内质网应激相关CHOP在SAH后细胞凋亡中的作用及机制

Mechanism of apoptosis in endoplasmic reticulum stress-related CHOP after subarachnoid hemorrhage in rats

目的探讨内质网应激(endoplasmic reticulum stress,ERS)相关C/EBP同源蛋白(C/EBP homoiogousprotein,CHOP)在蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后神经元凋亡的作用机制。方法血管内穿刺方法建立大鼠SAH模型,脑室内给药建立SAH+sh-con组和SAH+sh-RNAi组,应用神经行为学评分法进行神经行为学评分,Real-time PCR检测Caspase-3、Bim、Bcl-2的mRNA表达,Western blot检测CHOP蛋白表达,TUNEL法检测神经元凋亡。结果 SAH组和SAH+sh-con组Caspase-3、Bim mRNA及CHOP蛋白表达较空白组明显增多,Bcl-2mRNA表达减少,神经元凋亡增多(P<0.05);与空白组比较,SAH+sh-RNAi组Caspase-3、Bim mRNA及CHOP蛋白表达增多,Bcl-2mRNA表达减少,神经元凋亡增多,差异有统计学意义(P<0.05),而与SAH组和SAH+sh-con组比较,Caspase-3、Bim mRNA及CHOP蛋白表达减少,Bcl-2mRNA表达增多,神经元凋亡减少,差异具有统计学意义(P<0.05);CHOP蛋白表达增多与神经元凋亡之间存在正相关(r=0.832,P<0.05)。结论 ERS凋亡通路参与了SAH后神经元凋亡过程,抑制CHOP蛋白表达可以有效减少凋亡以改善预后。

Objective To explore the mechanism of endoplasmic reticulum stress(ERS)C/EBP homologous protein homoiogousprotein(CHOP)on neuronal apoptosis after subarachnoid hemorrhage(SAH).Methods SAH model was established by endovascular perforation technique,intraventricular administration in SAH+sh-con group and SAH+sh-RNAi group.Neurological score was used to evaluate neurological behavior of the rats.Real-time PCR and Western blot were used to detect the expressions of caspase-3,Bim,Bcl-2 mRNA and CHOP protein.Neuronal apoptosis was detected by TUNEL.Results The expressions of Caspase-3 and Bim mRNA,and CHOP protein as well as neuronal apoptosis increased significantly;Bcl-2 mRNA decreased significantly in SAH group and SAH+sh-con group(P<0.05).The expressions of Caspase-3 and Bim mRNA,and CHOP protein as well as neuronal apoptosis decreased,while Bcl-2 mRNA expression increased in SAH+sh-RNAi group compared with SAH group and SAH+sh-con group(P<0.05).There was a positive correlation between the expression of CHOP protein and neuronal apoptosis(r=0.832,P<0.05).Conclusion Endoplasmic reticulum stress-apoptosis pathway is involved in the process of neuronal apoptosis after SAH.Inhibition of CHOP protein expression can effectively reduce apoptosis and improve prognosis.