Slit2通过抑制神经炎症改善生发基质出血后脑积水的机制研究

Neonatal cerebral hemorrhage is a disease that endangers neonatal survival. Posthemorrhagic hydrocephalus (PHH) is an important pathophysiological process that aggravates neonatal brain injury, and the mechanism unclear. Studies have shown that one key mechanism of PHH is neuroinflammatory response after intracerebral hemorrhage induces peripheral immune cell infiltration and blocks cerebrospinal fluid circulation. In study of newborn rat PHH model, we found leukocyte chemotactic inhibitor Slit2 involved in the occurrence of PHH, but it's mechanism needs to further investigated. Combining with the research progress in the field of neonatal PHH and the basis of preliminary experiments, we conclude that Slit2 is involved in the regulation of PHH by activating the Robo1/srGAP1/Cdc42 signal axis to inhibit the neural inflammatory response. In the present study, gene silencing and other methods are used in the germinal matrix hemorrhage (GMH) -PHH model of newborn rats to explore the role of Slit2 in the development of PHH and its molecular mechanism, and to clarify its signal transduction mechanism, and to explore a new perspective for the prevention and treatment of neonatal PHH.

新生儿脑出血是危害新生儿存活和神经系统预后的严重疾病，出血后脑积水（PHH）是加重新生儿脑损伤的重要病理生理过程，机制尚不完全清楚。研究发现，脑出血后神经炎症反应募集外周免疫细胞浸润，阻塞脑脊液循环是PHH发生的主要机制。我们在新生大鼠PHH模型研究中发现白细胞趋化抑制因子Slit2参与PHH的发生，但信号转导机制仍不清楚。结合新生儿PHH领域研究进展和预实验基础，我们提出Slit2通过激活Robo1/srGAP1/Cdc42信号轴抑制神经炎症反应参与调节PHH的发生的科学假设。本研究将在新生大鼠生发基质出血（GMH）－PHH模型中通过基因沉默等方法，探讨Slit2在PHH发生发展的作用及其分子机制，明确其信号转导机制，为新生儿PHH的预防和治疗发掘新视角。

本项目通过细菌胶原酶定向注入生发基质，建立脑出血的大鼠模型。实验分析证明，内源性Slit2敲除加重了脑出血后的脑水肿和短期神经功能缺损，而外源性Slit2重组蛋白能降低脑出血后的促炎细胞因子和细胞间黏附分子表达、脑内的外周免疫细胞标志物、Cdc42活性以及神经功能缺损。同时，给予重组Robo1和srGAP1 siRNA可逆转上述作用。本项目通过一些列的实验研究Slit2对脑出血后大脑神经功能的积极调控作用和相关分子通路，揭示脑出血后神经损伤及修复的机制，阐明Slit2通过Robo1-srGAP1介导的Cdc42活性抑制阻止外周免疫细胞浸润，从而抑制神经炎症，改善大鼠脑出血后的神经功能损伤。同时还阐明Slit2是白细胞趋化的抑制剂，为出血诱导的涉及白细胞迁移和趋化因子的神经炎症提供了一种新的治疗方法。