Astrocyte Dysfunction Reflected in Ischemia-Induced Astrocyte-Derived Extracellular Vesicles: A Pilot Study on Acute Ischemic Stroke Patients

Extracellular vesicles (EVs) secreted by astrocytes (ADEVs) mediate numerous biological processes, providing insights into damage, repair, and protection following ischemic stroke (IS). This pilot study aimed to broaden the current knowledge on the astrocyte response to ischemia by dynamically assessing the aquaporin-4 (AQP4) and glial cell line-derived neurotrophic factor (GDNF) as cargo proteins of these vesicles in eighteen acute IS patients and nine controls. EV proteins were detected by Western blotting and followed 24 h (D1), 7 days (D7), and one month (M1) after symptoms onset. The post-ischemic ADEV AQP4 and GDNF levels were higher at D1 compared to the control group (<i>p</i> = 0.006 and <i>p</i> = 0.023). Significant differences were observed in ADEV AQP4 during the three evaluated time points (n = 12, <i>p</i> = 0.013) and between D1 and D7 (z = 2.858, <i>p</i> = 0.012), but not in EV GDNF. There was a positive relationship between the severity of stroke at D1 according to the National Institutes of Health Stroke Scale, and ADEV AQP4 at D1 (r = 0.50, <i>p</i> = 0.031), as well as ADEV GDNF at D1 and D7 (r = 0.49, <i>p</i> = 0.035 and r = 0.53, <i>p</i> = 0.021, respectively). The release of EVs with distinct protein profiles can be an attractive platform for the development of biomarkers in IS.