The Regulatory Role And Mechanism Of PRDX1 In Bleomycin Induced Pulmonary Fibrosis

Peroxiredoxin I(PRDX1)is one of the members of the peroxiredoxin family.PRDX1 can eliminate reactive oxygen species(ROS)within cells.PRDX1 plays an important role in cancer,and bleomycin(BLM)induces more severe lung inflammation and pulmonary fibrosis(PF)in PRDX1 gene knockout mice.At present,the drugs developed to treat PF have inevitable serious adverse reactions,and can only delay the failure of lung function,and cannot effectively reverse to achieve the purpose of curing the disease.Therefore,it is urgent to understand the pathogenesis of pulmonary fibrosis and find effective treatment methods.To explore the role of PRDX1 in BLM induced PF and the specific molecular mechanisms through which PRDX1 plays a role in BLM induced PF.This study further explored using methods such as Experimental methods such as MTT assay,Fibrosis morphological observation,Wound scratch assay,fluorescence microscopy,Flow Cytometric Detection,TGF-β1 ELISA kit,Western blot,Transcriptome sequencing analysis,and Histopathological observation.The loss of functional cells in lung tissue and the proliferation of lung fibroblasts are the two main reasons for the occurrence of pulmonary fibrosis.Therefore,this study is divided into three parts.The first part is the specific mechanism of PRDX1 in BLM induced lung epithelial cell injury.Lentivirus was used to transfect PRDX1 knockdown epithelial cells to construct Mock group and sh PRDX1 group cells.MTT assay showed that with the gradual increase of BLM drug concentration,the survival rate of PRDX1 knockdown cells was significantly increased,and the level of ROS in cells was also significantly increased,and the cell mitochondrial membrane potential was gradually decreased,which indicated that BLM treatment could induce mitochondrial damage through ROS,and knockdown PRDX1 could significantly promote mitochondrial damage.The sh PRDX1 group of cells underwent significant fibrotic morphological changes,and their migration ability was also significantly enhanced.The expression levels of epithelial mesenchymal transition(EMT)and fibrosis related marker proteins increased in sh PRDX1 group cells,indicating that knocking down PRDX1 can significantly promote the occurrence of EMT and further transition to interstitial cells.This process can activate the PI3K/AKT and JNK/Smad signaling pathways,with the JNK signaling pathway being more significantly activated.The treatment with PI3 K and JNK inhibitors further confirms the above results.The second part is about the regulatory role and mechanism of PRDX1 in the process of BLM-induced fibroblast proliferation and collagen secretion.PRDX1 gene knockout mouse were used.After PCR identification of mouse genotypes,two kinds of primary mouse lung fibroblasts were extracted.After BLM treatment,MTT assay results showed that PRDX1 knockout significantly promoted cell viability and proliferative ability,and promoted the secretion of TGF-β by fibroblasts,increasing intracellular ROS levels,and increasing cell migration ability compared to Mock.However,PRDX1 knockout had no significant impact on mitochondrial ROS and mitochondrial membrane potential.PRDX1 knockout can significantly affect the cyclin of cells,thereby promoting cell proliferation and the expression of fibrosis related proteins.These phenomena are mainly caused by the activation of PI3K/AKT and JNK/Smad signaling pathways.The third part conducts in vivo experiments using normal mouse and PRDX1 gene knockout mouse,use BLM to make models of fibrosis in mouse.The results showed that BLM induced more serious pulmonary fibrosis in PRDX1 knockout mouse,increased mortality,increased expression of cell proliferation-related protein and significantly changed fibrosis-related protein in lung tissue,and PI3K/AKT and JNK/Smad signal pathways were further activated.In summary,PRDX1 plays an important role in BLM-induced pulmonary fibrosis.On the one hand,BLM can cause the increase of ROS level in epithelial cells,which leads to the damage of cell mitochondria and the EMT or apoptosis of cells.Knocking down PRDX1 promotes epithelial cell damage by increasing cell ROS,thereby promoting the occurrence of pulmonary fibrosis.On the other hand,BLM can induce the proliferation of fibroblasts and the expression of collagen,and combined with in vitro and in vivo experiments,it is mainly through PI3K/AKT and JNK/Smad signal pathway.Knocking out PRDX1 can promote the development of pulmonary fibrosis by promoting fibroblast proliferation and collagen secretion.To further clarify the mechanism of PRDX1 in lung fibrosis induced by BLM,provide new inspiration and new theoretical basis for prevention or treatment of lung fibrosis,and provide more theoretical knowledge for PRDX1.These findings strongly suggest that PRDX1 is a key molecule in BLM-induced lung fibrosis progression through modulating the EMT and lung fibroblast proliferation;therefore,it may be a therapeutic target for the clinical treatment of BLM-induced lung fibrosis.