虾青素对小鼠蛛网膜下腔出血早期脑损伤的保护机制的研究

目的 研究虾青素对小鼠蛛网膜下腔出血（SAH）早期脑损伤的保护机制。方法 ICR雄性小鼠采用随机数字法随机分为四组：蛛网膜下腔出血组、假手术组、蛛网膜下腔出血+溶剂组（DMSO）、蛛网膜下腔出血+虾青素组。通过建立小鼠视交叉注血方法建立蛛网膜下腔出血模型，于手术后24 h记录神经功能评分，并应用末端脱氧核苷酸转移酶介导的生物素脱氧尿嘧啶核苷酸缺口末端标记法（TUNEL）、western blot法检测脑组织中的NOX2蛋白含量、ELISA法检测TNF-a/IL-1β水平，干湿法检测脑组织中含水量。结果 与对照组相比，SAH后小鼠神经功能损伤评分加重，脑水肿加重，脑组织中的NOX2蛋白及脑组织中凋亡阳性细胞数也显著增多，TNF-a/IL-1β值明显升高；应用虾青素干预以后，小鼠神经功能改善，脑组织凋亡阳性细胞明显减少。同时，虾青素能够降低SAH后小鼠脑组织中NOX2蛋白，TNF-a/IL-1β水平值也明显降低。结论 虾青素对sAH后早期脑损伤（EBI）具有保护作用，其作用机制可能与其抗氧化性有关。     

舒芬太尼对大鼠蛛网膜下腔出血后脑损伤的保护作用

目的 探讨舒芬太尼对大鼠蛛网膜下腔出血（SAH）后脑损伤的作用及其机制。方法 取60只成年SD大鼠随机分为假手术组、模型组和舒芬太尼组,每组20只。采用血管内穿孔法建立SAH模型,舒芬太尼组建模后6 h尾静脉注射舒芬太尼溶液（5 μg/kg,1次/d,连续3周）,假手术组和模型组尾静脉注射等量生理盐水。造模后1、2、21 d,采用改良改良神经严重性量表（mNSS）评分评估神经功能;末次神经功能评估结束后,采用湿干重比法测定脑含水量,TUNEL染色检测神经元凋亡率,EILSA法测定脑组织MDA、SOD、GSH-PX、IL-1β、IL-6和TNF-α的含量,免疫印迹法检测Nrf2、HO-1、NF-κB p65、BCL-2和cleaved-caspase-3蛋白的表达。结果 与假手术组相比,模型组大鼠mNSS显著增高（P<0.001）,脑含水量显著增加（P<0.05）,神经元细胞凋亡率显著增加（P<0.001）,脑组织MDA、TNF-α、IL-1β、IL-6、NF-kB p65和cleaved-caspase-3水平显著升高（P<0.01）,而脑组织SOD、GSH-Px、BCL-2、Nrf2和HO-1水平显著降低（P<0.05）。与模型组相比,舒芬太尼组大鼠上述改变明显改善（P<0.05）。结论 舒芬太尼对SAH后脑损伤有保护作用,其机制可能其抗细胞凋亡、抗氧化应激和抗炎症反应等作用有关。     

虾青素对小鼠蛛网膜下腔出血早期脑损伤的保护机制的研究

目的研究虾青素对小鼠蛛网膜下腔出血(SAH)早期脑损伤的保护机制。方法 ICR雄性小鼠采用随机数字法随机分为四组:蛛网膜下腔出血组、假手术组、蛛网膜下腔出血+溶剂组(DMSO)、蛛网膜下腔出血+虾青素组。通过建立小鼠视交叉注血方法建立蛛网膜下腔出血模型,于手术后24 h记录神经功能评分,并应用末端脱氧核苷酸转移酶介导的生物素脱氧尿嘧啶核苷酸缺口末端标记法(TUNEL)、western blot法检测脑组织中的NOX2蛋白含量、ELISA法检测TNF-a/IL-1β水平,干湿法检测脑组织中含水量。结果与对照组相比,SAH后小鼠神经功能损伤评分加重,脑水肿加重,脑组织中的NOX2蛋白及脑组织中凋亡阳性细胞数也显著增多,TNF-a/IL-1β值明显升高;应用虾青素干预以后,小鼠神经功能改善,脑组织凋亡阳性细胞明显减少。同时,虾青素能够降低SAH后小鼠脑组织中NOX2蛋白,TNF-a/IL-1β水平值也明显降低。结论虾青素对s AH后早期脑损伤(EBI)具有保护作用,其作用机制可能与其抗氧化性有关。     

