Effects of transplanting BDNF overexpressed neural stem cells on neurotrophic factor induction hippocampus after radiation exposure / 中华放射医学与防护杂志

ABSTRACT

Objective To evaluate the effects of neural stem cells (NSCs) overexpressing brainderived neurotrophic factor (BDNF) on the levels of neurotrophic factors and microglia activation in hippocampus after brain irradiation.Methods Hippocampal NSCs were isolated from fetal rat brain and infected with GFP-lentivirus and GFP-BDNF-lentivirus.SD rats were randomized into four groupscontrol group,irradiated group (R group),GFP-modified NSCs transplantation group with irradiation (R+NSCs group),and GFP-BDNF modified NSCs transplantation group with irradiation (R+BDNF-NSCs group).NSCs were transplanted into the bilateral hippocampus of rats one month after whole brain irradiation at a single dose of 20 Gy.The expressions of BDNF,glial-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in hippocampus were detected at 2 and 8 weeks after transplantation.The activation of microglia was observed by immunofluorescence.Results At 2 and 8 weeks after transplantation,the expressions of BDNF and NGF proteins in hippocampus of R+BDNF-NSCs group were significantly higher than those of R group (P＜0.05).The activated microglia in the R+NSCs group and the R+BDNF-NSCs group had no decrease compared with R group (P＞ 0.05).Conclusions The transplantation of NSCs overexpressing BDNF promotes the production of BDNF and NGF,which improves the level of neurotrophic factors in hippocampus after radiation.