A Study of Lipofuscin on Cultured Human Retinal Pigment Epithelium

ABSTRACT

One consistent finding in the aging human RPE is the intracellular accumulation of lipofuscin Lipofuscin was applied to the cell culture technique to clarify the relationship between age related macular degeneration and lipofuscin accumulation in the human RPE. The results obtained in this study are as follows 1. The initial suspensions of dissociated RPE cells consisted of densely pigmented and hexagonal cells. Rapid cell proliferation and confluency of a culture occured from 2 weeks after seeding. No pigment granule was observed in subcultured cells of 3rd passage. 2. When RPE cultures were subcultured the cells gradually de pigmented due to a redistribution of pigment granules. Quantitative analysis demonstrated that intensity of fluorescence for a certain number of cells reduced proportionally as the cell division proceeded. 3. Cultured human retinal pigment epithelial cells readily ingested lipofuscin isolated from human RPE cells. The amount of lipofuscin phagocytized by cultured RPE cells were greater than that phagocytized by aged cells. Accumulation and/or saturation of lipofuscin in the RPE cells at least in cell culture did not necessarily affect RPE cell survival.