神经干细胞联合胶原蛋白支架移植脊髓损伤大鼠脑细胞的凋亡

背景：目前的研究表明，从胚胎大鼠大脑皮质分离的神经干细胞在胶原蛋白凝胶中可增殖并分化为神经元、星形胶质细胞和少突胶质细胞。 目的：观察神经干细胞联合胶原蛋白支架移植对脊髓损伤后鼠大脑神经细胞凋亡的影响。 方法：取45只SD大鼠制作脊髓半切损伤模型，随机分为3组，造模1周后，细胞移植组大鼠运动皮质后部在脊髓损伤部位注入同种异体神经干细胞悬液，联合组在脊髓损伤部位注入同种异体神经干细胞结合胶原蛋白悬液，模型组不植入任何物质。 结果与结论：移植后1-8周，3组大鼠肢体运动功能均有不同程度恢复，且联合组移植后8周BBB运动评分明显高于其他两组（P 〈 0.05）。移植后1周苏木精-伊红染色显示3组均可见少量凋亡细胞及Bcl-2抗凋亡蛋白阳性细胞，大量Bax阳性细胞；随时间的推移，3组Bax凋亡蛋白阳性细胞、Bcl-2抗凋亡蛋白阳性细胞逐渐减少，并且移植后8周联合组、细胞移植组Bax阳性细胞明显低于模型组（P 〈 0.05），Bcl-2抗凋亡蛋白阳性细胞高于模型组（P 〈 0.05），此时3组均无凋亡细胞。表明神经干细胞联合胶原蛋白支架移植可抑制脊髓损伤后鼠大脑神经细胞的凋亡，促进脊髓神经功能的恢复。

Effect of combination of neural stem cells transplantation and collagen gel scaffold on apoptosis of brain cells in rats after spinal cord injury

BACKGROUND： Studies have shown that neural stem cells isolated from embryonic rat cerebral cortex can proliferate and differentiate into neurons, astrocytes and oligodendrocytes in collagen gels.
OBJECTIVE： To investigate the effect of neural stem cells combined with collagen gel on the apoptosis of nerve cells in the brain of rats after spinal cord injury.
METHODS： Forty-five spinal cord injury rat models were made through spinal cord hemisection and randomly divided into three groups. At 1 week after modeling, rats in the cell transplantation group were injected allogeneic neural stem cell suspension into the injured site, rats in the combination group were administered with allogeneic neural stem cells/collagen gel suspension into the injured site, and rats in the model group received no treatment.
RESULTS AND CONCLUSION： From 1 to 8 weeks after injury, the Basso, Beattie and Bresnahan （BBB） locomotion scores in the combination group were significantly higher than those in the other two groups （P 〈 0.05）. Hematoxylin-eosin staining showed that at 1 week after transplantation, there were a few necrotic cells and Bcl-2 positive cells, but a large amount of Bax positive cells in the three groups. Then, the number of Bax- and Bcl-2-positive cells was reduced graduallyin the three groups. At 8 weeks after transplantation, the number of Bax-positive cells was significantly higher in the model group than the other two group （P 〈 0.05）, but the number of Bcl-2-positive cells were dramatically lower （P 〈 0.05）. Meanwhile, there were no necrotic cells in the three groups. These findings indicate that neural stem cell transplantation combined with collagen gel scaffold can arrest apoptosis of nerve cells in the brain of rats after spinal cord injury, and promote functional recovery after spinal cord injury.