Exogenous Hydrogen Sulfide Regulates Mycoplasma Pneumoniae Lipid Associated Membrane Proteins To Inducethe Expression Of Heme Oxygenase-1 And Proinflammatory Cytokines

[Objective] Hydrogen sulfide?H₂S?, a colorless gas with strong odor of rotten eggs, is a ubiquitous gas produced endogenously in humanbodies. Lipid-associated membrane proteins?LAMPs? derived from Mycoplasma pneumonia?M.pneumoniae? plays a key role in the pathogenesis of severe inflammatory response induced by M.pneumoniae.Whereas it is still unclear how host cells regulate inflammatory responses and protect against dysfunctional inflammation during M.pneumoniae infection. The aim of this study is to explore the role of H₂S in M.pneumoniae LAMPs expressing of Interleukin6?IL-6?, Interleukin8?IL-8? and heme oxygenase-1?HO-1? in human monocyte cell line THP-1 cells, and to know the signal pathway of H₂S regulating LAMPs to express IL-6, IL-8 and HO-1. [Methods]The M.pneumoniae M129 strains were cultivated and the precipitate was collected by centrifugation to extracted LAMPs.BCA kit was performed for LAMPs concentration determination.THP-1 cells were pretreated with 400 ?M Na HS?a donor of H₂S? or other drugs?PDTC, PD98059, SB203580 or SP600125?before exposure to 5 ?g/m L LAMPs.Expression of IL-6 and IL-8 was detected by enzyme-linked immunosorbent assay?ELISA?. The phosphorylated protein and total protein of I?B-?, ERK, JNK and p38, the expression of HO-1, the cytoplasmic protein and nuclear protein of Nrf2 were detected by Western blot assay. [Results]?1? In the THP-1 cells which were pretreated with Na HS prior to exposure to LAMPs, the expression of HO-1 was increased 41.18% than no Na HS pretreated cells; The secretion of IL-6 and IL-8 in LAMPs stimulated THP-1 cells were suppressed by 19.02% and 11.56% respectively in Na HS pretreated cells when comparing with no Na HS handling cells.?2?When being pre-dealt with Na HS, the M.pneumoniae LAMPs stimulated THP-1 cells expressed Nrf2 protein in nuclei was 27% higher than no NaHS pretreated cells, and the Nrf2 protein in cytoplasm was 16.67% decreased than no Na HS group.?3? Pretreated with Na HS,the phosphorylated protein of ERK, JNK and p38 in THP-1 cells were all reduced by 27.14%, 16.67% and 31.00%respectively with the stimulation of M.pneumoniae LAMPs. When being pretreated with PD98059, SB203580, SP600125 before explore to M.pneumoniae LAMPs, the phosphorylated protein of ERK, JNK and p38 were all reduced by 28%?42.5%?40.2%.?4?The expression of p-I?B-? in THP-1 cells, induced by LAMPs, was inhibited by 17.65% when being pre-treated the cells with Na HS. Being pretreated with Na HS or PDTC, the secretion of IL-6 in M.pneumoniae LAMPs stimulating THP-1 cells were reduced by 24.69% and 30.43%,the level of IL-8 was decreased by 36.17% and 36.25%, respectively. [Conclusions]?1?IL-6 and IL-8 were attenuated by exogenous H₂S in M.pneumoniae LAMPs stimulated THP-1 cells via inhibiting MAPK/NF-?B pathway.?2? Exogenous H₂S promoted the nuclear translocation of Nrf2 and increased the expression of HO-1 in THP-1 cells.