Intervention effect of miR-204-3P on silica dust-induced silicosis fibrosis in rats / 环境与职业医学

Background Long-term exposure to free silica particles will lead to fibrosis of lung tissue, and abnormal expression of microRNA (miRNA) may affect the occurrence and process of fibrosis. Objective To observed possible intervention effect of miR-204-3p overexpression adenovirus on silicosis fibrosis induced by silica dust using a silicosis rat model via non-exposed intratracheal instillation. Methods Forty SD rats were randomly divided into four groups: control group, silicosis model group, miRNA-NC group, and miR-204-3p intervention group. Under ether anesthesia, rats in the silicosis model group, miRNA-NC group, and miR-204-3p intervention group were injected with 1 mL (50 mg·mL−1) of free silica dust suspension into the trachea, while the control group was injected with the same volume of normal saline. After 30 d of dust exposure, the miR-204-3p intervention group was injected with rno-mir-204 adenovirus vector to overexpress miR-204-3p, and the miRNA-NC group was given empty virus vector. After 30 d of normal feeding, the animals were sacrificed by chloral hydrate anesthesia, and the lung tissue was taken for subsequent experiments. The relative expression level of miR-204-3p in lung tissue of rats in each group was detected by real-time fluorescence quantitative PCR (RT-qPCR). HE staining, Masson staining, and Sirius red staining were used for pathological observation. Immunohistochemistry was used to detect the expression of Fibronectin and Collagen I in lung tissue of rats in each group. RT-qPCR was used to detect the relative gene expression levels of fibrosis markers Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in each group. Western blot was used to detect the protein expression levels of fibrosis markers Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in each group. Results The anatomical features of lung tissue in the control group were pink lung tissue with soft texture and smooth surface, while those in the silicosis model were grayish white tissue with hard texture and scars and grayish white silicon nodules on the surface. Compared with the silicosis model group, the color of lung tissue in the miR-204-3p intervention group became ruddy, the surface was smooth, and the texture became soft. The staining results showed that the alveolar wall of the control group was thin, there were a small number of capillaries in the alveoli, and the alveolar structure was clear and complete. In the silicosis model group, the alveolar wall became thicker, the pulmonary septum was partially broken, the alveolar structure was defective, and a large amount of collagen fibers were deposited. The alveolar structure of the miR-204-3p intervention group was relatively clear and there was a small amount of collagen fiber deposition. RT-qPCR results showed that compared with the control group, the relative expression levels of miR-204-3p in lung tissue of the silicosis model group and the miRNA-NC group were decreased (P<0.05), and the relative expression level of miR-204-3p in lung tissue of the miR-204-3p intervention group was increased (P＜0.05). The results of immunohistochemistry showed that compared with the control group, the expression levels of Fibronectin and Collagen I in lung tissue of the silicosis model group were increased (P＜0.05). Compared with the silicosis model group, the relative expression levels of Fibronectin and Collagen I in lung tissue of the rats in the miR-204-3p intervention group were significantly decreased (P<0.05). The results of RT-qPCR and Western blot showed that compared with the control group, the relative protein and gene expression levels of fibrosis factors Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of the silicosis model group increased (P＜0.05). Compared with the silicosis model group, the relative gene and protein expression levels of fibrosis factors Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in the miR-204-3p intervention group were decreased (P＜0.05). Conclusion Silica dust can cause lung fibrosis in rats, and overexpression of miR-204-3P in vivo can reduce silicosis fibrosis in rats caused by silica dust.

Characterization and correlation analysis of lung flora in rats with silica-induced acute lung injury / 中国病理生理杂志

AIM:To elucidate the possible biological mechanism of silica-induced acute lung injury in rats.METHODS:Sixteen Male Sprague-Dawley rats were divided into control and acute silicosis model groups,and instilled intratracheally with 1 mL of normal saline and 50 g/L silica suspension,respectively.After 7 d,the rats were sacrificed for collection of lung tissue and serum.The serum levels of interleukin-1β(IL-1β),IL-18 and tumor necrosis factor-α(TNF-α)were measured by using ELISA.The protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)and gasdermin D(GSDMD)were measured by immunohistochemistry.Bacterial DNA was ex-tracted from the lung tissue for 16S ribosomal RNA gene sequencing to characterize changes in the composition of lung flo-ra.The differences in the structure of bacterial flora between control and model groups were analyzed by bioinformatic analy-ses.RESULTS:Immunohistochemical analysis showed that the protein expression levels of NLRP3 and GSDMD were higher in the lungs of the rats in model group.In addition,serum cytokine profiling showed that IL-1β,IL-18 and TNF-α levels were significantly higher in model group.The most abundant bacterial genera in the lung flora of the rats in model group were Bifidobacterium,Clostridium sensu stricto 1,and Parasutterella.The NLRP3 and GSDMD levels in the lung tissue and IL-1β and TNF-α levels in serum were positively correlated with the abundance of Parasutterella.CONCLU-SION:The alterations in lung flora structure and increased inflammation levels may be the actual biological mechanisms underlying silica-induced acute lung injury.The modulation of lung flora may provide a basis for the prevention and treat-ment of silica-induced acute lung injury.

