OBJECTIVE: The aim of this study was to identify the presence of retinoid acid receptors in cultured human scleral fibroblasts and the effect of retinoic acid (RA) on the regulation of cell growth. METHODS: Human scleral fibroblasts from three donors were isolated and cultured in Dulbecco Modified Ealge's Medium. Cells from the third or fifth generation were used in the present study. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was used to detect the expression of retinoid acid receptor subtypes in the fibroblasts. RA was added to the culture medium at concentrations of 0.01, 0.10, 1.00, 10.00 and 100.00 nmol/L, separately. Cells were counted and statistically analyzed six days after being treated with RA. Each strain of the cells was examined three times. RESULTS: Cultured fibroblasts mainly showed a bipolar or spindle-shaped morphology with an average time of 2 to 3 days for each division. RT-PCR showed mRNA expression of six subtypes of RA receptors (RAR alpha, RAR beta, RAR gamma, RXR alpha, RXR beta, and RXR gamma). The proliferation of scleral fibroblasts was inhibited by 2.2%, 17.6%, 37.6%, 43.8% and 63.2% following the treatment with 0.01, 0.10, 1.00, 10.00 and 100.00 nmol/L of RA, respectively. Cell proliferation in RA-treated samples reduced significantly as compared to the control samples (P < 0.05) when the RA concentration exceeded 0.10 nmol/L. CONCLUSIONS: Six retinoid acid receptor subtypes are present in cultured human scleral fibroblasts and the growth of scleral fibroblasts was inhibited significantly by retinoic acid. These findings indicate that the sclera is a potential site of action for the retinoid acid during progression of myopia.
OBJECTIVE: The aim of this study was to identify the presence of retinoid acid receptors in cultured human scleral fibroblasts and the effect of retinoic acid (RA) on the regulation of cell growth. METHODS:Human scleral fibroblasts from three donors were isolated and cultured in Dulbecco Modified Ealge's Medium. Cells from the third or fifth generation were used in the present study. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was used to detect the expression of retinoid acid receptor subtypes in the fibroblasts. RA was added to the culture medium at concentrations of 0.01, 0.10, 1.00, 10.00 and 100.00 nmol/L, separately. Cells were counted and statistically analyzed six days after being treated with RA. Each strain of the cells was examined three times. RESULTS: Cultured fibroblasts mainly showed a bipolar or spindle-shaped morphology with an average time of 2 to 3 days for each division. RT-PCR showed mRNA expression of six subtypes of RA receptors (RAR alpha, RAR beta, RAR gamma, RXR alpha, RXR beta, and RXR gamma). The proliferation of scleral fibroblasts was inhibited by 2.2%, 17.6%, 37.6%, 43.8% and 63.2% following the treatment with 0.01, 0.10, 1.00, 10.00 and 100.00 nmol/L of RA, respectively. Cell proliferation in RA-treated samples reduced significantly as compared to the control samples (P < 0.05) when the RA concentration exceeded 0.10 nmol/L. CONCLUSIONS: Six retinoid acid receptor subtypes are present in cultured human scleral fibroblasts and the growth of scleral fibroblasts was inhibited significantly by retinoic acid. These findings indicate that the sclera is a potential site of action for the retinoid acid during progression of myopia.