Role Of Pyroptosis Mediadted By MARCO In The Pathogeny Of Silicosis

Objective To explore the regulatory effect of pyroptosis mediated by MARCO on silicosis fibrosis,and clarify the effect and mechanism of targeted blockade the gene of MARCO on the MARCO-pyroptosis-silicosis fibrosis disease axis.Methods 1 MARCO gene deficient(MARCO^-/-)C57BL/6 mice were constructed using CRISPR/Cas9 technology,as well as silicosis models of WT mice and MARCO^-/-mice were established,and the lung fibrosis changes were observed at days 0,7,14,28,56 and84.2 Analyzed the GSE44294 microarray dataset in the GEO database and screened for differentially expressed genes.3 MARCO knockdown Thp-1 cells were established models of SiO₂induced macrophage injury and then observed the pyroptosis pathway and macrophage injury.4 WT and MARCO^-/-mice were used to construct silicosis fibrosis models and control models,and the pyroptosis pathway and fibrotic changes of silicosis in lung tissues of mice at 28 d and 56 d were observed.5 Application of Poly G intervention to SiO₂induced J774A.1 murine macrophage injury models to observe pyroptosis pathway changes and cell injuries.6 Used Poly G prophylactic intervention in mice models of silicosis fibrosis to study MARCO and pyroptosis pathways as well as fibrotic changes in the lungs of mice at 28 and 56 d.7 Therapeutic intervention with Poly G for 28 d in silicosis fibrosis models of mice was used to evaluate the changes of MARCO and pyroptosis pathways as well as fibrotic changes in lungs of 56 d mice.Results 1 After SiO₂intervention,the degree of fibrosis in the silicosis fibrosis model of WT mice was aggravated with the extension of observation time;The lung tissue of MARCO^-/-mice at each observation time was mainly characterized by inflammatory responses of varying degrees,and a few cellular nodules were observed in the lung tissue of some mice at 56 d and 84 d;MARCO^-/-mice have less fibrosis than WT mice,and there is an interactive effect between the time of establishment of the silicosis fibrosis model and the genotype of the mouse on exacerbation of silicosis fibrosis（F=8.82,P<0.001）.2 The collagen deposition in lung tissue of WT mice increased with the extension of observation time;Few abnormal collagen deposits were observed in the interstitial lung tissue of MARCO^-/-mice at 56 and 84 d of observation;The collagen content of lung tissue from WT mice was higher than that of MARCO^-/-mice at the same time points since the 28 d observation point,all P<0.001;There was an interactive effect between the time of establishment of the in silico fibrosis model and mouse genotype on the relative collagen content of mouse lung tissue（F=80.21,P<0.001）.3 The expresson of lung tissues in WT mice VIM,α-SMA,Col I and col III were more highly expressed than in MARCO^-/-mice.The expression of VIM,α-SMA colⅠand colⅢincreased with the time of model（F=6.84,4.90,4.62,10.10;all P<0.05）.4 Bioinformatic analysis of the GSE44294 dataset revealed that there were 52 differential genes associated with NOD like signaling pathway after macrophage induction by SiO₂,and several genes including Nlrp3,Casp1,IL1b,and IL18were up-regulated and strongly correlated with MARCO.5 In the SiO₂-induced Thp-1（M?）cell injury models,the expression of NLRP3,Caspase-1-p20,GSDMD-N,IL-1βin wild Thp-1（M?）cells was higher than that in KDMARCO Thp-1（M?）cells（all P<0.05）.6MARCO deficiency could not only reduce the protein expression of NLRP3,Caspase-1-p20,GSDMD-N,and IL-1βin the lung tissues of mice with silicotic fibrosis,but also reduce the expression of VIM,α-SMA,ColⅠand ColⅢ,thereby alleviating silicotic fibrosis in mice（all P<0.05）.7 Poly G suppressed SiO₂-induced pyroptosis in J774A.1murine macrophages,and had a certain protective effect on macrophages at a reasonable dose.Poly G intervention downregulated the protein expression levels of MARCO,NLRP3,Caspase-1-p20,GSDMD-N,IL-1βand IL-18 during the induction（all P<0.05）.8 Poly G prophylactic intervention and therapeutic intervention in mice models of silicosis fibrosis down regulated the expression levels of MARCO,NLRP3,caspase-1-p20,GSDMD-N,IL-1β,IL-18,α-SMA,VIM,ColⅠ,and ColⅢin the lung tissues of of mice（all P<0.05）,and could alleviate the progression of silicosis fibrosis to some extent.Conclusions 1 MARCO is involved in the regulation of pyroptosis,MFS differentiation and ECM deposition during silicosis.2 Poly G targeted intervention with MARCO effectively inhibited the level of pyroptosis by SiO₂mediated and slowed down the fibrotic process in silica.3 The MARCO-pyroptosis-silicosis fibrosis disease axis played an essential role in the development and progression of silicosis fibrosis,and inhibition of MARCO by endogenous and exogenous could inhibit the activation of pyroptosis pathways and reduce the differentiation of MFs and abnormal ECM deposition in lung tissues,delayed the occurrence and development of silicotic fibrosis.Figure 73;Table 14;Reference 226...