兔视网膜Mller细胞的原代培养

目的探索体外培养兔视网膜Mller细胞的有效方法。方法采用酶消化法从乳兔视网膜获取Mller细胞,通过振荡和反复洗涤使之纯化。采用免疫组织化学技术和透射电镜对传代Mller细胞进行鉴定。结果培养24h后即有部分细胞贴壁生长,72h后贴壁细胞进一步增多。通过振荡吹打可使附着于Mller细胞上的神经元脱落。20～25d后细胞接近融合,呈三角形或不规则形。传代后细胞经1周达到融合。培养细胞GFAP阳性率在95%以上。电镜观察显示:细胞内含有线粒体、粗面内质网、核糖体及8～10nm的中间丝。结论利用酶消化法可成功分离兔视网膜Mller细胞,通过振荡和吹打洗涤,可使之纯化。     

罗格列酮对糖尿病视网膜Müller细胞的保护作用以及对Müller细胞胶质纤维酸性蛋白（GFAP）及炎症因子表达的影响

目的　通过建立糖尿病大鼠模型,研究罗格列酮对糖尿病视网膜Müller细胞的保护作用以及对Müller细胞胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）及炎症因子表达的影响。方法　取健康清洁级雄性SD大鼠36只,分为对照组、糖尿病组、罗格列酮治疗组,每组12只大鼠。糖尿病组及罗格列酮治疗组大鼠建立糖尿病模型;罗格列酮治疗组每天给予罗格列酮3 mg·kg^-1灌胃,糖尿病组和对照组每天给予等体积的生理盐水灌胃。12周后,对大鼠体质量、血糖进行评估。免疫荧光检测大鼠视网膜Müller细胞活化标志物GFAP的表达。利用Western blot对细胞间黏附分子-1（intercellular cell adhesion molecule-1,ICAM-1）、肿瘤坏死因子α（tumor necrosis factor-α,TNF-α)、GFAP的表达变化进行半定量分析。结果　与对照组相比,糖尿病组及罗格列酮治疗组大鼠体质量明显降低,血糖明显升高（均为P＜0.01）。与糖尿病组相比,罗格列酮治疗组大鼠体质量无明显变化（P>0.05）,但血糖降低（P＜0.01）。对照组、糖尿病组、罗格列酮治疗组GFAP免疫荧光表达量分别为82.68±2.65、225.88±5.59、158.89±6.22;与对照组相比,糖尿病组表达量明显增高（P＜0.01）;与糖尿病组相比,罗格列酮治疗组表达量明显降低（P＜0.01）。对照组、糖尿病组、罗格列酮治疗组ICAM-1 蛋白相对表达量分别为（5.91±0.13）%、（57.43±0.92）%、（55.56±1.23）%;与对照组相比,糖尿病组表达量明显增加（P＜0.01）;与糖尿病组相比,罗格列酮治疗组表达量明显减少（P＜0.01）。对照组、糖尿病组、罗格列酮治疗组TNF-α蛋白相对表达量分别为（11.25±1.43）%、（67.36±1.79）%、（44.79±2.12）%;与对照组相比,糖尿病组表达明显增加（P＜0.01）;与糖尿病组相比,罗格列酮治疗组表达量明显减少（P＜0.01）。对照组、糖尿病组、罗格列酮治疗组GFAP蛋白相对表达量分别为（17.79±0.74）%、（64.82±1.23）%、（46.15±2.05）%;与对照组相比,糖尿病组表达明显增加（P＜0.01）;与糖尿病组相比,罗格列酮治疗组表达量明显减少（P＜0.01）。结论　罗格列酮能降低糖尿病视网膜炎症反应,保护Müller细胞,对DR具有潜在的治疗作用。     

