Chemogenetic activation induces persistent transcriptomic remodeling and functional plasticity in cultured astrocytes

Astrocytes are essential regulators of neuronal function and brain homeostasis. Recent methodological advances have increasingly revealed their active roles through precise manipulation of astrocyte function in the brain. While chemogenetic strategies, such as Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), have been widely used to recapitulate endogenous G-protein-coupled receptors (GPCRs) signaling and selectively modulate astrocyte activity, the molecular mechanisms accompanying DREADD activation remain incompletely understood. Here, we characterized the transcriptional responses of cultured cortical astrocytes and found that DREADD activation induces profound changes in astrocytic gene expression profiles. Activation of Gi-, Gq-, and Gs-coupled DREADDs elicited distinct transcriptomic responses. Transcription factor activity profiling further revealed that each DREADD subtype selectively modulates a distinct set of transcription factors that collectively shape astrocytic transcriptomic responses, thereby indicating subtype-specific transcriptional mechanisms. Importantly, DREADD activation induced persistent changes in the astrocytic transcriptome that remained detectable even three days after stimulation. These transcriptomic alterations were associated with sustained changes in astrocytic calcium responses to extracellular ATP, indicating plastic changes in astrocytic physiological function. Together, these findings provide a molecular framework for interpreting astrocytic DREADD manipulations and reveal a mechanistic basis for functional plasticity and heterogeneity of astrocytes.