AIM: To investigate if insulin can promote retinal pigment epithelial(RPE)cell proliferation and the secretion of transforming growth factor β₂(TGF-β₂).

METHODS: Human RPE cells were exposed to different concentrations insulin at different times(0 to 48 hours). We used the MTS method to test the proliferation of RPE cells. And we used the ELISA method to text the secretion of TGF-β₂ of RPE cells in various cases, and the Real-time PCR method to test the expressions of TGF-β₂ mRNA.

RESULTS: The MTS results showed that after 12 hours exposure of insulin RPE cells proliferated significantly(P<0.05). ELISA results showed that insulin can significantly promote the secretion of TGF-β₂ of RPE cells, and this process was independent of time and dose. And Real-time PCR results showed that 24 hours after the stimulation of insulin, TGF-β₂ mRNA increased significantly(P<0.01), and 10×10³U/mL insulin group, TGF-β₂ mRNA expression were significantly higher than the 0.1× 10³U/mL insulin group(P<0.01).

CONCLUSION: RPE cells are important intraocular sources of TGF-β₂, and insulin can promote the proliferation of RPE cells and the secretion of TGF-β₂ to promote myopia.