人脑挫裂伤早期周围组织AQP4表达及血脑屏障超微结构观察

The expression of aquaporin-4 and the ultramicrostructure change of blood-brain barrier in human contusion brain tissue early after injury

摘要:

目的 观察人脑挫裂伤后AQP4和血脑屏障超微结构在脑水肿形成中不同时间点的变化特征，探讨脑水肿的形成机制。方法 取脑挫裂伤区组织标本60例（观察组），10例非功能区正常脑组织标本（对照组）。采用免疫组化和图像分析技术测定正常组及观察组伤后2~72 h相应时间点水肿区AQP4的表达水平，同时观察脑水肿含水量，血脑屏障指数，血脑屏障超微结构的变化。结果 与正常组相比较，脑挫裂伤组在伤后2 h后AQP4表达开始增加（P<0.05），6 h、8 h、12 h明显增加（P<0.01），24~72 h达到最高（P<0.01）。AQP4表达与脑含水量的变化趋于一致（r=0.912，P<0.01）；血脑屏障（BBB）指数与脑含水量的变化趋于一致（r=0.877，P<0.01）；水通道蛋白4表达与BBB指数呈显著正相关（r=0.908，P<0.01）。伤后早期血脑屏障结构即发生改变，随后血脑屏障结构被明显破坏，24 h、 72 h血脑屏障破坏最为严重。结论 脑挫裂伤后AQP4表达明显增强，BBB的通透性增加，提示AQP4在损伤后脑水肿的形成过程中起重要作用。

Abstract:

Objective To observe the expression of aquaporin 4(AQP4) and the ultramicrostructure change of blood-brain barrier in human contusion brain tissue at different time points and investigate the mechanism of brain edema formation. Methods 60 cases brain contusion tissue (observation group) and 10 cases normal non-functional brain tissues (control group) were collected. The expression of AQP4 at different time point was detected by immunity histochemistry and image analytical technique at 2~72 h after injury,brain water contents, BBB index and ultramicrostructure were observed at the same time point. Results Compared with the normal control group, AQP4 expression increased in observation group at 2 h (P<0.05), obviously increased at 6 h、8 h、12 h (P<0.01), reached peak at 24~72 h(P<0.01). The change of AQP4 expression and brain water content had same tendency(r=0.912,P<0.01) which also was displayed between BBB index and brain water content(r=0.877,P<0.01). The change of AQP4 expression and BBB index had significant positive correlation(r=0.908,P<0.01). Blood-brain barrier structure changed early after injury, and then destroyed, severely damaged at 24 h, 72 h. Conclusions The expression of AQP4 and the permeability of BBB significantly increased after brain contusion which suggesting AQP4 may play an important role in the brain edema formation after brain contusion.