受体介导的1-磷酸鞘氨醇信号通路在局灶性脑缺血损伤中作用

目的探讨1-磷酸鞘氨醇(sphingosine 1-phosphate,S1P)受体亚型S1P3在局灶性脑缺血再灌注过程中的作用及其机制,为其作为药物靶点应用到脑缺血再灌注损伤的治疗提供理论依据。方法大脑中动脉闭塞法制备局灶性脑缺血再灌注的小鼠模型。用特异性S1P3拮抗剂CAY10444干预来评测S1P3在脑缺血再灌注中的作用。通过计算药物干预前后脑梗死体积、神经组织学评分和神经退行性变指标评估各组脑损伤程度。采用HE染色以及通过Iba1和Brd U/Iba1免疫组织化学染色方法观察和分析小胶质细胞的活化、形态转化和增殖情况。结果 CAY10444抑制S1P3后显著降低MCAO诱导的脑梗死体积、神经功能缺损以及神经退行性变评分和程度。MCAO术后当S1P3活性受到抑制时,Iba1免疫阳性细胞的数量显著减少,脑缺血的核心区和周边区域活化的小胶质细胞数量均明显减少,同时,缺血核心区的小胶质细胞由阿米巴样形状恢复为分枝状形态。在MCAO后MCAO组脑缺血区小胶质细胞增殖明显,表现为Brd U/Iba1双免疫阳性细胞增多。与MCAO组相比,抑制S1P3后Brd U/Iba1双免疫阳性细胞的数量减少。结论 S1P3是缺血再灌注脑损伤的致病介质,其机制可能是其参与调节了小胶质细胞活化和炎症发生,这为把S1P3作为脑缺血再灌注损伤的治疗靶点提供了依据。     

鞘氨醇-1-磷酸受体调节疗法在多发性硬化治疗中的研究进展

多发性硬化是一种以中枢神经系统慢性炎症、脱髓鞘和轴突损伤为主要特征的自身免疫性疾病,发病机制至今仍未阐明。近10年来口服免疫调节治疗正在兴起,其中鞘氨醇-1-磷酸受体调节剂在多发性硬化的治疗中取得了令人瞩目的疗效。文中主要关注S1P/S1PR信号通路在治疗多发性硬化中的作用、机制和临床应用现状以及展望。     

1-磷酸鞘氨醇与孤独症谱系障碍相关临床表型的 关联性

孤独症谱系障碍（autistic spectrum disorder，ASD）是一组神经发育障碍性疾病，目前病因尚 不明确，其核心症状为社交障碍、重复行为和兴趣受限，其他症状包括认知障碍、感知觉障碍、焦虑抑郁 等。1-磷酸鞘氨醇是神经酰胺的降解产物，在脑组织中含量丰富，在脑发育及调节神经元增殖、分化、存 活和凋亡方面发挥重要作用。已有证据表明1-磷酸鞘氨醇在ASD儿童血清中明显增高，且与其临床表型 相关。现对近年来1-磷酸鞘氨醇与ASD相关临床表型的关联性进行综述。     

