灯盏细辛对大鼠视神经压榨伤后视网膜神经节细胞的保护作用

目的　探讨中草药灯盏细辛对大鼠标定性视神经压榨伤所致的视网膜神经节细胞(RGC)损伤的防护和修复作用。方法　 4 2只健康SD大鼠随机均分为A组和B组。两组均用特制微型视神经夹直接夹持视神经 ,制作成单眼视神经部分压榨伤模型后 ,A组不予任何治疗 ,B组予以灯盏细辛治疗 ,直至处死动物。以上两组按致伤日至处死日动物的存活时间又分为 :A1组和B1组 (损伤后 4d) ,A2 组和B2 组 (损伤后 14d) ,A3 组和B3 组 (损伤后 2 1d) ,每组各 7只大鼠。于处死前 3d双上丘直接注射 3%快蓝标记双眼RGC。处死日行眼球摘除术后 ,将双眼全视网膜组织铺片置于荧光显微镜下 ,在距视乳头 1mm处的颞上、颞下、鼻下及鼻上 4处作荧光摄影 ,并输入计算机经图像分析仪计数RGC。计算RGC标识率 ,即 (损伤眼RGC数 /未损伤眼RGC数 )× 10 0 % ,并进行统计学分析。结果　A组大鼠中 ,A1、A2 及A3 组的RGC标识率分别为 (77 79± 7 11) %、(6 3 76± 3 79) %、(5 4 6 6±4 75 ) % ;B组大鼠中 ,B1、B2 及B3 组的RGC标识率分别为 (80 13± 12 0 3) %、(78 17± 9 19) %及(83 5 9± 12 6 1) %。A2 和A3 组分别与B2 和B3 组比较 ,差异均有非常显著意义 (t=14 10 8,36 2 0 3;P<0 0 1)。结论　大鼠标定性视神经压榨伤后用灯盏细辛治疗 ,     

视网膜神经节细胞钾离子通道的表达与功能

视网膜神经节细胞（retinal ganglion cells,RGCs）不可逆性凋亡是视神经损害的主要原因.在许多视神经相关疾病中如青光眼、年龄相关性黄斑变性、糖尿病视网膜病变、葡萄膜炎和玻璃体视网膜病变等,RGCs凋亡是视觉障碍的一个主要原因.RGCs的电性能主要取决于离子通道的存在.各种离子通道中,钾离子通道起到了非常关键的作用.本文就钾离子通道在RGCs上的表达及其功能进行综述.     

银杏叶提取物对急性缺血再灌注后视网膜神经节细胞的保护作用

目的探讨银杏叶提取物（EGb761）对大鼠急性高眼压诱导缺血再灌注模型中视网膜神经节细胞（RGCs）的保护作用。方法60只SD大鼠随机分为5组,右眼为损伤眼,行前房穿刺灌注形成110mmHg的眼压维持60min,左眼未损伤,作为空白对照。损伤后2h及此后每日1次灌胃给药,各组分别给予生理盐水5mg／kg、1％灯盏细辛5mg／kg、0．25％EGb761 5mg／kg、1％EGb7615mg／kg和4％EGb761 5mg／kg。动物损伤后第23天用荧光金行双上丘逆行标记,第28天取眼球标本做视网膜铺片并拍摄照片,计数RGCs并计算其的存活率。结果生理盐水组、1％灯盏细辛组、0．25％EGb761、1％EGb761和4％EGb761组RGCs存活率分别为66．58％、75．62％、74．92％、76．57％、79．87％。生理盐水组与各EGb761组之间差异均有统计学意义（q=0．00,q=0．19,q=0．10,P〈0．01）,不同质量浓度EGb761组之间差异均无统计学意义（q=0．22,q=0．13,q=0．45,P〉0．05）;1％灯盏细辛组与生理盐水对照组比较差异有统计学意义（q=0．16,P=0．02）,与0．25％EGb761组、1％EGb761组、4％EGb761组比较差异均无统计学意义（q=0．20,q=0．01,q=0．50,P〉0．05）。结论在急性高眼压诱导缺血再灌注模型中,银杏叶提取物能有效地保护RGCs。     

