目的:探讨核转录因子-κB(NF-κB)和缺氧诱导因子-1α(HIF-1α)两种蛋白及其mRNA在脑创伤后脑组织中表达的规律,为法医学损伤时间的推断提供依据。方法:雌性Wistar大鼠随机分为正常对照组和脑创伤组,分别于颅脑创伤后1、2、4、6、8、10、12、16、18h和24h处死,解剖取其脑组织。H-E染色观察大鼠脑组织病理学形态结构的变化,采用免疫组织化学SP法和PCR法分别检测上述两种蛋白和其mRNA在不同损伤时间组的表达及变化规律。结果:NF-κB蛋白的表达在损伤后1h开始升高,18h出现表达高峰期,18-24h出现平台期,损伤组除伤后1h和2h组外,其他各组NF-κB阳性表达均显著高于对照组,差异具有统计学意义;NF-κB mRNA于损伤后1h开始表达,6h达高峰,持续至24h,各损伤组NF-κB mRNA水平均显著高于对照组,差异具有统计学意义;HIF-1α伤后6h呈阳性表达,随着伤后时间的延长,表达逐渐增强,伤后24h表达最强,损伤组除伤后1、2、4h组外,其他各组HIF-1α阳性表达均显著高于对照组,差异具有统计学意义。HIF-1α mRNA于损伤后4h开始表达,18h达高峰,持续至24h,损伤组除1、2h组外,其他各组HIF-1α mRNA水平均显著高于对照组,差异具有统计学意义。结论:大鼠脑损伤后NF-κB和HIF-1α及其mRNA的表达均随损伤时间变化而变化,具有时序性变化规律,能够成为损伤时间推断的候选因子。
Objective: To study the expression features of nuclear factor (NF)-κB, hypoxia inducible factor (HIF)-1α, and their mRNA in brain trauma with different damage time and to provide evidence for forensic dating of wounds. Methods: A total of 66 female Wistar rats were equally and randomly divided into 11 groups, namely normal control group and 10 damage groups. Rats in the 10 damage groups were put to death in post-traumatic 1,2,4,6,8,10,12,16,18 and 24 hours. The brain tissue was taken out. Pathology morphological structure changes were observed by H-E staining. Expression of NF-κB and HIF-la and their mRNA were detected in different damage time using immunohistochemical SP method and PCR. Results: NF-κB expression rose in 1 hour after damage, reached the peak after 18 hours, from 18 to 24 hours in plateau. NF-κB positive expression in damage groups were significantly higher than that in control group except the 1 hour and 2 hour group. NF-κB mRNA level was significantly higher in darhage groups than that in control group. HIF-1α was expressed at 6 hours after damage, the expression was gradually strengthened, and the strongest expression was at 24 hours after damage. HIF-1α expression was significantly higher in all damage groups than the control group, in addition to the 1,2 and 4 hour group. HIF-1α mRNA was expressed 4 hours after injury and reached the peak at 18 h, maintained till 24 h. Except for the 1 h and 2 h injury groups, HIF-1α mRNA levels in the other groups were significantly higher than the control group, and the difference had statistical significance. Conclusion: The expression features of NF-κB, HIF-1α, and their mRNA changes with the damage time in brain trauma. The above factors may be used to speculate the forensic dating of wound.