Application of a light-weighted convolutional neural network for automatic recognition of coal workers' pneumoconiosis in the early stage / 中华劳动卫生职业病杂志

Objective: To construct and verify a light-weighted convolutional neural network (CNN), and explore its application value for screening the early stage (subcategory 0/1 and stage Ⅰ of pneumoconiosis) of coal workers' pneumoconiosis (CWP) from digital chest radiography (DR) . Methods: A total of 1225 DR images of coal workers who were examined at an Occupational Disease Prevention and Control Institute in Anhui Province from October 2018 to March 2021 were retrospectively collected. All DR images were collectively diagnosed by 3 radiologists with diagnostic qualifications and gave diagnostic results. There were 692 DR images with small opacity profusion 0/- or 0/0 and 533 DR images with small opacity profusion 0/1 to stage Ⅲ of pneumoconiosis. The original chest radiographs were preprocessed differently to generate four datasets, namely 16-bit grayscale original image set (Origin16), 8-bit grayscale original image set (Origin 8), 16-bit grayscale histogram equalized image set (HE16) and 8-bit grayscale histogram equalized image set (HE8). The light-weighted CNN, ShuffleNet, was applied to train the generated prediction model on the four datasets separately. The performance of the four models for pneumoconiosis prediction was evaluated on a test set containing 130 DR images using measures such as the receiver operating characteristic (ROC) curve, accuracy, sensitivity, specificity, and Youden index. The Kappa consistency test was used to compare the agreement between the model predictions and the physician diagnosed pneumoconiosis results. Results: Origin16 model achieved the highest ROC area under the curve (AUC=0.958), accuracy (92.3%), specificity (92.9%), and Youden index (0.8452) for predicting pneumoconiosis, with a sensitivity of 91.7%. And the highest consistency between identification and physician diagnosis was observed for Origin16 model (Kappa value was 0.845, 95%CI: 0.753-0.937, P<0.001). HE16 model had the highest sensitivity (98.3%) . Conclusion: The light-weighted CNN ShuffleNet model can efficiently identify the early stages of CWP, and its application in the early screening of CWP can effectively improve physicians' work efficiency.

Effects of heat exposure and vitamin C intervention on oxidative stress and blood pressure changes in treadmill rats / 中华劳动卫生职业病杂志

Objective: To investigate the effect of oxidative stress caused by heat exposure on the blood pressure increase of treadmill rats and the intervention of antioxidants. Methods: In June 2021, Twenty-four healthy SD male rats were randomly divided into four groups: normal temperature feeding, normal temperature treadmill, high temperature treadmill and high temperature treadmill supplementation with vitamin C groups, 6 rats in each group. The rats run on the platform in normal temperature or heat exposure environment for 30 min in the morning and in the afternoon daily, 6 days per week. The daily vitamin C supplement dose of high temperature treadmill supplementation with vitamin C group was 10 mg/kg. BP recordings were done at the end of the week. The rat vascular lipofuscin (LF) was detected by ELISA, the rat serum nitric oxide (NO) was detected by nitrate reductase method, the serum malondialdehyde (MDA) was detected by thibabituric acid method, the serum glutathione peroxidase (GPx) and superoxide dismutase (SOD) were detected by chemiluminescence method, and the serum catalase (CAT) was detected by ammonium molybdate method. The total antioxidant capacity (T-AOC) of serum was measured by iron reduction/antioxidant capacity method, and the content of nuclear erythroid 2-related factor 2 (Nrf2) in vascular tissue was measured by Western blot. The intra-group mean was compared by repeated measurement analysis of variance, and the inter-group mean was compared by single-factor analysis of variance and post-event LSD-t test. Results: Compared with the previous time point, the systolic BP and diastolic BP of the high temperature treadmill group were significantly increased at 7, 14 and 21 d, and decreased at 28 d which were higher than the initial level (P<0.05), and the systolic BP and diastolic BP values at each experimental time point were significantly higher than those of normal temperature treadmill group (P<0.001). The changes of thickening of the artery wall, no smoothing of the endodermis and irregular arrangement of muscle cells in high temperature treadmill group were observed. Compared with the normal temperature treadmill group, the content of MDA in serum, and LF in vascular tissue were significantly increased, the activities of SOD, CAT, T-AOC, the content of NO in serum, and the expression of Nrf2 in vascular tissue were significantly decreased in high temperature treadmill group (P<0.05). Compared with the high temperature treadmill group, the systolic BP and diastolic BP values at 7, 14, 21 and 28 d, the content of serum MDA and LF in vascular tissue were significantly decreased, the activities of CAT and T-AOC, and the expression of Nrf2 in vascular tissue significantly increased (P<0.05), the histopathological changes of the artery wall improved in high temperature treadmill supplementation with vitamin C group. Conclusion: Heat exposure has effect on oxidative stress, which may be related to the increase of BP. Vitamin C as an anti-oxidative enhancer can prevent those negative effects, which could alleviate the pathological changes of vessel intima in heat-exposed rats. And the Nrf2 may be a regulated factor to vascular protection.