灯盏细辛对兔高眼压视网膜神经节细胞活性的作用

目的观察灯盏细辛对慢性高眼压兔视网膜神经节细胞活性的保护作用。方法对20只健康新西兰白兔右眼前房内注射40g·L-1甲基纤维素,制成慢性高眼压模型,左眼眼压均正常,随机分成灯盏细辛治疗组(n=10,高眼压+灯盏细辛治疗亚组和正常眼压+灯盏细辛治疗亚组)和未治疗组(n=10,单纯高眼压亚组和单纯正常眼压亚组)。治疗组于高眼压模型制作后第7d开始行灯盏细辛悬浊液灌胃,60d后制作眼球标本。常规石蜡切片,AgNOR染色观察RGCs细胞核内的银染颗粒。采用计算机图像分析系统对RGCs细胞核内的银染颗粒进行定量分析。结果高眼压2亚组较正常眼压2亚组的RGCs细胞核内银染颗粒明显减少,其差异有显著性意义(P<0.05);其中高眼压+灯盏细辛治疗亚组较单纯高眼压亚组银染颗粒多(P<0.05)。结论40g·L-1甲基纤维素前房注射建立慢性高眼压模型可导致RGCs细胞核内银染颗粒减少,灯盏细辛对高眼压后RGCs活性有一定的保护作用。     

青光眼视网膜神经节细胞凋亡的实验研究

目的 研究兔的实验性青光眼视网膜神经节细胞的死亡是否有凋亡参与。方法 前房注入固定的红细胞悬液使免眼压升高,分别在术后７,１４,２１,２８天处死动物,取视网膜组织,ＴＵＮＥＬ标记染色,电镜观察。结果 电镜下可见视网膜神经节细胞死亡特征为典型的凋亡早期特征－核浓染。免疫组ＴＵＮＥＬ法实验组发现神经节细胞凋亡,而正常对照组没有发现。结论 实验性青光眼的视网膜神经节细胞死亡有凋亡参与。这为通过调探凋亡而治疗青光眼的视网膜视神经损伤提供可能。     

青光眼视网膜节细胞损伤的研究进展

青光眼是一种主要的致盲眼病,随着对青光眼研究的深入,逐渐认为高眼压和/或缺血造成视网膜节细胞(retinal ganglion cells,RGCs)以凋亡的方式不断丢失,而神经营养因子、谷氨酸、NO、自由基及Ca2+的浓度变化参与了RGCs的凋亡过程。我们通过本文综述了参与青光眼RGCs损伤的几种因素。     

视网膜神经节细胞无血清上清培养液诱导大鼠视网膜干细胞的分化

目的　探讨视网膜神经节细胞无血清上清培养液对视网膜干细胞分化的影响。方法　分离大鼠视网膜干细胞和视网膜神经节细胞;采用免疫荧光法鉴定体外培养的大鼠视网膜干细胞与视网膜神经节细胞,视网膜干细胞以Nestin抗体进行鉴定,视网膜神经节细胞以Thy-1抗体进行鉴定;以视网膜神经节细胞无血清上清培养液培养视网膜干细胞,以不加入条件培养液培养的视网膜干细胞为对照组,收集分化细胞,采用qPCR法检测Nestin、Pax6、Thy-1及Brn-3的基因表达。结果　培养的视网膜干细胞Nestin抗体染色阳性,视网膜神经节细胞Thy-1抗体染色阳性。培养视网膜干细胞72 h后,与对照组相比,无血清上清培养液组细胞Nestin和PAX6基因相对表达量降低,差异均有统计学意义（均为P<0.000 1）;Thy-1和Brn-3基因相对表达量升高,差异均有统计学意义（均为P<0.05）。结论　视网膜神经节细胞无血清上清培养液能够诱导视网膜干细胞分化为视网膜神经节样细胞。     

