大鼠脊髓缺血再灌注损伤中Ire1α、caspase-12的表达与细胞凋亡

目的 观察在大鼠脊髓缺血再灌注损伤过程中Ire1α与caspase-12的表达变化规律及其与神经细胞凋亡的关系. 方法 健康成年SD大鼠55只,用随机数字表法分为2组:(1)脊髓压迫缺血再灌注组(手术组,50只大鼠),每个时相点10只,采用自制压迫装置制备脊髓压迫缺血再灌注模型;(2)假手术对照组(手术组,5只大鼠),只做全椎板切除不做脊髓压迫.用TUNEL、免疫组化、Western blot和免疫荧光标记等方法 ,分别于缺血再灌注后1,4,8,16和24 h检测压迫段脊髓组织中细胞凋亡以及lre1α,caspase-12的表达变化情况. 结果 细胞凋亡数量随着缺血再灌注时间的延长而增加.手术组Ire1α、caspase-12的阳性细胞数及蛋白量于再灌注1 h开始增加,16 h达峰值,24 h开始减少,但仍然高于假手术对照组(P＜0.05). 结论 Ire1α与caspase-12共同参与了内质网应激介导的神经细胞凋亡.

Neuronal apoptosis and expressions of Ire1α and caspase-12 in rats with spinal cord ischemia reperfusion injury

Objective To investigate the expression changes of Ire1α and caspase-12 in rats with spinal cord ischemia-reperfusion injury.Methods Fifty-five adult SD rats(250-300 g)were randomly divided into control group(re=5)and operation group(n=50).The spinal cord ischemia-reperfusion models were established and the neuronal apoptosis was detected by terminal deoxynucleotidyl transferasemediated dUTP nick end labeling(TUNEL).The expressions of Ire1α and caspase-12 in spinal cord tissue were detected by immunohistochemistry,immunofluorescence and Western blot analysis at 1,4,8,16and 24 hours after ischemia-reperfusion.Results TUNEL staining showed that the number of apoptotic cells was gradually elevated with time.The expressions of Ire 1α and caspase-12 were increased at 1 hour after reperfusion,and peaked at 16 hours,but began to decline at 24 hours after reperfusion.The number of neurons with positive expressions of Irelaand caspase-12 was significantly higher than that of control group(P＜0.05).Conclusion Ire 1α and caspase-12 synergistically participate in the neuronal apoptosis induced by the endoplasmic reticulum stress.