iASPP在大鼠脑缺血再灌注中的表达及其意义

目的 观察p53凋亡刺激蛋白（apoptosis stimulating protein of p53，ASPP）家族的抑制因子（inhibitorymember of the ASPP family，iASPP）在大鼠脑缺血再灌注后的表达及其意义。方法 48只清洁级、成年健康雄性SD大鼠随机分为假手术组（8只）和脑缺血再灌注组（40只）。脑缺血再灌注组又分为缺血2h再灌注4h、12h、24h、48h和72h 5个时间点，其中每个时间点8只大鼠。苏木素-伊红染色测定脑梗死体积；原位末端转移酶标记技术检测半暗带细胞凋亡情况；免疫印迹法测定半暗带iASPP的表达变化。结果 脑缺血再灌注4h组和24h组的凋亡细胞阳性率与假手术组存在统计学差异（P <0.01）。脑缺血再灌注组的脑梗死体积百分比与假手术组相比具有统计学意义（P <0.05）。与假手术组相比，在脑缺血再灌注12h时iASPP表达开始下降（P <0.01），再灌注24h降至最低（P <0.01），再灌注48h开始回升（P <0.01）。结论 在脑缺血再灌注后，缺血半暗带凋亡细胞显著增多，iASPP表达下降，提示在脑缺血再灌注中iASPP的表达下降可能在细胞凋亡的发生中发挥重要作用，其表达上调可能具有神经保护作用。

The Expression and Significance of iASPP in Rats with Focal Cerebral Ischemia-Reperfusion

Objective To observe the expression and significance of iASPP （inhibitory member of the ASPP family） in rats with focal cerebral ischemia-reperfusion. Methods All rats were randomly divided into sham group （n=8） and cerebral ischemia-reperfusion group （n=40）. Five time points were set in cerebral ischemia-reperfusion group： 2, 4, 12, 24, 48 as well as 72 hours after 2 hours ischemia and reperfusion, ecah group have 8 rats. The volume of cerebral infarction was detected by hematoxylin-eosin （HE） staining. Apoptosis after focal ischemia was examined with TUNEL （Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling） staining. The expression level of iASPP was observed by Western blot analysis. Results The positive rate of apoptotic cells in the cerebral ischemia-reperfusion group at 24 h after reperfusion was higher than that in sham group, which showed statistical significance （P〈0.01）. The infarct volume in cerebral ischemia-reperfusion subgroups at 12h, 24h, 48h and 72h after reperfusion was larger than that in sham group respectively （P〈0.05）. Compared with the sham group, the expression level of iASPP protein in penumbra region began to decrease at 12h after reperfusion （P〈0.01）, reached the lowest point at 24h after reperfusion （P〈0.01）, and then began to increase at 48h （P〈0.01）. Conclusion After cerebral ischemia-reperfusion, the quantity of apoptotic cells increased and the expression level of iASPP decreased, which suggests that low expression of iASPP may play an important role in apoptosis of cerebral ischemia-reperfusion and high expression of iASPP may have neuroprotective effects.