亚低温对颅脑创伤后受体相互作用蛋白激酶-1表达影响的实验研究

Effect of mild hypothermia treatment on rat RIPK - 1 expression following traumatic brain injury

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.