Amyloid β1-43 accumulates in the lens epithelium of cortical opacification in Japanese patients

Abstract

PURPOSE. We investigated the accumulation of amyloid b (Aβ1-40, Aβ1-42, Aβ1-43) in the lens epithelium of patients with opacification of five different types (cortical cataract [COR]; nuclear cataract [NUC]; posterior subcapsular cataract [PSC]; retrodots [RD]; and water clefts [WC]). METHODS. Samples were collected from Japanese patients taken during cataract surgery; Aβ levels and mRNA expression were determined by ELISA and a real-time RT-PCR method, respectively. RESULTS. Levels of Aβ1-40 and Aβ1-42 in the lens epithelium of patients with COR, NUC, PSC, RD, and WC showed no significant differences in comparison with transparent lens epithelium. Levels of Aβ1-43 in the lens epithelium of patients with PSC and WC were not detected, and NUC and RD were slightly elevated. In contrast to the results in these cataract types, high Aβ1-43 levels were observed in the lens epithelium of patients with COR, and a close relationship was observed between Aβ1-43 levels and the degree of lens opacification (R ¼ 0.8229, n ¼ 6). The levels of Aβ1-43 were also higher in the lens epithelium of patients with mixed-cataract showing cortical opacification, and the Ab1-43 levels in the lens epithelium of mixed-cataract patients with cortical opacification was significantly higher than in that of mixed-cataract patients without cortical opacification. In addition, the level of an amyloid precursor protein mRNA in the lens epithelium of mixed-cataract patients with cortical opacification was significantly higher than in transparent lens and mixed-cataract patients without cortical opacification. CONCLUSIONS. We found high levels of Aβ1-43 accumulation in the lens epithelium of Japanese patients with cortical opacification.