银杏叶提取物对大鼠创伤性颅脑损伤后MMP-2和MMP-9的影响

目的为探讨银杏叶提取物(GBE)对大鼠创伤性颅脑损伤后(TBI)脑水肿及MMP-2、MMP-9蛋白表达的影响。方法采用Feeney法建立大鼠TBI模型。80只健康雄性成年SD大鼠,采用随机数字表法分为4组(n=20):假手术组(Sham组)、TBI组、TBI+GBE组和TBI+强力霉素(DOX)组。于建模后1、3、7、14 d进行改良神经功能评分(m NSS);采用干湿重法测量损伤区脑组织含水量;免疫荧光和Western blotting测定脑组织中MMP-2、MMP-9蛋白表达变化。结果与Sham组比较,其他3组脑组织含水量和m NSS评分均显著升高(P0.05),脑组织中MMP-2和MMP-9蛋白表达上调(P0.05);与TBI组比较,TBI+GBE组和TBI+DOX组脑组织含水量和m NSS评分显著降低(P0.05),脑组织MMP-2和MMP-9蛋白表达下调(P0.05)。结论 GBE可减轻大鼠TBI后脑水肿,改善损伤后神经功能,其机制可能与抑制伤后脑组织MMP-2、MMP-9的表达相关。     

水通道蛋白4小RNA干扰技术优化亚低温治疗脑水肿

目的 应用针对靶向水通道蛋白4(aquapofin 4,AQP-4)的小RNA(siRNA)干扰技术优化亚低温减轻颅脑创伤(traumatic brain injury,TBI)后脑水肿程度的治疗效果.方法 构建沉默AQP-4 mRNA表达的siRNA质粒;液压打击法建立大鼠TBI模型,分TBI对照组、AQP-4 siRNA治疗组、亚低温治疗组、AQP-4 siRNA及亚低温联合治疗组;提取第1、3、5、7天脑组织总RNA和总蛋白,RT-PCR和Western blot方法 检测AQP-4的mRNA和蛋白表达水平;干/湿比重法和Evans蓝测定法观察大鼠TBI后不同时相脑组织含水量和血脑屏障通透性改变;实验动物予以神经功能缺陷综合评分.结果 亚低温在减轻TBI后脑水肿程度方面优于AQP-4 siRNA,但siRNA技术在沉默AQP-4表达方面强于亚低温,联合应用AQP-4 siRNA和亚低温在TBI后降低脑水肿程度方面获得最佳治疗效果.结论 靶向AQP-4的Si RNA干扰技术可优化亚低温在TBI后降低脑水肿方面的治疗效果.     

脑血疏口服液对大鼠脑缺血再灌注损伤后血脑屏障的影响

目的 探讨脑血疏口服液对大鼠脑缺血再灌注损伤后血脑屏障的影响。方法 将120只SD大鼠随机分为3组:假手术组、对照组,脑血疏组; 采用线栓法建立大鼠左侧大脑中动脉闭塞再灌注模型,缺血2 h后拔出线栓,恢复灌注24 h; 采用Longa FZ 5级评分法进行大鼠神经功能缺损评分; TTC染色计算脑梗死体积百分比; 运用干-湿重法测脑含水率; 通过伊文思蓝( EB)含量反映血脑屏障的损伤程度; 免疫组化检测基质金属蛋白酶-9(MMP-9)的表达水平。结果(1)假手术组大鼠在神经功能缺损评分、脑梗死体积、脑含水率均低于对照组(P<0.01); 脑组织中EB含量和MMP-9表达水平较对照组低(P<0.01);(2)脑血疏组大鼠的神经功能缺损评分较低、脑梗死体积较小,脑水肿程度较轻; EB含量和MMP-9表达水平均较对照组明显减少(P<0.01)。结论 脑血疏口服液对大鼠脑缺血再灌注损伤后血脑屏障具有保护作用,其机制可能是通过抑制MMP-9的表达。     

