大鼠全脑缺血再灌注后HAX-1蛋白与皮质神经元凋亡的关系

Relationship between HAX-1 expression and neuron apoptosis after cerebral ischemia reperfusion injury in rats

目的探讨大鼠全脑缺血再灌注后皮质组织中HAX-1蛋白(HS1-associated protein X-1,HAX-1)与皮质神经元凋亡的关系。方法建立大鼠四血管法全脑缺血模型,将实验动物分为5组(n=5):正常组,缺血6、24、48、72h组。采用HE染色,观察大鼠皮层组织病理变化;采用免疫组化、TUNEL法检测大鼠全脑缺血再灌注后HAX-1蛋白的表达以及皮质神经元凋亡蛋白Caspase-3的表达情况。结果HAX-1蛋白在缺血后6h表达最高(37.60±3.45),24、48、72h降低[分别为(11.40±1.14)、(10.40±1.52)、(9.80±1.30)],且低于正常水平(P<0.01);Caspase-3蛋白随着缺血时间的延长逐渐增高[6、24、48、72h分别为(72.80±5.49)、(106.20±6.91)、(129.00±19.74)、(166.20±15.32)](P<0.01),并伴随神经元凋亡的数目逐渐增加[(92.00±9.06)、(133.80±10.64)、(157.00±10.83)、(187.80±14.96)]。结论全脑缺血再灌注后皮质神经元中HAX-1蛋白在短期缺血中表达升高,可能参与神经元的抗凋亡,随着缺血时间延长,其表达水平降低,与神经元的凋亡增强相关。

Objective To investigate the relationship between HS1-associated protein X-1 （HAX-1） expression and neuron apoptosis in rats after global cerebral ischemia reperfusion injury. Methods Rats were subjected to global cerebral ischemia reperfusion injury through four-vessel occlusion, and then the experimental rats were divided into 5 groups, normal group （ NC ）, 6, 24, 48 and 72 h post injury groups （ n = 5 for each group）. Immunohistochemistry and TUNEL were used to detect HAX-1 expression and activated Caspase-3, and cell apoptosis in cortex of rats. Results The expression level of HAX-1 in ischemic cortex was peaked at 6 h （37.60 ±3.45）, then decreased at24, 48 and72 h （11.40 ±1.14, 10.40 ±1.52, and 9.80 ±1.30 respectively）, to an extend lower than the normal level （P 〈 0.01 ）. The expression of Caspase-3 in ischemic cortex was up-regulated after global cerebral ischemia reperfusion injury in rats with the prolongation of injury time （72.80 ±5.49, 106.20 ±6.91, 129.00 ±19.74, and 166.20 ±15.32 respectively for 6, 24, 48 and 72 h post inury）. The number of apoptotic cells was increased obviously with the elapse of time （92.00 ±9.06, 133.80 ±10.64, 157.00 ±10.83, and 187.80 ±14.96 respectively for 6, 24, 48 and 72 h post injury, P 〈 0.01 ）. Conclusion The expression of HAX-1 reachs a peak in a short time after global ischemia reperfusion injury, suggesting it may be involved in the anti-apoptosis of neuron apoptosis. With the elapse of injury time, its expression is decreased and associated with the increase of apoptotic cells.