Zhao Sanjun, Zhu Yajing, Xue Rui, Li Yunfeng, Lu Hui, Mi Weidong
Department of Anesthesiology, the General Hospital of Chinese PLA, Beijing 100853, China.
Department of Obstetrics and Gynecology, Luhe Teaching Hospital, Capital Medical University, Beijing 101100, China.
Neural Regen Res. 2012 Jul 5;7(19):1475-82. doi: 10.3969/j.issn.1673-5374.2012.19.005.
In many recent studies, the inhibitory transmitter gamma-aminobutyric acid has been shown to modulate the proliferation, differentiation and survival of neural stem cells. Most general anesthetics are partial or allosteric gamma-aminobutyric acid A receptor agonists, suggesting that general anesthetics could alter the behavior of neural stem cells. The neuroprotective efficacy of general anesthetics has been recognized for decades, but their effects on the proliferation of neural stem cells have received little attention. This study investigated the potential effect of midazolam, an extensively used general anesthetic and allosteric gamma-aminobutyric acid A receptor agonist, on the proliferation of neural stem cells in vitro and preliminarily explored the underlying mechanism. The proliferation of neural stem cells was tested using both Cell Counting Kit 8 and bromodeoxyuridine incorporation experiments. Cell distribution analysis was performed to describe changes in the cell cycle distribution in response to midazolam. Calcium imaging was employed to explore the molecular signaling pathways activated by midazolam. Midazolam (30-90 μM) decreased the proliferation of neural stem cells in vitro. Pretreatment with the gamma-aminobutyric acid A receptor antagonist bicuculline or Na-K-2Cl cotransport inhibitor furosemide partially rescued this inhibition. In addition, midazolam triggered a calcium influx into neural stem cells. The suppressive effect of midazolam on the proliferation of neural stem cells can be partly attributed to the activation of gamma-aminobutyric acid A receptor. The calcium influx triggered by midazolam may be a trigger factor leading to further downstream events.
在许多近期研究中，抑制性递质γ-氨基丁酸已被证明可调节神经干细胞的增殖、分化和存活。大多数全身麻醉药是部分或变构γ-氨基丁酸A受体激动剂，这表明全身麻醉药可能会改变神经干细胞的行为。全身麻醉药的神经保护作用已被认可数十年，但其对神经干细胞增殖的影响却很少受到关注。本研究调查了广泛使用的全身麻醉药和变构γ-氨基丁酸A受体激动剂咪达唑仑对体外神经干细胞增殖的潜在影响，并初步探讨了其潜在机制。使用细胞计数试剂盒8和溴脱氧尿苷掺入实验检测神经干细胞的增殖。进行细胞分布分析以描述咪达唑仑作用下细胞周期分布的变化。采用钙成像技术探索咪达唑仑激活的分子信号通路。咪达唑仑（30-90μM）可降低体外神经干细胞的增殖。用γ-氨基丁酸A受体拮抗剂荷包牡丹碱或钠-钾-2氯共转运抑制剂呋塞米预处理可部分逆转这种抑制作用。此外，咪达唑仑可引发神经干细胞内的钙内流。咪达唑仑对神经干细胞增殖的抑制作用部分归因于γ-氨基丁酸A受体的激活。咪达唑仑引发的钙内流可能是导致进一步下游事件的触发因素。
