意义(P＜0.05).(3)DSA显示正常对照组第二次与首次造影基底动脉直径的百分比值平均为99.1％±1.3％,单纯脑池注血组、CBX脑池处理组、溶媒脑池处理组分别为66.1％±7.2％、91.3％±5.3％、63.7％±6.6％,CBX脑池处理组基底动脉直径显著狭窄于单纯脑池注血组,差异有统计学意义(P＜0.05). 结论 缝隙连接蛋白Cx43 S368位点磷酸化可能与脑血管痉挛密切相关,且其可能是CBX缓解脑血管痉挛的机制之一.     

胶质瘤转染Cx43cDNA与放疗的协同作用

目的探讨体外培养脑胶质瘤细胞转染Cx43cDNA与放疗是否存在协同作用及该作用与缝隙连接细胞间通讯功能(GJIC)的关系。方法LipofectAMINE2000介导质粒DNA转染,G418筛选,半定量RT-PCR及划痕荷载染料传输试验鉴定。分别以MTT法及流式细胞仪检测C6、C6-Non、C6-Cx43细胞放疗组和未放疗组的细胞增殖率及凋亡率,进而观察转染Cx43基因与放疗杀伤胶质瘤细胞是否有协同作用。结果①C6-Cx43细胞Cx43mRNA表达显著增加,染料传输能力较C6-Non明显增强;②转染Cx43cDNA,上调C6细胞GJIC功能后,放疗对脑胶质瘤细胞的毒性作用明显增强。结论①转染Cx43cDNA可上调C6细胞GJIC。②GJIC功能上调后,放疗对脑胶质瘤细胞的毒性作用明显增强,转染Cx43cDNA与放疗存在协同作用。③缝隙连接细胞间通讯可能是肿瘤转染Cx43cDNA与放疗存在协同作用的机制之一。     

Cx43/Cx45异型缝隙连接通道参与实验性蛛网膜下腔出血后脑血管痉挛的实验研究

目的探讨缝隙连接通道参与脑血管痉挛(CVS)的机制。方法选择健康新西兰大白兔36只,随机分为3组:正常对照组(每组n=12)、SAH-7d组(每组n=12)、SAH-7d+甘珀酸(CBX)组(每组n=12);用二次注血法制成兔SAH模型。应用脑血管造影技术观察造影前后各组基底动脉的血管直径,免疫共沉淀技术观察Cx43与Cx45在各实验组中相互作用的变化。结果脑血管造影显示单纯注血7d组较正常组基底动脉明显痉挛(P0.01),正常对照组及SAH-7d+CBX组基底动脉无明显痉挛,免疫共沉淀示Cx43与Cx45在体内的相互作用在SAH-7d组较正常组及SAH-7d+CBX组均明显增加(P0.01)。结论实验结果显示SAH后兔基底动脉较正常组明显痉挛,单纯出血组Cx43与Cx45组成的异型缝隙连接通道较正常组增加,而CBX能缓解SAH后的CVS及抑制Cx43/Cx45缝隙连接蛋白的高表达,即Cx43/Cx45异型通道的增加可能参与SAH后CVS的形成。     

缝隙连接阻断剂1-庚醇对脑血管痉挛的抑制作用

目的探讨缝隙连接在脑血管痉挛中的作用及观察其阻断剂在动物实验中的治疗作用。方法建立兔二次蛛网膜下腔出血模型,通过脑血管造影观察经动脉或池内注入缝隙连接阻断剂heptanol,对脑血管痉挛的抑制和治疗作用,并观察基底动脉的形态学变化。结果枕大池注血后血管造影显示基底动脉出现痉挛。在脑血管痉挛后,动脉给予heptanol对急、慢性脑血管痉挛有显著的治疗作用。预先枕大池注入heptanol再注血,造影显示基底动脉痉挛不明显(P>0.05),heptanol枕大池预处理后能显著抑制急、慢性期脑血管痉挛的形成。形态学检查发现,对照组第7d的基底动脉光镜见内皮细胞核染色质聚集,内弹力膜波纹状,平滑肌细胞分布稀疏等。动脉给药组和池内给药组也有类似变化,但范围局限、程度轻。结论缝隙连接阻断剂heptanol能有效抑制兔蛛网膜下腔出血后急性和慢性脑血管痉挛,体内试验表明缝隙连接在脑血管痉挛中可能发挥重要作用,应用其阻断剂heptanol具有显著的治疗作用。     

