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.     

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.     

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.     

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.     

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。     

慢性脑低灌注大鼠海马缝隙连接蛋白32和36的表达变化

目的：观察慢性脑低灌注大鼠海马组织中缝隙连接蛋白（Cx）32和Cx36的变化,探讨其在慢性脑低灌注认知功能损害中的作用。方法：双侧颈总动脉永久性结扎（2VO）制作慢性脑低灌注模型,Morris水迷宫检测2VO大鼠空间学习记忆能力变化,免疫组化检测2VO大鼠海马各区Cx32和Cx36的表达水平。结果：慢性脑低灌注大鼠的空间学习记忆能力较假手术对照组显著下降,海马Cx32和Cx36的表达也有降低。结论：Cx32和Cx36可能参与了慢性脑低灌注导致的认知功能损害。     

缝隙连接、缝隙连接蛋白43与癫痫

<正>缝隙连接(Gap junction,GJ)为细胞膜上的一种特殊结构,构成相邻细胞间的通道,离子及小分子可经其进行细胞间转运,通过缝隙连接可以介导细胞间的通讯和电传导,是电突触的基本结构[1]。缝隙连接蛋白(Connexin,Cx)是缝隙连接的组成部分,缝隙连接蛋白43(Cx43)在哺乳动物的中枢神经系统中数量最多,表达活性最强,其主要在脑组织星形胶质细胞中表达,和细胞信息传导等多个方面关系密切。Cx43在中枢神经系统的同步化放电、信息传递及生长发育     

癫痫幼鼠海马和颞叶皮质区缝隙连接蛋白43和突触体素表达的变化

目的观察神经元缝隙连接蛋白43（Cx43）和突触体素（synaptophysin P38）在戊四氮（PTZ）点燃癫痫幼鼠海马及颞叶皮质区中的表达，探讨两者与癫痫的关系及其在癫痫形成中的作用。方法将50只21日龄Wistar大鼠分为对照组和实验组。实验组采用PTZ点燃癫痫幼鼠，按点燃进程分为Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级及Ⅳ级发作组。采用免疫组化和图像分析技术，观察海马及颞叶皮质区Cx43和P38表达的变化。结果应用PTZ点燃后，实验各组幼鼠海马及颞叶皮质区Cx43和P38的表达明显高于对照组（P〈0．01），且随发作级别的增高，幼鼠海马及颞叶皮质各区Cx43和P38的表达均增加。但各组间海马区和颞叶皮质区Cx43和P38的表达情况的比较差异无统计学意义（P〉0．05）。结论Cx43和P38的表达水平与癫痫的发生发展有密切关系，为研究小儿癫痫的病因及发病机制提供依据。     

缝隙连接蛋白43与创伤后脑水肿相关性研究

目的探讨缝隙连接蛋白43（Cx43）与创伤后脑水肿的相关性。方法大鼠脑损伤前2h经侧脑室注射Cx43特异性阻断剂反义寡核苷酸（ODNs）或生理盐水，用Feeney＇s自由落体法制作局灶性脑损伤动物模型，通过星形胶质细胞的特异性标记物-胶质纤维酸性蛋白（GFAP）免疫荧光染色，观察脑皮质区星形胶质细胞的形态、数量的变化，同时观察脑组织的水肿情况。结果脑损伤后生理盐水对照组GFAP标记的星形胶质细胞数量较ODNs预处理组明显增多（P〈0．05），细胞胞体较肥大；ODNs预处理组脑水肿较生理盐水对照组明显减轻（P〈0．05）。结论阻断Cx43可减轻脑创伤后脑水肿的程度，Cx43参与了脑损伤后的脑水肿的形成。     

癫痫大鼠海马缝隙连接蛋白43的表达及生胃酮的保护作用

目的研究癫痫大鼠海马星形胶质细胞缝隙连接蛋白43(Connexin43,CX43)表达及缝隙连接蛋白阻滞剂生胃酮对其表达的影响。方法用免疫组化法检测癫痫发作后各时间点大鼠海马星形胶质细胞CX43免疫反应阳性表达。同时观察致痫前给予不同剂量生胃酮对大鼠海马星形胶质细胞CX43免疫反应阳性表达的影响。结果对照组大鼠海马星形胶质细胞CX43可见少量散在表达。癫痫组大鼠海马星形胶质细胞CX43表达1h即可见增加,并随时间延长而增加,72h达高峰。生胃酮各组大鼠海马星形胶质细胞CX43免疫反应阳性表达较同一时间点癫痫组低(P<0.01),且与生胃酮剂量呈负相关(P<0.01)。结论癫痫大鼠海马缝隙连接蛋白43的表达与癫痫发病机制密切相关。缝隙连接蛋白阻滞剂生胃酮影响缝隙连接蛋白43表达,具有肯定的神经保护作用。     

Gap junction protein connexin43 (GJA1) in the human glaucomatous optic nerve head and retina

