蛛网膜下腔出血后大鼠基底动脉p38MAPK信号传导途径研究

目的探讨蛛网膜下腔出血(SAH)后大鼠基底动脉中p38丝裂原活化蛋白激酶(p38MAPK)信号传导通路的活化情况以及与脑血管痉挛(CVS)的关系。方法通过枕大池二次注血方法制作大鼠SAH模型,以免疫组化方法和逆转录酶-多聚酶链反应分析,分别从蛋白、基因水平分析SAH后基底动脉中p38MAPK信号传导通路的活化情况。结果 SAH后大鼠基底动脉逐渐出现痉挛。基底动脉磷酸化p38MAPK表达逐渐增加,3 d时达高峰并持续至第5 d,14 d时恢复正常。p38MAPK基因表达在注血后1 d明显增加,逐渐增加,于5 d时达高峰,14 d仍维持较高水平。结论SAH后大鼠基底动脉中p38MAPK信号传导通路激活,可能诱导CVS的发生。     

p38MAPK在蛛网膜下腔出血后脑血管痉挛中的作用

目的探讨促分裂原活化蛋白激酶p38(p38MAPK)在蛛网膜下腔出血(SAH)后脑血管痉挛(CVS) 中的作用。方法采用枕大池二次注血的方法建立SAH模型。用酶联免疫吸附测定法(ELISA)、免疫组织化学、测量基底动脉横截面积的方法分别检测兔脑脊液肿瘤坏死因子-α(TNF—α)浓度变化及平滑肌细胞p38MAPK的表达与CVS程度变化的关系。结果 TNF—α浓度在注血后第3天达高峰,持续到第5天时,与注血前有明显差异(P< 0．01);平滑肌细胞p38MAPK表达增强;基底动脉横截面积则显著小于对照组(P<0．01)。应用p38MAPK特异性抑制剂SB203580干预后,TNF—α浓度显著降低到注血前水平,平滑肌细胞p38MAPK表达也明显减弱,基底动脉横截面积与对照组相比无明显差异(P>0．05)。结论 SAH后继发性的CVS可能是激活的p38MAPK通过对细胞因子增量调节机制作用的结果。     

蛛网膜下腔出血后大鼠基底动脉肿瘤坏死因子-α的表达变化

目的探讨蛛网膜下腔出血（SAH）后基底动脉肿瘤坏死因子α（TNF-α）的表达变化以及与脑血管痉挛（CVS）的关系。方法通过枕大池二次注血方法制作大鼠SAH模型,HE染色观察基底动脉的血管形态学变化,免疫组化方法观察基底动脉TNF-α的表达情况,酶联免疫吸附试验和逆转录酶-多聚酶链反应,分别从蛋白、基因水平分析TNF-α在SAH后基底动脉中的表达变化情况。结果SAH后大鼠基底动脉逐渐出现痉挛,从1 d开始,5~7 d时最明显,炎性细胞浸润也最明显,以后逐渐减轻,14 d基本恢复正常。TNF-α阳性的内皮细胞数及TNF-α蛋白水平逐渐增高,术后7 d达高峰,之后逐渐降低,14 d时仍维持较高水平。TNF-αmRNA表达在注血后1 d明显增加,7 d时达高峰,持续到14 d,仍维持较高水平。结论①大鼠枕大池二次注血后基底动脉呈现痉挛状态;②基底动脉TNF-α表达变化与动脉痉挛程度呈正相关,表明TNF-α可能导致SAH后基底动脉痉挛。     

酪氨酸激酶抑制剂对大鼠蛛网膜下腔出血后脑血管痉挛的作用研究

目的 探讨酪氨酸激酶（Src）在蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）中的作用和机制，以及应用Src抑制剂PP2对脑血管痉挛的治疗作用。方法 枕大池二次注血法制作大鼠SAH模型，造模后第1天至第5天腹腔注射10mmol/L Src抑制剂PP20．1ml，对照组注射等体积DMSO。第5天处死动物，H-E染色观察大鼠基底动脉血管直径。Westernblot检测基底动脉Src、Ras、MAPK蛋白表达，Real-timePCR检测基底动脉IL-1β、IL-6mRNA表达。结果 枕大池二次注血法成功制作SAH模型，基底动脉发生了明显血管痉挛。SAH组基底动脉Src、Ras、MAPK表达显著增高，IL-1β、IL-6细胞因子mRNA表达增加。应用PP2后血管痉挛减轻，基底动脉Src、Ras、MAPK表达下降，IL-1β、IL-6mRNA表达减少。结论 Src与SAH后脑血管痉挛发生有关。Src抑制剂PP2能够缓解脑血管痉挛，其机制一部分通过MAPK信号通路起作用，另外可能通过减少IL-1β、ILl6等细胞因子表达，抑制炎症反应起作用，针对该信号通路可能对脑血管痉挛的治疗有效。     

