局灶低温及全脑低温对大鼠创伤性脑损伤后IL-1β与TNF-α的影响研究

目的研究局灶低温及全脑低温治疗对SD大鼠创伤性脑损伤后脑水含量、Na 含量及IL-1β、TNF-α的影响,以探讨局灶低温对创伤性脑损伤的治疗作用及可能机制。方法采用自由落体打击装置造成大鼠创伤性脑损伤,分别于伤后30min开始进行全脑降温、25℃水脑局灶降温治疗,治疗结束后在相应时相点断头处死,采用相关的方法测定伤灶脑组织含量,Na 含量、白细胞介素-1β(IL-1β)和肿瘤坏死因子(TNF-α)活性含量和IL-1β和TNF-αmRNA表达等。结果在含水量方面、在离子含量方面、在IL-1β和TNF-α含量方面以及在IL-1β和TNF-αmRNA表达方面,局灶低温(25℃)组与全脑低温组以及脑外伤模型组相比均呈现不同程度的变化。结论局灶低温(25℃)治疗能明显减轻脑水肿;全脑低温治疗加重脑水肿;其机制之一可能是通过抑制或促进炎性因子IL-1β、TNF-α表达而起作用。     

缺氧预处理对创伤性脑损伤大鼠 Claudin5 表达及血脑屏障通透性的影响

目的探讨缺氧预处理对创伤性脑损伤大鼠脑组织紧密连接蛋白Claudin-5的表达及血-脑屏障通透性的影响。方法204只大鼠随机分为创伤性脑损伤组（T组）96例,缺氧预处理后脑损伤组（H组）96例及对照组12例。T组行自由落体撞击法建立大鼠创伤性脑损伤模型,H组给予3d缺氧预处理后,同法致脑损伤,两组大鼠于伤后1h、4h、8h、12h、24h、3d、7d、14d断头处死。采用干湿重法测脑组织含水量：Real—timePCR和Westernblot检测各组大鼠挫伤区周围脑组织Claudin-5mRNA及蛋白表达变化;IgG法检测血一脑屏障通透性变化。结果T组和H组伤后1hClaudin-5mRNA及蛋白表达开始降低,8～12h降至最低点,1d开始上升,直至伤后14d渐趋于对照组水平;其中H组各时间点Claudin-5mRNA及蛋白表达均高于T组。T组各时间点血一脑屏障通透性及脑组织含水量均明显高于H组（P〈0．05）,且两组均高于对照组（P〈0．05）。结论缺氧预处理可在创伤性脑损伤早期上调紧密连接蛋白Claudin-5的表达,维持血-脑屏障完整性,减轻脑水肿。     

缺氧预处理对创伤性脑损伤大鼠缺氧诱导因子-1α、葡萄糖转运体3型及神经元核蛋白表达的影响

目的探讨缺氧预处理(HPC)对创伤性脑损伤(TBI)大鼠挫伤灶周围皮层组织中缺氧诱导因子-1α(HIF-1α)、葡萄糖转运体3型(GLUT-3)表达及神经元存活影响。方法 120只Sprague-Dawley大鼠按随机数字法分为对照组(12只)、TBI组(54只)、HPCT组(54只)。TBI组按Feeney自由落体撞击法建立大鼠TBI模型,HPCT组先给予3 d HPC(50.47 k Pa,3 d,3 h/d),之后同法致伤。采用RT-PCR及Western blotting检测伤后1、4、8、12 h及1、3、7、14 d挫伤灶周围HIF-1α、GLUT-3 m RNA及蛋白的表达,并分析HIF-1α与GLUT-3之间的相关性,采用免疫组化检测伤后14 d挫伤灶周围神经元核蛋白(Neu N)阳性表达率来观察神经元存活情况。多组间比较行单因素方差分析,用LSD法行两两比较分析2组间差异,相关性分析用Pearson相关分析,以P0.05为差异具有统计学意义。结果 TBI组伤后4 h至3 d HIF-1α、GLUT-3的表达均明显增加(P0.05)。HPCT组HIF-1α及GLUT-3的表达在伤后1 h即增强,伤后4 h至7 d HIF-1α、GLUT-3表达量和伤后14 d Neu N阳性细胞数均明显高于TBI组,差异均具有统计学意义(P0.05)。相关性分析表明HIF-1α与GLUT-3 m RNA及蛋白的表达均呈正相关。结论 HPC可通过诱导皮层脑组织HIF-1α的表达,上调GLUT-3 m RNA及蛋白的表达,进而提高TBI后急性期神经元的存活率。     

