水通道蛋白-4在大鼠甲状腺中的表达

目的:观察水通道蛋白-4(AQP4)在甲状腺滤泡细胞的表达和分布特点,为研究甲状腺内分泌及调节机制提供形态学基础。方法:利用免疫组织化学、免疫荧光组织化学和原位杂交组织化学技术,检测大鼠AQP4及其mRNA在甲状腺滤泡上皮细胞的表达。结果:免疫组织化学和免疫荧光组织化学显示,AQP4在甲状腺滤泡上皮细胞膜上有表达,而在上皮细胞基底面和管腔面表达更为明显;原位杂交组织化学显示AQP4 mRNA在上皮细胞中表达明显。结论:AQP4在甲状腺的表达和分布特点,提示其参与了甲状腺素的合成和分泌过程中渗透压的精细调节作用。     

水通道蛋白4在大鼠脑垂体中的表达

目的：研究水通道蛋白4(AQP4)及其mRNA在脑垂体中的表达,探讨其在脑垂体激素分泌过程中的作用。方法：应用免疫组织化学和原位杂交技术,观察成年Wistar大鼠脑垂体中AQP4及其mRNA的正常分布。结果：AQP4及其mRNA在成年大鼠神经垂体的垂体细胞上表达呈阳性,分布在毛细血管窦周围的垂体细胞表达尤为强烈。腺垂体的所有细胞均有AQP4的表达,胞质中AQP4 mRNA表达呈阳性。中间叶所有细胞AQP4及其mRNA的表达呈弱阳性,其中滤泡星形细胞表达较内分泌细胞强烈。结论：AQP4广泛分布于脑垂体的各种组织细胞表面,可能在垂体激素的正常分泌过程中起重要的调节作用。     

水通道蛋白-4在实验性脊髓损伤大鼠的表达

为了观察大鼠脊髓损伤后水通道蛋白4(AQP 4)的表达和对后肢功能的影响,本实验建立Allen脊髓损伤动物模型,于术后1、3、7、14和21d分别对大鼠进行了BBB评分检查后肢功能,处死动物后应用免疫组织化学技术检测脊髓组织内AQP 4的表达,用图像分析仪对脊髓损伤后神经组织的AQP 4的变化进行了定量分析。结果表明:脊髓损伤后第1d,在脊髓损伤组受损伤脊髓灰质和白质中均可见到AQP 4的表达明显增加;第3d时均达到高峰。在第7、14、和21d,AQP 4的表达与对照组均有显著性差异(P<0. 01)。本研究结果提示:脊髓损伤后大鼠脊髓组织中AQP 4的表达显著增加。     

脊髓缺血再灌注损伤对大鼠水通道蛋白4表达的影响

目的:在整体水平研究脊髓缺血再灌注损伤对大鼠水通道蛋白4表达水平的影响.方法:SD大鼠72只随机分为空白组、假手术组和SCⅡ组,每组24只.建立大鼠脊髓缺血再灌注损伤模型,并于1、3、5、7天四个时间点分别处死6只.BBB评分评价神经功能,Western blot和免疫荧光方法检测AQP4的表达情况.结果:空白对照组和假手术组在不同时间点的BBB评分均为21分,SCⅡ组的BBB评分在1天时最低,随时间推移逐渐增加,3天明显优于1天(P＜0.05),5天明显优于3天(P＜0.05),5天明显优于7天(P＜0.05).Western blot在34 kD及43 kD分子量处可见特异性条带,SCⅡ组早期AQP4的表达水平显著下降,即在1、3、5、7天四个时间点AQP4的表达显著低于空白对照组和假手术组,但呈逐渐增加趋势;在7天仍显著低于正常空白组和假手术组(P＜0.05).免疫荧光检测AQP4的表达变化趋势与Western blot的检测结果相似.结论:SCⅡ存在AQP4低表达,这可能是造成SCⅡ神经功能障碍的重要原因.     

