兔胚胎全层视网膜移植至大鼠视网膜下的观察

视网膜色素变性(RP)是一组能导致进行性感光细胞变性和视觉障碍的遗传病症候群，目前尚无有效治疗方法。近年来研究表明视网膜移植是最接近临床应用治疗RP的方法。当RP进展到晚期，感光细胞和视网膜色素上皮(RPE)细胞都出现变性死亡，单独移植这两种成分都没有作用，此时病变视网膜的修复需要全层视网膜的移植。我们将青紫蓝兔胚胎全层视网膜移植到正常Wistar大鼠和视网膜变性RCS大鼠的视网膜下腔，观察移植物在宿主视网膜下腔的发育状况，从而探讨异种胚胎全层视网膜移植方法的可行性。     

视网膜感光细胞的移植

近十年多来,视网膜移植的研究已取得了很大进步,它可分为视网膜植片移植和视网膜细胞移植。细胞移植的前景十分广阔,它包括基因转移作为治疗方法的潜力巨大。目前,视网膜细胞移植中研究较多是色素上皮细胞(RPE)和感光细胞的移植。视网膜感光细胞移植开始于80年代中期,对感光细胞变性的疾病,移植纯的感光细胞具有针对性,且能减少玫瑰花结构的形成。我们拟就近年来视网膜感光细胞的移植的有关问题作一综述。一、移植细胞的分离和纯化分离出足够数量和适当纯度的细胞以替代受体功能不全的细胞是细胞移植最关键的第一步。为使移植细胞能更好发…     

骨髓间充质干细胞玻璃体腔移植对大鼠青光眼模型视神经的保护作用

目的：探讨骨髓间充质干细胞玻璃体腔移植对大鼠青光眼模型的神经保护作用。

方法：提取大鼠原代骨髓间充质干细胞并进行鉴定; Lewis大鼠分别随机分为3组：对照组、青光眼模型组和骨髓间充质干细胞组,并制作青光眼大鼠模型：左眼为实验眼(青光眼),右眼为对照眼,并进行鉴定; 然后进行骨髓间充质干细胞玻璃体腔移植; HE染色观察视网膜组织形态; 免疫荧光法检测视网膜神经节细胞数量; TUNEL染色观察视网膜神经节细胞凋亡情况; Western blot检测视网膜组织中IGF1和BDNF蛋白表达情况。

结果：大鼠实验眼的眼内压均明显高于对照眼(P<0.01),表明青光眼大鼠模型均建造成功; 青光眼模型组大鼠视网膜神经纤维排列不整齐,视网膜神经节细胞数量和视网膜厚度显著低于对照组(P<0.01),视网膜神经节细胞凋亡数量显著高于对照组(P<0.001); 骨髓间充质干细胞组大鼠视网膜神经纤维细胞排列较整齐,视网膜神经节细胞数量和视网膜厚度明显高于青光眼模型组(P<0.05),视网膜神经节细胞凋亡数量明显低于青光眼模型组(P<0.05); 青光眼模型组大鼠视网膜中IGF1和BDNF蛋白表达量明显低于对照组(P<0.01),骨髓间充质干细胞组大鼠的视网膜中IGF1和BDNF蛋白表达量高于青光眼模型组(P<0.05)。

结论：骨髓间充质干细胞玻璃体腔移植能改善大鼠青光眼,可以保护视网膜神经节细胞。     

视网膜干细胞移植任重而道远

进行性视网膜感光细胞的死亡是许多视网膜变性疾病的共同特征。现有的治疗方法不能恢复已经丧失的视功能。视网膜干细胞移植研究的不断深入在为视网膜变性患者带来希望的同时也面临一些严峻挑战：如何获得理想的视网膜干细胞？如何诱导视网膜干细胞分化成视杆及视锥细胞？如何诱导移植的细胞与受体细胞形成功能性突触连接？感光细胞丧失的早期,内部的视网膜神经通路是完整的,新的感光细胞只需与双极细胞形成突触连接就能恢复完整的视网膜神经通路。而感光细胞替换通常比其它神经元更直接更容易。因为感光细胞是感觉神经元,只在一个方向上与双极细胞一水平细胞形成连接。另外,视网膜特殊的层状结构决定了视网膜外层的感光细胞层是视网膜干细胞移植最理想的位置。视网膜干细胞研究的进展、视网膜变性疾病的特征及视网膜的特殊结构让我们有理由相信,干细胞移植的成功将首先来自视网膜感光细胞移植。     