Correlation between intestinal and respiratory flora and their metabolites in a rat pneumoconiosis model / 中华劳动卫生职业病杂志

Objective: Differential flora and differential metabolites shared by the intestinal and respiratory tracts of rats were screened to analyze the possible role of changes in intestinal flora and metabolites in the progression of pneumoconiosis in rats. Methods: In April 2020, 18 SD rats were randomly divided into three groups (control group, coal mine dust group and silica group, 6 in each group) , rats in the coal mine dust group and silica group were perfused with 1 ml of 50 mg/ml coal mine well dust suspension and silica suspension by nontracheal exposure, respectively. While rats in the control group were perfused with an equal dose of sterilized normal saline. Twenty four weeks after dust staining, rat feces, throat swabs, and lung lavages were collected. 16SrDNA gene sequencing and UHPLC-QTOF-MS untargeted metabolomics were used to analyze the flora and metabolites in feces, throat swabs and lung lavage fluid of rats in each group, to screen for shared differential flora and shared differential metabolites in intestinal and respiratory tract, and the correlation analysis between the differential flora and metabolites was performed using Spearman's statistics. Results: Compared with the control group, a total of 9 species shared differential flora between intestinal and respiratory tract were screened at phylum level, and a total of 9 species shared differential genus between intestinal and respiratory tract were screened at genus level in the coal mine dust group, mainly Firmicutes, Actinobacteria, Streptococcus, Lactobacillus, etc. Compared with the control group, a total of 9 shared differential flora were screened at the phylum level, and a total of 5 shared differential genus were screened at the genus level in the silica group, mainly Proteobacteria, Actinobacteria, Allobactera, Mucilaginibacter, etc. Compared with the control group, a total of 7 shared differential metabolites were screened for up-regulation of Stigmatellin, Linalool oxide and Isoleucine-leucine in both intestinal and respiratory tract in the coal mine dust group. Compared with the control group , a total of 19 shared differential metabolites werescreened in the silica group, of which Diethanolamine, 1-Aminocyclopropanecarboxylic acid, Isoleucine-leucine, Sphingosine, Palmitic acid, D-sphinganine, 1, 2-dioleoyl-sn-glycero-3-phosphatidylcholine, and 1-Stearoyl-2-oleoyl-sn-glycerol 3-phosphocholine were up-regulated in both the intestinal and respiratory tract. Conclusion: There is a translocation of intestinal and respiratory flora in pneumoconiosis rats, and rats have an imbalance of lipid metabolism during the progression of pneumoconiosis.

Prediction of occupational coal workers′ pneumoconiosis incidence by a multi-layer perceptron neural network model / 中国职业医学

OBJECTIVE: To construct and verify the incidence prediction model of occupational coal workers′ pneumoconiosis(CWP) in coal mine workers exposed to dust(hereinafter referred to as ″dust exposure″) based on a multi-layer perceptron(MLP) neural network, and explore its application value in predicting CWP incidence. METHODS: A total of 17 023 dust exposed workers in a coal mining group in Hebei Province from 1970 to 2017 were selected as the research subjects by a typical sampling method. Among them, 839 patients were confirmed as CWP and 16 185 workers did not suffered from CWP. The MLP neural network model was established with the incidence of CWP as the target output variable, and the type of work, age, beginning year of dust exposure, observation year(i.e. incubation period) and cumulative dust exposure as the input variable. The receiver operating characteristic(ROC) curve was used to evaluate the predictive ability of the built model. The established model was used to predict the high-risk group and key monitoring group population of CWP in dust-exposed workers in the following 10 years. RESULTS: There were 44 synapses in the hidden layer of the established MLP neural network model. The area under ROC curve was 0.91. The accuracy, sensitivity and specificity of the model were 92.7%, 74.8% and 93.6%, respectively. In the validation samples, the accuracy, sensitivity and specificity were 92.1%, 70.5% and 93.2%, respectively. The MLP neural network model was used to predict 1 534 workers with high risk of CWP in the following 10 years, and the individuals were located. The number of workers in need of actively monitored was 7 599. Among them, it is predicted that the incidence of CWP in different types of dust exposed workers in the following 10 years from high to low is tunneling worker, coal miner, mixing worker and auxiliary worker(P<0.01). The earlier the dust exposure began, the higher the risk of CWP(P<0.01). CONCLUSION: The MLP neural network model based on the type of work, age, beginning year of dust exposure, incubation period and cumulative dust exposure has a good performance in predicting the incidence of CWP in coal mine dust exposure workers, and can provide a reference for early preventive management measures to prevent and cure CWP.

