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.

Application of urinary proteomics in early diagnosis of bladder urothelial carcinoma / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the difference in urinary proteome between patients with bladder urothelial carcinoma (BUC) and healthy volunteers and to provide a basis for the early diagnosis of BUC.</p><p><b>METHODS</b>The urine samples from BUC patients and healthy volunteers (controls) were treated by 25% ethanol precipitation and two-dimensional gel electrophoresis (2-DE), and the obtained urinary proteins were subjected to Coomassie brilliant blue staining and analysis by PDQuest 8.0 (2-DE image analysis software); the differentially expressed proteins were sequenced by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry and identified using the Swiss-Prot database; the differential expression of these proteins was verified by western blot.</p><p><b>RESULTS</b>High-resolution and high-reproducibility 2-DE images were obtained from the urine samples of BUC patients and controls, with 789 ± 18 and 762 ± 14 protein spots, respectively. Compared with the control group, the BUC grouP had significantly decreased expression of 6 protein spots and significantly increased expression of 11 protein spots. The mass spectrometry revealed five proteins with increased expression in the BUC group, including fibrinogen, lactate dehydrogenase B, apolipoprotein A1, clusterin, and haptoglobin, and the results were confirmed by western blot.</p><p><b>CONCLUSION</b>There is significant difference in urinary proteome between BUC patients and healthy volunteers; the identification of differentially expressed proteins in urine lays the foundation for identifying potential molecular markers in early diagnosis of BUC.</p>

A case-control study on serum organochlorines residues, genetic polymorphisms of glutathione S-transferase T1 and the risks of breast cancer / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the potential effect of gene-environment interaction between glutathione S-transferase T1 (GSTT1) and serum organochlorines residues on the risk of breast cancer in women, in China.</p><p><b>METHODS</b>70 newly diagnosed female breast cancer patients and 30 controls from September 2006 to October 2007 were interviewed using the same questionnaire to obtain information regarding exposure to those risks. Organochlorine residues level in serum was measured by gas chromatography (GC). Genotypes of GSTT1 polymorphisms were analyzed by multiplex allele-specific polymerase chain reaction (PCR). Interaction indexes (gamma) were calculated to determine the type of gene-environment interaction.</p><p><b>RESULTS</b>After adjusting the confounding factors, results showed that interaction existed in genetic polymorphisms of GSTT1 and dichlorodiphenyltrichloroethane (DDT)/hexachlorocyclohexane (HCH) residues, with interaction indexes (gamma) value as 1.352 and 1.528.</p><p><b>CONCLUSION</b>Genetic and environmental hazard factors had a co-effect on the development of breast cancer while genetic polymorphisms of GSTT1 and DDT/HCH expressed an interaction to breast cancer.</p>

Early genetic effects on workers occupationally exposed to formaldehyde / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the DNA and chromosome damage in peripheral blood lymphocyte of workers occupationally exposed to formaldehyde (FA).</p><p><b>METHODS</b>All 151 workers occupationally exposed to FA from two plywood factories and 112 workers without occupational FA exposure working in a machine manufactory were recruited into this study. Comet assay and cytokinesis-block micronucleus technique was used to evaluate the DNA and chromosomal damage of peripheral blood lymphocyte. The air FA samples were collected with SKC 224-PCXR8 air samplers. Gas chromatography was used to analyze the FA level. Personal information including occupational history, age, sex, smoking and drinking status was collected by the questionnaire.</p><p><b>RESULTS</b>The time weighted average concentration (TWA) of FA in the working environment of FA-exposed workers (range 0.10 - 7.88 mg/m(3)) was higher than those in controls (< 0.01 mg/m(3)). The olive tail moment (Olive TM) in low FA-exposed workers [3.03 (2.49 - 3.67)] was lower than that in high FA-exposed workers [3.95 (3.53 - 4.43)], but higher than that in controls [0.93 (0.78 - 1.10)], the differences were statistical significant (P < 0.05). Comet trail length in FA-exposed workers were significantly higher than that in controls [6.78 (6.05 - 7.60)], but no significant differences ware found between the high FA-exposed workers [12.59 (11.80 - 13.43)] and the low FA-exposed workers [11.25 (10.12 - 12.50)]. The frequency of micronuclei per 100 binucleated cells in low FA-exposed workers (0.41 +/- 0.25) was lower than that in high FA-exposed workers (0.65 +/- 0.36), but higher than that in controls (0.27 +/- 0.13), the differences were statistical significant (P < 0.05). The increased tendencies with the exposure levels were found in those three indices. In stratification analysis, the same results were found.</p><p><b>CONCLUSION</b>In the current FA exposure levels, the DNA and chromosomal damage in peripheral blood lymphocyte might be induced by FA exposure, and be increased with the levels of exposure.</p>