TY - JOUR
T1 - P2X7 Receptor Suppression Preserves Blood-Brain Barrier through Inhibiting RhoA Activation after Experimental Intracerebral Hemorrhage in Rats
AU - Zhao, Hengli
AU - Zhang, Xuan
AU - Dai, Zhiqiang
AU - Feng, Yang
AU - Li, Qiang
AU - Zhang, John H.
AU - Liu, Xin
AU - Chen, Yujie
AU - Feng, Hua
N1 - Funding Information:
This study was supported by the National Basic Research Program of China (973 Program, No. 2014CB541600) and the National Natural Science Foundation of China (Grant No. 81501002, 81220108009).
PY - 2016/3/16
Y1 - 2016/3/16
N2 - Blockading P2X7 receptor(P2X7R) provides neuroprotection toward various neurological disorders, including stroke, traumatic brain injury, and subarachnoid hemorrhage. However, whether and how P2X7 receptor suppression protects blood-brain barrier(BBB) after intracerebral hemorrhage(ICH) remains unexplored. In present study, intrastriatal autologous-blood injection was used to mimic ICH in rats. Selective P2X7R inhibitor A438079, P2X7R agonist BzATP, and P2X7R siRNA were administrated to evaluate the effects of P2X7R suppression. Selective RhoA inhibitor C3 transferase was administered to clarify the involvement of RhoA. Post-assessments, including neurological deficits, Fluoro-Jade C staining, brain edema, Evans blue extravasation and fluorescence, western blot, RhoA activity assay and immunohistochemistry were performed. Then the key results were verified in collagenase induced ICH model. We found that endogenous P2X7R increased at 3 hrs after ICH with peak at 24 hrs, then returned to normal at 72 hrs after ICH. Enhanced immunoreactivity was observed on the neurovascular structure around hematoma at 24 hrs after ICH, along with perivascular astrocytes and endothelial cells. Both A438079 and P2X7R siRNA alleviated neurological deficits, brain edema, and BBB disruption after ICH, in association with RhoA activation and down-regulated endothelial junction proteins. However, BzATP abolished those effects. In addition, C3 transferase reduced brain injury and increased endothelial junction proteins' expression after ICH. These data indicated P2X7R suppression could preserve BBB integrity after ICH through inhibiting RhoA activation.
AB - Blockading P2X7 receptor(P2X7R) provides neuroprotection toward various neurological disorders, including stroke, traumatic brain injury, and subarachnoid hemorrhage. However, whether and how P2X7 receptor suppression protects blood-brain barrier(BBB) after intracerebral hemorrhage(ICH) remains unexplored. In present study, intrastriatal autologous-blood injection was used to mimic ICH in rats. Selective P2X7R inhibitor A438079, P2X7R agonist BzATP, and P2X7R siRNA were administrated to evaluate the effects of P2X7R suppression. Selective RhoA inhibitor C3 transferase was administered to clarify the involvement of RhoA. Post-assessments, including neurological deficits, Fluoro-Jade C staining, brain edema, Evans blue extravasation and fluorescence, western blot, RhoA activity assay and immunohistochemistry were performed. Then the key results were verified in collagenase induced ICH model. We found that endogenous P2X7R increased at 3 hrs after ICH with peak at 24 hrs, then returned to normal at 72 hrs after ICH. Enhanced immunoreactivity was observed on the neurovascular structure around hematoma at 24 hrs after ICH, along with perivascular astrocytes and endothelial cells. Both A438079 and P2X7R siRNA alleviated neurological deficits, brain edema, and BBB disruption after ICH, in association with RhoA activation and down-regulated endothelial junction proteins. However, BzATP abolished those effects. In addition, C3 transferase reduced brain injury and increased endothelial junction proteins' expression after ICH. These data indicated P2X7R suppression could preserve BBB integrity after ICH through inhibiting RhoA activation.
KW - Occludin/metabolism
KW - Gene Expression
KW - Receptors, Purinergic P2X7/genetics
KW - Tetrazoles/pharmacology
KW - Antigens, CD/metabolism
KW - RNA, Small Interfering/genetics
KW - Male
KW - Rats, Sprague-Dawley
KW - Brain/blood supply
KW - Gene Knockdown Techniques
KW - Adenosine Triphosphate/analogs & derivatives
KW - Animals
KW - Zonula Occludens-1 Protein/metabolism
KW - RNA Interference
KW - rhoA GTP-Binding Protein/metabolism
KW - Blood-Brain Barrier/drug effects
KW - Cadherins/metabolism
KW - Cerebral Hemorrhage/drug therapy
KW - Purinergic P2X Receptor Antagonists/pharmacology
KW - Enzyme Activation
KW - Pyridines/pharmacology
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UR - http://www.scopus.com/inward/citedby.url?scp=84961840150&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/8d9dc97f-f9ff-3356-9ca6-f79fbb343523/
U2 - 10.1038/srep23286
DO - 10.1038/srep23286
M3 - Article
C2 - 26980524
SN - 2045-2322
VL - 6
JO - Scientific Reports
JF - Scientific Reports
M1 - 23286
ER -