高压氧治疗对创伤性脑损伤大鼠的神经功能及CyclinD1表达的影响

Effects of hyperbaric oxygen treatment on neurological functional and expression of CyclinD1 in rats with traumatic brain injury

目的研究高压氧治疗对创伤性脑损伤大鼠的神经功能及细胞周期蛋白D1(Cyclin D1)表达的影响。方法用随机数字表法将24只成年Sprague Dawley大鼠随机分为假手术组、脑创伤组及高压氧治疗组,每组8只。采用自由落体打击法制作中度脑创伤大鼠模型,高压氧治疗组大鼠在脑创伤后给予高压氧治疗,每天1次,连续10 d;假手术组大鼠仅行开颅而不致脑损伤。在伤后第1 d、5 d、10 d对各组大鼠进行神经功能缺损(NSS)评分。在伤后第10 d将大鼠处死,取右侧大脑损伤皮质区组织;采用免疫组织化学法检测Cyclin D1蛋白的表达水平,逆转录聚合酶链式反应(rt-PCR)检测Cyclin D1 mRNA的表达水平。结果脑创伤组大鼠伤后各时间点的NSS评分均明显高于假手术组(均P<0.01),而高压氧治疗组大鼠伤后第5 d、10 d的NSS评分明显低于脑创伤组(均P<0.05)。免疫组化染色检测显示,Cyclin D1阳性染色产物主要分布于胶质细胞和神经元的胞核。与假手术组比较,脑创伤组的Cyclin D1阳性细胞数明显增多(P<0.01);而高压氧治疗组的阳性细胞数比脑创伤组明显减少(P<0.01),但仍高于假手术组。脑创伤组的Cyclin D1阳性染色相对光密度值与假手术组比较明显升高,而高压氧治疗组的相对光密度值与脑创伤组比较则明显降低,差异均有统计学意义(均P<0.01)。脑创伤组的Cyclin D1 mRNA表达水平与假手术组比较明显升高,而高压氧治疗组的Cyclin D1 mRNA表达水平则明显低于脑创伤组,差异均有统计学意义(均P<0.01)。结论高压氧治疗能显著促进创伤性脑损伤大鼠的神经功能恢复,并抑制了Cyclin D1的表达。

Objective To investigate the effects of hyperbaric oxygen treatment（ HBOT） in rats with traumatic brain injury（ TBI） associated to the neurological function improvement and the expression of Cyclin D1. Methods According to the random number table,24 adult Sprague Dawley rats were randomly divided into three groups（ 8 rats each group） ： sham-operated group,TBI group and HBOT group. The TBI group was subjected to TBI procedure according to the method,the 50 g weight-drop device employed and fallen from 40 cm height to define the severity of the injury; the sham-operated group was subjected to skull open only but not brain injury. The HBOT group was performed for HBO treatment for 10 days（ one time every day） after TBI. The neurological severity scores（ NSS） records were evaluated after 1,5,10 days post injury. Then all rats were sacrificed and the injury cortex was obtained for the following immunohisto-chemical staining and reverse transcription-polymerase chain reaction（ rt-PCR） of Cyclin D1. Results Comparing to the shame group,the NSS score records in the TBI group were significantly increased,while HBOT group showed a significant decrease comparing to the TBI rats. Meanwhile,the expressions of protein and mRNA for Cyclin D1 in the TBI group were significantly up-regulated compared with the shamed one,while HBOT group was significantly down-regulated compared with TBI rats. Conclusion The HBO treatment ameliorates the neurological function of the rats and inhibits the expression of Cyclin D1 after experimental traumatic brain injury.