Analysis on protein expression of ferritin light chain in alveolar macrophages of patients with occupational silicosis / 中国职业医学

OBJECTIVE: To observe the protein expression of ferritin light chain(FTL) in alveolar macrophages(AM) of patients with occupational silicosis(hereinafter referred to as silicosis). METHODS: The male patients with silicosis at stage Ⅰ, Ⅱ, and Ⅲ were separately selected as the silicosis groupⅠ, Ⅱ, and Ⅲ using judgment sampling method, with 15 patients in each group. Meanwhile, 15 male silicon dust workers with small lung shadows but not diagnosed as silicosis were selected as the control group. Bronchoalveolar lavage fluid was collected from the four groups, and AM was separated and purified, and protein was extracted after lysis of the AM. Western blotting was used to detect the relative expression of FTL protein in the AM. RESULTS: The relative expression of FTL protein in AM of silicosis groupⅠ, Ⅱ, and Ⅲ was lower than that in the control group(all P<0.05). The relative expression of FTL protein in AM decreased with the increase of silicosis stage(P<0.05).CONCLUSION: The expression of FTL protein in AM was down-regulated in patients with silicosis in a dose-response manner. It is speculated that FTL may have a negative regulatory effect in the progress of silicosis fibrosis.

Effects of PI3K / Akt signaling pathway on the autophagy of rat alveolar macrophages exposed to dust / 中国职业医学

OBJECTIVE: To determine the regulating role of phosphatidylinositol 3-kinase( PI3K) / protein kinase B( Akt)signaling pathway in the autophagy activity of rat NR8383 cells exposed to silicon dioxide( SiO_2). LY294002 was used to block PI3 K pathway. METHODS: i) The normal NR8383 cells were used and divided into blank group and silica exposure group( final concentrations of SiO_2 suspension were 0 and 50 mg / L respectively). They were cultured for 3,6,12,20 and24 hours. The enzyme linked immunosorbent assay( ELISA) was used to assess the amount of tumor necrosis factor-α( TNF-α) and transforming growth factor-β1( TGF-β1) in supernatants of cultured cells,and then the optimal time of cells exposed to dust was determined. ii) NR8383 cells were divided into control group( treated with a same volume of F-12 K medium without serum),silica group( treated with SiO_2 suspension,final concentration 50 mg / L) and intervention group( treated with SiO_2 suspension and PI3 K inhibitor LY294002,final concentration 50 mg / L and 20 μmol / L,respectively).Cells were harvested following incubation. ELISA was used to detect the levels of TNF-α and TGF-β1 at the time point of20 hours after incubation. To reveal the autophagy status of cells,Western blotting was used to detect Akt and microtubuleassociated proteins 1 light chain 3( LC3) protein at time point of 20 hours; laser scanning confocal microscope( LSCM)was used to observe the immunofluorescence expression of autophagy at time points of 3,6,12 and 20 hours. The cells were also treated with the lysosomal inhibitor chloroquine diphosphate( CDP) at the same time of SiO_2 treatment. RESULTS: i) The time point of 20 hours was confirmed to be the best dust exposure time for in vitro cell model of NR8383 cells.ii) The levels of TNF-α and TGF-β1 of supernatant in the silica group were higher than those of the control group( P <0. 05). The levels of TNF-α and TGF-β1 of supernatant in the intervention group were higher than those of the control group and silica group( P < 0. 05). The Akt protein expression of the intervention group was lower than those in the control group and the silica group,respectively. The LC3 Ⅱ / Ⅰ protein level of the silica group was higher than those of the control group and intervention group( P < 0. 05),but no statistical significance was found between the control group and intervention group( P > 0. 05). LSCM results indicated that autophagy expression at time points of 3 and 6 hours were stronger than those of 12 and 20 hours in control group; autophagy expression at time point of 12 hours was stronger than those of 3 and 6 hours in the silica group,while the autophagy expression at time point of 20 hours was slightly weaker than that of 12 hours,but still stronger than those of 3 and 6 hours. Compared with the same time point in control group,autophagy expression at 3 and 6 hours were weaker in the silica group,while the expressions increased obviously at time points of 12 and 20 hours. Autophagy expression at all time points decreased in the intervention group compared with silica group,especially at the time point of 20 hours. The autophagy expression in each group increased in varying degrees after added with CDP blocking. CONCLUSION: Silica dust exposure can induce autophagy in rat NR8383 cells. PI3 K inhibitor LY294002 can reduce the autophagy expression indicating that the PI3 K / Akt signaling pathway might participate in the autophagy process of silica dust inducing autophagy in alveolar macrophages.

