1.Research progress of chitinase 3-like protein 1 in the pathogenesis of pulmonary fibrosis
China Occupational Medicine 2024;51(5):592-597
Pulmonary fibrosis is an end-stage alteration of lung diseases characterized by fibroblast proliferation and accumulation of extracellular matrix with inflammatory damage and tissue structure destruction. The pathogenesis of pulmonary fibrosis has not been fully defined. Chitinase 3-like protein 1 (CHI3L1) plays an important role in various fibrotic diseases characterized by inflammation and tissue remodeling. During the development of pulmonary fibrosis, CHI3L1 promotes the release of inflammatory factors by binding to receptors such as chemoattractant receptor homologous molecule expressed on T-helper type-2 cells, interleukin (IL) -13 receptor subunit alpha-2, and galectin-3. CHI3L1 facilitates pulmonary fibrosis by modulating the levels of transforming growth factor-beta 1 and IL-18. Additionally, CHI3L1 contributes to pulmonary fibrosis by participating in immune responses mediated by multiple cytokines and inflammatory factors, and directly facilitate pulmonary fibrosis by mediating the activity of pulmonary fibroblasts and alveolar macrophages. Moreover, CHI3L1 can serve as a biomarker for the diagnosis and treatment for lung diseases. However, specific therapeutic targets for CHI3L1 in pulmonary fibrosis remain unavailable. Future research should aim to identify unknown specific receptors or ligands for CHI3L1 and investigate its functions in various physiological and pathological responses.
2.Effects of malathion on testicular spermatogenic function in rats.
Xiao GENG ; Cunxiang BO ; Guizhi HAN ; Hua SHAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(3):180-185
OBJECTIVETo investigate the effects of malathion on the testicular spermatogenic function of male rats and its working mechanism.
METHODSForty specific pathogen-free male Wistar rats were randomly and equally divided into four groups: three exposure groups and a control group. Malathion was administered orally to male rats in the exposure groups at 33.75, 54, and 108 mg/kg (1/32 LD₅₀, 1/20 LD₅₀, and 1/10 LD₅₀) for 60 days. Rats in the control group received an equal volume of water. The body weights of rats were measured after exposure. The organ weights and coefficients of the testes and epididymes were determined as soon as rats were sacrificed. The sperm motility, counts, and malformation rates were measured in the left epididymis. Histopathological changes, cell apoptosis, and the expression levels of Bcl-2/Bax in the testes of rats were observed using HE staining, terminal deoxynucleotidyl transferase-mediated dUPT-biotin nick end labeling, and immunohistochemistry SABC method.
RESULTSThe body weights and the testis weights in the exposure groups were significantly lower than those in the control group (P < 0.01). The exposure groups had significantly lower sperm motility and significantly higher sperm malformation rates than the control group (P < 0.01). The sperm counts were significantly lower in the exposure groups than in the control group (P<0.01). The sperm counts and motility were negatively correlated with exposure dose (r = -0.81, P < 0.01; r = -0.51, P < 0.01), while the sperm malformation rate was positively correlated with exposure dose (r = 0.85, P 0.01). The exposure groups had significantly higher spermatogenic cell apoptosis rates than the control group (P<0.01). The expression level of Bax was significantly higher in the exposure groups than in the control group (P<0.01), while the expression level of Bcl-2 was significantly lower in the exposure groups than in the control group (P < 0.01). Histopathological examination of the testes showed degenerative changes in the seminiferous tubules at various doses along with the increase in malathion exposure dose.
CONCLUSIONMalathion affects the testicular spermatogenic function of male rats and its working mechanism may involve cell apoptosis induced by down-regulation of Bcl-2 and up-regulation of Bax.
