Aquaporin-4-overexpressing mesenchymal stem cells promote neurological recovery after intracerebral hemorrhage by inhibiting TLR4/NF-κB signaling.

Intracerebral hemorrhage (ICH), a condition characterized by non-traumatic bleeding in the brain parenchyma, leads to acute neurological deficits through direct tissue injury and neuroinflammation, yet effective therapeutic strategies remain limited. Here, we investigated the potential of aquaporin-4-modified mesenchymal stem cells (AQP4-MSCs) as an immunotherapeutic approach for ICH. Using a collagenase IV-induced ICH mouse model, we demonstrated that transplantation of AQP4-MSCs significantly reduced cerebral edema and blood-brain barrier disruption, improved neurological function, and stabilized astrocyte morphology and glymphatic system activity. Furthermore, AQP4-MSCs enhanced glymphatic transport and waste clearance while decreasing inflammatory cytokine secretion and increasing glial cell line-derived neurotrophic factor release. Mechanistically, AQP4 was found to bind directly to TLR4 on glial cells, blocking sustained inflammatory stimulation and inhibiting downstream NF-κB pathway phosphorylation, thereby attenuating neuroinflammatory amplification and neuronal injury. Collectively, these findings reveal that AQP4-MSCs restore glymphatic function and mitigate inflammatory cascades post-ICH through TLR4/NF-κB suppression, offering a novel therapeutic strategy for hemorrhagic stroke.