Detection of mRNA for proteins involved in retinol metabolism in iris pigment epithelium

Background: To investigate in iris pigment epithelium (IPE) the expression of mRNA for proteins involved in retinol metabolism we used a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) technique. Methods: RNA was prepared from freshly isolated bovine IPE and retinal pigment epithelium (RPE) cells and reverse transcribed. The expression of mRNA for cellular retinaldehyde binding protein (CRALBP), p63 (RPE63), the presumed retinal pigment epithelial membrane receptor for retinoids, and 11-cis-dehydrogenase (11cisRDH) was determined by RT-PCR using specific primers. Semi-quantitative expression data were obtained by using a series of fivefold dilution of each cDNA with a fixed number of PCR cycles. Results: Bovine IPE and RPE cells express mRNA for CRALBP, 11cis-RDH, and RPE63. The mRNA expression for CRALBP and 11cis-RDH is high and equal in both cell types. However, RPE63 mRNA expression in IPE cells is relatively low compared with the expression in RPE cells. Conclusions: The presence of mRNA for CRALBP, RPE63, and 11cisRDH suggests that IPE cells may be able to metabolize retinol.