Effects of different concentrations of brusatol on silicosis fibrosis in mice / 环境与职业医学

Background Silicosis is a diffuse fibrosis of the lungs caused by long-term inhalation of free silicon dioxide (SiO2). It has a complex pathogenesis and lacks effective treatment. Brusatol (Bru) has a variety of biological activities, and its role in silicosis fibrosis is unclear yet. Objective To investigate the effects of different concentrations of Bru on SiO2-induced silicosis fibrosis in mice. Methods Thirty male C57BL/6J mice were randomly divided into five groups: a control group, a silica group, and three Bru intervention groups with low, medium, and high doses (1, 2, and 4 mg·kg−1), with 6 mice in each group. Except the control group, the remaining groups were established as SiO2-induced silicosis mouse models by using a single tracheal infusion of 50 μL 60 mg·mL−1 SiO2 suspension. The control group was dosed with equal amount of saline. The Bru intervention groups were injected intraperitoneally with Bru for 5 consecutive days and then injected every other day. After 28 d of exposure, the mice were executed and lung tissues were collected. The lung coefficient of the mice was measured, and the pathological changes of the lung tissues were observed after hematoxylin-eosin (HE) and Masson staining. The levels of apoptotic protein Cleaved-caspase 3, fibrosis-related protein α-smooth muscle actin (α-SMA), type I collagen (Col-I), autophagy-associated protein Beclin1, microtubule-associated protein 1 light chain 3 (LC3), Sequestosome 1 (p62/SQSTM1), Kelch like ECH-associated protein-1 (Keap1), and nuclear factor erythroid 2 related factor 2 (Nrf2) were detected by Western blot. The mRNA levels of Caspase 3, α-SMA, and Col-I were measured by realtime fluorescence-based quantitative PCR. Results Compared with the control group, the lung coefficient of mice in the silica group was significantly increased (P < 0.01); the lung tissues of the silicosis mice showed damaged alveolar walls, along with infiltration of inflammatory cells, fibrous nodules, and collagen deposition; furthermore, the protein and mRNA levels of Cleaved-caspase 3, α-SMA, and Col-I were significantly increased (P < 0.01); the expression levels of Beclin1, LC3-II/I, p62, and Nrf2 were increased, while that of Keap1 was decreased (P < 0.05). The interventions with low and medium doses of Bru reduced lung coefficient (P < 0.05) and protected against pathological damage and collagen deposition in the lung tissues of the silicosis mice; the protein and mRNA expression levels of Cleaved-caspase 3, α-SMA, and Col-I were significantly decreased in the low and medium dose groups (P < 0.05, P < 0.01), the expression levels of Beclin1, LC3-II/I, p62, and Nrf2 were also decreased (P < 0.05, P < 0.01), and the expression level of Keap1 was increased in the medium dose group (P < 0.05). However, compared with the silica group, the differences in lung coefficient, pathological damage, and protein and mRNA expression levels of Cleaved-caspase 3, α-SMA, and Col-I in the Bru high dose group were not statistically significant (P > 0.05). In addition, the high dose of Bru decreased Beclin1, LC3-II/I, and Nrf2 expression levels (P < 0.01), did not change p62 protein expression level (P > 0.05), while increased Keap1 protein level (P < 0.01). Conclusion Low and medium doses of Bru might regulate autophagy through the Keap1-Nrf2 pathway, ameliorate autophagic degradation impairment, reduce pulmonary coefficient, attenuate apoptosis, and delay the progression of fibrosis in SiO2-induced silicosis mice.

Relationship between plasma SP-A expression level and disease stage in silicosis patients / 上海预防医学

ObjectiveTo investigate the relationship between plasma surfactant protein⁃A （SP⁃A） expression level and silicosis progression， and to provide early evidence for exploring whether SP⁃A can be used as a biomarker for clinical monitoring of silicosis disease progression. MethodsWe recruited 187 silicosis patients in Guangdong Province hospital for occupational disease prevention and treatment between November， 2019 and November，2020. Their peripheral venous blood samples were collected for the plasma isolation. The level of pulmonary SP⁃A was detected by enzyme-linked immunosorbent assay. ResultsThere was a statistically significant difference in the level of SP⁃A among the silicosis groups （P<0.05）， and the plasma SP-A level of the silicosis patients in stage Ⅲ was higher than that in stage Ⅰ and stage Ⅱ （P<0.05）. Smoking had effect on plasma SP⁃A levels， Age， working years and drinking had no effect on plasma SP⁃A levels. ConclusionThe expression level of SP⁃A in the plasma of silicosis patients is increased， which has a certain correlation with the disease stage， and plays a certain early warning role in the occurrence and development of silicosis， and may be a potential biomarker for the diagnosis and prognosis of silicosis.