激光散斑成像法监测格列本脲对小鼠SAH后脑微循环的影响

目的 探讨格列本脲对小鼠蛛网膜下腔出血（SAH）后脑微循环的影响。方法 将28只雄性C57小鼠随机分为对照组（n=6）、SAH组（n=6）、溶媒组（n=6）和格列本脲组（n=10）。视交叉前池注入自体非抗凝尾动脉血60 μl建立SAH模型。小鼠SAH后5 min内，格列本脲组腹腔注射格列本脲（25 μg/kg），溶媒组腹腔注射等体积二甲基亚砜；SAH组未进行任何治疗。造模后12 h，应用Garcia量表评分评估神经功能；造模前后使用激光散斑血流成像监测脑皮层灌注以及体感刺激下感觉皮层血流响应幅度。结果 造模后12 h，SAH组、溶媒组神经功能评分明显下降（P<0.05），脑感觉皮层灌注明显下降（P<0.05），体感刺激下感觉皮层血流响应幅度明显下降（P<0.05）。应用格列本脲后，小鼠神经功能评分明显增高（P<0.05），脑感觉皮层血流响应幅度和感觉皮层灌注明显改善（P<0.05）。结论 格列本脲可以改善小鼠SAH后神经功能，可能与改善脑微循环有关     

葛根素通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤的神经保护作用

目的 探讨葛根素对创伤性脑损伤(TBI)模型大鼠的神经保护作用及脑组织红系衍生的核因子相关因子2(Nrf2)一抗氧化反应原件(ARE)信号通路参与的机制。方法 选择健康成年雄性大鼠体重250～300 g构建TBI模型,将大鼠分为4组:创伤组(A组)、假手术组(B组)、葛根素治疗的创伤组(C组)和葛根素治疗的假手术组(D组); 通过采用改良的神经功能缺损评分(mNSS)评价神经功能,脑组织干湿重称量法评价脑水肿,Nissl染色,TUNEL染色评价脑损伤体积和神经元的凋亡,使用酶活试剂盒检测损伤48 h后抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平,最后使用western blot和RT-PCR的方法检测Nrf2-ARE信号通路及其下游分子HO-1,NQO1的表达水平。结果 TBI手术后损伤组mNSS评分明显增高(P<0.05),葛根素治疗组能够明显降低mNSS评分(P<0.05)。TBI手术后损伤组脑水肿加重及神经元凋亡增加(P<0.05),葛根素治疗组能够明显挽救脑水肿及神经元凋亡(P<0.05)。TBI手术12 h后损伤组脑内抗氧化酶SOD,GSH,和GSSG的活性增加及氧化应激产物MDA和NO的水平升高(P<0.05),葛根素治疗组能够明显降低抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平(P<0.05)。western blot和RT-PCR显示葛根素不改变Nrf2的翻译和表达,但是RT-PCR显示葛根素能够明显促进Nrf2-ARE信号通路下游分子HO-1,NQO1的表达。结论 葛根素可能通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤发挥神经保护作用。     