木犀草素对实验性自身免疫性脑脊髓炎大鼠SPH/SPHK1/S1P1通路及神经元凋亡的影响

目的 探讨木犀草素(Luteolin)对实验性自身免疫性脑脊髓炎(Experimental autoimmune encephalomyelitis,EAE)大鼠神经酰胺-鞘氨醇(Sphingosine,SPH)/鞘氨醇激酶1(Sphingosine kinase 1,SPHK1)/1-磷酸鞘氨醇受体1(Sphingosine-1-phosphate 1,S1P1)通路蛋白表达水平及神经元凋亡的影响。方法 取雌性Wistar大鼠,采用注射豚鼠脊髓免疫抗原法建立EAE模型,将造模成功的50只大鼠随机分为模型(EAE)组,Luteolin低(5mg/kg)、中(25 mg/kg)、高(50 mg/kg)剂量组,芬戈莫德(FTY720)阳性对照组(61.7 mg/kg),每组各10只; 另取10只雌性Wistar大鼠,注射等量生理盐水,作为空白对照(Control)组; 各组于造模15 d后开始给药,Luteolin低、中、高剂量组经腹腔注射相应剂量Luteolin药物,芬戈莫德(FTY720)阳性对照组灌胃给予相应剂量的FTY720,EAE组和Control组灌胃和腹腔注射等量生理盐水,各组连续给药14 d,2次/d; 各组大鼠于末次给药12 h后对大鼠EAE临床症状进行评分; 取脊髓组织,用苏木精-伊红染色(Hematoxylin eosin,HE)及固蓝(Luxol fast blue,LFB)染色法检测大鼠髓鞘组织病理表现及脱髓鞘面积; 原位缺口末端转移酶标记法(TdT-mediated dUTP nick and labeling,TUNEL)法检测髓鞘组织中神经元的凋亡情况并计算凋亡率; 以蛋白免疫印迹法(Western Blot)检测髓鞘组织中通路蛋白SPHK,SPH,S1P1及凋亡蛋白半胱氨酸天冬氨酸蛋白酶-12(Cystein-asparate protease-12,Caspase-12)蛋白相对表达水平。结果 与Control组比较,EAE组大鼠EAE临床症状评分、脊髓组织炎性细胞浸润和髓鞘脱失程度、神经元凋亡率、髓鞘组织中SPH,SPHK1,S1P1及Caspase-12蛋白表达水平均升高(P<0.05); 与EAE组比较,Luteolin低、中、高剂量组及芬戈莫德(FTY720)阳性对照组大鼠EAE临床症状评分、脊髓组织炎性细胞浸润和髓鞘脱失程度、神经元凋亡率、髓鞘组织中SPH,SPHK1,S1P1及Caspase-12蛋白表达水平均降低(P<0.05),且Luteolin各剂量组上述指标水平呈剂量依赖性; Luteolin高剂量组与芬戈莫德(FTY720)阳性对照组的上述指标水平均无明显差异(P>0.05)。结论 Luteolin可能通过抑制EAE模型大鼠髓鞘组织SPHK,SPH,S1P1蛋白表达来抑制EAE大鼠脱髓鞘病变及神经元凋亡。     

出血性脑卒中患者血清1-磷酸鞘氨醇的表达及其 临床意义

目的 探讨出血性脑卒中患者血清 1- 磷酸鞘氨醇（S1P）表达水平及临床意义。方法 选 取 2016 年 1 月至 2019 年 1 月本院接受手术治疗的出血性脑卒中患者 124 例，其中轻度、中度和重度分 别 28 例、49 例、47 例；预后良好 88 例；预后不良 36 例。选取同期本院体检中心收取的健康人 86 例为 对照。用酶联免疫吸附实验检测血清中 S1P 的表达。建立 Logistic 多因素回归模型分析影响患者预后 的因素；绘制受试者工作特征（ROC）曲线分析 S1P 预测预后的价值。结果 出血性脑卒中患者血清 S1P 浓度为（304.34±86.09）ng/ml，低于健康人［（385.89±98.32）ng/ml，P＜ 0.05］。轻度、中度和重度出血 性脑卒中患者的血清S1P浓度分别为（331.03±100.23）ng/ml、（300.34±78.58）ng/ml、（287.70±66.89）ng/ml， 单因素分析结果显示组间比较差异有统计学意义（F=24.012，P＜ 0.05），病情越重，血清 S1P 浓度越低。 与预后良好患者比较，预后不良患者的年龄、血肿体积和 C- 反应蛋白水平较高，而 S1P 水平和 GCS 评 分较低（P＜ 0.05）。多因素分析结果显示年龄（OR=1.897）、血肿体积（OR=3.903）、GCS 评分（OR=2.003）、 C- 反应蛋白（OR=2.014）、血清神经元特异性烯醇化酶（OR=4.231）和S1P（OR=0.896）是出血性脑卒中患者预 后的独立影响因素（P＜ 0.05）。S1P 预测出血性脑卒中患者不良预后的 ROC 曲线下面积（AUC）为 0.910 （95% CI=0.821～0.968），灵敏度和特异度分别为 82.35% 和 90.12%。S1P 预测的 AUC 高于 C- 反应蛋白 （0.843）。结论 出血性脑卒中患者血清 S1P 表达水平降低，并且与病情严重程度有关，SIP 有助于早期 预测患者的临床预后。     