Animals ; Apoptosis ; drug effects ; Dose-Response Relationship, Drug ; Down-Regulation ; Epididymis ; Malathion ; toxicity ; Male ; Organ Size ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Sperm Motility ; Spermatogenesis ; drug effects ; Spermatozoa ; Testis ; drug effects ; Up-Regulation ; bcl-2-Associated X Protein ; metabolism
3.Effects of malathion on testicular enzyme activities and sperm quality of male rats
Xiao GENG ; Cunxiang BO ; Hua SHAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2016;34(5):329-332
Objective The aim of this study is to investigate the effects of sub chronic exposure to malathion on testicular enzyme activities and sperm quality of male rats.Methods Forty male rats were divided into four groups:three exposure groups and a control group.Malathion was administered orally to male rats at 0,33.75,54.00,and 108.00 mg/kg for 60 days to evaluate the toxic alterations in sperm dynamics and testicular enzyme activities including ACP,LDH,SDH and γ-GT.The control rats were administered with an equivalent volume of distilled water in the same manner.After sacrificed,the testes were collected and weighed.Results The body weight and the testis weight of animals showed a decreasing tendency,and there was a statistical difference between the 54.00,108.00 mg/kg groups,and the control group (P<0.05).Malathion brought about marked reduction in testicular sperm counts,sperm motility,and significant growth of sperm malformation rate in 108.00 mg/kg group.A significant decrease in the activities of testicular enzyme ACP and γ-GT was observed in malathion exposed rats,while the activities of LDH was significant increased and there were no obvious effects on the activities of SDH.The activities of ACP,γ-GT and LDH showed a statistical difference between the 108.00 mg/kg groups,and the control group.Conclusion Malathion reduced the sperm counts and sperm motility,increased the malformation rate and reduced the activities of testicular enzymies of male rats.
4.Effects of malathion on testicular enzyme activities and sperm quality of male rats
Xiao GENG ; Cunxiang BO ; Hua SHAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2016;34(5):329-332
Objective The aim of this study is to investigate the effects of sub chronic exposure to malathion on testicular enzyme activities and sperm quality of male rats.Methods Forty male rats were divided into four groups:three exposure groups and a control group.Malathion was administered orally to male rats at 0,33.75,54.00,and 108.00 mg/kg for 60 days to evaluate the toxic alterations in sperm dynamics and testicular enzyme activities including ACP,LDH,SDH and γ-GT.The control rats were administered with an equivalent volume of distilled water in the same manner.After sacrificed,the testes were collected and weighed.Results The body weight and the testis weight of animals showed a decreasing tendency,and there was a statistical difference between the 54.00,108.00 mg/kg groups,and the control group (P<0.05).Malathion brought about marked reduction in testicular sperm counts,sperm motility,and significant growth of sperm malformation rate in 108.00 mg/kg group.A significant decrease in the activities of testicular enzyme ACP and γ-GT was observed in malathion exposed rats,while the activities of LDH was significant increased and there were no obvious effects on the activities of SDH.The activities of ACP,γ-GT and LDH showed a statistical difference between the 108.00 mg/kg groups,and the control group.Conclusion Malathion reduced the sperm counts and sperm motility,increased the malformation rate and reduced the activities of testicular enzymies of male rats.
5. Lung fibrosis and changes in autophagy-related proteins in rats exposed to silica dust
Yuting YANG ; Yu ZHANG ; Gongchang YU ; Yujun CHEN ; Cunxiang BO ; Qiang JIA ; Hua SHAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2018;36(12):890-895
Objective:
To explore the changes in the autophagy marker microtubule-associated protein 1 light chain 3 (LC3) and yeast autophagy-related gene 6 (Beclin1) in rat lungs exposed to free silica (SiO2) dust for different periods.
Methods:
A total of 72 male specific pathogen-free Wistar rats were randomly divided into solvent control group and SiO2 model group. The SiO2 model group received one-time non-exposed intratracheal instillation of suspension of SiO2 particles to establish a model of silicosis. The solvent control group received an equal amount of saline. Six rats each were sacrificed at 1, 7, 14, 21, 28, and 60 days after model establishment. The pathological changes and fibrosis of rat lungs at different time points were evaluated by H&E staining and Masson staining, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of transforming growth factor-β (TGF-β) , interleukin-1 (IL-1) , and tumor necrosis factor-α (TNF-α) in lung tissue homogenate. Western blot was used to determine the relative expression levels of LC3 and Beclin1 in the lung tissue.
