水通道蛋白-4 mRNA沉默可抑制离体缺氧星形胶质细胞水通道蛋白-4的表达

目的:研究水通道蛋白-4(AQP4) mRNA沉默对体外缺氧星形胶质细胞AQP4表达的影响.方法: 用氯化钴诱导体外星形胶质细胞缺氧,建立AQP4 mRNA沉默缺氧星形胶质细胞模型.随机分为正常组、对照组、缺氧组和干扰组,观察星形胶质细胞形态,免疫细胞化学、荧光定量PCR、免疫印迹法检测AQP4 mRNA 及蛋白表达....     

水通道蛋白在胶质细胞的表达及其意义

20世纪80年代,美国学者Peter Agre发现质膜上存在一类介导水快速跨膜转运的膜蛋白,这类膜蛋白被称作水通道蛋白.已有大量研究发现胶质细胞表达的水通道蛋白对神经系统疾病的发生有重要作用.本文综述水通道蛋白在胶质细胞的表达定位及其意义,为中枢和周围神经系统疾病的诊断和治疗提供新的靶点.     

miR-29a调控水通道蛋白4抑制过氧化氢诱导的星形胶质细胞凋亡

背景：一些研究已经证实了miR-29a、水通道蛋白4在星形胶质细胞损伤过程中的作用,但其是否存在相互作用以及分子机制尚未见报道。目的：研究miR-29a调控水通道蛋白4表达对过氧化氢诱导星形胶质细胞损伤的影响。方法：(1)以小鼠原代培养的星形胶质细胞为研究对象,用不同浓度的过氧化氢诱导小鼠星形胶质细胞损伤反应,细胞分为对照组、过氧化氢组、过氧化氢+空载体组、过氧化氢+miR-29a过表达组。采用MTT法检测小鼠星形胶质细胞存活率;Western blot法检测小鼠星形胶质细胞凋亡相关蛋白(Bcl-2、Bax、cleaved-Caspase-3)、水通道蛋白4和胶质纤维酸性蛋白的蛋白表达水平;实时定量PCR检测小鼠星形胶质细胞中miR-29a的表达水平;流式细胞仪检测小鼠星形胶质细胞凋亡水平。(2)将12只雌性BALB/c小鼠随机分为空载体组、过表达miR-29a组,每组6只。制备小鼠T₁₀脊髓撞击损伤动物模型,建模后分别注射以下重组慢病毒(空载体、miR-29a过表达载体)。术后第7天,采用免疫组织荧光染色检测小鼠脊髓损伤部位水通道蛋白4和胶质纤维酸性蛋白表达水平...     

蛋白脂蛋白在两型星形胶质细胞和少突胶质细胞中的表达

目的:探讨蛋白脂蛋白(PLP)在分化成熟的两型星形胶质细胞和少突胶质细胞中的表达。方法:用激光共聚焦双重免疫荧光标记技术检测PLP在分化成熟的两型星形胶质细胞和少突胶质细胞中的表达情况。结果:在O-2A谱系来源的成熟2型星形胶质细胞和少突胶质细胞中PLP抗体标记为阳性,而在T1A谱系来源的成熟1型星形胶质细胞中则未检测到PLP的表达,从而在蛋白质水平验证本室研究两型星形胶质细胞基因表达谱差异基因芯片结果中PLP mRNA在T2A中高表达,而在T1A中低表达的现象。结论:PLP等脂代谢相关基因可能在O-2A谱系发生和分化过程中起重要作用,O-2A谱系与神经髓鞘发生以及脑内脂质代谢内在机制密切相关。     

水通道蛋白与神经系统疾病关系的研究进展

20世纪80年代,美国学者Peter Agre发现质膜上有构成水通道的膜蛋白,这种膜蛋白被命名为水孔蛋白或水通道蛋白(AQP)。水通道蛋白的发现,揭示了水可快速穿膜流动的机制,而且通过研究发现,水通道蛋白与人体多种疾病的发生有关,如神经系统、肾脏、肠道、眼以及耳鼻喉等的疾病。近年来,人们针对水通道蛋白在各种疾病中的生理、病理作用进行了大量的研究。我们着眼于水通道蛋白与神经系统疾病间的关系,重点对在神经系统疾病中起关键作用的AQP-1和AQP-4的研究新进展进行综述。     

水通道蛋白4和人星形胶质细胞瘤在体内增殖和瘤周水肿的相关性研究

目的：研究水通道蛋白4（aquaporin-4, AQP4）和人星形胶质细胞瘤在体内增殖和瘤周水肿的相关性。方法建立人星形胶质细胞瘤裸鼠模型; EdU法检测细胞增殖;免疫组织化学法检测肿瘤组织内CD34阳性细胞表达,检测肿瘤组织微血管密度;免疫印迹法测AQP4蛋白表达;以人脑正常星形胶质细胞为阴性对照。结果细胞皮下注射一周后可见肿瘤长出, EdU法检测肿瘤增殖能力随肿瘤恶性程度增加而增大,免疫组织化学检测提示高度恶性组较低度恶性组具备更高的微血管密度, AQP4蛋白表达随恶性程度增加而增加。结论水通道蛋白4的表达水平和人星形细胞瘤增殖和瘤周水肿程度密切相关。     