丹红注射液对大鼠蛛网膜下腔出血后脑血管痉挛的影响

目的 探讨丹红注射液对大鼠蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的防治作用。方法 将84只健康成年SD 大鼠随机分成4 组:正常组（n=12）、生理盐水组（n=24）、SAH组（n=24）和丹红组（n=24）;后3组根据造模后取材时间,各分为造模后3 d和7 d两亚组,每亚组12只大鼠。采用枕大池二次注血法建立大鼠SAH 模型。丹红组在造模后每天给予一次丹红注射液腹腔注射治疗。按上述时间点灌注固定后取大鼠脑桥段基底动脉,行HE染色,400倍光镜下观察,并测量基底动脉内径、血管壁厚度。结果 造模后3 d、7 d,生理盐水组基底动脉内径、管壁厚度与正常组均无明显变化（P>0.05）。造模后3 d,与生理盐水组相比,SAH组和丹红组基底动脉内径明显缩小,管壁厚度明显增加（P<0.05）;但SAH组和丹红组之间无统计学差异（P>0.05）。造模7 d后,SAH组基底动脉内径近一步缩小（P<0.05）,管壁厚度进一步增加（P<0.05）;而丹红组基底动脉内径较SAH组明显增加（P<0.05）,管壁厚度明显变薄（P<0.05）。结论 丹红注射液对大鼠SAH后CVS有一定的缓解作用。     

针刺对急性脑挫裂伤大鼠脑组织内p-CREB表达的影响

目的探讨针刺对急性脑挫裂伤大鼠磷酸化的环磷酸腺苷反应元件结合蛋白(p-CREB)表达的影响。方法 48只雄性SD大鼠随机分为针刺治疗组、模型对照组、正常对照组,每组16只。模型对照组仅制备急性脑挫裂伤模型,针刺治疗组在建立模型后行针刺治疗,正常对照组不致伤。损伤后48 h、6 d取损伤或对应局部脑组织,采用免疫组化法观察p-CREB的表达变化,并进行统计学分析。结果伤后48 h、6 d,模型对照组损伤脑组织中p-CREB的表达较正常对照组升高(均P<0.05),针刺治疗组损伤脑组织中p-CREB表达较模型对照组显著升高(均P<0.05)。伤后6 d针刺治疗组p-CREB表达较伤后48 h降低(P<0.05)。结论针刺治疗对大鼠颅脑损伤后p-CREB的表达具有明显的促进作用,并呈一定规律性,提示p-CREB与颅脑损伤后脑组织的修复相关。     

辛伐他汀对蛛网膜下腔出血早期脑损伤大鼠NLRP3炎性小体的表达及NF-κB信号通路的影响

目的 探究辛伐他汀(simvastatin)对蛛网膜下腔出血(SAH)早期脑损伤(EBI)大鼠NLRP3的表达及NF-κB信号通路的影响。方法 100只大鼠随机分为假手术(Sham)组、SAH组、Simvastatin组、NF-κB信号通路抑制剂(PJ34)组,每组25只。视交叉前池注血法构建SAH模型,建模后2h给药,Simvastatin组、PJ34组腹腔注射辛伐他汀和PJ34,另外两组腹腔注射等体积生理盐水。1次·d^-1,连续14 d。给药结束24 h后,采用Garcia评分评估造模后大鼠的神经功能;Sugawara出血量评分评价脑组织出血情况;苏木精-伊红染色、透射电镜观察脑组织病理变化与超微结构损伤;测定脑组织含水量;TUNEL染色、ELISA、免疫组化分别检测细胞凋亡情况、炎症因子表达水平与NLRP3表达情况;Western blotting检测脑组织NLRP3、Caspase-1、核因子-κB (NF-κB-p65)的表达水平。结果 与SAH组相比,Simvastatin组SAH、炎性浸润明显减轻,脑组织病理损伤明显改善,脑组织含水量、神经细胞凋亡、...     