静态压力对视网膜米勒细胞表达胶质纤维酸性蛋白和热休克蛋白-70的影响

目的观察静态压力对视网膜Mueller胶质细胞（RMGC）数量和表达胶质纤维酸性蛋白（GFAP）和热休克蛋白（HSP）70的影响。设计实验性研究。研究对象大鼠RMGC。方法体外培养并鉴定大鼠RMGC，对该细胞施以不同程度的静态压力，分为A（1．33kPa）、B（2．67kPa）、C（5．33kPa）、D（10．67kPa）四组，设立未加压者为正常对照组（NC）。用倒置相差显微镜观察细胞形态结构变化，常规细胞记数方法计算细胞数量，台盼蓝染色计算各组活细胞比例。采用蛋白电泳的方法比较各组细胞中GFAP和HSP70的表达情况。主要指标细胞形态，细胞数量，细胞活性。结果随着压力增加细胞数量降低，C和D组细胞数量低于NC组、A和B组（P〈0．01）。压力导致各组细胞拒染率降低（P〈0．01），C和D组细胞拒染率低于NC组、A和B组（P〈0．01）。C和D组细胞形态结构有明显损伤，随着压力的进一步增加，细胞的损伤程度也进一步加重。NC组RMGC表达GFAP和HSPTO蛋白的水平低于压力组，C和D组GFAP表达略高于A和B组，但各压力组HSPTO表达无明显差异。结论过高的静态压力会直接损伤RMGC，RMGC表达GFAP和HSPTO水平升高，可能是高眼压条件下视网膜损伤反应的标志之一。（眼科，2007,16：44-47）     

CDK抑制剂对糖尿病大鼠视网膜Müller细胞胶质增殖及新生血管形成的抑制作用

目的　探讨CDK抑制剂对糖尿病大鼠视网膜Müller细胞胶质增殖及新生血管形成的影响。方法　雄性SD大鼠30只，随机分成对照组、糖尿病组、治疗组(CDK抑制剂SCH727965)，每组各10只。后两组大鼠采用单次腹腔注射55 mg·kg^-1链脲佐菌素(streptozotocin,STZ)的方法诱导糖尿病模型。模型诱导成功后，治疗组玻璃体内注射SCH727965 8 μL(3 nmol·L^-1)。12周后，免疫荧光检测三组大鼠视网膜胶质纤维酸性蛋白质(glial fibrillary acidic protein,GFAP)、血管内皮生长因子(vascular endothelial growth factor,VEGF)表达，免疫组织化学检测视网膜色素上皮衍生因子(pigment epithelium-derived factor,PEDF)表达，Western blot检测GFAP、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)、PEDF蛋白相对表达量。结果　与对照组GFAP (100.00±0.00)%、VEGF(100.00±0.00)%、PEDF(38.26±0.52)%、PCNA(9.34±0.47)%表达相比，糖尿病组GFAP(168.24±2.72)%、VEGF(156.79±1.75)%、PCNA(16.11±0.34)%表达均明显增加，PEDF(23.72±0.71)%表达明显降低(均为P<0.01)；而与糖尿病组相比，治疗组GFAP(124.37±3.01)%、VEGF(118.36±1.98)%、PCNA(12.05±0.67)%表达均明显降低，PEDF(8.22±0.36)%表达明显增加(均为P<0.05)。结论　SCH727965可下调大鼠糖尿病状态下视网膜GFAP、VEGF、PCNA表达，上调PEDF表达，进而抑制Müller细胞增殖及新生血管形成。     

Müller细胞在视网膜损伤中对视神经节细胞影响的研究进展

Müller细胞是视网膜中主要神经胶质细胞,贯穿视网膜全层。尽管近年来针对Müller细胞功能的研究较多,但是Müller细胞和视网膜神经节细胞(retinal ganglion cells,RGCs)的相互作用关系仍不完全清楚。目前已知生理状态下Müller细胞的许多功能和RGCs密切相关,例如Müller细胞已经证实为神经元祖细胞的来源,调节视网膜细胞间质K⁺水平和谷氨酸代谢,维持视网膜内能量代谢和营养支持等。在视网膜损伤时,Müller细胞相关功能对RGCs的影响也十分重要。因此,本文就此研究进展进行综述,以期为视网膜中视神经的保护治疗提供新的思路。     

