目的观察黄芪甲苷对短暂性前脑缺血大鼠海马神经干细胞增殖、分化的影响,探讨其促进神经发生和分化的作用.方法雄性SD大鼠随机分为假手术组,模型组,黄芪甲苷高、低剂量组(4、2 mg/kg),每组10只.短暂性前脑缺血后黄芪甲苷ip给药,模型组和假手术组ip给予生理盐水,1次/d,ip BrdU 10 mg/kg,2次/d,标记增殖细胞.各组分别于第7、14天后取脑组织,冰冻切片,行BrdU免疫荧光染色显示海马区域增殖的细胞,BrdU与MAP-2,GFAP等免疫荧光双标染色显示海马区域干细胞来源的成熟神经细胞和星形胶质细胞;取海马组织,RealTime RT-PCR法检测基本成纤维细胞生长因子(bFGF)、神经生长因子(NGF)、脑源神经营养因子(BDNF)、血管内皮生长因子(VEGF)mRNA的表达.结果黄芪甲苷高、低剂量,作用7 d后,可增加海马DG和CA1区BrdU阳性细胞数量和海马CA1区BrdU/GFAP阳性细胞数量;作用14 d后,可显著增加海马DG区BrdU/MAP-2双阳性细胞数量.其中,黄芪甲苷低剂量(2 mg/kg)作用7 d后可显著上调NGF mRNA表达.结论黄芪甲苷能够促进海马区神经干细胞增殖、分化,很可能与其上调NGF mRNA表达有关.

Objective To investigate the influence of astragaloside Ⅳ on proliferation and differentiation of neural stem cells in adult hippo-campus after transient forebrain ischemia.Methods The SD rats were randomly divided into Sham group,model group,astragaloside Ⅳ high dosage treatment group(4 mg/kg),and astragaloside Ⅳ low dosage treatment group(2 mg/kg).After transient forebrain ischemia,astragaloside Ⅳ was ip administration,Sham group and model group were ip administration of saline once per day.5-Bromodeoxyuridine(BrdU,10 mg/kg)was ip admi-nistration to label proliferating cells twice per day.The rats were sacrificed to be breaken out brain tissues as specimens after which they were treated by medicine for 7 and 14 d.By immunohistochemical immunofluorescence technique,the effect of every group on the immunoreactivity of BrdU,BrdU/microtubule-associated protein-2(MAP-2)and BrdU/glial fibrillary acidic protein(GFAP)after transient forebrain ischemia were observed for proliferation and differentiation of neural stem cells in the adult hippocampus.Simultaneity,Real Time polymerase chain react-ion(Real Time-PCR)was used to detect expression of bFGF,NGF,BDNF,and VEGF mRNA of adult hippocampus.Results Astragaloside Ⅳ,high and low dosage treatment groups,could increase the quantity of BrdU positive cells in DG and CA.and BrdU/GFAP both positive cells in CA.after administration 7 d,and could increase the quantity of BrdU/MAP-2 both positive cells in DG after administration 14 d.Among them,astragaloside Ⅳ,low dosage treatment group(2 mg/kg),could up-regulate the expression of NGF mRNA of adult hippocampus after administration 7d.Conclus-ion Astragaloside Ⅳ could promote proliferation and neuronal differentiation of the neural stem cells,it may relate to up-regulation of the expression of NGF mRNA of adult hippocampus.

国家自然科学基金资助项目(30472177)