NF-κB信号通路对心肺复苏后大鼠脑AQP-4 mRNA表达的调控作用

Effect of nuclear factor -κB signaling pathway on the expression of aquaporin-4 mRNA in rat brain after cardiopulmonary resuscitation

目的观察心肺复苏后大鼠脑NF-κB活性变化对水通道蛋白-4(AQP-4)mRNA表达的影响,探讨心肺复苏后大鼠脑AQP-4 mRNA表达调控的可能机制。方法雄性Sprague-Dawley大鼠54只,随机分为假手术组(A组,6只)、复苏加生理盐水组(B组,24只)和复苏加吡咯烷二硫代氨基甲酸盐(pyrrolidine dithiocarbamate,PDTC)组(C组,24只),B组和C组又分为自主循环恢复(restoration of spontaneous circulation,ROSC)3、6、12、24h四个亚组,每个亚组各6只。各组均进行呼吸频率、心率、动脉血压等生命体征监测,应用免疫组织化学染色检测NF-κB活性改变,逆转录聚合酶链式反应(RT-PCR)测定AQP-4 mRNA的表达变化。结果B组和C组各亚组的NF-κB活性和AQP-4 mRNA表达与A组相比均明显增加(P<0.01),B、C两组NF-κB活性从ROSC后3h开始便持续升高,至ROSC24h达高峰,而AQP-4 mRNA的表达表现为先升高,于ROSC后12h达顶峰,24h出现下降。C组各时间点NF-κB活性和AQP-4 mRNA表达与B组同时间点相比明显下降(P<0.05),且ROSC后的前12h内的NF-κB活性变化与AQP-4 mRNA表达变化呈正相关(r>0.775,P<0.01)。结论心肺复苏后早期大鼠脑NF-κB活性增加,AQP-4 mRNA表达增强,NF-κB活化抑制剂PDTC能明显降低AQP-4 mRNA的表达,NF-κB信号通路的激活在心肺复苏后早期大鼠脑AQP-4 mRNA表达中可能起了重要的调控作用。

Objective To observe the effect of nuclear factor - κB （ NF - κB） signaling path- way on the expression of aquaporin - 4 mRNA in rat brain after cardiopulmonary resuscitation （ CPR ） and investigate the mechanism of the expression of aquaporin - 4 mRNA following PCR. Methods 54 male Sprague -Dawley rats were randomly divided into three groups：group A（ sham procedure,n = 6） ,group B B （control, n = 24） and group C （ nuclear factor - κB inhibitor pyrrolidine dithiocarbamate, PDTC, infusion, n = 24 ）. Group B and group C were again divided into 3,6,12,24 hours subgroups （ n = 6 ）. The cardiac arrest model of rat was duplicated by asphyxy method. Immunohistochemistry method was adopted to analyse the level of NF - κB p65 . AQP - 4 mRNA expression was assessed by semi - quantitative RTPCR. Result The levels of NF - κB p65 and AQP - 4 mRNA of group B and group C were significantly up - regulated at all time point after restoration of spontaneous circulation （ ROSC ） compared with group A （ P 〈 0.01 ）. The correlation analysis demonstrated further that the level of NF - κB p65 was correlated apparently with the AQP - 4 mRNA expression level in brain tissue within ROSC 12 h （ r 〉 0. 775, P 〈 0. 01）. AQP-4 mRNA expression reached peak at 12 hours after ROSC. PDTC resulted in a significant decrease in AQP - 4 mRNA expression in group C compared with group B （ P 〈 0.05 ）. Conclusion The levels of NF - κB 1365 and AQP -4 mRNA are increased at early stage after CPR, and inhibition of the NF - κB signaling pathway blocks the induction of AQP - 4 mRNA . These findings show that the NF - κB signaling pathway may play an important role in the expression of AQP - 4 mRNA after CPR in rat brain.