Results:
The results of H&E staining showed that the model group had continuous inflammation in the lung tissue from day 1 to day 60, and the inflammatory scores were significantly higher in the model group than in the control group (
6. The changes of ROR-γt,IL-17A and Foxp3 mRNA expression and promoter methylation in TDI-induced mouse asthma
Xiaoqun WANG ; Qiang JIA ; Zhenling ZHANG ; Gongchang YU ; Yu ZHANG ; Cunxiang BO ; Zhifeng YANG ; Hua SHAO
China Occupational Medicine 2017;44(01):7-13
OBJECTIVE: To explore the changes of retinoic acid related orphan receptor-γt( ROR-γt),interleukin( IL)-17 A and forkhead / winged helix protein 3( Foxp3) mRNA expression and promoter methylation in the process of asthma induced by toluene-diisocyanate( TDI). METHODS: Specific pathogens free grade healthy male BALB / c mice were randomly assigned into asthma group and control group with 18 animals in each group. In the asthma group,the mice were sensitized with 0. 30% TDI( mass-volume concentration) dropped on the dorsum of both ears( 20 μL / ear) on day 1 and day 8. On day 15,the mice were challenged with 20 μL 0. 01% TDI( mass-volume concentration) by the trachea. The control group mice were sensitized and challenged by the same procedures with the same amount of solvent( acetone / olive oil). The mice were challenged 24 hours,the pathological changes of trachea and lung tissues were observed. The bronchoalveolar lavage fluid( BALF) from each group was collected,and the inflammatory cells in BALF were counted and classified. IL-4and Interferon-γ( IFN-γ) levels in BALF supernatant were measured by enzyme-linked immunosorbent assay. ROR-γt,IL-17 A and Foxp3 mRNA expression in the lung tissue were measured by real-time fluorescent quantitative polymease chain reaction. The degree of ROR-γt,IL-17 A and Foxp3 promoter methylation in lung issue were detected by Mass Array system.RESULTS: The asthmatic group demonstrated the symptoms of acute asthma,such as breathing deeply and fastly,bowing the back,lifting the forelimbs,et al. But the control group had no such symptoms in mice. Hematoxylin-Eosin staining showed obvious inflammatory lesions in the trachea and lung tissue of asthmatic mice. Compared with the control group,the white blood cell count,the neutrophil and eosinophil percentages in BALF,the IL-4,IFN-γ levels in BALF supernatant in asthma group were all significantly increased( P < 0. 01),meanwhile the lymphocyte and monocyte percentages in BALF were reduced( P < 0. 01); ROR-γt mRNA expression was significantly increased( P < 0. 01),and the degree of promoter methylation from sites 3,4,5,6,8,11 and 12 was significantly reduced( P < 0. 05); IL-17 A mRNA expression was significantly increased( P < 0. 01),and the degree of promoter methylation from sites 6 and 7 was significantly reduced( P < 0. 01); Foxp3 mRNA expression was significantly reduced( P < 0. 01),and the degree of promoter methylation from sites 1 and 10 was significantly increased( P < 0. 01). CONCLUSION: Th17 / Treg cell immune imbalance occurs in asthma induced by TDI. ROR-γt,IL-17 A and Foxp3 gene promoter methylation abnormalities may be involved in Th17 / Treg cell immune imbalance.
7. Bioinformatic analysis on differentially expressed genes in rats exposed to silica dust
Shangya CHEN ; Guanqun CUI ; Qiang JIA ; Cunxiang BO ; Zhongjun DU ; Hua SHAO
China Occupational Medicine 2017;44(02):181-187
OBJECTIVE: To analyze the difference in gene expression profiles and screen silicosis development related differentially expressed genes(DEGs) and signaling pathways in peripheral blood specimens of rats exposed to silica dust using bioinformatics and gene chip. METHODS: GSE27023 gene expression profiles of peripheral blood samples of rats exposed to silica dust were downloaded from Gene Expression Omnibus database. After screening of the DEGs through paired-sample t-test and fold change method,DEGs related to rats exposed to silica dust was performed by Gene Ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. The protein-protein interaction(PPI) network was constructed with the Search Tool for the Retrieval of Interacting Genes database and visualized using the software Cytoscape. RESULTS: Of the 2 767 DEGs screened,1 363 were up-regulated and1 404 were down-regulated. KEGG pathway enrichment analysis showed that 39 signaling pathways,such as the calcium signaling pathway,neuroactive ligand-receptor interaction,Ras-related protein 1 signaling pathway,were significantly enriched. DEGs enrichment and significance reached the highest level in the calcium signaling pathway. PPI network and module analysis suggested that mitogen-activated protein kinase 14(Mapk14),DNA-directed RNA PolymeraseⅡ,V-erb-a erythroblastic leukemia viral oncogene homolog 4,B-cell lymphoma-2(Bcl-2),receptor interacting serine/threonine kinase 4,PH domain leucine-rich repeat protein phosphatase 2,DNA-directed RNA polymerase Ⅲ,neurogenic locus notch homolog protein 1,histone deacetylase 1,yeast switch in mating type/Sucrose non fermentation related,matrix associated,actin dependent regulator of chromatin,subfamily a,member 4 were top 10 hub-proteins. Mapk14 had the highest node degree in up-regulated DEGs,and Bcl-2 had the highest node degree in down-regulated DEGs. CONCLUSION: We found 39 signaling pathways and 10 DEGs that are related to toxicity caused by exposure to silica dust in rats by analysis of peripheral blood gene chip data. Among them,calcium signaling pathway,Mapk14 and Bcl-2 may play important roles in the development and progress of silicosis in rats.
