Lu Pan, Lei Shan, Li Weisong, Lu Yang, Zheng Juan, Wang Ning, Xia Yongjun, Lu Haixia, Chen Xinlin, Liu Yong, Zhang Peng-Bo
Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Department of Anesthesiology, Affiliated Hospital of Chinese People's Armed Police Engineering University, Xi'an, China.
Cell Physiol Biochem. 2018;47(4):1377-1388. doi: 10.1159/000490823. Epub 2018 Jun 19.
BACKGROUND/AIMS: Ketamine inhibits the proliferation of neural stem cells (NSCs) and disturbs normal neurogenesis. Dexmedetomidine provides neuroprotection against volatile anesthetic-induced neuroapoptosis and cognitive impairment in the developing brain. Whether it may protect NSCs from ketamine-induced injury remains unknown. In this study, we investigated the protective effects of dexmedetomidine on ketamine-exposed NSCs and explored the mechanisms potentially involved.
Primary NSC cultures were characterized using immunofluorescence. Cell viability was determined using a Cell Counting Kit 8 assay. Proliferation and apoptosis were assessed with BrdU incorporation and TUNEL assays, respectively. Protein levels of cleaved caspase-3, phosphorylated protein kinase B (p-Akt), and glycogen synthase kinase-3β (p-GSK-3β) were quantified using western blotting.
Ket-amine significantly decreased NSC viability and proliferation and increased their apoptosis. Dexmedetomidine increased NSC proliferation and decreased their apoptosis in a dose-dependent manner. Furthermore, dexmedetomidine pretreatment notably augmented the viability and proliferation of ketamine-exposed NSCs and reduced their apoptosis. Moreover, dexmedetomidine lessened caspase-3 activation and increased p-Akt and p-GSK-3β levels in NSCs exposed to ketamine. The protective effects of dexmedetomidine on ketamine-exposed NSCs could be partly reversed by the PI3K inhibitor LY294002.
Collectively, these findings indicate that dexmedetomidine may protect NSCs from ketamine-induced injury via the PI3K/Akt/GSK-3β signaling pathway.
背景/目的：氯胺酮可抑制神经干细胞（NSCs）的增殖并扰乱正常的神经发生。右美托咪定可对发育中大脑的挥发性麻醉药诱导的神经细胞凋亡和认知功能障碍起到神经保护作用。它是否能保护神经干细胞免受氯胺酮诱导的损伤尚不清楚。在本研究中，我们调查了右美托咪定对氯胺酮处理的神经干细胞的保护作用，并探讨了其中潜在的机制。
使用免疫荧光对原代神经干细胞培养物进行鉴定。使用细胞计数试剂盒8检测法测定细胞活力。分别通过BrdU掺入法和TUNEL检测法评估增殖和凋亡情况。使用蛋白质印迹法定量分析裂解的半胱天冬酶-3、磷酸化蛋白激酶B（p-Akt）和糖原合酶激酶-3β（p-GSK-3β）的蛋白水平。
氯胺酮显著降低了神经干细胞的活力和增殖，并增加了其凋亡。右美托咪定以剂量依赖性方式增加了神经干细胞的增殖并降低了其凋亡。此外，右美托咪定预处理显著增强了氯胺酮处理的神经干细胞的活力和增殖，并减少了其凋亡。此外，右美托咪定减轻了氯胺酮处理的神经干细胞中半胱天冬酶-3的激活，并增加了p-Akt和p-GSK-3β水平。右美托咪定对氯胺酮处理的神经干细胞的保护作用可被PI3K抑制剂LY294002部分逆转。
总体而言，这些发现表明右美托咪定可能通过PI3K/Akt/GSK-3β信号通路保护神经干细胞免受氯胺酮诱导的损伤。
