Chronic oral arsenic exposure and Tau protein phosphorylation at Ser 262

Background: It is estimated that around 140 million people are drinking highly contaminated water with arsenic (As) as a natural earth’s crust component. On the other hand, the prevalence of neurodegenerative disorders especially Alzheimer disease is constantly increasing. The aim of the present study was to investigate the correlation between oral arsenic trioxide exposure and its impact on tau protein phosphorylation at Ser262.Methods: Fifty-four male mice were randomly divided into three groups and freely accessed to food and contaminated water to 1 and 10ppm arsenic trioxide for 3 months except for control subjects. At the end of each month As concentration and Tau phosphorylation were checked with graphite furnace atomic absorption spectrometer and western blot analysis, respectively.Results: Surprisingly it was observed that the amount of measured brain arsenic in 10ppm exposed subjects was significantly increased after 3 months (p value˂0.0001). Although significant changes in tau phosphorylation were not seen in 1 ppm exposed subjects, it was observed that Ser262 phosphorylation significantly increased after 2 and 3 months in the 10ppm group (p value<0.05).Conclusion: Our results demonstrated that arsenic accumulated in the brain time-dependently and increase Ser262 tau phosphorylation which is very important in several tauopathies. In conclusion, it could be inferred that environmental arsenic exposure even at very low concentrations could be considered as a reason for increasing the risk of developing neurodegenerative disease.

کلیدواژه ها:

Arsenic ، Tau ، Phosphorylation ، Neurodegenerative disease ، Alzheimer ، Water contamination