Exercise-induced extracellular vesicles derived from platelet-rich plasma improved recovery after ischemic stroke

Stroke remains a major global health burden, with limited treatments for chronic ischemic stroke necessitating novel therapies. This study explored the therapeutic potential of platelet-rich plasma (PRP)-derived extracellular vesicles (EVs) in stroke recovery, particularly in exercise-trained rats. PRP-derived EVs from treadmill-loaded and sedentary rats were designated athletes (aPRP-EVs) and non-athlete (nPRP-EVs), respectively. Both were administered to primary cortical neurons exposed to oxygen-glucose deprivation (OGD) and to adult male Wistar/ST rats subjected to permanent middle cerebral artery occlusion (MCAO). Exercise increased CD63, CD31, and transforming growth factor-β1 (TGF-β1) in PRP-derived EVs. In OGD-exposed neurons, aPRP-EVs enhanced viability, elevated phosphorylated neurofilament heavy chain, and reduced intracellular calcium. Canonical pathway analysis showed upregulated TGF-β/SMAD signaling in EV groups versus vehicle, while 'Ca signaling' was downregulated in aPRP-EVs versus nPRP-EVs. In MCAO rats, EVs improved neurological and motor function and reduced neuronal apoptosis at 28 days, with aPRP-EVs promoting earlier, greater recovery and infarct reduction. These effects correlated with TGF-β1 upregulation, SMAD4 nuclear translocation, reduced NMDAR2B expression, and enhanced axonal growth in the peri-infarct region. PRP-derived EVs, particularly from exercise-trained donors, enhance neuroregeneration and functional recovery in chronic ischemic stroke via TGF-β/SMAD and calcium signaling modulation.