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In vitro models of retinal pigment epithelium (RPE): Xanthophyll uptake, metabolism and pathway‐specific gene expression
Author(s) -
Marisiddaiah Raju,
Gong Xiaoming,
Wiener Doris,
Rubin Lewis P
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.39.5
Subject(s) - retinal pigment epithelium , microbiology and biotechnology , zeaxanthin , retinal , lutein , gene expression , biology , xanthophyll , induced pluripotent stem cell , cellular model , cell culture , chemistry , gene , biochemistry , in vitro , carotenoid , genetics , embryonic stem cell
Purpose Dietary lutein (LUT) & zeaxanthin (ZEA) comprise macular pigment and may decrease risk/severity of retinal diseases through the lifespan. LUT/ZEA accumulate in RPE and protect against oxidant and photo‐damage. We established RPE cell conditions to define LUT/ZEA dynamics and study retinal pathobiology Methods Post‐confluent human RPE (ARPE‐19) cells were maintained up to 4–5wks. LUT uptake, metabolism and exchange were determined by HPLC. RPE genes were analyzed by qRT‐PCR and western blotting. Results ARPE cells adopt different phenotypes depending on culture conditions and duration. We defined ‘early’ (2–5d) and ‘late’ (4–5wk) cells. LUT accumulates in time‐ and dose‐dependent manners; uptake remains unsaturated for ≥72h; cellular LUT also shows a slow, constant exchange. LUT treatment also differently alters gene expression, including receptors, carotenoid cleavage enzymes, metabolic genes, and xanthophyll binding proteins. At both timepoints, ARPE cells express CMO2>>CMO1. Conclusion ARPE‐19 cells show LUT uptake, metabolism, transport and downstream gene effects. Our findings support the role of CMO2 in LUT metabolism. ‘Early’ (maturing) ARPE‐19 cells are a useful model to study mechanisms of LUT/ZEA in RPE maturation and stress‐inducible retinal pathologies. Grant Funding Source : NIH, USF, Abbott Nutrition