基于Nrf2/Keap1/ARE通路研究槲皮素对小鼠年龄相关性黄斑变性的保护作用

目的：探讨槲皮素通过Nrf2/Keap1/ARE通路对小鼠年龄相关性黄斑变性的保护作用及机制研究。

方法：以昆明小鼠为研究对象,分为：对照组、模型组、槲皮素组; 眼底检查各组小鼠眼底是否出现黄白色似玻璃疣物质; OCT检查各组小鼠视网膜厚度; HE染色观察各组小鼠视网膜形态的改变; FFA观察各组小鼠眼底血管完整性; ELISA检测小鼠血清中SOD、GSH-Px、CAT活性和ROS、MDA含量变化; Western blot检测各组小鼠视网膜中Nrf2/Keap1/ARE相关蛋白的表达情况。

结果：槲皮素能使小鼠眼底的黄白色似玻璃膜疣物质减少且视网膜厚度增加(P<0.05),视网膜血管渗漏点明显减少; 与模型组比较,槲皮素组小鼠的a波振幅、b波振幅较模型组均明显上升(P<0.01); 槲皮素能使小鼠视网膜结构比较清晰,部分外核层发生坏死脱落,且使小鼠血清中ROS、MDA含量降低(均P<0.05),SOD、GSH-Px、CAT活性提高(均P<0.05); 与模型组比较,槲皮素组小鼠视网膜细胞质中Nrf2蛋白表达上调(P<0.05),细胞核中Nrf2蛋白表达下调(P<0.05),小鼠视网膜中Keap1、HO-1、NQO-1、GCL蛋白表达下调(均P<0.05)。

结论：槲皮素可能通过Nrf2/Keap1/ARE通路,改善视网膜光损伤后的氧化应激状态,保护视网膜功能,对年龄相关性黄斑变性具有保护作用。     

视网膜类器官治疗视网膜退行性疾病的研究进展

视网膜退行性疾病是导致视力受损与失明的重要原因。目前,对于感光细胞大量丧失的疾病晚期阶段尚无有效的治疗方案。近年来,大量研究提供了感光细胞的移植替代治疗的新思路,而视网膜3D培养技术产生的视网膜类器官能够在体外产生移植所需的感光细胞及组织,为视网膜退行性疾病的移植替代治疗奠定了基础。本文通过综述视网膜3D培养技术以及感光细胞移植的发展,着重阐述视网膜类器官在视网膜退行性疾病移植替代治疗中的现有运用策略以及局限性,以期为视网膜3D培养技术在感光细胞替代治疗中的优化提供理论参考。     

嘌呤受体P2X7对视网膜毛细血管周细胞凋亡的影响

目的：探讨嘌呤受体P2X₇在体外培养大鼠视网膜毛细血管周细胞上的功能意义。

方法：利用显微镜下观察结合TUNEL计数法分别测定P2X₇激动剂BzATP和拮抗剂OxATP对体外培养的正常视网膜毛细血管周细胞以及糖尿病大鼠视网膜毛细血管周细胞存活率的影响。

结果：P2X₇受体激动后可介导视网膜毛细血管周细胞死亡,糖尿病大鼠视网膜毛细血管周细胞较正常视网膜毛细血管周细胞,在同等激动剂浓度下或在同样的时间点,能引起更多的细胞凋亡。而拮抗剂OxATP可以明显减轻BzATP对视网膜毛细血管周细胞的毒性作用,提高其存活率。

