MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
Environ Pollut. 2020 Jun;261:114136. doi: 10.1016/j.envpol.2020.114136. Epub 2020 Feb 10.
Perfluorooctane sulfonates (PFOS) are one of the most prominent perfluoroalkyl contaminants in humans and wildlife. Currently, information regarding enantiomer-specific exposure to PFOS in humans through transplacental transfer is lacking. This study examined 32 matched maternal serum, cord serum and placenta samples collected from mother-infant pairs in Wuhan, China. The enantiomer fraction (EF) value of perfluoro-1-methylhptanesulfonate (1m-PFOS) was lower in cord sera (0.362 ± 0.062, n = 23) compared to maternal sera (0.422 ± 0.048, n = 21) and placenta (0.410 ± 0.060, n = 16). Evaluations of the difference between EF suggested enantioselective transplacental transfer of 1m-PFOS. In silico evaluation of the binding affinity of 1m-PFOS to human serum albumin (HSA) showed that the two 1m-PFOS enantiomers enantioselectively interacted with the HSA. This result hints the enantioselective carrier protein affinity may be a key factor for stereoselective 1m-PFOS transplacental transfer. The percentage of branched PFOS (%br-PFOS) and EF was correlated in maternal sera, but not in cord sera and placentas. These data indicated that %br-PFOS and EF may be less reliable in identifying PreFOS exposure when it comes to complex biological processes, such as transplacental transport. This study could expand our understanding of stereoselective placental contaminant transfer in humans.
全氟辛烷磺酸 (PFOS) 是人体内和野生动物中最突出的全氟烷基污染物之一。目前，关于通过胎盘转移途径人类接触 PFOS 的对映体特异性的信息还比较缺乏。本研究在中国武汉采集了 32 对母 - 婴血清、脐带血清和胎盘样本，对这些样本进行了分析。全氟-1-甲基庚烷磺酸盐（1m-PFOS）的对映体分数（EF）值在脐带血清中较低（0.362±0.062，n=23），与母血清（0.422±0.048，n=21）和胎盘（0.410±0.060，n=16）相比。EF 值的评估表明 1m-PFOS 存在对映体选择性胎盘转移。对 1m-PFOS 与人血清白蛋白（HSA）结合亲和力的计算机评估显示，两种 1m-PFOS 对映体与 HSA 选择性相互作用。这一结果暗示对映体选择性载体蛋白亲和力可能是 1m-PFOS 对映体选择性胎盘转移的关键因素。母体血清中分支全氟辛烷磺酸（%br-PFOS）和 EF 呈正相关，但脐带血清和胎盘中没有。这些数据表明，在涉及复杂的生物过程（如胎盘转运）时，%br-PFOS 和 EF 可能不太可靠，无法准确识别 PreFOS 暴露。本研究可以增进我们对人类中立体选择性胎盘污染物转移的理解。
