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Hazardous effects of an effluent from the chrome plating industry were examined by exposing transgenic Drosophila melanogaster (hsp70-lacZ) to various concentrations (0.05, 0.1, 1.0, 10.0, and 100.0 [micro]L/mL) of the [...]

Parkinson's disease (PD) is one of the most common neurodegenerative disorders with limited clinical interventions. A number of epidemiological as well as case-control studies have revealed an association between pesticide exposure, especially of paraquat (PQ) and occurrence of PD. Hsp70, a molecular chaperone by function, has been shown as one of the modulators of neurological disorders. However, paucity of information regarding the protective role of Hsp70 on PQ-induced PD like symptoms led us to hypothesize that modulation of hsp70 expression in the dopaminergic neurons would improve the health of these cells. We took advantage of Drosophila, which is a well-established model for neurological research and also possesses genetic tools for easy manipulation of gene expression with limited ethical concern. Over-expression of hsp70 was found to reduce PQ-induced oxidative stress along with JNK and caspase-3 mediated dopaminergic neuronal cell death in exposed organism. Further, anti-apoptotic effect of hsp70 was shown to confer better homeostasis in the dopaminergic neurons of PQ-exposed organism as evidenced by their improved locomotor performance and survival. The study has merit in the context of human concern since we observed protection of dopaminergic neurons in PQ-exposed organism by over-expressing a human homologue of hsp70, HSPA1L, in these cells. The effect was parallel to that observed with Drosophila hsp70. These findings reflect the potential therapeutic applicability of hsp70 against PQ-induced PD like symptoms in an organism. [ABSTRACT FROM AUTHOR]

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 ( mth 1 ), which is associated with aging, has a role in preventing dopaminergic neuronal cell death in PQ-exposed organism. Exposed mth 1 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 mth 1 flies protects the organism from PQ-induced damage, which may be causally linked to a common mechanism for PQ-induced neurodegeneration. [ABSTRACT FROM AUTHOR]