川芎嗪对慢性脑缺血小鼠认知功能障碍及海马星形胶质细胞胶质原纤维蛋白表达的影响

目的探讨川芎嗪(tetramethylpyrazine,TMP)对慢性脑缺血小鼠认知功能障碍及海马星形胶质细胞胶质原纤维蛋白(glial fibrillary acidic protein,GFAP)表达的影响。方法采用改良双侧颈总动脉结扎术建立小鼠慢性脑缺血模型,经腹腔分别注射30和80 mg/kg的TMP注射液(即TMP低、高剂量组),每组10只,另设假手术组(不结扎),模型组和假手术组腹腔注射等量生理盐水。各组均在术后24 h开始给药,每日1次,连续8周。Morris水迷宫试验检测小鼠空间学习和记忆能力;黄嘌呤氧化酶法检测小鼠海马组织中的超氧化物歧化酶(superoxidedismutase,SOD)含量,硫代巴比妥酸(TBA)法检测丙二醛(malonaldehyde,MDA)含量,双抗体两步ELISA法检测肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)及白介素-1β(interleukin-1β,IL-1β)含量;免疫组织化学染色法及Western blot法检测小鼠海马CA1区GFAP的表达水平。结果与模型组比较,TMP低、高剂量组小鼠在Morris水迷宫定位航行试验中的逃避潜伏期和游泳路程均明显缩短(P<0.05),空间探索试验中穿越原平台的次数增多(P<0.05);小鼠海马组织中SOD含量明显增加(P<0.05),MDA、TNF-α及IL-1β含量明显降低(P<0.05);IOD值明显下降(P<0.05),GFAP表达水平明显下降(P<0.05)。结论 TMP可改善慢性脑缺血小鼠认知功能障碍,其机制可能是增强抗脂质氧化能力,抑制星形胶质细胞增生活化,减少GFAP的表达,减轻炎症反应,从而降低对海马组织的损害。     

糖尿病大鼠脑缺血再灌注海马CA1区Fas蛋白的表达

目的观察糖尿病大鼠脑缺血再灌注海马CA1区病理变化及Fas蛋白的表达。方法采用链脲佐菌素(STZ)诱导和线栓法建立糖尿病大鼠大脑中动脉闭塞模型,应用HE染色和免疫组化方法,比较糖尿病大鼠脑缺血再灌注组与缺血再灌注组海马CA1区神经元损伤程度及Fas蛋白表达变化。结果糖尿病大鼠脑缺血再灌注组海马CA1区神经元缺失,且Fas蛋白表达上调,明显高于缺血再灌注组。结论糖尿病大鼠脑缺血再灌注损伤后,海马CA1区神经元发生严重缺失,Fas介导的细胞凋亡机制可能是糖尿病加重脑缺血再灌注海马区神经元损伤的机制之一。     

红藻氨酸致痫大鼠海马小窝蛋白(Cav-1)和核因子(NF-κB)的变化及灵芝多糖的干预

观察灵芝多糖(GLP)对于红藻氨酸(kainicacidKA)致痫大鼠海马Cav-1和NF-κB的影响。方法:将60只健康雄性Wistar大鼠随机分成正常对照组、假手术组、癫痫模型组、灵芝多糖治疗低浓度组、灵芝多糖治疗中浓度组、灵芝多糖治疗高浓度组每组10只。采用激光共聚焦方法计数各组海马Cav-1和NF-κB阳性细胞的数量。结果:癫痫模型组Cav-1阳性细胞数明显高于正常对照组;灵芝多糖治疗组Cav-1阳性细胞数高于癫痫模型组;NF-κB阳性细胞数癫痫模型组明显高于正常对照组;灵芝多糖治疗各组NF-κB阳性细胞数低于癫痫模型组。同时,高、中浓度组之间Cav-1和NF-κB蛋白光密度未见明显异常。结论:灵芝多糖能增强大鼠海马神经元Cav-1表达和抑制NF-κB的表达,减轻海马神经元的变性、坏死和凋亡,起到抗癫痫作用。     

