人脑挫裂伤早期HMGB1的表达变化特征

The features of HMGB1 expression in early traumatic brain injury

目的探讨人脑挫裂伤早期HMGB1表达的变化特征。方法收集人脑挫裂伤后不同时间点挫裂伤组织的标本(正常组、6h、12h、24h、72h),4%多聚甲醛固定,冰冻切片,然后进行免疫荧光染色,统计分析各时间点HMGB1的表达情况;同时将HMGB1与神经元标志物NeuN进行共标,观察人脑挫裂伤后早期神经元损伤过程中从核内向胞浆内转移的情况。结果正常人脑组织的HMGB1表达主要集中在细胞核内,与正常组相比较,人脑挫裂伤组在伤后HMGB1阳性细胞数于12h开始下降(P<0.05),并持续至72h;而HMGB1从核内转移至胞浆内的数目从6h即开始增加(P<0.05),随时间增加HMGB1也随之大量转移到胞浆中,在人脑挫裂伤后24h达到高峰(P<0.05)。人脑挫裂伤后早期,HMGB1主要表达在神经元中(P>0.05),脑挫裂伤后神经元的数目逐渐减少(P<0.05),而HMGB1从神经元核内转移至胞浆的比例在6h明显增加(P<0.05),于24~72h达到高峰(P<0.05)。结论人脑挫裂伤后早期神经元死亡或凋亡数目明显增加,HMGB1阳性细胞数也在损伤后减少;而HMGB1神经元从核内转移至胞浆的比例升高;HMGB1可能参与了脑挫裂伤后神经元的死亡或凋亡。

Objective To explore the features of high-mobility group box l（HMGB1）expression in early traumatic brain injury（TBI）. Methods We collected traumatic brain tissues induced by traumatic brain injury at different time point（6 h,6 h,12 h,24 h and 72 h）and normal brain tissues which were fixed by 4G paraformaldehyde. After performing frozen section and using immunofluorescent staining, we statistically analyzed the expression of HMGB1. At the same time, we observed the transferring situation from cell nucleus to cytoplasm in the process of early traumatic brain injury by marking HMGB1 and neuronal specific marker（NeuN）. Results HMGB1 expression of normal brain tissues was concentrated in nucleus. The number of HMGB1 positive cells in traumatic brain tissues was decreased at 12 h（P〈0.05） ,which lasted to 72 h. The number of HMGB1 transferring from cell nucleus to cytoplasm was increased at 6 h （P〈0.05 ） and reach the peak at 24 h after traumatic brain injury （P 〈0.05）, which showed that with the prolonged time, the more number of HMGB1 transferred to cytoplasm. In early traumatic brain injury, HMGB1 mainly expressed in neurons（P〉0.05）which were decreased gradually（P〈0.05）. We also found the number of HMGB1 transferring from nucleus to cytoplasm was significantly increased at 6 h （P 〈0.05 ）, and peaked at 24 - 72 h （P 〈0.05 ）. Conclusion The number of neurons＇ death or apoptosis was decreased after TBI in human,and number of HMGB1 positive cells was also decreased. The ratio of HMGB1 transferring from nucleus into cytoplasm was significantly increased. HMGB1 may participate in the neurons＇ death or apoptosis.