结论：P2X₇受体活性对视网膜毛细血管周细胞凋亡有一定调控作用。     

ω-3多不饱和脂肪酸抑制小鼠视网膜新生血管的实验研究

目的：探讨膳食途径摄入ω-3多不饱和脂肪酸(polyunsaturated fatty acids,PUFAs)抑制小鼠视网膜新生血管的作用及其机制。

方法：选取60只7日龄C57BL /6J小鼠随机分为3组：A组在正常环境中给予普通膳食饲养; B、C组是将小鼠与哺乳母鼠共同置于氧浓度为75%±2%的氧箱内饲养5d后转移至正常氧环境中饲养5d建立氧诱导视网膜病变模型,其中C组按体质量给予ω-3PUFAs 7.5mg/(kg·d)饲养,B组给予普通膳食饲养。分别于出生后17d时处死小鼠,铺片法计算视网膜新生血管相对面积,HE染色检测突破内界膜的血管内皮细胞核数目,GC-MS检测视网膜组织中ω-3PUFAs/ω-6PUFAs相对含量和比例,实时荧光定量聚合酶链反应(Real-Time PCR)分析视网膜组织中过氧化物酶增殖活化受体-γ(preoxisome proliferator-activated receptor γ,PPAR-γ)、血管内皮生长因子-A(VEGF-A)和血管内皮生长因子受体2(VEGFR-2)的mRNA表达。

结果： 出生后17d三组小鼠间新生血管面积及突破视网膜内界膜的血管内皮细胞核数比较差异有统计学意义(F_{新生血管面积}=20.45,P<0.05; F_{内皮细胞核数}=48.66,P<0.05),新生血管面积A组与B组之间比较,差异有统计学意义(t=8.64,P<0. 05),C组与B组之间比较,差异有统计学意义(t=8.91,P<0.05)。HE染色法观察内皮细胞核数,A组与B组比较差异有统计学意义(t=38.51,P<0.05); C组与B组比较差异有统计学意义(t=19.86, P<0.05)。三组小鼠视网膜ω-3PUFAs和ω-6PUFAs相对含量比较,差异有统计学意义(F=129.86、112.44,均P<0.05),C组含量分别与A、B组比较,差异均有统计学意义(t=23.15、25.42; t=16.43、11.95,均P<0.05); 三组小鼠视网膜ω-3PUFAs/ω-6PUFAs比例、视网膜PPAR-γ mRNA表达、视网膜VEGF-A mRNA表达、视网膜VEGFR-2 mRNA表达比较,差异有统计学意义(F_比例=10.30,F_PPAR-γ=138.24,F_VEGF-A=69.12,F_VEGFR-2 =52.45,均P<0.05),C组ω-3PUFAs/ω-6PUFAs比例与B组比较提高,差异均有统计学意义(P<0.05); C组PPAR-γ mRNA表达水平明显高于B组,C组VEGF-A mRNA表达水平及VEGFR-2 mRNA表达水平低于B组,差异均有统计学意义(P<0.05)。

结论：通过膳食途径摄入一定量的ω-3PUFAs,可能通过上调ω-3PUFAs/ω-6PUFAs比例,激活PPAR-γ,进而减少VEGF-A和VEGFR-2表达,抑制视网膜新生血管形成。     

光感受器移植在视网膜退行性疾病中的应用研究进展

视网膜退行性疾病是影响人类视力的主要疾病，使人感光细胞受损，损害人的视力。而且哺乳动物的视网膜没有再生能力，一旦患病会严重影响人们的正常生活。目前尚未有明确的预防和减缓该类疾病的方法，但移植光感受器以补充视网膜中受损的感光细胞可以治疗视网膜疾病。本文将讨论光感受器移植方法在视网膜退行性疾病中恢复视力的现状和移植技术。     

