Regulatory Effect Of Prx-2 On SiO₂-induced Oxidative Stress And Macrophage Polarization

Objectives Prx-2 protein was overexpressed by lentiviral transfection technology to investigate the relationship between Prx-2 and reactive oxygen species ROS and macrophage polarization,as well as its potential possible mechanism of action.Methods 1 In vivo experiment:8-week-old C57/BL male mice were randomly divided into control group,silicosis group,transfection control group and Prx-2 transfection group according to whether bronchial perfusion of Si O₂,NC+Si O₂ and Prx-2+Si O₂ was mixed or not,with 10 mice in each group;they were routinely fed for 2 weeks after modeling;2 weeks later,the bronchoalveolar lavage fluid of mice in each group was extracted to make smears for subsequent experimental studies.2 In vitro experiments:RAW267.4 macrophage cell line was selected NC stable transplants and Prx-2 stable transplants using lentiviral transfection technique,and divided into control group,Si O₂ group,NC+Si O₂ group and Prx-2+Si O₂ group according to whether 50ug/ml Si O₂ stimulation was given or not;reactive oxygen species（ROS）levels were measured by immunohistochemistry and DCFH-DA fluorescence probe method;Co-expression of macrophages and M1/M2 macrophages was detected by immunofluorescence double labeling method;and the expression levels of Prx-2,NF-κB,TNF-αand P-SRC were detected by Western blot.Results 1 As has been shown in Immunohistochemistry,silicosis group and transfection control group had obviously higher positive expression of 8-OHd G than control group（P<0.05）.Instead,the positive expression of 8-OHd G lower apparently in Prx-2 transfected group compared to that in silicosis group and transfection control group（P<0.05）.2Immunofluorescence showed that the proportion of M1 macrophages in total macrophages was significantly increased in the silicosis group and the transfected control group compared with the control group（P<0.05）;conversely,the proportion of M1 macrophages in Prx-2transfected group was significantly decreased compared with the above two groups（P<0.05）;On the contrary,There was no significant change in the proportion of M2 macrophages in silicosis group,transfected control group and Prx-2 transfected group.3 the DCFH-DA test result prompted,compared with the control group,the fluorescence OD value in Si O₂ group and NC+Si O₂ group increased significantly（P<0.05）.Compared with the two groups,the fluorescence OD value of Prx-2+Si O₂ group decreased significantly（P<0.05）.4 Compared with the control group,the expression of Prx-2,NF-κB,P-SRC and TNF-αin Si O₂ group and NC+Si O2 group were all up-regulated（p<0.05）.Compared with the two groups,the expressions of NF-κB,P-SRC and TNF-αwere all down-regulated,while the expression of Prx-2 was further up-regulated.Conclusions Overexpression of Prx-2 protein can inhibit ROS production,affect macrophage enrichment and polarization of M1 type macrophages,inhibit activation of NF-κB/SRC pathway,thereby reducing secretion of inflammatory factors such as TNF-α,inhibiting inflammation and slowing down the occurrence and development of silicosis.Figure9;Table5;Reference 164...