基于Nrf2/CXCR4途径研究川芎嗪促神经干细胞迁移作用及机制

Stromal cell-derived factor 1 (SDF-1) /CXCR4 pathway has been well demonstrated to direct NPC cell trafficking, and the role of Nrf2 in the stem cells migration and in the treatment of stroke has attracted increasing attention. Tetramethylpyrazine (TMP) originally isolated from Ligusticum walliichi (Chuanxiong), has been widely applied in the treatment of occlusive cerebrovascular disease. Previous study reported that the action of TMP in neuroprotection is related to the activation of Nrf2, but its mechanism remains largely unknown. Interestingly, our preliminary study suggested that TMP can promote the migration of NSCs. Hence we propose a hypothesis that TMP can promote the migration of NSCs via Nrf2/CXCR4 pathway. In this project, the effect of TMP on the endogenous and exogenous NSCs to migrate to the ischemic area was observed firstly by the middle cerebral artery occlusion (MCAO) model on rats. Secondly, the mechanism of TMP on the migration of NSCs in cytology and molecules were explored by using a variety of technology, such as cell migration model in vitro, gene chip, gene silencing, high throughput screening. Finally, the migration of NSCs was investigated in vivo and in vitro by using pharmacological inhibitors for these signaling pathways such as Nrf2/CXCR4 pathway. This study will provide some experimental support for the application of TMP in stroke clinically; also provide hints for a new therapeutic mode by combination of TMP with stem cell transplantation.

SDF-1/CXCR4是调控神经干细胞（NSCs）迁移的主要通路，Nrf2对干细胞迁移及其在脑中风治疗机制研究中的作用日益引起关注。川芎嗪(TMP)是来自川芎已被临床广泛应用于治疗闭塞性脑血管疾病的单体成分，研究显示其脑保护作用与活化Nrf2有关，但具体机制不明。我们基于前期TMP可促进NSCs迁移的研究基础，提出了“TMP通过Nrf2/CXCR4途径促进NSCs迁移治疗脑中风”的假说。本项目首先通过大脑中动脉栓塞(MCAO)大鼠模型，观察TMP对内源性和外源移植性NSCs向缺血区迁移的影响；其次借助多种细胞迁移模型、基因芯片以及高内涵筛选等技术，探索TMP促进NSCs迁移的细胞学及分子机制；最后通过抑制主要靶点（如Nrf2/CXCR4途径），在体内外迁移模型上反向印证。本研究将为TMP临床合理应用提供实验支持，也为TMP作为干细胞移植联合用药的新治疗模式提供线索。

神经再生在脑卒中等神经损伤性疾病的病程及治疗中发挥重要作用，展现出良好的应用前景。SDF-1/CXCR4是调控神经干细胞（NSCs）迁移的主要通路，最新研究报道Nrf2对干细胞迁移及其在脑中风治疗机制研究中的作用日益引起关注。川芎嗪(TMP)在临床广泛应用于治疗闭塞性脑血管疾病，研究显示其脑保护作用与活化Nrf2有关，但具体机制不明。我们基于前期TMP可促进NSCs迁移的研究基础，提出了“TMP通过Nrf2/CXCR4途径促进NSCs迁移治疗脑中风”的假说。本项目首先通过大脑中动脉栓塞(MCAO)大鼠模型，明确了TMP单独以及联合NSCs移植均可显著改善脑缺血大鼠的行为学损伤；其次TMP还可以显著促进内源性和外源移植性NSCs向缺血区的迁移；再者借助多种细胞迁移模型、基因芯片、分子生物学技术，结果发现TMP促进NSCs迁移的细胞学及分子机制，与激活Nrf2/CXCR4途径有关；最后通过抑制主要靶点（如Nrf2/CXCR4途径），在体内外迁移模型上反向印证，结果发现抑制Nrf2/CXCR4通路上的关键靶点后，TMP促进NSCs迁移的作用被显著消弱。本研究将为TMP临床合理应用提供实验支持，也为TMP作为干细胞移植联合用药的新治疗模式提供线索。