The effect of Mash-1 gene overexpression on neural cell proliferation, differentiation and learning and memory ability in C57BL/6 adult male mice after brain trauma / 临床神经病学杂志

ABSTRACT

Objective To investigate the effects of Mash-1 gene overexpression on neural cell proliferation, differentiation and learning and memory ability in C57BL/6 adult male mice after brain trauma. Methods One hundred and sixty healthy adult male C57BL/6 mice were randomly divided into sham operation group, simple trauma group, negative control group and overexpression group. Gene transfection using recombinant adenovirus Ad5-mMash-1. Detection of Mash-1 mRNA level by RT-PCR at 1 d before TBI and 1 d, 3 d, 7 d, 14 d after traumatic brain injury (TBI). Western blotting was used to detect the expression of Mash-1 protein. The learning and memory ability was evaluated by means of water maze. The proliferation of nerve cells in dentate gyrus and cerebral cortex of hippocampus at 3 d and 7 d after TBI were detected by immunofluorescence. Results Compared with those in sham operation group, the relative expression of Mash-1 mRNA in simple trauma group and negative control group at 1 d, 3 d, 7 d, 14 d after TBI were significantly lower (P<0. 05-0. 01), and the relative expression of Mash-1 mRNA in overexpression group at 1 d, 3 d, 7 d, 14 d after TBI were significantly higher ( all P<0. 01 ). The relative expression of Mash-1 mRNA in overexpression group at 1 d , 3 d , 7 d , 1 4 d after TBI were significantly higher than those in simple trauma group and negative control group (all P<0. 05). Compared with those in sham operation group, expression of Mash-1 protein in simple trauma group at 1 d, 7 d, 14 d after TBI and negative control group and overexpression group at 1 d, 3 d, 7 d, 14 d after TBI (P<0. 05 -0. 01), expression of Mash-1 protein in simple trauma group at 3 d after TBI (P<0. 05). The expression of Mash-1 protein in overexpression group at 1 d, 3 d, 7 d, 14 d after TBI were significantly higher than those in simple trauma group and negative control group (all P<0. 05). Compared with those in sham operation group, the number of BrdU positive cells in simple trauma group at 3 d, 7 d after TBI and the number of DCX positive cells at 3 d after TBI were significantly decreased (P<0. 05-0. 01), and they were significantly increased in overexpression group (all P<0. 05). The number of BrdU positive cells at 3 d, 7 d after TBI and the number of DCX positive cells at 3 d after TBI in overexpression group were significantly increased than those in simple trauma group (all P<0. 05). There was no statistical difference of escape latency between simple trauma group, negative control group and overexpression group at 1 d, 3 d, 7 d, 14 d after TBI (all P>0. 05). Compared with those in sham operation group, escape latency in simple trauma group, negative control group and overexpression group at 1 d, 3 d, 7 d, 14 d after TBI were significantly increased (all P<0. 05). Conclusion Overexpression of Mash-1 gene increases neuronal proliferation and differentiation in dentate gyrus and cortex of adult C57BL/6 mice after traumatic brain injury, but it has no effect on learning and memory ability.