糖尿病大鼠视网膜神经细胞损伤机制的研究

目的 观察糖尿病大鼠视网膜Müller细胞谷氨酸转运体（GLAST）、谷氨酰胺合成酶（GS）及胶质纤维酸性蛋白（GFAP）表达的变化、视网膜神经细胞凋亡的检测以及神经营养因子NT-3的表达,探讨糖尿病（DM）对视网膜神经细胞损伤的机制。设计 实验研究。研究对象 Sprague-Dawley（SD）大鼠82只。 方法 大鼠随机分为正常对照组12只,糖尿病模型组70只。链脲佐菌素诱导实验性DM大鼠模型。RT-PCR法检测视网膜GFAP mRNA表达水平;TUNEL法检测视网膜神经节细胞（RGC）及内核层细胞的凋亡并计数凋亡细胞数量;免疫组织化学技术LSAB法检测GFAP、GLAST、GS、NT-3在视网膜的表达,观察DM大鼠视网膜RGC及内核层细胞功能的改变,用图像分析仪测量免疫组化的显色强度。主要指标 GFAP、GLAST、GS和NT-3的表达量,视网膜内核层和RGC细胞凋亡数。结果 （1）与正常组（1.00±0.02）相比,模型组GFAP阳性表达量（5.22±1.34）明显增加（P=0.000）, GLAST、GS、NT-3阳性表达明显降低。（2）大鼠视网膜凋亡阳性细胞仅见于RGC层和内核层,模型组视网膜内核层细胞及RGC凋亡数量（36.00±6.02,11.48±2.08）比正常组（16.33±2.34,5.34±0.52）显著增加（P均=0.000）。（3）DM大鼠视网膜GFAP mRNA表达（7.00±0.37）比正常组（0.29±0.08）明显增加（P=0.000）。（4）GFAP阳性表达与内核层细胞及RGC凋亡数呈正相关（r=0.88、0.85,P=0.021、0.028 ）;GLAST阳性表达与内核层细胞及RGC凋亡数呈负相关（r=-0.91、-0.89, P=0.014、0.020）,GS阳性表达与内核层细胞及RGC凋亡数呈负相关（r=-0.93、-0.90, P=0.007、0.009）;NT-3阳性表达与内核层细胞及RGC凋亡数呈负相关（r=-0.74、-0.71, P=0.036、0.041）。结论  糖尿病大鼠视网膜神经细胞凋亡增加与Müller细胞的过度反应性增生及神经营养因子的缺失有关,高浓度谷氨酸的兴奋性毒性作用以及神经营养因子NT-3的缺失是其视网膜神经细胞损伤的重要机制。     

PKC对豚鼠近视眼视网膜Mller细胞近视因子基因的调控作用

目的研究蛋白激酶C（PKC）对豚鼠近视眼视网膜Mtiller细胞中酪氨酸羟化酶（TH）、诱导型NO合成酶（iNOS）、神经型NO合成酶（nNOS）、碱性成纤维细胞生长因子（bFGF）、转化生长因子B（TGFl3）基因表达的调控作用。方法眼罩遮盖法建立豚鼠近视眼模型,酶消化法原代培养其视网膜Müller细胞,GFAP免疫组织化学染色进行细胞鉴定。根据干预因素不同,把Müler细胞分为正常对照组、近视组、近视＋GF109203X组、近视＋PMA组和近视＋DMSO组。RT—PCR检测TH、iNOS、nNOS、bFGF和TGFβmRNA的表达情况。结果与正常对照组比较,近视眼视网膜Mtiller细胞iNOS、nNOS、bFGF和TGFβmRNA表达上调,THmRNA表达下调（P〈0．05）。PKC激活剂（PMA）激活PKC后,近视眼视网膜Müller细胞表达nNOS、iNOS、TH和bFGFmRNA上调（P〈0．05）;GF109203X抑制PKC活性后,这些因子的mRNA表达下调（P〈n05）。结论豚鼠近视眼视网膜Müller细胞nNOS、iNOS、bFGF和TH基因的表达受PKC调控,Müller细胞可能为近视信号因子的一个重要来源。     

兔视网膜Müller细胞的原代培养

目的 探索体外培养兔视网膜Müller细胞的有效方法.方法 采用酶消化法从乳兔视网膜获取Müller细胞,通过振荡和反复洗涤使之纯化.采用免疫组织化学技术和透射电镜对传代Müller细胞进行鉴定.结果 培养24 h后即有部分细胞贴壁生长,72 h后贴壁细胞进一步增多.通过振荡吹打可使附着于Müller细胞上的神经元脱落.20～25 d后细胞接近融合,呈三角形或不规则形.传代后细胞经1周达到融合.培养细胞GFAP阳性率在95%以上.电镜观察显示细胞内含有线粒体、粗面内质网、核糖体及8～10 nm的中间丝.结论 利用酶消化法可成功分离兔视网膜Müller细胞,通过振荡和吹打洗涤,可使之纯化.     

