Urine-derived stem cells ameliorates the aging of retinal pigment epithelial cells

Objective: To investigate the ameliorative effect of urine-derived stem cells (USCs) conditioned medium on the aging retinal pigment epithelial (RPE) cells and explore the underlying mechanism.

Methods: The RPE cells were cultured, and aging RPE models were prepared by D-galactose treatment and identified by β-Galactosidase staining. USCs were primarily cultured and identified by immunofluorescence staining. The proliferation and cell cycle of RPE cells in USCs conditioned medium (with USCs removal) were detected by CCK-8 assay and flow cytometry. Gene sequencing was applied to analyze the genetic variation with or without medium treatment. Bioinformatics analysis was used to investigate the biological functions of up- and downregulated differentially expressed genes after medium treatment.

Results: The cell morphology of aging RPE cells treated with the USCs medium were improved significantly and resembled normal RPE cells. In addition, the number of RPE cells increased with USCs medium, and the number of aging cells was significantly reduced after treatment with USCs medium. Moreover, the apoptosis rate of RPE cells was much lower in USCs medium group. The proportion of G1-phase RPE cells was significantly smaller and the proportion of S-phase RPE cells was significantly higher in the USCs medium group. It was found that there were 423 genes upregulated and 64 genes downregulated between the normal RPE cells and aging RPE cells, and 90 genes upregulated and 75 genes downregulated between the aging RPE cells and aging RPE cells cultured in USCs medium.

Conclusions: Our data confirmed that the USCs could positively ameliorate the aging progression of RPE cells by regulating multiple gene network.