Repeated measures of prenatal thallium exposure and placental inflammatory cytokine mRNA expression: The Ma'anshan birth cohort(MABC)study

Highlight：首次在中国孕妇人群中报道不同孕期钛暴露引起胎盘炎性因子分泌，对孕期防护提供数据支持。

Abstract

Thallium(Tl), a ubiquitous environmental toxicant, can cross the placental barrier during pregnancy. However, the effects of prenatal Tl exposure on placental function are currently unclear. Based on the Ma’anshan Birth Cohort study, we examined whether long-term prenatal Tl exposure was associated with placental inflammation. Tl concentrations were quantified in serum samples(n ¼ 7050)from 2515 pregnancy during each trimester, placental inflammatory cytokine mRNA expression was assessed in 2519 placenta tissues. Geometric mean values of serum Tl concentrations were 63.57, 63.63 and 48.71 ng/L for the first, second and third trimesters, respectively. After adjustment for potential confounders, serum Tl concentration was positively associated with CD68(b: 0.30; 95%CI: 0.05, 0.56)in the first trimester and TNF-a(b: 0.12; 95%CI: 0.01, 0.23), IL-6(b: 0.15; 95%CI: 0.05, 0.25)and CD68(b: 0.25; 95%CI: 0.10, 0.39)in the third trimester, however was negatively associated with IL-4(b: 0.21; 95%CI: 0.41, 0.01)and CD206(b: 0.23; 95% CI: 0.45, 0.02)in the first trimester. Repeated measures analysis showed that TNF-a, IL-6 and CD68 increased by 0.1 1(95% CI: 0.01, 0.21), 0.12(0.15, 95% CI: 0.05, 0.25), 0.22(95% CI: 0.10, 0.39), respectively, with each 1ln-transformed Tl increase in total samples. Gender-specific analyses revealed that these associations were largely driven by male offspring. In addition, immunohistochemistry revealed that nuclear NF-kB p65 expression increased in placenta tissue. The results of this prospective cohort study provide longitudinal evidence that prenatal Tl exposure induces a placental inflammatory response in the Chinese population.

Zhu YD, Liang CM, Hu YB, Li ZJ, Wang SF, Xiang HY, Huang K, Yan SQ, Zhu P, Liu P, Tao FB*. Repeated measures of prenatal thallium exposure and placental inflammatory cytokine mRNA expression: The Ma'anshan birth cohort(MABC)study. Chemosphere, 2020, 246:125721.