Abstract
Abstract: :
Purpose: Recent studies show evidence that retinal pigment epithelial cells (RPE) undergo apoptosis in human age-related macular degeration (AMD) and retinal dystrophies. The inhibition of apoptosis may aid in the treatment of such diseases. Tauroursodeoxycholic acid (TUDCA), a bile acid, prevents apoptosis of neuronal cells in animal models of Huntington's Disease. We sought to determine whether TUDCA also prevents apoptosis in RPE-like cells. Methods: Cells derived from RPE carcinomas were pre-treated for 20 hours with 200 uM of TUDCA. The media was removed and replaced with either serum-free or full media containing 200 uM of TUDCA. Apoptosis was induced through serum starvation and/or oxidative damage by incubation with 300 uM of tert-butylhydroperoxide (tBH). After 24 hours, cells were harvested for analysis. Apoptosis was assessed using a modified TUNEL assay. DNA was extracted using a Qiagen kit and electrophoresed on a 1.8% agarose gel to determine if DNA laddering occurred. Results: Cells that were treated with TUDCA had fewer TUNEL-positive cells than those that were not. DNA laddering was apparent in samples from cultures undergoing oxidative stress and starvation. Cells that were incubated with TUDCA had diminished or non-existent DNA laddering. Conclusions: Our DNA laddering and TUNEL analyses show that TUDCA is effective in stopping or slowing induced apoptosis in RPE-like cells. Bile acids offer advantages as potential therapeutic agents for AMD and retinal dystrophies as they are nontoxic, FDA approved, easy to administer, and inexpensive.
Keywords: retinal pigment epithelium • cell death/apoptosis • pharmacology