P17 Hydrogen sulfide suppresses ox-LDL-stimulatedmonocyte chemoattractant protein-1 generation from macrophages via NF-κB pathway

Abstract

To examine the role of hydrogen sulfide (H 2 S) in oxidized low-density lipoprotein (ox-LDL)-stimulated monocyte chemoattractant protein-1 (MCP-1) generation from macrophages and possible mechanisms. THP-1 cells and RAW macrophages were pretreated with sodium hydrosulfide (NaHS), dl -propargylglycine (PPG) or hexyl acrylate (HA) and then treated with ox-LDL. Endogenous H 2 S pathway and MCP-1 generation were examined. The phosphorylation of NF- κ B p65 was detected by Western blotting. NF- κ B p65 nuclear translocation was detected using confocal images. NF- κ B p65 DNA binding activity was examined by electrophoretic mobility shift assay, ELISA and chromatin immunoprecipitation assay. The results showed that in THP-1 cells, ox-LDL treatment decreased H 2 S content, cystathionie-ß-sythase (CBS) protein and mRNA expression, but had no effect on cystathionine- γ -lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST) expression. Moreover, ox-LDL treatment significantly increased MCP-1 content and its protein and mRNA expression in both THP-1 cells and RAW macrophages, while PPG and HA promoted this increase further. However, NaHS markedly suppressed NF- κ B p65 phosphorylation, nuclear translocation and binding activity with MCP-1 promoter, resulting in a reduced generation of MCP-1 in ox-LDL treated THP-1 cells and RAW macrophages. Endogenous H 2 S/CBS pathway was down-regulated in ox-LDL-treated macrophages. H 2 S suppressed MCP-1 generation from ox-LDL-treated macrophages via suppressing NF- κ B p65 phosphorylation, nuclear translocation and the recruitment of NF- κ B p65 to the MCP-1 promoter region.