高眼压鼠视网膜胶质纤维酸性蛋白免疫组织化学观察

通过观察高眼压后Ｍｕｌｌｅｒ细胞胶质纤维酸性蛋白的表达情况,探讨Ｍｕｌｌｅｒ细胞在高眼压性视网膜损伤听作用及意义。方法前房加压灌注法制作 大鼠急性高压模型,免疫组织化学方法显示视网膜上ＧＦＡＰ的表达,并采用计算机图像分析系统驾定量。     

人视网膜星形胶质细胞发育及起源的研究

背景 视网膜星形胶质细胞是视网膜主要的神经胶质细胞,其起源及演变过程一直是国内外研究的热点和难点. 目的 探讨人胚胎眼视网膜星形胶质细胞的起源及发育.方法 收集33例自愿终止妊娠的流产人胚胎眼标本,其中8 ～12孕周者20例,15～ 17孕周者2例,19～ 23孕周者4例,25～ 28孕周者4例,30 ～32孕周者3例.对眼球壁切片进行常规组织病理学检查以观察不同胚龄人视网膜发育的形态学变化,分别采用免疫组织化学法及免疫荧光法动态观察不同胚龄人视网膜星形胶质细胞起源位点及发育过程中胶质纤维酸性蛋白( GFAP)表达的变化.结果 人胚6～7周视杯处于视网膜分层发育阶段,9周时视杯内层原无细胞层出现分化不成熟的圆短梭形细胞;胚龄15周时视网膜主要层次可见,分化的细胞增加,但未发现GFAP阳性细胞;胚龄19周视网膜可见梭形细胞从返折部原始神经上皮迁出,并可见这些细胞中GFAP呈阳性表达;胚龄25～ 26周后极部视网膜可见GFAP表达阳性的梭形细胞,这些细胞围绕视网膜血管分布,与血管壁联系密切,邻近锯齿缘处的视网膜内层可见表达GFAP的星形或梭形细胞与睫状体非色素上皮相连,但锯齿缘稍后与赤道区之间并未见GFAP阳性细胞;胚龄28周,视网膜星形胶质细胞呈典型的星状,其突起伸达视网膜内网状层. 结论 人视网膜星形胶质细胞至少存在3个起源位点,即血管前体细胞/周皮细胞、视盘旁原始神经上皮及邻近锯齿缘的睫状体无色素上皮.     

视网膜光损伤的药物防治

视网膜光化学损伤可致感光细胞凋亡和视网膜变性,严重导致视力丧失。近10余年来,人们对药物防治光损伤进行了大量研究,包括神经营养因子、抗氧化剂、自由基清除剂、钙通道阻滞剂及皮质激素等。本对各种药物的保护作用作一综述。     

