CHARACTERIZATION OF NEURONAL PROTEINS IN CIRCULATING EXTRACELLULAR VESICLES FROM LACUNAR STROKE PATIENTS

Abstract

Lacunar stroke accounts for 25% of ischemic stroke with a high risk for recurrence and cognitive impairment. Characterization of early response to stroke is vital for understanding lacunar stroke pathophysiology and new therapeutic interventions. Extracellular vesicles (EVs) are considered original sources for acquiring pathogenic information and identifying biomarkers, particularly for inaccessible tissues like the brain. EVs with the neuronal origin are circulating EVs, as blood EVs result from all tissues' contributions. Despite that, isolation and characterization of EVs continue to be a challenge. Besides, neuronal proteins in circulating EVs are not well characterized in patients with lacunar stroke. Thus, we aimed at optimizing immunocapture bead assay for selective exosome isolation from serum and characterize neuronal proteins in circulating EVs within 48 hours of lacunar stroke onset. CD63+ (from cell culture and serum), cell adhesion molecule L1+ (L1CAM+), and glutamine aspartate transporter+ (GLAST+) exosomes were isolated from serum using optimized immunocapture bead assay. L1CAM cytosolic fragment, Neural cell adhesion molecule (NCAM), β tubulin III, AMPA receptor (GluR2/3, and GluR2 subunits), GLAST, and VE-cadherin were enriched in both circulating exosomes and microparticle from patients with lacunar stroke. Also, a 300k filter can result in the loss of smaller size vesicles, affecting subsequent characterization. Although a larger cohort of samples is required, our preliminary data showed that AMPA receptor subunit GluR2/3, GLAST, and β tubulin III levels were significantly reduced in exosomes from patients with lacunar stroke compared to controls. Meanwhile, VE-cadherin and β tubulin III in circulating microparticles was significantly increased in lacunars stroke patients compared to control. The characterization of neuronal proteins in circulating EVs can improve brain-derived EVs' isolation tools, help identify potential biomarkers, and better manage lacunar stroke.

Date of Award	2021
Original language	American English
Awarding Institution	HBKU College of Health & Life Sciences