Acute and chronic metal exposure impairs locomotion activity in Drosophila melanogaster: a model to study Parkinsonism.

The biometals iron (Fe), manganese (Mn) and copper (Cu) have been associated to Parkinson's disease (PD) and Parkinsonism. In this work, we report for the first time that acute (15 mM for up to 5 days) or chronic (0.5 mM for up to 15 days) Fe, Mn and Cu exposure significantly reduced life span and locomotor activity (i.e. climbing capabilities) in Drosophila melanogaster. It is shown that the concentration of those biometals dramatically increase in Drosophila's brain acutely or chronically fed with metal. We demonstrate that the metal accumulation in the fly's head is associated with the neurodegeneration of several dopaminergic neuronal clusters. Interestingly, it is found that the PPL2ab DAergic neuronal cluster was erode by the three metals in acute and chronic metal exposure and the PPL3 DAergic cluster was also erode by the three metals but in acute metal exposure only. Furthermore, we found that the chelator desferoxamine, ethylenediaminetetraacetic acid, and D: -penicillamine were able to protect but not rescue D. melanogaster against metal intoxication. Taken together these data suggest that iron, manganese and copper are capable to destroy DAergic neurons in the fly's brain, thereby impairing their movement capabilities. This work provides for the first time metal-induced Parkinson-like symptoms in D. melanogaster. Understanding therefore the effects of biometals in the Drosophila model may provide insights into the toxic effect of metal ions and more effective therapeutic approaches to Parkinsonism.