雪旺细胞-藻酸钠凝胶移植促进脊髓损伤修复的实验研究

Experimental study of Schwann cells-alginic acid sodium hydrogel transplantation promoting spinal cord injury restore

目的:观察雪旺细胞-海藻酸钠凝胶移植对大鼠脊髓损伤后脊髓细胞凋亡、Bc l-2及功能恢复的影响,探讨其对脊髓损伤修复的促进作用机制。方法:选择清洁级SD大鼠120只,按随机数字表法分为4组:正常对照组、单纯损伤组、雪旺细胞组、雪旺细胞-海藻酸钠凝胶组,每组30只大鼠。制作T10节段脊髓全横断损伤模型。分别于12 h、24 h、3 d、7 d、21 d等5个时间段对动物进行BBB评分后处死。取损伤区1 cm范围脊髓节段,常规石蜡包埋,水平切片进行TUNEL、Bc l-2染色,观察脊髓内凋亡细胞、Bc l-2细胞的数量及分布变化。按BBB评分法对大鼠术后运动功能的恢复情况进行评分。结果:正常对照组仅有少量淡染Bel-2阳性细胞;损伤对照组神经元Bc l-2免疫反应阳性细胞表达的高峰在第3和第14天时Bc l-2免疫反应阳性细胞表达接近正常水平。雪旺细胞-海藻酸钠凝胶移植后损伤脊髓细胞Bc l-2免疫反应阳性细胞表达具有显著增高(P<0.05),7 d高度表达并持续2周以上。单纯损伤组脊髓内细胞凋亡最多,并于损伤后第1和第7天形成两个高峰,多分布于白质中。雪旺细胞-海藻酸钠凝胶组细胞凋亡数量较单纯损伤组,差异有统计学意义(P<0.05)。雪旺细胞-海藻酸钠凝胶组BBB评分较单纯损伤组及雪旺细胞组明显提高,差异有统计学意义(P<0.05)。结论:雪旺细胞-海藻酸钠凝胶移植能抑制大鼠脊髓损伤后脊髓细胞凋亡、促进Bel-2的表达以及脊髓的功能恢复。

OBJECTIVE： To observe the effects of Sehwann cells-alginic acid sodium hydrogel transplantation on cells apoptosis, Bcl-2 and function recovery on spinal cord injury rats, and explore its promoting mechanism during the period of recovery of SCI. rats. Methods： 120 cases of cleaning SD rats were divided into 4 groups by random digits table： normal control group, injury control group, Sehwann cells group and Sehwann cells-alginic acid sodium hydrogel group, with 30 rats in each. The experimental injury models of rats were made by transeeted SCI at the T10 level. Rats were sacrificed at 12h and 1,3,7,21 clays after injury, a 1-cm cord segment centered at the lesion site was removed and embedded in paraffin, cross-section were cut and stained with the methods of TUNEL and Bcl-2 immunohistoehemistry, in order to observe the number and distribution of apoptosis and Bcl-2 cells. BBB score was designed to assess the behavior ability of rats after operation. Results： There were only few weak stain positive Bcl-2 cells. Meanwhile, Bcl-2 protein expression in spinal cord of SCI rats were increased markedly after the Schwann cell-Alginic Acid Sodium hydrogel （SC-AH） were transplanted（ P 〈 0. 05 ）, the grafted group reached its peak 7 d after SCI and maintains its high level until 2 weeks later, however, the Bcl-2 expression of injury control group decreased dramatically 3d after injury,and it＇s level of Bcl-2 positive ceils approach to normal control. There were maximum Bcl-2 positive cells in injury control group, and formed two peaks after ld, 3d after injury operation. The majority of Bcl-2 cells distribute in the gray matter of SCI spinal cord. The Bcl-2 positive cells number was significantly lower in SC-AH group than injury control group （P 〈 0.05）. Conclusion： Schwann cell-Alginic Acid Sodium hydrogel （SC-AH） transplantion could inhibit the apoptosis, promote expression of Bcl-2 and improve the functional recovery of rats spinal cord.