水通道蛋白4在大鼠眼球中的表达

目的从转录和翻译水平观察水通道蛋白4(AQP4),在正常Wistar大鼠眼球中的表达,为研究眼球中液体转运机制提供形态学基础。方法采用免疫组织化学SABC法和原位杂交技术。结果所测大鼠眼球呈较强的AQP4免疫反应阳性,角膜上皮细胞、虹膜色素上皮细胞、睫状体非色素上皮细胞、晶状体上皮细胞、晶状体纤维细胞、视网膜的内颗粒层、外颗粒层和节细胞层的细胞均为阳性细胞,免疫反应阳性物质主要分布在细胞膜上,胞核呈阴性。原位杂交结果同免疫组织化学染色基本一致,在以上细胞胞浆中均可检测到较强的AQP4 mRNA阳性杂交信号,‘胞核呈阴性。结论AQP4可能在眼球中角膜和晶状体透明性的维持,房水的分泌和调节,视觉的激发和传递等功能活动中起着重要作用。     

脑外伤小鼠海马水通道蛋白-9表达的变化

目的探讨脑外伤小鼠海马水通道蛋白-9(aquaporin 9,AQP9)表达的变化。方法40只Balb/c小鼠随机分为假手术组(10只)和脑外伤组(30只)。脑外伤组依据脑外伤的不同时间点再分6 h、1 d、3 d三个小组,每组10只。免疫组化和Western blot检测各组小鼠海马AQP9蛋白的表达。RT-PCR方法检测各组小鼠海马AQP9 mRNA的表达变化。结果免疫组化和Western blot结果发现,脑外伤组小鼠海马AQP9蛋白表达量明显高于假手术组(P<0.05);RT-PCR结果也发现,脑外伤组小鼠海马AQP9 mRNA表达量明显高于假手术组(P<0.05)。结论脑外伤小鼠海马AQP9表达明显升高。     

水通道蛋白-4在大鼠睾丸和附睾中的表达

目的 观察水通道蛋白-4（AQP4）在雄性大鼠睾丸和附睾的表达及分布特点,为探讨水通道蛋白在睾丸和附睾中的作用提供形态学基础。方法 采用免疫组织化学的方法,检测AQP4在睾丸和附睾的表达分布。结果 AQP4在睾丸中表达于各级生精细胞、支持细胞以及间质细胞中;在附睾管内表达于柱状上皮细胞,且腔面表达更明显。结论 AQP4可能参与了精子的生成及成熟过程,在激素的分泌调节中发挥作用。     

SIRT1对早期脑缺血大鼠水通道蛋白4表达的影响

目的:检测水通道蛋白4(AQP4)及沉默信息调节因子1(SIRT1)在脑缺血大鼠脑组织中的表达变化,探究SIRT1对AQP4的调节作用,明确二者在脑缺血及脑水肿发生发展中的作用。方法:雄性SD大鼠随机分成假手术组(sham组)和脑缺血模型组(MCAO组),其中MCAO组又分为6 h、12 h、24 h和48 h 4个时点组别。采用线栓法阻塞大脑中动脉建立局灶性脑缺血模型,于相应时点进行神经症状评分,Morris水迷宫检测大鼠学习认知功能,TTC染色观察脑梗死体积,干湿重法检测脑含水量的变化,HE染色观察大脑皮层周围组织神经细胞形态学变化,Western blot检测AQP4、SIRT1和基质金属蛋白酶9(MMP-9)的表达情况。结果:与sham组相比较,随着再灌注时间增加,MCAO组大鼠神经功能评分、脑梗死体积、脑组织通透性和脑组织含水量均持续增加,而大鼠学习认知功能则降低显著,HE染色显示脑缺血大脑皮层周围组织神经元细胞形态不规则,数目减少;Western blot实验结果显示AQP4表达水平呈增高趋势,SIRT1表达降低,MMP-9表达增高,MCAO-48 h组与sham组比较差异最明显(P0.01)。结论:脑缺血后,伴随脑组织损伤的加剧,SIRT1和MMP-9信号通路的表达激活影响了AQP4的表达活化,共同参与了脑水肿的形成。     