脑出血灶周HIF-1α的表达与脑水肿的实验研究

目的明确脑出血后灶周脑组织不同时间点HIF-1α蛋白的表达规律,在脑水肿的发生、发展过程中的可能作用,相关性及临床意义。方法本研究以不同时间点高血压脑出血患者开颅手术中取的脑出血灶周组织为病例组标本,按发病时间分为<6 h、6~24 h、24 h~3 d、>3 d组。以手术入颅路径上远离血肿处少许破坏的的脑组织做为对照组标本,通过干湿称重法测脑含水量,同时应用免疫组化染色方法,RT-PCR方法观察各组各时间点病灶周围脑组织HIF-1α的表达变化。结果 (1)脑组织水含量的变化,脑出血后脑水肿程度随出血时间的延长逐渐加重,在出血6 h内含水量即开始增高,24 h后较明显增高,3 d左右达到峰值,之后减轻(P<0.05)。(2)脑出血血肿灶周组织中HIF-1α圴有表达,对照组与出血组相比均有显著性意义(P<0.05),且出血组各时间点间比较均有差异(P<0.05)。出血6 h后免疫阳性细胞数开始增加,24 h~3 d组阳性细胞数最多,之后逐渐下降。HIF-1α与脑水肿成正相关。结论 (1)脑出血灶周HIF-1α的表达明显升高,与脑水肿密切相关。(2)HIF-1α的异常表达在高血压脑出血后脑水肿中起重要作用,促进脑水肿的发生,为脑出血的治疗提供新的靶点。     

高压氧对颅脑损伤大鼠脑组织水通道蛋白-4表达的影响

目的 通过研究高压氧治疗对颅脑损伤大鼠脑组织水通道蛋白-4(AQP-4)表达与脑水肿的影响,探讨高压氧治疗颅脑损伤的可能作用机制. 方法 将雄性SD大鼠按随机数字表法分成3组,即假手术组、外伤对照组和高压氧治疗组,其中外伤对照组和高压氧治疗组均分为致伤后12h、1 d、3d及5 d4组.采用自由落体法制作颅脑损伤模型.干湿比重法测定脑组织的含水量,免疫组化法测定AQP-4的表达.结果 高压氧治疗组脑组织含水量较外伤对照组明显减少,但较假手术组增多,比较差异均有统计学意义(P<0.05).AQP-4在各组大鼠脑组织中均有表达,假手术组呈低表达;颅脑损伤后12 h伤灶周围水肿区星形胶质细胞足突AOP-4表达开始增高,1 d达到高峰,3 d后降低;高压氧组治疗大鼠各时间点伤灶周围AQP-4的表达与外伤对照组相比明显减低,差异具有统计学意义(P<0.05).结论 高压氧治疗可能通过AQP-4表达的减少来减轻脑水肿的发生,从而保护病灶周围脑组织.     

ICAM-1在大鼠弥漫性脑损伤后的脑组织水肿中的表达及其意义

目的探讨ICAM-1在大鼠弥漫性脑损伤后脑水肿中的作用。方法采用Marmarou等人的方法建立大鼠弥漫性脑损伤模型,S-P免疫组化法测定ICAM-1蛋白在外伤后不同时间脑组织中的表达,干湿重法测脑组织含水量,组织切片HE染色观测炎性细胞浸润情况。结果伤后6h,脑组织中ICAM-1蛋白表达明显升高,72h达到高峰,其后下降,7d时仍明显高于假手术对照组(P<0.05)。伤后6h、12h、24h、48h、72h和7d时,脑组织含水量亦明显高于假手术组(P<0.05),同时伤后脑组织中炎性细胞大量聚集。结论大鼠脑外伤诱导了ICAM-1蛋白的表达,ICAM-1通过介导炎性细胞的浸润可能参与了伤后脑水肿的形成过程。     