实验性自身免疫性脑脊髓炎脑内缝隙连接蛋白Cx43和Cx32的表达变化

目的 观察豚鼠实验性自身免疫性脑脊髓炎(EAE)模型脑内星形胶质细胞(AS)缝隙连接(GJ)蛋白Cx43与神经元缝隙连接蛋白Cx32表达变化及相互关系,以探讨胶质细胞和神经元表面缝隙连接与EAE模型损伤的关系.方法 采用免疫组化方法,显示EAE模型豚鼠脑内胶质细胞和神经元表面缝隙连接蛋白Cx43和Cx32的表达变化及分布规律.结果 EAE豚鼠模型建立成功后,脑内星形胶质细胞Cx43-Li细胞表达明显增加,呈斑点样或分枝样;神经元Cx32-Li细胞表达也增加,并存在一定时间相关性.结论 EAE豚鼠脑内Cx43和Cx32表达增加,提示EAE发生后星形胶质细胞与神经元间信息交流可能加强.     

抑胶素对C6脑胶质瘤细胞缝隙连接蛋白作用的体外实验研究

目的探讨抑胶素对C6脑胶质瘤细胞缝隙连接蛋白的影响。方法体外培养C6脑胶质瘤细胞,通过GFAP鉴定,应用免疫组化方法检测应用抑胶素前后C6脑胶质瘤细胞缝隙连接蛋白43(Cx43)的表达变化,并与临床上常用的抗肿瘤药物顺铂进行比较分析。结果抑胶素能够增加体外培养的C6脑胶质瘤细胞Cx43的表达,并呈剂量依赖性。结论抑胶素抑制脑胶质瘤细胞生长的作用机制之一可能与影响肿瘤细胞间的缝隙连接蛋白功能有关。     

外膜成纤维细胞在实验性脑血管痉挛中的作用

目的 在体外模拟血管壁外层结构,建立外膜成纤维细胞(AF)和平滑肌细胞(SMC)共培养,研究血管AF在蛛网膜下腔出血后脑血管痉挛中的作用.方法 (1)以多聚碳酸酯膜(PET膜)作为载体,将AF和SMC进行共培养.(2)模拟体内出血环境,在PET膜一侧接种AF细胞并加入含10-6 mol/L OxyHb的培养液,分别共培养24h、48h、72h,应用电镜观察SMC的长度.(3)提取各组AF缝隙连接蛋白Cx43进行RT-PCR半定量分析.结果 (1)扫描电镜测量发现,加入OxyHb处理的AF能使PET膜对侧未经OxyHb处理的SMC产生收缩(P＜0.001),且收缩程度与OxyHb处理AF细胞时间成正比.(2)AF缝隙连接蛋白Cx43半定量RT-PCR分析显示:24h、48h、72h组中Cx43mRNA平均相对含量较正常组上调(P＜0.01).结论 血管壁外层的AF受到OxyHb作用后可以引起未直接接触OxyHb的SMC发生持续收缩且缝隙连接蛋白Cx43mRNA表达上调,提示AF在蛛网膜下腔出血引起的脑血管痉挛中可能发挥重要作用.     

Mechanism of endothelin-1-induced contraction in rabbit basilar artery

BACKGROUND AND PURPOSE: Endothelin-1 (ET-1) is suggested to be a major cause of cerebral vasospasm after subarachnoid hemorrhage. However, the mechanism of ET-1-induced contraction in cerebral arteries remains unclear. This study was undertaken to demonstrate the possible role of protein tyrosine kinase (PTK), mitogen-activated protein kinase (MAPK), and protein kinase C (PKC) in ET-1-induced contraction. METHODS: PD-98059, damnacanthal, wortmannin, AG-490, genistein, calphostin C, and staurosporine were used to inhibit, or relax, the ET-1-induced contraction of basilar artery, studied with an isometric tension system. Immunoprecipitation of MAPK in ET-1-stimultated rings of basilar artery without or with the above inhibitors was studied with Western blot. RESULTS: (1) ET-1 produced concentration-dependent contraction and MAPK immunoprecipitation in rabbit basilar artery by activation of ET(A) but not ET(B) receptors. (2) MAPK inhibitors PD-98059 and U-0126 produced dose-dependent inhibition of ET-1-induced contraction. (3) The Src tyrosine kinase inhibitor damnacanthal, the phosphatidylinositol-3 kinase inhibitor wortmannin, and the Janus tyrosine kinase(2) inhibitor AG-490 abolished ET-1-induced contraction. (4) The PKC inhibitor staurosporine but not calphostin C abolished ET-1-induced contraction, and the PTK inhibitor genistein partially reduced ET-1-induced contraction. (5) In arteries precontracted by ET-1, PD-98059, U-0126, wortmannin, AG-490, genistein, and staurosporine produced concentration-dependent relaxation. (6) ET-1 induced a biphasic and time-dependent MAPK immunoprecipitation. (7) PD-98059, U-0126, genistein, AG-490, and damnacanthal, but not staurosporine or wortmannin, abolished the effect of ET-1 on MAPK immunoreactivity. CONCLUSIONS: This study demonstrated that MAPK may be involved in ET-1-induced contraction in rabbit basilar artery. MAPK is downstream of PTK, Src, and Janus tyrosine kinase pathways but may not be downstream of phosphatidylinositol-3 kinase pathways. The possible involvement of PKC in ET-1-induced contraction requires further investigation. Inhibition of these pathways may offer alternative treatment for ET-1-induced contraction and cerebral vasospasm.     

