This study was designed to examine the role of
hydrogen sulfide (H2S) in the generation of
oxidized low-density lipoprotein (
ox-LDL)-stimulated
monocyte chemoattractant protein 1 (MCP-1) from macrophages and possible mechanisms. THP-1 cells and RAW macrophages were pretreated with
sodium hydrosulfide (
NaHS) and
hexyl acrylate and then treated with
ox-LDL. The results showed that
ox-LDL treatment down-regulated the H2S/
cystathionine-β-synthase pathway, with increased MCP-1
protein and
mRNA expression in both THP-1 cells and RAW macrophages.
Hexyl acrylate promoted
ox-LDL-induced
inflammation, whereas the H2S donor
NaHS inhibited it.
NaHS markedly suppressed NF-κB p65 phosphorylation, nuclear translocation,
DNA binding activity, and recruitment to the MCP-1 promoter in
ox-LDL-treated macrophages. Furthermore,
NaHS decreased the ratio of free
thiol groups in p65, whereas the
thiol reductant DTT reversed the inhibiting effect of H2S on the p65
DNA binding activity. Most importantly, site-specific mutation of
cysteine 38 to
serine in p65 abolished the effect of H2S on the sulfhydration of NF-κB and
ox-LDL-induced NF-κB activation. These results suggested that endogenous H2S inhibited
ox-LDL-induced macrophage
inflammation by suppressing NF-κB p65 phosphorylation, nuclear translocation,
DNA binding activity, and recruitment to the MCP-1 promoter. The sulfhydration of free
thiol group on
cysteine 38 in p65 served as a molecular mechanism by which H2S inhibited NF-κB pathway activation in
ox-LDL-induced macrophage
inflammation.