动物造模,神经干细胞移植 z-bio 2023-03-09 695

　　Objective: To investigate the effect of bcl-2 gene-modified neural stem cell transplantation on the recovery of injured nerve function in rats with spinal cord injury.

　　Methods: Rat neural stem cells were cultured in vitro, and the neural stem cells were transfected with Ad-EGFP mediated terminal B-lymphoma-2 gene (bcl-2) gene, and divided into 3 groups: control group, negative transfection group, bcl-2 -2 transfection group. Western-blot detection of bcl-2 protein expression in neural stem cells before and after transfection. 85 adult female SD rats, 72 of which were successfully modeled, were randomly divided into control group, NSCs group, bcl-2-NSCs group, 24 rats/group, and the rat model of acute spinal cord injury was established according to the modified Allen strike method. Motor function was assessed by BBB score and inclined plate test. Seven days after modeling, the expression of HSP27 and c-fos genes around the spinal cord injury area were detected by RT-PCR and Western-blot, and cell apoptosis was detected by TUNEL method. 4 weeks after modeling, pathological section HE staining and fluorescence microscope were used to observe the survival and distribution of EGFP-labeled NSC, and SEP and MEP were used to observe the neurophysiological recovery of rats.

　　Results: After the bcl-2 gene was transfected into rat neural stem cells, the bcl-2 gene and protein levels were expressed in the bcl-2 transfection group compared with the control group and the negative transfection group (P<0.05). Functional evaluation bcl-2-NSCs group was better than NSCs group, NSCs group was better than control group. At 72 h after modeling, the number of apoptotic cells in bcl-2-NSCs group was significantly lower than that in control group and NSCs group (P<0.05). 7 days after modeling, compared with the control group and NSCs group, the expression of HSP27 gene and protein in bcl-2-NSCs group were significantly increased (P<0.05), and the expression of c-fos gene and protein in bcl-2-NSCs group was significantly increased (P<0.05). The expression was significantly decreased (P<0.05). Four weeks after modeling, the loss of spinal cord tissue and the formation of syringomyelia were seen in the HE staining control group, and no nerve axons passed through. In the NSCs group, a few axon-like structures were found in the injured area, and the syringomyelia was smaller. In the bcl-2-NSCs group, there were more axon-like structures and no syringomyelia. The number of EGFP-labeled positive cells: the bcl-2-NSCs group was the most, followed by the NSCs group, but not in the control group, and there was a significant difference between the groups (P<0.05). Four weeks after modeling, the latency of SEP and MEP: bcl-2-NSCs group < NSCS group < control group, and there was significant difference between the groups (P < 0.05); amplitude: bcl-2-nscs group >NSCs group> control group, and there was significant difference between the groups (P<0.05).