蛛网膜下腔出血大鼠基底动脉血小板源性生长因子的表达变化

目的探讨血小板源性生长因子(PDGF)在大鼠蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)血管壁的表达及关系。方法将30只大鼠按照枕大池二次注血的方法建立模型,然后分别于建立模型后的1 d、3 d、5 d、7 d、14 d将大鼠处死,取出基底动脉制作石蜡切片在光镜下观察。采用免疫组化法检测大鼠基底动脉血管壁PDGF的表达水平。结果模型组中PDGF在基底动脉血管壁上的表达,3 d和5 d组最明显,与脑血管痉挛程度的变化是一致的。结论通过枕大池二次注血能够成功的模拟SAH后CVS的发生。PDGF参与了SAH后CVS的过程,并可能起了重要的作用。     

eNOS与蛛网膜下腔出血后脑血管痉挛的关系

目的 探讨内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)在蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后不同时间点基底动脉表达情况及其与脑血管痉挛的关系.方法 新西兰大白兔72只,随机分成两组:(1)对照组(12只);(2)SAH组(60只).SAH组进一步按时间随机分为术后1d、3d、5d、7d、10d5个亚组,每组12只.采用枕大池二次注血法建立兔SAH模型.二次注血后在各个时间点采用灌流固定法处死动物,测定基底动脉横截面积判断有无脑血管痉挛.应用Western blotting分别观察eNOS在基底动脉中的表达情况.结果 枕大池二次注血法成功制作SAH模型,基底动脉发生了不同程度的血管痉挛.Western blotting观察到eNOS在对照组大量表达,实验组第1天表达开始减少,第5天表达水平最低,之后表达逐渐增加.结论 SAH后eNOS表达水平的变化与脑血管痉挛发展的时相性具有一定的一致性,eNOS蛋白减少可能参与蛛网膜下腔出血后脑血管痉挛的发展.     

蛛网膜下腔出血后白细胞介素-8基因在兔脑基底动脉中表达的变化(英文)

目的探讨实验性蛛网膜下腔出血(SAH)诱发脑血管痉挛时,白细胞介素-8(IL-8)基因在兔脑基底动脉中表达的变化及在诱发脑血管痉挛中的作用。方法 35只健康日本大耳白兔随机分为生理盐水组、SAH组。SAH组根据第一次注血时间又分为四组,分别为第一次注血后第1、4、7、14 天。以枕大池二次注血法构建迟发性脑血管痉挛模型,采用RT-PCR法观察兔基底动脉中细胞因子IL-8 mRNA表达的变化。结果 IL-8mRNA在SAH组第一次注血后第4- 7天升高,14 天趋于正常。SAH组IL-8 的表达水平与基底动脉的狭窄程度呈正相关(r = 0.642,P < 0.01)。结论 IL-8在基底动脉中的表达水平与脑血管痉挛的程度紧密相关,提示IL-8可能作为免疫/炎症因素因素参与了SAH 后迟发性脑血管痉挛的发生。     

骨桥蛋白对大鼠蛛网膜下腔出血后脑血管痉挛的作用

目的探究重组骨桥蛋白(r-OPN)对蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用及其可能机制。方法将48只大鼠随机分为假手术+安慰剂组、SAH+安慰剂组、SAH+低剂量rOPN组和SAH+高剂量r-OPN组。采用枕大池二次注血法建立SAH模型。首次注血后72 h取脑脊液,处死大鼠,通过测量基底动脉横截面积和管壁厚度判断脑血管痉挛情况,采用酶联免疫吸附法(ELISA)检测脑脊液中内皮素-1(ET-1)水平,Western blot测定基底动脉磷酸化内皮型一氧化氮合酶(p-e NOS)和诱导型一氧化氮合酶(i NOS)水平。结果与SAH+安慰剂组相比,SAH+高剂量r-OPN组大鼠基底动脉横截面积明显增加,管壁厚度明显减轻,脑脊液ET-1水平明显降低,基底动脉pe NOS表达明显升高,i NOS表达明显降低。结论 r-OPN能有效缓解SAH后CVS,其机制可能与抑制ET-1的产生、降低i NOS的表达,提高p-e NOS的表达有关。     

