Gq Signaling in Microglia Triggers Interferon Responses and Improves Outcome After Ischemic Stroke.

Post-stroke recovery remains limited despite advances in acute reperfusion therapies, underscoring the need to better understand underlying mechanisms that shape repair. Microglia, the resident immune cells of the central nervous system, orchestrate responses to ischemic injury and critically influence neurovascular remodeling, axonal reorganization, and functional recovery. Emerging evidence indicates that inflammatory preconditioning can reprogram microglial responses to subsequent insults, yet the exact intracellular signaling pathways mediating this adaptive state remain incompletely defined. Here, we used a chemogenetic approach to selectively activate Gq signaling in microglia employing a microglia-specific DREADD mouse model. This strategy mimics Gq-coupled receptor activation in microglia in the absence of peripheral immune engagement. Pre-ischemic Gq activation significantly reduced infarct sizes at 24 h after experimental stroke in female mice and at 7 days in both sexes. Morphological analyses revealed that Gq-conditioned microglia exhibited increased structural complexity, adopting a highly ramified, spatially compact phenotype and higher CD68 expression, indicating increased phagocytic activity. Transcriptional profiling demonstrated that Gq activation primes autophagy-related defense pathways in microglia, resulting in upregulation of interferon-stimulated genes 7 days after stroke in both sexes. Together, our findings identify Gq signaling as a key modulatory pathway capable of reprogramming microglial phenotype and enhancing stroke recovery. These results highlight the plasticity of microglial signaling networks and support targeted modulation of microglial Gq pathways.