bcl-xL基因转染对脊髓损伤半胱氨酸蛋白酶-3表达的影响

目的 探讨bcl—xL基因转染对大鼠脊髓损伤Caspase-3表达的影响和对神经细胞的保护作用。方法 制备大鼠胸段脊髓T8,9压迫损伤模型，随机分为2组：对照组．bcl—xL组，将阳离子脂质体质粒混合后直接注入大鼠损伤脊髓，伤后1、3和7d利用半定量逆转录-聚合酶链式反应（RT—PCR）和免疫组织化学检测bcl—xL和Caspase-3表达情况；TUNEL法检测细胞凋亡，观察对神经细胞的保护作用。结果 与对照组相比，bcl—xL组各时间段Caspase-3表达明显降低（P〈0．05），TUNEL阳性凋亡的神经细胞明显减少（P〈0．05）。结论 外源性bcl—xL基因体内转染在损伤脊髓的过度表达可减少脊髓不完全性损伤后凋亡，可能与其下调Caspase-3的有关。

The effect of bcl-xL gene transfection in vivo on the expression of Caspase-3 and neuroprotective function following spinal cord injury

Objective To investigate the effect of bcl-xL gene transfection on the expression of Caspase-3 and neuroprotective functionl in rat spinal cord compression injury model.Methods Models of acute spinal cord compression injury at the level of T8,9 were set up.The rats were divided into control group and bcl-xL group.The rats of bcl-xL group were subjected to the intraspinal injection of pSFFV.bcl-xL complexed with liposome.The expression of bcl-xL and Caspase-3 at 1st day,3rn day or 7th day after injection was detected by RT-PCR and immunostaining.The segments of injuried spinal cord were harvested for morphological studies after injury.By using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) methods,cell apoptosis was detected.Results Compared to control group,the expression of Caspase-3 was significantly decreased (P< 0.05) and the number of TUNEL labeling positive cells was less at different time points (P< 0.05) in bcl-xL gene transfecting group.Conclusion bcl-xL overexpressed by gene transfecting in injured spinal cord tissue could decrease the post-traumatic apoptosis,which might be correlate with the down-regulation of Caspase-3.