水通道蛋白-4与脑水肿关系研究进展

脑水肿是指脑组织内的异常水分潴留，使脑体积增大，是多种疾病伴发的一种病理状态。脑水肿的非手术治疗的方法有渗透性利尿、高张盐水，亚低温治疗等，尚没有针对脑水肿分子机制的有效治疗。水通道蛋白（AQP）是膜水通道蛋白家族，为调节跨细胞水平衡的选择性孔道，迄今在哺乳动物中已发现13种水通道蛋白（AQPO-AQPl2）^[1]。     

水通道蛋白-4在早期缺血性脑水肿中的表达

目的：探讨水通道蛋白-4(AQP-4)在早期缺血性脑水肿过程中的表达规律。方法：对大鼠进行大脑中动脉栓塞，于术后15min～24h采用免疫组化、原位杂交和图像分析技术检测AQP-4的表达量，同时用光镜和电镜行病理观察。结果：AQP-4基因和蛋白表达具有一致性。AQP-4表达丰富的部位主要集中在脉络丛、室管膜细胞、海马和梗塞区细胞并在术后15min～lh时段呈线性增加。病理显示此期主要为细胞内水肿，即缺血半暗带。随着时间的延长，AQP-4表达呈缓慢增高趋势。对应的病理改变为血管源性水肿，最后组织坏死。结论：AQP-4表达增强与早期缺血性脑水肿密切相关，它可能是形成超早期细胞内水肿一半暗带的重要因素之一。     

香烟烟雾暴露对幼年大鼠海马DNA甲基化的影响

目的:探讨香烟烟雾暴露对新生大鼠海马细胞DNA甲基化的水平的影响。方法:18只的SD幼年大鼠随机分为对照组(control)、香烟烟雾暴露组(cigarette smoke),香烟烟雾暴露组大鼠进行香烟烟雾暴露30 d,利用商品化试剂盒检测各组大鼠海马组织5’甲基胞嘧啶(5-mC)的变化,real time RT-PCR检测各组大鼠海马DNA甲基转移酶1(DNMT1)、DNA甲基转移酶3a(DNMT3a)及DNA甲基转移酶3b(DNMT3b) mRNA表达水平,Western Blot检测各组大鼠海马DNMT1、DNMT3a及DNMT3b蛋白水平表达。结果:与对照组相比,香烟烟雾暴露可导致大鼠海马5-mC水平增加,海马DNMT1 mRNA和蛋白表达增加。结论:幼年大鼠香烟烟雾暴露会上调海马组织DNMT1的表达,进而增加DNA甲基化水平。     

大鼠肝脏缺血再灌注损伤后水通道蛋白4表达的变化

目的: 通过建立大鼠肝脏缺血再灌注损伤(IRI)模型,观察水通道蛋白 4(AQP4)在肝内胆管细胞的表达变化,并同时检测肝脏功能变化,探讨肝脏IRI 与AQP4表达变化的关系。方法: 建立大鼠肝脏30 min IRI模型。随机将配对动物分为对照和缺血再灌注2 h、1 d、3 d、7 d组,留取血清标本行间接胆红素(IB)、直接胆红素(DB)及丙氨酸氨基转移酶(ALT)指标检测;留取肝脏标本用于HE染色光镜下观察肝脏病理形态学变化、免疫组化染色观察AQP4表达变化, RT-PCR 方法测定 AQP4 mRNA表达变化。结果: (1)肝功能变化:缺血再灌注损伤2 h、1 d、3 d组IB、DB及ALT明显升高,与对照组间比较有显著差异(P<0.05),并于术后第1 d达到最高(P<0.05);以后逐渐降低,术后第7 d恢复正常。(2) 肝脏病理学变化:术后HE染色可见缺血再灌注可造成大鼠肝组织变性、坏死。(3) 免疫组织化学检测肝脏AQP4的变化:缺血再灌注损伤2 h、1 d、3 d组AQP4的表达量较对照组降低(P<0.05),于术后第1 d最低(P<0.05),以后逐渐增高,于术后第7 d恢复正常。(4) 肝脏AQP4 mRNA表达变化:缺血再灌注损伤组2 h、1 d、3 d组AQP4 mRNA表达水平较对照组明显降低(P<0.05),于术后第1 d最低,以后又逐渐升高,于术后第7 d恢复正常。结论: 大鼠肝脏缺血再灌注损伤后可明显引起肝内胆管上皮细胞AQP4的表达降低,术后第1 d最明显,至术后7 d逐渐恢复正常,此种损害与包括胆红素在内的肝功能损害相对应。     

