大鼠脑损伤后caspase-3表达的时间规律性研究

Dynamically changes of caspase-3 and the gene expression of caspase-3 mRNA after traumatic brain injury in rats

目的 :探讨大鼠脑损伤后半胱天冬酶 3(caspase 3)在神经元、神经胶质细胞表达的时间规律性。 方法 :以冲击应力σd为 35 5 .0 9kPa致大鼠脑损伤后不同时间段分别应用原位杂交、免疫组化、免疫组化双染色技术检测caspase 3mRNA和蛋白的表达强度 ,用图像分析系统测定阳性反应物平均灰度 ,进行统计学处理。结果 :caspase 3mRNA及蛋白在对照组为弥散分布 ,弱表达 ;分别于伤后 15 ,30min表达开始呈现增强趋势 ,至伤后 1d ,表达达到峰值 ,平均灰度值分别为 12 9.76± 2 .79,12 8.13± 1.97,与对照组、伤后 12h组比较均具有显著性差异 (P <0 .0 5 ) ,并维持高水平表达分别至伤后 7d(12 3.34± 1.6 0 )、伤后 4d(12 0 .34± 2 .96 ) ,与对照组比较均具有显著性差异(P <0 .0 5 )。免疫组化双染结果显示 ,伤后阳性细胞包括神经元和星形胶质细胞。结论 :脑损伤后caspase 3mR NA及蛋白的表达具有一定的时间规律性 ,可运用于法医学推断脑损伤的形成时间。

Objective: To illuminate the relationship between the expression of cysteinyl asparate-specific proteinase 3 (caspase-3) and the time course of traumatic brain injury (TBI).Methods: Model of TBI was produced by force of 355.09 kPa.Immunohistochemical staining,double-labeled with the anti-caspase-3 antibody and either the neuron-specific antibody NeuN or the astroglial-specific antibody GFAP,in situ hybridization and computer image analysis were used.Results: The immunostained cells of caspase-3 mRNA and protein were faint at control cortex. The darker cells were observed 15,30 minutes after injury. The darkest staining cells were also seen 1 day after injury,with respective average grey degree 129.76±2.79 and 128.13±1.97. Significant differences were present with both control and 12 hours post-injury ( P <0.05). The darker cells of caspase-3 mRNA and protein persisted in a high level until 7 days and 4 days post-injury respectively,with average grey degree 123.34 ±1.60,120.34±2.96. Both had significant differences ( P <0.05) with control group. The double-labeled of immunohistochemistry staining showed that the positive cells included neurons and astrocytes.Conclusion: The expressions of caspase-3 mRNA and protein had a possible relationship with the extended periods of time after TBI. It might be used to determine time course of TBI for forensic medicine.