Neurotoxic effects of trypan blue on rat retinal ganglion cells

To facilitate the peeling of internal limiting membrane or epiretinal membrane in vitreoretinal surgery, trypan blue (TB) and indocyanine green (ICG) have been used. However, the cytotoxicity of these dyes have been concerned. The aim of this study was to investigate the neurotoxic effects of TB on rat retinal ganglion cells (RGCs) and compare the effect of TB with ICG. Rat RGCs were purified by a two-step immunopanning procedure. In short-time exposure experiments, purified RGCs cultured for 3 days were exposed to 600 mgL(-1) TB, 1500 mgL(-1) TB and 1500 mgL(-1) ICG for 10 sec to 30 min. The number of viable RGCs was counted after 12 hr in culture. In long-time exposure experiments, purified RGCs were cultured for 3 days in TB solutions ranging from 2 to 800 mgL(-1) or in ICG solutions at concentrations from 2 to 250 mgL(-1). Then the number of viable cells was counted. Exposure to 600 mgL(-1) TB, 1500 mgL(-1) TB and 1500 mgL(-1) ICG for short time from 10 sec to 30 min caused a time-dependent damage to RGCs. There was no significant difference in cytotoxicity to RGCs between TB and ICG in short-time exposure. In long-time exposure, TB as well as ICG showed neurotoxic effect on RGCs in a dose-dependent manner. Fifty percentage inhibitory concentration (IC50) of TB to RGCs was calculated as 115 mgL(-1), while that of ICG was 33 mgL(-1). In conclusion, TB induced neurotoxic effect on RGCs in a dose- and time-dependent manner. During the short-time exposure in surgery, there is likely no difference in neurotoxic effect on RGCs between TB and ICG. However, once the dyes are left in the eyes after surgery, TB may show less toxicity on RGCs than ICG.     

巨噬细胞培养液对离体培养的大鼠视网膜神经节细胞的作用研究

目的研究巨噬细胞培养液对离体培养的视网膜神经节细胞(retinal ganglioncells,RGCs)存活和生长的作用,探讨损伤晶状体促进RGCs存活和轴突再生的作用物质,为视神经损伤和再生的基础研究提供理论依据。方法制备大鼠巨噬细胞培养液,分别用巨噬细胞培养液及DMEM对RGCs进行离体培养,观察RGCs在体外存活的时间,测量培养1d、3d和5d有突起的RGCs数目及最长突起长度,进行组间比较。结果(1)对照组离体培养的细胞于培养5～6d崩解死亡,而巨噬细胞培养液组细胞能存活6～8d;(2)培养1d、3d和5d,巨噬细胞培养液组有突起的RGCs数目分别为(59.74±2.04)个.mm-2、(96.78±4.11)个.mm-2和(99.26±3.04)个.mm-2,均明显多于同期对照组,差异非常显著(P<0.01);(3)培养1d和3d,巨噬细胞培养液组RGCs最长突起长度分别为(39.70±0.71)μm和(76.19±1.56)μm,较对照组延长,差异非常显著(P<0.01)。培养5d,RGCs最长突起长度与对照组比较差异显著(P<0.05)。结论巨噬细胞培养液可促进离体培养的RGCs存活和生长。     

Latanoprost protects rat retinal ganglion cells from apoptosis in vitro and in vivo

We investigated whether latanoprost has a direct anti-apoptotic effect in retinal ganglion cell (RGC) line and RGCs in the rat. RGC-5 cells were induced to undergo apoptosis by serum deprivation and exogenous glutamate. The level of cell death with or without latanoprost acid was monitored by an XTT assay and by immunocytochemistry with activated caspase-3. Changes in the level of intracellular calcium ([Ca²⁺]i) were measured with fluo-4 fluorescence. The XTT assay revealed that latanoprost acid increased RGC-5 cell viability. Latanoprost acid significantly reduced caspase-3 positive cells and suppressed [Ca²⁺]i evoked by glutamate. U0126, a mitogen-activated protein/extracellular signal-regulated kinase 1 and 2 inhibitor, partially blocked the rescue effect of latnanoprost acid (p = 0.013). In vivo, rat RGCs were degenerated by optic nerve crush. After topical instillation of latanoprost for 7 days, RGCs labeled with fluorogold were significantly. Retinal flatmounts were subjected to terminal dUTP nick end labeling (TUNEL) staining to detect apoptotic cells. TUNEL-positive cells were significantly decreased in eyes with topically instilled latanoprost (p = 0.015). These data suggest that latanoprost has an neuroprotective ability in RGCs.     

