A mutation in Drosophila methuselah resists paraquat induced Parkinson-like phenotypes

Parkinson's disease (PD) is a prevalent and devastating neurodegenerative disorder having limited cure options and strong association with the loss of dopaminergic neurons in the substantia nigra region of the mid brain. Etiology of PD includes both genetic and environmental factors. Paraquat (PQ), a widely used herbicide, is known to be associated with pathogenesis of PD. We report that a mutation in Drosophila methuselah (mth1), which is associated with aging, has a role in preventing dopaminergic neuronal cell death in PQ-exposed organism. Exposed mth1 flies exhibit significant resistance against PQ-induced Parkinson's phenotypes and behavior in terms of oxidative stress, dopaminergic neuronal degeneration, locomotor performance, dopamine content, phosphorylated JNK, pFOXO, Hid, and cleaved caspase-3 levels. Conversely, over-expression of mth in dopaminergic neurons makes the exposed organism more vulnerable to oxidative stress, neuronal cell death, and behavioral deficit. The study suggests that lesser activation of JNK-mediated apoptosis in dopaminergic neurons of exposed mth1 flies protects the organism from PQ-induced damage, which may be causally linked to a common mechanism for PQ-induced neurodegeneration.