Effect of Flavin Adenine Dinucleotide on Ultraviolet B Induced Damage in Cultured Human Corneal Epithelial Cells

Abstract

This study evaluated the eŠects of ‰avin adenine dinucleotide (FAD) on ultraviolet B (UV-B)-induced damage in cultured human corneal epithelial (HCE-T) cells. The cultured HCE-T cells were treated with 0.003125 0.05％ FAD before exposure to 80 mJ/cm 2 UV-B. Cell viability was measured 24 h after UV-B irradiation using the MTS assay. Reactive oxygen species (ROS) were detected 30 min after UV-B irradiation using 5-(and-6)-chloromethyl-2',7'-dichlorodihydro‰uorescein diacetate acetyl ester. Apoptosis was evaluated 4 h after UV-B irradiation in the caspase-3/7 activity assay. UV-B irradiation reduced cell viability and stimulated ROS production and caspase-3/7 activity in HCE-T cells. Pretreatment of UV-B irradiated HCE-T cells with FAD signiˆcantly attenuated cell viability reduction and inhibited the stimulation of both ROS production and caspase-3/7 activity due to UV-B exposure compared with those with vehicle (0 ％ FAD). These results clariˆed that FAD inhibits ROS-mediated apoptosis by UV-B irradiation in HCE-T cells and suggest that FAD may be eŠective as a radical scavenger in UV-B-induced corneal damage.

Prdx6 is required to protect human corneal epithelial cells against ultraviolet B injury

“…The high level of intracellular ROS, which is the product of oxidative stress in the cornea induced by UV-B, resulted in ER dysfunction and cell apoptosis. 30,31 BiP/glucose-regulated protein 78 (Grp78) was confirmed as an ER stress-related marker. The current study showed an opposite trend between the expression of Prdx6 and Grp78, which indicated that downregulated expression of Prdx6 resulted in high ER stress.…”

“…The current study showed an opposite trend between the expression of Prdx6 and Grp78, which indicated that downregulated expression of Prdx6 resulted in high ER stress. Scoltock et al 30 and Sakamoto et al 31 reported that high ER stress could cause apoptosis. Our results of increased expression of Grp78 in HCECs with decreased Prdx6 expression are consistent in demonstrating increased apoptosis.…”