S-nitrosoglutationin as an inducer of nitrosative stress and apoptosis

Introduction. S-nitrosoglutathione is an S-nitrosylated derivative of glutathione and is considered an important mediator of the signaling effects of nitric oxide (II). In turn, nitric oxide can exhibit both regulatory and toxic effects due to the formation of active forms of nitrogen and nitrosylation of intracellular components, which can lead to the development of apoptosis. The role of nitric oxide in the regulation of apoptosis is dual, and therefore requires further study.

The aim of the work was to study the possibility of the development of nitrosative stress and apoptosis under the action of the NO donor – S-nitrosoglutathione.

Material and methods. The study was performed on a HepG2 cell culture. S-nitrosoglutathione was added to the cells at concentrations of 1, 10, 50, 100 μМ and incubated for 3 and 24 hours. Water (S-nitrosoglutathione solvent) was added to the control cells in an equivalent volume. Photometric methods were used to determine cell viability (MTT test), the concentration of nitric oxide and peroxynitrite metabolites. Expression of 3-nitrothyrosine, Bcl2 and Fas were detected by Western blot.

Results. S-nitrosoglutathione at a concentration of 100 μМ (24 h) decreased cell viability and increased concentration of peroxynitrite. The level of nitric oxide metabolites increased under the action of S-nitrosoglutathione at concentrations of 1–100 μМ and exposure periods of 3 and 24 hours, which led to an increase the expression of 3-nitrothyrosine. S-nitrosoglutathione with incubation for 3 hours and concentrations of 1–50 μM increased the level of Bcl2, at concentrations of 50–100 μM it decreased the content of Fas; when incubated for 24 hours and concentrations of 1-100 µM it decreased the level of Bcl2 and Fas.

Conclusion. Thus, in this study, it was found that S-nitrosoglutathione at concentrations of 1–50 μM and an exposure period of 3 hours has a signaling effect in HepG2 cells. S-nitrosoglutathione at a concentration of 100 μМ during incubation of 3 and 24 hours causes the development of nitrosative stress, which leads to the development of apoptosis and decreased cell viability.