Repigmentation of human retinal pigment epithelial cells in vitro.
Cultured human retinal pigment epithelial (RPE) cells readily ingested both melanin and lipofuscin isolated from human RPE cells. Up to 7 days post-challenge ingested granules demonstrated no evidence of lysis or aggregation within secondary lysosomes. When cultures containing ingested melanin and lipofuscin were subcultured the cells gradually depigmented due to a redistribution of pigment granules amongst daughter cells. Quantitative analysis demonstrated that the accumulation of both types of granule was linear over a 24 hr challenge period. This study reports a technique of 'artificially' repigmenting cultured human RPE cells and thus offers the potential for in vitro investigations of the role of these inclusions in various dynamic aspects of cellular metabolism.
D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D006801:Humans; D008062:Lipofuscin / Q000378:metabolism; D008543:Melanins / Q000378:metabolism; D008854:Microscopy, Electron; D008875:Middle Aged; D010587:Phagocytosis; D010857:Pigment Epithelium of Eye / Q000378:metabolism* / Q000648:ultrastructure; D010858:Pigmentation; D012168:Retinal Pigments / Q000378:metabolism*
D008062:Lipofuscin; D008543:Melanins; D012168:Retinal Pigments