Primary open angle glaucoma is characterised by the progressive and irreversible death of retinal ganglion cells. Experimental evidence suggests that the initial site of injury to the retinal ganglion cell is at or near the lamina cribrosa or in the peripapillary retina. However, the mediators of axonal injury remain poorly understood. The purpose of this study was to investigate the expression of the gap junction protein connexin43 (GJA1) in the human glaucomatous optic nerve head and retina as a potential mediator of axonal injury. Using affinity isolated polyclonal antibodies to the C-terminal segment of human connexin43, the expression of connexin43 was determined in post-mortem human eyes with primary open angle glaucoma and age-matched controls. In normal eyes, connexin43 was present on glial fibrillary acidic protein (GFAP)-positive astrocytes in the retinal ganglion cell layer and optic nerve head. In glaucomatous eyes, increased connexin43 immunoreactivity was observed at the level of the lamina cribrosa and in the peripapillary and mid-peripheral retina in association with glial activation. This novel finding may suggest that gap junction communication is a potential mediator of retinal ganglion cell injury in glaucoma.     

辛醇对红藻氨酸致痫大鼠的保护作用及其对海马组织连接蛋白43的影响

目的 研究辛醇对红藻氨酸(kainic acid,KA)致痫大鼠海马组织连接蛋白43(connexin43,CX43)表达的影响及其抗痫效应.方法 采用行为学评分评价KA致痫及辛醇腹腔注射后致痫大鼠的痫性发作程度和潜伏期,应用免疫组织化学方法检测海马CX43的表达.结果 KA组CX43的表达较正常对照组明显增高(P<0.01);辛醇组CX43的表达也较正常对照组明显增高(P<0.01),但较KA组明显下降.致痫后3h内辛醇组痫性发作评分较KA组明显下降(P<0.01),潜伏期明显延长(P<0.01).结论 反复痫性发作后CX43的表达增加.辛醇能够减少CX43表达,降低痫性发作的评分,延长痫性发作的潜伏期,具有较明显的抗癫痫效应.

Abstract：

Objective To study the effects of octanol on the expression of connexin 43 in the brain of epilepsy-rats induced by kainic acid and the anti-epileptic effect of octanol. Methods The epilepsy-rats induced by kainic acid and treated by octanol was assessed by behavior score. The expression of CX43 in the hippocampal tissue was measured by immuno-histochemistry. Results The expression of CX43 in the group of epilepsy-rats induced by kainic acid was higher than that in control group( P <0. 01) ;the expression of CX43 in the group treated by octanol was higher than that in control group( P <0. 01) ,but lower than the group of epilepsy-rats induced by kainic acid;the Patel score of the rats in the group treated by octanol was lower than the group only induced by kainic acid within 3 hours after the induction (P <0. 01) ,and the latency was longer (P <0.01). Conclusions After the epileptic seizure repeatedly, the expression of CX43 was upregulated. Octanol could reduce the expression of CX43, decrease the Patel score,and extend the latency of epileptic seizure. It has obviously anti-epileptic effect.     

Ischemia-induced cellular redistribution of the astrocytic gap junctional protein connexin43 in rat brain

The distribution and levels of the astrocytic gap junction protein, connexin43 (Cx43) was analyzed in various regions of brain as a function of time after neuronal loss and consequent reactive gliosis induced by bilateral carotid occlusion in rats. In the striatum 2 days after induction of ischemia, immunostaining intensity for Cx43 increased in animals exhibiting mild to moderate striatal damage, whereas areas of reduced staining surrounded by elevated levels of Cx43 immunoreactivity were observed in animals with severe ischemic damage. Immunolabelling of glial cell bodies was evident in ischemic, but not normal, striatum. Similar, though less dramatic, changes were seen at 7 days post-ischemia. Compared with the fine punctate pattern of Cx43 staining seen in normal striatum, ischemic striatal areas contained large aggregates of punctate profiles. In the hippocampus, increased immunostaining was seen at 2 and 7 days post-ischemia and, unlike normal hippocampus, neurons in the CA3 pyramidal cell layer were surrounded by a network of Cx43-immunoreactive puncta at the latter survival time. Immuno-EM analysis of ischemic tissue revealed numerous immunolabelled gap junctions among astrocytic processes in the vicinity of degenerating neurons and elevated levels of intracellular Cx43 immunoreactivity in astrocytic processes and cell bodies. No differences in protein levels or phosphorylation states of Cx43 were detected in either hippocampus or striatum by Western blot analyses of ischemic and control tissue. These results suggest that astrocytes respond to an ischemic insult by reorganizing their gap junctions, that the qualitative nature of their response is dependent on the severity of neuronal damage or loss, and that a pool of Cx43 normally undetectable by immunohistochemistry may contribute to the ischemia-induced elevations of immunolabelling for this protein.     

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。     

KA注射致痫大鼠脑组织中CX43的表达及其意义

目的探讨CX43与癫痫之间的关系。方法利用免疫组织化学方法、Westernblot方法测定KA致痫后大鼠不同脑区、不同时程的CX43的分布及表达。结果KA致痫后大鼠的大脑皮层及海马均有CX43阳性表达。KA致痫后3h大鼠的海马各区及皮层CX43阳性细胞数逐渐增多，并持续上升，时程越长阳性细胞数目越多。上述变化在海马比皮层明显。结论星形胶质细胞的缝隙连接与癫痫的发生和发展上有密切联系。