低剂量七氟醚调节海马神经元凋亡、减轻心肺转流术后认知功能障碍的机制研究

Mechanism of Low-dose Sevoflurane Regulating Hippocampal Neuron Apoptosis and Attenuating Cardiopulmonary Bypass(CPB)-induced Postoperative Cognitive Dysfunction

目的探究低剂量七氟醚调节海马神经元凋亡、减轻心肺转流术(CPB)后认知功能障碍(POCD)的作用机制。方法用老年SD雄性大鼠构建CPB诱导POCD模型,并通过使用原代海马神经元(PHN)诱导体外缺氧/复氧(H/R)模型,再以低剂量七氟醚干预,通过流式细胞术、CCK-8、台盼蓝染色、Western blot等方法检测海马神经元增殖与凋亡和相关蛋白表达情况。结果CPB损害了大鼠认知功能并诱导海马神经元凋亡,可通过低剂量七氟醚预处理减轻海马神经元凋亡。CPB诱导POCD大鼠海马组织中PI3K/AKT信号通路被抑制,低剂量七氟醚可逆转该信号通路的抑制作用。PI3K/AKT抑制剂(LY294002)可逆转低剂量七氟醚对CPB诱导POCD大鼠的保护作用。体外结果显示,H/R处理可诱导PHN细胞凋亡并抑制其细胞活力,而低剂量七氟醚提高了PHN细胞活力,且LY294002逆转了低剂量七氟醚对H/R诱导PHN细胞凋亡的改善作用。结论低剂量七氟醚通过激活PI3K/AKT信号通路抑制海马神经元凋亡,从而减轻CPB诱导的POCD。

Objective To explore the mechanism of low-dose Sevoflurane regulating hippocampal neuron apoptosis and attenuating cardiopulmonary bypass(CPB)-induced postoperative cognitive dysfunction(POCD).Methods The CPB-induced POCD models were established by using elderly Sprague-Dawley(SD)male rats,and hypoxia/reoxygenation(H/R)models were inducted by using the primary hippocampus neuron(PHN)in vitro,and then low-dose Sevoflurane was used for intervention.The proliferation and apoptosis of neurons in hippocampus neuron as well as expressions of related proteins were detected by using flow cytometry,CCK-8,trypan blue staining and Western blot.Results CPB impaired cognitive functions and induced hippocampus apoptosis in rat models,which were alleviated by pretreating rats with low-dose Sevoflurane.In addition,the phosphatidylinositol 3 kinase/protein kinase B(PI3K/AKT)signal pathway was inhibited in hippocampus tissues of CPB-induced POCD rats,which was inversed by low-dose Sevoflurane treatment.PI3K/AKT inhibitor(LY294002)could inverse the protective effects of low-dose Sevoflurane on CPB-induced POCD rats.Results of in vitro examination showed that H/R treatment induced cell apoptosis and inhibited cell viability in PHN cells,while low-dose Sevoflurane improved cell viability in PHN cells.Similarly,LY294002 inversed the improved effects of low-dose Sevoflurane on apoptosis in H/R-induced PHN cell.Conclusion Low-dose Sevoflurane may reduce CPB-induced POCD by inhibiting hippocampal neuronal apoptosis through activating PI3K/AKT signal pathway.