依达拉奉对局灶性脑缺血大鼠脑组织水通道蛋白-9mRNA表达的影响

目的探讨大鼠局灶性脑缺血后脑内水通道蛋白-9（AQP-9mRNA）表达与脑水肿动态变化的关系,评价依达拉奉的干预作用。方法216只雄性Sprague—Dawley（SD）大鼠随机分为3组：假手术组（A组,6只）,生理盐水组（B组,大脑中动脉阻断后6h、12h、24h、48h、72h、5d、7d7个时点,各6只）,依达拉奉处理组（C组,同B组）,术后即刻予以依达拉奉干预。分别测定脑组织含水量;实时荧光定量PCR（realtime quantitative polymerase chain reaction,RT—PCR）法检测mRNA表达;用HE染色方法观察病理形态学改变。结果B组大鼠MCAO后脑组织含水量呈上升趋势,48h达高峰,各时点均高于与A组（P〈0．05）。同时,AQP-9mRNA表达量与脑含水量呈相同趋势改变,相关性分析表明AQP-9mRNA表达量（r=0．788,P〈0．05）与脑组织含水量呈正相关。B组与C组相比,各时点脑组织含水量明显下降（P〈0．05）;AQP-9mRNA表达显著下调（P〈0．05）;组织病理提示脑水肿及神经元损伤程度减轻。结论大鼠脑缺血后脑内AQP-9mRNA表达与脑水肿变化呈正相关,提示AQP-9可能参与大脑中动脉阻断后的脑水肿形成。依达拉奉干预可减少AQP-9mRNA的表达,从而减轻大鼠大脑中动脉阻断后脑水肿,减少神经元坏死,改善神经功能预后。     

香芹酚通过抑制脑水肿与氧化应激反应保护大鼠 颅脑损伤

目的 探讨香芹酚对大鼠颅脑损伤（TBI）的保护作用及其机制。方法 SD大鼠50只,随机分为5组:假手术组、模型组、低剂量香芹酚（10 mg/kg）组、中剂量香芹酚（20 mg/kg）组、高剂量香芹酚（40 mg/kg）组,每组10只。Feeney氏自由落体法制备TBI模型,造模后1、3、7 d采用改良神经功能损害程度评分（mNSS）评估神经功能,干湿法测定脑组织含水量;ELISA法检测氧化应激因子丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽（GSH）、过氧化氢酶（CAT）以及化学定量法检测一氧化氮（NO）含量及一氧化氮合酶（NOS）活性。结果 香芹酚能显著改善大鼠TBI后神经功能,显著减轻TBI后脑水肿,显著降低损伤脑组织MDA、NO和NOS含量,显著增加损伤脑组织SOD、CAT和GSH含量。结论 香芹酚可通过减轻大鼠TBI后脑水肿、抑制氧化应激从而发挥神经保护作用。     

D-阿洛糖对小鼠脑缺血再灌注血脑屏障影响

目的研究D-阿洛糖对小鼠脑缺血再灌注损伤后血脑屏障的影响。方法 80只小鼠随机分为假手术组(sham组)、脑缺血模型组(MCAO组)、D-阿洛糖治疗组(D-allose组)、生理盐水对照组(NS组)。采用插线法制备小鼠大脑中动脉栓塞(MCAO)模型,尾静脉注射D-阿洛糖(300 mg/kg),运用改良小鼠神经功能缺损评分(m NSS)对小鼠脑缺血再灌注损伤程度评分;通过1%氯化三苯基四氮唑(TTC)染色,计算脑梗面积百分比;运用干-湿重法,测脑含水率;通过伊文思蓝(EB)含量反映血脑屏障的损伤程度;通过HE染色观察脑缺血再灌注损伤后梗死区的病理变化;采用免疫组化检测基质金属蛋白酶9(MMP-9)的表达。结果与MCAO组相比,D-allose可以明显降低小鼠脑缺血再灌注后神经功能缺损评分,减小小鼠脑梗死面积,减轻脑水肿,降低EB含量,减轻脑组织的病理损伤程度,并且明显减少MMP-9表达(P0.05)。结论 D-阿洛糖可以保护小鼠脑缺血再灌注后的血脑屏障,其机制可能与抑制MMP-9的表达有关。     

