The NLRP3 inflammasome: A central player in multiple sclerosis

Multiple sclerosis (MS) is a neurological autoimmune condition associated with many symptoms including spasticity, pain, limb numbness and weakness. It is characterised by inflammatory demyelination and axonal degeneration of the brain and spinal cord. A range of disease-modifying therapies (DMTs) are available to suppress inflammatory disease activity in MS, however, there is a pressing need for new therapeutic avenues as DMTs have a limited ability to suppress confirmed disability progression. A body of literature indicates that innate immune inflammation is linked to MS progression. The nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing protein 3 (NLRP3) inflammasome has a well-established function in innate immunity which is closely associated with the pathogenesis of neuroinflammatory conditions. Evidence suggests that the inflammasome may be a therapeutic target in disorders such as MS and at present, inhibitors of the NLRP3 inflammasome are in pre-clinical development. Therefore, this review systematically highlights the pathogenic role of inflammasomes in MS, presenting an overview of research evidence linking inflammasome-related polymorphisms to MS susceptibility, and gathering evidence investigating NLRP3 biomarkers in MS. The role of the NLRP3 inflammasome in murine models of MS is furthermore discussed. Finally, a significant component of this review focuses on evidence that NLRP3 signalling components are novel drug targets in MS. Overall this review defines the role of the inflammasome in MS pathogenesis and identifies inflammasome inhibitor targets that warrant full investigation in MS and related disorders.