MULTIMODAL MRI AND METABOLOMICS REVEAL NEUROPROTECTIVE EFFECTS OF NLRP3 INFLAMMASOME INHIBITION IN A PROGRESSIVE MOUSE MODEL OF MULTIPLE SCLEROSIS

Background: Disease-modifying therapies control relapsing-remitting multiple sclerosis but offer limited benefit in secondary progressive disease, highlighting the need for targets that drive persistent central nervous system inflammation and neurodegeneration. The NLRP3 inflammasome is implicated in inflammatory signalling, but its relationship to progression is not fully resolved.

Aims: To assess NLRP3 inflammasome involvement in experimental autoimmune encephalomyelitis (EAE) and test whether selective NLRP3 inhibition improves CNS metabolomics and structure.

Methods: EAE mice received vehicle or MCC950, with naive controls. NLRP3 pathway and microglial activation transcripts were measured by quantitative PCR. Diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) were used to evaluate neuroinflammation and neurometabolic disturbances in the EAE model. Targeted liquid chromatography tandem mass spectrometry quantified metabolites in CNS tissue and plasma.

Results: The mRNA levels of NLRP3, caspase-1, IL-1β, and Iba-1 were significantly increased in CNS tissues of EAE mice that were normalised following MCC950 treatment. DTI revealed reductions in FA and AD, alongside increased RD and MD in white matter regions, indicative of demyelination and axonal injury in EAE animals, which were notably reversed in MCC950-treated mice. MRS and LC-MS/MS confirmed decreased NAA and showed elevated levels of choline and myo-inositol, consistent with demyelination and gliosis in CNS tissues of EAE mice. These pathological metabolite elevations were substantially reduced in the MCC950-treated group.

Conclusion: Integrated MRI, spectroscopy, and metabolomics provide convergent, quantitative biomarkers of EAE pathology and support NLRP3 inflammasome inhibition as a promising therapeutic approach for progressive MS.