| Objectives The purpose of this study is to elucidate theimpact of key metal components in the PM2.5 component on the maintenance of neuroimmunological balance by blood cerebrospinal fluid barrier,in order to provide a theoretical basis for the prevention and control of environmental pollutants.Methods The medium flow sampler(cutting particle size Da50=(2.5±0.2)μm)was used to collect PM2.5 sample in the atmosphere from January to December in Tangshan City.The contents of 12 metals and metal-like elements in PM2.5 were detected by inductively coupled plasma mass spectrometry ICP-MS,indcluding Lead(Pb),manganese(Mn),arsenic(As),chromium(Cr),nickel(Ni),selenium(Se),antimony(Sb),cadmium(Cd),antimony(Tl),antimony(Be),Mercury(Hg).A metal with high content and/or high toxicity was selected as artificial PM2.5 metal components and carbon black(CB)as carbon core.The dose of carbon black and lead was made according to according to the annual average limit of PM2.5 secondary environment and the ratio of the weighted average of the metal content in PM2.5 of Tangshan City.The perform of making artificial PM2.5 metal components included fully mixing,rotating as well as blow drying.The feature including hydrodynamic particle size distribution and water contact angle of the prepared samples were examined.The particle size,distribution,aggregation and structural morphology of Pb+CB and CB particles were observed by SED.Rat choroid plexus epithelial cells line Z310 in logarithmic growth phase were divided into four groups,control group,Pb treatment group(0.638μg/ml lead acetate),BC group(9.899μg/ml CB),and Pb+CB group(10μg/ml Pb+CB),and the cell exposure periods was 12h.The effect of particulate matter on cell proliferation or growth was examined using a CCK-8 kit,and as a result,cytotoxicity was expressed in terms of cell survival rate.The protein expressions of ICAM-1,VCAM1,MadCAM-1 and monocyte chemotactic factors MCP-1,IL-8 and MIP-3a in Z310 cells were detected by Western Blot.Results 1The concentration of 11 detected elementals in fluctuated along different months,of which the highest content of Pb and Mn.The average concentration of Pb was232.23ng/m~3,and the Mn concentration was 143.96ng/m~3 of PM2.5.The content of Pb,Cd and As were significantly higher in winter than that in spring,summer and autumn(P<0.05).2 The top one element in terms of concentration change was Pb,which is selected as metal component of artificial PM2.5.3 The artificial PM2.5 was synthesis based on The average annual limit of secondary environment of PM2.5(35μg/m~3)and the 2 folds of average Pb content in PM2.5 of Tangshan City in 2017(464.46 ng/m~3)and the synthetic ratio of Pb+CB was lead(464.46 ng)/CB(35μg)(1:75.36.)4 Compared with CB,the hydrodynamic particle size and contact angle of Pb+CB did not change,and the difference was not statistically significant(P>0.05).5 The Pb+CB particleand CB particles were nano-scale spherical,uniform distribution,loose structure and void structure.6 The survival rate of Z310 with 10μg/ml Pb was 96.7%,10μg/ml CBfor95.6%and 10μg/ml Pb+CBwas of86.8%.7The protein expressions of ICAM-1,VCAM-1 and MadCAM-1 in Pb+CB group were significantly higher than those in Pb and CB treatment alone,and the difference was statistically significant(P<0.05).Compared with the control group,the proteinsexpression of ICAM-1,VCAM-1 and MadCAM-1 in CB group weresignificantly increased(P<0.05).8Compared with the control group,the proteins expression of the characteristic chemokine MCP-1 ofthe cells inPb group and CB group weresignificantly increased,and the protein expression of MCP-1 in the Pb+CB group was also significantly higher than that of the Pbtreatment group orthe CB group(P<0.05).The protein expression of IL-8 and MIP-3a related to MadCAM-1 expression werenot significantly different in the cells exposed to PborCB(P>0.05).However,the expression of IL-8 and MIP-3a in Pb+CBgroup was significantly higher than that of Pbor CB alone treatment(P<0.05).Pb and CB exposure factors interact with MCP-1,IL-8 and MIP-3a protein expression(F=11.638,P=0.009.F=1104.5,P<0.001.F=2112.5,P<0.001).Conclusions The concentration of Pb and Mn in the metal components of PM2.5 in tangshan in 2017 was the most prominent,and As and Cr followed.The poisoning of carbon black and lead particles in PM2.5 has a synergistic effect on the damage of proteins regulating monocytes entering the central nervous system in the blood-cerebrospinal fluid barrier.Figure 12;Table 10;Reference 70... |
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