内脂素改善创伤性脑损伤小鼠神经功能修复的研究

目的研究内脂素对创伤性脑损伤（TBI）小鼠的神经功能保护作用及机制。 方法通过液压冲击方法建立C57BL/6小鼠液压冲击脑损伤模型，共48只，然后随机分为实验组A、实验组B、对照组，各16只。模型建立3 h后起，实验组A和实验组B分别给予腹腔注射内脂素15、30 μg/kg，1次/d，共7 d，对照组给予腹腔注射生理盐水。治疗开始前、开始治疗后第3、14、28天各组随机选取10只小鼠，比较实验组和对照组小鼠的神经功能缺损评分（NSS）；治疗结束后第2天，每组随机取3只小鼠全脑取材，比较TUNEL染色后阳性细胞差异；再随机取3只收集脑组织总蛋白，比较各组小鼠脑组织凋亡相关蛋白水平差异；剩余10只小鼠在治疗结束后第24~28天，比较Morris水迷宫小鼠逃逸潜伏期时间差异。 结果3组小鼠NSS评分在开始治疗后第3天时差异无统计学意义（P>0.05），但在第14、28天时，内脂素治疗组小鼠NSS评分低于对照组，差异均具有统计学意义（P<0.05）；3组小鼠在治疗结束后24、25 d时水迷宫潜伏逃逸期差异无统计学意义（P>0.05），但在第26、27、28天时，内脂素治疗组小鼠水迷宫潜伏逃逸期小于对照组，差异具有统计学意义（P<0.05）。内脂素治疗组小鼠脑切片中TUNEL阳性细胞数小于对照组，差异具有统计学意义（P<0.05），同时凋亡相关蛋白cleave Caspase-3、cleaved PARP的表达量也低于对照组，差异具有统计学意义（P<0.05）。 结论内脂素能够抑制小鼠TBI后病灶周围神经细胞的凋亡及降低凋亡相关蛋白的表达量，改善神经功能的修复。     

褪黑激素抑制NLRP3炎性小体减轻小鼠蛛网膜下腔出血早期脑损伤

目的探讨褪黑素通过调节核苷酸结合寡聚化结构域样受体3炎症复合体(NLRP3)对蛛网膜下腔出血(SAH)后早期脑损伤(EBI)的保护作用和机制。方法建立小鼠颈动脉线穿法SAH模型,分为假手术组、假手术+溶剂组、SAH+溶剂组和SAH+褪黑素组四组,进行SAH出血量评级和小鼠神经功能缺陷评分,脑组织水含量测定脑水肿,伊文思蓝法测定血脑屏障(BBB)通透性,检测脑丙二醛(MDA)和谷胱甘肽(GSH)水平,神经核抗原(Neu N)和末端脱氧核苷酸转移酶介导的d UTP缺口末端标记测定法(TUNEL)检测神经元存活和死亡率,Western Blot检测脑凋亡相关斑点样蛋白(ASC)、白细胞介素-1β(IL-1β)、核苷酸结合寡聚化结构域样受体3炎症复合体(NLRP3)、B淋巴细胞瘤-2基因(Bcl2)、前凋亡因子(Bim)和活化的caspase-1蛋白表达,酶联免疫吸附测定(ELISA)脑中细胞因子白介素-1β(IL-1β)和白介素-6(IL-6)水平。结果槲皮素可以提高SAH小鼠生存率,降低神经功能缺陷评分,减少脑神经元凋亡,提高脑谷胱甘肽(GSH)水平,降低丙二醛(MDA)水平,减轻脑水肿和BBB通透性损害。槲皮素可以降低NLRP3以及细胞凋亡相关斑点样蛋白(ASC)的表达,抑制IL-1β、IL-6的分泌和活化的caspase-1的蛋白表达,并可以增高抗凋亡因子Bcl2的表达,降低凋亡前体因子Bim的表达。结论槲皮素通过抑制NLRP3炎性相关的凋亡来减轻SAH后的EBI。     

Apigenin attenuates oxidative stress and neuronal apoptosis in early brain injury following subarachnoid hemorrhage