鞘氨醇激酶1在颞叶癫痫中的作用机制研究

目的观察鞘氨醇激酶1(SphK1)在难治性颞叶癫痫(TLE)患者及匹罗卡品诱导的TLE大鼠模型中的表达,探讨其在TLE发病中的作用机制。方法收集TLE患者手术切除的皮质标本,纳入癫痫组(n=16)。收集脑外伤患者切除的颞叶皮质标本,纳入对照组(n=10)。将72只雄性SD大鼠按随机数字表法分为模型对照组(MC组,n=32)和匹罗卡品组(PILO组,n=40),PILO组根据匹罗卡品诱导癫痫持续状态(SE)后的观察时间随机分为4个亚组:E6h组、E1d组、E3d组和E7d组(n=8)。采用免疫组化染色法检测SphK1在TLE患者颞叶皮质中的表达变化;运用Western blotting法检测SphK1在大鼠海马中的表达变化;采用免疫荧光染色法观察在人颞叶皮质和大鼠海马中星形胶质细胞(AST)活化增生情况和SphK1在AST中的表达。结果癫痫组人颞叶皮质中SphK1的阳性细胞数及AST细胞数均明显多于对照组(均P0.05)。E6h组、E1d组、E3d组和E7d组大鼠海马SphK1表达水平均明显高于MC组(均P0.05);PILO组AST细胞数明显多于MC组(P0.05)。免疫荧光染色结果显示,在癫痫组患者颞叶皮质中,SphK1主要在活化的AST的胞质中表达;而在PILO组大鼠海马中,SphK1主要在活化的AST的胞核中表达。结论 SphK1在TLE患者颞叶皮质和TLE大鼠海马中的表达明显增加,SphK1参与了TLE的发病。     

三七三醇皂苷对大鼠脑缺血/再灌注脑损伤保护作用的实验研究

目的观察三七三醇皂苷（PTS）对大鼠脑缺血／再灌注损伤的脑保护作用，并初步探讨其作用机制。方法采用Longa改良的线栓法制备大脑中动脉阻塞（MACO）2h、再灌注6h、24h、72h的大鼠短暂局灶性脑缺血／再灌注模型，动物随机分假手术组、生理盐水对照组、三七三醇皂苷组。免疫组化法检测IL-1-β和ICAM-1。流式细胞仪检测细胞凋亡，同时利用TTC染色法测脑梗死体积。结果三七三醇皂苷组大鼠再灌注72h时脑梗死体积显著减小，6h、24h、72h各时间点IL-1β和ICAM-1阳性细胞数及凋亡细胞数亦明显减少。结论三七三醇皂苷可抑制脑缺血／再灌注后炎症因子分泌及细胞凋亡，从而起到脑保护作用。     

