Proteomics and Toxicity Analysis of Spinal-Cord Primary Cultures upon Hydrogen Sulfide Treatment

Hydrogen sulfide (H(2)S) is an endogenous gasotransmitter recognized as an essential body product with a dual, biphasic action. It can function as an antioxidant and a cytoprotective, but also as a poison with a high probability of causing brain damage when present at noxious levels. In a previous study, we measured toxic liquoral levels of H(2)S in sporadic amyotrophic lateral sclerosis (ALS) patients and in the familial ALS (fALS) mouse model, SOD1G93A. In addition, we experimentally demonstrated that H(2)S is extremely and selectively toxic to motor neurons, and that it is released by glial cells and increases Ca(2+) concentration in motor neurons due to a lack of ATP. The presented study further examines the effect of toxic concentrations of H(2)S on embryonic mouse spinal-cord cultures. We performed a proteomic analysis that revealed a significant H(2)S-mediated activation of pathways related to oxidative stress and cell death, particularly the Nrf-2-mediated oxidative stress response and peroxiredoxins. Furthermore, we report that Na(2)S (a stable precursor of H(2)S) toxicity is, at least in part, reverted by the Bax inhibitor V5 and by necrostatin, a potent necroptosis inhibitor.