Apigenin (API) is a naturally occurring plant flavone that exhibits powerful antioxidant and antiapoptosis. Oxidative stress plays an important role in the pathogenesis of early brain injury (EBI) following subarachnoid hemorrhage (SAH). The potential anti-oxidative and anti-apoptosis effects of API on EBI following SAH, however, have not been elucidated. The aim of this study was to assess whether API alleviates EBI after SAH via its anti-oxidative and anti-apoptotic effects. The endovascular puncture model was used to induce SAH and all the rats were subsequently sacrificed at 24 h after SAH. Our data demonstrated that administration of API could significantly alleviate EBI (including neurological deficiency, brain edema, blood–brain barrier permeability, and cortical cell apoptosis) after SAH in rats. Meanwhile, API treatment reduced the reactive oxygen species (ROS) level and the concentration of malondialdehyde (MDA) and myeloperoxidase (MPO), elevated the ratio of glutathione (GSH) and oxidized glutathione (GSSG), and increased the amount of super-oxide dismutase (SOD) and hydrogen peroxide in brain cortex at 24 h following SAH. Moreover, API treatment inhibited SAH-induced the expression of Bax and caspase-3, significantly reduced neuronal apoptosis. Collectively, API exerts its neuroprotective effect likely through the dual activities of anti-oxidation and anti-apoptosis, at least partly. These data provide a basic platform to consider API may be safely used as a potential drug for treatment of SAH.     

INT-777 attenuates NLRP3-ASC inflammasome-mediated neuroinflammation via TGR5/cAMP/PKA signaling pathway after subarachnoid hemorrhage in rats

BackgroundInflammasome-mediated neuroinflammation plays an important role in the pathogenesis of early brain injury (EBI) following subarachnoid hemorrhage (SAH). The activation of the TGR5 receptor has been shown to be neuroprotective in a variety of neurological diseases. This study aimed to investigate the effects of the specific synthetic TGR5 agonist, INT-777, in attenuating NLRP3-ASC inflammasome activation and reducing neuroinflammation after SAH.MethodsOne hundred and eighty-four male Sprague Dawley rats were used. SAH was induced by the endovascular perforation. INT-777 was administered intranasally at 1 h after SAH induction. To elucidate the signaling pathway involved in the effect of INT-777 on inflammasome activation during EBI, TGR5 knockout CRISPR and PKA inhibitor H89 were administered intracerebroventricularly and intraperitoneally at 48 h and 1 h before SAH. The SAH grade, short- and long-term neurobehavioral assessments, brain water content, western blot, immunofluorescence staining, and Nissl staining were performed.ResultsThe expressions of endogenous TGR5, p-PKA, and NLRP3-ASC inflammasome were increased after SAH. INT-777 administration significantly decreased NLRP3-ASC inflammasome activation in microglia, reduced brain edema and neuroinflammation, leading to improved short-term neurobehavioral functions at 24 h after SAH. The administration of TGR5 CRISPR or PKA inhibitor (H89) abolished the anti-inflammation effects of INT-777, on NLRP3-ASC inflammasome, pro-inflammatory cytokines (IL-6, IL-1β, and TNF-a), and neutrophil infiltration at 24 h after SAH. Moreover, early administration of INT-777 attenuated neuronal degeneration in hippocampus on 28 d after SAH.ConclusionsINT-777 attenuated NLRP3-ASC inflammasome-dependent neuroinflammation in the EBI after SAH, partially via TGR5/cAMP/PKA signaling pathway. Early administration of INT-777 may serve as a potential therapeutic strategy for EBI management in the setting of SAH.     