Oxamate alleviates silicotic fibrosis in mice by inhibiting senescence of alveolar type II epithelial cells / 环境与职业医学

Background The senescence of alveolar type II epithelial cells is an important driving factor for the progression of silicotic fibrosis, and the regulatory effects of oxamate on the senescence of alveolar type II epithelial cells is still unclear. Objective To explore whether lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting senescence of alveolar type II epithelial cellsMethods This study was divided into two parts: in vivo experiments and in vitro experiments. In the first part, forty SPF C57BL/6J male mice were randomly divided into four groups with 10 in each group: control group, silicosis model group, low-dose oxamate treatment group, and high-dose oxamate treatment group. The silicotic mouse model was established by intratracheal instillation of 50 μL SiO2 suspension (100 mg·mL−1). The treatment models were prepared by intraperitoneal injection of 100 μL oxamate (225 mmol·L−1 and 1125 mmol·L−1). In the second part, induction of MLE-12 mouse alveolar type II epithelial cells was conducted with SiO2. The in vitro experimental groups were ① SiO2 induction groups: control group, 50 μg·mL−1 SiO2 group, 100 μg·mL−1 SiO2 group, and 200 μg·mL−1 SiO2 group, and ② oxamate treatment groups: control group, SiO2 group (100 μg·mL−1), low-dose oxamate (25 mmol·L−1) treatment group, and high-dose oxamate (50 mmol·L−1) treatment group. Pathological morphology of lung tissues was evaluated after hematoxylin-eosin (HE) staining; deposition of collagen in lung tissues was evaluated after sirius red staining; positive co-expression of prosurfactant protein C (Pro-SPC) and β-galactosidase was detected by immunofluorescence staining; positive expression of β-galactosidase in MLE-12 cells was detected by immunofluorescence staining. The protein expression levels of collagen type I (CoL I), fibronectin1 (FN1), hexokinase 2 (HK2), pyruvate kinase isozyme type M2 (PKM2), lactate dehydrogenase A (LDHA), p-ataxia telangiectasia and Rad3-related kinase (ATR), and cyclin-dependent kinase inhibitors p21, and p16 were detected by Western blotting. Results Compared with the control group, the protein expression levels of HK2, PKM2, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group and the SiO2-induced MLE-12 cells (P＜0.05). The in vivo studies showed that, compared with the control group, the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the protein expression levels of CoL I, FN1, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group (P＜0.05). Compared with the silicosis model group, the oxamate treatment groups showed significant downregulation of the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the the CoL I, FN1, LDHA, p-ATR, p21, and p16 protein expression levels, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). The in vitro studies showed that, compared with the control group, the proportion of β-galactosidase positive cells and the protein expression levels of p-ATR, p21, and p16 were significantly upregulated in the SiO2-induced group (P＜0.05). Compared with the SiO2 group, the proportion of β-galactosidase positive cells and the LDHA, p-ATR, p21 and p16 protein expression levels were significantly downregulated in the oxamate treatment groups, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). Conclusion Lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting the senescence of alveolar type II epithelial cells.

Network pharmacology reveals the effect and mechanism of Ganoderma leucocontextum ethanol extract on improving inflammatory response in silicosis lungs / 中国职业医学

ObjectiveTo explore the effect of Ganoderma leucocontextum ethanol extract (GLE) on silicosis and its potential molecular mechanism using network pharmacology, molecular docking technology and animal experiments. Methods i) The components of GLE were analyzed using ultra-performance liquid chromatography-Q Exactive-mass spectrometry (UPLC-QE-MS) method. The active components, potential molecular pathways and targets of GLE in the intervention of inflammation process of silicosis was explored using network pharmacology and molecular docking technology. ii) Specific pathogen free male C57BL6/J mice were divided into four groups with 10 mice in each group. The mice in the silicosis model group and GLE intervention group were given a dose of 80 μL silica suspension with a mass concentration of 50 g/L once by non-exposed tracheal instillation, and the mice in the blank control group and GLE control group were given an equal volume of sterile 0.9% sodium chloride solution. From the second day after modeling, GLE control group and GLE intervention group were given GLE at a dose of 200 mg/(kg•d) by gavage, while blank control group and silicosis model group were given the same volume of 0.9% sodium chloride solution by gavage, once per day for 35 days. After that, the histopathological changes of lung tissues of mice were observed, the lung mass coefficient, inflammation score and the ratio of collagen deposition area were calculated, and the levels of tumor necrosis factor (TNF) -α, interleukin (IL) -1β and IL-6 in the lung tissues of mice were detected by enzyme-linked immunosorbent assay. Results i) A total of 76 active components of GLE were detected by UPLC-QE-MS. Among them, 36 ingredients met the screening criteria of the five principles of drug-like components. A total of 67 potential targets of the 36 GLE active ingredients to improve the inflammatory response of silicosis were screened based on the network pharmacology theory. The result of Kyoto Encyclopedia of Genes and Genomes enrichment analysis and Gene Ontology functional analysis showed that IL signaling and cytokine signaling of immune cells played a key role in the process of anti-silicosis of GLE. The results of molecular docking showed that the top 10 targets based on the 67 intersection targets were TNF, IL6, B-cell lymphoma 2, cellular tumor antigen p53, Caspase-3 subunit p12, JUN, epidermal growth factor receptor, IL1B, 67 kDa matrix metalloproteinase-9 and prostaglandin G/H synthase 2. The result of protein-protein interaction analysis showed that glycyrrhetinic acid had the strongest affinity with the key targets TNF-α, IL-1β and IL-6, followed by ganoderma acid DM, alismatol C, ganoderma acid β and red sapogenin. ii) The results of histopathological examination showed that the inflammatory response and collagen deposition were alleviated in the lungs of mice with silicosis. The lung mass coefficient, inflammation score, ratio of collagen deposition area and IL-6 expression in lung were lower in mice of the GLE intervention group (all P<0.05), compared with the silicosis model group. However, there was no significant difference in the levels of TNF-α and IL-1β in lung tissues between the two groups (all P>0.05). Conclusion GLE may reduce silica-induced lung inflammation and fibrosis by inhibiting the IL-6 level in lung tissues of mice. Its mechanism is associated with the synergistic action of multi-components, multi-targets and multi-pathways.