吡格列酮对大鼠创份性脑损伤后炎症因子抑制作用的研究

目的 探讨过氧化物酶体增殖物激活受体-γ(PPAR-γ)及其激活剂噻唑烷二酮类药物--吡格列酮对创伤性脑损伤(TBI)大鼠模型脑组织中正常T细胞活化后表达和分泌的调节蛋白(RANTES)、巨噬细胞移动抑制因子(MIF)表达的影响. 方法成年SD大鼠按照随机数字表法分为正常对照组(10只)、假手术组(10只)、TBI模型组(12只)及吡格列酮治疗组(12只).后两组采用改进的Feeney自由落体脑损伤装置制作TBI大鼠模型.伤后18 h分别给予生理盐水及20mg/(kg·d)吡格列酮治疗:假手术组不进行自由落体致伤,其余步骤同上,术后给与生理盐水治疗;正常对照组不进行任何处理.7 d后收集各组大鼠脑组织,计算脑组织含水量,并采用RT-PCR及Westernblot法检测各组PPAR-γ、RANTES及MIF的mRNA、蛋白表达差异. 结果与对照组及假手术组相比,TBI损伤组大鼠脑组织含水量明显增加,且PPAR-γmRNA表达明显增强,同时RANTES、MIF mRNA及蛋白表达也明显上调;而吡格列酮治疗组大鼠脑组织PPAR-γ的表达进一步增加,RANTES及MIF表达则有所下降. 结论吡格列酮对减轻创伤性脑损伤后持续存在的炎症反应及脑水肿具有一定作用,其机制可能与降低脑组织中RANTES及MIF等炎性细胞因子含量有关.     

颅脑损伤大鼠皮质HIF-1α和GLUT-3的表达及意义

目的探讨颅脑损伤(traumatic brain injury,TBI)大鼠皮质脑组织缺氧诱导因子-1α(HIF-1α)和葡萄糖转运蛋白-3(GLUT-3)的表达变化,并进行相关性研究。方法 108只SD大鼠随机分为正常对照组(n=12)和实验组(n=96)。实验组采用自由落体打击法建立大鼠颅脑损伤模型,正常对照组不做处理。分别采用RT-PCR及免疫组化检测伤后1、4、8、12 h及1、3、7、14 d挫伤灶周围HIF-1α和GLUT-3 m RNA及蛋白的表达。结果 RT-PCR结果显示:实验组HIF-1α和GLUT-3 m RNA在伤后4 h升高,12 h达高峰,7 d基本正常;伤后4 h~3 d与正常对照组比较,差异均有统计学意义(P0.05)。Western blot检测显示:实验组HIF-1α和GLUT-3蛋白在伤后4 h表达升高,1 d达高峰,7 d降至正常水平;伤后4 h~3 d与正常对照组差异均有统计学意义(P0.05)。相关性分析表明:HIF-1α与GLUT-3在m RNA及蛋白水平均呈正相关(r=0.894,P0.05;r=0.921,P0.05)。结论 TBI后脑组织HIF-1αm RNA及蛋白的表达上调,可能介导GLUT-3的表达增加,从而发挥神经保护作用。     

VEGF-165基因对创伤性脑损伤脑血流动力学影响的实验研究

目的 研究外源性血管内皮细胞生长因子(VEGF)基因治疗大鼠创伤性脑损伤(TBI)后脑灌注的变化,了解其血流动力学改变.方法 创伤性脑损伤大鼠模型建立后随机分为3组:治疗组,质粒对照组,外伤组.通过RT-PCR检测脑伤后1h、6h、24h、3d、7d、14 d VEGF mRNA在损伤局部的表达改变;应用CT灌注像(CTP)研究不同时间脑血流量(CBF)、脑血容量(CBV)等参数在VEGF-165基因治疗前后的动态变化.结果 VEGF-165基因治疗创伤性脑损伤大鼠后经RT-PCR扩增的VEGF mRNA绝对积分光密度值水平显著高于外伤组和质粒对照组(P＜0.05).CTP参数和伪彩图均显示基因治疗组脑灌注在伤后24h CBF、CBV有增高趋势,伤后3d、7d脑灌注明显高于TBI 组(P＜0.05),虽然伤后14 d CBF、CBV开始降低,但和TBI组比较仍然较高.结论 本研究结果显示大鼠创伤性脑损伤后外源性VEGF基因能够提高脑损伤组织的脑灌注,改善脑损伤部位微循环,为损伤组织的恢复提供基础.     