TSG-6 Attenuates Oxidative Stress-Induced Early Brain Injury in Subarachnoid Hemorrhage Partly by the HO-1 and Nox2 Pathways

BackgroundEarly brain injury (EBI) refers to acute brain injury during the first 72 h after subarachnoid hemorrhage (SAH), which is one of the major causes of poor prognosis after SAH. Here, we investigated the effect and the related mechanism of TSG-6 on EBI after SAH.Materials and methodsThe Sprague-Dawley rat model of SAH was developed by the endovascular perforation method. TSG-6 (5μg) was administered by an intraventricular injection within 1.5 h after SAH. The effects of TSG-6 on EBI were assessed by neurological score, brain water content (BWC) and TUNEL staining. Immunofluorescence staining was used to assay NF-κB/p-NF-κB expression in microglia. Protein expression levels of heme oxygenase-1 (HO-1), NADPH oxidase 2 (Nox2), Bcl-2, Bax, and cleaved-caspase-3 were measured to investigate the potential mechanism. The enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the level of reactive oxygen species (ROS) were analyzed using commercially available kits.ResultsThe results showed that TSG-6 treatment alleviated the neurobehavioral dysfunction and reduced BWC and the number of TUNEL-positive neurons in EBI after SAH. TSG-6 decreased the ROS level and enhanced the enzyme activity of SOD and GSH-Px after SAH. Furthermore TSG-6 inhibited the NF-κB activation, increased the protein expression levels of HO-1 and Bcl-2 and decreased the expression levels of Nox2, Bax, and cleaved-caspase-3. The administration of TSG-6 siRNA abolished the protective effects of TSG-6 on EBI after SAH.ConclusionWe found that TSG-6 attenuated oxidative stress and apoptosis in EBI after SAH partly by inhibiting NF-κB and activating HO-1 pathway in brain tissue.     

Fluoxetine is Neuroprotective in Early Brain Injury via its Antiinflammatory and Anti-apoptotic Effects in a Rat Experimental Subarachnoid Hemorrhage Model

Fluoxetine, an anti-depressant drug, has recently been shown to provide neuroprotection in central nervous system injury, but its roles in subarachnoid hemorrhage(SAH) remain unclear. In this study, we aimed to evaluate whether fluoxetine attenuates early brain injury(EBI) after SAH. We demonstrated that intraperitoneal injection of fluoxetine(10 mg/kg per day) significantly attenuated brain edema and blood-brain barrier(BBB) disruption, microglial activation, and neuronal apoptosis in EBI after experimental SAH, as evidenced by the reduction of brain water content and Evans blue dye extravasation, prevention of disruption of the tight junction proteins zonula occludens-1, claudin-5, and occludin, a decrease of cells staining positive for Iba-1, ED-1, and TUNEL and a decline in IL-1 b, IL-6, TNF-a, MDA, 3-nitrotyrosine, and 8-OHDG levels. Moreover, fluoxetine significantly improved the neurological deficits of EBI and long-term sensorimotor behavioral deficits following SAH in a rat model. These results indicated that fluoxetine has a neuroprotective effect after experimental SAH.     

Tenascin-C in brain injuries and edema after subarachnoid hemorrhage: Findings from basic and clinical studies

Subarachnoid hemorrhage (SAH) by a rupture of cerebral aneurysms remains the most devastating cerebrovascular disease. Early brain injury (EBI) is increasingly recognized to be the primary determinant for poor outcomes, and also considered to cause delayed cerebral ischemia (DCI) after SAH. Both clinical and experimental literatures emphasize the impact of global cerebral edema in EBI as negative prognostic and direct pathological factors. The nature of the global cerebral edema is a mixture of cytotoxic and vasogenic edema, both of which may be caused by post-SAH induction of tenascin-C (TNC) that is an inducible, non-structural, secreted and multifunctional matricellular protein. Experimental SAH induces TNC in brain parenchyma in rats and mice. TNC knockout suppressed EBI in terms of brain edema, blood-brain barrier disruption, neuronal apoptosis and neuroinflammation, associated with the inhibition of post-SAH activation of mitogen-activated protein kinases and nuclear factor-kappa B in mice. In a clinical setting, more severe SAH increases more TNC in cerebrospinal fluid and peripheral blood, which could be a surrogate marker of EBI and predict DCI development and outcomes. In addition, cilostazol, a selective inhibitor of phosphodiesterase type III that is a clinically available anti-platelet agent and is known to suppress TNC induction, dose-dependently inhibited delayed cerebral infarction and improved outcomes in a pilot clinical study. Thus, further studies may facilitate application of TNC as biomarkers for non-invasive diagnosis or assessment of EBI and DCI, and lead to development of a molecular target drug against TNC, contributing to the improvement of post-SAH outcomes.     

