1,4-dihydroxy-2-naphthoic acid prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced motor function deficits

Area of Science:

• Neuroscience
• Microbiology
• Pharmacology

Background:

• Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neuron loss, with largely unknown causes.
• The gut microbiome and its metabolites are increasingly implicated in PD pathogenesis and progression.

Purpose of the Study:

• To investigate the neuroprotective effects of 1,4-dihydroxy-2-naphthoic acid (1,4-DHNA), a gut bacteria-derived metabolite, against MPTP-induced motor deficits in a rodent model.
• To explore the role of the aryl hydrocarbon receptor (AhR) in mediating these protective effects.

Main Methods:

• Male C57BL/6 mice were treated with 1,4-DHNA or its AhR-inactive isomer 3,7-DHNA for 3 weeks prior to MPTP administration.
• Motor function was assessed using motor pole, adhesive strip removal, balance beam, and stride length tests.

Main Results:

• Both 1,4-DHNA and 3,7-DHNA ameliorated MPTP-induced motor deficits in the motor pole and adhesive strip tests.
• 1,4-DHNA significantly improved balance beam performance and completely prevented MPTP-induced stride length reduction.
• 3,7-DHNA showed only partial effects on stride length and did not improve balance beam performance, suggesting AhR-dependent and independent mechanisms.

Conclusions:

• Gut microbiota metabolites like 1,4-DHNA may offer a therapeutic strategy for mitigating motor deficits in Parkinson's disease.
• The gut microbiome plays a crucial role in PD development and offers potential avenues for intervention.
• 1,4-DHNA's therapeutic effects involve multiple molecular pathways, with AhR partially mediating gait and bradykinesia improvements but not fine motor skills.