Inhibition of the immunoproteasome LMP_(2) ameliorates ischemia/hypoxia-induced blood–brain barrier injury through the Wnt/β-catenin signalling pathway  

作　　者：Xing-Yong Chen Shao-Fen Wan Nan-Nan Yao Ze-Jing Lin Yan-Guang Mao Xiao-Hua Yu Yin-Zhou Wang 

机构地区：[1]Department of Neurology,Fujian Provincial Hospital,Shengli Clinical Medical College of Fujian Medical University,No.134,Dongjie,Gulou District,Fuzhou 350001,China [2]Fujian Academy of Medical Science,Fuzhou 350o01,China [3]Key Testing Laboratory of Fujian Province,Fuzhou 350001,China.

出　　处：《Military Medical Research》2022年第4期404-418,共15页军事医学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(81771250);the Natural Science Foundation of Fujian Province,China(2020J011059,2020R1011004);the Joint Funds for the Innovation of Science and Technology of Fujian Province,China(2017Y9065);the High-level hospital foster grants from Fujian Provincial Hospital,Fujian Province,China(2020HSJJ07)。

摘　　要：Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2(LMP2)in the pathophysiology of ischemia stroke.However,the relationship between the immunoproteasome LMP2 and the BBB remains unclear.Methods:Adult male Sprague–Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion(MCAO/R).Three days before MCAO,the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region.The rat brain microvascular endothelial cell(RBMVEC)line was exposed to oxygen–glucose deprivation/reperfusion(OGD/R)to mimic ischemic conditions in vitro.The RNA interference-mediated knockdown of LMP2 orβ-catenin was analysed in vivo and in vitro.Analysis of the quantity of extravasated Evans blue(EB)and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB.Immunofluorescence and Western blotting were employed to detect the expression of target proteins.Cell migration was evaluated using a scratch migration assay.The results of immunofluorescence,Western blotting and cell migration were quantified using the software ImageJ(Version 1.53).Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference(LSD)test.Results:Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins[occludin,claudin-1 and zonula occludens(ZO-1)]in the MCAO/R group compared with the sham group(P<0.001).However,inhibition of the immunoproteasome LMP2 restored the expression of these proteins,resulting in higher levels of occludin,claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group(P<0.001).In addition,inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability[e.g.,the quantity of extravasate

关 键 词：IMMUNOPROTEASOME Blood–brain barrier Wnt/β-catenin pathway Oxygen–glucose deprivation/reperfusion Cerebral ischemia 

分 类 号：R392[医药卫生—免疫学]