Case-control study of relationship between polymorphisms of interleukin-4 gene and susceptibility of silicosis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between polymorphisms of interleukin-4 (IL-4) gene (-33, +45, VNTR, +429, +448) and the susceptibility of silicosis.</p><p><b>METHODS</b>In a case-control study, the case group consisted of 101 patients with silicosis, and was matched with the control group (121 workers without silicosis), according to the age, sex, nationality, working place, exposure to dust. The polymorphisms of IL-4 (five locus) detected by the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques.</p><p><b>RESULTS</b>There was no difference of age, exposure and smoking between case group and control group (P > 0.05). The two groups had good comparability. Only the GA genotype in the IL-4 (+429) locus was found, the genotypes of AA and GG were not found. The CC genotype in the IL-4 (+448) locus was found, the genotypes of CG and GG were not found. The frequencies of AA, GG and AG of IL-4 (+45) locus in the case and control groups were 55.4%, 10.9%, 33.7% and 62.0%, 11.6%, 26.4%, respectively, there was no the significant difference between case and control groups (P > 0.05). The frequencies of B1B1, B2B2 and B1B2 of IL-4 (VNTR) locus in the case and control groups were 73.3%, 1.0%, 25.7% and 68.6%, 1.7%, 29.8%, respectively, there was no the significant difference between case and control groups (P > 0.05). The frequencies of TT, CC and CT in IL-4 -33 locus in the case group were 55.4%, 11.9% and 32.7%, which were significantly higher than those (69.4%, 4.1%, 26.4%) in control group (P < 0.05).</p><p><b>CONCLUSIONS</b>There was no relationship between IL-4 (+45, VNTR) genotypes and prevalence of silicosis in this study. The polymorphisms of IL-4 (+448) site were not found which may be related to the race. The relationship between genetic polymorphism of IL-4 (-33) locus and silicosis development was found, Workers with IL-4 (-33) allele C are susceptible to the silica.</p>

Investigation about prevention behavior for dust workers in machinery, ceramic, and metallurgy industry / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>The purposes of this thesis were to study the behavior about workers exposed to dust and provide scientific basis for health promotion.</p><p><b>METHODS</b>We designed a questionnaire and carry it on the 746 dust workers in the 3 representative corporations of Machinery, Ceramic, and Metallurgy Industry. All data were input into computer. And a database was established with Excel. SPSS11.5 statistical analysis software was used to analyze the influence on protecting behavioral between the application of qualifications, different jobs, training or protection, and other aspects etc.</p><p><b>RESULTS</b>The rates were 94.4% and 75.3% about the regular physical examination and requirements for protective equipment. The rate of choosing an effective way of protection was generally low (15.4%). There was significant difference for among different educational background workers (P < 0.01). The rates of choosing an effective way of protection (20.3%), the regular physical examination (98.3%) and requirements for protective equipment (86.4%) in the dust workers who participated in the training of dust protection were superior than those who did not participated in the training. There was the significant difference (P < 0.05, P < 0.01). There was the significant difference for the rate of effective way of protection, regular physical examination, and requirements for protective equipment among the different corporations (P < 0.05).</p><p><b>CONCLUSIONS</b>Dust workers' using rate about the choosing an effective way of protection was generally low in Machinery, Ceramic, and Metallurgy Industry. Those who were not educated had a lower using rate about the protection behavior, regular physical examination, and requirements for protective equipment than those educated.</p>

