title: Efflux protein expression in human stem cell-derived retinal pigment epithelial cells.
abstract: Retinal pigment epithelial (RPE) cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP), the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC) and RPE derived from the hESC (hESC-RPE). Our findings revealed that the gene expression of ATP-dependent efflux transporters MRP1, -3, -4, -5, and p-gp fluctuated during hESC-RPE maturation from undifferentiated hESC to fusiform, epithelioid, and finally to cobblestone hESC-RPE. Epithelioid hESC-RPE had the highest expression of MRP1, -3, -4, and P-gp, whereas the most mature cobblestone hESC-RPE had the highest expression of MRP5 and MRP6. These findings indicate that a similar efflux protein profile is shared between hESC-RPE and the human RPE cell line, ARPE-19, and suggest that hESC-RPE cells are suitable in vitro RPE models for drug transport studies. Embryonic stem cell model might provide a novel tool to study retinal cell differentiation, mechanisms of RPE-derived diseases, drug testing and targeted drug therapy.
authors.affiliation: The Institute of Biomedical Technology, University of Tampere, Tampere, Finland. Kati.Juuti-Uusitalo@uta.fi
authors.forename: Kati
authors.initials: K
authors.lastname: Juuti-Uusitalo
authors.forename: Hanna
authors.initials: H
authors.lastname: Vaajasaari
authors.forename: Tuomas
authors.initials: T
authors.lastname: Ryhänen
authors.forename: Susanna
authors.initials: S
authors.lastname: Narkilahti
authors.forename: Riitta
authors.initials: R
authors.lastname: Suuronen
authors.forename: Eliisa
authors.initials: E
authors.lastname: Mannermaa
authors.forename: Kai
authors.initials: K
authors.lastname: Kaarniranta
authors.forename: Heli
authors.initials: H
authors.lastname: Skottman
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001692:Biological Transport; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D057809:HEK293 Cells; D006801:Humans; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate; D005136:Eye Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C073492:ABCC4 protein, human; C120809:ABCC5 protein, human; C114462:multidrug resistance-associated protein 3; C421109:multidrug resistance-associated protein 1