脑缺血再灌注大鼠细胞间黏附分子-1、血管细胞间黏附分子-1的表达及β-七叶皂甙钠的干预作用

目的研究局灶性脑缺血再灌注过程中脑缺血区细胞间黏附分子-1(ICAM-1)、血管细胞间黏附分子-1(VCAM-1)的表达规律,并探讨β-七叶皂甙钠对其干预的脑保护作用。方法采用线栓法建立大鼠脑缺血再灌注模型,同时应用β-七叶皂甙钠予以干预。用HE染色和免疫组化染色观察大鼠脑缺血后再灌注不同时点组织学改变和ICAM-1、VCAM-1的阳性表达。结果(1)β-七叶皂甙钠明显减轻缺血再灌注后的脑组织损伤;(2)脑缺血再灌注后缺血区微血管内皮细胞ICAM-1、VCAM-1表达增加,ICAM-1于再灌注后24h表达达高峰,VCAM-1.于再灌注后24～48h表达达高峰,随后降低,但再灌注后72h两者表达仍高于正常水平;(3)β-七叶皂甙钠可以显著降低脑缺血再灌注后24h、48h缺血区ICAM-1、VCAM-1的表达。结论脑缺血再灌注后ICAM-1、VCAM—1大量表达,可能是脑缺血再灌注损伤的机制之一;β-七叶皂甙钠能降低ICAM-1和VCAM-1的表达及减轻脑组织损伤,有脑保护作用。     

大鼠脑缺血再灌后凝血酶与PAR-1的表达及意义

目的探讨大鼠脑缺血再灌后凝血酶（thrombin）及蛋白酶活化受体-1（PAR-1）的表达变化及意义。方法栓线法制作大鼠大脑中动脉闭塞再灌注模型,用Western Blot方法检测对照组及脑缺血2h再灌注不同时程组（12、24h,3、7d）凝血酶和PAR1蛋白表达水平。结果对照组可以检测到少量凝血酶（thrombin）和PAR-1的表达,两种蛋白于再灌注12h显著上升。3d达高峰（P〈0．01）,7d下降;缺血再灌注后凝血酶与PAR-1的表达呈高度正相关（r=0．934,P〈0．01）。结论凝血酶和PAR-1蛋白的表达增加可能与脑缺血冉灌注损伤的发病机制有关;凝血酶可能通过激活PAR-1参与了再灌注损伤的病理生理过程。     

大鼠局灶性脑缺血再灌注中1-磷酸鞘氨醇受体1的表达变化

目的 观察大鼠局灶性脑缺血再灌注模型1-磷酸鞘氨醇受体1(S1P1)的变化,探索S1P1在脑缺血再灌注损伤中的作用.方法 雄性Wistar大鼠,随机分成假手术组、缺血2h再灌注3h组、6h组、12h组、24h组、24h+安慰剂组和24h+FTY720组.应用"线栓法"实现大鼠右侧大脑中动脉闭塞,2h后拔出线栓进行再灌注,并在相应时间点处死大鼠.再灌注24h+安慰剂组和再灌注24h+FTY720组大鼠于再灌注前10min经尾静脉注入安慰剂或S1P受体激动剂FTY720[1mg/(kg·体重)].利用免疫组化方法观察S1P1蛋白表达水平的变化,对再灌注24h+安慰剂组和再灌注24h+FTY720组大鼠进行神经功能评分、梗死体积测定和TUNEL阳性细胞计数.结果 与假手术组相比,缺血再灌注组大鼠梗死灶周围区皮质S1P1的蛋白表达水平明显升高(P<0.05),开始于再灌注后3h,12h达到高峰,24h开始下降.FTY720显著缩小梗死体积,改善神经功能评分,减少TUNEL阳性细胞数量.结论 S1P1在脑缺血再灌注过程中激活,减轻缺血再灌注损伤,发挥脑保护作用.     

