Genotoxic Effects And Mechanism Of Typical Neonicotinoids On Human Bone Marrow Mesenchymal Stem Cells

The usage amount of neonicotinoids(NEOs)insecticides is the largest in the global insecticide market because of the high efficiency and wide spectrum.However,studies have shown that this class of insecticide has toxic effects on non-target organisms such as bees,birds and even mice,with its potential harm to human health remaining unclear.Three representative compounds,imidacloprid(IMI),nitenpyram(NIT)and acetamiprid(ACE)were selected to study their genotoxicity and mechanism on the human bone marrow mesenchymal stem cells(HBMSCs)at cell and molecular level.The main results are as follows,(1)The comet assay was used to detect the genotoxicity of NEOs.The results showed that in the range of exposure concentration of NEOs(12.5-100 ?g/m L),three compounds significantly aggravated the damage degree of DNA in a dose-dependant manner and increased comet TailDNA%,tail length(TL)and Olive tail moment(OTM).The TailDNA%,TL and OTM in the highest exposure group of IMI were 4.67,2.64 and 5.80 times of those in the control group,respectively.The TailDNA%,TL and OTM in the highest exposure group of NIT were 3.67,2.52 and 4.43 times of those in the control group,respectively.The TailDNA%,TL and OTM in the highest exposure group of ACE were 4.31,2.90 and 6.06 times of those in the control group,respectively.(2)The effect of three NEOs on the differentiation of HBMSCs were studied.The effects of NEOs on the biomarkers of osteogenic differentiation of HBMSCs were studied by the determination of alkaline phosphatase(ALP)activity and the staining of alizarin red on calcium nodules.The results showed that the three NEOs had no significant effects on ALP activity and caused a slight inhibition effect on the formation of calcium nodules.And the results of RT-qPCR suggest that IMI and ACE significantly down-regulated the mRNA expression of ALP.The effects of NEOs on the adipogenic differentiation of HBMSCs was studied by staining lipid drops with oil red O.The results showed that NEOs has a slight effect on the adipogenic differentiation of HBMSCs,with no abvious dose-effect relationship.(3)The molecular mechanisms of the genotoxicity of NEOs and other harmful effects on HBMSCs were studied by microarray analysis.The results showed that there were 339 differentially expressed genes in NEOs and nicotine,among which 230 genes were up-regulated and 109 genes were down-regulated.The GO functional classification of differentially expressed genes mainly includes cell growth,immunity,signal transduction,transcription and translation,metabolism,differentiation and development.The enrichedpathways of differentially expressed genes by KEGG include systemic lupus erythematosus,alcoholism,viral carcinogenesis,PI3k-AKT signaling pathway,transcriptional misregulation in cancer,biosynthesis of antibiotics,ECM-receptor interaction,bladder cancer and terpenoid backbone biosynthesis.It is suggested that the genotoxicity of NEOs may be the result of co-regulation of PI3K-AKT signaling pathway and other biological pathways.