8.A comparative study on short-term outcomes of Da Vinci robotic versus laparoscopic and open surgery for locally advanced Siewert type Ⅱ and Ⅲ adenocarcinoma of esophagogastric junction
Cunxiang LIAO ; Qing FENG ; Ping′ang LI ; Feng QIAN ; Yongliang ZHAO ; Yingxue HAO ; Bo TANG ; Jun CHEN ; Yan WEN ; Peiwu YU ; Yan SHI
Chinese Journal of Digestive Surgery 2020;19(6):620-629
Objective:To investigate the short-term outcomes of Da Vinci robotic versus laparoscopic and open surgery for locally advanced Siewert type Ⅱ and Ⅲ adenocarcinoma of esophagogastric junction (AEG).Methods:The propensity score matching and retrospective cohort study was conducted. The clinicopathological data of 404 patients with locally advanced Siewert type Ⅱ and Ⅲ AEG who underwent radical gastrectomy in the First Hospital Affiliated to Army Medical University from January 2009 to April 2019 were collected. There were 331 males and 73 females, aged from 34 to 90 years, with a median age of 62 years. Of the 404 patients, 104 undergoing Da Vinci robotic radical gastrectomy were allocated into robotic group, 205 undergoing laparoscopic radical gastrectomy were allocated into laparoscopic group, and 95 undergoing open radical gastrectomy were allocated into open group. Observation indicators: (1) the propensity score matching conditions and comparison of general data among the three groups after propensity score matching; (2) surgical situations; (3) intraoperative lymph node dissection; (4) postoperative situations; (5) postoperative complications; (6) follow-up. Patients were followed up at postoperative 1 month by outpatient examination and telephone interview to detect survival and severe complications up to June 2019. The propensity score matching was used to perform 1∶2∶1 nearest neighbor matching by SPSS 23.0 and R software 3.6.1 Matchit among the robotic group, laparoscopic group and open group. Measurement data with normal distribution were represented as Mean± SD, and comparison among groups was done using one-way ANOVA analysis. Measurement data with skewed distribution were represented as M (range), and comparison was done using the Kruskal-Wallis H test. Comparison of ordinal data was analyzed using the Mann-Whitney U test. Count data were represented as absolute numbers or percentages, and comparison among groups was done using the chi-square test. Results:(1) The propensity score matching conditions and comparison of general data among the three groups after propensity score matching: 312 of 404 patients had successful matching, including 78 in the robotic group, 156 in the laparoscopic group, and 78 in the open group. The age, cases in G1, G2, G3 (histopathological classification) and cases with proximal gastrectomy or total gastrectomy (surgical resection range) before matching were (62.2±1.0)years, 0, 37, 67, 13, 91 in the robotic group, (60.9±8.1)years, 0, 98, 107, 31, 174 in the laparoscopic group, and (58.5±9.8)years, 1, 32, 62, 27, 68 in the open group, showing significant differences among the three groups ( F=4.269, 6.356, χ2=10.416, P<0.05). The above indicators after matching were (61.2±10.8)years, 0, 28, 50, 12, 66 in the robotic group, (60.7±8.0)years, 0, 56, 100, 25, 131 in the laparoscopic group, and (60.7±8.4)years, 0, 25, 53, 18, 60 in the open group, showing no significant difference among the three groups ( F=0.074, 0.379, χ2=2.141, P>0.05). (2) Surgical situations: the surgical time, volume of intraoperative blood loss, length of surgical incision, length of proximal margin after matching were 300.0 minutes(range, 188.0-420.0 minutes), 137.5 mL(range, 50.0-400.0 mL), 6.0 cm(range, 3.0-12.0 cm), 2.5 cm(range, 1.5-5.5 cm) in the