Multiple sclerosis
Summary
Multiple sclerosis (MS) is a chronic autoimmune and neurodegenerative disease of the CNS characterized by demyelination, inflammation, axonal damage, and progressive neurological disability. Microglia play dual roles: driving lesion formation in some contexts while contributing to remyelination and repair in others.
Microglial Relevance
Microglia are the primary innate immune effectors in MS lesions. Active MS lesions show microglial activation and transition to proinflammatory states. In progressive MS, a smoldering microglial activation phenotype at lesion rims (slowly expanding lesions) is associated with disability progression. Single-cell RNA-seq of MS tissue reveals distinct microglial states including inflammatory, phagocytic, and remyelinating populations. TREM2 is implicated in promoting myelin debris phagocytosis and remyelination. CSF1R inhibitors targeting microglia are being evaluated in progressive MS. CX3CR1 and P2RY12 homeostatic markers are downregulated in active MS lesions.
Sources
- Microglia in multiple sclerosis: friend or foe? (2019)
Last reviewed: June 1, 2026