磁共振成像评估丁苯酞软胶囊对创伤性脑水肿大鼠的治疗作用

目的运用磁共振成像探索大鼠创伤性脑水肿的演变规律及丁苯酞软胶囊对其的治疗作用。方法 SD雄性大鼠175只。随机分为非干预组、干预组和正常对照组。采用Marmarou法制作创伤性脑水肿大鼠模型,造模成功后分别于6 h、12 h、1 d、3 d、7 d行磁共振成像扫描、HE染色、脑组织含水量测定、伊文思蓝渗出量测定。结果磁共振成像、HE染色、和脑组织含水量测定结果提示与对照组相比,非干预组和干预组脑组织可见明显脑水肿,其中以损伤后24 h最明显,3 d后开始减轻。干预组较非干预组脑水肿程度明显减轻。伊文思蓝渗出检测提示,创伤性脑损伤后伊文思蓝渗出量增多,其中以6 h渗出量最多。非干预组较干预组渗出明显。结论创伤性脑损伤后,继发血管源性脑水肿和细胞毒性脑水肿,其中以1 d时脑水肿最明显,丁苯酞软胶囊能明显减轻脑损伤后脑水肿的形成。     

缺氧预处理对颅脑损伤大鼠脑组织HIF-1α及其HO-1表达的影响

目的探讨缺氧预处理对颅脑损伤大鼠脑组织缺氧诱导因子（HIF-1α）及血红素氧合酶-1（HO-1）表达的影响。方法 Sprague-Dawley大鼠102只,随机分为对照组（n=6）、创伤组（n=48）和预处理组（n=48）。创伤组按照改进的Feeney自由落体撞击法建立大鼠颅脑损伤模型,预处理组给予缺氧预处理后,同法造模。采用RT-PCR和Western blotting观察伤后1 h、4 h、8 h、12 h和1 d、3 d、7 d、14 d挫伤周围脑组织HIF-1α、HO-1表达变化。结果创伤组与对照组比较,HIF-1α和HO-1在伤后4 h、8 h、12 h和1、3 d表达上调（P〈0.05）。预处理组与创伤组比较,HIF-1α和HO-1在伤后1 h逐渐上调,伤后4 h、8 h、12 h和1、3 d表达显著上调,直至伤后7 d（P〈0.05）。结论缺氧预处理可增加颅脑损伤后挫伤区周围脑组织HIF-1α的表达,进而促进HO-1 m RNA及蛋白表达。其机制可能是缺氧预处理提高颅脑损伤对缺氧的适应性,减轻挫伤周围脑组织氧自由基对神经细胞伤害。     

Glycerol accumulation in edema formation following diffuse traumatic brain injury

Traumatic brain injury (TBI) induces brain edema via water and glycerol transport channels, called aquaporins (AQPs). The passage of glycerol across brain cellular compartments has been shown during edema. Using a modified impact/head acceleration rodent model of diffuse TBI, we assessed the role of hypoxia inducible factor (HIF)-1alpha in regulating AQP9 expression and glycerol accumulation during the edema formation. Adult (400-425 g) male Sprague-Dawley rats received a closed head injury with a weight drop (450 g, 2-m height) and were allowed to survive up to 48 hours. Some rat groups were administered 2-methoxyestradiol (2ME2, a HIF-1alpha inhibitor) 30 minutes after injury and were euthanized at 4 and 24 hours after injury. Brain edema was measured directly by water content, and glycerol concentration was determined by the Cayman Glycerol Assay. HIF-1alpha and AQP9 protein levels were assessed by Western immunoblotting. This study demonstrated a significant (P<0·05) increase in brain water content at 4-48 hours following impact. Cerebral glycerol was significantly (P<0.05) up-regulated at as early as 1 hour and remained at high levels for up to 48 hours. Similarly, significant (P<0.05) increases in HIF-1alpha and AQP9 protein levels were found at 1 hour and up to 48 hours after injury. Compared to untreated but injured rats, inhibition of HIF-1alpha by 2ME2 significantly (P<0.05) reduced the TBI-induced AQP9 up-regulation. This reduction was temporally associated with significant (P<0.05) decreases in both edema and glycerol accumulation. The data suggested an associated induction of HIF-1alpha, AQP9, and extracellular glycerol accumulation in edema formation following diffuse TBI. The implication of HIF-1alpha and AQP9 underlying TBI-induced edema formation offers possibilities for novel TBI therapies.     