大鼠脑内星形胶质细胞对渗透压改变的反应及其和神经元的相互关系

为观察大鼠在饮用 3 % Na Cl溶液 2 d和 5 d时的脑内星形胶质细胞的反应变化及相互关系。本文应用免疫组织化学三重标记法 ,在脑原位切片同时显示 FOS、胶质原纤维酸性蛋白、酪氨酸羟化酶 (或加压素 )的表达、相互关系及分布规律。结果显示 :(1)实验组大鼠脑内孤束核、味觉核、臂旁核、蓝斑、导水管周围灰质的腹外侧区、上丘中灰层、下丘脑室旁核外侧大细胞部、视上核、和穹隆下器同时出现 FOS阳性神经元胞核和胶质原纤维酸性蛋白阳性星形胶质细胞。 (2 )在孤束核、蓝斑、下丘脑室旁核外侧大细胞部和视上核出现酪氨酸羟化酶阳性神经元 ,在下丘脑室旁核外侧大细胞部、下丘脑室旁核腹侧部和视上核等出现加压素阳性神经元。(3 )在孤束核、蓝斑、或下丘脑室旁核外侧大细胞部、视上核的三重免疫组化染色切片上见到胶质原纤维酸性蛋白阳性星形胶质细胞包绕 FOS阳性和酪氨酸羟化酶阳性 (或加压素阳性 )神经元 ,形成复合体。提示 :脑内相关核团内的星形胶质细胞与神经元共同参与对渗透压的调节 ,并以神经元—星形胶质细胞复合体作为功能单位     

水通道蛋白1、5在星形细胞瘤中的表达变化

目的:观察水通道蛋白1、5(AQP1、5)在人不同病理级别星形细胞瘤组织中的表达差异,探讨星形细胞瘤增殖、生长的分子机制.方法:收集人各个病理级别星形细胞瘤标本55例,以肿瘤周围相对正常脑组织作为对照,采用H-E染色诊断分级,石蜡切片免疫组织化学、免疫印迹分析及逆转录聚合酶链式反应观察AQP1、5及其mRNA的表达变化.结果:与正常脑组织相比,人星形胶质瘤组织中AQP1及其mRNA表达上调,随着星形细胞瘤病理级别的升高,AQP1及其mRNA表达增强,胶质母细胞瘤组织表达最强烈;而AQP5及其mRNA仅在高恶性星形细胞瘤组织中表达增强.结论:AQP1在人星形细胞瘤组织中表达与其病理级别相关,而AQP5仅在人高恶性星形细胞瘤组织中表达增强,提示不同病理级别胶质瘤组织中AQP的表达规律不尽相同.     

桩蛋白在两型星形胶质细胞及神经元中的差异表达

目的:观察桩蛋白在大鼠两型星形胶质细胞及神经元中的差异表达情况。方法:通过细胞培养并结合免疫荧光和RT-PCR方法,观察了桩蛋白的mRNA及蛋白在大鼠两型星形胶质细胞T1A和T2A以及神经元中的表达。结果:RT-PCR显示体外培养的T1A表达桩蛋白mRNA,而T2A和神经元未表达桩蛋白mRNA;免疫荧光染色显示桩蛋白主要分布于T1A的胞浆及突起中。结论:桩蛋白在T1A中表达,但未表达于T2A和神经元中;本实验结果为进一步研究桩蛋白在T1A中的生物学作用奠定了基础。     

Relationship between anxiety and physical traits of facial expressions

The purpose of this study is to investigate correlations between anxiety and physical traits of facial expressions. In this study, subjects were divided into two groups on the basis of MAS (manifest anxiety scale), and were taken pictures under three different conditions. In Analysis I, we examined how facial expressions differ between high-anxiety and low-anxiety groups. The results showed that facial expressions differed between two groups especially in mouth, left half of the face, and asymmetry of the face. In Experiment I and II, we investigated whether human beings could identify one's anxiety trait and apparent anxiety in facial expressions only on the basis of its facial expressions. The results showed that one's anxiety trait and apparent anxiety could be detected through the mouth. From these results, human beings can recognize one's anxiety through its facial expressions.     

乳腺癌VEGF、MMP-9及COX-2蛋白表达与淋巴道转移和血管生成的相关性

目的 通过检测血管内皮细胞生长因子(VEGF)、基质金属蛋白酶-9(MMP-9)、环氧化酶-2(COX-2)在乳腺癌细胞中的表达情况来探讨它们与乳腺癌淋巴结转移和微血管密度(MVD)的关系.方法 采用免疫组化SP法检测74例乳腺浸润癌(有淋巴结转移者39例,无淋巴结转移者35例)中VEGF、MMP-9、COX-2和CD34的表达,并用多因素Cox比例风险模型分析患者的预后.结果 VEGF、MMP-9、COX-2的表达与MVD值在淋巴结转移组与无转移组之间的差异均具有显著性(P＜0.05),与乳腺癌淋巴结转移呈正相关;VEGF、MMP-9、COX-2蛋白表达与MVD值呈正相关(P＜0.05);COX-2的表达随着乳腺癌病理分级的增高而增强;MVD值高者生存时间短.结论 乳腺癌VEGF、MMP-9、COX-2蛋白表达与其淋巴道转移和MVD有关,检测这几种蛋白表达将有助于判断乳腺癌的转移潜能、血管生成能力及预后.     

