Endothelial nitric oxide synthase (eNOS) is localized to Müller cells in all vertebrate retinas.

The distribution of endothelial nitric oxide synthase immunoreactivity (eNOS-IR) was investigated in the retinas of all phylogenetic vertebrate classes by using a monoclonal eNOS antibody. Confocal light microscopy showed immunoreactive labeling in Müller cells of fish, frog, salamander, turtle, chicken, rat, ground squirrel, and monkey retina. In vascularized retinas (rat, monkey), astrocytes and some blood vessels were also stained. Furthermore, eNOS-IR was localized to axon terminals of turtle and fish horizontal cells. These observations are the first to show the presence of eNOS-IR in Muller glia and horizontal cell structures of the vertebrate retina.     

Alteration of Leukocyte–Endothelial Cell Interaction During Aging in Retinal Microcirculation of Hypertensive Rats

Purpose Hypertension, one of the more common chronic diseases affecting the elderly, has been reported to influence leukocyte–endothelial cell interaction. The leukocyte-mediated inflammatory process contributes to age-related changes in vessels. This study was designed to evaluate age-related changes in leukocyte–endothelial cell interaction in the hypertensive rat retina. Methods Male spontaneous hypertensive rats (SHR; 1.5, 3, 6, 12, and 20 months of age) and age-matched Wistar-Kyoto rats (WKY) were used. The number of accumulated leukocytes was counted in sections of flat-mounted retinal tissue. The expression of intercellular adhesion molecule-1 (ICAM-1) and CD18 (the common β-chain of ICAM-1 ligands) was evaluated. Retinal thickness was evaluated histologically. Results The number of accumulated leukocytes and the expression of ICAM-1 and CD18 increased in the aged retina. The number of leukocytes that accumulated and the expression of CD 18 were significantly higher in the SHR group than in the WKY group (P < 0.01). In addition, retinal thickness decreased with age. Conclusion Leukocyte–endothelial cell interaction increased in the aged retina and these changes were more severe in SHR retina than in WKY retina. This increased interaction was first observed at 3 months, a relatively young age.     

视网膜中的Müller细胞

Müller细胞是视网膜的重要组成部分,除了传统认为其对视网膜神经细胞有支持和营养作用外,目前的研究表明Müller细胞在视网膜神经递质的调节、视网膜中钾离子的调节、视网膜中pH值的调节以及对神经细胞的信号传递方面都发挥了重要的作用。就Müller细胞的生理功能及其在视网膜病理状态下的改变作一综述。     

Müller muscle-conjunctiva resection to correct ptosis in high-risk patients

PURPOSE: Müller muscle-conjunctiva resection could be seen as a relative contraindication in patients with a prior history of a glaucoma filtering procedure, corneal disease, or corneal surgery. The concern centers around the theoretical risk of bleb-related complications or corneal damage from the palpebral conjunctival sutures. Our study aimed to determine whether any bleb- or cornea-related complications arose in patients who underwent Müller muscle-conjunctiva resection for ptosis correction. METHODS: A retrospective chart review was performed on 2 practices of oculofacial plastic surgeons from 2000 to 2006, including patients who had ptosis correction by Müller muscle-conjunctiva resection. Patients with a prior history of a glaucoma filtering procedure, corneal disease, or corneal surgery were identified. Each case was reviewed to determine whether any bleb- or cornea-related complications occurred. The postoperative improvement of ptosis measured by interpalpebral distance or margin reflex distance-1 also was noted. RESULTS: Forty-three patients and 55 eyes with a history of a glaucoma filtering procedure (13 patients/15 eyes), corneal disease (1 patient/1 eye), or corneal surgery (29 patients/39 eyes) who underwent Müller muscle-conjunctiva resection were identified. The average follow-up time was 212.4 days. No bleb-related complications occurred. One patient with a history of Reis-Bücklers dystrophy experienced a corneal abrasion. Fifty-two of 55 patients had objective improvement of their ptosis. CONCLUSIONS: Müller muscle-conjunctiva resection can provide an effective means for ptosis repair in patients with a prior history of a glaucoma filtering procedure, corneal disease, or corneal surgery. One temporary postoperative corneal complication occurred in our series.     

