Effects of progesterone administered after MPTP on dopaminergic neurons of male mice

Area of Science:

• Neuroscience
• Neuroprotection
• Parkinson's Disease Research

Background:

• 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) models early Parkinson's disease by damaging dopamine (DA) neurons.
• Previous studies showed progesterone neuroprotection when given before or shortly after MPTP.
• The potential for progesterone to restore DA levels later after MPTP lesioning is unknown.

Purpose of the Study:

• To investigate if progesterone administration, either 24 hours or 5 days after MPTP lesioning, can restore striatal dopamine levels in male mice.
• To assess the effects of delayed progesterone treatment on dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2), glial fibrillary acidic protein (GFAP), and brain-derived neurotrophic factor (BDNF) levels.

Main Methods:

• Male mice received MPTP injections to induce partial striatal DA neurodegeneration.
• Progesterone was administered daily for 5 days, starting either 24 hours or 5 days post-MPTP.
• Striatal DA, metabolites, DAT, VMAT2, GFAP, and BDNF levels were quantified.

Main Results:

• MPTP lesioning decreased striatal DA and its metabolites.
• Progesterone treatment initiated 24 hours after MPTP, but not 5 days after, significantly increased striatal DA and metabolite levels.
• Early progesterone treatment also corrected MPTP-induced decreases in DAT and VMAT2 binding, reduced GFAP levels, and prevented BDNF reduction.

Conclusions:

• Progesterone administered 24 hours after MPTP lesioning protects dopaminergic neurons in mice.
• Neuroprotection involves modulating neuroinflammation and brain-derived neurotrophic factor (BDNF) signaling.
• Progesterone shows potential as a disease-modifying therapy for prodromal Parkinson's disease in humans.