骨髓间充质干细胞NgR基因沉默静脉移植治疗大鼠脑损伤

Treatment of Traumatic Brain Injury in Rats by Intravenous Transplantation of BMSCs with NgR Gene Silencing

目的:探讨沉默NgR基因的方法对骨髓间充质干细胞(BMSC)静脉移植治疗大鼠脑损伤效果的影响。方法:体外培养BMSC,经小分子干扰RNA(siRNA)转染以沉默NgR基因表达,用Westernblot法检测BMSC在转染前后NgR基因蛋白的表达。60只SD大鼠制成大鼠重型液压颅脑损伤模型,随机分为3组。A组20只给予NgR基因沉默的BMSC;B组20只给予等量的BMSC悬液;C组20只注射等量的不含干细胞的培养液。对各组静脉移植分别于处理后1d、3d、伤后1周及2周行Bederson评分并评价大鼠神经功能的损伤情况,2周后处死行NF、BrdU免疫组化和HE染色。结果:转染siRNA后,A、B组NgR基因蛋白表达量较C组明显降低,移植后1周大鼠神经学缺损评分A组<B组<C组(均P<0.05);2周后其脑组织中的NF阳性纤维数A组>B组>C组(均P<0.05),BrdU阳性细胞数A组>B组(P<0.05),C组中未检出。结论:BMSC的沉默NgR基因静脉移植治疗大鼠脑损伤可明显改善大鼠的神经学功能。

Objective：To determine whether the NgR gene silencing can enhance curative effects of intravenous transplantation of bone marrow derived stroma cells （BMSCs） on traumatic brain injury （TBI） in rats. Methods：BMSCs were cultured by the suspension culture in vitro, and were transfected by siRNA to knock down the expression of NgR. Western blot was used to assess the knockdown efficiency. The models of severe TBI were made in rats by giving 2.5-3.0 atm power of hydraulic impact. Sixty SD rats were randomly divided into three groups, group A was injected the NgR gene silencing of BMSCs, group B for the equivalent of BMSCs suspension and group C was injected the same amount of non-stem cell of the culture medium. The neurological defect scores were determined after 1 d, 3 d,7 d and 14 d after TBI. Rats were sacrificed after 2 weeks to perform the immunohistochemistry and HE staining. Results：Western blot results approved that the expression of NgR was knocked down 24 h after transfection of siRNA. The neurological defect scores were significantly lower in group A than those in group B and C 1 week after TBI （P 0.05）. The number of neurons was higher in group A than that in group B and C （P 0.05）. Conclusion： The BMSCs of NgR gene silencing transplanted by vein into the traumatic brain tissues can significantly improve the neurological function in rats with TBI.