The Inhibition Effects of Sodium Nitroprusside on the Survival of Differentiated Neural Stem Cells through the p38 Pathway

Nitric oxide (NO) is a crucial factor in regulating neuronal development. However, certain effects of NO are complex under different physiological conditions. In this study, we used differentiated neural stem cells (NSCs), which contained neural progenitor cells, neurons, astrocytes, and oligodendrocytes, to observe the physiological effects of sodium nitroprusside (SNP) on the early developmental stage of the nervous system. After SNP treatment for 24 h, the results showed that SNP at 100 μM, 200 μM, 300 μM, and 400 μM concentrations resulted in reduced cell viability and increased cleaved caspase 3 levels, while no significant changes were found at 50 μM. There were no effects on neuronal differentiation in the SNP-treated groups. The phosphorylation of p38 was also significantly upregulated with SNP concentrations of 100 μM, 200 μM, 300 μM, and 400 μM, with no changes for 50 μM concentration in comparison with the control. We also observed that the levels of phosphorylation increased with the increasing concentration of SNP. To further explore the possible role of p38 in SNP-regulated survival of differentiated NSCs, SB202190, the antagonist of p38 mitogen-activated protein kinase, at a concentration of 10 mM, was pretreated for 30 min, and the ratio of phosphorylated p38 was found to be decreased after treatment with SNP. Survival and cell viability increased in the SB202190 and SNP co-treated group. Taken together, our results suggested that p38 is involved in the cell survival of NSCs, regulated by NO.