Hydrogen sulfide attenuates TMAO-induced macrophage inflammation through increased SIRT1 sulfhydration

Chronic inflammation is a key factor that accelerates the progression of inflammatory vascular disease. Hydrogen sulfide (H2S) has potent anti-inflammatory effects; however, its underlying mechanism of action has not been fully elucidated. The present study aimed to investigate the potential effect of H2S on sirtuin 1 (SIRT1) sulfhydration in trimethylamine N-oxide (TMAO) -induced macrophage in.ammation, and its underlying mechanism. Pro-inflammatory M1 cytokines (MCP-1, IL-1 beta, and IL-6) and anti-inflammatory M2 cytokines (IL-4 and IL-10) were detected by RT-qPCR. CSE, p65 NF-kappa B, p-p65 NF-kappa B, IL-1 beta, IL-6 and TNF-alpha levels were measured by Western blot. The results revealed that cystathionine gamma-lyase protein expression was negatively associated with TMAO-induced inflammation. Sodium hydrosulfide (a donor of H2S) increased SIRT1 expression and inhibited the expression of inflammatory cytokines in TMAO-stimulated macrophages. Furthermore, nicotinamide, a SIRT1 inhibitor, antagonized the protective effect of H2S, which contributed to P65 NF-kappa B phosphorylation and upregulated the expression of inflammatory factors in macrophages. H2S ameliorated TMAO-induced activation of the NF-kappa B signaling pathway via SIRT1 sulfhydration. Moreover, the antagonistic effect of H2S on inflammatory activation was largely eliminated by the desulfhydration reagent dithiothreitol. These results indicated that H2S may prevent TMAO-induced macrophage in.ammation by reducing P65 NF-kappa B phosphorylation via the upregulation and sulfhydration of SIRT1, suggesting that H2S may be used to treat in.ammatory vascular diseases.

Automated summary

This study found that hydrogen sulfide (H2S) can alleviate macrophage inflammation by regulating the sulfhydration of SIRT1. In addition, H2S also reduces inflammation by inhibiting the expression of inflammatory cytokines and decreasing the phosphorylation of P65 NF-kappa B in TMAO-induced inflammation. Therefore, H2S may be used for the treatment of inflammatory vascular diseases.