OBJECTIVETo investigate the effect of CCM3 gene defection on lead induced cell genotoxicity in mouse embryonic fibroblasts.

METHODSC57 female mice were mated with CCM3 gene heterozygous male mice. E13.5 embryos were taken to isolate primary mouse embryonic fibroblasts. After genotyping, wild type and heterozygous cells were treated with different doses of lead acetate. Cell viability, genotoxicity and protein expression were detected by MTS assay, CB micronucleus method and Western blot, respectively.

RESULTSMouse embryonic fibroblasts with lead acetate treatment for 24 h, wild-type cells 100.00 µmol/L lead acetate-treated group (69.16±1.36) and the control group (100.00±2.33) compared to cells decreased by 30%, CCM3 heterozygous type cell 100.00 µmol/L lead acetate-treated group (87.16±5.50) and the control group (100.00±2.06) compared to cells decreased by 13%, the difference was statistically significant (F values were 98.59, 82.63, P<0.001). Lead acetate treatment after 48 h, wild-type cells 100.00 µmol/L lead acetate-treated group (51.99±5.62) and the control group (100.00±3.11) compared to cells decreased by 50%, heterozygous type cells 100.00 µmol/L lead acetate treatment group (66.33±4.06) and the control group (100.00±5.72) compared to cells decreased by 35%, the differences were statistically significant (F values were 82.63, 36.86, P < 0.001). The results of CBMN test showed that with increased dose, micronucleus cell rate of two genotypes showed an increasing trend, in the wild-type cells, the micronucleus cell rate (/1 000) for the control group, 29.6±2.2, 6.25 µmol/L dose group 47.3±6.6, 25 µmol/L dose group 55.5±9.1, 100.00 µmol/L dose group 66.8±3.5; heterozygous cells micronucleus cell rate (/1 000) for the control group, 35.3±5.6, 6.25 µmol/L dose of 50.0±8.3, 25.00 µmol/L dose group 57.0±8.5, 100.00 µmol/L dose group 58.8±2.1. Micronucleus cell rates (/1 000) were significant differences, in 100.00 µmol/L dose groups of two genotypes. Western blot results showed that wild-type cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.70±0.03) was 1.32 times higher than the control group (0.53±0.07), heterozygous cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.48±0.02) was 1.77 times higher than control group that of 0.27±0.04, there was statistically significant difference (F values were 14.77, 25.74, P < 0.001); wild-type cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.69±0.03) was 1.06 times higher than the control group (0.65±0.07), heterozygous cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.99±0.04) was 1.55 times higher than the control group CCM3 expression levels (0.64±0.06), there was statistically significant difference (wild-type cells: F = 7.08, P = 0.012, heterozygous type cell: F = 13.49, P = 0.002).

CONCLUSIONCCM3 gene may play a role in lead-induced genetic toxicity of mouse embryonic fibroblasts, CCM3 gene-lead interactions effects on mouse embryonic fibroblasts cell toxicity.

Animals ; Apoptosis Regulatory Proteins ; DNA Damage ; Embryo, Mammalian ; Female ; Fibroblasts ; Genotype ; Male ; Membrane Proteins ; Mice ; Mice, Inbred Strains ; Micronuclei, Chromosome-Defective ; Organometallic Compounds ; Proto-Oncogene Proteins

OBJECTIVE: To predict the sensitizing potency and optimal sensitization dose of trichloroethylene( TCE) by an in vitro skin sensitization test on a human acute monocytosis cell line( THP-1).METHODS: THP-1 cells were cultured in vitro and exposed to 2,4-dinitrochlorobenzene( DNCB),sodium dodecyl sulfate( SDS),tert-butylhydroquinone( tBHQ)and TCE for 24 hours.Flow cytometry was used to detect the expression of cell surface marker such as cluster of differentiation( CD) 86 and CD54,and the optimal dose range for sensitization detection was determined.With the relative fluorescence intensity( RFI),CD86 ≥ 150 and CD54 ≥ 200 as the standard,the sensitizing potency and optimal sensitization dose of TCE were predicted.RESULTS: The concentration range of reagents for sensitization test on THP-1 cells was the dose range at which the relative cell survival rate reached 75.0%-100.0%.DNCB at the doses of 20.83,25.00 and 30.00 μmol/L,tBHQ at the dose of 5.80 μmol/L,TCE at the doses of 8.33,10.00 and 12.00 mmol/L,can cause sensitivity.SDS was recognized as a negative sensitizer.The expression of CD86 and CD54 was the highest when the concentration of TCE was 8.33 mmol/L,which was considered as the best sensitization dose.CONCLUSION: The optimum sensitization dose of TCE is 8.33 mmol/L,which can provide the basis for dose design in future study of TCE sensitization pathways.

OBJECTIVE: To explore the molecular mechanism underlying 1,2-dichloroethane(1,2-DCE) induced apoptosis by screening differentially expressed proteins in human astrocytes( HAs). METHODS: HAs were cultured in complete medium with 1,2-DCE at various concentrations of 0-80 or 0-40 mmol/L. After 24 hours,apoptosis of HAs was evaluated using flow cytometry and staining with annexin Ⅴ-fluoresce in isothiocyanate and propidium iodide. An AAH-APO-1-2 protein chip was used to screen differentially expressed proteins and quantitative real-time polymease chain reaction(qRT-PCR) was used to verify related differentially expressed genes(DEGs). RESULTS: At 1,2-DCE concentrations of0-80 mmol/L,the total apoptosis rate of HAs increased with 1,2-DCE concentrations in a dose-dependent manner( P <0. 01). Seven different kinds of proteins were screened out by apoptotic protein chip. Among them,the expression of insulin-like growth factor-binding protein( IGFBP)-1,IGFBP-4 and cytochrome C( Cyto C) were up-regulated,while the expression of P27,cysteine aspartic acid specific protease-3( Caspase-3),B-cell lymphoma-2 interacting mediator of cell death( BIM) and BH3 interacting domain death agonist( BID) were down-regulated compared with the control group. The result of DEGs verified by qRT-PCR showed that the expression of mRNA of IGFBP-1,IGFBP-4 and Cyto C at 1,2-DCE concentrations of 40 mmol/L was up-regulated. This result was in consistent with the trend of target expression in the protein chip. The mRNA expression of Caspase-3,BIM and BID was also up-regulated. CONCLUSION: 1,2-DCE induces apoptosis of HAs through mitochondrial pathway.