BACKGROUND: Recombinant human erythropoietin (rhEPO) is a glycoprotein. Recent studies have demonstrated that rhEPO regulates many functional activities of neural cells. OBJECTIVE: To investigate the effects of different concentrations of rhEPO on proliferation of neural stem cells (NSCs) cultured in vitro. METHODS: Newborn Sprague-Dawley rat NSCs were harvested and cultured with serum-free culture medium containing different concentrations (5, 50, 500 U/mL) of rhEPO and 20 μg/L basic fibroblast growth factors (5, 50, and 500 U/mL rhEPO groups) and serum-free culture medium only containing 20 μg/L basic fibroblast growth factors (control group). After 7 days of culture, the cloning efficiency of NSCs was calculated. After 10 days of culture, neuron specific enolase (NSE)-and glial fibrillary acidic protein (GFAP)-immunoreactive cells were quantified. RESULTS AND CONCLUSION: In the rhEPO groups, cells proliferated rapidly, and the number of NSC microspheres was greater, in particular in the 50 U/mL rhEPO group, compared with the control group. NSCs grew faster in the 50 U/mL rhEPO group than in the control group. The number of NSE-and GFAP-immunoreactive cells was greater in the 50 U/mL rhEPO group than in the control group (P<0.01). These findings suggest that rhEPO promotes the in vitro culture and proliferation of NSCs, in particular 50 U/mL rhEPO.

BACKGROUND: There are fewer reports about estrogen effects on bone marrow stromal cells (BMSCs). OBJECTIVE: To study the effect of diethylstilbestrol on the osteogenic differentiation of rabbit BMSCs. METHODS: Rabbit BMSCs cultured in vitro were intervened with 0, 10-7, 10-6, 10-5 mol/L diethylstilbestrol, and BMSCs cultured with dexamethasone 10-8 mol/L, β-sodium glycerophosphate 10 mmol/L, and vitamin C 50 mg/L were used as positive controls. RESULTS AND CONCLUSION: 10-6 mol/L diethylstilbestrol significantly improved the proliferative ability of BMSCs at 24, 48, and 72 hours after intervention (P < 0.01). 10-5 mol/L diethylstilbestrol significantly inhibited the proliferation of BMSCs at 48 hours after intervention as well as 10-7 mol/L diethylstilbestrol at 72 hours (P < 0.01). Mineralized nodular structures formed at 25 days after intervention with 10-7 mol/L diethylstilbestrol. Alkaline phosphatase activities were remarkably increased at 14 and 21 days after intervention with 10-7, 10-6 mol/L diethylstilbestrol. It has been proved that diethylstilbestrol has an enhancing effect on the osteogenic differentiation of rabbit BMSCs.