Differential proteomic expression of human placenta and fetal development following e-waste lead and cadmium exposure in utero

ABSTRACT: Prenatal exposure to lead (Pb) and cadmium (Cd) has been associated with a series of physiological problems resulting in fetal growth restriction. We aimed to investigate the effects of Pb and Cd exposure on placental function and the potential mechanisms involved in fetal development. Placental specimens and questionnaires were collected from an e-waste area and a reference area in China. Two-dimensional electrophoresis combined with MALDI-TOF-MS/MS and molecular network relationship were performed to analyze differentially expressed proteins using a compositing sample pool. Compared with the reference group, the exposed group exhibited significantly higher levels of placental Pb and Cd (p < 0.01), shorter body length and higher gestational age (p < 0.01). After bivariate adjustment in a linear regression model, decreases of 205.05 g in weight and 0.44 cm in body length were associated with a 10 ng/g wt increase in placental Cd. Pb showed a negative trend but lacked statistical significance. Proteomic analysis showed 32 differentially-expressed proteins and were predominantly involved in protein translocation, cytoskeletal structure, and energy metabolism. Fumarate hydratase was down-regulated in the exposed placenta tissues and validated by ELISA. Alterations in placental proteome suggest that imbalances in placental mitochondria respiration might be a vital pathway targeting fetal growth restriction induced by exposure to Cd. - Highlights: • The placental Pb and Cd levels were higher in the e-waste polluted area. • Proteome in placenta tissues was performed by two-dimensional gel electrophoresis. • Cd exposure in the placenta was associated with the reduced fetal development. • 32 proteins covered in translocation, energy metabolism and cytoskeletal structure. • Dysregulated mitochondrial respiration may act in the Cd-reduced fetal development.