Expression and activity of hydrogen sulfide generating enzymes in murine macrophages stimulated with lipopolysaccharide and interferon-γ.

Murine macrophages of the J774A.1 line are hydrogen sulphide-producing cells with the primary role of γ-cystathionase (CTH) and secondary role of 3-mercaptopyruvate sulfurtransferase (limited by cysteine availability) and with a negligible role of cystathionine ß-synthase (CBS) in H2S generation. J774A.1 cells stimulation with lipopolysaccharide (LPS) or interferon-gamma (IFNγ) resulted in decreased H2S levels after 24 h of incubation; however, they were restored to the control level after 48 h. Negligible CBS expression and activity in J774A.1 cells can result in homocysteine availability for CTH-catalyzed, H2S-generating reactions. This was supported by an increased CTH expression (IFNγ, 24 h and 48 h, and LPS, 48 h) and activity (24 h, LPS) in the stimulated cells. The results confirm the suggested feedback regulation between CBS and CTH.