Proteomic Profiling of Xenobiotic and Nutrient Transporters in Human Placenta of Different Gestational Ages

The placenta serves a critical role in nutrient uptake and waste elimination for the developing fetus. The placenta is also responsible for the uptake and/or exchange of xenobiotics, including medications, between the maternal and fetal bloodstreams. An estimated 40-80% of women take medications or drugs during pregnancy. Very little is understood about fetal drug and nutrient exposure during pregnancy and how it may change over the course of fetal development. This study aimed to characterize the abundance of transport proteins in placental tissue, which are important in modulating fetal nutrient and drug exposure, over the duration of pregnancy. Using a mass spectrometry-based global proteomic approach, the relative abundance of proteins in placental tissue samples was profiled from first trimester, second trimester, and term placenta samples. Our analysis detected a total of 6331 proteins which included a total of 139 solute carrier and ATP-binding cassette transport proteins that were detected across the dataset, and 80 that were quantified in every sample. In general, membrane-associated proteins, including solute carrier and ATP-binding cassette transport proteins, were significantly enriched in placental tissue collected during early gestation compared to term placental tissue. Overall, this study presents a comprehensive profiling of membrane-associated proteomic changes during gestation and identifies significant gestational age associated abundance changes at the protein level in several transport protein families. These data provide critical information to support future studies into the understanding of fetal exposure to xenobiotics and nutrients circulating in the maternal bloodstream.