Background: Alzheimer's disease (AD) is defined as a progressive and irreversible neurodegenerative
disorder, the onset of which is mainly characterized by decreased cognition, memory loss,
and mental confusion.
Objective: This study sought to quantify mRNA expression of the APBA2, INSR and IDE genes in brain
samples from patients with AD and controls.
Methods: We investigated the mRNA expression of the APBA2, INSR and IDE genes in 150 RNA samples
from entorhinal cortex, auditory cortex, and the hippocampus of individuals with AD and elderly
controls using real time PCR. APOE genotypes were determined by PCR-RFLP.
Results: When the total brain samples were analyzed collectively, a decrease in IDE gene expression
was found in AD patients relative to healthy elderly controls. However, when the samples were analyzed
separately according to the region of the brain, there was a significant upregulation of INSR expression
in the hippocampus and the entorhinal cortex in the AD patient group. We did not observe any statistical
differences when gene expression was compared in the different regions of the brain of AD patients.
When the E4 allele of apolipoprotein-E was considered in AD patients, the presence of this allele was
found to be associated with decreased APBA2 gene expression. The same analysis using the INSR and
IDE genes showed no significant statistical differences.
Conclusion: These results support the hypothesis that APBA2, IDE, and particularly INSR gene expression
in different areas of Alzheimer’s patient’s brains could represent new markers for use in clinical
diagnoses in the near future.