SGLT1参与阿莫达非尼降低岛叶皮层活性缓解帕金森病相关焦虑障碍的机制研究

Anxiety disorders relating to Parkinson's disease (PD) present a high incidence and seriously affect the quality of life in PD patients. While the pathogenesis of anxiety disorders relating to PD is not clear. Increased activity of insular cortex plays a key role in the onset of anxiety disorders relating to PD. Our previous studies showed that armodafinil significantly reduced insular cortex activity of PD rats, inhibited their anxiety-like behavior, causing increased expression of Per1 and decreased expression of Na+-glucose cotransporter 1 (SGLT1) in insular cortex. The literature have confirmed that Per1 can inhibit the expression of SGLT1. High expression of SGLT1 can cause increased uptake of glucose, and increased energy metabolism in neurons. It is speculated that armodafinil might reduce the expression of SGLT1 through increasing the expression of Per1 in neurons of insular cortex, and then normalize the glucose transport and energy metabolism of neurons, resulting in normalized insular cortex activity and alleviated anxiety disorders relating to PD. In this project, we intend to employ 6-OHDA induced rat model of PD, and study the effect of armodafinil on insular cortex activity and anxiety-like behavior of experiment animals on overall level. Then we intend to study the role and mechanism of SGLT1 in regulation of neuronal glucose uptake and energy metabolism by armodafinil on cellular and molecular level. This project can provide experimental evidence for searching new drug targets of anxiety disorders relating to PD.

帕金森病（PD）相关焦虑障碍在PD患者中发生率高，严重影响患者生活质量，发病机制尚无定论。PD病程中岛叶皮层活性增高是引发焦虑障碍的关键因素。前期研究显示，阿莫达非尼能显著降低PD大鼠岛叶皮层活性，抑制其焦虑样行为，并使岛叶皮层Per1表达增加，钠-葡萄糖协同转运蛋白1 (SGLT1)表达下降。文献证实Per1可抑制SGLT1表达，而神经元SGLT1表达上升会引起其葡萄糖摄取增加及能量代谢增强，导致局部皮层活性增高。故推测阿莫达非尼可能通过增加Per1表达下调SGLT1使岛叶皮层神经元的葡萄糖转运和能量代谢趋于正常，从而使岛叶皮层活性恢复正常，减轻PD相关焦虑障碍。本项目拟以6-OHDA诱导的PD大鼠为对象，从整体水平研究阿莫达非尼对动物岛叶皮层活性及焦虑样行为的影响，从细胞及分子水平探讨SGLT1参与阿莫达非尼调节岛叶皮层神经元葡萄糖转运和能量代谢的机制，为寻找新的药物靶点提供实验依据。

焦虑障碍是帕金森病(Parkinson’s disease, PD)患者中常见的非运动系统症状，发生率高，严重影响患者生活质量。PD相关焦虑障碍很大程度上源于PD特异的脑器质性病变，目前缺乏针对性的治疗方案，且对PD相关焦虑障碍的具体发病机制尚无定论。PD病程中岛叶受到累及，发生神经病理改变，功能出现异常，并与PD相关的情感/行为障碍的发生有着密切关系。阿莫达非尼作为一种新型中枢促觉醒剂，能够改善PD患者的整体精神状态，并对暴食症、强迫症等精神障碍有着较好的疗效。本研究旨在探讨阿莫达非尼对PD相关焦虑障碍能否起到缓解作用以及其作用的分子机制。结果显示，采用6-OHDA左侧纹状体注射法制备PD模型大鼠，腹腔给药10 mg/kg/d的阿莫达非尼，给药两天后和最后一次给药结束时岛叶定点注射Per1抑制剂PF670462 10 μg，持续5天后，锰离子增强磁共振成像检测岛叶皮层活性显示阿莫达非尼组的岛叶皮层活性显著低于生理盐水对照组，PF670462可以显著抑制阿莫达非尼引起的岛叶皮层活性降低；通过旷场实验、高架十字迷宫实验显示阿莫达非尼可以显著缓解PD大鼠的焦虑样行为，PF670462对阿莫达非尼的缓解作用产生拮抗效果；通过实时荧光定量PCR、Western blot检测大鼠岛叶皮层Per1和SGLT1的 mRNA 和蛋白水平发现，阿莫达非尼可以增加岛叶Per1表达，降低SGLT1表达，而PF670462可以降低阿莫达非尼对PD大鼠岛叶Per1及SGLT1的影响；说明阿莫达非尼通过上调Per1而降低SGLT1表达从而降低PD大鼠岛叶皮层活性。原代培养PD大鼠岛叶神经元，采用10μM阿莫达非尼或阿莫达非尼合并20μM PF670462处理48小时，用2-NBDG检测神经元葡萄糖摄取，并用荧光素-荧光素酶实验测定神经元ATP含量，显示阿莫达非尼能够显著降低PD鼠神经元的葡糖摄取及ATP含量，PF670462可以拮抗此效应，表明阿莫达非尼是通过降低PD大鼠岛叶皮层神经元的葡萄糖摄取和能量代谢水平从而降低岛叶神经活性。本研究从整体、细胞及分子水平研究阿莫达非尼缓解PD相关焦虑障碍的作用，阐明阿莫达非尼通过上调Per1而降低SGLT1表达，使岛叶神经元的葡萄糖转运和能量代谢趋于正常，从而使岛叶皮层活性恢复正常，缓解PD相关焦虑障碍的作用机制，为寻找新的药物靶点提供依据。