Análise multielementar usando técnicas de XRF em cérebros de camundongos suíços utilizando o modelo experimental da Doença de Alzheimer induzida por oligômeros β-amiloide

Abstract

Alzheimer’s disease (AD) is a progressive and irreversible disorder whose pathological features include neuronal and synaptic loss. The imbalance in the homeostasis of metal ions leads to neuronal death. The metal ions may have an important impact on protein misfolding and the progression of the neurodegenerative process. However, no study analyzing the effects of single injection of β-amyloid soluble oligomers (AβOs) in the elements’ homeostasis in mice was developed. In this study, in order to evaluate the concentration and distribution of metals in brain of Swiss mice, were used TXRF and μSRXRF techniques. For this, three groups of both genders were studied and icv injections of 10 pmol of AβOs (AD10 group), 100 pmol of AβOs (AD100 group) and an equivalent volume of vehicle (control group) were made. The TXRF results showed differences in the elemental concentration in some brain regions between AD groups and control group, in both males and females. On the other hand, using the μSRXRF to compare the AD groups to the control group it was verified a decrease of iron, copper and zinc levels in the AD100 group. These alterations found with the two techniques suggest that AβOs acts quickly, even before the amyloid plaques’ formation, explaining cognitive deficits independently of amyloid plaques. This study helps to understand that this modification on elemental concentration can be influenced by AβOs.