Characterization of the potent combined endothelin(A/B)-antagonist PD 142893 on cerebral vessels

A disturbed balance between endothelin (ET)-1 and nitric oxide (NO) seems to play a key role in the development of delayed cerebral vasospasm following subarachnoidal hemorrhage. Therefore, the effect of PD 142893 one of the first potent ET(A)- and ET(B)-receptor antagonists was characterized on the contraction and relaxation induced by ET-1 and bigET-1 on rat basilar artery (BA). Concentration-effect curves (CECs) were constructed by cumulative application of ET-1 or big ET-1 on BA ring segments with (E+) and without (E-) functionally intact endothelium. The effect of PD 142893 was determined by the modified pK(b) value and the shift between the CECs. PD 142893 inhibited the contraction by ET-1 and bigET-1. The pK(b)-values were for ET-1: 5.17 (E+) and 5.15 (E-) and for big ET-1: 5.34 (E+) and 5.57 (E-), respectively. A significant relaxation of pre-contracted segments by ET-1 or big ET-1 was neither observed in the presence nor in the absence of the receptor antagonist. The present data suggest a competitive inhibition of the ET(A)-receptor mediated contraction of cerebral arteries by PD 142893. The ET(B)-dependent relaxation of the cerebrovasculature is inhibited by PD 142893 at least in a comparable amount of contraction.     

实验性蛛网膜下腔出血后脑血管痉挛兔基底动脉Cx43蛋白表达的时相变化

目的 通过建立兔二次蛛网膜下腔出血实验模型,观察兔蛛网膜下腔出血后基底动脉缝隙连接蛋白Cx43表达的时相变化特点,初步探讨蛛网膜下腔出血后脑血管痉挛的形成机制.方法 选择健康新西兰大白兔30只,随机分为5组:正常对照组(n=6)和蛛网膜下腔出血模型组(1d、3d、7d和14d,n=6):建立兔二次蛛网膜下腔出血后脑血管痉挛实验模型,脑血管造影分析基底动脉的直径变化并应用Western Blot检测基底动脉Cx43蛋白的表达变化.对血管直径与Cx43表达变化情况进行相关分析.结果 成功建立兔二次蛛网膜下腔出血模型;脑血管造影显示注血后1d基底动脉即出现痉挛(85.7%±8.6%,P<0.05);7d时达高峰(66.5%±7.6%,P<0.01);14d时仍有痉挛(78.4%±8.2%,P<0.05)但程度较前缓解.Cx43蛋白表达在建立SAH模型后1d(38.6%±5.6%,P<0.05)、3d(50.2%±5.7%,P<0.05)、7d(57.8%±5.3%,P<0.01)、14d(32.4%±3.6%.P<00.05)均升高,其中7d为高峰,14d开始下降.Cx43蛋白表达的时相性变化与SAH后基底动脉直径的时相性变化相关系数为0.914.结论 实验结果 显示蛛网膜下腔出血后兔基底动脉缝隙连接蛋白Cx43的表达发生了时相性变化,并且Cx43蛋白表达强弱与蛛网膜下腔出血后脑血管痉挛程度在时程上存在正相关关系,表明缝隙连接蛋白Cx43可能参与蛛网膜下腔出血后脑血管痉挛的形成.

