Research On The Ecological Toxicity Of Typical Polyfluorinated Compounds

The maintenance of ecosystem stability and the security of human health Which is casued by the global pollution of the PFASs have become the focus of the study on the natural environment filed.The study to evaluate its health risks,to study its toxic mechanism,to explore the monitoring,control and inspection of perfluorochemicals pollution is a hot spot in the continuous.In this study,the molecular mechanism of toxicity of the typical perfluorinated compounds was investigated under the simulating physiological conditions.In addition,ecotoxicology,cell biology,biochemistry and molecular biology and other interdisciplinary means were used in this paper.The ecotoxicological effects of the typical perfluorinated compounds was investigated at the cell level,protein level and gene level..There are seven parts in this paper:1 The binding parameters of three kinds of perfluorinated compounds(PFOA,PFOS-k,POSF)and bioactive macromolecules(HSA / CtDNA)was determined by ultraviolet spectrophotometry,The parameters indicated that the interaction between PFOA/PFOS-k/POSF-HSA was moderate.2 The results from fluorescence quenching spectrum indicated that PFOA could bind to HSA to form static complex;the obtained thermodynamic parameters manifested that the main interactional force between PFOA-HSA is mainly hydrophobic force;the fluorescence polarization proved that PFOA and HSA generated non-covalent complex by interaction.3 The interaction between dimethyl phthalate(PFOA/PFOS-k/POSF)and serum albumin(HSA)were investigated by capillary electrophoresis(CE)and the analysis methods were established.The binding models of PFOA/PFOS-k/POSF(as the ligand)to BSA(as the receptor)were prepared.Plug-plug kinetic method(PPK),Hummel-Dreyer method(HD),Mobility method were used to explore the interaction parameters of the PFOA/PFOS-k/POSF-HSA system.Scatchard,Klotz and Non-linear regression equations were adopted to obtain interaction parameters of the interactional system.According to the obtained interaction parameters,all the regression method equation for this system can be used to analyze the PFOA/PFOS-k/POSF-HSA system.The binding parameters indicated that the interaction between PFOA/PFOS-k/POSF-HSA had moderate intensity,which had only one type of binding sites.4 The molecular docking of PFOA / PFOS-k / POSF-HSA system was carried out by computer simulation technology.The binding site of PFOA / PFOS-k / POSF on HSA and the type of intra-system force are theoretically revealed.The mechanism of interaction between PFSA / PFOS-k /POSF on HSA is visually clearly presented at the molecular level.The results are consistent with the previous results of spectroscopy and capillary electrophoresis,and there is moderate effect in the system,and the main force is the hydrophobic interaction.5 The effect of PFOA / PFOS-k / POSF on SMMC-7721 hepatocarcinoma cells was observed by morphological method.The results showed that PFASs had significant cytotoxic effect on cells.Thetoxic effects of PFASs have a dose-response relationship by MTT colorimetric assay.The results of flow cytometry showed that the number of apoptotic cells increased with the increase of PFOA concentration.The results were consistent with the previous morphological and MTT results.6 The toxicity of perfluorinated compounds at the level of cell-active protein was studied by Western blot.The expression of Bax protein and Bcl-2 protein in the cells was significantly abnormal.After SMMC-7721 cells were treated with different concentrations of PFOA / POSF,The experimental results showed that perfluorinated compounds may interfere with normal protein expression in cells.7 The toxicity of perfluorinated compounds is further explored at the gene level.After SMMC-7721 cells were treated with PFOA,The expression of Bax mRNA and Bcl-2 mRNA was significantly different by real-time fluorescence quantitative assay.Bax mRNA expression was up-regulated and Bcl-2 mRNA expression was down-regulated.The expression of Bcl-2 and Bax in the cells reflect that perfluorinated compounds may have the ability to affect the normal gene expression directly.