Correlation Between Accumulation of Alzheimer's Disease Markers in Brain and Retina of Individuals with Late Stage of the Disease

Abstract

This study was aimed to determine if there is a correlation between accumulation of various Alzheimer's disease (AD) markers in the brain and retina of individuals in the late stages of the disease. Characterizing the distribution and accumulation of these markers in the retina and brain may be important for early diagnosis of neurodegenerative diseases such as AD.We examined total tau and phosphorylated tau protein accumulations in different areas of the brain and in retinal tissues from aged individuals with AD in order to compare the intensity and sensitivity of these biomarkers.Tissues from the hippocampus and temporal lobe of four different cadavers were analyzed. Two cadavers had diagnosed Alzheimer's disease, and two cadavers served as a non‐AD control. We utilized cryosectioning to prepare tissue sections for immunostaining. Tissues obtained from individuals without a history of Alzheimer's disease or other types of dementia were used as negative controls. Detection of tau was performed using a primary antibody against human tau proteins and amyloid‐b, followed by a universal secondary antibody.Although the staining for AD markers was greater than controls for both brain tissues, the density was higher in the hippocampus than in the temporal lobe. The density of the total tau (TT) was greater than that of phosphorylated tau (PT181) in both the hippocampus and temporal lobe. We also found this to be the case in the brain tissues of a control, indicating that total tau may be a more sensitive biomarker than phosphorylated tau.These data demonstrate that total tau may be a stronger biomarker than phosphorylated tau in quantifying protein accumulations in the brains of Alzheimer's disease cadavers. This raises the intriguing possibility that there may be more sensitive biomarkers that can better predict the course of neurodegenerative diseases such as AD. Thus, future studies will concentrate on the accumulation of tau in the brain and retina of individuals during the earlier stages of Alzheimer's disease, as well as the sensitivity and accuracy of different biomarkers.Support or Funding InformationTouro University Nevada intramural grant.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.