丹蒌片通过Keap1-Nrf2/HO-1信号通路缓解视网膜缺血-再灌注损伤

目的：探讨丹蒌片对小鼠视网膜缺血-再灌注损伤(RIRI)的保护作用及其机制。

方法：将40只ApoE^-/-小鼠给予高脂饲料喂养6 wk,通过前房灌注加压法建立RIRI模型,分为对照组(给予生理盐水灌胃8 wk)、RIRI模型组(给予生理盐水灌胃8 wk)及丹蒌片低、中、高剂量组\〖分别给予丹蒌片溶液1、2、4 g/(kg·d)灌胃8 wk\〗。采用苏木精-伊红(HE)染色观察各组小鼠视网膜组织形态学变化情况,TUNEL染色检测各组小鼠视网膜细胞凋亡情况,Western-blot法检测各组小鼠视网膜组织中Kelch样环氧氯丙烷相关蛋白-1(Keap1)、转录因子核因子E2相关因子2(Nrf2)、血红素加氧酶-1(HO-1)、超氧化物歧化酶(Sod2)蛋白表达情况。

结果：与对照组比较,RIRI模型组小鼠视网膜萎缩,厚度变薄,细胞凋亡增加,视网膜组织中Sod2蛋白表达下调,Keap1蛋白表达上调(均P<0.01); 与RIRI模型组比较,丹蒌片中、高剂量组小鼠视网膜厚度增加(均P<0.01),丹蒌片低、中、高剂量组小鼠视网膜细胞凋亡降低(均P<0.05),丹蒌片低剂量组小鼠视网膜组织中Keap1和HO-1蛋白表达水平无明显差异(P>0.05),丹蒌片中、高剂量组小鼠视网膜组织中Sod2、Nrf2、HO-1蛋白表达上调,Keap1蛋白表达下调(均P<0.05)。

结论：丹蒌片能缓解RIRI小鼠模型视网膜萎缩变薄,减少视网膜细胞凋亡,其作用是通过调控Keap1-Nrf2/HO-1信号通路降低RIRI氧化应激反应来实现。     

Photoreceptor allografts in a feline model of retinal degeneration

· Background: Photoreceptor transplants provide a potential means to restore function in a degenerate retina and/or rescue degenerating host photoreceptors by trophic influences. We have examined photoreceptor allografts in the Abyssinian cat model of hereditary photoreceptor degeneration to determine the viability and influence of such transplants on the host retina. · Methods: Small pieces of 3- to 5-day-old normal kitten retina containing undifferentiated photoreceptors were injected into the subretinal space of adult Abyssinian cats at an early stage of retinal degeneration using standard vitreo-retinal surgical techniques. The retinas were examined by ophthalmoscopy and fundus photography, then by light and electron microscopy at different times after surgery. · Results: Such allografts survive for at least 6 months after surgery. The photoreceptors develop outer segments, invariably in rosettes. The transplants gradually integrate with the host retina but detach the host photoreceptor layer from the retinal pigment epithelium (RPE), which tends to reduce the number of host photoreceptors over the transplant. There is no slowing of the photoreceptor degeneration in neighboring non-detached retina. Inflammation or rejection was not detected. · Conclusion: Undifferentiated, neonatal photoreceptor allografts survive and develop outer segments in the subretinal space of the Abyssinian mutant feline retina. The allografts gradually integrate with the host neural retina without inducing rejection. In the vicinity of the transplant there is increased loss of host photoreceptors, considered to be due to their detachment from the RPE layer. There is no evidence of any rescue of host photoreceptors elsewhere in this mutant retina. Received: 10 November 1997 Revised version received: 19 March 1998 Accepted: 23 March 1998     