大鼠两种脑血管痉挛模型的早期脑损伤研究

目的研究大鼠蛛网膜下腔出血后脑血管痉挛模型的早期脑损伤程度。方法将Wistar大鼠随机分为假手术组、枕大池一次注血组及二次注血组。制模后24h灌注取脑,采用HE染色观察基底动脉,TUNEL检测细胞凋亡,免疫组化染色检测Bax和Bcl-2的表达水平。结果枕大池二次注血组的基底动脉横截面积明显小于假手术组(P0.01)。电镜下海马组织呈现损伤表现。同假手术组比较,注血组大脑皮层及海马组织中凋亡细胞计数明显增加,Bax的表达增强,而Bcl-2的表达下降(P0.01)。结论枕大池一次注血及二次注血法均可复制蛛网膜下腔出血后脑血管痉挛模型,并造成早期脑损伤。     

氯高铁血红素诱导血红素氧合酶-1抗脑血管痉挛实验研究

目的探讨氯高铁血红素诱导血红素氧合酶-1(HO-1)的表达变化和迟发性脑血管痉挛(DCV)之间的关系。方法采用大鼠枕大池二次注血法建立蛛网膜下腔出血(SAH)后DCV模型,对照组注入等体积(0.3 ml)的生理盐水,氯高铁血红素诱导组每日通过腹腔注射氯高铁血红素(30 mg/kg)。监测各组基底动脉血管内径周长和血管壁厚,用逆转录多聚酶链式反应(RT-PCR)检测基底动脉HO-1 mRNA表达变化。结果对照组不同时相基底动脉中无HO-1 mRNA的表达,SAH后大鼠基底动脉有HO-1 mRNA的低表达,氯高铁血红素诱导组HO-1的表达增高,并能减轻DCV的发生。结论 HO-1表达增高能够拮抗SAH后DCV的发生。     

Genetics of neurofibromatosis 1 and the NF1 gene

Neurofibromatosis 1 serves as a paradigm for understanding the principles of human genetics. The concepts of gene mutation, penetrance of the condition, variable clinical expressivity, mosaicism, age-dependent expression of clinical manifestations, and pleiotropy are evident in this autosomal dominant condition. The lack of genotype-phenotype correlation, except the whole-gene deletion phenotype, leads to speculation on modifiers of the haploinsufficient state of the NF1 gene product neurofibromin. The variant form of neurofibromatosis, neurofibromatosis Noonan's syndrome, suggests potential interaction of independent biochemical pathways. Identification of the NF1 gene led to the discovery of its role in ras signal transduction. Neurofibromin is a negative regulator of intracellular ras signaling. This observation now provides the framework for the development of rational medical therapies. In addition, knowledge of the molecular basis of the variable expression of clinical manifestations could provide better anticipatory guidance and more effective management of the medical complications that are associated with this condition.     

Genetic polymorphisms of glutathione S-transferases GSTM1, GSTT1, GSTP1 and GSTA1 as risk factors for schizophrenia

Oxidative damage is thought to play a role in the predisposition to schizophrenia. We determined if the polymorphisms of the GSTP1, GSTM1, GSTT1 and GSTA1 genes, which affect the activity of these enzymes against oxidative stress, have a role as susceptibility genes for schizophrenia, analyzing 138 schizophrenic patients and 133 healthy controls. We found that the combination of the absence of GSTM1 gene with the of the GSTM1 gene with the polymorphism GSTA1*B/*B, and the presence of the GSTT1 gene, represents a risk factor for schizophrenia, indicating that the combination of different GST polymorphisms has a role in the predisposition to schizophrenia, probably affecting the capacity of the cell to detoxify the oxidized metabolites of catecholamines.     

Cardiovascular effects of centrally applied endothelin-1 1-31 and its relationship to endothelin-1 1-21 in rats