Abstract：

Objective The study was designed to explore the change of expression of connexin43(Cx43)protien in the model of subarachnoid hemorrhage(SAH)of rabbits,hoping to provide the basis to study the mechanism of cerebral vasospasm(CVS).Methods 30 New Zealand rabbits were divided into 5 groups:SAH group(1d,3d,7d,14d,n=6)and control group(n=6).The model of CVS following SAH was established.Digital subtraction angiography was performed to detect the change of the basilar arteries diameter.The expression of Cx43 protien in basilar arteries tissue at different time points following experimental SAH was examined by using western blotting analysis.The data were statistically analyzed using the bivariate correlations test.Results The model of SAH in rabbits was successfully established.All 30 rabbits were analyzed.Cerebral angiograms on 1d,3d,7d and 14d showed severe narrowing of the BAs,and on 7d showed the most narrowing and on 14d began to Relieve.Western blotting showed that the expression of Cx43 protein were detected in normal rabbit basilar arteries tissue.However,the expression of Cx43 protein increased gradually and significantly in models compared with that of control(P<0.05),which reached peak on 7d(P<0.01)and then decreased on 14d(P<0.05).There was positive correlation between expression of Cx43 and cerebral vasospasm.Conclusions The above results demonstrates at the first time that the Cx43 protein expression is altered after the SAH,and exhibits a time-dependent change.which might be connected with the development of CVS.In summary,our data demonstrates gap junctions may play an important role in the pathogenesis of cerebral vasospasm after SAH.     

Characterization of the potent combined endothelin(A/B)-antagonist PD 142893 on cerebral vessels

Abstract

A disturbed balance between endothelin (ET)-1 and nitric oxide (NO) seems to play a key role in the development of delayed cerebral vasospasm following subarachnoidal hemorrhage. Therefore, the effect of PD 142893 one of the first potent ET(A)- and ET(B)-receptor antagonists was characterized on the contraction and relaxation induced by ET-1 and bigET-1 on rat basilar artery (BA). Concentration-effect curves (CECs) were constructed by cumulative application of ET-1 or big ET-1 on BA ring segments with (E+) and without (E–) functionally intact endothelium. The effect of PD 142893 was determined by the modified pK_b value and the shift between the CECs. PD 142893 inhibited the contraction by ET-1 and bigET-1. The pK_b-values were for ET-1: 5.17 (E+) and 5.15 (E–) and for big ET-1: 5.34 (E+) and 5.57 (E–), respectively. A significant relaxation of pre-contracted segments by ET-1 or big ET-1 was neither observed in the presence nor in the absence of the receptor antagonist. The present data suggest a competitive inhibition of the ET(A)-receptor mediated contraction of cerebral arteries by PD 142893. The ET(B)-dependent relaxation of the cerebrovasculature is inhibited by PD 142893 at least in a comparable amount of contraction.     

Role of Ca(2+)-dependent K+ channels in erythrocyte lysate-induced contraction of rabbit cerebral artery.

K+ channel openers may be useful in the treatment of cerebral vasospasm following subarachnoid hemorrhage. However, the role of Ca(2+)-dependent K+ channel (KCa) openers in cerebral vasospasm remain unclear. This study was undertaken to examine the role of KCa in hemolysate-induced contraction of rabbit cerebral and peripheral arteries: 1. Iberiotoxin (IBX), a selective KCa channel blocker, produced more pronounced contraction in basilar than in those of carotid or femoral arteries, indicating KCa channels are important regulating factors in cerebral arteries; 2. NS1619, a selective KCa channel opener, abolished the contraction of basilar artery to erythrocyte lysate, a causative agent for cerebral vasospasm; 3. In rabbit basilar artery, NS1619 relaxed the contractions to IBX, erythrocyte lysate and KCl (20 and 60 mM), indicating that NS1619, besides opening KCa channels, possesses other vasodilating actions. We conclude that KCa channels are important factors in the regulation of cerebral vascular tension and KCa channel opener NS1619 may have dual relaxant actions in cerebral arteries.     

脑血管痉挛中差异表达蛋白质的实验研究

目的 建立兔脑血管痉挛(CVS)基底动脉和正常兔基底动脉双向凝胶电泳图谱,鉴定差异表达蛋白,从中发现有意义的CVS相关标志物.方法 采用双向凝胶电泳(2-DE)分离痉挛基底动脉和正常基底动脉总蛋白,银染显色,通过imagemaster5.0软件分析,从中选取差异表达蛋白质点,应用基质辅助激光解析飞行时间串联质谱(MALDI-TOF/TOF)鉴定差异表达的蛋白质.结果 获得重复性和分辨率较好的兔基底动脉双向凝胶电泳图谱;发现49个差异表达点,其中35个点得到鉴定,在CVS中高表达的有24个,其余11个在CVS中呈低表达.结论 建立了痉挛基底动脉和正常基底动脉双向凝胶电泳图谱,并应用质谱技术鉴定了35个差异表达点,这些差异表达蛋白质可能与CVS的发生相关.