蛛网膜下腔出血后早期脑损伤的研究进展

蛛网膜下腔出血(SAH)是由多种脑血管疾病引起的一种复杂的临床综合征,可对中枢神经系统产生灾难性打击,其高致残率、病死率显著影响了患者的神经认知功能恢复,加重家庭和社会经济负担.其中颅内动脉瘤破裂出血是SAH最常见的病因(85％).近年来,多项研究表明早期脑损伤(EBI)是导致蛛网膜下腔出血预后不良的重要因素.脑表面或...     

Fluoxetine is Neuroprotective in Early Brain Injury <Emphasis Type="Italic">via</Emphasis> its Anti-inflammatory and Anti-apoptotic Effects in a Rat Experimental Subarachnoid Hemorrhage Model

Fluoxetine, an anti-depressant drug, has recently been shown to provide neuroprotection in central nervous system injury, but its roles in subarachnoid hemorrhage (SAH) remain unclear. In this study, we aimed to evaluate whether fluoxetine attenuates early brain injury (EBI) after SAH. We demonstrated that intraperitoneal injection of fluoxetine (10 mg/kg per day) significantly attenuated brain edema and blood-brain barrier (BBB) disruption, microglial activation, and neuronal apoptosis in EBI after experimental SAH, as evidenced by the reduction of brain water content and Evans blue dye extravasation, prevention of disruption of the tight junction proteins zonula occludens-1, claudin-5, and occludin, a decrease of cells staining positive for Iba-1, ED-1, and TUNEL and a decline in IL-1β, IL-6, TNF-α, MDA, 3-nitrotyrosine, and 8-OHDG levels. Moreover, fluoxetine significantly improved the neurological deficits of EBI and long-term sensorimotor behavioral deficits following SAH in a rat model. These results indicated that fluoxetine has a neuroprotective effect after experimental SAH.     

Role of autophagy in early brain injury after experimental subarachnoid hemorrhage

Autophagy is a self-degradative process and it plays a housekeeping role in removing misfolded or aggregated proteins, clearing damaged organelles, and eliminating intracellular pathogens. Previous studies have demonstrated that autophagy pathway was activated in brain after experimental subarachnoid hemorrhage (SAH); however, the role of autophagy in the pathogenesis of early brain injury (EBI) following SAH remains unknown. Experiment 1 aimed to investigate the time–course of the autophagy in the cortex following SAH. In experiment 2, we chose the maximum time pointof autophagy activation and assessed the effects of rapamycin (RAP, autophagy activator) and 3-methyladenine (3-MA, autophagy inhibitor) on regulation of EBI. All SAH animals were subjected to injection of 0.3 ml fresh arterial, nonheparinized blood into prechiasmatic cistern in 20 s. As a result, microtubule-associated protein light chain-3 (LC3), a biomarker of autophagosome, and beclin-1, a Bcl-2-interacting protein required for autophagy, were significantly increased at the early stage of SAH and their expressions peaked at 24 h after SAH. In RAP-treated group, the early brain damage such as brain edema, blood–brain barrier (BBB) impairment, cortical apoptosis, and clinical behavior scale was significantly ameliorated in comparison with vehicle-treated SAH rats. Conversely, 3-MA decreased expression of LC3 and beclin-1, increased the average value of brain edema and BBB disfunction, and aggravated neurological deficits. Our results suggest that autophagy pathway is activated in the brain after SAH and may play a beneficial role to EBI development.