The role of hydrogen sulphide signalling in macrophage activation

Hydrogen sulphide (H(2)S) is the latest identified small gaseous mediator enabled by its lipophilic nature to freely permeate the biological membranes. Initially, H(2)S was recognized by its roles in neuronal activity and vascular relaxation, which makes it an important molecule involved in paracrine signalling pathways. Recently, the immune regulatory function of gasotransmitters, H(2)S in particular, is increasingly being appreciated. Endogenous H(2)S level has been linked to macrophage activation, polarization and inflammasome formation. Mechanistically, H(2)S‐induced protein S‐sulphydration suppresses several inflammatory pathways including NF‐κB and JNK signalling. Moreover, H(2)S serves as a potent cellular redox regulator to modulate epigenetic alterations and to promote mitochondrial biogenesis in macrophages. Here in this review, we intend to summarize the recent advancements of H(2)S studies in macrophages, and to discuss with focus on the therapeutic potential of H(2)S donors by targeting macrophages. The feasibility of H(2)S signalling component as a macrophage biomarker under disease conditions would be also discussed.