促红细胞生成素对颅脑创伤后炎性反应和细胞凋亡的影响

目的 探讨重组人促红细胞生成素(rhEPO)对大鼠创伤性脑损伤后(TBI)脑组织核因子NF-κB的表达、下游炎性因子水平及皮层神经细胞凋亡的调控作用.方法 72只Wistar大鼠随机分成对照组、TBI组、TBI+rhEPO组,后两组再分为脑损伤后1 d、3 d、7 d亚组,应用EMSA法检测挫伤灶周围脑组织NF-κB结合活性、ELISA法检测炎性因子TNF-α、IL-6水平、干湿比重法检测脑组织水含量、TUNEL法检测皮层神经细胞凋亡.结果 TBI后脑组织中NF-κB结合活性、炎性因子水平持续升高;伤后脑水肿明显;TUNEL阳性细胞显著增多.给予rhEPO治疗后,脑组织NF-κB结合活性、TNF-α、IL-6水平、伤侧脑组织水肿程度及神经细胞凋亡均比TBI组降低(P＜O.01).结论 rhEPO能够抑制TBI后脑组织NF-κB的结合活性、降低下游炎性因子的表达和脑水肿程度、减少神经细胞凋亡,明显减轻继发性脑损害.

Abstract：

Objective To investigate the role of rhEPO in regulating expression of nuclear factor -kappaB (NF - κB) , proinflammatory cytokines and neural apoptosis in the injured brain following traumatic brain injury. Methods A total of 72 Wistar rats were randomly divided into control group, trauma group and rhEPO treatment group. TBI group and rhEPO group sacrificed at days 1, 3 and 7 post injury respectively. Activity of NF - κB in the brain tissues were detected by using EMSA and levels of TNF - αand IL - 6 by ELISA. The water content of the injured brain was measured by dry - wet weight method. Furthermore, apoptosis in the cortical contusion was estimated by TUNEL method. Result The result showed a persistent up - regulation of NF - κB binding activity, expression of TNF -α,IL -6 in the area surrounding the injuried brain and significant brain edema. The TUNEL positive cells significantly increased. The level of NF - κB binding activity and inflammatory factors expression, the water content of the injury brain and apoptosis can be significantly decreased by administration of rhEPO ( P ＜ 0.01). Conclusion rhEPO administration can inhibit the binding activity of the NF - κB, down - regulate the expression of the inflammatory factors, alleviate the brain edema and apoptosis and decrease the secondary brain injury after TBI.     

局灶性脑低温处理对大鼠创伤性脑损伤模型的保护作用

目的探讨局灶性低温处理对SD大鼠创伤性脑损伤（TBI）模型的保护作用并探讨其相关机制。 方法将15只雄性SD大鼠随机平均分成假手术组（sham）,非冷却组（non-cooling）和冷却组（cooling）。Non-cooling组和cooling组制作TBI模型,3组实验同步进行,创伤后低温处理3 h,复温3 h,过程中检测大鼠血气、皮层脑电。复温结束处死大鼠后,对脑组织进行TTC和HE染色以评价脑死亡和脑水肿情况,Western blot检测相关机制蛋白表达情况。 结果Sham组和non-cooling组受外部刺激脑组织代谢升高,cooling组较其他组脑组织代谢低,TTC和HE染色显示cooling组脑死亡的面积和细胞死亡数量均少于non-cooling组,差异均具有统计学意义（P<0.05）。大鼠TBI后局灶性低温处理能显著降低大脑皮层的癫痫样棘波,在回温时这种不完全抑制持续存在,且低温处理降低了GABA_B1R蛋白的表达,差异均具有统计学意义（P<0.05）。Cooling组的脑水肿情况较non-cooling组轻,且cooling组AQP4蛋白表达降低,差异均具有统计学意义（P<0.05）。 结论局灶性低温处理对TBI大鼠具有保护作用,能显著减轻TBI引起的脑水肿,抑制大脑皮层的癫痫样棘波,具体机制可能分别与GABA_B1R和AQP4相关。为临床治疗TBI提供了一种更加安全、简单有效的方法。     

盐酸纳美芬对大鼠颅脑损伤后脑水肿的影响

目的探讨盐酸纳美芬对大鼠颅脑损伤后脑水肿的影响。方法将54只Wistar大鼠按随机数字表法随机分为假手术组、颅脑损伤组及纳美芬治疗组。采用自由落体法建立大鼠颅脑损伤模型,分别于伤后6 h、1 d、3 d、7 d,采用干湿重法检测脑组织含水量,应用免疫组织化学法检测损伤脑组织中水通道蛋白4（AQP4）的表达。结果与假手术组比较,颅脑损伤组和纳美芬治疗组的脑组织含水量及AQP4水平明显升高（P〈0.05）;与颅脑损伤组相比,纳美芬治疗组脑组织含水量及AQP4表达水平明显降低（P〈0.05）。通过相关性分析发现,大鼠颅脑损伤后脑组织AQP4表达水平与脑含水量呈明显正相关性（r=0.676,P〈0.01）。结论盐酸纳美芬可能通过抑制AQP4表达,减轻脑水肿,发挥神经保护作用。     