视网膜视细胞的成片移植

目的 探索用准分子激光切削技术制备视网膜单层细胞植片,经内入路视网膜下腔的单层视细胞成片移植。方法 用准分子激光对大鼠视网膜进行切削,制取单层视细胞植片,此后,按内入路手术方法进行了兔视网膜下腔的异种移植。结果 切削后所得视细胞植片由单层视细胞组成,结构完整,包括外丛状层、外核层和外节层;视细胞植片经明胶包埋后被准确植入宿主视网膜下腔中,移植术后第1,2天宿主观视网膜未能复位,呈脱离状态,移植物没能与视网膜色素上皮层相贴;移植后10天,宿主视网膜复位,视细胞移植片平铺于宿主视网膜下腔中,植片视细胞外节也宿主视网膜色素上皮层相贴;移植后10天,宿主视网膜复位,视细胞移植片平铺于宿主视网膜下腔中,植片视细胞外节与宿主视网膜色素上皮层相贴,未见明显免疫排异现象。结论 准分子激光制备单层视细胞植片方法简单、可行;初步观察到内入路单层视细胞成片移植后,视细胞植片能够在宿主视网膜下腔中以正常生理位置存活;视网膜下腔为理想的视网膜移植的受位。     

经巩膜外路至视网膜下腔移植视网膜细胞的实验研究

探讨视网膜光感受器细胞的移植方法及临床意义。方法将16只昆明鼠随机分为A组和B组,每组均8只鼠。于手术显微镜下,用特殊显微注射器穿过巩膜、脉络膜,在A组昆明鼠的视网膜下腔注入视网膜混合细胞,在B组昆明鼠的视网膜下腔注入纯光感受器细胞。于移植术后30、90及180 d摘除实验眼,于光镜下观察移植细胞在视网膜下腔生长的情况。结果大多数标本(13／15)HE染色显示视网膜细胞准确移植在受体眼的视网膜下腔,未见炎性细胞浸润和受体视网膜破坏;且移植到受体视网膜下腔的细胞在术后180 d仍存活。仅少数(2／15)标本可见受体视网膜结构破坏。移植的视网膜混合细胞均形成“玫瑰花”样结构,而移植的纯视网膜光感受器细胞则在视网膜下腔形成整齐的细胞层。结论经巩膜外路至视网膜下腔的显微注射法是较为理想的视网膜下腔注射给药和视网膜细胞移植方式。纯视网膜光感受器细胞移植后的生长状况和功能接近正常生理状态的视网膜组织结构,为临床治疗视网膜变性疾病提供了新途径。     

Immunobiology and privilege of neuronal retina and pigment epithelium transplants

Despite the existence of ocular immune privilege, immune rejection may be a barrier to successful retinal transplantation. We have examined in mice the extent to which the subretinal space (SRS) is an immune privileged site, and whether retinal pigment epithelium and neuronal retinal tissue have properties of immune privileged tissues. We report that (1) The SRS is an immune privileged site; (2) Neonatal RPE is an immune privileged tissue; (3) Neuronal retina is a partially immune privileged tissue; and (4) Microglia within neonatal neural retina grafts promote photoreceptor differentiation, become activated, and induce sensitization of the recipient and serve as targets of immune rejection.     