脑红蛋白在内毒素脑损伤过程中的表达上调

目的探讨内毒素脑损伤模型大鼠的额叶皮质、海马组织、脑脊液(CSF)和血浆中脑红蛋白(NGB)的表达变化及其意义。方法将SD大鼠随机分为内毒素干预组和对照组,内毒素干预组向大鼠第四脑室内注射内毒素0.1mg/kg,对照组注入等剂量的生理盐水。于注射后3、6、12、24、48和72h采血,分离血清,收集CSF,并处死大鼠,留取额叶皮质和海马组织,应用ELISA、Western blot检测NGB含量,免疫组织化学法检测NGB的表达,干燥法检测鼠脑含水量。结果注射6h后,内毒素干扰组鼠脑含水量明显高于对照组,48h达峰值;额叶皮质、海马组织、CSF和血浆中NGB含量显著高于对照组,48h达峰值。结论在内毒素所致脑损伤中,NGB表达上调,且与内毒素的注入时间相关,NGB表达上调是机体内源性神经保护机制之一。     

大鼠颅脑损伤后神经细胞的凋亡

目的观察大鼠颅脑损伤后不同时间损伤周边区额皮质及海马CA1区神经细胞的凋亡现象,为颅脑外伤的临床治疗提供理论依据。方法将SD大鼠分为正常对照组(30只)、假手术对照组(30只)和损伤组(80只),采用侧位液压冲击法制成颅脑损伤动物模型,损伤组按冲击时脑组织所承受力量大小,进一步分为轻、中、重度3组,采用免疫组织化学技术和原位末端标记法(TUNEL)检测各组大鼠损伤后4、8、24、72、96h和7d大鼠伤灶周边额皮质及海马CA1区的凋亡细胞。结果轻、中、重度损伤组大鼠损伤区周边额皮质和海马CA1区各时间点凋亡阳性细胞数均高于正常对照组和假手术对照组,重度损伤组高于轻度和中度损伤组,且差异均有统计学意义。损伤4h后,各损伤组伤灶边缘额皮质和海马CA1区开始出现凋亡细胞,随后逐渐增加,分别于72和24h达高峰,之后开始下降。结论颅脑损伤可导致损伤周边区大脑额皮质及海马CA1区神经细胞凋亡,凋亡高峰时间分别为损伤后72和24h。     

迷走神经刺激对癫痫大鼠海马缝隙连接蛋白43表达的影响

目的观察迷走神经刺激(vagus nerve stimulation,VNS)对海人酸(kainic acid,KA)致癫痫大鼠海马星形胶质细胞缝隙连接蛋白43(Connexin 43,Cx43)表达的影响,探讨Cx43与癫痫之间的关系及其在VNS治疗癫痫中的作用。方法将SD大鼠随机分为对照组、KA组和VNS+KA组,每组10只;KA组和VNS+KA组大鼠左侧脑室注射3μl 0.05%KA溶液,制备癫痫模型,对照组注射等量生理盐水;VNS+KA组行VNS。观察各组大鼠行为变化,记录皮层脑电图(electrocorticogram,ECoG);采用免疫组织化学法和Western blot法检测各组大鼠海马星形胶质细胞Cx43的表达。结果大鼠左侧脑室注射KA 3⁵ min后,KA组大鼠为RacineⅣ5 min后,KA组大鼠为RacineⅣ^Ⅴ级重型癫痫发作,脑电图可见棘波、棘慢波及簇状高尖波等异常脑电发放;VNS+KA组大鼠为RacineⅠⅤ级重型癫痫发作,脑电图可见棘波、棘慢波及簇状高尖波等异常脑电发放;VNS+KA组大鼠为RacineⅠ^Ⅲ级轻型发作,脑电发放较KA组减轻,对照组无癫痫发作及异常脑电发放。KA组大鼠海马Cx43阳性细胞数和相对表达量均明显高于对照组和VNS+KA组(P均<0.01)。结论癫痫大鼠海马Cx43的表达与癫痫发病机制密切相关,VNS可降低癫痫大鼠海马Cx43的表达,抑制癫痫发作。     