Sphingosine kinase-1 expression correlates with poor survival of patients with glioblastoma multiforme: roles of sphingosine kinase isoforms in growth of glioblastoma cell lines

Sphingosine-1-phosphate is a bioactive lipid that is mitogenic for human glioma cell lines by signaling through its G protein-coupled receptors. We investigated the role of sphingosine-1-phosphate receptors and the enzymes that form sphingosine-1-phosphate, sphingosine kinase (SphK)-1, and -2 in human astrocytomas. Astrocytomas of various histologic grades expressed three types of sphingosine-1-phosphate receptors, S1P1, S1P2, and S1P3; however, no significant correlation with histologic grade or patient survival was detected. Expression of SphK1, but not SphK2, in human astrocytoma grade 4 (glioblastoma multiforme) tissue correlated with short patient survival. Patients whose tumors had low SphK1 expression survived a median 357 days, whereas those with high levels of SphK1 survived a median 102 days. Decreasing SphK1 expression using RNA interference or pharmacologic inhibition of SphK significantly decreased the rate of proliferation of U-1242 MG and U-87 MG glioblastoma cell lines. Surprisingly, RNA interference to knockdown SphK2 expression inhibited glioblastoma cell proliferation more potently than did SphK1 knockdown. SphK knockdown also prevented cells from exiting G1 phase of the cell cycle and marginally increased apoptosis. Thus, SphK isoforms may be major contributors to growth of glioblastoma cells in vitro and to aggressive behavior of glioblastoma multiforme.     

Multifaceted roles of sphingosine‐1‐phosphate: How does this bioactive sphingolipid fit with acute neurological injury?

Sphingosine-1-phosphate (Sph-1-P) is an essential bioactive sphingolipid metabolite that has currently become the focus of intense interest. Sph-1-P is generated by the enzyme sphingosine kinase (SphK) in response to diverse stimuli, including growth factors, cytokines, and G-protein-coupled receptor (GPCR) agonists. Its precursor, sphingosine (Sph), is produced from the precursor ceramide (Cer) via a ceramidase (CDase) that is released from membrane sphingomyelin (SPM) by sphingomyelinases (SMase). Accumulating evidence indicates that Sph-1-P is the key regulatory lipid involved in the metabolism of sphingolipids and is involved in the control of numerous aspects of cell physiology, including mitogenesis, differentiation, migration, and apoptosis. These actions of Sph-1-P are mediated by a family of high-affinity S1P receptors, named S1P1-5, which are coupled differentially via G(i), G(q), G(12/13), and Rho to multiple effector systems, including adenylate cyclase, phospholipases C (PLC) and D (PLD), extracellular-signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, and nonreceptor tyrosine kinases. In this Review, we accumulate available evidence implying that sphingolipid signaling may represent a novel neuroprotective target to counteract the pathophysiology of acute brain and spinal cord injury in regard to apoptotic cell death mechanisms, mitochondrial dysfunction, lipid hydrolysis, and oxidative damage mechanisms. Furthermore, we discuss how Sph-1-P agonist approaches might be expected to increase the resistance of the central nervous system to injury by promoting neurotrophic activity, neurogenesis, and angiogenesis. On the other hand, antagonists of certain Sph-1-P-related activity might possess proregenerative effects via promotion of neurite growth and inhibition of astrogliotic scarring.     

沉默信息调节蛋白1在缺血性脑损伤中的神经保护作用

近年来，沉默信息调节蛋白1（silent information regulator protein 1，SIRT1）作为依赖NAD+ 的组蛋白去乙酰化酶被广泛地研究。SIRT1存在于机体各组织细胞中，通过去乙酰化修饰，调节细胞 的多种生理过程，在能量守恒、细胞氧化、衰老及凋亡等方面发挥重要作用。目前认为，SIRT1在缺血 性脑损伤中起到神经保护作用，可能通过调控细胞能量代谢，抗炎性反应、抗细胞凋亡等方面发挥 作用。本文主要综述了SIRT1在缺血性脑损伤中的神经保护作用。     

Involvement of the Wnt signaling pathway and cell apoptosis in the rat hippocampus following cerebral ischemia/reperfusion injury