高渗氯化钠羟乙基淀粉40对大鼠脑缺血再灌注损伤后MMP-9和层粘连蛋白表达的影响

目的探讨高渗氯化钠羟乙基淀粉40(HSH)对大鼠脑缺血-再灌注(I/R)损伤后神经功能行为学评分,脑水肿情况,脑梗死体积以及脑组织中基质金属蛋白酶-9(MMP-9)和层粘连蛋白(Laminin)表达的影响。方法48只雄性SD大鼠随机分为假手术组、模型组、实验1组、实验2组。大鼠局灶性脑I/R损伤模型制备成功后120 min,假手术组和模型组静脉输注0.9%生理盐水,实验1组和2组分别静脉输注HSH 4 ml/kg和8 ml/kg。再灌注24 h后,行神经功能行为学评分,观察脑水肿情况,TTC染色测算脑梗死体积,用免疫印迹方法检测缺血区脑组织MMP-9和Laminin的表达。结果与假手术组比较,模型组神经功能行为学评分升高(P0.001);脑水肿加重;脑梗死体积增加(P0.001);MMP-9蛋白表达升高(P0.05);Laminin蛋白表达降低(P0.01)。与模型组比较,实验1组和2组神经功能行为学评分降低(P0.001);脑水肿缓解;脑梗死体积减少(P0.001);实验1组MMP-9蛋白表达减少(P0.01),Laminin蛋白表达升高(P0.05);实验2组MMP-9蛋白和Laminin蛋白表达均无明显变化。结论用HSH治疗大鼠脑I/R损伤后,大鼠神经功能行为学评分改善,脑水肿减轻,脑梗死体积减小,血脑屏障通透性降低,其机制可能与降低MMP-9和增加Laminin蛋白的表达有关。且保护作用以4 ml/kg剂量效果更佳。     

cAMP对大鼠颅脑损伤后神经功能及脑水肿的影响

目的 探讨蛋白激酶A（PKA）激活物cAMP对颅脑损伤（TBI）大鼠神经功能、脑水肿的影响。方法 选取120只成年雄性SD大鼠随机分为6组（每组20只）:假手术组（暴露硬脑膜而不给予液压打击）;高、中、低剂量cAMP组（TBI后1 h腹腔注射60、40、20 mg/kg PKA激活物8-Bromo-cAMP）;溶媒组（TBI后1 h腹腔注射cAMP溶媒二甲基亚砜10 μl）;模型组（液压打击处理）。TBI后48 h,采用神经损伤严重程度评分（NSS）评估神经功能,干湿重法测定脑含水量,免疫印迹法检查海马细胞外信号调节激酶1/2（ERK1/2）、非磷酸化缝隙连接蛋白43（NP-Cx43）、谷氨酸转运蛋白-1（GLT-1）及钠钾ATP酶的表达,高效液相色谱法检测海马谷氨酸（Glu）的含量。结果 TBI后,大鼠NSS明显增高（P<0.05）,脑含水量明显增加（P<0.05）,海马ERK1/2表达水平明显增加（P<0.05）,海马Glu含量明显增加（P<0.05）,而NP-Cx43、GLT-1、钠钾ATP酶表达水平明显降低（P<0.05）;cAMP干预后,显著逆转这些反应（P<0.05）,而且呈剂量依赖性。结论 大鼠TBI后,给予cAMP干预,激活PKA,可通过门卫效应抑制ERK1/2,使NP-Cx43、GLT-1及钠钾ATP酶水平明显增高,进一步降低Glu等脑毒性代谢产物、缓解脑水肿,从而改善大鼠神经功能。     

