AKT/FOXOγA PATHWAY: SIGNALING TARGET FOR α-SYNUCLEIN OVEREXPRESSION AND MANEB MEDIATED NEUROTOXICITY

CONDE, M.; IGLESIAS GONZÁLEZ, P.A.; ALZA, N.P.; BENZI JUNCOS, O.N.; URANGA, R.; SALVADOR, G.

Congreso; 54 Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2018

α-synuclein (α-syn) overexpression and manganese-based pesticides such as Maneb (Mb) have been both implicated as etiological factors ofParkinson?s disease. We have previously reported the neuroprotective role of Akt/FoxOγa in amyloid ȕ- and Fe-induced injury. In this work, westudied the role of the above-mentioned pathway in the effect of Mb and/or α-syn overexpression on IMR-32 human neuroblastoma cells. Forthis purpose, we exposed these neurons for different times (24-72 h) to increasing Mb concentrations (6-β4 μM) and evaluated the redox status,Akt/FoxO3a subcellular localization and phosphorylation levels, and cell viability. The same parameters were evaluated in neurons stablyoverexpressing the wild type form of α-syn and exposed to either Mb or its vehicle.Mb exposure provoked a time- and concentration-dependent decrease in neuronal viability. This cytotoxic effect was mediated by the increase inreactive oxygen species (ROS), lipid peroxides and membrane cell permeability (LDH release). Intriguingly, Mb exposure in α-synoverexpressing neurons showed decreased ROS content and LDH release, with no changes in lipid peroxides. Mb was also found to inducechanges in α-syn aggregation and phosphorylation, as measured with the intracellular probe Thioflavin S and by immunocytochemistry.On the other hand, Mb exposure and α-syn overexpression unconnectedly triggered the increase in Akt and FoxO3a nuclear localization.However, Mb exposure in α-syn overexpressing neurons enhanced FoxO3a nuclear localization without increasing cell death. We hypothesizethat FoxOγa might be an α-syn target related with its unexpected protective role.