PLC及IP_3R拮抗剂对弥漫性轴索损伤后继发性脑损伤的治疗作用  

Therapeutic effects of inhibitors of PLC and IP3R on secondary brain injury after diffuse axonal injury

作　　者：李宇[1] 宋锦宁[1] 张明[1] 安吉洋[1] 孙鹏[1] 李丹东[1] 马旭东[1] 赵雅慧[1] 

机构地区：[1]西安交通大学医学院第一附属医院神经外科,陕西西安710061

出　　处：《西安交通大学学报（医学版）》2015年第1期28-33,共6页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：国家自然科学基金资助项目(No.30471774);教育部新世纪优秀人才支持计划资助项目(No.NCET-05-0831);陕西省自然科学基金资助项目(No.2003C1-16)~~

摘　　要：目的研究弥漫性轴索损伤(diffuse axonal injury,DAI)后PLC及IP3R抑制剂对DAI引发的脑水肿及神经元变性、损伤程度的影响,阐明PLC及IP3R抑制剂对DAI后继发性损伤的治疗作用。方法采用头颅冠状面瞬间加速旋转装置,制作大鼠颅脑DAI模型,并使用侧脑室穿刺给药的方法注射PLC抑制剂U73122及IP3R抑制剂光溜海绵素C(Xestospongin,XeC)。采用干湿重法测量脑组织含水量,ELISA测量脑脊液及动脉血中血清白蛋白(Alb)浓度并计算比值(QAlb),免疫组化法测量β-淀粉样前体蛋白(β-APP)的阳性面积及Western blot方法测量PLC的磷酸化程度。结果 DAI后6h大鼠脑组织含水量已明显增加,24h到达顶点,之后逐步下降,在5d时恢复到损伤前水平,XeC及U73122干预明显降低了损伤后24h脑组织含水量。ELISA结果显示DAI后6h及24h脑脊液中Alb浓度及QAlb明显升高,之后下降至损伤前水平,XeC及U73122干预对DAI引起的脑脊液中Alb浓度及QAlb升高无明显影响。免疫组化结果显示DAI后24h的β-APP的阳性面积较损伤前明显升高,XeC及U73122干预显著降低了DAI后24h的β-APP阳性面积。结论 DAI后脑水肿的形成是由细胞毒性水肿及血管源性水肿共同构成的;PLC及IP3R抑制剂降低了DAI后的细胞毒性水肿及神经元变性、损伤程度,对DAI后的继发性脑损伤具有治疗作用。Objective To investigate whether inhibitors of PLC and IPa R have therapeutic effects on neuronal degeneration and damage caused by diffuse axonal injury （DAI）. Methods In vivo DAI model was established by an instant lateral head rotation device. And intracerebroventricular injection method was used for the drug administration of xestospongin C （XeC, inhibitor of IP3 receptor） and U73122 （inhibitor of PLC）. Then, wet-dry weight ratio method was used to measure brain water content. ELISA was conducted to measure albumin （Alb） concentrations both in the spinal cerebral fluid （CSF） and serum, and ratio of Alb concentration in CSF to Alb concentration in the serum （QAIb） was calculated. β-APP immunohistochemistry was used to determine the degree of neuronal degeneration and injury. Western blot was applied to test whether U73122 intracerebroventricular injection suppressed the phosphorylation process of PLC. Results The brain water content increased significantly at 6 h after DAI, pcaked at 24 h, then gradually declined, and resumed its pre-DAl level at 5 d. XeC and U73122 treatments significantly reduced DAl-triggered increase of brain water content at 24 h after DAI. Results of ELISA showed that the concentration of Alb in CSF and Qalb significantly increased at 6 h and 24 h after DAI and then declined to its pre-DA! level. However, neither XeC nor U73122 treatment significantly suppressed this increase. lmmunohistochemistry showed that the β-APP positive area significantly increased at 24 h after DAI, and this increase could be significantly reduced by administration of either XeC or U73122. Conclusion Brain edema formation, triggered by DAI, consists of both cytotoxic edema and vasogenic edema. Both Xe C and U73122 treatments significantly attenuate cytotoxic edema formation and reduce neuronal damage after DAI. More importantly, PLC-IP3 signaling pathway may play an important role in the secondary damage process after DA1.

关 键 词：颅脑损伤 弥漫性轴索损伤 PLC IP3 β-淀粉样前体蛋白(β-APP) 

分 类 号：R651.15[医药卫生—外科学]