给予姜黄素结合移植脐带间充质干细胞抑制大鼠脊髓胶质瘢痕的机制研究

hUC-MSCs(human umbilical cord-derived mesenchymal stem cells) with a abundant source was found to enhance the injured spinal cord funtcion of rats by secreting neurotrophins and increase neural fiber mildly,decrease the formation of glial scar partly. We also found that curcumin protect injured spinal cord by decreasing pro-inflammatory factor and formation of glial scar.The new strategy of spinal cord repair is to make grafted cell differentiate into neuron which take part in neural pathway,the neurite regrowth must get over the obstacle of glial scar.It is presumed that curcumin promote hUC-MSCs differentiate into more neuron and less glial cell owing to its intensive regulating effect of histone acetylation. So the experiment is designed to prove curcumin cooperating with hUC-MSCs may decrease glial scar and make clear likely JAK/STAT and Wnt/β-catenin signal pathway through modification effect of histone acetylation by histology, immunofluorescence, CHIP，RNA interference, neural tracing etc. it may provide experimental evidence for favor of neurogenesis and glial scar decreasing and recovery of injuried spinal cord following cell transplantation.

前期研究发现具有丰富来源的人脐带间充质干细胞（hUC-MSCs）促进大鼠损伤脊髓功能恢复主要通过分泌神经营养因子起作用，而新生神经纤维少量增加，胶质瘢痕部分抑制。还发现姜黄素拮抗脊髓损伤后前炎症因子作用保护脊髓，并减轻胶质瘢痕形成。促使移植细胞分化参与神经通路构成是脊髓修复的新策略，须克服胶质瘢痕的阻碍。姜黄素具有强烈调节组蛋白乙酰化功能，组蛋白乙酰化在各种干细胞增殖分化中起重要作用。推测姜黄素可能通过该作用，促进hUC-MSCs向胶质细胞分化少，向神经细胞分化多。拟经过体外实验，结合损伤立即给予姜黄素并1周后的hUC-MSCs移植，利用组织学、免疫荧光、染色体沉淀、RNA干扰、神经束路追踪等技术，证明两者协同显著抑制胶质瘢痕；进一步阐明姜黄素的组蛋白乙酰化修饰可能的JAK/STAT和Wnt/β-catenin信号传导途径；从而为促进损伤脊髓功能的明显恢复提供实验依据。

脊髓损伤导致运动感觉等神经功能严重损害，目前针对脊髓损伤的治疗仍缺乏有效措施。本研究使用姜黄素离体干预人脐带间充质干细胞（hUC-MSCs），发现姜黄素可以促进hUC-MSCs表达神经元的标记物Neuron及Tuj1。体内的研究显示姜黄素联合hUC-MSCs可以更有效的抑制胶质瘢痕及脊髓空洞的形成，促进脊髓损伤后大鼠后肢功能的恢复；还发现联合使用姜黄素后远期存活的hUC-MSCs明显增加，但未检测到移植的的hUC-MSCs分化为神经元或星型胶质细胞，提示姜黄素可能是通过抑制凋亡与hUC-MSCs发挥协同治疗作用。体外研究显示姜黄素通过激活ERK，促进促细胞存活相关蛋白Bad磷酸化，发挥抑制TNF-α诱导hUC-MSCs凋亡的作用。体内进一步证实阻断ERK的激活后，移植早期hUC-MSCs凋亡的比例较阻断前增加，同时远期存活的hUC-MSCs较阻断前减少；并且U0126阻断ERK的激活后部分降了姜黄素结合hUC-MSCs对脊髓损伤的治疗效果。提示姜黄素可以通过激活ERK，促进Bad磷酸化与hUC-MSCs协同抑制脊髓损伤后胶质瘢痕的形成，促大鼠神经功能的恢复。