HSPB8 over-expression prevents disruption of blood-brain barrier by promoting autophagic flux after cerebral ischemia/reperfusion injury
HSPB8 over-expression prevents disruption of blood-brain barrier by promoting autophagic flux after cerebral ischemia/reperfusion injury
复制标题
HSPB8过表达通过促进脑缺血/再灌注损伤后的自噬通量来防止血脑屏障的破坏
DOI：
10.1111/jnc.14626
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发表时间：
2019-01-01
影响因子：
4.7
通讯作者：
Hu, Zhiping
中科院分区：
文献类型：
--
作者：
Li, Fazhao;Yang, Binbin;Hu, Zhiping
最近有报道称，热休克蛋白 B8 (HSPB8) 可在体内和体外针对缺血/再灌注 (I/R) 诱导的脑损伤提供神经保护作用。然而，其分子机制仍不清楚。本研究重点关注脑室内 (i.c.v) 递送 lenti-HSPB8 病毒对脑 I/R 大鼠模型神经损伤的影响，并探讨其潜在机制。我们发现，在大鼠大脑中动脉闭塞/再灌注（MCAO/R）模型中，慢病毒静脉注射诱导的 HSPB8 过度表达可显着减轻梗塞体积，改善神经行为结果，并减少脑水肿。与此同时，与媒介物组相比，HSPB8 过表达显着防止脑 I/R 损伤后血脑屏障 (BBB) 破坏，同侧半球伊文思蓝渗漏和 IgG 检测减少表明。此外，紧密连接蛋白claudin-5和occludin的免疫印迹和免疫荧光染色显示，HSPB8的过表达阻止了MCAO/R诱导的这些蛋白的降解，这表明HSPB8对BBB具有保护作用。还利用蛋白质印迹和免疫染色技术来分析自噬标记物的表达。我们发现 HSPB8 过表达促进了自噬流，LC3 I/II 比例增加、Beclin-1 表达积累和 p62 降解增强证明了这一点。再灌注开始时，静脉注射15g自噬抑制剂3-甲基腺嘌呤（3-MA）。结果显示，3-MA 导致 HSPB8 对 MCAO/R 诱导的神经缺陷、伊文思蓝外渗和紧密连接蛋白损失的保护作用显着丧失，表明 HSPB8 的 BBB 保护作用至少部分是通过自噬介导的。总的来说，HSPB8 可能是一种在脑 I/R 损伤后保持 BBB 完整性的潜在治疗剂。
Heat-shock protein B8 (HSPB8) has been recently reported to confer neuroprotection against ischemia/reperfusion (I/R)-induced cerebral injury invivo and invitro. However, the molecular mechanism is still elusive. This study focused on the effect of intracerebroventricular (i.c.v) delivery of lenti-HSPB8 virus against neurological injury in a rat model of cerebral I/R and explored the underlying mechanism. We found that lentivirus i.c.v injection-induced HSPB8 over-expression strongly alleviated infarct volume, improved neurobehavioral outcomes, and reduced brain edema in rat middle cerebral artery occlusion/reperfusion (MCAO/R) model. Concomitantly, HSPB8 over-expression noticeably prevented blood-brain barrier (BBB) disruption after cerebral I/R injury as indicated by the reduction in Evans blue leakage and IgG detection in the ipsilateral hemisphere compared with the vehicle group. Moreover, immunoblotting and immunofluorescence staining of tight junction proteins claudin-5 and occludin showed that HSPB8 over-expression prevented the degradation of these proteins induced by MCAO/R, which indicated the protective effect of HSPB8 on BBB. Western blotting and immunostaining techniques were also utilized to analyze the expression of the markers of autophagy. We found that HSPB8 over-expression promoted autophagic flux, evidenced by increased ratio of LC3 I/II, accumulation of Beclin-1 expression and enhanced p62 degradation. i.c.v injection of 15g autophagy inhibitor 3-methyladenine (3-MA) was applied at the onset of reperfusion. The results showed that 3-MA elicited a significant loss of the protective effect of HSPB8 against MCAO/R-induced neurological defect, Evans blue extravasation, and the loss tight junction proteins, suggesting that the BBB protective role of HSPB8 was, at least in part, mediated through autophagy. Collectively, HSPB8 may represent a potential therapeutic agent for preserving BBB integrity following cerebral I/R injury.