稀土暴露对人外周血单个核细胞端粒酶及细胞凋亡的影响

Effects of rare earth compounds on human peripheral mononuclear cell telomerase and apoptosis

目的 探讨稀土暴露对正常人外周血单个核细胞的端粒酶活性及细胞凋亡的影响。方法 选取我国最大的离子吸附型稀土矿江西省寻乌县稀土矿区矿工 (一线作业 8年以上 ) 30名健康成人为调查对象 ,同时选取地质结构和社会经济特征基本相同的离矿区 35km外的寻乌县另一村居民 30名健康成人作为对照。运用电感耦合等离子体 质谱法对随机选取的暴露组和对照组进行血稀土含量测定。端粒酶重复扩增法和流式细胞仪检测稀土暴露和正常人群的单个核细胞端粒酶活性和细胞凋亡以及细胞周期变化。结果 血稀土含量镧 (La)暴露组为 (1 2 6 85± 1 0 70 5 ) μg/L ,对照组(0 1717± 0 2 0 6 1) μg/L。暴露组与对照组比较La、铈 (Ce)、镝 (Dy)、钇 (Y)、镨 (Pr)、钕 (Nd)、钐 (Sm)、钆 (Gd)、镱 (Yb)具有统计学意义 ;暴露组的总血稀土含量与对照组相比有统计学意义。端粒酶活性检测结果阳性率暴露组为 37 0 % (11/ 30 ) ,对照组为 16 7% (5 / 30 ) ,两组比较有统计学意义。暴露组平均年龄为 (38 6 9± 8 0 2 )岁 ,对照组平均年龄为 (40 4 5± 9 0 2 )岁 ,两组年龄无统计学意义。端粒酶活性与血总稀土含量有高度相关性。暴露组和对照组外周血单核细胞的凋亡率比较 ,没有统计学意义 ,但在细胞周期分析中 ,暴露组与对照?

Objective To study the effects of rare earth exposure on human telomerase and apoptosis of human peripheral mononuclear cells (PBMNs). Methods Rare earth mine lot in Xunwu county,the biggest ion absorptive rare earth mine lot of China,was selected as the study site. Another village of Xunwu county,with comparable geological structure and social environment was selected as the control site. Thirty healthy adults were randomly selected from the study site as exposure group and another 30 healthy adults randomly selected from the control site as control group.The blood content of 15 rare earth elements,including La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu and Y,were determined by inductive coupled plasma-source mass spectrometry (ICP-MS).The total contents of rare earth elements in the blood were calculated. The TRAP and FCM assays were carried out to analyse the telomerase and apoptosis of human PBMNCs respectively. Results In the exposure group,the concentration of La,Ce,Dy and Y were significantly higher ( P <0.001),and Pr,Nd,Sm,Gd and Yb were higher than those in the control group ( P <0.05).The total content of rare earth in the blood of exposure group showed significant difference compared with control group ( P <0.001). Telomerase activity in PBMNs of the exposure group was higher than that in the control group( P <0.05);there were 11 adults in the exposure group (30 adults) and 5 adults in control group(30 adults)showed positive telomerase activity. The average age of the exposure group was (38.69±8.02) years-old,while the control group was (40.45±9.02) years-old ( P >0.05).It was found that there was a significant relationship between telomerase activity and the total content of rare earth elements( P <0.01). 3.The proportion of apoptosis was not different between the two groups ( P >0.05),but the cells in the S-phase and G 2-M phase were increased ( P <0.01) in the exposed group. Conclusion The telomerase activity of PBMNs in the rare earth elements exposed group was higher than that of the control group,and there is no effect on apoptotic rate of PBMNs,but may promote the diploid DNA replication,and increase the percentage of G 2/M and S phase cells.