| OBJECTIVE Exploring the Potential Correlation of Serum Uric Acid with Inhibition of Monocyte-Macrophage-Induced Fibrosis in Patients with Silicosis.METHOD(1)A retrospective analysis was conducted on medical records of 60 patients with silicosis who were treated at the Respiratory Department of the The Second Hospital of Heilongjiang Province from January 2022 to December 2022.Bronchoalveolar lavage fluid samples were also collected and preserved.The analyzed materials included biochemical indicators,blood routine examination,basic information,blood gas analysis,and other contents.After using independent sample t-test and chi-square test to analyze the medical records,the main protective and risk factors were identified.Logistic regression analysis was then used to further analyze the relevant factors and identify the main contributing factors.(2)Transcriptional profiling analysis was conducted on monocytes cultured in RPMI1640 medium supplemented with uric acid(UA)and stimulated with LPS,as well as on macrophages cultured in RPMI1640 medium and stimulated with LPS,using the GSE107821 m RNA public gene chip dataset from the National Center for Biotechnology Information(NCBI)website in the United States.The samples included four human monocytes stimulated with LPS for 24 hours and cultured in RPMI1640 medium with added uric acid,as well as four macrophages stimulated with LPS for 24 hours and cultured in RPMI1640 medium.The limma package in R was used to identify differentially expressed genes,and genes meeting the criteria of a small probability event and with a filtering threshold of log2 FC ≥ 1 or log2FC≤-1 were selected using Microsoft Excel 2007 software.(3)A rat model of silicosis pulmonary fibrosis was established using the non-exposed intratracheal instillation method with silica dioxide.Thirty 140±10g SPF-grade Wistar rats were randomly divided into a control group of 10 and a modeling group of 20.The control group was intratracheally instilled with 1.00 m L of physiological saline,while the modeling group was instilled with 1.00 m L of 50.0 mg.m L-1 Si O2 water suspension to prepare the silicosis pulmonary fibrosis model.On the 28 th day,blood was collected from the tail vein to measure blood uric acid levels.Then,the rats were euthanized,and lung tissue was collected and preserved at ultra-low temperatures.Proteomic analysis was performed using mass spectrometry,and the upregulated protein names in the results were compared with the downregulated gene names in the analysis results of silicosis patients through homologous conversion.The main genes related to the inhibition of lung fibrosis associated with blood uric acid were identified using DAVID online analysis.(4)Masson staining and transmission electron microscopy were used to observe and analyze the lung tissue of rats in the silicosis pulmonary fibrosis model.RT-q PCR was used to detect the main functional site genes in the bronchoalveolar lavage fluid of silicosis patients that overlapped with the proteomic analysis.All data were analyzed using SPSS 26.0 software and expressed as mean ± standard deviation.After verifying homogeneity of variance for all samples,the ROC diagnostic results for uric acid levels and silicosis staging in patients were analyzed to identify changes in the expression levels of relevant genes during monocyte-macrophage-induced fibrosis after being influenced by blood uric acid.RESULT(1)Among 60 patients with silicosis,according to clinical staging,43 patients were in stage I,including 40 males and 3 females,with a mean age of 67.97 ± 10.55 years;17 patients were in stage II or above,all of whom were males,with a mean age of 68.47 ± 14.15 years.In the chi-square test or t-test,there were statistically significant differences in Apo B,BASO,CHOL,LDL,LYMPH#,NEUT#,PA,TBA,TG,UA,and WBC.The logistic binary regression analysis showed that UA had the most significant effect.The patients’ serum uric acid levels were grouped into a high uric acid group(> 336 μmol·L-1)and a low uric acid group.The χ~2 test showed that there was a statistically significant difference between the two groups in terms of silicosis staging and serum uric acid level grouping(χ~2 = 9.506,P =0.00205).