robotic group, 276.0 minutes(range, 180.0-400.0 minutes), 150.0 mL(range, 40.0-800.0 mL), 6.0 cm(range, 3.0-12.0 cm), 3.0 cm(range, 1.0-5.0 cm) in the laparoscopic group, and 244.5 minutes(range, 125.0-461.0 minutes), 200.0 mL(range, 55.0-800.0 mL), 20.0 cm(range, 18.0-25.0 cm), 2.0 cm(range, 1.0-5.5 cm) in the open group, showing significant differences among the three groups ( χ2=27.619, 30.069, 179.367, 11.560, P<0.05). (3) Intraoperative lymph node dissection: the number of lymph node dissected, the number of lymph node dissected in the first station, the number of diaphragmatic and periesophageal lymph node dissected were 30.5(range, 10.0-70.0), 18.0(range, 6.0-42.0), 4.0(range, 0-13.0) in the robotic group, 29.0(range, 12.0-79.0), 19.0(range, 6.0-47.0), 5.0(range, 0-15.0) in the laparoscopic group, and 29.0(range, 18.0-58.0), 18.0(range, 12.0-38.0), 5.0(range, 0-8.0) in the open group, showing no significant difference among the three groups ( χ2=3.676, 1.014, 0.827, P>0.05). The number of lymph node dissected in the second station, the number of lymph node dissected in the superior pancreatic region, the number of No.110 lymph node dissected, the number of No.111 lymph node dissected after matching were 9.0(range, 2.0-30.0), 9.0(range, 2.0-30.0), 1.0(range, 0-4.0), 0(range, 0-3.0) in the robotic group, 6.5(range, 0-25.0), 7.0(range, 0-25.0), 0(range, 0-3.0), 0(range, 0-4.0) in the laparoscopic group, and 6.5(range, 0-19.0), 6.5(range, 0-19.0), 0(range, 0-1.0), 0(range, 0-1.0) in the open group, showing significant differences among the three groups ( χ2=19.027, 24.368, 19.236, 11.147, P<0.05). (4) Postoperative situations: the time to first flatus, time to initial out-of-bed activities, duration of postoperative hospital stay, treatment expenses after matching were 3 days(range, 2-5 days), 2 days(range, 1-4 days), 9 days(range, 5-20 days), 10.6×10 4 yuan [range, (5.4-18.0)×10 4 yuan] in the robotic group, 3 days(range, 2-8 days), 2 days(range, 1-7 days), 9 days(range, 6-56 days), 8.6×10 4 yuan[range, (5.7-40.8)×10 4 yuan] in the laparoscopic group, and 4 days(range, 2-10 days), 4 days(range, 2-10 days), 11 days(range, 8-41 days), 8.4×10 4 yuan[range, (5.8-15.2)×10 4 yuan] in the open group, showing significant differences among the three groups ( χ2=28.487, 95.069, 39.443, 83.899, P<0.05). (5) Postoperative complications: the incidence of overall complications, incidence of severe complications (Clavien-Dindo classification ≥grade 3), incidence of gastrointestinal complications, incidence of incisional complications, incidence of respiratory complications, incidence of infection were 21.8%(17/78), 5.1%(4/78), 10.3%(8/78), 1.3%(1/78), 7.7%(6/78), 2.6%(2/78) in the robotic group, 21.8%(34/156), 7.1%(11/156), 5.1%(8/156), 1.3%(2/156), 11.5%(18/156), 3.8%(6/156) in the laparoscopic group, and 29.5%(23/78), 6.4%(5/78), 9.0%(7/78), 2.6%(2/78), 14.1%(11/78), 2.6%(2/78) in the open group, showing no significant difference among the three groups ( χ2=1.913, 0.321, 2.394, 0.866, 1.641, 0.335, P>0.05). (6) Follow-up: 312 patients after propensity score matching were follow up at postoperative 1 month. During the follow-up, 2 cases with severe complications died after discharge. No severe complication such as obstruction of input or output loop, dumping syndrome was found in the other 310 patients. Conclusions:The Da Vinci robotic radical gastrectomy is safe and feasible for locally advanced Siewert type Ⅱ and Ⅲ AEG. Compared with laparoscopic and open radical gastrectomy, Da Vinci robotic radical gastrectomy has more advantages in the number of lymph node dissected in the second station (especially in the superior pancreatic region).
