RESUMO
Objective To explore the effect of folic acid on neural stem cells(NSCs) proliferation from fetal rats in vitro.Method NSCs were isolated and cultured by microdissection,mechanical blowing and serum-free suspension culture,and identified by immunofluorescent staining using antibody against nestin.BrdU(5’bromo-2’deoxyuridine) was used to mark dividing neural stem cells.Cultured NSCs were divided into four groups:control group,low,high dose group(liquid media with added 4,40 mg/L folic acid),and deficiency group(liquid media with added 0.4 mg/L methotrexate,MTX).Monotetrazolium(MTT) and double-label immunofluorescence technique detected NSCs proliferation under the condition of folic acid.Results In the serum-free suspension medium,neurospheres that consisted of a great number of nestin-positive cells could be obtained.The proliferative ability of NSCs were observed by BrdU labeling methods.MTT assay and double-label immunofluorescence for nestin+BrdU showed that the growth tendency was increased with folate concentration in the medium.Compared with control group,NSCs growth rate of folate group was significantly increased in vitro.Conclusion The culture of NSCs isolated from fetal rats possesses the abilities of proliferation and self-regeneration.Folic acid may stimulate proliferation of NSCs efficiently.