脂肪间充质干细胞治疗脑瘫大鼠的作用机理研究

The therapeutic mechanism of adipose mesenchymal stem cells on cerebral palsy induced by pyramidal tract injury in rats

目的探讨Notch信号通路在脂肪间充质干细胞治疗锥体束损伤所致脑瘫大鼠中的作用机理。方法利用脑立体定位技术在大鼠锥体束注射乙醇构建脑瘫大鼠,通过尾静脉注射大鼠脂肪间充质干细胞,通过悬吊实验、旷场实验、姿势异常、肌张力、步态活动进行脑瘫行为学评估;取大鼠锥体束注射部位的脑组织做病理组织切片进行组织病理学分析,取锥体束注射部位脑组织进行荧光定量PCR检测Notch信号通路相关基因timp1、collagen1、hes1、hey1、jag1、notch1的表达。结果与模型组比,干细胞治疗组大鼠玻璃棒悬吊时间明显增长,差异显著;姿势异常、肌张力及步行姿态得到明显改善且差异显著;组织病理学分析证实脑瘫模型组大鼠脑组织纤维束增多,而脂肪间充质干细胞治疗组纤维束明显少;脂肪间充质干细胞治疗组神经细胞数量约为脑瘫模型组的2倍,大脑神经细胞再生非常明显,脑神经细胞形态及脑组织结构破坏较脑瘫组有所改善;与模型组比,干细胞治疗组jag1、timp1、collagen1和hes1基因表达水平显著降低,hey1基因表达水平明显升高。结论脂肪间充质干细胞能够通过调控Notch信号通路促进脑瘫大鼠脑神经修复,改善脑瘫大鼠的运动功能。

Objective The purpose of this study was to investigate the mechanism of adipose mesenchymal stem cells treatment on cerebral palsy induced by the injury of the vertebral tract in rats.Methods Cerebral palsy rats were established by injecting ethanol into the pyramidal tract of rats with stereotaxic technique.Rat adipose mesenchymal stem cells were injected through the tail vein.Suspension test,open field test,postural abnormalities,muscle toneand gait activity were evaluated on day6th after stem cells injection.The brain tissues at the ethanol injection site of the pyramidal tract of rats were collected for histopathological analysis.The brain tissues at the injection site of the pyramidal tract were collected to detect the expressions of Notch signaling pathway-related genes,including timp1、collagen1、hes1、hey1、jag1 and Notch1.Results Compared with model group,the suspension time of glass rod in stem cell treatment group rats were significantly increased,and the difference was significant in abnormal posture,muscle tension score and walking posture.Histopathological analysis confirmed that the number of fiber tracts in cerebral tissue of rats in the cerebral palsy model group was increased,while basically undetectable in the adipose mesenchymal stem cell treatment group.The nerve cells in the adipose mesenchymal stem cell treatment group was about two times than the cerebral palsy model group,which indicates a higher regeneration potency.Consistently,the brain nerve cell morphology and brain tissue structure of stem cell treatment group was improved compared with the cerebral palsy model group.Compared with the model group rats,the expressions of jag1,timp1,collagen1 and hes1 in the treatment group was significantly decreased,while the expression of hey1 gene was significantly increased.Conclusion Adipose mesenchymal stem cells promote cerebral nerve repair and improve motor function of cerebral palsy rats through Notch signaling pathway.