视网膜Müller细胞的培养

Ｍü ｌｌｅｒ细胞参与视网膜的多种生理病理过程，近年来发展起来的Ｍｕｌｌｅｒ细胞培养技术为揭示其机制提供了一条有效途径。本文介绍了Ｍü ｌｌｅｒ细胞的分离培养、纯化、鉴定技术。组织块贴壁培养法及酶消化培养法是目前普遍使用的培养方法。在细胞纯化方面，有毛吸管吸取、机械震荡吹打、速率沉淀、梯度离心等多种方法，而以机械震荡吹打法应用最广。Ｍü ｌｌｅｒ细胞的鉴定以形态学鉴定及免疫组化鉴定为主。     

视网膜Müller细胞的研究进展

Müller细胞是视网膜特化的胶质细胞,它贯穿于视网膜全层,与视网膜神经元、其它胶质细胞、视网膜血管等紧密联系。Müller细胞不但对视网膜正常发育起着决定性作用,而且能支持神经元活动、调节神经递质循环、维持细胞外环境平衡、调节视网膜血管通透性。视网膜Müller细胞代谢障碍将导致视功能丧失、神经元细胞死亡、视网膜水肿等。因此,Müller细胞对维持视网膜的正常生理功能起着重要作用。我们就近年来Müller细胞的研究进展作一综述。     

Responses of Müller glia to retinal injury in adult zebrafish

In an effort to identify the cellular events that enable neuronal regeneration in the vertebrate retina, the identity and characteristics of mitotic and apoptotic cells were examined in lesioned retinas of adult zebrafish. Following lesion a complex spatiotemporal pattern of mitosis was observed, including a delayed entry of Müller glia into the cell cycle. Characteristics of these proliferative Müller glia indicated they might serve as a stem/precursor cell of regenerated retina. The results suggested a model of retinal regeneration in which lesions are filled, in part, by a localized en place cytogenesis within intact retina surrounding the lesion site.     

视网膜Müller细胞透明质酸酶功能分析

目的分析离体培养的视网膜Müller细胞对透明质酸的降解功能。方法提取的Mller细胞来自酶降解的猪后极部视网膜,并以3种不同细胞标记:胶质纤维酸性蛋白、波形蛋白、谷氨酰胺合成酶进行免疫荧光确认。细胞分为4组,其中1组培养液中加入透明质酸,2组培养液中加入透明质酸和抗integrinα2β1抗体,3组培养液中加入透明质酸和抗CD44抗体,4组培养液中未加入其他试剂。细胞预培养后,收集上清液。按配置聚丙烯酰胺凝胶的方法 ,加入透明质酸,不加入十二烷基硫酸钠制作底物胶。样品在底物胶电泳后,凝胶在酶降解缓冲液中培养24h,淋洗后以5g.L-1亮蓝染色、体积分数7%醋酸脱色,观察有无透明质酸降解后形成的脱色条带。结果 93.8%细胞胶质纤维酸性蛋白抗体染色阳性,94.6%细胞波形蛋白抗体染色阳性,88.6%细胞谷氨酰胺合成酶抗体染色阳性。培养的Mller细胞有降解透明质酸的功能,(4组)表现为蓝色背景(透明质酸染色)下的淡白色双条带(透明质酸降解后脱色);将细胞和透明质酸预培养可使脱色条带明显增厚,表现为明亮的白色条块(1组),同时加入透明质酸和integrinα2β1抗体产生相似的白色条块(2组),同时加入透明质酸和CD44抗体使脱色恢复为淡白色双条带(3组)。结论培养的Mller细胞有降解透明质酸的功能,细胞与透明质酸的相互作用明显加强细胞降解透明质酸的功能,CD44抗体可能减弱这种加强作用,integrinα2β1抗体无明显作用。     

兔视网膜Müller细胞原代培养

目的 建立成年兔视网膜Müller细胞体外原代培养方法.方法 运用组织块培养法.分离出成年兔视网膜神经感觉层,剪成1 mm×1 mm大小组织块,置于含有20%胎牛血清的Dulbecco改良Eagle培养液/F12培养,采用倒置相差显微镜、透射电子显微镜观察及荧光免疫组织化学染色的方法进行培养细胞的鉴定.结果 培养的细胞块3 d后可见部分细胞突起长出,7 d后整个组织块周围放射状长出较多细胞.倒置相差显微镜下,培养细胞呈一端细胞体丰富膨大,另一端有一长突起,细胞核椭圆形,常有2个或2个以上核仁;透射电子显微镜下,细胞胞体大,细胞浆丰富,内含丰富的8～10 nm的微丝.荧光免疫组织化学法显示细胞呈神经胶质纤维酸性蛋白和胞内视黄醛结合蛋白阳性,阳性率达95%以上.结论 运用组织块培养法可培养出兔视网膜Müller细胞.