Postinjury administration of L-deprenyl improves cognitive function and enhances neuroplasticity after traumatic brain injury

The rat model of combined central fluid percussion traumatic brain injury (TBI) and bilateral entorhinal cortical lesion (BEC) produces profound, persistent cognitive deficits, sequelae associated with human TBI. In contrast to percussive TBI alone, this combined injury induces maladaptive hippocampal plasticity. Recent reports suggest a potential role for dopamine in CNS plasticity after trauma. We have examined the effect of the dopamine enhancer l-deprenyl on cognitive function and neuroplasticity following TBI. Rats received fluid percussion TBI, BEC alone, or combined TBI + BEC lesion and were treated once daily for 7 days with l-deprenyl, beginning 24 h after TBI alone and 15 min after BEC or TBI + BEC. Postinjury motor assessment showed no effect of l-deprenyl treatment. Cognitive performance was assessed on days 11-15 postinjury and brains from the same cases examined for dopamine beta-hydroxylase immunoreactivity (DBH-IR) and acetylcholinesterase (AChE) histochemistry. Significant cognitive improvement relative to untreated injured cases was observed in both TBI groups following l-deprenyl treatment; however, no drug effects were seen with BEC alone. l-Deprenyl attenuated injury-induced loss in DBH-IR over CA1 and CA3 after TBI alone. However, after combined TBI + BEC, l-deprenyl was only effective in protecting CA1 DBH-IR. AChE histostaining in CA3 was significantly elevated with l-deprenyl in both injury models. After TBI + BEC, l-deprenyl also increased AChE in the dentate molecular layer relative to untreated injured cases. These results suggest that dopaminergic/noradrenergic enhancement facilitates cognitive recovery after brain injury and that noradrenergic fiber integrity is correlated with enhanced synaptic plasticity in the injured hippocampus.     

高压氧治疗大鼠脑外伤后脑组织NF-κB(P50)表达的实验研究

目的 探讨高压氧对颅脑外伤的治疗作用及与脑组织中NF-κB(P50)表达之间的关系. 方法 120只SD大鼠按随机数字表法分为假手术组(仅开颅钻孔,不行打击)、外伤对照组(Feeney自由落体损伤模型制作法制造中度大鼠脑外伤模型,但不接受氧治疗)、常压氧治疗组(脑外伤模型制作成功后立即接受正常压力下纯氧吸入治疗)、高压氧治疗组(脑外伤模型制作成功后立即接受0.2 MPa压力下高压氧治疗),并于伤后6h、1 d、3 d、5 d、7 d五个时相点断头法取脑组织(每时相点6只),光镜下观察脑组织损伤水肿的病理变化以及采用免疫组化方法检测NF-κB(P50)在脑组织中的表达情况. 结果 高压氧干预使相同时相点高压氧治疗组大鼠脑水肿情况及损伤程度较外伤对照组明显减轻,而常压氧干预作用则不明显.假手术组各时相点仅见微量的NF-κB(P50)阳性表达或不表达,其他各组脑损伤后6 h即发现损伤脑组织内NF-κB(P50)阳性表达上调,且持续呈增高趋势,伤后5 d时达到最高值.高压氧治疗组与外伤对照组及常压氧治疗组相比在相同时相点NF-κB(P50)表达均有增强,差异有统计学意义(P<0.05). 结论 高压氧治疗对损伤神经细胞具有保护、修复的治疗作用,增加NF-κB(P50)在脑组织细胞中的表达可能是其神经保护途径之一.     

