TXNIP Promotes Silicosis Fibrosis By Regulating Prx-1 And Inflammatory Factors

Objective The study employed mice with silicosis and crystalline silica（Si O₂）-induced macrophage who bothly received treatment of TXNIP sh RNA lentivirus transfection,to detect the effect of thioredoxin-interacting protein（TXNIP）on pulmonary inflammation and fibrosis induced by Si O₂and explore the precious mechanism.The achievement could nourish the cognition of silicosis pathegenensis.Methods 12-week-old male mice were randomly divided into 4 groups:control group,silicosis group,silicosis+empty lentiviral vector group and silicosis+TXNIP lentiviral vector group;while RAW267.4 macrophages were separated with control group,Si O₂group,Si O₂+empty lentiviral vector group and Si O₂+TXNIP lentiviral vector group.All groups were received the stimulation of Si O₂instillation（2.5mg Si O2 for each mice and final Si O₂concentration of 50μg/ml for microphages）,except the control group which were given with normal saline;the dose of lentiviral transfection to each mouse was 10⁷TU and multiplicity of infection（MOI）of lentiviral transfection to macrophages regarded as20.The animals acquired Si O2 instillation and lentivirus via trachea and then were normally raised for 8 week.Macrophages endured the stilulation of Si O2 instillation for 24hours.The changes of pulmonary morphology and collagen deposition were checked by HE staining,VG and elastic staining respectively.Immunohistochemistry was used to measure the levels of TXNIP and 8-OHd G（a kind of DNA peroxide product）,while western blot was employed to assay the expressions of TXNIP,collagen type I（COL I）,α-smooth muscle actiin（α-SMA）,peroxiredoxin 1（Prx-1）,NOD-like receptor protein 3（NLRP3）,tumor necrosis factor-α（TNF-α）,interleukin-1（IL-1β）,interleukin-6（IL-6）,and transforming growth factor-β（TGF-β）.The ROS level in macrophages was measured by2,7dichlorodi-hydrofluorescein diacetate assay（DCFH-DA）.Results 1 Compared with the control,Si O₂could induce TXNIP expression,mainly located on silicotic nodules and alveolar septum,in a way of time dependence,which reaching at the peak when Si O₂continuted stimulating for eight weeks.2 TXNIP expressions in macrophages also could be quickly promoted with Si O₂stimulation,as the expression was most obvious with Si O₂stimulation of 6 hours and then gradually decreased.3 The transfection of TXNIP sh RNA lentivirus was able to decrease TXNIP level in normal mice and macrophages.4 Si O₂significantly induced the silicotic nodules formation and collagen deposition in lung,as well as improved the expressions of TXNIP,8-OHd G,Prx-1,NLRP3,TNF-α,IL-1β,IL-6 and TGF-βin mice,those changes being inhibited by TXNIP sh RNA treatment.5 The transfection of TXNIP sh RNA lentivirus also could significantly decrease the levels of TXNIP,8-OHd G,Prx-1,NLRP3,TNF-α,IL-1β,IL-6 and TGF-βin macrophages cocultured with crystalline silica instillation.Conclusions TXNIP plays an important role in promoting pulmonary fibrosis in silicosis,mediating by aggravation of oxidative stress which falicitates NLRP3 activation and synthesis of inflammatory factors in macrophages.At the same time,TXNIP can regulate Prx-1 expression of via the way of oxidative stress.Figure 16;Table 10;Reference 92...