Potassium aspartate inhibits SH-SY5Y cell damage and apoptosis induced by ouabain and H2O2

Abstract

The present study aimed to investigate the effects of L-aspartic acid potassium salt (potassium aspartate, K-asp) on SH-SY5Y cells treated with ouabain and H2O2. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to investigate the effects of K-asp on SH-SY5Y cell death induced by ouabain. Nissl staining was used to demonstrate the morphological changes of the SH-SY5Y cells. Light microscopy and 4',6-diamidino-2-phenylindole (DAPI) staining were performed to visualize apoptosis in SH-SY5Y cells incubated with ouabain for 6, 24 and 48 h. Transmission electron microscopy was used to observe the effect of K-asp on ultrastructural changes of the SH-SY5Y cells following incubation with ouabain for 24 and 48 h. An annexin V-fluorescein isothiocyanate/propidium binding assay and flow cytometry were performed successively to investigate how K-asp affected the H2O2-induced cell apoptosis. The MTT assay demonstrated that K-asp attenuated the cytotoxicity of the SH-SY5Y cells following treatment with ouabain, in a dose-dependent manner. The cell survival rates following 48 h incubation in the K-asp (15 mM) and K-asp (25 mM) groups were higher compared with the KCl and MK801 groups. Nissl staining demonstrated that the severity of cell injury in the KCl and K-asp (25 mM) groups were alleviated. In the DAPI staining and transmission electron microscopy analyses, KCl and K-asp (25 mM) reduced the rate of ouabain-induced apoptosis. Flow cytometry revealed that K-asp (25 mM) reduced H2O2 -induced apoptosis. These results demonstrated that K-asp (25 mM) inhibited the ouabain and H2O2-induced SH-SY5Y cell damage and apoptosis, possibly by supplementing levels of intracellular K(+).