It has recently been reported that the accumulation of amyloid β（Aβ）peptides in the human lens may be related to the onset of lens opacification, but this mechanism of Aβ accumulation is not fully understood. In this study, we investigated the changes in gene expression levels for proteins related to Aβ production（APP, BACE1 and PS）and degradation（ADAM10, NEP, ECE-1）in the lens epithelium of patient with or without dementia. The Aβ mRNA expression was determined by real-time PCR method, and samples were collected from Japanese patients taken during cataract surgery. The NEP and ECE-1 mRNA levels in the cataractous lenses of patients with dementia were significantly lower than that in patients without dementia. In conclusion, we found low levels of gene expression for proteins related to Aβ degradation in the lens epithelium of Japanese patients with dementia.
The properties of 2-amino-3-hydroxyacetophenone O-β-D-glucoside（AHAG）and 2-amino-3-hydroxyacetophenone（AHA）were investigated using UV-visible absorption spectroscopy（200～500 nm）before and after near-UV irradiation. Spectra of AHAG did not change appreciably following UV irradiation for 18 hours, whereas absorption by AHA increased at 300 nm, indicating a singlet to triplet transition. Additionally, an increase in the absorbance at 400 nm and the appearance of an apparent shoulder at ～430 nm further supported the occurrence of a singlet to triplet transition in AHA. The maximum fluorescence wavelength（480 nm）of AHAG was not altered following UV irradiation, but the intensity of AHAG fluorescence was increased up to 12-hours after irradiation and then decreased at 18 hours. By contrast, the intensity of AHA fluorescence at 480 nm was increased following near-UV irradiation for AHA, but it remained weaker than that of AHAG. These results indicate that AHAG is highly stable against near-UV irradiation.