电刺激预处理对大鼠颅脑创伤后认知功能的影响

目的探讨非创伤性(电刺激)动员外周血内皮祖细胞对大鼠颅脑创伤后认知功能的影响及其可能机制。方法于电刺激后24h对成年雄性Wistar大鼠施行液压打击术,制备颅脑创伤模型,流式细胞术测量创伤后外周血内皮祖细胞数量;免疫组织化学染色观察患侧海马区血管性血友病因子表达阳性(vwF~+)微血管密度;Morris水迷宫实验评价大鼠伤后认知功能恢复程度。结果与单纯打击组比较,创伤后3h和6h电刺激预处理组大鼠外周血内皮祖细胞数量显著升高(均P=0.000),之后逐渐降至正常水平;与其他各组相比,伤后第1天电刺激预处理组大鼠海马区vWF~+微血管密度即开始增加,至第7天达高峰平台期(P=0.000);与单纯打击组相比,Morris水迷宫实验训练第3天时电刺激预处理组大鼠逃避潜伏期开始缩短,随着训练时间的延长,组间差异明显增加且具有统计学意义(P=0.016)。结论电刺激预处理可促进颅脑创伤后认知功能的恢复。其潜在的机制可能与创伤前动员机体外周血内皮祖细胞,使得伤后更多的内皮祖细胞归巢到损伤区域,有助于伤后血管新生和神经功能的恢复。     

电刺激预处理对大鼠颅脑创伤后认知功能的影响

目的探讨非创伤性（电刺激）动员外周血内皮祖细胞对大鼠颅脑创伤后认知功能的影响及其可能机制。方法于电刺激后24h对成年雄性Wistar大鼠施行液压打击术,制备颅脑创伤模型,流式细胞术测量创伤后外周血内皮祖细胞数量;免疫组织化学染色观察患侧海马区血管性血友病因子表达阳性（vwF）微血管密度;Morris水迷宫实验评价大鼠伤后认知功能恢复程度。结果与单纯打击组比较,创伤后3h和6h电刺激预处理组大鼠外周血内皮祖细胞数量显著升高（均P=0．000）,之后逐渐降至正常水平;与其他各组相比,伤后第1天电刺激预处理组大鼠海马区vWF微血管密度即开始增加,至第7天达高峰平台期（P=0．000）;与单纯打击组相比,Morris水迷宫实验训练第3天时电刺激预处理组大鼠逃避潜伏期开始缩短,随着训练时间的延长,组间差异明显增加且具有统计学意义（P=0．016）。结论电刺激预处理可促进颅脑创伤后认知功能的恢复。其潜在的机制可能与创伤前动员机体外周血内皮祖细胞,使得伤后更多的内皮祖细胞归巢到损伤区域,有助于伤后血管新生和神经功能的恢复。     

Concomitant upregulation of nuclear factor-kB activity, proinflammatory cytokines and ICAM-1 in the injured brain after cortical contusion trauma in a rat model

BACKGROUND: Nuclear factor kappa B (NF-kB), proinflammatory cytokines and intercellular adhesion molecule 1 (ICAM-1) are frequently upregulated in the injured brain after traumatic brain injury (TBI). However, the temporal pattern of upregulation is not well defined. AIMS: The current study was undertaken to investigate the temporal profile of the expression of NF-kB, proinflammatory cytokines and ICAM-1 in the injured brain after cortical contusion trauma of the rat brain. SETTINGS AND DESIGN: A rat model of cortical contusion was produced by a free-falling weight on the exposed dura of right parietal lobe. The rats were randomly divided into control group and TBI groups at hours 3, 12, 24 and 72, and on day 7. MATERIAL AND METHODS: NF-kB binding activity in the surrounding brain of injured area was studied by electrophoretic mobility shift assay (EMSA). The levels of TNF-alpha and IL-6 were detected using ELISA and ICAM-1 expression studied by immunohistochemistry. STATISTICAL ANALYSIS: The data were analyzed by one-way ANOVA followed by Student-Newman-Keuls post hoc test. Relation between variables was analyzed using bivariate correlation with two-tailed test. RESULTS: Compared with that of control group, NF-kB binding activity in the injured brain was significantly increased through 12 h and 7 days postinjury, with the maximum at 72 h. The concentrations of TNF-alpha and IL-6 in the injured brain were significantly increased from 3 h to 7 days and maximal at 24 h postinjury. The number of ICAM-1 immunostained microvessels was significantly increased in the injured brain from 24 h to 7 days postinjury, with its peak at 72 h. Concomitant upregulation of TNF-alpha, IL-6, ICAM-1 and the cytokine mediators NF-kB in the injured brain was observed in the injured brain after cortical contusion, and there was a highly positive relation among these variables. CONCLUSIONS: Cortical contusion trauma could induce a concomitant and persistent upregulation of NF-kB binding activity, TNF-alpha, IL-6 and ICAM-1 in the injured rat brain which might play a central role in the injury-induced immune response of brain.