左旋卡尼汀对大鼠缺血心肌细胞凋亡相关蛋白表达的影响

目的观察左旋卡尼汀对大鼠缺血心肌细胞凋亡相关蛋白Bcl-2和Caspase-3表达的影响。方法将SD大鼠随机分成3组:空白对照组、缺血组和左旋卡尼汀组。缺血组及左旋卡尼汀组给予异丙肾上腺素建立心肌缺血模型,左旋卡尼汀组提前经腹腔注射左旋卡尼汀。原位末端标记(TUNEL)法测定凋亡的心肌细胞,免疫组化法测定Bcl-2及Caspase-3蛋白的表达。结果左旋卡尼汀组与缺血组相比,心肌组织Bcl-2蛋白表达率显著升高,细胞凋亡率和Caspase-3蛋白表达率显著降低。结论左旋卡尼汀在异丙肾上腺素所致的心肌缺血大鼠模型中,对缺血缺氧心肌有保护作用,其机制可能是通过调节Bcl-2和Cas-pase-3介导的细胞凋亡而实现的。     

老龄大鼠慢性脑灌注不足行为学观察

目的观察老龄大鼠双侧颈总动脉结扎后行为学变化。方法将大鼠随机分成手术组及对照组,手术组制作慢性脑灌注不足大鼠模型,第1、3、5d对两组进行卒中指数评分、自发性活动测定;第1、4、8、12周进行Morris水迷宫实验和攀绳肌力实验。结果卒中指数和自发性活动测定,手术组第1d与对照组相比有显著差异,第3,5d相比无差异。在Morris水迷宫实验中,手术组在术后第8周及12周与对照组相比,学习记忆功能显著下降,术后12周内大鼠攀绳能力与对照组无显著性差异。结论慢性脑灌注模型对大鼠学习记忆能力具有永久性的损伤作用,而对运动功能无显著性影响。因此,双侧颈总动脉永久性结扎是研究认知功能的良好模型。     

Arc基因表达及甲基化与幼龄鼠和成年鼠空间记忆形成的相关性

目的探讨Arc基因表达及甲基化与幼龄鼠和成年鼠空间记忆形成的相关性。方法应用Morris水迷宫对2月龄幼龄鼠和6月龄成年鼠进行定位航行训练,以判断其空间记忆形成情况。采用RT-PCR检测定位航行训练后大鼠海马组织Arc基因mRNA的转录水平,并对海马基因组DNA进行亚硫酸盐处理,采用甲基化特异性聚合酶链反应(Methylation specific polymerase chain reaction,MS-PCR)检测Arc基因的甲基化情况,并进行DNA甲基化序列分析。结果随着定位航行训练入水次序及训练天数的增加,幼龄鼠逃避潜伏期缩短(P<0.05);而成年鼠在训练当天随着入水次序的增加,逃避潜伏期缩短,但第2天逃避潜伏期不仅与入水次序有关,也随着放入点距离的增大,逃避潜伏期相对延长(P<0.05),至第3天逃避潜伏期与入水次序及距离均无关,形成稳定的记忆能力。成年鼠定位航行训练组海马组织Arc基因mRNA的转录水平显著高于正常对照组(P<0.01),且高于幼龄鼠(P<0.05)。与幼龄鼠正常对照组相比,幼龄鼠和成年鼠定位航行训练组第8和24位点均无甲基化,成年鼠定位航行训练组与正常对照组相比,甲基化位点无变化。结论幼龄鼠瞬时记忆能力接近成年鼠,但形成稳定记忆的能力弱于成年鼠。Arc启动子甲基化影响其mRNA的表达,而Arc基因mRNA的转录水平与大鼠空间记忆能力及年龄相关,进一步证实了甲基化参与调解学习和记忆。     

