目的

探讨缺氧预处理(HPC)对创伤性脑损伤(TBI)大鼠挫伤灶周围皮层组织中缺氧诱导因子-1α(HIF-1α)、葡萄糖转运体3型(GLUT-3)表达及神经元存活影响。

方法

120只Sprague-Dawley 大鼠按随机数字法分为对照组(12 只)、TBI 组(54 只)、HPCT 组(54 只)。TBI 组按Feeney 自由落体撞击法建立大鼠TBI 模型，HPCT 组先给予3 d HPC(50.47 kPa，3 d，3 h/d)，之后同法致伤。采用RT-PCR及Western blotting检测伤后1、4、8、12 h及1、3、7、14 d挫伤灶周围HIF-1α、GLUT-3 mRNA 及蛋白的表达，并分析HIF-1α与GLUT-3 之间的相关性，采用免疫组化检测伤后14 d挫伤灶周围神经元核蛋白(NeuN)阳性表达率来观察神经元存活情况。多组间比较行单因素方差分析，用LSD 法行两两比较分析2组间差异，相关性分析用Pearson相关分析，以P＜0.05为差异具有统计学意义。

结果

TBI 组伤后4 h 至3 d HIF-1α、GLUT-3 的表达均明显增加(P＜0.05)。HPCT组HIF-1α及GLUT-3的表达在伤后1 h即增强，伤后4 h至7 d HIF-1α、GLUT-3表达量和伤后14 d NeuN阳性细胞数均明显高于TBI组，差异均具有统计学意义(P＜0.05)。相关性分析表明HIF-1α与GLUT-3 mRNA及蛋白的表达均呈正相关。

结论

HPC可通过诱导皮层脑组织HIF-1α的表达，上调GLUT-3 mRNA及蛋白的表达，进而提高TBI后急性期神经元的存活率。

Objective

To investigate the effect of hypoxic preconditioning (HPC) on the expression of hypoxia-inducible factor-1α, glucose transporter-3 and neuronal survival in cerebral cortex in rats with traumatic brain injury (TBI).

Methods

A total of 120 SD rats were randomly assigned to control group (CON, n=12), traumatic brain injury group (TBI, n=54) and traumatic brain injury after HPC group (HPCT, n=54). The rats of TBI group were established the TBI model by Feeney free falling dart impact method; The rats of HPCT group were treated with HPC (50.47 kPa,3 h/d,3 d)firstly,and then establish the HPCT model by Feeney free falling dart impact method.Detect the expression of HIF-1α、GLUT-3 mRNA and protein around the contusion focus on 1h, 4h, 8h,12h, 1d, 3d, 7d, 14d post-injury by RT-PCR and Western blotting, analysis the relevance between HIF-1α and GLUT-3, observe the neuronal survival situation of NeuN positive expression rate around the contusion focus by immunohistochemistry in 14 d post-injury. Take single factor analysis of variance among groups, analyzed by multiple comparisons with LSD method,correlation analysis with Pearson correlation analysis method, set P＜0.05 as the statistically significant difference.

Results

TBI group, both HIF-1α and GLUT-3 increased expression significantly on 4h, 8h, 12h, 1d and 3d post-injury(P＜0.05).HPCT group,both HIF-1α and GLUT-3 increased expression on 1h post-injury,the expression of HIF-1α and GLUT-3 on 4h to 7d post-injury and the count of NeuN positive cells 14d post-injury were both significantly higher than TBI group (P＜0.05). Correlation analysis showed that the expression of HIF-1α and GLUT-3 mRNA and protein were positive correlated.

Conclusion

HPC can induce the expression of HIF-1α in the cortical brain tissue, raise the expression of GLUT-3 mRNA and protein,and improve the acute neuronal survival rate post-injury of TBI.