黄芪甲苷对脑缺血再灌注后血脑屏障的保护作用及IL-1β含量、MMP-9蛋白表达的影响

目的 探讨黄芪甲苷对大鼠脑缺血再灌注后血脑屏障的保护作用及其机制。方法 将SD大鼠72只随机等分为4组:假手术组、生理盐水对照组、小剂量黄芪甲苷治疗组(10 mg/kg)和大剂量黄芪甲苷治疗组(20 mg/kg),采用分光光度计法、酶联免疫吸附法及免疫组化法分别检测各组大鼠脑组织伊文氏蓝、IL-1β含量及MMP-9蛋白的表达水平。结果 与假手术组相比,生理盐水对照组脑组织伊文氏蓝含量明显增多、IL-1β含量显著增高、MMP-9蛋白的表达明显增强(P<0.01); 与生理盐水对照组相比,小剂量黄芪甲苷治疗组及大剂量黄芪甲苷治疗组脑组织伊文氏蓝含量均显著减少、IL-1β含量明显降低、MMP-9蛋白表达明显减弱(P<0.05); 小剂量黄芪甲苷治疗组与大剂量黄芪甲苷治疗组相比,伊文氏蓝、IL-1β含量及MMP-9蛋白表达无显著差异(P>0.05)。结论 黄芪甲苷对脑缺血再灌注后血脑屏障具有保护作用,这可能与其下调IL-1β含量、抑制MMP-9蛋白的表达有关。     

RNA干扰AQP4对创伤性脑水肿血脑屏障的保护作用

目的探讨RNA干扰（RNAi）水通道蛋白4（AQP4）对创伤性脑水肿血脑屏障（BBB）的保护作用。方法雄性成年Wistar大鼠,随机分为假手术组、对照质粒组、单纯创伤组和创伤后RNAi组。参照Marmarou法制作创伤性脑损伤（TBI）模型。采用侧脑室注射途径给药,应用免疫组织化学观测AQP4、微血管内皮细胞紧密连接闭合小环蛋白（ZO-1）,原位杂交法观测AQP4mRNA,光电镜观察脑组织超微结构。结果RNAi质粒可有效减少AQP4在受损脑组织的表达;RNAi组在各检测时间点脑组织含水量和BBB透性均小于TBI组和对照质粒组（P〈0．05）;TBI后RNAi组ZO-1表达水平各时间点明显高于单纯创伤组和对照粒组（P〈0．05）。结论TBI后损伤区AQP4的表达变化趋势和脑水肿的发展变化趋势相一致（r=0．982,P〈0．01）;应用RNA干扰途径减少AQP4表达,可有效保护TBI后脑水肿BBB结构的破坏。     

Potential contribution of hypoxia-inducible factor-1α, aquaporin-4, and matrix metalloproteinase-9 to blood-brain barrier disruption and brain edema after experimental subarachnoid hemorrhage

The current research aimed to investigate the role of hypoxia-inducible factor-1α (HIF-1α), aquaporin-4 (AQP-4), and matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) dysfunction and cerebral edema formation in a rat subarachnoid hemorrhage (SAH) model. The SAH model was induced by injection of 0.3 ml fresh arterial, non-heparinized blood into the prechiasmatic cistern in 20 s. Anti-AQP-4 antibody, minocycline (an inhibitor of MMP-9), or 2-methoxyestradiol (an inhibitor of HIF-1α), was administered intravenously at 2 and 24 h after SAH. Brain samples were extracted at 48 h after SAH and examined for protein expressions, BBB impairment, and brain edema. Following SAH, remarkable edema and BBB extravasations were observed. Compared with the control group, the SAH animals have significantly upregulated expressions of HIF-1α, AQP-4, and MMP-9, in addition to decreased amounts of laminin and tight junction proteins. Brain edema was repressed after inhibition of AQP-4, MMP-9, or HIF-1α. Although BBB permeability was also ameliorated after inhibition of either HIF-1α or MMP-9, it was not modulated after inhibition of AQP-4. Inhibition of MMP-9 reversed the loss of laminin. Finally, inhibition of HIF-1α significantly suppressed the level of AQP-4 and MMP-9, which could induce the expression of laminin and tight junction proteins. Our results suggest that HIF-1α plays a role in brain edema formation and BBB disruption via a molecular signaling pathway involving AQP-4 and MMP-9. Pharmacological intervention of this pathway in patients with SAH may provide a novel therapeutic strategy for early brain injury.     