We investigated the role of the Wnt signaling pathway in cerebral ischemia/reperfusion injury by examining β-catenin and glycogen synthase kinase-3β protein expression in the rat hippocampal CA1 region following acute cerebral ischemia/reperfusion. Our results demonstrate that cell apoptosis increases in the CA1 region following ischemia/reperfusion. In addition, β-catenin and glycogen synthase kinase-3β protein expression gradually increases, peaking at 48 hours following reperfusion. Dickkopf-1 administration, after cerebral ischemia/reperfusion injury, results in decreased cell apoptosis, and β-catenin and glycogen synthase kinase-3β expression, in the CA1 region. This suggests that β-catenin and glycogen synthase kinase-3β, both components of the Wnt signaling pathway, participate in cell apoptosis following cerebral ischemia/reperfusion injury.     

葛根素对小鼠脑缺血再灌注损伤的神经保护作用及机制研究

目的 观察葛根素对脑缺血再灌注小鼠的神经保护作用并探讨其对雌激素受体（estrogen receptor, ER）及缺氧诱导因子-1（hypoxia inducible factor-1,HI F-1）表达及相关炎症因子释放的影响。 方法 C57BL小鼠随机分为假手术组、溶剂对照组以及葛根素低剂量组（100 mg·kg-1）、中剂量 组（250 mg·kg-1）和高剂量组（500 mg·kg-1）,采用线栓法制备小鼠大脑中动脉栓塞模型（middle cerebral artery occlusion,MCAO）,缺血2 h,再灌注24 h后观察葛根素对损伤后脑梗死体积、含水 量、神经功能评分等指标的影响。根据再灌注不同时间点,溶剂对照组又分为2 h、6 h、12 h、24 h共 4个亚组,分别在相应时间点采用蛋白质免疫印迹技术测定脑组织中ER-α及HIF-1α的变化情况。取 变化最显著的缺血2 h再灌注12 h这一时间点测定葛根素对ER-α及HIF-1α表达的影响,并通过酶联 免疫吸附技术测定葛根素在这一时间点对下游炎症因子如肿瘤坏死因子α（tumor necrosis factor-α, TNF-α）、白细胞介素1β（interleukin-1β,IL-1β）和白细胞介素6（interleukin-6,IL-6）的调节作用。 结果 相比溶剂对照组,低、中和高剂量组葛根素均能降低缺血2 h再灌注24 h小鼠的脑梗死体 积[低剂量（29.6±3.6）%,中剂量（15.2±3.9）%,高剂量（8.2±2.1）% vs 对照组（39.3±5.0）%] 和脑含水量[低剂量（84.9±8.8）%,中剂量（83.7±8.2）%,高剂量（80.9±8.7）% vs 对照组 （85.3±10.2）%],差异有统计学意义。对于脑缺血2 h再灌注12 h小鼠,中、高剂量葛根素组较溶剂对 照组ER-α水平升高,HI F-1α水平降低,差异有统计学意义;中、高剂量葛根素组TNF-α（[ 420.7±27.2） μg·g-1,（379.6±23.9）μg·g -1] 、I L-1β[（211.8±19.2）μg·g-1,（182.4±13.5）μg·g -1]和I L- 6（[ 111.2±9.1）μg·g-1,（104.1±12.4）μg·g -1]水平较溶剂对照组[TNF-α（505.8±36.7）μg·g-1;IL-1β （291.6±21.8）μg·g-1;IL-6（138.4±11.7）μg·g-1] 下降,差异有统计学意义。 结论 葛根素在一定剂量范围内可降低脑缺血再灌注小鼠病变脑组织的含水量,减小梗死体积,其 作用机制可能与激活ER-α、抑制HI F-1α表达并抑制相关炎症因子TNF-α、IL-1β和IL-6的释放有关。     