Lactic acid increases aquaporin 4 expression on the cell membrane of cultured rat astrocytes

The water channel protein aquaporin (AQP) may play roles in the homeostasis of water content in the brain and brain edema. One possible mechanism of brain edema is glial swelling due to lactic acidosis associated with ischemia. Here, we investigated the effect of lactic acid on the expression and cellular distribution of AQP 4 in cultured rat astrocytes. After 24h of incubation, the AQP4 expression level increased maximally with 35mM lactic acid. The AQP4 expression levels also increased with hydrochloric acid or acetic acid. In contrast, with sodium lactate, the AQP4 levels did not increase. The increase in AQP4 expression level occurred without a significant increase in AQP4 mRNA expression level by lactic acid. Under the conditions of de novo protein synthesis inhibition with cycloheximide, lactic acid increased the AQP4 expression level. Furthermore, lactic acid increased the AQP4 expression level on the cell surface of the astrocytes, as determined by a cell surface biotinylation assay and immunocytochemical examination. The increase in AQP4 expression level on the cell membrane of astrocytes induced by lactic acid may be a new regulation mechanism of AQP4 in the brain.     

Differential expressions of aquaporin subtypes in astroglia in the hippocampus of chronic epileptic rats

In order to elucidate the roles of aquaporins (AQPs) in astroglial responses, we investigated AQP expressions in the experimental epileptic hippocampus. In control animals, AQP1 protein expression was restricted to the ventricular-facing surface of the choroid plexus. AQP4 was expressed in astrocyte foot processes near blood vessels and in ependymal and pial surfaces in contact with cerebrospinal fluid. AQP9 protein has been detected in cells lining the cerebral ventricles, and in astrocytes. Six to eight weeks after status epilepticus (SE), AQP1 expression was mainly, but not all, detected in vacuolized astrocytes, which were localized in the stratum radiatum of the CA1 region. AQP4 was negligible in vacuolized CA1 astrocytes, although AQP4 immunoreactivity in non-vacuolized astrocytes was increased as compared to control level. AQP9 expression was shown to be mainly induced in non-vacuolized CA1 astrocytes. Therefore, our findings suggest that AQP subunits may play differential roles in various astroglial responses (including astroglial swelling and astroglial loss) in the chronic epileptic hippocampus.     

黄芪皂甙Ⅳ联合骨髓间充质干细胞移植对大鼠脑缺血/再灌注损伤海马神经元凋亡及相关基因表达的影响

目的 探讨黄芪皂甙Ⅳ联合骨髓间充质干细胞(BMSCs)移植对缺血再灌注大鼠海马神经细胞凋亡及Bcl-2、Bax、Caspase-3表达的影响.方法 实验动物随机分为假手术组、模型组、BMSCs组、BMSCs+黄芪组.采用线栓法建立大鼠大脑中动脉缺血(MCAO)模型,BMSCs组、BMSCs+黄芪组分别于建模成功后3 h...     

