NLRC5-Mediated Epigenetic and Proteomic Regulation of Microglial Panoptosis Drives Neuroinflammation in Multiple...

Microglial dysfunction contributes to multiple sclerosis (MS) pathogenesis, yet the link between epigenetic regulation and inflammatory cell death (PANoptosis) remains unclear. This study explores NOD-like receptor family CARD domain containing 5 (NLRC5) as a regulator of microglial PANoptosis in MS. Transcriptomic data from experimental autoimmune encephalomyelitis (EAE) microglia (GSE253318) and GEO datasets (GSE78809, GSE154228) were integrated to identify PANoptosis-related genes. Mendelian randomization (MR) linked NLRC5 expression to proteomic targets using UK Biobank and deCODE Iceland protein quantitative trait loci (pQTLs). Methylation quantitative trait locus (mQTL) analysis assessed MS-associated CpG sites. Lipopolysaccharide (LPS)-treated BV2 microglial models were used to validate NLRC5-PANoptosome assembly via Western blot and immunofluorescence. NLRC5 was identified as a hub gene in PANoptosis-related pathways. MR suggested modest associations between NLRC5 expression and apoptotic (GABA Type A Receptor-Associated Protein (GABARAP), BR Serine/Threonine Kinase 2 (BRSK2), TNF Superfamily Member 12 (TNFSF12)) and apoptotic/necroptotic (BCL2) effectors, consistent across inverse-variance weighted (IVW), Bayesian weighted Mendelian randomization (BWMR), and generalized summary-data-based Mendelian randomization (GSMR) methods, though effect sizes were small. Hypermethylation of NLRC5 (cg04097610) showed a potential protective association with MS risk (odds ratio (OR) = 0.885, P = 0.039). In vitro, LPS stimulation upregulated NLRC5, ZBP1, ASC, and caspase-8, supporting PANoptosome activation. NLRC5 may regulate microglial PANoptosis through epigenetic and proteomic mechanisms, linking inflammatory cell death to MS progression. These findings suggest NLRC5 as a candidate regulator and potential therapeutic target, although further validation in human studies is required.