Advanced glycation end products and lipofuscin deposits share the same location in cardiocytes of the failing heart

BackgroundDisturbed glucose metabolism, particularly in diabetes type 2 (DM2), may result in advanced glycation end product (AGE) formation. One of the possible targets for this reaction is lipofuscin (LF), an intracytoplasmic garbage presumed to be a marker of physiologic and preterm aging of cells. The study was performed to seek for a relationship between AGE and LF in cardiocytes of the failing hearts.Material and methodsArchived tissue samples from 136 hearts explanted before transplantation (in 14 pts. with ischemic cardiomyopathy (CM) and DM2; 8 pts. with dilated CM and DM2; 67 non-diabetic pts. with ischemic CM; 47 non-diabetic pts. with dilated CM), 14 autopsy cases with DM2, and 20 heart donors (control group) were involved in the study. Immunohistochemical localization of AGE was applied. The coexistence of lipofuscin and AGE was studied by LF autofluorescence in AGE-positive slides.ResultsLF granules inside AGE deposits were present in all studied groups with varying frequencies, but the differences were non-significant. LF granules joined significantly with dispersed patterns of AGE i.e. diffuse and mixed, whereas coincidence of LF and AGE forming granular pattern was rare.ConclusionsWe demonstrate that LF may belong to the components of the AGE deposits. The frequency of this phenomenon is dependent on the AGE dispersion grade, but neither on diabetes nor cardiomyopathy presence.

► Advanced glycation end-products (AGE) and lipofuscin (LF) are intracellular debris.
► We seek for a relationship between AGE and LF in cardiocytes of the failing hearts.
► Insufficient hearts explanted before transplantation were involved in the study.
► AGE was localized immunohistochemically, and LF by autofluorescence.
► The co-localization of AGE and LF in cardiomyocytes was demonstrated.