(2)In the gene dataset GSE107821,a total of 5,784 serum uric acid-activated human mononuclear cells were found to be expressed,with 3,181 upregulated and 2,603 downregulated.GO analysis revealed that the biological processes included neutrophil activation involved in immune response,neutrophil degranulation,T-cell activation,regulation of myeloid cell differentiation,regulation of leukocyte differentiation,regulation of hematopoietic cell adhesion,negative regulation of phospholipid metabolic process,negative regulation of hemostasis and immune system process.The cellular components included secretory granule membrane-specific granule,MHC class Il protein complex,tertiary granule secretion within cytoplasmic vesicles,specific granules within granule lumen,primary lysosome membrane azurophilic granule,while molecular functions included phosphoric ester hydrolase activity,serine/threonine kinase activity,MHC class Il receptor activity,GTPase activator activity,RAGE receptor binding,GTPase regulator activity,guanyl-nucleotide exchange factor activity,phosphatase activity,and actin binding.Enrichment analysis of downregulated genes revealed that biological processes included defense response to virus,response to virus,inflammatory response,cell response to lipopolysaccharide,cell response to interferon-gamma,cell response to IL-1,negative regulation of viral genome replication,and the cellular components included cytoplasm,nucleoplasm,nucleus,cytosol,adhesion,Golgi apparatus,endoplasmic reticulum membrane,while molecular functions included protein binding,RNA binding,chemokine activity,identical protein binding,and cytokine activity.KEGG pathways included TNF signaling pathway,herpes simplex virus 1 infection,NOD-like receptor signaling pathway,interaction between viral proteins and cytokines and cytokine receptors,lipid and atherosclerosis,and cytokine-cytokine receptor interaction.(3)In the proteomic analysis of lung tissues from a silica-induced pulmonary fibrosis rat model and a healthy control group,this study identified 210 differentially expressed proteins,including 137 upregulated and 77 downregulated proteins.KEGG enrichment analysis showed that the differentially expressed proteins were associated with longevity pathways,viral myocarditis,myocardial contraction,and peroxidase.The upregulated genes were mainly concentrated in the pathways of cell apoptosis,lysosome,longevity,and cell cycle,while the downregulated genes were mainly concentrated in the pathways of toxic myocarditis,myocardial contraction,tight junctions,and adrenergic receptor signaling.Through bioinformatics analysis,this study found that the ERK-MAPK signaling pathway was commonly expressed in genomics and metabolomics.GO analysis showed that the expression difference of the muscle calcium protein complex was the most significant in cell components.The molecular function was more obvious in the binding of muscle calcium protein I.Biological function showed that the difference in the synthesis pathway of peroxidase was the most obvious.By intersecting the upregulated protein sites that underwent homologous transformation with the downregulated results in method(2),14 intersecting sites were found.GO and KEGG analysis of intersecting genes showed that the biological processes were mainly focused on blood pressure regulation,positive regulation of sprouting angiogenesis,determination of left-right symmetry,hematopoiesis,and locomotor behavior.The cell components were mainly focused on cytoplasmic vesicles and mitochondria,and the molecular function was mainly focused on protein binding.The KEGG pathway was mainly focused on human papillomavirus infection and ECM-receptor interaction.The online analysis of the String website showed that the correlation between COL1A2 and ITGA5 was closer.(4)The main action sites of the intersection of the proteinomic analysis in the bronchoalveolar lavage fluid of silicosis patients were detected using RT-q PCR,and Masson staining and transmission electron microscopy were used to observe and analyze the lung tissue of silicosis-induced rats.The results showed that the proliferation of myofibroblasts was more pronounced in rats with low uric acid levels in Masson staining,while it was significantly weakened in rats with high uric acid levels,and a large amount of fibronectin deposition was found in the silica model group.Transmission electron microscopy showed that the number of cytoplasmic vesicles in macrophages in the lung tissue of silicosis rats in the low uric acid group was significantly higher than that in the high uric acid group.When COL1A2 and ITGA5 m RNA in the bronchoalveolar lavage fluid cells of silicosis patients were detected using RT-q PCR,it was found that the m RNA levels of COL1A5 and ITGA5 were lower in the high uric acid group than in the low uric acid group.CONCLUSION(1)Uric acid is a protective factor for staging of silicosis patients,and patients with higher levels of uric acid have a milder course of silicosis.(2)Clinical guidelines suggest that the level of uric acid in patients with uncomplicated hyperuricemia can inhibit the formation of silicosis fibrosis.(3)The mechanism by which uric acid reduces pulmonary fibrosis in the development stage of silicosis is related to macrophages.(4)Uric acid can inhibit the expression levels of COL1A2 and ITGA5 m RNA in macrophages,which can contribute to the reduction of lung fibrosis in silicosis. |
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