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. Key words: Reperfusion injury; Endoplasmic reticulum; Cell apoptosis; Cysteine protein