Neuroprotection in Parkinson's Disease: a Multi-directional Genetic Strategy for Maximum Protection of Dopaminergic Neurons against Parkinsonian Toxicity

The complex biology of Parkinson's disease and the obscure mechanism of dopaminergic cell death in the course of the disease indicate that multiple intracellular pathways and numerous crucial elements contribute to the demise of these neurons. Therefore, multi-factorial approaches would more likely confer long-lasting survival and potentiate the biological function of dopamine neurons. We are proposing a multi-directional strategy to protect dopamine neurons against parkinsonian toxicity that involve transcription, anti-oxidant and neurotrophic factors. Specifically, Nurr1 an important DA transcription/ anti-inflammatory factor, glutathione peroxidase-1 an anti-oxidant enzyme (GPX-1) and glial cell line-derived neurotrophic factor (GDNF) a potent neurotrophic factor have all shown their capacity for dopaminergic neuroprotection. A model we are proposing is based on dopamine neuron-astrocyte-microglia co-culture that will supply all three factors in a tripartite fashion accelerating gene-to-gene and cell-to-cell cross-talks for synergy. While microglia will overexpress Nurr1, astrocytes will act as minipumps to secrete GDNF into the medium to act on GPX-1-overexpressing dopamine neurons growing within their proximity. The neurons will ultimately be exposed to the parkinsonian neurotoxin 6-OHDA and tested for their improved survival rate in vitro and in vivo, their integration capacity to neural network and their physiological function in the midbrain circuitry.