Antibody-mediated retinal pericyte injury: implications for diabetic retinopathy

Purpose. To test the hypothesis that autoantibodies against retinal pericytes could develop in diabetic retinopathy, and that these autoantibodies could induce retinal pericyte dysfunction/death via complement. Methods. Human primary retinal pericytes cultured in media containing normal (5 mM) or high (30 mM) glucose concentrations were incubated with normal human sera in the presence of a retinal pericyte-reactive antibody, then their viability was assessed by a BCECF-based cytotoxicity assay, and their function was assessed by a T-cell proliferation assay. The pericytes were also analyzed by RT-PCR and flow cytometry to detect CD38, an established diabetes-associated cell surface autoantigen. The potential of the anti-CD38 antibodies in inducing pericyte cellular injury was evaluated using the same cytotoxicity assays. In addition, autoantibody-mediated cytotoxicity in mouse retinal pericytes sensitized by sera from mice with developing diabetic retinopathy or control normal mice were also studied. Results. Retinal pericyte-reactive antibodies induced cellular damage by activating complement in the serum. The antibody-injured pericytes had reduced efficacy in inhibiting T cells. Hyperglycemic culture conditions rendered pericytes more susceptible to antibody-mediated attack. CD38 was expressed in retinal pericytes, and upregulated by TNF-α and IFN-γ, and anti-CD38 antibodies induced pericyte cytotoxicity. Retinal pericytes sensitized with sera from chronic diabetic mice suffered significantly augmented cytotoxicity compared with those sensitized with sera from the control mice. Conclusions. The autoantibody-initiated complement activation could be a mechanism underlying the loss of function, and eventually, death of retinal pericytes in diabetic patients, suggesting that inhibiting complement activation could be a novel therapeutic approach.     

Acute retinal necrosis: a new pathophysiological hypothesis.

A 76-year-old woman with unilateral acute retinal necrosis had an elevated titer of cytomegalovirus (CMV) antibodies with both in the aqueous humor and serum. The serological pattern indicated recent CMV infection, and the Goldmann-Witmer coefficient comparing aqueous and serum titers was above 4 indicating intraocular production of specific antibodies. The clinical characteristics and results as well as a new possible etiopathogenic hypothesis are presented.     

Plasma miR-26a-5p is a biomarker for retinal neurodegeneration of early diabetic retinopathy

PurposeRetinal neurodegeneration is an early pathological change in diabetic retinopathy (DR). Early-stage retinal neurodegeneration is usually asymptomatic. This study aims to identify circulating microRNAs (miRNAs) as sensitive biomarkers for early retinal neurodegeneration.MethodsWe profiled the plasma miRNA expression in three mild nonproliferative diabetic retinopathy (NPDR) cases and three matched non-DR patients using RNA sequencing. The differential miRNAs were validated with qRT-PCR. The retinal nerve fibre layer (RNFL) thickness of the eyes was measured using spectral-domain Optical coherence tomography (SD-OCT). The association between differential miRNAs and RNFL thickness was analysed using the Pearson correlation analysis. Bioinformatics tools were used to predict potential targets of miRNA associated with RNFL thickness and investigate the functions of the potential target genes.ResultsRNA sequencing identified 69 differential miRNAs and eight of them were reported to be associated with DR. The qRT-PCR for these eight miRNAs validated the down-regulation of circulating miR-26a-5p and miR-126-5p in a larger validating cohort. A positive correlation between plasma miR-26a-5p level and the RNFL thickness of the superior quadrant of both eyes was identified in another cohort, including 33 mild NPDR cases, 33 matched non-DR patients and 20 healthy controls. Furthermore, 367 candidate targets of miR-26a-5p were predicted. The functional studies revealed that these target genes are profoundly involved in various cellular functions and signalling pathways.ConclusionsCirculating miR-26a-5p is a potential biomarker for early-stage retinal neurodegeneration and it may be involved in the development of DR via profoundly influencing the functions of retinal cells.Subject terms: Retina, Prognostic markers     

Diffuse retinal injury from a non-penetrating TASER dart

To describe a non-penetrating TASER gun injury resulting in a small exudative retinal detachment but significant visual acuity and retinal function loss as demonstrated by electroretinography (ERG). A 39-year-old man presented to the emergency department with a TASER barb embedded in his right lower lid. A complete clinical ophthalmologic examination and surgical extrication were performed, as well as radiologic imaging and Ganzfeld electroretinography. No scleral penetration was observed on surgical exploration. Retinal examination showed a peripheral exudative detachment. Subsequent follow-up revealed progressive resolution of the detachment and improvement in visual acuity. The ERG showed a 63–70% decrease in rod a- and b-waves, while isolated cone responses were reduced by only 10%, with a minimal increase in implicit time. This case shows that periocular TASER injuries, even if apparently superficial, may result in significant ocular damage. ERG may be useful in the diagnosis of visual loss attributed to disturbance in photoreceptor function, in the absence of anatomically evident damage.