Abstract
Hydrogen sulfide (H(2)S), previously only considered a toxic environmental air pollutant, is now increasingly recognized as an important signaling molecule able to modulate several cellular pathways in many human tissues. As demonstrated in recent studies, H(2)S is produced endogenously in response to different cellular stimuli and plays different roles in controlling a number of physiological responses. The precise role of H(2)S in inflammation is still largely unknown. In particular, the role of H(2)S in the regulation of the inflammatory response in acute and chronic infections is being actively investigated because of its potential therapeutic use. To study the effect of H(2)S as an anti-inflammatory mediator during bacterial infections, we developed an ex vivo model of primary cells and cell lines infected with Mycoplasma. Our data demonstrate a dichotomic effect of H(2)S on the NF-kB and Nrf-2 molecular pathways, which were inhibited and stimulated, respectively.