Fetal Membranes Contribute to Drug Transport across the Feto-Maternal Interface Utilizing the Breast Cancer Resistance Protein (BCRP)

Abstract

During pregnancy, the placenta is established as a primary organ for drug transport at the maternal-fetal interface. The fetal membranes (FM) also form an interface with maternal tissues; however, their role in drug transport has not been previously investigated. Knowledge of drug transport across this feto-maternal interface along with the placenta can improve new drug development and testing for use during pregnancy. We also hypothesize that extracellular vesicles (exosomes 30–160 nm) released from the FM and placental cells may also contain drug transport proteins and might impact drug trafficking across the feto-maternal interfaces. The objectives were to (1) localize the breast cancer resistance protein (BCRP) in human FM; (2) determine the drug transport function of BCRP in chorion trophoblast cells (CTCs) of the FM; and (3) investigate the presence of BCRP in FM cell-derived exosomes, as a paracrine modifier of the tissue environment for transport functions. The gene and protein expressions of ABCG2/BCRP in FMs were determined by quantitative real-time PCR (qRT-PCR) and western blotting (WB) and were localized by immunohistochemistry (IHC). The surface expression of BCRP in FM cells was determined by flow cytometry. The functional role of BCRP was assessed by an EFFLUX dye multidrug resistance assay. The presence of BCRP in exosomes derived from CTCs and BeWo cells was examined using ExoView®. Data derived from CTCs are compared with placental trophoblast cells (BeWo). BCRP is expressed and localized in the fetal membrane, primarily in the chorion trophoblast cell layer and scarcely in the amnion epithelial layer (AEC), and primarily localized on both AEC and CTC cell surfaces. Efflux assay data showed that FM cells have similar drug resistance activity as BeWo cells, suggesting that FM also have drug transportation capabilities. BeWo- and CTC-derived exosomes expressed limited BCRP protein on the surface, so it was predominantly contained in the exosomal lumen. As far as we are aware, this is the first study to report BCRP expression in fetal membrane cells and as cargo in fetal membrane-derived exosomes. We report that fetal membrane cells are capable of drug transportation. Based on these results, investigational drug trials should include the FM and its exosomes as possible drug transportation routes in pregnancy.

Testing of drugs using human feto-maternal interface organ-on-chips provide insights into pharmacokinetics and efficacy

“…Our recent findings have shown the functionally active transporter proteins including phosphoglycoprotein-1, breast cancer receptor protein-1, and organic anion transporter proteins in fetal membranes. 12,13 Current study has shown the protein and gene expression of several active influx and efflux transporters proteins and active cytochrome 3A4 enzyme capable of metabolizing drug molecules, in human fetal membrane cell lines (data in press). Therefore, simultaneous testing of both FMis will be necessary to fully understand the effect of a drug's potential impact during pregnancy.…”

“…Our recent findings have shown the functionally active transporter proteins including phospho-glycoprotein-1, breast cancer receptor protein-1, and organic anion transporter proteins in fetal membranes. 12,13…”

The role of fetal membranes during gestation, at term, and preterm labor

“…[13,19] A few of these transporter proteins include permeability-glycoprotein (P-gp), breast cancer resistance protein-1 (BCRP-1), and the organic anion transporting polypeptide 2B1 (OATP2B1) were primarily localized in the chorion with limited expression in the amnion. [12,13] Their expression and function in the fetal membranes are similar to that observed in the placenta, changing the dogma that the placenta is the only intrauterine organ responsible for molecule transport. [12] Further studies and a better understanding of this drug transportation route may lead to novel therapeutic approaches and innovative drug therapies during pregnancy.…”

“…[12,13] Their expression and function in the fetal membranes are similar to that observed in the placenta, changing the dogma that the placenta is the only intrauterine organ responsible for molecule transport. [12] Further studies and a better understanding of this drug transportation route may lead to novel therapeutic approaches and innovative drug therapies during pregnancy. This is critical, as a breakdown of the homeostatic processes of the fetal membranes described above leads to catastrophic membrane failure.…”

Emerging Roles of Endocannabinoids as Key Lipid Mediators for a Successful Pregnancy

“…If this phenomenon occurs at the maternal–fetal interface is still unclear, but we cannot exclude the possibility that some phytocannabinoids could have a higher local relevance than previously suspected and that Cannabis may affect placental permeability towards other phytochemicals and toxicants, especially in case of polysubstance abuse by pregnant women. Being that the BCRP/ABCG2 efflux transporter is highly expressed on the apical surface of syncytiotrophoblasts, where it modulates the trafficking of toxicants from maternal circulation to the developing fetus during prenatal growth [ 145 ], its downregulation could expose the fetus to detrimental effects of the xenobiotics, including Cannabis constituents.…”