DJ-1 protein protects dopaminergic neurons against 6-OHDA/MG-132-induced neurotoxicity in rats.

Parkinson disease (PD) is the second most common neurodegenerative disease, and it cannot be completely cured by current medications. In this study, DJ-1 protein was administrated into medial forebrain bundle of PD model rats those had been microinjected with 6-hydroxydopamine (6-OHDA) or MG-132. We found that DJ-1 protein could reduce apomorphine-induced rotations, inhibit reduction of dopamine contents and tyrosine hydroxylase levels in the striatum, and decrease dopaminergic neuron death in the substantia nigra. In 6-OHDA lesioned rats, uncoupling protein-4, uncoupling protein-5 and superoxide dismutase-2 (SOD2) mRNA and SOD2 protein were increased when DJ-1 protein was co-injected. Simultaneously, administration of DJ-1 protein reduced α-synuclein and hypoxia-inducible factor 1α mRNA and α-synuclein protein in MG-132 lesioned rats. Therefore, DJ-1 protein protected dopaminergic neurons in two PD model rats by increasing antioxidant capacity and inhibiting α-synuclein expression.