Expression of neurotrophic factors in cultured human retinal pigment epithelial cells.
OBJECTIVE
To see if cultured human retinal pigment epithelial (RPE) cells have the capacity to synthesize neurotrophins, including nerve growth factor (NGF), brain-derived growth factor (BDNF), and neurotrophin-3 (NT-3).


METHODS
Expression of mRNAs for the neurotrophins was studied by the reverse transcription polymerase chain reaction (PCR) method. Quantitative analysis of the gene expression was done by using a semiquantitative PCR method. Secretion of NGF-like immunoreactivity (NGF-LI) into the culture medium was analyzed by enzyme immunoassay (EIA).


RESULTS
Cultured human RPE cells were found to express mRNAs for NGF, BDNF and NT-3. In the conditioned culture medium of the human RPE, 9.44 +/- 0.62 pg/ml (mean +/- SEM, n = 6) NGF-LI was found. Pretreatment of human RPE cells with interleukin-l (IL-1) (20 ng/ml), phorbol myristate acetate (PMA) (100 ng/ml) or tumor necrosis factor-alpha (TNF-alpha) (40 ng/ml) was found to increase the mRNA expression of neurotrophins and also to increase secretion of NGF-LI into the culture medium.


CONCLUSIONS
Our data demonstrate that cultured human RPE cells have the capacity to synthesize neurotrophins, and that various stimulations can up-regulate gene and protein expression of NGF by these cells.
Ishida
K
K
Department of Ophthalmology and Visual Science, Kyoto University Graduate School of Medicine, Japan.
Yoshimura
N
N
Yoshida
M
M
Honda
Y
Y
Murase
K
K
Hayashi
K
K
D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D002478:Cells, Cultured; D005333:Fetus; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D020933:Neurotrophin 3; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000378:metabolism*
D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D020933:Neurotrophin 3