Study on apoptosis by amyloid-β protein in embryo-rat cerebral neural stem cells

Objective To study the apoptotic effect of amyloid-β protein (Aβ) on neural stem cells (NSCs) in rat fetal cerebrum in vitro. Methods The NSCs of rat fetal cerebrum cultured up to 7 d were divided into control and experimental groups. In experimental group 5 subgroups were divided according to the end concentration of Aβ1-40 as 0.1, 1.0, 5.0, 10.0 and 20.0 μmol/L and cultured 12 h, 24 h, 48 h and 72 h respectively. The optimal concentration of Aβ1-40 for inducing appotosis of NSCs was screened by MTT test, then NSCs were co-cultivated with Aβ1-40 at the optimal concentration. The early apoptosis of NSCs was observed by Annexin-V-Fluorescence while the late apoptosis of NSCs was observed by TUNEL fluorescence staining method. Results 1) It was demonstrated by MTT screening experiment, the optimal end concentration of Aβ1-40for inducing NSCs apoptosis was 5 μmol/L of Aβ1-40. 2) The early apoptosis of NSCs appeared when NSCs co-cultivated with 5 μmol/L Aβ1-40 up to 6 h. A lot of green fluorescence markers were found in apoptotic cells by Annexin-V-fluorescence staining and it was not found in the control. 3) The advanced apoptosis of NSCs appeared when NSCs co-cultivated with Aβ1-40 (5 μmol/L) up to 24 h and the green markers were found in cells by TUNEL fluorescence staining. Conclusion It is demonstrated that Amyloid-β protein can induce apoptosis of NSCs in rat fetal cerebrum.