脂肪间充质干细胞治疗外伤性脑损伤

Adipose mesenchymal stem cells for treatment of traumatic brain injury

背景:临床与动物研究证实,间充质干细胞移植能迁移至脑损伤区域,对创伤性脑损伤有一定的治疗效果。目的:进一步验证脂肪间充质干细胞对大鼠外伤性脑损伤造成的局部损伤的治疗作用。方法:大鼠随机分为3组:实验组和对照组参照文献以脑冷冻伤法制作SD大鼠脑损伤模型,实验组造模成功2 d后进行脂肪间充质干细胞尾静脉移植;对照组只尾静脉注射等量生理盐;正常组大鼠不作任何处理。采用Morris水迷宫测试评价大鼠神经功能恢复情况;体个分离、培养脂肪间充质干细胞,在倒置显微镜下观察脂肪间充质干细胞的形态,免疫组织化学检测干细胞在大鼠损伤脑组织中的分布及脑源性神经营养因子和胶质细胞源性神经营养因子含量。结果与结论:(1)Morris水迷宫测试结果显示:与对照组比,实验组SD大鼠平均逃避潜伏期迅速下降(P<0.05),而同时实验组大鼠逃避潜伏期越来越接近于正常组大鼠;(2)免疫组织化学后倒置显微镜观察:移植的经Brdu标记的脂肪间充质干细胞大量聚集在损伤的大脑皮质,呈不均匀分布。而对照组大鼠脑组织内未见Brd U免疫荧光显色;(3)Western-blot检测结果显示:实验组经脂肪干细胞静脉移植后,SD大鼠海马区域中的脑源性神经营养因子和周围损伤皮质中的胶质细胞源性神经营养因子的含量明显高于对照组(P<0.05)。而与正常组SD大鼠比较,对照组大鼠脑组织中海马区域中的脑源性神经营养因子含量升高(P<0.05),而皮质周围的胶质细胞源性神经营养因子含量却明显下降(P<0.05);(4)实验结果提示移植的脂肪间充质干细胞向大鼠脑组织的损伤部位分布,并促进了受损脑组织的胶质细胞源性神经营养因子和脑源性神经营养因子分泌,这也可能是对大鼠神经功能恢复的治疗促进作用之一。

BACKGROUND： Clinical and animal studies have confirmed that transplanted mesenchymal stem cells can migrate to the area of brain injury, and exert a certain therapeutic effect on traumatic brain injury. OBJECTIVE： To study the therapeutic effect of adipose mesenchymal stem cells on the local damage induced by traumatic brain injury in rats. METHODS： According to the literatures, the brain injury model of Sprague-Dawley rats was made by brain freezing injury. After successful modeling, the rats were randomly divided into three groups： model rats in experimental group were administrated with transplantation of adipose mesenchymal stem cells via the tail vein at 2 days after modeling; model rats in control group given the same amount of normal saline; and normal rats in normal group given no treatment. Morris water maze test was used to evaluate the recovery of neurological function in rats. The isolated and cultured adipose mesenchymal stem cells were observed under an inverted microscope. The distribution of these cells in the injured brain and the levels of brain-derived neurotrophic factor （BDNF） and glial cell line-derived neurotrophic factor （GDNF） were detected by immunohistochemistry method. RESULTS AND CONCLUSION： Morris water maze test results showed that compared with the control group, the average escape latency of rats decreased rapidly in the experimental group, and the difference was statistically significant （P 〈 0.05）, while the escape latency of rats in the experimental group was gradually close to that in the control group. Immunohistochemical findings showed that Brdu-labeled adipose mesenchymal stem cells were accumulated and distributed unevenly in the injured cerebral cortex. In the control group, there was no BrdU immunofluorescence staining in the rat brain tissues. Western blot test results showed that： compared with the control group, the BDNF and GDNF levels in the hippocampus of rats were significantly higher in the experimental group （P 〈 0.05）, but compared with the normal group, the BDNF level in the hippocampus of rats was significantly increased, and the GDNF level in the cortex decreased significantly in the control group （P 〈 0.05）. These findings indicate that adipose mesenchymal stem cells can migrate to the damaged area of rats, and promote the secretion of BDNF and GDNF in the injured brain, which may be one of the mechanisms by which adipose mesenchymal stem cell transplantation improves neurological functional recovery of rats.