EphB4/EphrinB2调节骨髓间充质干细胞移植治疗脑性瘫痪的归巢机制研究

The research for the treatment of cerebral palsy has been a hotspot and difficult problem in the scientific research and clinical institutions of the world. Stem cell therapy as a new treatment of nervous system diseases has become a focus of attention in the medical field and abroad such as stroke, spinal cord injury and Parkinson's disease. Bone marrow mesenchymal stem cell transplantation in the treatment of cerebral palsy in clinical application, there are still many bottlenecks, such as cell transplantation inefficient homing etc. BMSCs as a source of mesenchymal stem cells can differentiate into neurons under certain conditions. EphB4/EphrinB2 forward and reverse signal transduction pathways regulating stem cell migration play a specific biological effect. This study will determine the neuroprotective effect of stem cell transplantation in rats with cerebral palsy,by transfection of EphrinB2 to BMSCs stereotactic method stem cell transplantation, through pathology imaging and molecular biology techniques and analyze EphB4/ephrinB2 forward signaling pathways regulation of VLA-4 / VCAM-1 axis and reverse signaling pathway inhibition of SDF-1 / CXCR4 axis from both in vivo and in vitro in BMSCs transplantation in rats with cerebral palsy,thus explore the mechanisms of the EphB4/ephrinB2 signaling pathway in BMSCs transplantation homing for the treatment of cerebral palsy and establish theoretical basis for the transformation of stem cells in clinical therapy of cerebral palsy.

脑瘫患儿的治疗方法的深入探索已成为国际科研与临床机构研究热点和难点。干细胞移植作为一种新的神经系统疾病治疗手段已成为国内外医学领域关注焦点。骨髓间充质干细胞 (Bone marrow mesenchymal stem cell,BMSCs)移植治疗脑瘫临床应用尚存在多方面瓶颈,如归巢效率低下等。 BMSCs在特定条件下能分化为神经元细胞。EphB4/EphrinB2 正向及反向信号传导通路调控干细胞定向迁移，发挥特定生物学效应。本研究拟通过转染 EphrinB2大鼠BMSCs干细胞移植脑瘫，通过分子生物学病理学等技术确定干细胞移植对脑瘫大鼠的保护作用并从体内和体外两个方面分析EphB4/ephrinB2正向信号通路调控VLA-4 /VCAM-1轴及反向信号通路抑制SDF-1 /CXCR4轴,进一步探讨其信号通路在BMSCs移植治疗脑瘫归巢机制，为干细胞治疗脑瘫临床转化奠定理论基础。

小儿脑性瘫痪是导致儿童残障的主要疾病,目前对小儿脑瘫的治疗缺乏特效治疗。近年来干细胞移植作为脑性瘫痪一种新的治疗手段已成为神经科学领域关注的焦点。骨髓间充质干细胞(Bone marrow mesenchymal stem cell,BMSCs)移植治疗脑瘫临床应用尚存在多方面瓶颈,如归巢效率低下等。本研究拟通过转染ephrin2BMSCs立体定向法干细胞移植，通过分子生物学病理学等技术从体内外实验证实干细胞移植对脑瘫大鼠的保护作用及EphB4/EphrinB2双向信号通路在诱导移植的骨髓间充质干细胞向脑性瘫痪损伤脑组织的定向迁移中的作用。说明了EphB4/ephrinB2双向信号通路对诱导移植的骨髓间充质干细胞向脑性瘫痪损伤脑组织的调控及机制。主要研究结果如下：（1）在体外携带有EphrinB2可以被有效转染到BMSCs，分化成神经元样细胞，促进细胞迁移，该效应是EphB4/ephrinB2信号通路通过调控Grb4引起ERK/JNK/C-jun信号通路激活；（2）慢病毒介导EphrinB2转染 BMSCs 移植到侧脑室后海马可以高效表达EphrinB2基因，促进神经元细胞分化和血管新生，并干细胞归巢到脑部损伤的海马和皮层，抑制细胞凋亡，在神经修复过程中起到了一定的作用；（3）进一步采用高通量蛋基因芯片技术，研究了EphrinB2对脑瘫大鼠脑组织基因芯片的影响并进行验证，试图寻找可能参与EphrinB2发挥保护作用的相关分子蛋白，结果发现基因分析表明主要影响Ephrin家族、细胞迁移、调节细胞凋亡等通路，q-PCR证实EphB4/ EphrinB2反向信号通路VEGF、Grb4、ABI、STAT3、FAK mRNA水平表达增高。综上所述，EphB4/ EphrinB2通过调控干细胞的定向迁移，促进血管分化，抑制细胞凋亡中发挥在诱导移植的骨髓间充质干细胞脑性瘫痪损伤脑组织的保护作用。本研究为干细胞的转化医学研究提供了一定的理论依据。