甘露醇与尼莫地平联合应用对大鼠创伤性脑水肿以及水通道蛋白-4表达的影响

目的观察甘露醇与尼莫地平联合应用对大鼠挫裂伤脑组织水通道蛋白-4（AQP-4）表达的影响。方法成年Wistar大鼠54只,随机分为挫裂伤组、甘露醇治疗组、甘露醇与尼莫地平联合治疗组。采用文献报告的方法制作大鼠左顶叶皮层局限性脑挫裂伤模型。各组分别于脑挫裂伤后24、48、72h取挫伤区脑组织,检测其含水量以及AQP-4的表达。结果随着伤后时间的增加;各组脑组织含水量增加,AQP-4mRNA和AQP-4蛋白的表达均逐渐增高（P〈0．0．5）;与挫裂伤组相比较,甘露醇治疗组伤后各时间点脑组织含水量、AQP-4mRNA和AQP-4蛋白的表达均明显增加（P〈0．05）;甘露醇与尼莫地平联合治疗组伤后各时间点与前两组相比,脑组织含水量及AQP-4mRNA和AQP-4蛋白的表达均明显降低（P〈0．05）。结论脑挫裂伤后,AQP-4mRNA和AQP-4蛋白的表达增加;脯组织含水增加,甘露醇联合应用尼莫地平后,能够下调AQP-4mRNA和AQP-4蛋白的表达,有效缓解创伤性脑水肿。     

AQP-9在大鼠感染性脑水肿脑组织中的表达及意义

目的 探讨水通道蛋白-9(AQP-9)在内毒素脂多糖(LPS)致大鼠感染性脑水肿脑组织中的表达及意义. 方法 1月龄普通级SD大鼠128只采用随机数字表法分为生理盐水(NS)组(64只)和LPS组(64只),采用颈内动脉注射LPS制作大鼠感染性脑水肿模型,模型成功后每组均选取6h、12h、24h和48 h4个时间点,在不同时间点采用HE染色观察脑组织形态学改变;干湿重法测定脑组织含水量(BWC);甲酰胺法测定脑组织伊文思蓝(EB)含量;免疫组织化学法检测脑组织AQP-9蛋白的表达量:采用逆转录多聚酶链反应(RT-PCR)方法 检测AQP-9 mRNA的表达水平并对结果 进行相关性分析. 结果 HE染色结果 显示LPS组血管周围间隙增宽、炎性细胞浸润、胶质细胞体积增大肿胀、神经元空泡变性、细胞核固缩等.与NS组相比,LPS组6 h、12 h、24 h和48 hBWC、EB含量、AQP.9蛋白及AQP.9mRNA表达水平均增高.差异具有统计学意义(P<0.05).同时LPS组BWC和EB含量、AQP-9蛋白、AQP.9 mRNA表达量、AQP-9 mRNA表达量与EB含量、AQP-9蛋白与mRNA表达量均呈正相关. 结论 AQP-9可能参与感染性脑水肿的发生和发展.     

大鼠重型颅脑损伤急性期水通道蛋白4的表达

目的探讨水通道蛋白（AQP4）在大鼠重型脑外伤急性期的表达变化及其与脑水肿间的关系。方法49只成年雄性SD大鼠,随机分为对照组及实验组（伤后4h、8h、12h、24h、5d共5组）。制作重度冲击加速性损伤模型,分别于伤后4h、8h、12h、24h、72h、5d采用干湿比重法测脑组织含水量,原子吸收分光光度法测定Na^＋、K^＋含量,Evans Blue（EB）测定法观察大鼠血-脑屏障（BBB）通透性变化,半定量逆转录聚合酶链反应（RT-PCR）检测脑组织AQP4 mRNA表达及其变化。结果脑组织AQP4 mRNA在伤后4h开始表达上调,8h、12h依次增高,24h达到峰值（P〈0.05）,3d时仍维持较高水平,伤后5d有所降低。脑含水量、Na^＋含量的变化与AQP4 mRNA表达变化一致。经相关性分析,AQP4 mRNA的表达与脑含水量及脑EB含量均呈正相关（P〈0.05）。结论重型脑损伤急性期,AQP4 mRNA表达的变化与颅脑损伤后BBB的破坏及脑水肿的形成和发展密切相关。AQP4可能参与重型脑损伤后脑水肿的形成并起重要作用。     