Un caso poco frecuente: síndrome de Erasmus y tuberculosis / A rare case: Erasmus syndrome and tuberculosis

Resumen Presentamos el caso de un hombre de 35 años, are nador durante ocho años, con diagnóstico reciente de tuberculosis pulmonar y esclerosis sistémica, que ingre só por cuadro de disnea y mal estado general. Se realizó radiografía de tórax donde se evidenció neumotórax grado I, en la tomografía de tórax, también presentó masas hiperdensas confluyentes, asociadas a un patrón de neumonía intersticial no especifica (NSIP), hallazgos compatibles con silicosis pulmonar complicada. Debi do al avanzado estadio clínico, no pudieron realizarse estudios diagnósticos invasivos ni estudios de función pulmonar. Como tratamiento inicial se colocó un tubo de avenamiento pleural, se realizó tratamiento antifímico y se indicó oxigenoterapia crónica domiciliaria. Se remitió al paciente a consultorios de enfermedades intersticia les y reumatología para un manejo multidisciplinario, aunque el cuadro infeccioso contraindicó la posibilidad de un tratamiento inmunosupresor. Finalmente, el pa ciente falleció bajo cuidados paliativos. La inhalación de sílice es la causa de la silicosis, pero también está implicada en el desarrollo de la esclerosis sistémica (síndrome de Erasmus) y aunque comparten un factor de riesgo común, es raro encontrar ambas enfermedades coexistiendo. Presentamos el caso de un paciente joven donde ambas condiciones se presentaron de manera agresiva, con el objetivo de remarcar la importancia de la búsqueda activa de las enfermedades por exposición y sus condiciones asociadas.

Abstract We present the case of a 35-year-old male patient, sandblaster for eight years, recently diagnosed with pulmonary tuberculosis and systemic sclerosis, who was admitted with dyspnea and poor general condition. Chest X-ray showed a grade I pneumothorax, and on the chest tomography he presented confluent hyperdense masses associated with a pattern of non- specific in terstitial pneumonia (NSIP), findings compatible with complicated silicosis. Due to the advanced clinical stage, neither invasive diagnostic test nor pulmonary func tion test could be performed. Initial treatment included placement of a pleural drainage tube, antituberculosis treatment and chronic home oxygen. The patient was referred to the interstitial disease and rheumatology de partments for multidisciplinary management, although the infectious condition contraindicated the possibility of immunosuppressive treatment. The patient eventu ally died under palliative care. Silica inhalation is the cause of silicosis, but it is also implicated in the devel opment of systemic sclerosis (Erasmus syndrome) and although they share a common risk factor, it is rare to find both diseases coexisting. We present the case of a young patient in whom both diseases presented aggres sively, with the aim of highlighting the importance of actively searching for expositional diseases and associ ated conditions.

Research progress on role of programmed cell death in silicosis and its possible mechanisms / 环境与职业医学

Silicosis is a common occupational disease caused by long-term inhalation of large amounts of free SiO2 dust and deposition in lung tissues, characterized by the formation of silicon nodules and diffuse fibrosis of lung tissues. Silicosis is one of the most common and serious occupational diseases in China, and its treatment imposes a huge economic burden on individuals and the country. The formation mechanism of silicosis is very complex, and no early screening indicators, effective drugs, and treatment methods are available yet. The current diagnosis of silicosis is based on occupational history and chest radiography findings, and it is irreversible once pulmonary fibrosis develops. Moreover, as silicosis is a continuously progressive disease, even if silicosis patients stop exposure to free SiO2 dust, their pulmonary fibrosis will continue to develop and deteriorate. Programmed cell death (autophagy, apoptosis, ferroptosis, etc.) is a key factor involved in the development of silicosis. This article summarized the important roles of programmed cell death, including autophagy, apoptosis, and ferroptosis, in silicotic fibrosis, and concluded that regulating different programmed cell death and related signaling pathways through effective means may delay the process of silicosis fibrosis, providing new ideas and clues for exploring potential mechanisms of silicosis formation and formulating prevention and treatment strategies.

