title: Inhibition of hydrogen sulfide production by gene silencing attenuates inflammatory activity by downregulation of NF-κB and MAP kinase activity in LPS-activated RAW 264.7 cells.
abstract: Hydrogen sulfide is an endogenous inflammatory mediator produced by the activity of cystathionine γ-lyase (CSE) in macrophages. The objective of this study was to explore the mechanism by which hydrogen sulfide acts as an inflammatory mediator in lipopolysaccharide- (LPS-) induced macrophages. In this study, we used small interfering RNA (siRNA) to inhibit CSE expression in macrophages. We found that CSE silencing siRNA could reduce the LPS-induced activation of transcription factor nuclear factor-κB (NF-κB) significantly. Phosphorylation and activation of extra cellular signal-regulated kinase 1/2 (ERK1/2) increased in LPS-induced macrophages. We showed that phosphorylation of ERK in LPS-induced RAW 264.7 cells reached a peak 30 min after activation. Our findings show that silencing CSE gene by siRNA reduces phosphorylation and activation of ERK1/2 in LPS-induced RAW 264.7 cells. These findings suggest that siRNA reduces the inflammatory effects of hydrogen sulfide through the ERK-NF-κB signalling pathway and hydrogen sulfide plays its inflammatory role through ERK-NF-κB pathway in these cells.
authors.affiliation: Department of Pathology, University of Otago-Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
authors.forename: Alireza
authors.initials: A
authors.lastname: Badiei
authors.affiliation: Department of Pathology, University of Otago-Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
authors.forename: Nethaji
authors.initials: N
authors.lastname: Muniraj
authors.affiliation: Department of Pathology, University of Otago-Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
authors.forename: Stephen
authors.initials: S
authors.lastname: Chambers
authors.affiliation: Department of Pathology, University of Otago-Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
authors.forename: Madhav
authors.initials: M
authors.lastname: Bhatia
mesh_terms: D000818:Animals; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D020868:Gene Silencing; D006862:Hydrogen Sulfide / Q000378:metabolism*; D007249:Inflammation / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D020935:MAP Kinase Signaling System / Q000235:genetics; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D010766:Phosphorylation; D034741:RNA, Small Interfering; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D008070:Lipopolysaccharides; D016328:NF-kappa B; D034741:RNA, Small Interfering; D009569:Nitric Oxide; D003542:Cystathionine gamma-Lyase; D006862:Hydrogen Sulfide