Abstract

Protective Effects of Preactivated and Disaggregated Shape-Changed Platelets and Human Embryonic Stem Cell-Derived Exosomes Improve Neurological Function and Attenuate Brain Infarct after Acute Ischemic Stroke

Author(s): Yi-Ling Chen, Yuan-Ping Lin, Sung Pei-Hsun, Pei-Lin Shao, Hon-Kan Yip, Sarah Chua

Abstract

Background: This investigation tested the hypothesis that preactivated and disaggregated shape-changed platelets (PreD-SCP) and human embryonic stem cell-derived exosomes (hESC-Exo) treatments can reduce brain-infarct area (BIA) in rat with preservation of neurological function following acute ischemic stroke (AIS) induced by left middle-cerebral artery occlusion.

Materials and Methods: Adult-male Sprague-Dawley rats (n=24) were randomly divided into group 1 (sham-control), 2 (AIS), 3 [AIS + PreD-SCP (3.0x108 cells)] and 4 (AIS + hESC-Exo, 100 μg). PreD-SCP and hESC-Exo were administered intravenously at 2/6/24 hours after the AIS procedure for animals in group 3 and 4, respectively. All animals were euthanized by day-28 post-AIS.

Results: Brain infarct area (BIA) measured by histopathology was significantly larger in group 2 than that in other groups, and significantly larger in group 3 and 4 than that in group 1 (p<0.01), but it showed no difference between group 3 and 4. The improvement in neurological function displayed a pattern opposite to that of BIA by days 3/7/14/28 after AIS in the four groups (all p<0.01). The protein expressions of inflammation (MMP-9/TNF-α/Cox-2/iNOS), oxidative stress (oxidized protein/NOX-1/NOX-2) and apoptosis (cleaved-caspase-3/PARP/mitochondrial-Bax) exhibited a pattern identical to that of BIA among the four groups (all p<0.01). The cellular levels of inflammatory (CD14+/CD68+/GFAP+), DNA-damage/apoptotic (γ-H2AX+/apoptotic nuclei) biomarkers exhibited an identical pattern, whereas the neuron/myelin-sheath integrity markers (NeuN+/BMP+ cells) expressed an opposite pattern compared to that of BIA in the four groups (all p<0.05). The expressions of endothelial cell markers at cellular (CD31+/vWF+) and protein (CD31/eNOS/vWF) levels and the number of small vessels showed an opposite pattern compared to that of BIA in all groups, whereas the endothelial progenitor cell markers at cellular/protein (CXCR4/SDF-1α) levels progressively increased from groups 1 to 4 (all p<0.001).

Conclusion: PreD-SCP and hESC-Exo treatments significantly protected the brain from AIS damage andimproved neurological outcome.