The developments of silicosis drugs / 药学学报

Pneumoconiosis is the most common occupational disease in China, which severely endangers people's health. Depending on the inhaled air pollutants, pneumoconiosis is classified as anthracosis, silicosis, asbestosis, etc., among which silicosis is the most common and serious. Silicosis is a systemic, poor prognostic disease characterized by diffuse fibrosis of lung tissue, which is caused by long-term exposure to dust with high levels of free silicon dioxide (SiO2) in the occupational environment. Appropriate treatment in time is important for the disease. Unfortunately, no effective drugs have been approved to delay or even reverse pulmonary fibrosis caused by SiO2. This review briefly classifies potent therapeutic drugs and compounds in term of mechanisms, providing the probability for clinical treatment of silicosis.

Research progress of thyroid hormone in pulmonary fibrosis / 中华劳动卫生职业病杂志

Pulmonary fibrosis is end-stage of variety of heterogeneous interstitial lung disease, characterizedby excessive proliferation of fibroblasts and extracellular matrix deposition and destruction of lung parenchyma. Thyroid and lung are derived from the same endodermal cells, thyroid hormone affect the occurrence、development and prognosis of the chronic obstructive pulmonary disease, lung cancer and other lung diseases, This article reviews the role and mechanism of thyroid hormone in pulmonary fibrosis in order to provide new idea for the study of the role and mechanism of thyroid hormone in silicosis.

Analysis of serum CA125 and related influencing factors in silicosis patients with pulmonary heart disease / 中华劳动卫生职业病杂志

Objective: To analyze the serum carbohydrate antigen 125 (CA125) level and its influencing factors in male silicosis patients with pulmonary heart disease. Methods: In October 2021, data of 38 male patients with simple silicosis (silicosis group), 28 cases of silicosis with pulmonary heart disease (pulmonary heart disease group), and 27 healthy controls (control group) in the same age group were collected in inpatient and outpatient of Nanjing Occupational Disease Prevention and Control Hospital from January 2017 to December 2020. The serum CA125 levels of the three groups were compared, and the correlation between disease-related indexes and serum CA125 in silicosis patients with pulmonary heart disease was analyzed, as well as the influencing factors of pulmonary heart disease and serum CA125 levels in silicosis patients. Results: The serum CA125 level[ (19.95±7.52) IU/ml] in pulmonary heart disease group was higher than that in silicosis group[ (12.98±6.35) IU/ml] and control group[ (9.17±5.32) IU/ml] (P<0.05). There was no significant difference in serum CA125 level between the silicosis group and the control group (P>0.05). Serum CA125 levels were positively correlated with blood uric acid and fasting blood glucose in silicosis patients with pulmonary heart disease (r=0.39, 0.46, P<0.05). Serum CA125 level was a risk factor for silicosis patients with pulmonary heart disease (OR=1.13, 95%CI: 1.02-1.24, P<0.05). Dust exposure time, lactate dehydrogenase and smoking history were positively correlated with serum CA125 level in silicosis patients (P<0.05) . Conclusion: The serum CA125 level of male silicosis patients with pulmonary heart disease is significantly increased, and the level of CA125 is correlated with the level of fasting blood glucose and blood uric acid.

Progress on pharmacological mechanism of active components of Chinese materia medica on silicosis / 环境与职业医学

By the end of 2021, a total of 915000 cases of occupational pneumoconiosis and 450000 existing cases have been reported nationwide. Silicosis is a common and serious pneumoconiosis disease caused by long-term inhalation of large amounts of free silica dust and extensive nodular fibrosis in the lungs. Because its specific pathogenic mechanism has not been elucidated and the relevant research progress is slow, there is still a lack of effective therapeutic and interventional drugs. With the increase of national attention and the unique advantages of Chinese materia medica in the treatment of silicosis, more and more studies have been conducted on the treatment of silicosis with active ingredients of Chinese materia medica in China, but most of them are still in preclinical research stage. This article mainly introduced the pharmacological action and mechanism of selected active components of Chinese materia medica in the intervention of silicosis from three aspects: anti-inflammation, anti-oxidation, and intervention of apoptosis, providing ideas for subsequent research and development of new drugs for silicosis. This article argues, it is considered that some traditional Chinese medicines must observe the pathological changes in the treatment of silicosis in the overall animal experiment, clarify their pharmacodynamic effects, and further study the multiple targets and pathways involved in them to elucidate their specific mechanisms of action. At the same time, it can strengthen the analysis of active ingredients of traditional Chinese medicine, or modify the structure of active ingredients, and then enhance its pharmacological activity in the treatment of silicosis, realizing the transformation of preclinical research stage to the results of clinical research.

Meta-analysis of Ac-SDKP inhibition of Pulmonary fibrosis in animal models / 中华劳动卫生职业病杂志

