Astrocytic TRPC6 protects against cerebral ischemia-reperfusion injury by inhibiting cGAS-STING pathway.

OBJECTIVE: Cerebral ischemia-reperfusion injury (CIRI) is complicated by BBB breakdown and neuroinflammation, processes partially regulated by astrocytes. This study aimed to investigate the neuroprotective mechanism of astrocyte-specific TRPC6, focusing on elucidating its molecular link to the cGAS-STING pathway and BBB integrity.

METHODS: MCAO mouse models were established, with astrocyte-specific TRPC6 overexpression achieved via stereotactic injection of AAV-GFAP-Trpc6. Neurological function, infarct volume, apoptosis, and BBB integrity (including tight junction proteins and AQP4) were systematically assessed. In vitro, OGD/R conditioned medium culture and co-culture were used for mechanistic validation, with the STING agonist ADU-S100 employed for intervention and causality confirmation.

RESULTS: Astrocyte TRPC6 overexpression significantly improved neurological function and behavioral outcomes, reduced infarct volume, and inhibited neuronal apoptosis. TRPC6 overexpression also stabilized the BBB, shown by reduced cerebral edema, reversed tight junction protein (ZO-1/Occludin) loss, and decreased AQP4 expression. Mechanistic analysis confirmed that TRPC6 overexpression significantly suppressed CIRI-induced activation of the astrocytic cGAS-STING pathway. The STING agonist ADU-S100 partially reversed the neuroprotective and BBB-stabilizing effects of TRPC6.

CONCLUSION: Astrocytic TRPC6 maintains BBB integrity by negatively regulating the cGAS-STING innate immune pathway in the early phase of CIRI. The study identified the "Astrocyte TRPC6-STING-Tight Junction" axis, offering a precise and promising novel therapeutic target for CIRI.