Peripheral thermal injury causes early blood-brain barrier dysfunction and matrix metalloproteinase expression in rat

High mortality incidence after serious systemic thermal injury is believed to be linked to significant increases in cerebral permeability, ultimately leading to irreversible blood-brain barrier (BBB) breakdown. The aim of this study was to investigate whether disruption of microvascular integrity in a rat thermal injury model is associated with early matrix metalloproteinase (MMP) expression. A total of 35 Sprague-Dawley rats were studied in thermal injury and control groups, each group containing two subgroups, one for brain edema and Evans blue analysis and another for MMP mRNA analysis. Thermally injured animals were anesthetized and submerged vertically in 85 degrees C water to the neck for 6 seconds producing a third degree burn affecting 70% of the total body surface area. BBB integrity was determined by measuring amount of Evans blue after 7 hours of injury with a spectrophotometer. Brain edema was detected by calculating water content. Brain mRNA levels were determined with real-time PCR 3 and 7 hours post-injury. Brain water content was significantly increased after peripheral injury at hour 7. Evans blue leakage was also significantly increased at the same time, suggesting an impaired BBB function after injury. Expressions of MMP-2 and MMP-9 mRNA in brain were increased as early as 3 hours after injury and remained at hour 7. Our study demonstrated a significant increase in cerebral permeability that occurs after serious systemic thermal injury. The underlying mechanisms could be related to early expression of MMPs.     

The pathobiology of moderate diffuse traumatic brain injury as identified using a new experimental model of injury in rats

Experimental models of traumatic brain injury have been developed to replicate selected aspects of human head injury, such as contusion, concussion, and/or diffuse axonal injury. Although diffuse axonal injury is a major feature of clinical head injury, relatively few experimental models of diffuse traumatic brain injury (TBI) have been developed, particularly in smaller animals such as rodents. Here, we describe the pathophysiological consequences of moderate diffuse TBI in rats generated by a newly developed, highly controlled, and reproducible model. This model of TBI caused brain edema beginning 20 min after injury and peaking at 24 h post-trauma, as shown by wet weight/dry weight ratios and diffusion-weighted magnetic resonance imaging. Increased permeability of the blood-brain barrier was present up to 4 h post-injury as evaluated using Evans blue dye. Phosphorus magnetic resonance spectroscopy showed significant declines in brain-free magnesium concentration and reduced cytosolic phosphorylation potential at 4 h post-injury. Diffuse axonal damage was demonstrated using manganese-enhanced magnetic resonance imaging, and intracerebral injection of a fluorescent vital dye (Fluoro-Ruby) at 24-h and 7-day post-injury. Morphological evidence of apoptosis and caspase-3 activation were also found in the cerebral hemisphere and brainstem at 24 h after trauma. These results show that this model is capable of reproducing major biochemical and neurological changes of diffuse clinical TBI.     

Neuritin attenuates early brain injury in rats after experimental subarachnoid hemorrhage

Objectives: Early brain injury (EBI) is central to the pathological progress of subarachnoid hemorrhage (SAH). In this study, we determined if neuritin protects the brain against EBI in rats and discussed the role of apoptosis pathway mediated by endoplasmic reticulum stress in this neuroprotective route. Methods: A total of 96 male Sprague Dawley rats were divided into control, sham, SAH and SAH + neuritin groups. The rat SAH model was induced by injection 0.3 mL of nonheparinized arterial blood into the prechiasmatic cistern. Mortality assay, neurological scores, brain water content measurement, Evans blue dye assay, TUNEL stain assay and Western blot analysis were performed. Results: Neuritin significantly improved the neurological scores, brain water content, blood-brain barrier (BBB) and apoptosis compared with the control and sham groups within 24 h after SAH. TUNEL staining assay results demonstrated that apoptosis was ameliorated, MMP-9 expression was reduced, whereas GRP78, CHOP, caspase-12 and ASK1 levels were markedly preserved after neuritin application. Conclusions: Our study demonstrated that neuritin plays a neuroprotective role on EBI after SAH by attenuating BBB disruption, brain edema and apoptosis.