Effect of Pulsed Low-Level Lasers on Adult versus Neonatal Human Retinal Pigment Epithelial Cells: An In-vitro Study


Purpose: To investigate the short-term effects of low-level lasers (LLLs; also known as low-power laser therapy) on the structure, genetic, and phenotype of cultured human retinal pigment epithelial (hRPE) cells from both adult and neonatal sources.

Methods: Cultivated adult and neonatal hRPE cells were irradiated with two types of LLL (630 nm and 780 nm), 1 min daily for five consecutive days.

Results: An increase in doubling time was observed in 630 nm-irradiated adult hRPE cells (P = 0.032). The gene expression profile revealed increased expression of retinoid isomerohydrolase RPE65 (RPE65) (P < 0.01 for 630 nm laser, P < 0.001 for 780 nm laser) and nestin (NES) (P < 0.01 for 630 nm laser) in neonatal hRPE cells, upregulation of RPE65 (P < 0.001 for 780 nm laser) and paired box 6 (PAX6) (P < 0.001 for 780 nm laser) genes in adult hRPE cells, and reduced expression of actin alpha 2 (ACTA2) in 780 nm-irradiated adult hRPE cells (P < 0.001). Except for the significant increase of


Alpha-smooth Muscle Actin, Human Retinal Pigment Epithelial Cells, Low-level Laser, PAX6, Photobiomodulation, RPE65

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