Abstract TP031: Migrasomes from Astrocytes Facilitate Post-Stroke Repair: Targeting the Neurovascular Unit

Background: Ischemic stroke leads to substantial disruption of the neurovascular unit (NVU), compromising neuronal viability and vascular integrity. Migrasomes, a novel class of extracellular vesicles formed during cell migration, have emerged as key mediators of intercellular signaling under stress. This study investigates how ischemia-like conditions affect the generation and function of astrocyte-derived migrasomes, and explores their roles in NVU remodeling and neurological recovery following ischemic stroke. Methods: Primary astrocytes were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to mimic ischemic injury. Migrasome formation was analyzed via fluorescence labeling, confocal and electron microscopy, and Western blotting. Proteomic profiling characterized stress-induced changes in migrasome cargo. In vitro co-culture assays evaluated migrasome effects on neurons, endothelial cells (ECs), and blood-brain barrier (BBB) integrity. EC transcriptomic changes were assessed via RNA-seq. In vivo efficacy was tested in a mouse middle cerebral artery occlusion (MCAO) model with delayed (24h) administration of exogenous migrasomes and subsequent neurological and histological evaluations. Results: OGD/R markedly increased migrasome production in astrocytes and induced proteomic shifts involving oxidative phosphorylation, endocytosis, and cytoskeletal remodeling. Migrasomes from healthy astrocytes (MCtrl) enhanced neuronal viability, promoted synaptic protein expression (synaptophysin, PSD95), and preserved BBB integrity via upregulation of tight junction proteins (ZO1, CD31). In contrast, ischemia-conditioned migrasomes (MOGD/R) aggravated synaptic damage and endothelial barrier disruption. RNA-seq of ECs exposed to MCtrl revealed upregulation of ferroptosis-suppressing genes including Txn and Txnrd1, suggesting antioxidant-mediated protection. In vivo, MCtrl treatment significantly improved motor and sensory function, reduced infarct volume, and preserved NVU architecture, while MOGD/R had minimal benefit or detrimental effects. Conclusion: Astrocyte-derived migrasomes exert context-dependent effects on NVU recovery after stroke. Migrasomes from non-injured astrocytes promote neuroprotection, suppress endothelial ferroptosis, and restore BBB integrity, supporting their development as a novel cell-free therapeutic strategy for stroke recovery.