Influence of hypoxia on retinal progenitor and ganglion cells in human induced pluripotent stem cell-derived retinal organoids

AIM: To observe the effect of low oxygen concentration on the neural retina in human induced pluripotent stem cell (hiPSC)-derived retinal organoids (ROs). METHODS: The hiPSC and a three-dimensional culture method were used for the experiments. Generated embryoid bodies (EBs) were randomly and equally divided into hypoxic and normoxic groups. Photographs of the EBs were taken on days 38, 45, and 52, and the corresponding volume of EBs was calculated. Simultaneously, samples were collected at these three timepoints, followed by fixation, sectioning, and immunofluorescence. RESULTS: The proportion of Ki67-positive proliferating cells increased steadily on day 38; this proliferation-promoting effect tended to increase tissue density rather than tissue volume. On days 45 and 52, the two groups had relatively similar ratios of Ki67-positive cells. Further immunofluorescence analysis showed that the ratio of SOX2-positive cells significantly increased within the neural retina on day 52 (P<0.05). In contrast, the percentage of PAX6- and CHX10-positive cells significantly decreased following hypoxia treatment at all three timepoints (P<0.01), except for CHX10 at day 45 (P>0.05). Moreover, the proportion of PAX6-/TUJ1+ cells within the neural retinas increased considerably (P<0.01, <0.05, <0.05 respectively). CONCLUSION: Low oxygen promotes stemness and proliferation of neural retinas, suggesting that hypoxic conditions can enlarge the retinal progenitor cell pool in hiPSC-derived ROs.     

视网膜神经节细胞标记方法的研究进展

目前对视网膜神经节细胞(RGCs)进行标记研究的基本方法有多种。逆行标记法是标记研究RGCs的常用方法,但存在许多不足之处。近年来,人们发现RGCs内或胞体上存在某些特异的抗原,因此尝试使用免疫标记的方法标记检测RGCs。本文综述近年来对RGCs进行标记的研究进展。     

Differentiation of retinal ganglion cells from induced pluripotent stem cells: a review

Glaucoma is a common optic neuropathy that is characterized by the progressive degeneration of axons and the loss of retinal ganglion cells (RGCs). Glaucoma is one of the leading causes of irreversible blindness worldwide. Current glaucoma treatments only slow the progression of RGCs loss. Induced pluripotent stem cells (iPSCs) are capable of differentiating into all three germ layer cell lineages. iPSCs can be patient-specific, making iPSC-derived RGCs a promising candidate for cell replacement. In this review, we focus on discussing the detailed approaches used to differentiate iPSCs into RGCs.     

B族维生素对体外培养大鼠视网膜神经细胞及节细胞的神经营养作用

目的评价维生素B1、B6、B12及其衍生物甲钴胺对视网膜神经细胞及神经节细胞(RGCs)的生存和轴突再生伸长的影响。方法采用新生大鼠视网膜神经细胞体外原代培养技术，与不同浓度的B族维生素共同培养，MTT比色法检测细胞活力，进行HE染色和抗Thy1免疫细胞化学染色，测量视网膜神经细胞和RGCs轴突长度，比较各种维生素对细胞轴突伸长的影响。结果维生素B1、B6、B12和甲钴胺的最有效作用浓度分别为100、100、1．0、1．0μmol／L；高密度培养该营养作用更明显。用该浓度作用于细胞，维生素B6、B12和甲钴胺可促进视网膜神经细胞和RGCs轴突伸长。结论B族维生素在体外短期内能够显著提高视网膜神经细胞和RGCs的活力，促进上述细胞轴突再生伸长。     

Muller细胞对青光眼视网膜神经节细胞影响的研究进展

视网膜神经节细胞（RGCs）的过度凋亡是青光眼病理改变的基础。Mller细胞作为视网膜的主要神经胶质细胞,对于维持神经元的完整性、代谢、内环境稳态以及信号转导等均具有重要的作用。随着对Mller细胞研究的逐渐深入,发现Mller细胞不仅参与了青光眼性RGCs的凋亡机制,而且还参与了RGCs的代偿性保护机制。那么Mller细胞是如何对RGCs起作用,它又是通过什么机制参与青光眼引起的RGCs凋亡以及代偿性保护作用呢？就这些问题的最新研究进展进行综述。     

