SENP3介导PML蛋白去SUMO化调控七氟醚致发育期学习记忆障碍的作用机制研究

The long-term effect of anesthetic agents exposure on developing brain is a focus of the anesthesia and perioperative medicine. It has been conclusively demonstrated that neurogenesis in the hippocampus is crucial for learning and memory. However, its underlying mechanisms are poorly understood, especially in protein post-translational modification. Studies have shown that promyelocytic leukemia protein (PML) SUMOylation is involved in regulating the differentiation and migration of neural stem cells, and is closely related to the developing brain neurogenesis. Our previous study showed that a decreased neurogenesis in neonatal mice hippocampus, which were correlated with neuronal migration inhibitory protein Slit2 and specific protease SENP3 expression continued to increase. Based on the above investigations, we hypothesized that sevoflurane exposure could activate Slit2 signaling pathway due to the increase of the level of PML de-SUMO mediated by SENP3, and result in neonatal neuronal dysfunction and migration abnormalities, which eventually lead to neonatal mice learning and memory function decline. To verify this hypothesis, we used gene engineering to interfere with the expression of SENP3 gene in the animal and in vitro cultured cells to explore the regulatory mechanism of SENP3 /PML de-SUMO in the neurogenesis, neural differentiation and neural migration of hippocampal DG neurons. It will also provide news ideas and methods for early prevention and treatment of learning and memory impairment in infants under sevoflurane anesthesia.

麻醉药物对婴幼儿发育的影响一直是麻醉学关注的焦点，海马神经发生在调节学习记忆过程中起着至关重要的作用，但其分子调控机制，尤其蛋白质翻译后修饰尚待深入探讨。研究表明，早幼粒细胞白血病蛋白（PML）SUMO化参与神经干细胞分化和迁移，与发育期脑神经发生密切相关。我们前期研究发现七氟醚多次暴露下新生小鼠海马新生神经元数量减少，神经元迁移抑制蛋白Slit2和SUMO化特异性蛋白酶SENP3表达增加，因此我们假设七氟醚通过增加SENP3介导PML去SUMO化，激活Slit2信号通路，诱导神经元发生障碍和迁移异常,引起学习记忆减退。本项目通过选择性SENP3基因敲除和构建SENP3基因低表达或高表达载体，干预体内和体外麻醉模型，采用分子生物学、免疫荧光等技术探讨SENP3介导PML去SUMO化在海马DG区神经元发生、分化和迁移中的调控机制，为七氟醚麻醉下婴幼儿学习记忆减退的早期防治提供新靶点和新策略。

麻醉药物对婴幼儿发育的影响一直是麻醉学关注的焦点，海马神经发生在调节学习记忆过程中起着至关重要的作用。早幼粒细胞白血病蛋白（PML）的SUMO化参与了神经干细胞分化和迁移，可能与七氟醚致发育期大脑远期学习记忆功能损害有关。本实验通过建立刚出生小鼠多次长时间七氟醚麻醉模型，证实七氟醚多次长时间麻醉, 海马DG区SENP3蛋白表达增加、SUMO2/3蛋白表达减少，PML蛋白SUMO化减少，海马DG区新生神经元减少，小鼠远期学习记忆功能损伤。另外，我们通过AAV9包装SENP3 siRNA，减少海马DG区SENP3表达，通过动物和细胞模型证实了PML蛋白SUMO化参与了七氟醚多次长时间麻醉后小鼠DG区神经元的发生、分化和迁移。PML蛋白有多种亚型，在不同的组织中或者处于不同时相的细胞中，PML所形成的亚型不同。因此本研究为进一步探索PML不同亚型在海马DG区神经发生过程中的作用奠定了坚实的工作基础。本项目资助发表SCI论文2篇，待发表2篇。