The relationship between polymorphisms of interleukin-4 gene and silicosis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the relationship between polymorphisms of interleukin-4 (IL-4) gene (-33, +45, intron3, +429, +448) and the susceptibility of silicosis.</p><p><b>METHODS</b>A case-control study was carried out. 101 silicosis patients were selected as cases. As strictly matching, 121 of non silicosis workers were selected as the controls. The polymophisms of IL-4 (five locus) were detected by the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques.</p><p><b>RESULTS</b>The GA genotype in the IL-4+429 locus and the CC genotype in the IL-4+448 locus were found. The frequencies of AA, GG and AG of IL-4+45 locus in the cases were 55.4%, 10.9%, and 33.7% and in the controls were 62.0%, 11.6%, and 26.4%. The differences between cases and controls were not significant. The frequencies of B1B1, B2B2, and B1B2 of intron3 VNTR locus in the cases were 73.3%, 1.0%, and 25.7% and in the controls were 68.6%, 1.7%, and 29.8%. The differences were not significant. The frequencies of TT, CC, and CT in -33 locus in the cases were 55.4%, 11.9%, and 32.7% and in the controls were 69.4%, 4.1%, and 26.4%. The differences were significant (P=0.034).</p><p><b>CONCLUSION</b>The relationship between genetic polymorphism of IL-4-33 site and silicosis has been found and -33TT is a protective genotype for silicosis.</p>

Decrease of cyclin D1 and CDK4 protein and their related factors induced by quartz in human embryonic lung fibroblasts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the expression level of cyclin D1-CDK4 protein in human embryonic lung fibroblasts (HELF) induced by quartz, and to study whether the expression level of cyclin D1-CDK4 protein mediated by mitogen activated protein kinase (MAPK)/(AP-1) signaling pathways.</p><p><b>METHODS</b>Cells were harvested after stimulation 2 h for the detection of cytokines. Cyclin D1 and CDK4 (cyclin dependent kinase 4) proteins was measured by immunocytochemistry (IC) and Western blot (WB).</p><p><b>RESULTS</b>The exposure of HELF to crystalline quartz for 2 hours could cause the decrease of cyclin D1 and cyclin dependent kinase 4 (CDK4) protein expression level, (7.91 +/- 0.29) x 10(3) and (5.17 +/- 0.28) x 10(4) respectively, which was lower than that of the HELF group (P < 0.05). AG126 (chemical inhibitor of the extracellular signal regulated protein kinase (ERK) signaling pathway) and the dominant negative mutant of ERK2 (molecular inhibitor of ERK2), prevented the decrease of cyclin D1 and CDK4 protein expression level. The chemical inhibitor of c-Jun NH2-terminal amino kinase (JNK), SP600125, could prevent both cyclin D1 and CDK4 protein expression level decrease. But SB203580, the chemical inhibitor of p38, prevented neither cyclin D1 nor CDK4 protein expression level decrease. Curcumin could prevent CDK4 protein expression level decrease but not cyclin D1 protein.</p><p><b>CONCLUSION</b>ERKs and JNKs, but not p38, are responsible for the decrease of cyclin D1 and CDK4 protein expression level in HELF induced by quartz. AP-1 is responsible for the decrease of CDK4 expression level but not that of cyclin D1.</p>

Investigation on job stress of pediatricians and nurses working in pediatric department / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the occupational stressors and modifiers of pediatricians and nurses in order to find the measurements for control of the job stress.</p><p><b>METHODS</b>427 pediatricians and nurses working in five hospitals of a city served as subjects. Of them, the staff in section of pharmacy and toll offices in each hospital mentioned above served as control group. The General Job Stress Questionnaire was used to investigate the job stress by self-assessment.</p><p><b>RESULTS</b>The scores of job demand, job risk, drug using, daily job stress, positive feelings, patient A behavior, physical environment and feeling balance in pediatricians and nurses were higher than those of control group, but the scores of job-person conflict, environmental control, technology utility, mental health, responsibility on things were lower than those of control group (P<0.05). The points of job future, job locus of control, self-esteem, job satisfaction, job load variance, depression in nurses were higher than those of pediatricians, and non-work activities, job risk and daily life stress were lower than those of doctors (P<0.05). The main affecting factors on job strain of pediatric staff included job monotony, higher job demand, more non-work job, lower job control, more job risk, job future ambiguous, poorer social support, lower job locus control and lower self-esteem.</p><p><b>CONCLUSION</b>The stress degree of pediatric staff is higher than that of controls. The pediatricians have more job stress than that of nurses. The main stressors of pediatric staff are job monotony, higher job demand, more non-worker activity, lower job control, higher job risk and ambiguous job future. The main modifiers are good social support, external job locus of control and higher self-esteem.</p>

