Microglial activation signaling pathways (NF-κB, MAPK, JAK1-STAT1, and IRF3)

Microglial activation and the associated NF-κB, MAPK, JAK1-STAT1, and IRF3 signaling pathways represent the primary inflammatory response mechanism in the central nervous system. Microglia, the resident macrophages of the brain, transition from a surveillance state to an activated state in response to injury, infection, or protein aggregates like amyloid-beta (Colonna & Butovsky, 2017, Immunity). This activation triggers a cascade of intracellular signaling: the NF-κB and Mitogen-Activated Protein Kinase (MAPK) pathways drive the expression of pro-inflammatory cytokines and oxidative stress markers, while the Janus Kinase 1 (JAK1)-STAT1 and Interferon Regulatory Factor 3 (IRF3) pathways are critical for interferon-mediated responses and the maintenance of chronic neuroinflammation (Luo et al., 2022, Frontiers in Pharmacology; Qin et al., 2016, Journal of Neuroinflammation). Chronic or dysregulated activation of these pathways is a hallmark of neurodegenerative diseases such as Alzheimer's and Parkinson's, where sustained inflammation leads to neuronal damage and cognitive decline (Jefferies, 2019, Frontiers in Immunology). Therapeutic strategies often focus on modulating these pathways to shift microglia from a neurotoxic (M1) to a neuroprotective (M2) phenotype. Drugs targeting these pathways, such as JAK inhibitors or MAPK inhibitors, aim to reduce the neuroinflammatory burden, though achieving specificity within the CNS and avoiding the disruption of essential microglial functions like synaptic pruning remains a significant challenge.

Other names

Neuroinflammation pathwaysMicroglial pro-inflammatory signalingM1 microglial activation pathwaysMicroglial NF-kappaB/MAPK/JAK-STAT signaling network

Inhibition of phosphorylation, nuclear translocation, or transcriptional activity of key signaling components (such as IKK, p38, or JAK1) to suppress the production of neurotoxic inflammatory mediators and shift microglia toward a neuroprotective phenotype.