Objective: To systematically study the anti-fibrotic effect of N-acetyl-seryl-as partyl-lysyl-proline (Ac-SDKP) on pulmonary fibrosis. Methods: In May 2021, a computer search was performed on CNKI, Wanfang Knowledge Service Platform, VIP.com, China Biomedical Literature Database, Pubmed, OVID and other databases. The retrieval time was from January 2008 to May 2021. Randomized controlled experiments on the inhibition of pulmonary fibrosis by Ac-SDKP were screened. The control group was the pulmonary fibrosis model group and the experimental group was the Ac-SDKP treatment group. The quality of the literature was assessed using the syrcle risk of bias assessment tool, and data were extracted. Data analysis was Performed using revman 5.4 software. Results: 18 papers were included, with a total of 428 animal models. The results of meta analysis showed that the contents of α-smooth muscle actin (α-SMA), type I collagen, type Ⅲ collagen, transforming growth factor-β (TGF-β) and Nodule area in the exPerimental group were lower than those in the control grouP. [SMD=-2.44, 95%CI (-3.71--1.17), P=0.000][SMD=-5.36, 95%CI (-7.13--3.59), P=0.000] [SMD=-3.07, 95%CI (-4.13--2.02), P<0.000][SMD=-2.88, 95%CI (-3.63--2.14), P=0.000] [SMD=-1.80, 95%CI (-2.42--1.18), P=0.000], the content of hydroxy proline in the experimental group was higher than that in the control group [SMD=7.62, 95%CI (4.90-10.33), P=0.000], all indexes included in the literature were statistically significant. Conclusion: Ac-SDKP has obvious inhibitory effect on the process of pulmonary fibrosis, and may become a new clinical drug for the treatment of pulmonary fibrosis.

A systematic review of the epidemiology and clinical characteristics of artificial stone-related silicosis and dust protection / 中华劳动卫生职业病杂志

Objective: To investigate the epidemiology, clinical characteristics, on-site dust monitoring and individual protection of the patients with artificial stone-related silicosis. Methods: In March 2022, the literature on artificial stone-related silicosis published from January 1965 to February 2022 was searched in China Journal Full-text Database, Wanfang Database, VIP Database, EMbase and PubMed. Chinese and English search terms include "silica dust""silica dust""silicosis""artificial stone""pneumoconiosis", etc. References were included according to inclusion and exclusion criteria, and data were extracted. The epidemiological characteristics, natural course of disease, workplace dust concentration and individual protection level of patients with artificial stone-related silicosis were analyzed by systematic review. Results: A total of 30 literatures were included, including 7 cohort studies, 14 cross-sectional studies, 3 case-control studies and 6 case reports. A total of 1358 patients with artificial stone-related silicosis were diagnosed from 1997 to 2020, with an average age of 41.5 years old and an average dust exposure time of 11.3 years. Among them, 36.2% (282/778) had progressive mass fibrosis or accelerated progressive silicosis at first diagnosis. Chest imaging showed diffuse small nodule shadow, pulmonary fibrosis, and silico-alveolar proteinosis. Pulmonary function showed restricted or mixed ventilation disorder with or without decreased diffusion volume. The disease progressed rapidly, with progressive mass fibrosis, respiratory failure, and even death. Patients engaged in artificial quartz stone processing, with high concentration of silica including ultra-fine particles, most of which were dry operation, lack of on-site ventilation measures and no effective personal protection. Conclusion: The artificial stone processing workers suffer from artificial stone-related silicosis due to dry cutting, lack of on-site dust removal facilities and personal protective measures, and the disease progresses rapidly, leading to poor prognosis.

Evaluation of right ventricular function using two-dimensional speckle tracking echocardiography and analysis of the risk factors for right ventricular dysfunction in patients with silicosis / 中华劳动卫生职业病杂志

Objective: To evaluate the right ventricular function using two-dimensional speckle tracking echocardiography (2-D STE) and analyze the associated risk factors of right ventricular dysfunction in patients with silicosis. Methods: All 104 patients with silicosis treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from May 2021 to September 2022 were enrolled in this study in October 2022. The clinical information of patients such as general data, arterial blood gas analysis and pulmonary function test were collected. The right ventricular function of patients was evaluated by 2-D STE-derived right ventricular free wall longitudinal strain (RVFWLS) and conventional echocardiographic-derived parameters, including right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) and doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S'), respectively. Based on their RVFWLS, the patients were divided into right ventricular dysfunction group and normal right ventricular function group. Risk factors for right ventricular dysfunction in patients with silicosis were analyzed using binary logistic regression analysis. Results: A total of 104 silicosis patients were enrolled, with aneverage age (65.52±11.18) years old, among whom including 57 cases diagnosed with stage Ⅰ/Ⅱ silicosis and 47 cases diagnosed with stage Ⅲ silicosis. 26 (25.00%) patients concurrent right ventricular dysfunction. The abnormal rates of RVFAC, TAPSE and S' in patients were 16.35% (17 cases), 21.15% (22 cases) and 6.73% (7 cases), respectively. The RVFAC and TAPSE in right ventricular dysfunction group were lower than those in normal right ventricular function group, and the incidence of pulmonary arterial systolic pressure ≥36 mmHg was higher than that in normal right ventricular function group (P<0.05). Logistic regression analysis showed that arterial partial pressure of oxygen (OR=0.932, 95%CI: 0.885-0.981, P=0.007) was the protective factor, and the forced expiratory volume in 1 second (FEV(1)) /forced vital capacity (FVC) ratio<70% (OR=5.484, 95%CI: 1.049-28.662, P=0.044) and stage Ⅲ silicosis (OR=6.343, 95%CI: 1.698-23.697, P=0.007) were the risk factors for silicosis patients concurrent right ventricular dysfunction. Conclusion: The incidence of right ventricular dysfunction is higher in patients with stage Ⅲ silicosis than that in patients with stage Ⅰ/Ⅱ silicosis. Using 2-D STE can help the early detection of silicosis with right ventricular dysfunction. Hypoxemia, airflow limitation and the stage Ⅲ silicosis are the risk factors for silicosis patients concurrent right ventricular dysfunction.

