积雪草酸调节cAMP/CREB/BDNF信号通路对七氟醚诱导的新生大鼠神经毒性的影响

Impacts of asiatic acid on sevoflurane-induced neurotoxicity in neonatal rats by regulating cAMP/CREB/BDNF signaling pathway

目的探究积雪草酸(AA)调节环磷酸腺苷(cAMP)/cAMP反应元件结合蛋白(CREB)/脑源性神经营养因子(BDNF)信号通路对七氟醚诱导的新生大鼠神经毒性的影响。方法将SD大鼠随机分为对照组(Control组)、模型组(Model组)、AA低剂量组(AA-L组,10 mg/kg)、AA高剂量组(AA-H组,20 mg/kg)和AA高剂量+cAMP抑制剂SQ22536组(AA-H+SQ22536组,AA 20 mg/kg+2.22 mg/kg SQ22536)。Y迷宫实验、Morris水迷宫实验检测大鼠的空间认知能力。酶联免疫吸附实验法(ELISA)测定大鼠血清和海马组织中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)和丙二醛(MDA)的水平和海马组织中cAMP含量。TUNEL法检测大鼠海马组织神经细胞凋亡。实时荧光定量聚合酶链反应(RT-qPCR)检测大鼠海马组织中CREB、BDNFmRNA的表达;Westernblot检测大鼠海马组织中p-CREB、BDNF蛋白的表达。结果与Control组相比,Model组大鼠海马组织神经细胞凋亡率、第4、5天的逃逸潜伏期、血清和海马组织中MDA水平显著增加(P<0.05);交替得分率、目标象限停留时间、血清和海马组织中SOD、GSH-px水平、海马组织CREB、BDNF mRNA表达水平和cAMP、p-CREB和BDNF蛋白表达水平显著减少(P<0.05)。与Model组相比,AA-H组大鼠相应指标变化趋势与上述相反。SQ22536减弱了AA对七氟醚诱导的新生大鼠神经毒性的抑制作用。结论AA可能通过上调cAMP/CREB/BDNF信号通路减轻七氟醚诱导的新生大鼠神经毒性。

Objective To investigate the impacts of asiatic acid(AA)on sevoflurane-induced neurotoxicity in neonatal rats by regulating cyclic adenosine monophosphate(cAMP)/cAMP response element binding protein(CREB)/brain-derived neurotrophic factor(BDNF)signaling pathway.Methods SD rats were randomly grouped into Control group,Model group,AA low-dose group(AA-L group,10 mg/kg),and AA high-dose group(AA-H group,20 mg/kg)and AA high-dose+cAMP inhibitor SQ22536 group(AA-H+SQ22536 group,AA 20 mg/kg+2.22 mg/kg SQ22536).Y-maze test and Morris water maze test were applied to test the spatial cognition ability of rats.Enzyme-linked immunosorbent assay(ELISA)was applied to determine the expression levels of superoxide dismutase(SOD),glutathione peroxidase(GSH-px)and malondialdehyde(MDA)in rat serum and hippocampus tissue and the cAMP content in the hippocampus of rats.TUNEL method was applied to detect neuronal apoptosis of rat hippocampus.Real-time quantitative polymerase chain reaction(RT-qPCR)was applied to detect the expression of CREB and BDNF mRNA in rat hippocampus.Western blot was applied to detect the expression of p-CREB and BDNF proteins in rat hippocampus.Results Compared with the Control group,the apoptosis rate of neurons of the hippocampus,the escape latency on the 4th and 5th days,and the level of MDA in the serum and hippocampus were obviously increased in the Model group(P<0.05).The alternate score rate,target quadrant residence time,the levels of SOD,GSH-px in serum and hippocampus,the mRNA expression levels of CREB and BDNF,and the protein expressions of cAMP,p-CREB and BDNF in hippocampus were obviously decreased(P<0.05).Compared with the Model group,the change trend of the corresponding indicators in the AA-H group was opposite to the above.SQ22536 attenuated the inhibitory effect of AA on sevoflurane-induced neurotoxicity in neonatal rats.Conclusion AA may alleviate sevoflurane-induced neurotoxicity in neonatal rats by up-regulating cAMP/CREB/BDNF signaling pathway.