Different patterns of cyclin D1/CDK4-E2F-1/4 pathways in human embryo lung fibroblasts treated by benzoapyrene at different doses / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the roles of the cyclin D1/CDK4 and E2F-1/4 pathways and compare their work patterns in cell cycle changes induced by different doses of B[a]P.</p><p><b>METHODS</b>Human embryo lung fibroblasts (HELFs) were treated with 2 micromol/L or 100 micromol/L B[a]P which were provided with some characteristics of transformed cells (T-HELFs). Cyclin D1, CDK4 and E2F-1/4 expressions were determined by Western blotting. Flow cytometry was used to detect the distribution of cell cycle.</p><p><b>RESULTS</b>After B[a]P treatment, the proportion of the first gap (G1) phase cells decreased. CDK4 and E2F-4 expression did not change significantly. In 2 micromol/L treated cells, a marked overexpression of cyclin D1 and E2F-1 was observed. However, in T-HELFs overexpression was limited to cyclin D1 only, and no overexpression of E2F-1 was observed. The decreases of G1 phase in response to B[a]P treatment were blocked in antisense cyclin D1 and antisense CDK4 transfected HELFs (A-D1 and A-K4) and T-HELFs (T-A-D1 and T-A-K4). After 2 micromol/L B[a]P treatment, overexpression of E2F-1 was attenuated in A-D1, and E2F-4 expression was decreased significantly in A-K4. In T-A-D1 and T-A-K4, E2F-4 expression was increased significantly, compared with T-HELFs. The E2F-1 expression remained unchanged in T-A-D1 and T-A-K4.</p><p><b>CONCLUSIONS</b>Cyclin D1/CDK4-E2F-1/4 pathways work in different patterns in response to low dose and high dose B[a]P treatment. In HELFs treated with 2 micromol/L B[a]P, cyclin D1 positively regulates the E2F-1 expression while CDK4 negatively regulates the E2F-4 expression; however, in HELFs treated with 100 micromol/L B[a]P, both cyclin D1 and CDK4 negatively regulate the E2F-4 expression.</p>

Benzo (a) pyrene-induced human embryo lung cell cycle alterations through positive regulation of mitogen-activated protein kinase signal pathways / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects of benzo(a)pyrene (BaP) on the cell cycle distribution and activities of mitogen-activated protein kinase (MAPK) signal molecules (ERK1/2, JNK1/2 and p38) in human embryo lung cells (HELF), and to investigate the relationship between alterations of MAPK protein phosphorylation and the cell cycle distributions.</p><p><b>METHODS</b>The phosphorylation of MAPK were induced by exposing HELF cells to BaP at 0.1, 0.5, 2.5 and 12.5 micromol/L. The phosphorylation and protein expression levels of ERK1/2, JNK1/2 and p38 were determined through western-blotting assay. And the flow cytometry assay was used to measure the cell cycle effects in HELF cells after treatment with 2.5 micromol/L BaP for 24 h.</p><p><b>RESULTS</b>The phosphorylation levels of ERK1/2, JNK1/2 and p38 were significantly increased through BaP exposure. In addition, the phosphorylation of these three MAPKs has similar alteration pattern. We found that exposure of cells to 2.5 microM of BaP for 24 h resulted in a decrease of G(0) and G(1) population by 11.9% (F = 41.38, P < 0.01) and an increase of S population by 17.2% (F = 68.13, P < 0.01). Three chemical inhibitors of MAPK (AG126, SP600125 and SB203580) could significantly inhibit the cell cycle alteration because of BaP treatment.</p><p><b>CONCLUSION</b>ERK1/2, JNK1/2 and p38 could positively regulate the BaP independently induced cell cycle alterations.</p>

The activation of MAPK/cyclin D1-CDK4 signaling pathway caused by quartz / 中华劳动卫生职业病杂志

<p><b>OBJECTIVES</b>To study the phosphorylation level of mitogen activated protein kinase (MAPK) in human embryonic lung fibroblasts (HELF), and the expression level of cyclin D1-CDK4 protein in S-HELF and whether the expression level of cyclin D1-CDK4 protein mediated by MAPK/AP-1 signaling pathway in S-HELF.</p><p><b>METHODS</b>Two kinds of treatment: (1) Cells were harvested after stimulation 2 h for the detection of cytokines. (2) Cells were stimulated by quartz for a long time (2 months) for transformation characters (S-HELF). The MAP kinase was detected by western blot. Cyclin D1 and CDK4 (cyclin dependent kinase 4) proteins was measured by immunocytochemistry. Flow cytometry was used to evaluate the alternation of cell cycle.</p><p><b>RESULTS</b>Crystalline quartz could cause the phosphorylation level of ERKs, p38K, and JNKs in HELF increase. However, activated levels of ERKs and p46 of JNKs increased in S-HELF, and p38K activation decreased, and no effect on activation of p54 of JNKs, as compared with those in parental HELF. Cyclin D1 and CDK4 protein expression levels increased in S-HELF as compared with parental HELF. Inhibition of ERKs activation by AG126, AP-1 by curcumin, and JNKs by SP600125 could reduced the induction of cyclin D1 and CDK4, whereas inhibition of p38K by SB203580 did not show any inhibitory effects on S-HELF.</p><p><b>CONCLUSIONS</b>The phosphorylation levels of ERK1/2, JNK1/2, and p38 increased in HELF exposed to quartz. The phosphorylation levels of ERK1/2 and JNK1 increased, but the phosphorylation level of p38 decreased in S-HELF. The expression level of cyclin D1-CDK4 protein increased in S-HELF. Overexpression of cyclin D1-CDK4 is due to the activation of ERKs, JNKs/AP-1 signaling pathway in S-HELF.</p>