双歧杆菌介导HSV-tk/GCV系统治疗大鼠膀胱癌的疗效

目的观察双歧杆菌介导的单纯疱疹病毒胸苷激酶(Herpes simplex virus thymidine kinase,HSV-tk)/丙氧鸟苷(Gancyclovir,GCV)系统治疗大鼠膀胱癌的疗效,并初步探讨其可能的作用机制。方法采用N-甲基亚硝基脲(N-methyl-nitrosourea,MNU)膀胱灌注法建立大鼠膀胱癌模型,将模型大鼠随机分为3组,分别经尾静脉注射生理盐水、携带空载体pGEX-5X-1的双歧杆菌和携带重组质粒pGEX-tk的双歧杆菌(含婴儿双歧杆菌4.4×109个/ml),再联合腹腔灌注GCV(50 mg/kg)治疗,治疗结束后称量各组大鼠膀胱重量;TUNEL染色法检测各组大鼠膀胱组织细胞凋亡情况,RT-PCR和Western blot法检测各组大鼠膀胱肿瘤组织细胞色素C(Cyt-C)和半胱氨酸天冬氨酸蛋白酶-9(caspase-9)基因mRNA的转录水平和蛋白的表达水平。结果治疗后,双歧杆菌重组质粒组大鼠膀胱重量明显低于生理盐水对照组和双歧杆菌空载体组(P<0.001),膀胱组织细胞凋亡指数明显高于生理盐水对照组和双歧杆菌空载体组(P<0.001),膀胱肿瘤组织Cyt-C和caspase-9基因mRNA的转录水平和蛋白的表达水平均明显高于生理盐水对照组和双歧杆菌空载体组(P<0.001)。结论双歧杆菌介导的HSV-tk/GCV治疗系统治疗大鼠膀胱癌疗效显著;该治疗系统可能通过以Cyt-C为中心的内源性凋亡途径导致膀胱癌细胞凋亡。     

Neuroprotective Properties of Picroside II in a Rat Model of Focal Cerebral Ischemia

The aim of this study was to explore the effect of picroside II on neuronal apoptosis and the expression of caspase-3 and poly ADP-ribose polymerase (PARP) following middle cerebral artery occlusion/reperfusion in male Wistar rats. Picroside II (10 mg/kg) was administered intravenously into the tail vein of the animals. The neurological function deficits were evaluated with the Bederson's test and the cerebral infarction volume was visualized with tetrazolium chloride (TTC) staining. The apoptotic cells were counted by in situ terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The immunohistochemistry stain and enzyme linked immunosorbent assay (ELISA) was used to determine the expressions of caspase-3 and PARP in brain tissue. The results indicated that rats in the control group showed neurological function deficit and cerebral infarction in ischemic hemisphere after two hours ischemia followed by 22 hours reperfusion. Caspase-3 and PARP expressions were also profound in the cortex, the striatum and the hippocampus, along with increased apoptotic cells in this group. Bederson's score, infarction volume, and expressions of caspase-3 and PARP, as well as apoptosis in the treatment group were, however, significantly decreased compared to those in the control group indicating that intravenous treatment with picroside II might be beneficial to inhibit neuronal apoptosis and, thus, to improve the neurological function of rats upon cerebral ischemia reperfusion injury.     

Primary Study for the Therapeutic Dose and Time Window of Picroside II in Treating Cerebral Ischemic Injury in Rats

