Dedifferentiation of the retinal pigment epithelium compared to the proliferative membranes of proliferative vitreoretinopathy.
OBJECTIVE
To examine the gene expression for melanogenesis of retinal pigment epithelial cells during dedifferentiation and to compare the condition to that of eyes obtaining anatomical success after surgery for proliferative vitreoretinopathy.


METHODS
Gene expression for melanogenesis was determined by reverse transcriptase-polymerase chain reaction of tyrosinase and tyrosinase-related protein-1 genes in normal and cultured retinal pigment epithelial cells and in proliferative membranes in patients with proliferative vitreoretinopathy.


RESULTS
Gene expression for melanogenesis was classified into three types during dedifferentiation of retinal pigment epithelial cells: (1) tyrosinase-related protein-1 gene expression, (2) tyrosinase and tyrosinase-related protein-1 gene expression and (3) no expression of these genes. The expression of these genes were maintained better in mediums with basic fibroblast growth factor than in medium without basic fibroblast growth factor. Of the anatomically unsuccessful patients with proliferative vitreoretinopathy treated by surgery, 76.9% showed both tyrosinase and tyrosinase-related protein-1 gene expression; only 20% of the anatomically successful patients showed the gene expression.


CONCLUSIONS
We reported three different conditions of retinal pigment epithelial cells based on gene expression for melanogenesis during dedifferentiation. The different condition of the retinal pigment epithelial cells may have some relationship to the anatomical results for proliferative vitreoretinopathy surgery.
Abe
T
T
Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Miyagi, Japan. toshi@oph.med.tohoku.ac.jp
Sato
M
M
Tamai
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D002648:Child; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D008297:Male; D008543:Melanins / Q000096:biosynthesis; D008562:Membrane Glycoproteins; D008566:Membranes / Q000201:enzymology; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000201:enzymology*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018630:Vitreoretinopathy, Proliferative / Q000201:enzymology* / Q000473:pathology
C020932:11-cis-retinal-binding protein; D002352:Carrier Proteins; D017931:DNA Primers; D008543:Melanins; D008562:Membrane Glycoproteins; D011506:Proteins; D012333:RNA, Messenger; D007633:Keratins; D010088:Oxidoreductases; C489799:TYRP1 protein, human; C064056:tyrosinase-related protein-1; D014442:Monophenol Monooxygenase