Signaling by hydrogen sulfide (HS) and polysulfides (HS) in the central nervous system.

Hydrogen sulfide (HS) is a signaling molecule used to modify neuronal transmission, regulate vascular tone, protect tissues from oxidative stress, sense oxygen, and generate ATP. Hydrogen polysulfides (HS) have recently been identified as signaling molecules that mediate the activation of ion channels, regulation of tumor growth, and the transcriptional regulation of oxidative stress; some of which were previously ascribed to HS. Cystathionine β-synthetase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) are known as HS-producing enzymes. 3MST also produces HS and other persulfurated molecules such as cysteine persulfide, glutathione persulfide, and persulfurated proteins. The chemical interaction of HS and nitric oxide (NO) also produces HS, which may be the mechanism underlying the synergistic effect of HS and NO that was initially reported on vascular relaxation. HS and other persulfurated molecules elicit their effect via S-sulfuration (S-sulfhydration) of specific cysteine residues of the target proteins. This review article focuses on the production and roles of HS as well as HS in the central nervous system.