The aim of this study was to explore the optimal therapeutic dose and time window of picroside II for treating cerebral ischemic injury in rats according to the orthogonal test. The middle cerebral artery occlusion (MCAO) models were established by intraluminally inserting a thread into middle cerebral artery (MCA) from left external carotid artery (ECA). The successful rat models were randomly divided into 16 groups according to the orthogonal layout of [L(16)(4(5))] and treated by injecting picroside II intraperitoneally with different doses at various times. The neurological behavioral function was evaluated by Bederson's test and the cerebral infarction volume was measured by tetrazolium chloride (TTC) staining. The expressions of neuron specific enolase (NSE) and neuroglial mark-protein S-100 were determined by immunohistochemisty assay. The results indicated that the optimal compositions of the therapeutic dose and time window of picroside II in treating cerebral ischemic injury were ischemia 1.5 h with 20 mg/kg body weight according to Bederson's test, 1.0 h with 20 mg/kg body weight according to cerebral infarction volume, 1.5 h with 20 mg/kg body weight according to the expressions of NSE and S-100 respectively. Based on the principle of the minimization of medication dose and maximization of therapeutic time window, the optimal composition of the therapeutic dose and time window of picroside II in treating cerebral ischemic injury should be achieved by injecting picroside II intraperitoneally with 20 mg/kg body weight at ischemia 1.5 h.     

Neuroprotective Effects of Liraglutide for Stroke Model of Rats

The number of diabetes mellitus (DM) patients is increasing, and stroke is deeply associated with DM. Recently, neuroprotective effects of glucagon-like peptide-1 (GLP-1) are reported. In this study, we explored whether liraglutide, a GLP-1 analogue exerts therapeutic effects on a rat stroke model. Wistar rats received occlusion of the middle cerebral artery for 90 min. At one hour after reperfusion, liraglutide or saline was administered intraperitoneally. Modified Bederson’s test was performed at 1 and 24 h and, subsequently, rats were euthanized for histological investigation. Peripheral blood was obtained for measurement of blood glucose level and evaluation of oxidative stress. Brain tissues were collected to evaluate the level of vascular endothelial growth factor (VEGF). The behavioral scores of liraglutide-treated rats were significantly better than those of control rats. Infarct volumes of liraglutide-treated rats at were reduced, compared with those of control rats. The level of derivatives of reactive oxygen metabolite was lower in liraglutide-treated rats. VEGF level of liraglutide-treated rats in the cortex, but not in the striatum significantly increased, compared to that of control rats. In conclusion, this is the first study to demonstrate neuroprotective effects of liraglutide on cerebral ischemia through anti-oxidative effects and VEGF upregulation.     

神经节苷脂对脑缺血/再灌注损伤的保护作用

目的探讨神经节苷脂对脑缺血再灌注损伤的保护作用。方法采用Ｐｕｌｓｉｎｅｌｌｉ的四血管闭塞法 制作大鼠急性脑缺血／再灌注模型，利用高压液相色谱法观察脑缺血／再灌注期间谷氨酸和γ－氨基丁酸含量的变化， 通过图象分析仪测定神经元的面数密度及神经节苷脂对以上指标的影响。结果缺血后谷氨酸和γ－氨基丁酸含 量明显升高，再灌注后降低，神经节苷脂可降低谷氨酸含量，与盐水对照组相比差异显著（Ｐ＜０．０１），同时增加神经 元面数密度。结论神经节苷脂通过抑制谷氨酸释放，可减轻脑缺血再灌注期间脑组织损伤。     

Pre-Ischemic Treadmill Training for Prevention of Ischemic Brain Injury via Regulation of Glutamate and Its Transporter GLT-1

Pre-ischemic treadmill training exerts cerebral protection in the prevention of cerebral ischemia by alleviating neurotoxicity induced by excessive glutamate release following ischemic stroke. However, the underlying mechanism of this process remains unclear. Cerebral ischemia-reperfusion injury was observed in a rat model after 2 weeks of pre-ischemic treadmill training. Cerebrospinal fluid was collected using the microdialysis sampling method, and the concentration of glutamate was determined every 40 min from the beginning of ischemia to 4 h after reperfusion with high-performance liquid chromatography (HPLC)-fluorescence detection. At 3, 12, 24, and 48 h after ischemia, the expression of the glutamate transporter-1 (GLT-1) protein in brain tissues was determined by Western blot respectively. The effect of pre-ischemic treadmill training on glutamate concentration and GLT-1 expression after cerebral ischemia in rats along with changes in neurobehavioral score and cerebral infarct volume after 24 h ischemia yields critical information necessary to understand the protection mechanism exhibited by pre-ischemic treadmill training. The results demonstrated that pre-ischemic treadmill training up-regulates GLT-1 expression, decreases extracellular glutamate concentration, reduces cerebral infarct volume, and improves neurobehavioral score. Pre-ischemic treadmill training is likely to induce neuroprotection after cerebral ischemia by regulating GLT-1 expression, which results in re-uptake of excessive glutamate.     

