Enantioselectivity in transplacental transfer of perfluoro-1-methylheptanesulfonate (1m-PFOS): Human biomonitoring and in silico study

Lu Zhao; Fangfang Chen; Shanshan Yin; Jingqian Xie; Muhammad Aamir; Shuren Liu; Weiping Liu

doi:10.1016/j.envpol.2020.114136

Enantioselectivity in transplacental transfer of perfluoro-1-methylheptanesulfonate (1m-PFOS): Human biomonitoring and in silico study

Environ Pollut. 2020 Jun:261:114136. doi: 10.1016/j.envpol.2020.114136. Epub 2020 Feb 10.

Authors

Lu Zhao¹, Fangfang Chen¹, Shanshan Yin¹, Jingqian Xie², Muhammad Aamir¹, Shuren Liu¹, Weiping Liu³

Affiliations

¹ MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
² College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
³ MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: wliu@zju.edu.cn.

PMID: 32066055
DOI: 10.1016/j.envpol.2020.114136

Abstract

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_1m-PFOS 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_1m-PFOS was correlated in maternal sera, but not in cord sera and placentas. These data indicated that %br-PFOS and EF_1m-PFOS 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.

MeSH terms

Alkanesulfonic Acids*
Animals
Biological Monitoring
China
Female
Fluorocarbons*
Humans
Mothers
Placenta
Pregnancy
Stereoisomerism

Substances

Alkanesulfonic Acids
Fluorocarbons