Hydrogen Sulfide: Biogenesis, Physiology, and Pathology

This is the authors' abstract. We don't add key points for this paper.

The seminal studies by Kimura's group in the late 1990s [1,2] ushered in a new era of biological signaling mediated by hydrogen sulfide (H 2 S).H 2 S has been described as the third "gasotransmitter" along with nitric oxide (NO) and carbon monoxide (CO; [3]).While none of these molecules actually signal as a gas, their hydrophilicity and lipophilicity enable them to readily traverse intracellular compartments where they serve in a variety of autocrine and paracrine signals capacities.Of the three, however, H 2 S is arguably the most chemically reactive and biologically diverse.As a weak acid, H 2 S exists as the dissolved gas and hydrosulfide anion (HS -) in nearly equal proportions in the circumneutral intracellular milieu.H 2 S is readily oxidized to per-and polysulfides (H 2 S ) forming a highly reactive group of molecules (reactive sulfide species, RSS) that readily form reversible covalent bonds, coordinate with metal ligands, and participate in a variety of redox reactions [4,5].H 2 S was key in the origin of life [6] and it remains as the only inorganic substrate used by eukaryotic cells to generate ATP [7].H 2 S mediates many physiological functions in various biological systems including cytoprotection, neuromodulation, ischemic responses, and oxygen sensing.Exogenous application of H 2 S may protect cell function against ischemic and oxidant injuries.Despite the fact that the multiple roles of H 2 S in biology have been intensely discussed over the last twenty years, many questions remain to be resolved.The eclectic nature of H 2 S is featured in this special issue as a collection of original articles and reviews that examine a variety of the physiological functions of H 2 S as well as its therapeutic attributes.