Abstract
Purpose: :
This study was designed to investigate the expression of TYR, TYRP–1, TYRP–2, P–protein and MC1R in cultured adult human retinal pigment epithelium (RPE) cells in order to determine whether the cultured human RPE cells can synthesize melanin or not.
Methods: :
RPE cells were isolated and cultured from three donor eyeballs using the methods described previously. Cells used in this study have been passaged 2–4 times. RT–PCR and Western Blot analysis were used for the detection of expression of mRNA and protein of TYR, TYRP–1, TRYP–2, P–protein and MC1R, respectively.
Results: :
Melanin content of cultured RPE cells decreased rapidly and in proportion to cell division. There was no mRNA expression of TYR, TYRP–1, TYRP–2, P–protein and MC1R in cultured RPE cells by RT–PCR and no protein expression of TYR, TYRP–1, TYRP–2 and MC1R by Western blot analysis.
Conclusions: :
No expression of TYR, TYRP–1, TYRP–2, P–protein and MC1R can be detected in cultured adult human RPE cells. These genes are essential for the synthesis of eumelanin, therefore, our results are consistent with the fact that adult human adult RPE cells do not synthesize melanin in vitro. In addition to the lacking of expression of TYR, it may also be resulted from the lacking of expression of TYRP–1, TYRP–2, P–protein and MC1R which are also essential for melanogenesis by pigment cells.
Keywords: retinal pigment epithelium • retinal degenerations: cell biology