目的探讨亚低温对颅脑创伤(TBI)后大鼠脑组织受体相互作用蛋白激酶-1(RIPK-1)表达的影响。方法成年雄性7周龄Wistar大鼠40只,按随机数字表顺序分为5组:正常组(Normal)、假手术组(Sham)、假手术联合亚低温组(Sham+HT)、颅脑创伤常温组(TBI,37~C)、颅脑创伤亚低温组(TBI+HT,32℃),每组8只。建立液压打击致TBI模型后即可采用亚低温干预持续6h。采用神经功能缺损评分(NSS)观察TBI前后行为改变。伤后48h处死大鼠并取脑组织行HE染色,分别采用RT—PCR、real—timePCR和免疫印迹(Western—blot)法检测RIPK-1在基因和蛋白水平的表达,并用免疫组化法检测其在细胞水平的定位。结果与TBI组比较,TBI+HT组NSS评分明显降低(P〈0.01)。TBI组中RIPK-1的基因和蛋白表达明显高于Sham组(P〈0.05),而TBI+HT组RIPK-1表达较TBI组显著降低(P〈0.05)。RIPK-1蛋白在神经元和胶质细胞均有表达,而且TBI+HT组RIPK-1表达显著降低(P〈0.05)。结论亚低温可能通过抑制RIPK-1诱导的细胞坏死性凋亡通路来发挥神经保护作用,这为TBI的新靶向治疗提供了实验依据。
Objective To investigate the correlationbetween mild hypothermia treatment and gene transcription and protein expression of receptor - interacting protein kinase - 1 (RIPK - 1 ) following by traumatic brain injury (TBI) in rats. Methods Forty adult male Wistar rats were randomly divided into 5 equal groups (normal, sham, sham + hypothermia, TBI, and TBI + hypothermia). After TBI induced by fluid percussion injury (FPI), group TBI remained at normal temperature (37~C), and group ( TBI + hypothermia) underwent mild hypothermia (32~C) for4 k Neurological severity scores (NSS) were then assessed. All rats were sacrificed at 48 h and brain tissues were harvested, stained with hematoxylin and eosin (HE). mRNA and protein expressions of RIPK - 1 were analyzed by reverse transcription - polymerase chain reaction ( RT - PCR), real - time PCR, Western - blot, and immunohistochemistry (IHC), respectively. Results Significantly decreased NSS scores were observed in group TBI + hypothermia compared to group TBI ( P 〈 0. O1 ). Additionally, group TBI increased RIPK - 1 levels compared to group sham ( P 〈 0. 05 ). Reduced expression of RIPK - 1 were apparent in group TBI + hypothermia compare to group TBI ( P 〈 0. 05). However, no statistically significant difference was observed among groups normal, sham, and sham + hypothermia in NSS scores and the expression of RIPK - 1 ( P 〉 0. 05) . Conclusion Mild hypothermia treatment significantly reduced NSS score and RIPK - 1 upregulation after TBI, which may provide a better understanding of the mechanisms by which hypothermia reduces secondary brain injury in TBI patients.