Silicosis is one of the most serious and prevalent occupational diseases globally,characterized by typical silicotic nodules and fibrosis.Recent studies suggest that the perinodular zone of the lung shares certain cha...Silicosis is one of the most serious and prevalent occupational diseases globally,characterized by typical silicotic nodules and fibrosis.Recent studies suggest that the perinodular zone of the lung shares certain characteristics with the nodules themselves.In this study,a silicotic rat model was established via a single intratracheal in-stillation of a 50 mg/mL silica suspension.Pulmonary anatomical and pathological examinations revealed that silica deposition induced severe alterations in both the nodular and perinodular tissues.Subsequently,pseudo-targeted metabolomics analysis revealed that abnormally elevated ornithine levels were closely associated with the progression of silicosis,from normal to perinodular and finally to nodular tissues.Immunofluorescent stain-ing demonstrated that,in addition to M2 macrophages,silica exposure increased the protein levels of ARG1 in epithelial cells,a finding further confirmed by in vitro experiments using A549 and BEAS-2B cells.Moreover,accumulated ornithine induced epithelial-mesenchymal transition in vitro,increased extracellular matrix expres-sion in NIH 3T3 fibroblasts,and enhanced TGF-β1 levels in RAW264.7 cells.Co-exposure to ornithine and silica significantly induced the aberrant expression of fibrosis-associated proteins compared to silica exposure alone,characterized by increased levels of FN and𝛼-SMA,as well as decreased E-cad expression.These findings sug-gest that silica exposure up-regulates ARG1 in various cells,leading to ornithine accumulation,which in turn accelerates the progression of fibrosis.展开更多
基金supported by the National Natural Science Foundation of China(No.81973466)the National Administration of Traditional Chinese Medicine Youth Qihuang Scholars Support Project,and the Program of Graduate Innovation Research in Shanxi Province(No.2023KY019).
文摘Silicosis is one of the most serious and prevalent occupational diseases globally,characterized by typical silicotic nodules and fibrosis.Recent studies suggest that the perinodular zone of the lung shares certain characteristics with the nodules themselves.In this study,a silicotic rat model was established via a single intratracheal in-stillation of a 50 mg/mL silica suspension.Pulmonary anatomical and pathological examinations revealed that silica deposition induced severe alterations in both the nodular and perinodular tissues.Subsequently,pseudo-targeted metabolomics analysis revealed that abnormally elevated ornithine levels were closely associated with the progression of silicosis,from normal to perinodular and finally to nodular tissues.Immunofluorescent stain-ing demonstrated that,in addition to M2 macrophages,silica exposure increased the protein levels of ARG1 in epithelial cells,a finding further confirmed by in vitro experiments using A549 and BEAS-2B cells.Moreover,accumulated ornithine induced epithelial-mesenchymal transition in vitro,increased extracellular matrix expres-sion in NIH 3T3 fibroblasts,and enhanced TGF-β1 levels in RAW264.7 cells.Co-exposure to ornithine and silica significantly induced the aberrant expression of fibrosis-associated proteins compared to silica exposure alone,characterized by increased levels of FN and𝛼-SMA,as well as decreased E-cad expression.These findings sug-gest that silica exposure up-regulates ARG1 in various cells,leading to ornithine accumulation,which in turn accelerates the progression of fibrosis.