Endothelin-1(1-31) (ET-1(1-31)) is a novel member of the endothelin family, which comprises 31 amino acids and derived from the selective hydrolysis of big ET-1 by chymase. Although ET-1(1-31) has been reported to be involved in biological effects via direct or indirect (converting to ET-1(1-21)) mechanisms, the cardiovascular effects of central ET-1(1-31) are not fully identified. The present study was designed to comparatively investigate the cardiovascular effects of intracerebroventricular (icv) application of ET-1(1-31) or ET-1(1-21) in anesthetized rats. Injection (icv) of ET-1(1-31) (500 pmol) produced a biphasic blood pressure response: an initial increase (from 118+/-8 to 138+/-14 mmHg, P<0.05) followed by a sustained decrease in BP (from 118+/-8 to 58+/-9 mmHg, P<0.05), which was very similar to BP response to icv injection of big ET-1 (500 pmol) or ET-1(1-21) (25 pmol)(.) The cardiovascular effects of icv injection of ET-1(1-31) or ET-1(1-21) were completely antagonized by ET(A) receptor antagonist BQ123 but not ET(B) receptor antagonist BQ788. Furthermore, pretreatment with ET converting enzyme inhibitor phosphoramidon (10 nmol) abolished the cardiovascular effects evoked by icv injection of ET-1(1-31) or big ET-1. In conclusion, the current data showed that central ET-1(1-31) produced the similar cardiovascular effects as those of central ET-1(1-21), and suggesting that the central cardiovascular effects of ET-1(1-31) resulted from it converting to ET-1(1-21) and then activating ET(A) receptors.     

High prevalence of ADHD symptoms in unmedicated youths with post-H1N1 narcolepsy type 1

ObjectivesTo characterize attention deficit-hyperactivity disorder (ADHD) symptoms in unmedicated post-H1N1 narcolepsy type 1 (NT1) youths, and explore associations between ADHD symptoms and the narcolepsy phenotype.MethodsA total of 50 consecutively enrolled post-H1N1 NT1 youths (7–20 years, 62% females, 98% HLA-DQB1106:02-positive, 98% CSF hypocretin-1 deficient, 88% vaccinated) were assessed after two weeks off medication for ADHD (ADHD diagnosis pre/post-narcolepsy, parent-rated ADHD symptoms) and narcolepsy-phenotyped (semi-structured interview, Stanford Sleep Questionnaire, Epworth Sleepiness Scale, polysomnography (PSG), Multiple Sleep Latency Test (MSLT)).ResultsIn sum, 26 (52%) and 15 (30%) of participants had ADHD symptoms above and below the clinical significant cut-off, respectively, while 9 (18%) had no ADHD symptoms. High values were found for ADHD total score (mean (SD), 17.9 (9.5)) and ADHD subscores (inattentive score, 11.0 (6.3); hyperactive/impulsivity score, 6.9 (4.7)). These were significantly higher than previously reported in a mainly medicated narcolepsy cohort (p < 0.0001). Age, gender and disease duration did not influence scores. Two participants (4%) had ADHD diagnosis prior to narcolepsy onset. ADHD symptoms were correlated with parent-rated, but not with patient rated ESS scores, objective sleepiness (mean sleep latency), sleep fragmentation (sleep stage shift index, awakening index), or CSF hypocretin-1 level.ConclusionComorbid ADHD symptoms were more prevalent in unmedicated post-H1N1 NT1 youths than previously reported in mainly medicated pediatric narcolepsy cohorts. The high prevalence was not due to pre-existing ADHD and generally not correlated with core narcolepsy sleep/wake phenotype characteristics, indicating that the ADHD symptoms were not a direct consequence of disturbed sleep or daytime sleepiness.     

The wmN1 enhancer region in intron 1 is required for expression of human PLP1

The myelin proteolipid protein gene (PLP1) encodes the most abundant protein present in myelin from the central nervous system (CNS). Its expression must be tightly controlled as evidenced by mutations that alter PLP1 dosage; both overexpression (elevated PLP1 copy number) and lack thereof (PLP1 deletion) result in X‐linked genetic disorders in man. However, not much is known about the mechanisms that govern expression of the human gene. To address this, transgenic mice were generated which utilize human PLP1 (hPLP1) sequences (proximal 6.2 kb of 5′‐flanking DNA to the first 38 bp of exon 2) to drive expression of a lacZ reporter cassette. LoxP sites were incorporated around a 1.5‐kb section of hPLP1 intron 1 since it contains sequence orthologous to the wmN1 region from mouse which, previously, was shown to augment expression of a minimally‐promoted transgene coincident with the active myelination period of CNS development. Eight transgenic lines were generated with the parental, 6.2hPLP(+)Z/FL, transgene. All lines expressed the transgene appropriately in brain as evidenced by staining with X‐gal in white matter regions and olfactory bulb. Removal of the “wmN1” region from 6.2hPLP(+)Z/FL with a ubiquitously expressed Cre‐driver caused a dramatic reduction in transgene activity. These results demonstrate for the first time that the wmN1 enhancer region: (1) is functional in hPLP1; (2) works in collaboration with its native promoter—not just a basal heterologous promoter; (3) is required for high levels of hPLP1 gene activity; (4) has a broader effect, both spatially and temporally, than originally projected with mPlp1.