视网膜变性小鼠视网膜组织中FasL蛋白表达的动态变化

背景 视网膜移植是治疗视网膜变性性疾病的新方法,但如何避免或减少视网膜移植后的免疫排斥反应是亟待解决的问题之一.目前的实验研究中常将正常C57 BL/6小鼠视网膜作为供体,视网膜变性(rd)小鼠作为受体.研究表明视网膜中Fas配体(FasL)蛋白通过FasL/Fas途径诱导Fas+炎症细胞凋亡,推测可能与视网膜移植后的免疫排斥反应密切相关. 目的 探讨FasL蛋白在不同鼠龄C57BL/6小鼠和rd小鼠视网膜中的表达特点,揭示小鼠视网膜的免疫特性,为视网膜移植免疫排斥反应的研究提供参考依据.方法 分别将出生后(PN)-0周(出生日)、PN-1周、PN-2周、PN-3周、PN-4周的正常C57BL/6小鼠和rd小鼠处死制备眼球冰冻切片,采用免疫荧光技术摄片,并经激光扫描共焦显微镜采集图片,用图像分析软件对各鼠龄不同品系小鼠间视网膜中FasL蛋白表达的荧光强度(FI)变化进行半定量分析. 结果 PN-1周C57BL/6小鼠视网膜发育尚不完善,FasL蛋白在视网膜各层均呈阳性表达.PN-2、3、4周C57BL/6小鼠已发育成10层的视网膜结构,FasL蛋白在视网膜色素上皮(RPE)、内节段(IS)、外界膜(OLM)、外丛状层(OPL)、内核层(INL)、内丛状层(IPL)及节细胞层(GCL)呈阳性表达.PN-1周rd小鼠视网膜结构与同龄C57BL/6小鼠接近,FasL蛋白在视网膜各层均呈阳性表达.PN-2周至PN-4周rd小鼠视网膜中外核层(ONL)细胞随着鼠龄增大逐渐减少,FasL蛋白在RPE、OPL、INL、IPL及GCL呈阳性表达;PN-2、3、4周rd小鼠RPE中FasL蛋白表达FI值分别为184.199±16.747、186.797±7.904和184.319±18.795,均明显高于同龄C57BL/6小鼠的160.402±22.851、160.995±22.799和105.787±17.676,差异均有统计学意义(t=-3.360,P=0.002;t’=-4.277,P=O.000;t=-12.175,P=0.000);各周龄rd小鼠与C57BL/6小鼠间视网膜IPL中FasL蛋白表达的FI值差异均无统计学意义(均P＞O.05).结论 rd小鼠随着鼠龄增加视网膜ONL细胞逐渐减少,其RPE内免疫赦免相关抗原FasL蛋白的表达强度明显高于同龄C57BL/6小鼠.     

Full-thickness retinal transplants: a review

Embryonic full-thickness rabbit neuroretinal sheets were transplanted to the subretinal space of adult hosts. This was accomplished by using a new transplantation technique involving vitrectomy and retinotomy. The grafts were followed from 10 to 306 days after surgery and were then examined by different histological techniques. In the light microscope, the transplants were seen to develop the normal retinal lamination and fusion with the host retina, especially after long survival times. Ultrastructurally, normal photoreceptor outer segments, well integrated with the host retinal pigment epithelium, were found. Growth cones were present in the zone of fusion between graft and host retina. Immunohistochemical labeling revealed many of the normal retinal components not previously found in retinal transplants, and graft-host connections between neurons in the rod pathway were seen. The morphology of vibratome-sectioned neuroretinal sheets as well as adult full-thickness grafts was also examined. These transplantation types showed less of the normal morphology compared with embryonic full-thickness grafts. The immunogenicity of embryonic full-thickness and fragmented grafts was compared using major histocompatibility complex immunolabeling. Fragmented grafts elicited a response from the host immune system similar to a chronic transplant rejection. This reaction was absent in the full-thickness grafts which is in accordance with their good long-term survival.     

Multipotent retinal progenitors express developmental markers, differentiate into retinal neurons, and preserve light-mediated behavior

PURPOSE: To use progenitor cells isolated from the neural retina for transplantation studies in mice with retinal degeneration. METHODS: Retinal progenitor cells from postnatal day 1 green fluorescent protein-transgenic mice were isolated and characterized. These cells can be expanded greatly in culture and express markers characteristic of neural progenitor cells and/or retinal development. RESULTS: After they were grafted to the degenerating retina of mature mice, a subset of the retinal progenitor cells developed into mature neurons, including presumptive photoreceptors expressing recoverin, rhodopsin, or cone opsin. In rho-/- hosts, there was rescue of cells in the outer nuclear layer (ONL), along with widespread integration of donor cells into the inner retina, and recipient mice showed improved light-mediated behavior compared with control animals. CONCLUSIONS: These findings have implications for the treatment of retinal degeneration, in which neuronal replacement and photoreceptor rescue are major therapeutic goals.     

