Dynamic Changes in Oxidative Stress and Epigenetic Modifications in the Ventral Mesencephalon and Striatum of MPTP-Treated Mice: Implications for Parkinson's Disease Pathogenesis.

This study investigates the effects of an acute 1-metil 4-fenil 1,2,3,6-tetraidro-piridina (MPTP) treatment, a known inducer of parkinsonism, on oxidative stress and epigenetic changes in the mouse ventral midbrain (VM) and striatum. Key markers were analyzed at 4, 8, 24, and 48 h post-injections: the hydroxylated form of the purine guanine (8-hydroxy-2'-deoxyguanosine; 8-OHdG), a marker of oxidative stress; the methylated form of cytosine (5-methylcytosine; 5-mC), associated with gene silencing; the hydroxy methylated form of cytosine (5-hydroxymethylcytosine; 5-hmC), involved in demethylation and gene regulation. The results showed a pronounced decrease in 8-OHdG levels in the VM, suggesting a rapid oxidative stress response, whereas the striatum exhibited a less pronounced response, reflecting regional differences in oxidative stress vulnerability DNA methylation patterns revealed complex and biphasic changes in 5-mC levels in the VM, contrasted with a less pronounced response in the striatum, suggesting disrupted methylation homeostasis and regional epigenetic variability. MPTP treatment also significantly reduced in 5-hmC levels in the VM, pointing to impaired active DNA demethylation and compromised epigenetic flexibility. In contrast, the striatum maintained consistently high 5-hmC levels, reflecting compensatory hydroxymethylation mechanisms specific to this region. These findings highlight pronounced regional differences in oxidative stress vulnerability and epigenetic regulation, with the VM showing heightened sensitivity to oxidative damage and impaired epigenetic flexibility. This underscores the importance of understanding the role of oxidative and epigenetic mechanisms in Parkinson's disease pathophysiology, The changes pave the way for novel therapeutic strategies targeting oxidative DNA damage and epigenetic homeostasis.