Senescence-Related Truncation and Multimerization of Apolipoprotein A-I in High-Density Lipoprotein With an Elevated Level of Advanced Glycated End Products and Cholesteryl Ester Transfer Activity

Abstract

To compare the change in lipoprotein metabolism with aging, we analyzed the lipid and protein compositions of individual lipoprotein fractions. Healthy and nonobese elderly participants (elderly group, n = 26) had a serum lipid profile within the normal range, although slightly higher than in young participants (control group, n = 18). However, the elderly group had a twofold higher serum uric acid level and triglyceride (TG):high-density lipoprotein cholesterol ratio. The elderly group had less antioxidant ability and elevated TG content in high-density lipoprotein (HDL) with enhanced cholesteryl ester transfer activity. An elevated level of advanced glycated end products in lipoproteins and fragmentation of apoA-I were present in the elderly group, with detected lower apoA-I level and more multimerized apoA-I in HDL. The protein levels of apoA-I, apoC-III, and serum amyloid A in lipoprotein-deficient serum were increased in the elderly group.