Elevated concentrations of amyloid-β oligomers and their proapoptotic effects on age-related cataract

Abstract

Recently, amyloid-β oligomers (AβOs) have been studied as the primary pathogenic substances in Alzheimer's disease (AD). Our previous study revealed that the Aβ expression level is closely related to ARC progression. Here, we demonstrated that the accumulation of AβOs in the lens epithelium of age-related cataract (ARC) patients increased during ARC progression and that this alteration was consistent with the changes in mitochondrial function, oxidative stress, and cellular apoptosis. In vitro, human lens epithelial cells (HLECs) treated with AβOs exhibited Ca²⁺ dyshomeostasis, impaired mitochondrial function, elevated oxidative stress levels, and increased apoptosis. Moreover, the proapoptotic effect of AβOs was alleviated after the uptake of mitochondrial Ca²⁺ was inhibited. These results establish that AβOs may promote HLEC apoptosis by inducing mitochondrial Ca²⁺ overload, thus preliminarily revealing the possible association between the accumulation of AβOs and other pathological processes in ARC.