9. Toluene diisocyanate induces inflammatory response and autophagy in human bronchial epithelial cells
Yujun CHEN ; Yu ZHANG ; Gongchang YU ; Yuting YANG ; Linlin SAI ; Cunxiang BO ; Qiang JIA
China Occupational Medicine 2019;46(01):1-7
OBJECTIVE: To investigate the effect of toluene diisocyanate(TDI) on the activation of autophagy and expression of inflammatory cytokines interleukin(IL)-4 and IL-6 in normal human bronchial epithelial cells(16 HBE). METHODS: i) We prepared TDI-human serum albumin(HSA) and determined the mass concentration of TDI in TDI-HSA. ii) The cells were treated with TDI-HSA and HSA at concentrations of 0.00-400.00 mg/L for 12 hours. CCK-8 assay was used to determinate the cell viability, and TDI-HSA and HSA doses were selected for subsequent experiments. iii) The cells were treated with TDI-HSA and HSA at doses of 0.00-120.00 mg/L for 12 hours, and the levels of reactive oxygen species(ROS) in the cells were detected by flow cytometry. The levels of IL-4 and IL-6 in the cell supernatant were measured by enzyme-linked immunosorbent assay. iv) The cells were treated with TDI-HSA at doses of 0.00-120.00 mg/L for 12 hours, and the autophagy activity was observed under transmission electron microscope. Western blot was utilized to detect the expression of Beclin1, microtubule-associated protein 1 light chain(LC3β) and P62. RESULTS: i) The mass concentrations of TDI in 40.00, 80.00 and 120.00 mg/L TDI-HSA groups were 0.44, 0.89 and 1.33 mg/L respectively. ii) The results of CCK-8 showed that TDI-HSA and HSA at doses below 120.00 mg/L did not affect cell viability, and 0.00-120.00 mg/L was selected as the TDI-HSA and HSA treatment doses for subsequent experiments. iii) The level of ROS in cells and the levels of IL-4 and IL-6 in the supernatant of 16 HBE cells in the TDI-HSA group at 40.00, 80.00, and 120.00 mg/L were higher than that in HSA group at the same dose(P<0.01). The level of ROS in cells and the levels of IL-4 and IL-6 in the supernatant of 16 HBE cells increased with the increase of TDI-HSA doses(P<0.01). iv) Transmission electron microscopy showed that the number of autophagic lysosomes in 16 HBE cells increased significantly, and the number of mitochondrial vacuoles increased in 40.00, 80.00, 120.00 mg/L TDI-HSA group compared with 0.00 mg/L group. With the increase of TDI-HSA dose, the relative expression of Beclin1 protein and LC3β-Ⅱ/Ⅰ ratio in 16 HBE cell supernatant increased(P<0.05), and the relative expression of P62 protein decreased(P<0.05). CONCLUSION: TDI-HSA induces increased expression of ROS and inflammatory factors and induces autophagy activation in 16 HBE cells. Autophagy may be an important factor for the development of airway inflammation in TDI-induced occupational asthma.
10.Intervention effect of apocynin on silicosis induced by silica in rats
Fang LIU ; Qiang JIA ; Ming LI ; Zhaoyuan SONG ; Chenyang HU ; Cunxiang BO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2023;41(10):801-807
Objective:To investigate the intervention effect and its mechanism of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) on silicosis induced by silica (SiO 2) in rats. Methods:In October 2021, 24 SPF SD male rats were divided into control group, silicosis model group and apocynin intervention group according to random number table method, with 8 rats in each group. SiO 2 was exposed by one-time intratracheal instillation. The rats in the apocynin intervention group were intraperitoneally injected with apocynin 50 mg/kg, 3 times a week, on the second day after treatment. The rats were sacrificed 28 days later, and lung coefficients were calculated after lung tissues were weighed. Hematoxylin-eosin staining and Masson staining were used to observe the lung histopathological changes in each group, respectively. The levels of NOX, reactive oxygen species (ROS), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in lung tissue were detected. The expressions of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The level of hydroxyproline (HYP) was detected by alkaline hydrolysate. The expressions of transforming growth factor beta 1 (TGF-β1), E-cadherin (E-cad) and α-smooth muscle actin (α-SMA) in lung tissue were detected by Western blotting. Results:Compared with the control group, the body weight of silicosis model group was decreased, the lung tissue showed obvious inflammatory infiltration and fibrosis, and the levels of lung coefficient, IL-1β, IL-6, TNF-α and TGF-β1 were significantly increased ( P<0.05). Compared with the silicosis model group, the lung tissue injury in the apocynin intervention group was significantly improved, the lung coefficient, NOX, ROS, MDA, IL-1β, IL-6, TNF-α and TGF-β1 levels were decreased, and the activity of GSH-Px was increased ( P<0.05). Compared with the silicosis model group, the expressions of HYP and α-SMA were decreased and the level of E-cad was increased in the apocynin intervention group ( P<0.05) . Conclusion:Apocynin may alleviate SiO 2-induced fibrosis in silicosis rats by reducing oxidative stress, the release of inflammatory factors and inhibiting the process of epithelial-mesenchymal transition.