白藜芦醇对大鼠脑缺血再灌注氧化应激损伤的影响

目的探讨白藜芦醇(Resveratrol,Res)对大鼠脑缺血再灌注氧化应激损伤的影响。方法将SD大鼠随机分为假手术组(S组)、缺血再灌注组(I/R组,线栓法复制大鼠右侧大脑中动脉栓塞模型)、Res低剂量组(15 mg/kg,I/R+R1组)和Res高剂量组(30 mg/kg,I/R+R2组),于缺血2 h再灌注24 h进行神经功能缺损评分;化学比色法测定大鼠血清和脑组织中丙二醛(Malondialdehyde,MDA)含量及超氧化物歧化酶(Superoxide dismutase,SOD)活性;TTC法测定脑梗死体积;干湿重法测定脑含水量,HE染色观察脑组织的病理改变。结果与I/R组相比,Res能改善大鼠脑缺血再灌注损伤后的神经功能缺失(P<0.01),降低血清及脑组织中MDA的含量(P<0.01),提高SOD活性(P<0.01),缩小脑梗死体积(P<0.01),降低损伤侧脑含水量(P<0.01),改善脑组织的病理变化,且呈剂量依赖性。结论 Res对大鼠局灶性脑缺血再灌注氧化应激损伤具有良好的保护作用,其机制可能与清除自由基,减轻氧化性损伤有关。     

microRNA沉默卡氏肺孢子菌主要表面糖蛋白基因对大鼠卡氏肺孢子菌肺炎的治疗作用

目的探讨靶向卡氏肺孢子菌(Pneumocystis carinii,PC)主要表面糖蛋白基因(Major surface glycoprotein gene,MSG)上游保守序列(Upstream conserved sequence,UCS)的microRNA重组质粒对大鼠卡氏肺孢子菌肺炎(Pneumocystis cariniipneumonia,PCP)的治疗作用。方法将SD大鼠经腹股沟皮下注射地塞米松磷酸钠7周,制备大鼠PCP感染模型。将模型大鼠随机分为5组:microRNA重组质粒治疗组(M组)、磺胺药物治疗组(H组)、生理盐水对照组(C1组)、空载体质粒对照组(C2组)和模型对照组(C3组),其中M组和C1、C2组经尾静脉分别注射含microRNA重组质粒pPC-UCS、生理盐水和空载体,H组用磺胺药物灌胃治疗,C3组不做处理,每日1次,疗程为7 d。1周后吉姆萨染色,油镜下计数大鼠肺组织液印片中PC包囊数;HE染色,光镜观察肺组织病理改变;ELISA法检测大鼠血清中IL-10和IFNγ的表达水平;RT-PCR法检测肺组织中PC MSG-UCSmRNA的表达水平;电镜观察PC的超微结构。结果与C1、C2和C3组相比,M组和H组大鼠肺组织PC包囊数均明显减少(P<0.05),肺组织炎症较轻,大鼠血清IL-10的表达水平均显著降低(P<0.05),而IFNγ的表达水平显著升高(P<0.05),大鼠肺组织PC MSG-UCS mRNA的表达水平均显著降低(P<0.05);电镜观察显示,M组和H组PC包囊表面均出现破损,C1、C2、C3组未发现破损。结论 microRNA重组质粒pPC-UCS对大鼠PCP有明显的治疗作用,为治疗PCP提供了新的思路。