目的:探讨长链非编码核糖核酸-X染色体失活基因(lncRNA-XIST)对脊髓损伤大鼠神经元凋亡过程的影响及其作用机制。方法:将成年SD大鼠(北京中国科学院实验动物中心提供)随机分为假手术组、脊髓损伤组、观察组，假手术组接受椎板切除术，脊髓损伤组和观察组椎板切除后使用脊髓打击器损伤脊髓。假手术组和脊髓损伤组脊髓内注射空白慢病毒，观察组脊髓内注射转染慢病毒包装短发夹RNA(Lv-shRNA)的慢病毒，比较不同处理方式下各组大鼠运动功能评分、脊髓细胞凋亡及相关蛋白表达，多组间比较采用单因素方差分析(one-way ANOVA)，两组间比较采用n t检验。n 结果:在各不同时间点，假手术组大鼠运动功能评分[(21.36±3.52)、(22.16±3.22)、(22.15±4.12)、(21.52±3.25)、(24.26±6.21)、(22.45±6.14)分]显著高于脊髓损伤组[(0.45±0.21)、(1.26±0.26)、(3.12±1.02)、(4.38±1.05)、(10.02±3.45)、(11.14±3.59)分]和观察组[(4.52±2.13)、(6.23±1.02)、(10.14±2.88)、(12.02±3.25)、(16.25±4.25)、(18.05±2.14)分，n F＝9.505、8.425、2.302、9.565、4.825、3.052，n P<0.05]，差异均有统计学意义；脊髓细胞凋亡率[(4.25±0.56)%、(4.56±0.74)%、(5.12±1.02)%、(3.85±0.52)%]显著低于脊髓损伤组[(45.85±7.81)%、(43.87±6.85)%、(47.85±3.48)%、(44.85±6.25)%]和观察组[(23.42±3.25)%、(21.05±4.15)%、(26.45±5.87)%、(24.95±6.14)%，n F＝7.105、8.825、8.114、9.514，n P<0.05]，差异均有统计学意义；磷酸化-Akt、磷酸化-mTOR显著高于脊髓损伤组[(0.15±0.02)、(0.17±0.03)]和观察组[(0.85±0.05)、(0.74±0.03)，n F＝7.814、8.825，n P<0.05]，差异均有统计学意义。而观察组大鼠运动功能评分、磷酸化-蛋白激酶B(Akt)、磷酸化-雷帕霉素靶蛋白(mTOR)显著高于脊髓损伤组，细胞凋亡率显著低于脊髓损伤组。n 结论:长链非编码RNA-XIST可以通过促进磷脂酰肌醇3激酶(PI3K)/Akt信号通路活化，促进脊髓损伤的神经元凋亡。“,”Objective:To investigate the effect of long-chain noncoding RNA-XIST on neuronal apoptosis in rats with spinal cord injury (SCI) and its mechanism.Methods:Adult sprague dawley (SD) rats (purchased from the Laboratory Animal Center of the Chinese Academy of Sciences) were randomly divided into sham operation group, SCI group and observation group. The sham operation group received laminectomy. SCI group and observation group were injured by spinal cord percussion device after laminectomy. The rats in the sham operation group and the SCI group were injected with blank lentivirus. The rats in the observation group were injected with lentivirus transfected with lentivirus (LV) short hairpin RNA (shRNA). The Basso-Beattie-Bresnahan (BBB) score, apoptosis of spinal cord cells and the expression of related proteins were compared under different treatments.Results:At different time points, motor function scores of rats in sham operation group [(21.36±3.52), (22.16±3.22), (22.15±4.12), (21.52±3.25), (24.26±6.21), (22.45±6.14)] were significantly higher than those in SCI group [(0.45±0.21), (1.26±0.26), (3.12±1.02), (4.38±1.05), (10.02±3.45), (11.14±3.59)] and observation group [(4.52±2.13), (6.23±1.02), (10.14±2.88), (12.02±3.25), (16.25±4.25), (18.05±2.14),n F=9.505, 8.425, 2.302, 9.565, 4.825, 3.052, all n P<0.05]; The apoptosis rate of spinal cord cells in sham operation group [(4.25±0.56)%, (4.56±0.74)%, (5.12±1.02)%, (3.85±0.52)%] was also significantly lower than that in SCI group [(45.85±7.81)%, (43.87±6.85)%, (47.85±3.48)%, (44.85±6.25)%] and observation group [(23.42±3.25)%, (21.05±4.15)%, (26.45±5.87)%, (24.95±6.14)%,n F=7.105, 8.825, 8.114, 9.514, all n P<0.05]; Phosphorylated Akt and phosphorylated mTOR were also significantly higher in SCI group [(0.15±0.02), (0.17±0.03)] and observation group [(0.85±0.05), (0.74±0.03),n F=7.814, 8.825, all n P<0.05]. However, the motor function scores, phospho protein kinase B (Akt), and phospho mammalian target of rapamycin (mTOR) in the observation group were significantly higher than those in the SCI group, and the apoptosis rate was significantly lower than that in the SCI group.n Conclusion:Long-chain non coding RNA-XIST can promote the activation of phosphatidylinositol 3 kinase (PI3K)/Akt signal pathway and promote the apoptosis of neurons in SCI.