[HTML][HTML] Chemical chaperone TUDCA preserves cone photoreceptors in a mouse model of Leber congenital amaurosis
Purpose.: Mutations in either retinoid isomerase (RPE65) or lecithin-retinol acyltransferase
(LRAT) lead to Leber congenital amaurosis (LCA). By using the Lrat–/–mouse model,
previous studies have shown that the rapid cone degeneration in LCA was caused by
endoplasmic reticulum (ER) stress induced by S-opsin aggregation. The purpose of this
study is to examine the efficacy of an ER chemical chaperone, tauroursodeoxycholic acid
(TUDCA), in preserving cones in the Lrat–/–model. Methods.: Lrat–/–mice were systemically …
(LRAT) lead to Leber congenital amaurosis (LCA). By using the Lrat–/–mouse model,
previous studies have shown that the rapid cone degeneration in LCA was caused by
endoplasmic reticulum (ER) stress induced by S-opsin aggregation. The purpose of this
study is to examine the efficacy of an ER chemical chaperone, tauroursodeoxycholic acid
(TUDCA), in preserving cones in the Lrat–/–model. Methods.: Lrat–/–mice were systemically …
Abstract
Purpose.: Mutations in either retinoid isomerase (RPE65) or lecithin-retinol acyltransferase (LRAT) lead to Leber congenital amaurosis (LCA). By using the Lrat–/–mouse model, previous studies have shown that the rapid cone degeneration in LCA was caused by endoplasmic reticulum (ER) stress induced by S-opsin aggregation. The purpose of this study is to examine the efficacy of an ER chemical chaperone, tauroursodeoxycholic acid (TUDCA), in preserving cones in the Lrat–/–model.
Methods.: Lrat–/–mice were systemically administered with TUDCA and vehicle (0.15 M NaHCO 3) every 3 days from P9 to P28. Cone cell survival was determined by counting cone cells on flat-mounted retinas. The expression and subcellular localization of cone-specific proteins were analyzed by western blotting and immunohistochemistry, respectively.
Results.: TUDCA treatment reduced ER stress and apoptosis in Lrat–/–retina. It significantly slowed down cone degeneration in Lrat–/–mice, resulting in a∼ 3-fold increase in cone density in the ventral and central retina as compared with the vehicle-treated mice at P28. Furthermore, TUDCA promoted the degradation of cone membrane–associated proteins by enhancing the ER-associated protein degradation pathway.
Conclusions.: Systemic injection of TUDCA is effective in reducing ER stress, preventing apoptosis, and preserving cones in Lrat–/–mice. TUDCA has the potential to lead to the development of a new class of therapeutic drugs for treating LCA.
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