Seaton A D, Sheedlo H J, Turner J E
Department of Ophthalmology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina.
Invest Ophthalmol Vis Sci. 1994 Jan;35(1):162-9.
Healthy retinal pigment epithelial (RPE) cell transplants in retinas of postnatal day 27 Royal College of Surgeons (RCS) rat are capable of preventing photoreceptor cell degeneration, inhibiting the degeneration of the retinal vascular bed and the subsequent neovascularization of the RPE that occurs in retinas injected with saline. In the present study, the authors have tested the hypothesis that RPE transplants might also prevent vascularization of the RPE layer in RCS retinas when photoreceptor cells either had just degenerated or, at 3 months, disappeared.
Retinas of 3- and 6 month-old RCS rats were injected with either healthy neonatal RPE cells or vehicle and were examined at 6 and 8 months, respectively. These retinas were studied using horseradish peroxidase visualization of the vasculature in retinal wholemount preparations and by light microscopy.
The number of neovascular profiles in wholemount preparations of RCS retinas that had received healthy RPE transplants at 3 months and were analyzed at 6 months were significantly decreased when compared to sham-injected retinas of age-matched RCS rats, 2.09 +/- 0.94 and 15.28 +/- 1.34 profiles per mm2, respectively (P < 0.001). In addition, when comparing retinas transplanted or sham injected at 6 months and examined at 8 months, significantly fewer neovascular profiles were found in the transplant group, 9.32 +/- 1.02 and 15.42 +/- 0.84 profiles per mm2, respectively (P < 0.002).
These data provide still further evidence for the role of healthy RPE in maintaining the homeostasis of the normal retinal vasculature in the retina of the RCS rat. The relationships between the RPE and the retinal vasculature are important when considering that alterations in the vascularization of the retina play a major role in some of the most sight-debilitating diseases, such as the wet form of age-related macular degeneration and proliferative diabetic retinopathy.
将健康的视网膜色素上皮（RPE）细胞移植到出生后第27天的皇家外科学院（RCS）大鼠视网膜中，能够预防光感受器细胞变性，抑制视网膜血管床变性以及随后在注射生理盐水的视网膜中发生的RPE新生血管形成。在本研究中，作者检验了这样一个假设：当光感受器细胞刚刚变性或在3个月时消失时，RPE移植也可能预防RCS视网膜中RPE层的血管形成。
给3个月和6个月大的RCS大鼠视网膜注射健康的新生RPE细胞或赋形剂，分别在6个月和8个月时进行检查。使用辣根过氧化物酶对视网膜整装标本中的脉管系统进行可视化处理，并通过光学显微镜对这些视网膜进行研究。
与年龄匹配的RCS大鼠假注射视网膜相比，3个月时接受健康RPE移植并在6个月时进行分析的RCS视网膜整装标本中的新生血管轮廓数量显著减少，分别为每平方毫米2.09±0.94和15.28±1.34个轮廓（P<0.001）。此外，比较6个月时移植或假注射并在8个月时检查的视网膜，移植组中发现的新生血管轮廓明显较少，分别为每平方毫米9.32±1.02和15.42±0.84个轮廓（P<0.002）。
这些数据进一步证明了健康RPE在维持RCS大鼠视网膜中正常视网膜脉管系统稳态方面的作用。考虑到视网膜血管形成的改变在一些最严重影响视力的疾病中起主要作用，如湿性年龄相关性黄斑变性和增殖性糖尿病视网膜病变，RPE与视网膜脉管系统之间的关系很重要。