Volume changes induced by osmotic stress in freshly isolated rat hippocampal neurons

 The degree to which osmotic stress changes the volume of mammalian central neurons has not previously been determined. We isolated CA1 pyramidal cells and measured cell volume in four different ways. Extracellular osmolarity (π_o) was lowered by omitting varying amounts of NaCl and raised by adding mannitol; the extremes of π_o tested ranged from 134 to 396 mosm/kg. When π_o was reduced, cell swelling varied widely. We distinguished three types of cells according to their response: ”yielding cells” whose volume began to increase immediately; ”delayed response cells” which swelled after a latent period of 2 min or more; and ”resistant cells” whose volume did not change during exposure to hypo-osmotic solution. When π_o was raised, most cells shrank slowly, reaching minimal volume in 15–20 min. We observed neither a regulatory volume decrease nor an increase. We conclude that the water permeability of the membrane of hippocampal CA1 pyramidal neurons is low compared to that of other cell types. The mechanical support of the plasma membrane given by the cytoskeleton may contribute to the resistance to swelling and protect neurons against swelling-induced damage. Received: 16 September 1997 / Received after revision: 22 June 1998 / Accepted: 30 June 1998     

Evidence that pericytes regulate aquaporin-4 polarization in mouse cortical astrocytes

Aquaporin-4 (AQP4) water channels are concentrated in astrocytic endfoot membranes at the brain–blood and brain–cerebrospinal fluid interfaces. The mechanisms underpinning the polarized distribution of AQP4 are poorly understood. Here we tested the hypothesis that pericytes regulate AQP4 anchoring to perivascular astrocytic endfoot membranes. AQP4 immunofluorescence of brain sections obtained from novel transgenic double reporter mice expressing enhanced green fluorescent protein (eGFP) in astrocytes and Discoma Red (DsRed) in pericytes revealed strong AQP4 signal in astrocytic processes adjacent to pericytes. Quantitative immunogold analysis of C57BL/6 mice showed that the AQP4 expression was higher in endfoot membranes abutting pericytes than in those facing endothelial cells. Similar findings were made for α-syntrophin, a member of the dystrophin-associated protein complex (DAPC). The enrichment of α-syntrophin in membranes ensheathing pericytes persisted after Aqp4 gene deletion. Our data support the concept that pericytes regulate AQP4 polarization.     

Immunolocalization of aquaporin-9 in rat hepatocytes and Leydig cells

The aquaporin (AQP)-9 gene was recently isolated from human and rat liver cDNA libraries as a member of the water channel family for water and neutral solutes. Although the expression of AQP9 mRNA has been demonstrated in several organs including the liver and testis by Northern blot analysis, the cellular and subcellular localization of the AQP9 protein remains unclear. In the present light and electron microscopic immunohistochemical study, the localization of the AQP9 immunoreactivity was examined in fifteen kinds of rat organs using an antibody against rat AQP9 synthetic peptide. The antibody immunostained a major band of approximately 33 kDa in the liver by Western blot analysis. Immunoreactivity for AQP9 was found exclusively in the liver and testis among the organs examined. In the liver, positive staining appeared selectively along the space of Disse. Immunoelectron microscopy confirmed the localization of AQP9 on the surface of hepatocyte microvilli facing the space of Disse. In the testis, the plasma membrane of Leydig cells located between seminiferous tubules was conspicuously immunoreactive to the antibody. Intense mRNA expression was detected in the liver and testis but not in other organs by ribonuclease protection assay. These findings suggest a specific role for AQP9 in the transport of water and non-charged solutes in hepatocytes and Leydig cells.     

Hypertonic saline ameliorates cerebral edema through downregulation of aquaporin-4 expression in the astrocytes

Osmotherapy with 10% hypertonic saline (HS) alleviates cerebral edema through osmotic force. Aquaporin-4 (AQP4) has been reported to be implicated in the pathogenesis of cerebral edema resulting from a variety of brain injury. This study aimed to determine if 10% hypertonic saline ameliorates cerebral edema through downregulation of AQP4 expression in the perivascular astrocytes in the ischemic cerebral edema. Adult male Sprague–Dawley (SD) rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO) and treated with a continuous i.v. infusion of 10% HS. Brain water content (BWC) analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats was attenuated after 10% HS treatment. This was coupled with the reduction of neuronal apoptosis in the peri-ischemic brain tissue. Concomitantly, downregulated expression of AQP4 in the perivascular astrocytes after 10% HS treatment was observed. Our results suggest that in addition to its osmotic force, 10% HS exerts anti-edema effects possibly through downregulation of AQP4 expression in the perivascular astrocytes. The reduction of brain edema after 10% HS administration can prevent ischemic brain damage.