去小胶质细胞化对糖尿病小鼠视网膜光感受器细胞的影响

目的　观察去小胶质细胞化对早期糖尿病小鼠视网膜光感受器细胞的影响。方法　选取6~8周龄的SPF级雄性C57BL/6J小鼠作为实验动物,未经处理的5只作为空白对照组（A组）,10只采用链脲佐菌素（STZ）腹腔注射法成功诱导出糖尿病后的小鼠随机等分为B、C两组。A、B组继续喂养标准实验饲料4周,C组在喂养1周标准实验饲料后添加含290 mg?kg^-1 PLX3397（集落刺激因子1受体拮抗剂）的AIN-76A（标准饮食配制的啮齿类实验动物纯化饲料）3周以去除小胶质细胞。4周后于同一时间点处死各组动物,眼球标本均于处死后即刻获取并固定。制备视网膜石蜡切片,HE染色后光学显微镜下观察视网膜结构;小胶质细胞特异性抗体P2ry12免疫荧光化学法检测小胶质细胞在视网膜上的分布,并测算平均吸光度(D)值以间接代表小胶质细胞的数量;TUNEL法测定光感受器细胞的凋亡情况;将上述观察指标在三组间进行比较。结果　光镜观察视网膜结构显示,与A组相比,B组神经纤维层变水肿,内丛状层、内核层及外核层排列变疏松;C组也出现上述改变,但程度较轻。小胶质细胞的免疫荧光化学检测结果显示:A组可在视网膜内层检测到少量的小胶质细胞;B组的小胶质细胞则分布于视网膜全层,提示其由内层向全层发生迁移;C组在各层均未检测到小胶质细胞。B组视网膜P2ry12的D值均较A组和C组高（t=3.478、8.166,均为P<0.05）,A组也明显高于C组（t=30.409,P<0.001）。光感受器细胞每高倍视野凋亡数A、B、C三组分别为 (0.67±0.87)个、(9.22±1.56)个、(2.22±0.97)个,B组与A组及C组相比差异均有统计学意义（t=14.360、11.408,均为P<0.001）;A组凋亡细胞数较C组少,差异均有统计学意义（t=-3.585,P=0.02）。结论　在糖尿病早期小胶质细胞参与了糖尿病视网膜光感受器细胞的损害过程,通过早期对小胶质细胞进行耗竭化处理可缓解视网膜的水肿和外核层细胞的凋亡。     

Retinal pigment epithelial cell transplantation after subfoveal membranectomy in age-related macular degeneration: clinicopathologic correlation

PURPOSE: To report the histopathology after retinal pigment epithelial cell transplantation and subfoveal membranectomy in age-related macular degeneration. METHODS: An 85-year-old white woman with bilateral choroidal neovascularization underwent subfoveal membranectomy combined with transplantation of a sheet of human adult retinal pigment epithelium (retinal pigment epithelium) under the foveal center in the right eye. The patient was immunosuppressed postoperatively with prednisone, cyclosporine, and azathioprine. The patient died from congestive heart failure 114 days after surgery. RESULTS: A patch of hyperpigmentation was visible at the transplant site under the foveola after surgery. Mound-like clusters of individual round, large densely pigmented cells were present in the subretinal space and outer retina in this area. There was loss of the photoreceptor outer segments and native retinal pigment epithelium in the center of the transplant bed, with disruption of the outer nuclear layer predominantly over regions of multilayered pigmented cells. Cystic spaces were present in the inner and outer retina. A residual intra-Bruchs membrane component of the original choroidal neovascular complex was present under the transplant site. CONCLUSIONS: The transplant site contained clusters of round, pigmented cells that did not form a uniform monolayer in most areas. The morphology at the transplant site is consistent with the lack of visual improvement seen after surgery in this patient.