The Role Of Neutrophil Serine Protease In Systemic Lupus Erythematosus

Objective:Detected the plasma protein levels of neutrophil serine proteases(NSPs)—Neutrophil elastase(NE),Cathepsin G(CG),and Protease 3(PR3),the mRNA levels of NE,CG and PR3 in peripheral blood neutrophils(PMNs),the mRNA levels of Protease-activated receptor 2(PAR2),Interferon-γ(IFN-γ),Interleukin-10(IL-10)in peripheral blood mononuclear cells(PBMCs),and Nuclear factor-κB(NF-κB)protein levels in cell lysates in patients with systemic lupus erythematosus(SLE).After we treated human T lymphocyte leukemia(Jurkat)cells with NE,we detected the mRNA levels of PAR2,IFN-γ,IL-10 in cells and the protein level of NF-κB in cell lysates.To explore the level and clinical significance of NSPs in SLE,and the interaction between NE and PAR2,IFN-γ,IL-10,NF-κB in immune cells.Methods:A total of 114 SLE patients and 79 healthy controls were selected.The plasma protein levels of NE,CG and PR3 and the protein levels of NF-κB in cell lysates were detected by ELISA.The mRNA levels of NE,CG and PR3 in PMNs were detected by RT-qPCR.The mRNA levels of PAR2,IFN-γ and IL-10 in PBMCs were detected by RT-qPCR.Jurkat cells were cultured in vitro and treated with different concentrations of NE.After cultured for 6 h,12 h and 24 h,the mRNA levels of PAR2,IFN-γ and IL-10 and the protein level of NF-κB in cell lysate were measured.Results:The protein levels and and mRNA levels of NE,CG,PR3 in SLE group were higher than those in healthy control group(P<0.05).The analysis of clinical data showed that the protein and mRNA levels of NE,CG,PR3 in patients with SLE were positively correlated with SLE disease activity score(SLEDAI)(P<0.05).The incidence of clinical manifestations(mainly renal damage),the positive rate of self-antibody(mainly anti-dsDNA antibody)and the SLEDAI score in the elevated expression group of NE,CG and PR3 were higher than those in the normal expression group(P<0.05).The levels of PAR2,IFN-γ,IL-10 and NF-κB in the SLE group were higher than those in the healthy control group(P<0.05),and the level of PAR2 was positively correlated with the level of IFN-y(P<0.05).In the cell model,after Jurkat cells were treated with different concentrations of NE,the mRNA expression levels of PAR2,IFN-γ,IL-10 were increased in some concentrations and time periods(P<0.05),and showed a concentration-dependent change in some time periods.The higher the NE concentration,the higher the expression levels.The level of NF-κB increased when the NE concentration was 2IU/L12h(P<0.05).Conclusion:The level of NSPs in patients with SLE is significantly higher than that in healthy controls,and it is positively correlated with the disease activity of SLE.NSPs may be involved in the occurrence and development of SLE.The levels of PAR2,IFN-y,IL-10,and NF-κB were significantly increased in SLE patients,among which PAR2 was positively correlated with IFN-y,and they may play a role in the occurrence and development of SLE and have a certain relationship.NE can significantly stimulate the expression of PAR2,IFN-y,IL-10 and NF-κB in Jurkat cells.Whether NE plays a role in SLE by stimulating immune cells to increase the expression of PAR2,IFN-y,IL-10 and NF-κB signaling pathway,its specific mechanism deserves further study,which may provide a new idea for the treatment of the disease.