粒细胞集落刺激因子对血管性痴呆大鼠海马神经细胞凋亡的影响

背景：研究发现,粒细胞集落刺激因子可激活脑内成体神经干细胞,刺激其增殖和分化,还能促进脑内各种神经营养因子分泌,减小脑缺血动物模型的缺血灶,促进慢性脑卒中模型缺失神经功能的长期恢复。 目的：观察粒细胞集落刺激因子对血管性痴呆大鼠海马神经细胞凋亡的作用。 方法：采用永久性双侧颈总动脉结扎法建立大鼠血管性痴呆模型,抽签法随机分为4组：实验组(皮下注射粒细胞集落刺激因子干预治疗)、对照组(注射生理盐水)、假手术组(仅行颈前正中切开,不结扎颈总动脉)。采用Morris水迷宫进行定向航行观察大鼠逃避潜伏期,评价大鼠空间学习记忆能力,TUNEL染色和图像分析大鼠海马神经细胞的凋亡。 结果与结论：对照组和实验组大鼠脑缺血后7 d,大鼠平均逃避潜伏期较假手术组明显延长(P < 0.01),海马组织TUNEL阳性凋亡细胞较假手术组显著增高(P < 0.01),随着时间的延长,14,28 d时大鼠学习记忆功能障碍逐渐加重,相应海马组织TUNEL阳性凋亡细胞逐渐增加。14,28 d时实验组大鼠平均逃避潜伏期比对照组明显缩短,海马组织TUNEL阳性凋亡细胞也较对照组显著减少。说明脑缺血后早期给予外源性粒细胞集落刺激因子有助于减少海马组织神经细胞的凋亡,改善大鼠学习记忆能力。     

The effect of Ginkgo biloba extract on scopolamine-induced apoptosis in the hippocampus of rats

Apoptosis, known as programmed cell death, plays a crucial role in normal development and tissue homeostasis. Apoptosis is also involved in neurodegenerative diseases such as Alzheimer’s disease. Amnesia refers to the loss of memory and can also be a warning sign of neurodegenerative diseases. The antioxidant properties of Ginkgo biloba extract was known previously. Therefore, the aim of this study was to examine the effects of Ginkgo biloba extract on the rat’s hippocampal apoptotic neurons number after Scopolamine based amnesia. Thirty-six adult male Wistar rats were used. Rats were randomly divided into control, sham, protective and treatment groups. The rats in the sham group received only scopolamine hydrobromide (3 mg/kg) intraperitoneally. The rats in the protective and treatment groups received Ginkgo biloba extract (40, 80 mg/kg) for 7 days intraperitoneally before/after scopolamine injection. Then 48 h after the last injection, the brains of rats were withdrawn and fixed with paraformaldehyde, and then, after histological processing, the slices were stained with the TUNEL kit for apoptotic neurons. Data were compared by the ANOVA Post Hoc Tukey test; P < 0.05 was considered significant. Our results showed that Scopolamine (in the sham group) increased significantly the number of apoptotic neurons in all areas of the hippocampus compared with the control. Whereas, Ginkgo biloba extract reduce the neuronal apoptosis in the hippocampus before and/or after encounter with scopolamine. We concluded that pretreatment and treatment injection of Ginkgo biloba extract can have a protective effect for neurons and it can limit apoptosis in all area of the hippocampus.     

The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats

The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01–P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.     

水通道蛋白4在大鼠淋巴性脑水肿中的作用

 目的：研究水通道蛋白4（AQP4）在淋巴性脑水肿（LBE）形成和消散过程中的作用。方法：将大鼠随机分为假手术组和LBE组。采用结扎双侧颈部淋巴管并摘除淋巴结的方法,制作LBE模型。干湿重法检测大鼠大脑皮质含水量,应用免疫荧光组织化学方法及免疫印迹检测在颈淋巴引流阻滞后不同时点AQP4表达的变化情况,并对AQP4表达与脑含水量作相关分析。结果：与假手术组相比,LBE组大鼠脑含水量、AQP4免疫荧光表达阳性细胞数、强度及AQP4蛋白表达在术后3 d均见升高（P<0.05）,7 d升至高峰（P<0.01）,后逐渐降低,且AQP4蛋白表达与脑含水量呈正相关关系（r=0.8024,P<0.05）。结论：AQP4在大鼠LBE的形成和消散过程中起到了重要的作用。