Abstract
Purpose:
Aquaporin 8 (AQP8) is known as a diffusion facilitator of H2O2. On the other hand, lens epithelium derived growth factor (LEDGF) is known as a stress-resistant factor against varying stress such as oxidation. We previously reported that the expression of AQP8 significantly decreased among males and correlated to the glutathione peroxidase expression among females after using an antioxidant supplement containing lutein. In this study, the changes of LEDGF expression and the correlations to AQP8 expression were investigated after using this supplement.
Methods:
15 males and 14 females with binocular cataracts of the same grade were included in the study after giving informed consent. The anterior capsule, along with lens epithelial cells, was collected as a pre-intake sample during cataract surgery. Ocuvite+ LuteinⓇ, an antioxidant supplement, was administered orally beginning the day after surgery. Six weeks later, the anterior capsule was collected as a post-intake sample during cataract surgery of the opposite eye. RNA was purified from the homogenized samples, and cDNA was reverse transcribed to measure mRNA levels. The expression levels of AQP8 and LEDGF were measured using RT-PCR.
Results:
There were no differences between the expression levels of LEDGF in the pre-intake samples and those in post-intake samples among both genders. In males, a significant positive correlation between LEDGF expression and AQP8 expression was observed in pre-intake samples (R=0.5, P<0.05) while not in post-intake samples. In females, there were no significant correlations in either pre- or post-intake samples.
Conclusions:
The results suggest that for regulating cell survival LEDGF expression corresponded with the degree of H2O2 influx through AQP8 among males. After supplement intake, the expression of AQP8 decreased with decreasing H2O2 influx thus the correlation with LEDGF became imperceptible. These results also suggest that LEDGF manifests the resistance to oxidative stress in different ways between genders, as does the antioxidant supplement.