Department of Anesthesiology, First Affiliated Hospital, Sun Yat-Sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Clinical Research Center for Cancer, Tianjin, 300060, People's Republic of China.
Neurochem Res. 2020 Sep;45(9):1986-1996. doi: 10.1007/s11064-020-03028-9. Epub 2020 May 6.
Numerous studies have shown that the inhaled general anesthetic sevoflurane imposes toxicity on the central nervous system during the developmental period but the underlying mechanisms remain unclear. Neuropeptide Y (NPY) was reported to have important neuroprotective effects, which can attenuate neuronal loss under pathological conditions. However, the effects of NPY on sevoflurane-induced hippocampal neuronal apoptosis have not been investigated. In this study, postnatal day 7 (PND7) Sprague-Dawley rats and primary cultured cells separated from hippocampi were exposed to sevoflurane (2.4% for 4 h) and the NPY expression levels after treatment were analyzed. Furthermore, neuronal apoptosis assay was conducted via immunofluorescence staining of cleaved caspase-3 and flow cytometry after exogenous NPY administration to PND7 rats as well as cultured hippocampal neurons to elucidate the role of NPY in sevoflurane-induced neurotoxicity. Our results showed the level of NPY gradually decreased within 24 h after sevoflurane exposure in both the hippocampus of PND7 rats and cultured hippocampal neurons, but not in cultured astrocytes. In the exogenous NPY pretreatment study, the proportion of cleaved caspase-3 positive cells in the CA1 region of the hippocampus was increased significantly at 24 h after sevoflurane treatment, while NPY pretreatment could reduce it. Similarly, NPY could also reverse the apoptogenic effect of sevoflurane on cultured neurons. Herein, our results showed that sevoflurane caused a significant decrease in NPY expression, whereas exogenous NPY supplementation could reduce sevoflurane-induced hippocampal neuronal apoptosis both in vivo and in vitro.
大量研究表明，吸入性全身麻醉剂七氟醚在发育期间对中枢神经系统造成毒性，但潜在机制尚不清楚。神经肽 Y（NPY）被报道具有重要的神经保护作用，可在病理条件下减轻神经元丢失。然而，NPY 对七氟醚诱导的海马神经元凋亡的影响尚未被研究。在这项研究中，对出生后第 7 天（PND7）的 Sprague-Dawley 大鼠和分离自海马的原代培养细胞进行七氟醚（2.4%，4 小时）暴露，并分析处理后的 NPY 表达水平。此外，通过对 PND7 大鼠和培养的海马神经元进行外源性 NPY 给药后的 cleaved caspase-3 免疫荧光染色和流式细胞术进行神经元凋亡测定，以阐明 NPY 在七氟醚诱导的神经毒性中的作用。我们的结果表明，在 PND7 大鼠海马和培养的海马神经元中，七氟醚暴露后 24 小时内 NPY 水平逐渐下降，但在培养的星形胶质细胞中没有下降。在外源性 NPY 预处理研究中，七氟醚处理后 24 小时，海马 CA1 区 cleaved caspase-3 阳性细胞的比例显著增加，而 NPY 预处理可降低其比例。同样，NPY 也可以逆转七氟醚对培养神经元的促凋亡作用。因此，我们的结果表明，七氟醚导致 NPY 表达显著下降，而外源性 NPY 补充可减少体内和体外七氟醚诱导的海马神经元凋亡。
