Hydrogen Sulfide and Polysulfide Signaling

Hydrogen sulfide (H₂S) has been demonstrated to have physiological roles such as neuromodulation, vascular tone regulation, cytoprotection, oxygen sensing, inflammatory regulation, and cell growth. Recently, hydrogen polysulfides (H₂Sn) have been found to be produced by 3-mercaptopyruvate sulfurtransferase and to regulate the activity of ion channels, tumor suppressers, and protein kinases. Furthermore, some of the effects previously reported to be mediated by H₂S are now ascribed to H₂Sn. Cysteine persulfide and cysteine polysulfide may also be involved in cellular redox regulation. The chemical interaction between H₂S and nitric oxide (NO) can also produce H₂Sn, nitroxyl, and nitrosopersulfide, suggesting their involvement in the reactions previously thought to be mediated by NO alone. This Forum focuses on and critically discusses the recent progress in the study of H₂Sn, H₂S, and NO as well as other per- or polysulfide species. Antioxid. Redox Signal. 00, 000-000.