cyclin D1/E2F pathways involved in cell cycle changes of human embryo lung fibroblasts induced by benzo(a)pyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the roles of cyclin D1/CDK4-E2F-1/4 pathway in cell cycle changes of human embryo lung fibroblasts (HELF) induced by two different benzo(a)pyrene [B(a)P] treatment models.</p><p><b>METHODS</b>Two B(a)P treatment models: HELF were treated by 2 micromol/L B(a)P for 24 hours; HELF were treated by 100 micromol/L B(a)P three times 24 hours each and provide with some characteristics of transformed cells (T-HELF). Changes of cell cycle and the expression of cyclin D1, CDK4 and E2F-1/4 were checked using the flow cytometry and Western bolt analysis.</p><p><b>RESULTS</b>After 24 hours 2 microml/L B(a)P treatment, the HELFs in the G(1) phase was decreased. In HELF transfected with antisense cyclin Dl (A-Dl) and antisense CDK4 (A-K4), the expression of cyclin Dl and CDK4 blocked the cell cycle changes from the G(1) phase to the S phase induced by B(a)P. The overexpression of cyclin Dl and E2F-1 in HELF was induced by B(a)P. The E2F-1 overexpression in A-D1 induced B(a)P was inhibited. The E2F-4 expression was decreased and the CDK4 expression was increased significantly in A-K4 after B(a)P treatment. Most of T-HELF transfected with antisense cyclin Dl (T-A-Dl) and antisense CDK4 (T-A-K4) were retained in G(1) phase. The cyclin Dl expression in T-HELF was increased significantly compared with that in HELF. The E2F-4 expression in T-A-Dl and T-A-K4 was increased significantly compared with that in T-HELF.</p><p><b>CONCLUSION</b>B(a)P induces the cell cycle changes through cyclin D1/CDK4-E2F-1/4 pathway in HELF treated by 2 micromol/L B(a)P while it induces cell cycle changes through cyclin D1/CDK4-E2F-4 pathway in T-HELF.</p>

Vitamin C inhibits benzoapyrene-induced cell cycle changes partly via cyclin D1/E2F pathway in human embryo lung fibroblasts / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the molecular mechanism of the inhibitory effects of vitamin C on benzo[a]pyrene (B[a]P)-induced changes of cell cycle in human embryo lung fibroblast (HELF) cells.</p><p><b>METHODS</b>The stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established. Cells were cultured and pretreated with vitamin C before stimulation with B[a]P for 24 h. The expression levels of cyclin D1, CDK4, E2F1, and E2F4 were determined by Western blot. Flow cytometric analysis was employed to detect the distributions of cell cycle.</p><p><b>RESULTS</b>B[a]P significantly elevated the expression levels of cyclin D1, E2F1, and E2F4 in HELF cells. Vitamin C decreased the expression levels of cyclin D1, E2F1, and E2F4 in B[a]P-stimulated HELF cells. Dose-dependent relationships were not found between the different concentrations of vitamin C (10, 100, 500, 1000, and 5000 micromol/L) and the expression levels of cyclin D1, E2F1, and E2F4 in HELF cells. The expression levels of cyclin D1, E2F1, and E2F4 in B[a]P-treated transfectants were lower than those in B[a]P-treated HELF cells. The expression levels of cyclin D1 and E2F4 treated with vitamin C and antisense cyclin D1 were decreased compared with those treated with antisense cyclin D1 alone. The effects of vitamin C combined with antisense CDK4 on the expression levels of cyclin D1 and E2F1/E2F4 were similar to those of antisense CDK4 alone. B[a]P progressed HELF cells from G1 to S phase. Both vitamin C and antisense cyclin D1 suppressed the changes of cell cycle progressed by B[a]P. However, antisense CDK4 did not attenuate the above changes. Vitamin C combined with antisense CDK4 markedly suppressed B[a]P-induced changes of cell cycle as compared with antisense CDK4. But the inhibitory effects of vitamin C combined with antisense cyclin D1 on B[a]P-induced changes of cell cycle were similar to those of vitamin C alone or antisense cyclin D1 alone.</p><p><b>CONCLUSIONS</b>B[a]P progressed HELF cells from G1 to S phase via intracellular signaling pathway of cyclin D1/E2F. Vitamin C may modulate this signaling pathway to protect cells from injury caused by B[a]P.</p>

