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OBJECTIVE：To discuss the inhibitory effect of lanthanum chloride on the calcification of vascular smooth muscle cells（VSMCs）induced by high phosphorus and its mechanism. METHODS ：On the basis of screening the action concentration and time of lanthanum chloride by MTT method ，human VSMCs were divided into control group （1 mmol/L phosphorus solution ）， lanthanum chloride high concentration control group （1 mmol/L phosphorus solution+ 60 μmol/L lanthanum chloride），model group （3 mmol/L phosphorus solution ），sodium chloride group （3 mmol/L phosphorus solution+ 180 μmol/L sodium chloride），nuclear factor κB（NF-κB）signaling pathway agonist+lanthanum chloride group （3 mmol/L phosphorus solution+ 1 μg/mL lipopolysaccharide+ 60 μmol/L lanthanum chloride），positive control group （3 mmol/L phosphorus solution+ 100 μmol/L sodium pyrophosphate），and lanthanum chloride low ，medium，and high concentration groups （3 mmol/L phosphorus solution+ 15，30，60 μmol/L lanthanum chloride）. Alizarin red S staining and Von Kossa staining were used to detect cell calcification in each group after treated with phosphorus solution for 6 d and relevant medicine for 2 d. Western blot assay was used to detect the protein expression of TNF-α receptor associated protein 6（TRAF6），nuclear factor κB inhibitor protein α（IκBα），NF-κB p65，bone morphogenetic protein 2 （BMP-2），smooth muscle 22 α（SM22α）and Runt related transcription factor 2（Runx2）. Real-time fluorescence quantitative polymerase chain reaction was used to detect mRNA expression of TRAF 6，IκBα，BMP-2，SM22α and Runx2. RESULTS ： Compared with control group ，no cell calcification was observed in the lanthanum chloride high concentration control group ，while obvious cell calcification and significant increase of OD value were observed in model group and sodium chloride group （P＜ 0.01）；protein and mRNA expression of TRAF 6 and BMP- 2 in cytoplasm as well as mRNA expression of Runx 2，protein expression of NF-κB p65 and Runx 2 in nucleus were significantly increased （P＜0.01）；protein and mRNA expression of IκBα and SM22α as well as protein expression of NF-κB p65 in cytoplasm were significantly decreased （P＜0.01）. Compared with model group，cell calcification was significantly improved in lanthanum chloride groups and positive control group ，while OD values were significantly reduced ；the expression levels of the above-mentioned protein and mRNA were reversed to varying degrees （P＜0.05 or P＜0.01）. Compared with lanthanum chloride high concentration group ，obvious cell calcification was observed in NF-κB signaling pathway agonist + lanthanum chloride group ，and OD value was significantly increased ；the above indexes were significantly reversed in cytoplasm and nucleus （P＜0.05 or P＜0.01）. CONCLUSIONS ：Lanthanum chloride can inhibit the calcification of VSMCs induced by high phosphorus ，and its mechanism may be related to the inhibition of NF-κB signaling pathway activation.
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Objective@#To understand the pollution characteristics and assess the pollution health risks of heavy metals in atmospheric PM2.5 in Lanzhou.@*Methods@#According to the regional characteristics of air pollution and industrial distribution characteristics in Lanzhou, atmospheric PM2.5 was sampled monthly in Chengguan and Xigu Districts from January, 2015 to December, 2016. Detected the concentration of PM2.5 and 12 kinds of elements (Sb, Al, As, Be, Cd, Cr, Hg, Pb, Mn, Ni, Se and Tl) by weighing method and inductively coupled plasma mass spectrometry. Enrichment factor and geo-accumulation index were used to describe the pollution characteristics, while health risk assessment was conducted using the recommended United States Environmental Protection Agency (USA EPA) model. The health risks of non-carcinogens were evaluated by non-cancer hazard quotient (HQ), the non-carcinogenic risk was considered to be negligible when HQ<1, HQ>1 meant a health risk. With a single contaminant cancer Risk value to evaluate the health risks of carcinogens, when the Risk value between 10-6 to10-4 as an acceptable level.@*Results@#The daily average concentrations of PM2.5 was 83.0 μg/m3, 77.0 μg/m3 in Chengguan and Xigu Districts, respectively, during the sampling periods, and the concentration of PM2.5 in winter/spring was higher than summer/fall in both districts. The concentration of Al in PM2.5 was the highest and other elements in descending order: Pb, Mn, As, Sb/Cd, Tl in both districts. Enrichment factor results showed that Al and Mn were mainly affected by natural factors, the rest of five elements were all typical man-made pollution elements and according to geo-accumulation index pollution level of Cd was the strongest in the winter. The results of health risk assessment showed that Mn had the highest non-cancer risks (HQ>1) and affected the health of the children seriously. HQ reached up to 2.44 and 1.79 in Chengguan and Xigu Districts, respectively. Pb, As, Sb, Cd had slight health impact (HQ<1), could be negligible. The cancer risks range of As, Cr were 6.33×10-6 to 6.46×10-5 between the acceptable level of risk (10-6 to 10-4), which indicated that As and Cd had potential cancer-risks.@*Conclusions@#The pollution level of atmospheric PM2.5 and the heavy metals in it was still grim;the non-cancer risks caused by multiple metals on children deserved attention. Although the cancer risks of As and Cd were between the acceptable level of risk, the potential cancer risk still shall not be ignored.