Neurodevelopmental Toxicity Of M-tolyl Methylcarbamate In Vitro Study

Background m-tolyl methylcarbamate(MTMC)is one of carbamates pesticide, human are exposed to MTMC from various environmental sources. It was well known that acute and high dosage MTMC can produce acute toxicity. Recent study had showed that chronic and low dosage exposured to MTMC seemed to be more at risk for recognization, psychology deficts, developing Parkinson's disease and other neurodegenerative disease. But chronic and low dosage exposured to MTMC that induced neural developmental toxicity is still unknown and unconcern.Objective N2a neuroblastoma cells and C6 glioma cells were cultured as neuron and glial precursor model respectively,and the primary culture of mouse embryonic neural stem cells was used for neural stem cells model. They were all used to explore the effect of MTMC on their proliferation and the differences of their sensibility to MTMC;On this basis, to explore the effect of MTMC on migration,differentiation of mouse neural stem cells.Methods N2a neuroblastoma cells and mouse embryonic neural stem cells were exposed to MTMC(5,25,50,100mg/L)for 12,24,36 hours. C6 glioma cells were explored to MTMC(5,25,100mg/L)for 12,24,36 hours either. The proliferation of N2a neuroblastoma cells , mouse embryonic neural stem cells and C6 glioma cells were examined by MTT assay. The migration of mouse embryonic neural stem cells after 24h exposure to MTMC(1,5,25mg/L)and the differentiation after 36h exposure to MTMC(1,5,25mg/L)were determined by immunofluorescence cytochemistry staining.Statistical treatment The data was analyzed with SPSS 13.0Results MTT results showed that the three different cells have different sensitive degrees to MTMC on proliferation inhibition. Mouse embryonic neural stem cells were especially sensitive to MTMC:â‘ After 12h exposure , MTMC, at the doses in this test, had no significant effect on N2a and C6 cells; Except 5mg / L, the remaining doses of MTMC significantly inhibited the proliferation of mouse embryonic neural stem cells (P<0.05);â‘¡After 24h exposure, 100mg / L MTMC significantly inhibited the proliferation of N2a cells; Except 5mg / L, the remaining doses of MTMC significantly inhibited the proliferation of C6 cells (P<0.05); MTMC, at the doses in this test, significantly inhibited the proliferation of mouse embryonic neural stem cells (P<0.05).â‘¢After 36h exposure, Except 5mg / L, the remaining doses of MTMC significantly inhibited the proliferation of N2a cells (P<0.05); MTMC, at the doses in this test, significantly inhibited the proliferation of C6 cells and mouse embryonic neural stem cells (P<0.05).Immunofluorescence cytochemistry staining results showed that 5, 25 mg / L MTMC did not affect neural cells migration, 100mg / L MTMC significantly reduced neurospheres Dm (the longest transfer distance) / Db (the ball diameter before transfer) values (P < 0.05); 25mg / L MTMC significantly decreased the proportion of the TUJ-positive cells (P <0.05); 1, 5, 25 mg / L MTMC significantly decreased the proportion of GFAP-positive cells (all P <0.05).Conclusions In the dose range of this study, the three different cells have different sensitive degrees on proliferation inhibition by MTMC, mouse embryonic neural stem cells were most sensitive, followed by C6 glioma cells. MTMC was able to inhibit mouse embryonic neural stem cells from differentiating to neurons and glial cells. Especially at the low dose,It significantly inhibited neural stem cells from differentiating to glial cells. These results suggested that the neurodevelopmental toxicity caused by intrauterine exposure to MTMC was probably by affecting cell proliferation and differentiation or other key elements.