POM121 Inhibits Macrophage Inflammatory Response Through Decreasing NF-?B P65 Nuclear Import

Inflammatory response is a common phenomenon in many clinical diseases induced by viruses,bacteria,fungi and trauma.In the early stage of infectious diseases,macrophages play a crucial role in resistance and clearance of antigen.Macrophages are activated by pathogen stimulation and secret inflammatory cytokines.Antigen recognitions and intracellular immune signal pathway have been most researched in infectious diseases.It was previously reported that POM121 is significantly down-regulated in macrophages after LPS stimulation,suggesting the involvment of POM121 in LPS-induced macrophage inflammatory response.POM121 is a 145 k Da transmembrane protein and locate in the nuclear membrane.The N terminal is transmembrane structural and nuclear membrane domain and the C terminal is FG repeat,which plays an important role in biological macromolecular nuclear transportation.However,POM121 function in macrophages is yet unknown.In this study,eukaryotic expression plasmid pMSCV-eGFP-POM121 was constructed and packaged into a retrovirus for the infection of RAW264.7.POM121 over-expression macrophage stable cell line was then generated.We stimulated the stable cell line with POM121 over-expression and found that POM121 inhibited the expression and secretion of inflammatory cytokines.Furthermore,we conditionally knocked out POM121 in mice by cas9 technology.Mice with POM121 deficeinet in myeloid cells were obtained by hybridizating with Lyzm-Cre mice.Bone marrow derived macrophages were stimulated in vitro and results showed that inflammatory response aggravated with POM121 deficeint in macrophages.Mice sepsis model was established by intraperitoneal injection of LPS.We found inflammatory response was enhanced in POM121 knock-out mice evidenced by increased inflammatory cytokines expression,aggravated lung pathological progress and reduced survial.To further identify POM121 function on macrophages,p65 in NF-?B signaling pathways and phosphorylated p38,JNK and Erk in MAPK signal pathway were detected.Our data indicated that POM121 does not effect phosphorylation of p65 in cytoplasm.However,POM121 over-expression in RAW264.7 cells decreased the p-p65 nuclear while POM121 knockout BMDMs showed more p-p65 in nucleus.Above all,we conclude that POM121 may suppress macrophage inflammatory response through inhibition of p-p65 nuclear import.