【摘要】 目的:探讨右美托咪定(dexmedetomidine,DEX)对大鼠胚胎神经干细胞(NSCs)增殖及分化的影响。方法:从孕14~16 d SD大鼠胚胎中分离NSCs并原代培养及Nestin鉴定。实验分为对照组、低浓度及高浓度DEX组,培养液中分别加入终浓度为0、1、10 ng/mL DEX。MTT法检测NSCs活性;5-溴脱氧尿(Brdu)法观察检测NSCs增殖;Western blot法检测增殖期NSCs中ERK1/2磷酸化;免疫荧光法标记神经元细胞、星形胶质细胞、少突胶质细胞和神经元干细胞观察细胞分化。结果:分离培养的神经干细胞95%以上呈Nestin阳性;低浓度DEX组MTT吸光值、Brdu阳性细胞及EKR1/2磷酸化水平较对照组明显增加(P<0.05),而高浓度DEX组较对照组及低浓度DEX组明显降低(P<0.05);高、低浓度DEX组中NeuN、GFAP及MBP阳性细胞数较对照组明显增加(P<0.05),Nestin阳性细胞则显著降低(P<0.05),而高、低浓度DEX组间无明显差异(P>0.05)。结论:低浓度DEX诱导体外培养大鼠神经干细胞增殖而高浓度DEX则抑制其增殖,其机制可能通过调节EKR1/2磷酸化;高、低浓度DEX均诱导神经干细胞非选择性分化。更多还原

【Abstract】 Objective To investigate the effect of dexmedetomidine(DEX) on proliferation and differentiation of rat embryonic neural stem cells in vitro. Methods Embryonic neuraI stem cells of fetal SD rats were separated from rats with gestational age of 14-16 days, and underwent primary culture for nestin expression. Cells were divided into control group, low-dose DEX group, and high-dose DEX group, which were cultured with 0,1 and 10 ng /mL DEX respectively. Cell viability was detected by MTT assay;the proliferation rate was estimated by BrdU incorporation; the phosphorylation of ERK1 / 2 in the proliferation phases was detected by western blot; the differentiation of neuronal cells,astrocytes,oligodendrocyte and neural stem cells were assessed by immunocytochemistry of cell specific markers. Results More than 95% of the embryonic neural stem cells in primary culture were Nestin-positive. Cell viability, BrdU-positive cells and phosphorylation of ERK1 / 2 in low-dose DEX group increased significantly(P < 0.05), and decreased significantly in high-dose DEX group compared with control group and low-dose DEX group(P < 0.05). NeuN-, GFAP- and MBP-positive cells increased(P < 0.05),while Nestin-positive cell decreased(P < 0.05) in both low and high dose DEX group compared with control group.However, no significant difference was found in low and high dose DEX group(P > 0.05). Conclusions The proliferation of neuraI stem cells can be promoted by low-dose DEX and depressed by high-dose DEX, as well as regulated by DEX of the phosphorylation of ERK1 / 2. DEX induces neural stem cells non-selective differentiation.更多还原