| ObjectiveThe aim of this study was to investigate the mechanisms of Mycoplasmapneumonia-derived lipid-associated membrane proteins (LAMPs) inducing theexpression of heme oxygenase-1in human mononuclear cell line THP-1cells.MethodsTHP-1cells were cultured in vitro, and treated by different concentration of LAMPs,the mRNA and protein level of HO-1were detected by realtime-PCR and western blot,respectively. In the meanwhile, actinomycin D and cycloheximide were administeredto pretreat THP-1cell, subsequently challenged by5.0μg/mL LAMPs for16h, and theexpression of HO-1was detected by western blot. To determine the phosphorylationof Akt and the DNA-binding activity of Nrf2, western blot and electrophoreticmobility shift assay were used to detect the nucleoprotein and cytoplasm proteinextracted from the THP-1cell administered by LAMPs. The PI3K inhibitorLY294002was also administered to investigate the effects of LAMPs on the activityof Nrf2. At last, siRNA was used to confirm the involvement of Nrf2in regulation ofHO-1expression.Results（1）0~5μg/mL LAMPs induced the expression of HO-1mRNA and protein in adose-dependent manner in THP-1cells.（2）5μg/mL LAMPs could induce Akt phosphorylation in THP-1cells, and increasethe DNA-binding activity of Nrf2; PI3K inhibitor LY294002could significantlyinhibit its activity. （3）Silencing of Nrf2by siRNA could down-regulate the expressionHO-1inducedby LAMPs in THP-1cells.ConclusionsLAMPs induce the expression of HO-1in THP-1cell via PI3K/Nrf2pathways. |
PDF Full Text Request