Wassell J, Ellis S, Burke J, Boulton M
Department of Ophthalmology, Manchester Royal Eye Hospital, United Kingdom.
Invest Ophthalmol Vis Sci. 1998 Jul;39(8):1487-92.
To compare the fluorescence properties of autofluorescent granules generated by retinal pigment epithelial (RPE) cells in vitro with those of the lipofuscin of RPE in vivo.
Cultured human RPE cells were maintained in basal medium for as long as 1 year, fed rod outer segments (ROS) daily for as long as 56 days, fed ROS in the presence and absence of leupeptin, or fed liposomes consisting of the major phospholipids in ROS. At different time points, cells were examined for overall fluorescence, and their fluorescence spectra were determined. In addition, chloroform-methanol extracts were examined by thin-layer chromatography and compared with those generated from RPE lipofuscin.
Autofluorescent granules accumulated in cultured RPE cells, regardless of the presence of an exogenous substrate or the nature of the substrate. The rate of accumulation of autofluorescent granules was greatest in cells fed ROS. The autofluorescent material generated in cultured RPE cells had some spectral similarities with RPE lipofuscin but differed in solubility and chromatographic mobility of their constituent fluorophores. CONCLUSIONS. The autofluorescent granules generated by cultured RPE, even with different specific substrates, differ from lipofuscin granules in vivo, suggesting that additional properties of RPE cells or of the materials they phagocytose are required to produce autofluorescent materials with the characteristics of lipofuscin.
比较视网膜色素上皮（RPE）细胞在体外产生的自发荧光颗粒与体内RPE脂褐素的荧光特性。
将培养的人RPE细胞在基础培养基中培养长达1年，每天喂食视杆外段（ROS）长达56天，在有和没有亮抑酶肽的情况下喂食ROS，或喂食由ROS中的主要磷脂组成的脂质体。在不同时间点，检查细胞的总体荧光，并测定其荧光光谱。此外，通过薄层色谱法检查氯仿 - 甲醇提取物，并与从RPE脂褐素产生的提取物进行比较。
无论是否存在外源性底物或底物的性质如何，自发荧光颗粒都在培养的RPE细胞中积累。在喂食ROS的细胞中，自发荧光颗粒的积累速率最大。培养的RPE细胞中产生的自发荧光物质与RPE脂褐素在光谱上有一些相似之处，但其组成荧光团的溶解度和色谱迁移率不同。结论。培养的RPE产生的自发荧光颗粒，即使使用不同的特定底物，也与体内的脂褐素颗粒不同，这表明需要RPE细胞或它们吞噬的物质的其他特性才能产生具有脂褐素特征的自发荧光物质。