Vitamin C reverses benzo (a) pyrene-induced cell cycle changes by E2F pathway / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the role of E2F1/4 pathway in vitamin C reversing benzo (a) pyrene [B (a) P]-induced changes of cell cycle in human embryo lung fibroblasts (HELF) and the relationship between E2F1 and cyclin D1/CDK4.</p><p><b>METHODS</b>The stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established to detect the relationship of signaling pathway. Cells were cultured and pretreated with vitamin C before stimulation with B (a) P for 24 hours. The expression levels of cyclin D1, CDK4, E2F1 and E2F4 were determined by Western blot and the band intensity was analysed as the relative value to control by using the Gel-Pro 3.0 software. Flow Cytometric Analysis was employed to detect the distributions of cell cycle.</p><p><b>RESULTS</b>B (a) P significantly elevated the expression levels of cyclin D1, CDK4, E2F1 and E2F4 in HELF cells. Vitamin C decreased the expression levels of above proteins in B (a) P-stimulated HELF cells. The expression levels of these proteins in B (a) P-treated above transfectants were lower than those in B (a) P-treated HELF cells. The expression levels of above proteins with vitamin C combined with antisense cyclin D1 were decreased as compared to those with antisense cyclin D1 alone. B (a) P increased the percentage of S phase as compared to the controls [(41.1 +/- 0.2)% vs (33.5 +/- 3.2)%, P < 0.05]. Both vitamin C [(33.2 +/- 0.6)% vs (41.1 +/- 0.2)%, P < 0.05] and antisense cyclin D1 [(31.2 +/- 1.3)% vs (41.1 +/- 0.2)%, P < 0.05] suppressed the changes of cell cycle induced by B (a) P. Vitamin C combined with antisense CDK4 markedly suppressed B (a) P-induced changes of cell cycle as compared to those with antisense CDK4 alone.</p><p><b>CONCLUSION</b>Vitamin C might reserve the B (a) P-induced changes of cell cycle via intracellular signaling pathway of cyclin D1-CDK4/E2F-1/4.</p>

Inhibition of the pathway of benzo (a) pyrene-induced cell cycle changes by all-trans retinoic acid in lung fibroblast / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the reverse effect of all-trans retinoic acid (ATRA) on Benzo (a) pyrene (B (a) P)-induced cyclin D1, CDK4, E2F-1 and E2F-4 expression and cell cycle progression in human embryo lung fibroblast (HELF).</p><p><b>METHODS</b>After HELF cells was treated with ATRA, they were exposed to 2 micromol/L of B (a) P. Western blotting was employed to detect protein expression level; the RNA transfection techniques was used to investigate ATRA-induced signal pathway; flow cytometry was used to detect cell cycle progression.</p><p><b>RESULT</b>After treatment with 2 micromol/L B (a) P for 24 h, the expression of cyclin D1 and E2F-1 were both increased significantly in HELF; the expression of E2F-4 and CDK4 were not changed markedly; pretreatment with 0.1 micromol/L ATRA for 24 h could efficiently decrease B (a) P-induced overexpression of cyclin D1 and E2F-1; stimulation to antisense cyclin D1 or antisense CDK4 by B (a) P could significantly impair E2F-1 up-regulation; pretreatment with ATRA, cells with antisense cyclin D1 or antisense CDK4 showed a less decrease in B (a) P-induced overexpression of E2F-1 compared to similarly treated control cells; flow cytometry analysis showed B (a) P promoted cell cycle progression from G(1) phase to S phase, while pretreatment with ATRA could inhibit B (a) P-induced cell cycle progression by an accumulation of cells in the G(1) phase.</p><p><b>CONCLUSION</b>ATRA could block B (a) P-induced cell cycle promotion through cyclin D1/E2F-1 pathway in HELF.</p>