Abstract
Purpose :
The immunoproteasome is very interesting with regard to cataract, as it like the constitutive proteasome, breaks down damaged and aggregated proteins into short peptides. However, the two proteasome types produce different types of peptides.
In a recently published study from our group, we showed that oxidative stress increases immunoproteasome expression in both cultured human lens epithelial cells and in human lens material.
The purpose of the study is to investigate if and how age and type of cataract affect immunoproteasome and constitutive proteasome expression.
Methods :
Expression of the immunoproteasome and the constitutive proteasomesubunits ß5i/ß5 were studied by using immunoprecipitation and western blotting in lens epithelium and in the lens fibers derived from cataract surgery from 32 patients of different age groups and cataract types. The age groups ranged from 49-60, 61–70, 71-80, 81-94 years of age. Samples pooled from all 32 patients were used as reference sample.
Results :
Immunoproteasome as well as constitutive proteasome subunit protein expression, showed a significant increase with increasing age. The immunoproteasome expression were significantly increased by 60%, in the age group 81-94 years of age compared to the age group 49-60 years (P = 0.008). For the age groups 61-70 and 71-80 years, the increase was 34% (P = 0.239) and 21% (P = 0.517) respectively. The constitutive proteasome were significantly increased by 158% in the age group 71-80 years of age compared to the age group 49-60 years (P = 0.015). For the age groups 61-70 and 81-95 years, the increases were 84% (P = 0.054) and 96% (P = 0.734) respectively.
Statistical analysis was performed using ANOVA with Dunnett post hoc.
Conclusions :
The present findings indicate that older age have an increased demand for both immunoproteasome and constitutive proteasome management in the human lens.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.