MMP-9 inhibition alleviates postoperative cognitive dysfunction by improving glymphatic function via regulating AQP4 polarity

Postoperative cognitive dysfunction (POCD) is a common complication after surgery, characterized by deficits in memory, attention and cognitive flexibility. However, the underlying mechanisms of POCD remain unclear. Neuroinflammation and blood–brain barrier disruption have been implicated as potential pathological processes. This study explores the neuroprotective effects and mechanisms of the matrix metalloproteinase(MMP-9)inhibitor GM6001 against POCD. We hypothesize GM6001 may reduce neuroinflammation and preserve blood–brain barrier integrity through direct inhibition of MMP-9. Moreover, GM6001 may stabilize aquaporin-4 polarity and glymphatic clearance function by modulating MMP-9-mediated cleavage of dystroglycan, a key protein for aquaporin-4 anchoring. Our results demonstrate GM6001 alleviates postoperative cognitive deficits and neuroinflammation. GM6001 also preserves blood–brain barrier integrity and rescues aquaporin-4 mislocalization after surgery. This study reveals a novel dual role for MMP-9 inhibition in cognitive protection through direct anti-neuroinflammatory effects and regulating aquaporin-4 membrane distribution. Targeting MMP-9 may represent a promising strategy to prevent postoperative cognitive dysfunction by integrating multiple protective mechanisms.