背景：骨髓基质干细胞可分化为神经细胞，能促进神经组织修复，但具体机制还未完全阐明。 目的：探讨β神经生长因子重组腺病毒转染骨髓基质干细胞移植对颅脑损伤的保护作用机制。 方法：①利用β神经生长因子重组腺病毒载体系统转染体外培养的大鼠骨髓基质干细胞，然后用β-巯基乙醇对骨髓基质干细胞进行定向诱导分化；②选取210只SD大鼠，随机分为5组：诱导转染骨髓基质干细胞组、诱导未转染骨髓基质干细胞组、诱导剂+培养基组、颅脑损伤组、假手术组，每组42只。制备颅脑损伤模型，按照不同时间点(12，24，36，48，72 h)进行相应的移植物治疗，分别于移植当天，移植1，2，3，4周采用NSS评分法进行神经功能评分；③选取75只SD大鼠，同上随机分为5组，每组15只。颅脑损伤模型制备24 h后进行相应的移植物治疗。移植当天，移植1，2，3，4周对各组动物进行NSS 评分。移植当天，移植2，4周，分别处死各组5只动物，获得脑组织标本，检测超氧化物歧化酶、丙二醛水平。 结果与结论：①在48 h内移植，移植后1，2周诱导转染骨髓基质干细胞组的NSS评分均显著低于诱导未转染骨髓基质干细胞移植组和颅脑损伤组(P<0.05)；各移植时间点，移植后3，4周，诱导转染骨髓基质干细胞移植组的NSS评分均显著低于诱导未转染骨髓基质干细胞移植组和颅脑损伤组(P<0.05)；②在大鼠损伤后24 h移植，移植第1周诱导转染骨髓基质干细胞组NSS评分显著低于颅脑损伤组(P<0.05)，移植第2，3，4周诱导转染骨髓基质干细胞移植组与诱导未转染骨髓基质干细胞移植组NSS评分均显著低于颅脑损伤组(P<0.05)；③移植后2周，诱导转染骨髓基质干细胞移植组的超氧化物歧化酶水平均显著高于诱导剂+培养基移植组和颅脑损伤组(P<0.05)，丙二醛水平显著低于上述两组(P<0.05)；④结果表明，β神经生长因子重组腺病毒转染骨髓基质干细胞在不同时间点移植治疗颅脑损伤大鼠，可以发挥出一定的神经保护作用。%BACKGROUND:Bone marrow stromal cel s can differentiate into nerve cel s to promote nerve tissue repair, but the exact mechanism has not been ful y elucidated. OBJECTIVE:To explore the influence of adenovirus-mediatedβnerve growth factor transfection on bone marrow stromal stem cel transplantation fighting against brain injury in rats. METHODS:(1) Rat bone marrow stromal stem cel s were cultured in vitro, transfected with the adenovirus-mediatedβnerve growth factor and directional y induced usingβ-mercaptoethanol. (2) A total of 210 Sprague-Dawley rats were randomized into induction+tranfection group, induction+non-transfection group, induction+medium group, model group, and sham group (n=42 per group). Rat skul injury models were made, and given corresponding treatments at different time points (12, 24, 36, 48, 72 hours). Neurological function of rats was evaluated based on neurological severity scores on the day that the rats were given transplantation, and 1, 2, 3, 4 weeks after transplantation. (3) Another 75 Sprague-Dawley rats were also divided into five groups (n=15 per group) as above, fol owed by model establishment and corresponding treatments at 24 hours after modeling. Neurological severity scores were recorded at the same day, 1, 2, 3, 4 weeks after transplantation. Five rats from each group were sacrificed to detect levels of malondialdehyde and superoxide dismutase in the rat brain at the same day, 2 and 4 weeks after transplantation, respectively. RESULTS AND CONCLUSION:If the cel s were transplanted within 48 hours after modeling, the neurological severity scores in the induction+transfection group decreased significantly compared with the induction+non-transfection group and model group at 1 and 2 weeks after transplantation (P<0.05). If the cel s were transplanted at different time, the neurological severity scores in the induction+transfection group were decreased significantly compared with the induction+non-transfection group and model group at 3 and 4 weeks after transplantation (P<0.05). If the cel s were transplanted within 24 hours after modeling, the neurological severity scores in the induction+transfection group decreased significantly compared with the model group at 1 week after transplantation (P<0.05), and the neurological severity scores in the induction+transfection group and induction+non-transfection group both were significantly lower than those in the model group (P<0.05). Two weeks after cel transplantation, the level of superoxide dismutase was significantly higher in the induction+transfection group than the induction+medium group and model group (P<0.05), but the level of malondialdehyde was significantly lower (P<0.05). Al these findings indicate that adenovirus-mediatedβnerve growth factor transfer plays a certain neuroprotective role in bone marrow stromal stem cel transplantation for brain injury in rats.
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