Effects of estradiol benzoate on proliferation and differentiation of in vitro cultured hippocampal neural stem cells

Objective To explore the potential mechanism of action of estradiol benzoate on proliferation and differentiation of rat hippocampal neural stem cells. Methods Hippocampus tissues from SD rats were dissociated and plated into culture flasks.Neural stem cells were identified by immunofluorescence against Nestin.After treatment with different concentration of estradiol benzoate(10-10, 10-9, 10-8, 10-7, 10-6 mol/L), the proliferation and differentiation of neural stem cells were assessed by MTT assay and the proportion of neurons and astrocytes in differentiated cells was assessed by flow cytometry.Western blot assay was performed to detect the expression levels of protein in neural stem cells. Results (1)The neural stem cells formed neurospheres and grew in floating, and were Nestin-positive.Estrogen receptors, including ERα and ERβ, were expressed in neural stem cells; (2)After treatment with 10-8 mol/L estradiol benzoate versus in the control group, the cell viability was significantly increased(t=5.36, P=0.003), and the ratio of neuron-specific nuclear protein(NeuN)-positive neuron cells in total cells was significantly increased(t=4.32, P=0.02), but the ratio of glial fibers acidic protein(GFAP)-positive cell in total cells was decreased(t=4.65, P=0.008). The expression levels of GDNF, GFRal and Ret proteins were enhanced in the estradiol benzoate group compared with the control group. Conclusions Appropriate concentration of estradiol benzoate promotes proliferation and differentiation ofin vitrocultured hippocampal neural stem cells and elevates the ratio between neurons and glial cells differentiated from neural stem cells. Key words: Estradiol; Stem cells; Hippocampus