IL-10-STAT3-Dependent Transcriptional Regulation in Microglia: Alzheimer's Disease and Neuroinflammation.

Interleukin-10 (IL-10) is a key immunoregulatory cytokine that suppresses inflammatory gene transcription in myeloid cells through signal transducer and activator of transcription 3 (STAT3). In Alzheimer's disease and neuroinflammation, microglia express IL10ra and exhibit STAT3 Tyr705 phosphorylation following IL-10 stimulation, indicating IL-10 receptor-dependent STAT3 activation. Recent studies demonstrate that IL-10 induces promoter-selective STAT3-dependent transcriptional regulation in microglia through chromatin-associated mechanisms, whereas gp130-dependent cytokines activate STAT3 to induce transcription of defined target genes, including Socs3 and Ccl5. Following IL-10 receptor activation, STAT3 binds regulatory regions of inflammatory genes, including Il1b, Tnf, Il6, and Nlrp3, with reduced RNA polymerase II and NF-κB binding. IL-10-dependent transcriptional repression involves formation of a nuclear SHIP1-STAT3 complex, localization of histone deacetylase (HDAC)1 and HDAC2 to H3K4me1-enriched enhancer regions, reduced H3K27ac, and decreased chromatin accessibility at regulatory regions of inflammatory genes. IL-10-activated STAT3 induces Socs3, which regulates JAK1 and TYK2 activity and STAT3 phosphorylation. Impairment of IL-10 receptor signaling in microglia is associated with increased inflammatory gene expression, enhanced inflammasome-related transcription, demyelination, and amyloid accumulation. This review focuses on IL-10-STAT3-dependent transcriptional regulation in microglia, including receptor signaling, chromatin-associated mechanisms, and disease-associated gene expression in Alzheimer's disease and neuroinflammation.