小干扰RNA保护大鼠视网膜神经节细胞的实验研究

 目的 通过大鼠视神经夹伤模型,研究小干扰RNA（siRNA）对视网膜神经节细胞（RGC）的保护作用。设计 实验研究。 研究对象 SPF级SD大鼠54只。方法 54只SD大鼠随机分为A、B、C三组,每组18只。均选取右眼为实验眼,左眼为正常对照。在球后2 mm处用40 g压力微型视神经夹夹持视神经60 s,做视神经夹伤模型。建立模型后当天,A、B、C三组分别给予玻璃体注射10 μg、20 μg siRNA和生理盐水。视神经夹伤后10天,每组取6只大鼠用荧光金做逆行标记,14天时取标记后的大鼠双眼眼球标本做视网膜铺片并拍摄照片,RGC计数。计算RGC存活率（右眼RGC数/左眼RGC数×100%）。每组其余12只大鼠进一步用蛋白印迹法检测视网膜组织中caspase-3蛋白的表达水平。主要指标 RGC存活率,caspase-3蛋白的表达水平。结果 A、B、C组RGC存活率分别为53.63%±7.35%、57.86%±6.00%、45.00%±4.37%（F=7.11,P=0.029）,其中A组与C组（P=0.025）,B组和C组（P=0.002）之间均有显著性差异;A 组和B组之间无显著性差异（P=0.24）。A、B、C三组视网膜组织中Caspase-3蛋白与内参灰度比值分别为0.20±0.02、0.19±0.02、0.24±0.03（F=9.73,P=0.02）。其中A组与C组（P=0.005）,B组和C组（P=0.001）之间均有显著性差异;A 组和B组之间无显著性差异（P=0.418）。结论 小干扰RNA能有效保护大鼠视神经夹伤模型的RGC,提高RGC的存活率。     

视网膜神经节细胞保护的药物治疗

视网膜神经节细胞(RGCs)是青光眼、眼外伤等神经退行性病变的主要损伤细胞,它的死亡常导致视功能的不可逆性损害。     

Preliminary quantitative proteomic characterization of glaucomatous rat retinal ganglion cells

Quantitative proteomic analysis was pursued of retinal ganglion cells (RGCs) from rats with unilateral experimental glaucoma. RGCs were isolated from 22 animals by immunopanning after 8 weeks of sustained elevated intraocular pressure. Proteins were quantified by LC MS/MS iTRAQ technology. Of the 268 proteins quantified, ∼8% appeared elevated and ∼13% decreased in glaucomatous RGCs. Voltage-dependent anion channel protein 2, aldose reductase, and ubiquitin were among the significantly elevated proteins while prothymosin was among the significantly decreased. The results demonstrate the feasibility of identifying global proteomic differences in protein expression between purified glaucomatous and control in vivo RGCs.     

牛磺酸保护视网膜神经节细胞的研究进展

牛磺酸是动物组织内常见的氨基酸,近年来很多研究提示其对视网膜神经节细胞具有重要保护功能,其作用机制可分为以下6种：(1)降低NMDA(N-甲基-D-天冬氨酸)诱导的兴奋毒性;(2)调节Müller细胞的功能;(3)保护线粒体功能;(4)促进视神经再生;(5)促进适应性调节;(6)改善眼底微循环。在各类眼病中,青光眼则是以视网膜神经节细胞损害为主的疾病。目前体内及体外试验证明牛磺酸可从多方面对抗视网膜神经节细胞损伤,为包括青光眼在内的多种眼科疾病的视神经保护治疗开辟了潜在途径。     

氧化应激诱导视网膜神经节细胞凋亡的研究进展

视网膜神经节细胞(retinal ganglion cells,RGCs)凋亡是青光眼、糖尿病视网膜病变、视神经炎等多种疾病过程中的一个重要环节。在这些疾病过程中,氧化应激参与诱导RGCs的凋亡。近年的实验研究发现抗氧化应激药物对RGCs有良好的保护作用。我们将近年来氧化应激诱导RGCs凋亡以及相关抗氧化应激药物的研究进展做一综述。