骨髓间充质干细胞外泌体通过miR-382-3p/HMGB1通路调控糖尿病脑出血后神经炎症的机制研究

Neuroinflammation is an important mechanism affecting the recovery of cerebral nerve function and prognosis of patients after diabetic intracerebral hemorrhage. However, the specific molecular mechanism and control mode are not completely clear. HMGB1 is a vital pro-inflammatory warning factor after stroke. In our previous studies, we used mRNA chip screening,combined with qPCR,western blot and other experimental methods. It was found that the expression of HMGB1 and its receptor TLR4 significantly increased in brain tissue after diabetes mellitus and intracerebral hemorrhage, and there was a targeted regulatory relationship between miR-382-3p and HMGB1 by bioinformatics analysis. Recent studies have found that mesenchymal stem cells can participate in the occurrence and development of a variety of diseases through the exosomes.Based on the related references, we hypothesize that exosomes derived from bone marrow mesenchymal stem cells may regulate neuroinflammation through mir-382-3p/HMGB1 pathway after diabetic intracerebral hemorrhage. We will use gene knock-out mice, combined with a variety of molecular biological techniques to elucidate the role and mechanism of bone marrow mesenchymal stem cells after diabetic intracerebral hemorrhage in an all-round and multi-level manner. And this study will provide a new therapeutic target and theoretical basis for the recovery of neurologic function after diabetic intracerebral hemorrhage.

神经炎症是影响糖尿病脑出血后大脑神经功能恢复以及患者预后的重要反应机制，然而具体的分子机制以及控制方式尚不完全清楚。HMGB1是脑卒中后一种至关重要的促炎警报因子，在前期研究中我们利用mRNA芯片筛选，结合qPCR、western blot等实验方法，发现糖尿病及脑出血后脑组织中HMGB1及其受体TLR4表达含量明显增加，并通过生物信息学分析发现miR-382-3p与HMGB1存在靶向调控关系。在近期研究发现间充质干细胞可通过外泌体转移功能因子参与多种疾病的发生与发展。结合相关文献报道，我们提出如下假设：骨髓间充质干细胞外泌体通过miR-382-3p/HMGB1通路调控糖尿病脑出血后神经炎症。本项目将利用基因敲除鼠，多种分子生物学技术，在体内、体外，全方位、多层次的验证骨髓间充质干细胞在糖尿病脑出血后作用及机制，为糖尿病脑出血后的神经功能恢复提供新的靶向治疗位点及理论依据。

背景及目的：糖尿病作为脑卒中患者的高危因素，会引起机体内的氧化应激和炎症反应，而炎症反应作为脑出血后引起脑组织继发性损伤的主要机制会加重脑的损伤。在脑出血后骨髓间充质干细胞外泌体可以被神经元、星型胶质细胞及小胶质细胞吸收，从而促进神经功能的恢复。目前骨髓间充质干细胞外泌体在糖尿病脑出血中的作用尚没有深入的研究，因此，本研究旨在探究间充质干细胞外泌体减轻糖尿病脑出血后神经炎症的机制。结论：1.骨髓间充质干细胞外泌体能够减轻糖尿病脑出血后的神经炎症反应。2.骨髓间充质干细胞外泌体装载的miR-129-5p可通过抑制HMGB1蛋白的表达减轻神经炎症及神经功能损伤。3.miR-129-5p可以作为减轻糖尿病脑出血继发的神经炎症、改善大脑损伤的新靶点。意义：使用生物信息学、细胞生物学和分子生物学方法研究MSC-Exos在体内和体外神经炎症中的作用。结果显示，高血糖会增加ICH小鼠或BV2细胞的炎症，给予表达miR-129-5p的MSC-Exos成功抑制了HMGB1信号通路，并抑制了体内和体外的炎症反应。减少DM/ICH后的炎症反应，脑内神经功能得到改善，这一结果是通过miR-129-5p/HMGB1/TLR4调节轴实现的。综上所述，本研究结果为糖尿病脑内出血后神经功能的恢复提供了理论依据，并可能为神经炎症的靶向治疗提供一种新方法。