急性缺血性卒中患者血清miRNA-148a表达水平检测及其临床价值预探索

目的 探讨急性缺血性卒中（acute i schemi c stroke,AI S）患者血清mi RNA-148a的表达水平及其临床 价值。 方法 收集42例AIS患者和42例健康者的外周血血清样本,采用实时定量聚合酶链反应技术测定 miRNA-148a的表达水平。绘制miRNA-148a对AIS诊断的受试者工作特征（receiver operating characteristic, ROC）曲线,并分析mi RNA-148a与临床资料的相关性。从基因表达综合数据库下载GSE55937数据集对 AIS患者的miRNA-148a水平进行进一步验证,并采用生物信息学方法预测其靶基因及生物功能。 结果 AIS患者发病12 h内的miRNA-148a相对表达量低于健康对照组（0.76±0.23 vs 1.02±0.21, P <0.001）。mi RNA-148a诊断AI S的ROC曲线下面积为0.79（95%CI 0.70～0.89,P <0.001）。Spearman相 关性检验表明,mi RNA-148a水平与AIS患者的脑梗死面积（r =-0.34,P =0.03）和hs-CRP水平（r =- 0.43,P =0.005）负相关。在GSE55937数据集中,mi RNA-148a相对表达量在AIS组也明显低于对照组 （1.93±0.46 vs 2.52±1.00,P =0.011）,其对AIS诊断的ROC曲线下面积为0.69（95%CI 0.54～0.84, P =0.022)。生物信息学方法共预测到58个miRNA-148a的靶基因,包括WNT10B、DNMT1等。这些靶基因 主要涉及的分子机制包括调控细胞凋亡、FoxO信号通路、PI3K-Akt通路等。 结论 AIS患者发病早期的血清miRNA-148a水平降低,可能涉及细胞凋亡和FoxO、PI3K-Akt等信号通 路,提示mi RNA-148a可能在AIS的诊断及病情评估方面具有一定参考价值。     

The role of Rho/Rho-kinase pathway and the neuroprotective effects of fasudil in chronic cerebral ischemia

The Rho/Rho-kinase signaling pathway plays an important role in cerebral ischemia/reperfusion injury. However, very few studies have examined in detail the changes in the Rho/Rho-kinase signaling pathway in chronic cerebral ischemia. In this study, rat models of chronic cerebral ischemia were established by permanent bilateral common carotid artery occlusion and intragastrically administered 9 mg/kg fasudil, a powerful ROCK inhibitor, for 9 weeks. Morris water maze results showed that cognitive impairment progressively worsened as the cerebral ischemia proceeded. Immunohistochemistry, semi-quantitative RT-PCR and western blot analysis showed that the expression levels of Rho-kinase, its substrate myosin-binding subunit, and its related protein alpha smooth muscle actin, significantly increased after chronic cerebral ischemia. TUNEL staining showed that chronic cerebral ischemia could lead to an increase in neuronal apoptosis, as well as the expression level of caspase-3 in the frontal cortex of rats subjected to chronic cerebral ischemia. Fasudil treatment alleviated the cognitive impairment in rats with chronic cerebral ischemia, and decreased the expression level of Rho-kinase, myosin-binding subunit and alpha smooth muscle actin. Furthermore, fasudil could regulate cerebral injury by reducing cell apoptosis and decreasing caspase-3 expression in the frontal cortex. These findings demonstrate that fasudil can protect against cognitive impairment induced by chronic cerebral ischemia via the Rho/Rho-kinase signaling pathway and anti-apoptosis mechanism.     

Dexmedetomidine (Dex) exerts protective effects on rat neuronal cells injured by cerebral ischemia/reperfusion via regulating the Sphk1/S1P signaling pathway