Abstract：

Objective To develop a method for the primary culture of retinal Müller cells of adult rabbit in vitro. Methods Retina was isolated from adult rabbit, cut into 1 mm × 1 mm pieces, and placed into Dulbecco modified Eagle medium/F12 containing 20 % fetal bovine serum to culture. Cultured cells were identified by inverted phase contrast microscope, transmissim electron microscope and immunohistochemistry staining method. Results Visible cell processes grew out from the retinal tissues after three days culture, and more cells grew radically around the retina after seven days culture. The cultured cells were often inflated at one side and had one long process at another side, and the nuclei were elliptical and there were two or more than two nucleoli under inverted phase contrast microscope. The cytoplasm was rich and contained abundant microfilaments in eight to ten nanometers under transmission electron microscope. Immunohistochemistry assay showed that 95% of the cells were positive for glial can be cultured by the explant culture method.     

视网膜Müller细胞的研究现状

Müiler细胞是脊椎动物视网膜最重要的胶质细胞,了解其在健康视网膜的生理及功能和在病变视网膜的病理变化,可更好地理解在病变视网膜Müller细胞的胶质反应,探索有效的治疗措施.成年哺乳动物视网膜Müller细胞具有神经干细胞特性,在特定的条件下可能被激活,井受:Notch等一些信号通路的调控.视网膜Müller细胞在维持视网膜正常结构和功能中起重要作用,在病变视网膜中Müller细胞主要表现胶质增多反应,对神经元的功能既有保护又有损害,而Müller细胞的干细胞特性为视网膜神经元再生和对视网膜病变的治疗引出了新方向.     

视网膜Müller细胞与谷氨酸代谢

视网膜Müller细胞作为重要的星形胶质细胞,在维持视网膜正常功能方面具有重要的作用,在病理状态下也可以通过蛋白表达、反应性胶质增生、谷氨酸(glutamate,Glu)转运体的表达、谷氨酰胺合成酶的改变和分泌神经营养因子等途径对Glu代谢进行干预,从而起到保护视网膜神经元免受Glu神经性毒性损伤的作用.     

Müller细胞干细胞特性的研究进展

视网膜退行性病变缺少有效的防治方法.研究显示,Müller细胞可表达视网膜神经元细胞标记物如钙视网膜蛋白、视黄醛结合蛋白等.人Müller细胞不但可表达神经干细胞相关转录因子如SOX2、PAX6、CHX10、NOTCH1,还表达视网膜神经元标记物如双极细胞标记物蛋白激酶C,光感受器神经元标记物(盘膜边缘蛋白),神经节细胞标记物HuD与Brn3,大部分神经元标记物神经丝蛋白、βⅢ微管蛋白,神经节细胞、无长突细胞和水平细胞阳性标记物(钙视网膜蛋白).因此表明,视网膜Müller细胞可分化成不同视网膜神经元细胞,具有干细胞特性,利用Müller细胞进行细胞移植可能是治疗视网膜退行性病变具有潜力的新策略.     

Müller细胞与视网膜神经再生研究进展

视网膜退行性疾病是以视网膜神经元凋亡为主要病理过程的一类致盲性眼病,视网膜神经元受损后再生困难,Müller细胞是参与视网膜发育、受损及再生过程的重要胶质细胞。近年研究证明,Müller细胞是视网膜神经元的内源性替代来源,为视网膜神经再生的优秀靶标。本文根据视网膜神经再生过程、Müller细胞与视网膜神经再生相关因素进行综述,为神经再生研究提供新方向。     

Müller glial cells in retinal disease

Virtually all pathogenic stimuli activate Müller cells. Reactive Müller cells exert protective and toxic effects on photoreceptors and neurons. They contribute to oxidative stress and glutamate toxicity due to malfunctions of glutamate uptake and glutathione synthesis. Downregulation of potassium conductance disrupts transcellular potassium and water transport, resulting in neuronal hyperexcitability and edema. Protective effects of reactive Müller cells include upregulation of adenosine 5'-triphosphate (ATP)-degrading ectoenzymes, which enhances the extracellular availability of the neuroprotectant adenosine, abrogation of the osmotic release of ATP, which might protect retinal ganglion cells from apoptosis, and the release of antioxidants and neurotrophic factors. The dedifferentiation of reactive Müller cells to progenitor-like cells might have an impact on future therapeutic approaches. A better understanding of the gliotic mechanisms will be helpful in developing efficient therapeutic strategies aiming at increased protective and regenerative properties and decreased toxicity of reactive Müller cells.