Epidemiological characteristics of pneumoconiosis deaths in a certain area from 1961 to 2020 / 中华劳动卫生职业病杂志

Objective: To investigate the epidemiological characteristics of pneumoconiosis deaths in Putuo District of Shanghai, and to provide evidence for prevention and management of pneumoconiosis in the future. Methods: In June 2021, the data of 263 patients with pneumoconiosis who died from January 1961 to December 2020 in Putuo District of Shanghai were retrospectively analyzed. Trend χ(2) test, analysis of variance and Spearman rank correlation methods were used to analyze the basic information, age of exposure to dust, promotion period, course of disease and direct cause of death of patients with pneumoconiosis. Results: Among the 263 cases of pneumoconiosis patients who died in Putuo District of Shanghai from 1961 to 2020, 260 cases (98.86%) were male. The main types of pneumoconiosis were foundry worker pneumoconiosis (53.23%, 140/263) and silicosis (43.73%, 115/263). The main types of pneumoconiosis were sand cleaner (36.50%, 96/263). The age of onset was (53.42±10.13) years old, the age of death was (76.14±9.12) years old, and the age of exposure to dust was (20.91±8.99) years. The duration of dust exposure was negatively correlated with the duration of disease (r(s)=-0.24, P<0.001). With the increase of pneumoconiosis stage, the mortality of silicosis and foundry worker pneumoconiosis also showed an increasing trend (χ(2)(trend)=4.22, 3.87, P=0.040, 0.049). 31.94% (84/263) of pneumoconiosis patients died directly from pneumoconiosis, ranking first among the direct causes of death. Conclusion: The death cases of pneumoconiosis in Putuo District of Shanghai are mainly foundry worker pneumoconiosis and silicosis, and pneumoconiosis is the main cause of death.

The incidence of artificial stone-related silicosis among interior decoration workers in different countries / 中华劳动卫生职业病杂志

In this paper, 177 cases of artificial stone-related silicosis in interior decoration workers from Israel, Spain, USA, Italy and Australia were analyzed. Interior decoration workers were from small businesses (or workshops), engaged in kitchen and/or bathroom artificial stone countertops cutting, grinding, polishing and other reprocessing. In the working environment, the content of crystalline silica in artificial stone was more than 70%, and the concentration of silica dust exceeded the relevant standards. Most workplaces used dry cutting without ventilation and dust removal and other dust-proof measures, and most workers did not wear qualified respiratory protective equipment. Taking comprehensive measures such as wet operation, ventilation and dust removal, and individual protection can effectively prevent the occurrence of artificial stone-related silicosis.

Intervention effect of physical exercise on silicotic mice / 环境与职业医学

Background Pneumoconiosis is the most serious occupational disease in China, and silicosis accounts for about half of it. Any intervention effect of physical exercise as the key and core of lung rehabilitation training on silicosis is still unclear. Objective To explore potential intervention effect of physical exercise on silicotic mice. Methods Forty SPF C57BL/6 male mice were randomly divided into four groups, 10 in each group, including a control group, a physical exercise group, a silicosis model group, and a silicosis model + physical exercise intervention group. Silicotic mouse model was established by using 50 μL SiO2 suspension (200 mg·mL−1). A treadmill was used to prepare mice receiving physical exercise at 0° inclination, 12.3 m·min−1, 60 min·d−1, 5 d·week−1 for 4 weeks. Pathological morphology of lung tissues was evaluated after hematoxylin-eosin (HE) staining; deposition of collagen in lung tissues was evaluated after Van Gieson (VG) staining; expression of p-protein kinase R-like endoplasmic reticulum kinase (PERK) was detected by immunofluorescence staining; expressions of cyclin dependent kinase inhibitors (p21) and p-p38 mitogen activated protein kinase (p38) were detected by immunohistochemistry. The protein expressions of endoplasmic reticulum stress signal factors [p-inositol-requiring enzyme-1α (p-IRE-1α), p-PERK, and p-eukaryotic initiation factor-2α (p-eIF-2α)], senescence signal factors (p-p53, p21, and p16), mitogen-activated protein kinase (MAPK) signal factors [p-p38, p-extracellular regulated protein kinases (p-ERK), and p-stress-activated protein kinase (p-JNK)] were detected by Western blotting. Results After designed acute SiO2 exposure, the images of micro computed tomography (CT) showed high density shadows in lung tissues of the silicotic mice and less shadows in lung tissues of the physical exercise intervention mice. After HE staining, the proportions of silicotic nodule area in lung tissues was (18.67±3.89) % in the silicosis model group, and significantly decreased to (8.78±1.05) % in the silicosis model + physical exercise intervention group (P<0.05). After VG staining, the proportion of collagen fiber area of lung tissues was (10.37±2.18) % in the silicosis model group, and significantly decreased to (4.35±0.89) % in the silicosis model + physical exercise intervention group (P<0.05). The results of immunofluorescence staining showed that in the silicosis model group, the expression of p-PERK increased at the location of silicotic nodules, while in the silicotic model + physical exercise intervention group, the expression of p-PERK decreased. The immunohistochemical staining results showed that the expression of p21 and p-p38 increased in the lung tissues of the silicosis model group; the expression of p21 and p-p38 decreased in the lung tissues of the silicosis model + physical exercise intervention group. The results of Western blotting showed that compared with the control group, the expression levels of p-IRE-1α (0.11±0.03), p-PERK (0.95±0.40), p-eIF-2α (3.53±0.91), p-p53 (1.78±0.07), p21 (1.98±0.10), p16 (1.26±0.17), p-p38 (0.41±0.09), p-ERK (0.42±0.05), and p-JNK (3.20±1.23) of the silicosis model group were all upregulated (P<0.05). Compared with the silicosis model group, the expression levels of p-IRE-1α (0.03±0.01), p-PERK (0.31±0.12), p-eIF-2α (0.30±0.06), p-p53 (0.76±0.08), p21 (0.18±0.11), p16 (0.70±0.24), p-p38 (0.03±0.00), p-ERK (0.19±0.03), and p-JNK (0.46±0.21) of the silicosis model + physical exercise intervention group were downregulated (P<0.05). Conclusion Physical exercise may alleviate pulmonary fibrosis in silicotic mice, and inhibit abnormal expressions of endoplasmic reticulum stress signal, MAPK signal, and senescent signal.