AimTo investigate the influence of dexmedetomidine (Dex) on cerebral ischemia/reperfusion (I/R)-injured rat neuronal cells by regulating the Sphk1/S1P pathway.MethodsThe rats were divided into the following groups, with 18 rats in each group categorized on the basis of random number tables: sham (Sham), I/R (I/R), Dex, Sphk1 inhibitor (PF-543), and Dex together with the Sphk1 agonist phorbol-12-myristate-13-acetate (Dex+PMA). The neurological functions of the rats were assessed by the Longa scoring system at 24 h post reperfusion. The area of brain infarction was inspected using 2,3,5-triphenyltetrazolium chloride staining, and the water content of brain tissue was determined by the dry-wet weight method. The morphology of neurons in the CA1 region of the rat hippocampus was inspected using Nissl staining, while the apoptosis of neurons in this region was detected by terminal-deoxynucleotidyl transferase mediated nick end labeling staining. The Sphk1 and S1P protein levels were determined by immunofluorescence and western blotting, respectively.ResultsCompared to the I/R group, rats in the Dex, PF-543, and Dex+PMA groups had a significantly lower neurological function score, as well as lower brain water content and a decreased infarction area. Moreover, the apoptotic index of the neurons and the Sphk1 and S1P levels in the hippocampal CA1 region were significantly lower in these groups (p<0.05). PMA, an agonist of Sphk1, was able to reverse the protective effects of Dex on I/R-induced neuronal cell injury.ConclusionDex could protect cerebral I/R-induced neuronal cell injury by suppressing the Sphk1/S1P signaling pathway.     

Changes of hypoxia-inducible factor-1 signaling and the effect of cilostazol in chronic cerebral ischemia

Hypoxiainducible factor1 and its specific target gene heme oxygenase1, are involved in acute cerebral ischemia. However, very few studies have examined in detail the changes in the hy poxiainducible factor1/heme oxygenase1 signaling pathway in chronic cerebral ischemia. In this study, a rat model of chronic cerebral ischemia was established by permanent bilateral common carotid artery occlusion, and these rats were treated with intragastric cilostazol （30 mg/kg） for 9 weeks. Morris water maze results showed that cognitive impairment gradually worsened as the cerebral ischemia proceeded. Immunohistochemistry, semiquantitative PCR and western blot analysis showed that hypoxiainducible factorla and heme oxygenase1 expression levels in creased after chronic cerebral ischemia, with hypoxiainducible factorla expression peaking at 3 weeks and heme oxygenase1 expression peaking at 6 weeks. These results suggest that the elevated levels of hypoxiainducible factorla may upregulate heine oxygenase1 expression fol lowing chronic cerebral ischemia and that the hypoxiainducible factor1/heme oxygenase1 sig naling pathway is involved in the development of cognitive impairment induced by chronic cerebral ischemia. Cilostazol treatment alleviated the cognitive impairment in rats with chronic cerebral ischemia, decreased hypoxiainducible factorla and heme oxygenase1 expression levels, and reduced apoptosis in the frontal cortex. These findings demonstrate that cilostazol can protect against cognitive impairment induced by chronic cerebral ischemic injury through an antiapoptotic mechanism.     

肉苁蓉总苷对清醒小鼠脑缺血再灌注致海马CA1区脑组织损伤的保护作用

目的 探讨肉苁蓉总苷(GCs)对脑缺血再灌注所致清醒小鼠海马CA1区脑组织损伤的保护作用。方法 结扎小鼠右侧颈总动脉建立脑缺血及脑缺血再灌注模型，动态观察GCs对脑缺血3小时再灌注24及48小时两个时点脑梗死范围百分比、脑缺血3小时再灌注24小时海马CA1区脑组织病理变化及脑细胞凋亡情况的影响。结果 脑缺血及脑缺血再灌注后脑梗死范围百分比明显增加；海马CA1区脑细胞密度降低，细胞皱缩明显，胞浆染色较深，核染色质凝聚，凋亡神经细胞明显增多；与缺血组相比，缺血再灌注组损伤加重。GCs可促进上述各项指标的恢复，显著降低脑梗死范围百分比，减轻脑组织病理损伤，抑制脑细胞凋亡。结论 GCs对脑缺血再灌注小鼠脑组织具有保护作用，其机制可能与抗氧化及抗脑细胞凋亡作用有关。