The effect of neuronal conditional knock-out of peroxisome proliferator-activated receptors in the MPTP mouse model of Parkinson’s disease

Activation of peroxisome proliferator-activated receptors (PPARs), namely PPARγ and PPARδ, has been shown to provide neuroprotection in a number of neurodegenerative disorders, such as Alzheimer's and Parkinson's disease (PD). The observed neuroprotective effects in experimental models of PD have been linked to anti-oxidant and anti-inflammatory actions. This study aimed to analyze the full influence of these receptors in neuroprotection by generating a nerve cell-specific conditional knock-out of these receptors and subjecting these genetically modified mice to the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin to model dopaminergic degeneration. Mice null for both receptors show the lowest levels of tyrosine hydroxylase (TH)-positive cell bodies following MPTP administration. Presence of one or both these receptors show a trend toward protection against this degeneration, as higher dopaminergic cell immunoreactivity and striatal monoamine levels are evident. These data supplement recent studies that have elected to use agonists of the receptors to regulate immune responses. The results place further importance on the activation of PPARs and the neuroprotective roles these have in inflammatory processes linked to neurodegenerative processes.