Abstract
Purpose :
To explore how monochromatic light-emitting diodes (LEDs) modulate the tight-junction (T-J) formation in human corneal epithelial cells (HCEs).
Methods :
HCEs were cultivated in DMEM/F12 with 10% FBS and exposed to UV-LED (360 nm), violet-LED (420 nm), blue-LED (470 nm), green-LED (530 nm), amber-LED (590 nm), deep red (DR)-LED (660 nm), and far red (FR)-LED (740 nm) at 10 J/cm2/day for up to 2 days, respectively. Cell viability was analyzed by CCK-8 cell proliferation assay. Expression and distribution of endogenous ZO-1 in HCEs were analyzed by immunoblotting and immunofluorescent staining. Intracellular cAMP level was determined by cyclic AMP ELISA kit.
Results :
There was no significant difference in HCE cell viability following 1-day exposure to all LEDs. However, 2-day exposure to UV-LED significantly suppressed HCE cell viability. In contrast, 2-day exposure to green-LED, amber-LED, DR-LED, and FR-LED did not interfere with HCE cell viability. A 1-day exposure to UV-LED, violet-LED, and blue-LED enhanced the product of intracellular cAMP and promoted the T-J formation, but did not alter protein expression of endogenous ZO-1. However, 2-day exposure to UV-LED significantly reduced protein express of endogenous ZO-1. There was no alteration in both T-J formation and endogenous ZO-1 protein expression following 2-day exposure to green-LED, amber-LED, DR-LED, and FR-LED.
Conclusions :
Promotion of the T-J formation in human corneal epithelial cells by non-lethal exposure of short-wavelength monochromatic LEDs might result from increased intracellular cAMP level.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.