Establishment of mouse silicosis fibrosis model by non-exposed tracheal perfusion / 中国职业医学

Objective: To establish a convenient non-invasive tracheal perfusion method for constructing a mouse model of silicosis-induced pulmonary fibrosis. Methods: The specific pathogen-free C57BL/6 mice were randomly divided into control group and model group, with 15 mice in each group. After anesthesia, a 22G arteriovenous indwelling needle was used to inset into the trachea through the mice's mouth. The model group mice were perfused with 0.1 mL of silica suspension with a mass concentration of 25 g/L, and the mice in the control group were perfused with an equal volume of 0.9% sodium chloride solution. On the 7th, 14th, and 30th day after modeling, the body weight of the mice was measured, and the lung tissue morphology and pathological changes were observed. The expression of α-smooth muscle actin (α-SMA) and collagen type 1 alpha 1 (COL1A1) protein in lung tissue of mice was detected by immunofluorescence on the 30th day after modeling. Results: There was no death of mice in the two groups during the experiment. There was no significant difference in body weight between the two groups (P>0.05). The lung tissues of the mice in the model group were pinkish-gray and uneven in color on the 7th and 14th days after dust exposure. On the 30th day after dust exposure, the lung tissue of the mice in the model group was gray and hard, and unevenly distributed silicon nodules were visible by the naked eyes. The histopathology results of lung tissue showed that compared with the mice in control group, the model group mice exhibited persistent aggravation of pulmonary inflammation, thickening of alveolar septum, infiltration of inflammatory cells gradually clustering into clumps, and an increasing number of fibrous foci.On the 30th day after dust exposure, the relative expression of α-SMA and COL1A1 proteins in the lung of the model group was higher than those in the control group (median： 72.59 vs 5.91, 35.62 vs 10.07, both P<0.05). Conclusion: The method of tracheal perfusion silica suspension of mice using 22G arteriovenous indwelling needle can successfully construct an animal model of silicosis fibrosis. This method is convenient, safe and effective, and is worth promoting.

The role of surfactant associated protein-A in silicosis / 中国职业医学

Objective: To investigate the role of surfactant associated protein-A (SP-A) in the development and progression of silicosis, and its mechanism. Methods: Homozygous and heterozygous mice of SP-A knockout of specific pathogen free (SPF) grade were selected for mating, and mice with SP-A-/- genotype were selected for subsequent experiments. SP-A wild-type (SP-A+/+) and SP-A-/- mice were divided into SP-A+/+ control group, SP-A-/- control group, SP-A+/+ silicosis group and SP-A-/- silicosis group with six mice in each group by random number table method. Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure, and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume. On the 28th day after modeling, mice were sacrificed. Lung tissues were used for lung histopathology examination. The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method. The mRNA expression of B-lymphoblastoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction. Results: The histopathological result of mice showed that thickened alveolar septum, scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A+/+ silicosis group, and a large number of inflammatory cells were observed in silicosis nodule, after exposure to silica dust. SP-A-/- silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A+/+ silicosis group. The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax, Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups (all P<0.05). The above four indexes of mice in SP-A-/- silicosis group were higher than those in SP-A+/+ silicosis group (all P<0.05). There was no significant difference in the expression of Bcl-2 mRNA in lung tissues of these four groups (P>0.05). Conclusion: Knockout of SP-A can aggravate inflammation and pulmonary fibrosis in silicosis model mice, and promote apoptosis of alveolar type Ⅱ epithelial cells. The mechanism may be related to the Bcl-2/Bax/Caspase-3 signaling pathway which affects the apoptosis of mitochondrial pathway.