Assessment of chemical mixtures using biomarkers of combined biological activity: A screening study in human placentas Rodríguez Carrillo, Andrea Mustieles Miralles, Vicente Vela Soria, Fernando Molina Molina, José Manuel Olea Serrano, Nicolás Fernández Cabrera, Mariana Fátima Endocrine disruption Chemical mixtures Biomarkers Combined effect Bioassay Placenta Reproduction HBM4EU The authors thank the European Union’s Horizon 2020 research and innovation programme HBM4EU under Grant Agreement No. 733032 for its financial support. Vicente Mustieles and Stephan Couderq are under contract within the HBM4EU project. Additionally, we acknowledge the Biomedical Research Networking Center-CIBER de Epidemiología y Salud Pública (CIBERESP), and the Instituto de Salud Carlos III (ISCIII) (FIS-PI16/01820 and FIS-PI16/01858). The authors also thank the ISCIII and “Fondo Europeo de Desarrollo Regional” (ISCIII/FEDER) for the Sara Borrell postdoctoral research contract granted to F. Vela-Soria (grant no. CD17/00212), and the Spanish Ministry of Education for the predoctoral fellowship (FPU) granted to A. Rodríguez-Carrillo (FPU 16/03011). This article will be part of the doctoral thesis developed by Andrea Rodríguez-Carrillo in the context of the “Clinical Medicine and Public Health Program” of the University of Granada (Spain). The authors gratefully acknowledge the technical assistance of Birgitte Møller Plesning. Humans are simultaneously exposed to complex mixtures of chemicals with limited knowledge on potential health effects, therefore improved tools for assessing these mixtures are needed. As part of the Human Bio-monitoring for Europe (HBM4EU) Project, we aimed to examine the combined biological activity of chemical mixtures extracted from human placentas using one in vivo and four in vitro bioassays, also known as biomarkers of combined effect. Relevant endocrine activities (proliferative and/or reporter gene assays) and four endpoints were tested: the estrogen receptor (ER), androgen receptor (AR), and aryl hydrocarbon receptor (AhR) activities, as well as thyroid hormone (TH) signaling. Correlations among bioassays and their functional shapes were evaluated. Results showed that all placental extracts agonized or antagonized at least three of the above-mentioned endpoints. Most placentas induced ER-mediated transactivation and ER-dependent cell proliferation, together with a strong inhibition of TH signaling and the AR transactivity; while the induction of the AhR was found in only one placental extract. The effects in the two estrogenic bioassays were positively and significantly correlated and the AR-antagonism activity showed a positive borderline-significant correlation with both es-trogenic bioassay activities. However, the in vivo anti-thyroid activities of placental extracts were not correlated with any of the tested in vitro assays. Findings highlight the importance of comprehensively mapping the bio-logical effects of ?real-world? chemical mixtures present in human samples, through a battery of in vitro and in vivo bioassays. This approach should be a complementary tool for epidemiological studies to further elucidate the combined biological fingerprint triggered by chemical mixtures. 2021-04-26T08:46:20Z 2021-04-26T08:46:20Z 2021-01-11 journal article Andrea Rodríguez-Carrillo, Anna Kjerstine Rosenmai, Vicente Mustieles, Stephan Couderq, Jean-Baptiste Fini, Fernando Vela-Soria, Jose Manuel Molina-Molina, Patricia Ferrando-Marco, Maria Wielsøe, Manhai Long, Eva Cecilie Bonefeld-Jorgensen, Nicolás Olea, Anne Marie Vinggaard, Mariana F. Fernández, Assessment of chemical mixtures using biomarkers of combined biological activity: A screening study in human placentas, Reproductive Toxicology, Volume 100, 2021, Pages 143-154, ISSN 0890-6238, [https://doi.org/10.1016/j.reprotox.2021.01.002] http://hdl.handle.net/10481/68103 10.1016/j.reprotox.2021.01.002 eng info:eu-repo/grantAgreement/EC/H2020/733032 http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Elsevier