Full length article The impact of circulating exosomes derived from early and late onset pre-eclamptic pregnancies on inflammatory cytokine secretion by BeWo cells K. Maduray a, *, J. Moodley b , I. Mackraj a a School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, South Africa b Womens’ Health and HIV Research Group, University of KwaZulu-Natal, South Africa A R T I C L E I N F O Article history: Received 18 December 2019 Received in revised form 19 February 2020 Accepted 21 February 2020 Available online xxx Keywords: Pre-Eclampsia Exosomes Cytokines Placenta Pregnancy A B S T R A C T Objectives: The pathogenesis of pre-eclampsia (PE) is associated with significant maternal and neonatal complications, an increased inflammatory response, placental hypoxia, and endothelial dysfunction, coupled with differential exosomal release profiles with immune modulation effects. Hence, this study evaluated the impact of circulating exosomes derived from early and late-onset pre-eclamptic pregnancies on inflammatory cytokine secretion by BeWo cells. Study Design: Exosomes were isolated from plasma obtained from early-onset pre-eclamptic (EOPE; n = 15), late-onset pre-eclamptic (LOPE; n = 15), and gestational age-matched normotensive pregnancies (N  33 weeks; n = 15 and N  34 weeks; n = 15). Human BeWo cells were treated with characterized and quantified exosomes (100 mg/mL exosomal protein per pregnant group) for 24 h. The immunoassay method was used to measure the concentration of IL-8, IL-10, leptin, and HIF-α. Results: Exosome administration from women with EOPE and LOPE increased IL-8 and decreased IL-10 expression in BeWo cells. Conclusion: Cumulatively, our data demonstrated that circulating exosomes from the placenta and activated immune cells potentially influence inflammatory cytokine production in pre-eclamptic pregnancies. © 2020 Elsevier B.V. All rights reserved. 1 Introduction A unique immunological phenomenon, known as “immune tolerance” occurs during pregnancy, allowing for productive coexistence of the semiallogeneic fetus in the uterus [1,2]. Although it requires several simultaneous mechanisms from the fetus and mother to protect the fetus from immunological recognition and rejection by the mother [1], the placenta vastly mediates the maternal adaptations. It is also the functional interface between the mother and fetus that secretes hormones and growth factors into the maternal circulation [3]. Besides, the placenta and immune cells release sub-cellular vesicles into the maternal circulation, which are actively involved in the maternal- fetal communication to elucidate potential mechanisms of immune modulation during gestation for successful fetus devel- opment [4–6]. For example, exosomes are released into the maternal circulation as early as seven weeks of pregnancy [4,7], and the concentration of exosomes in maternal plasma propor- tionally increases with gestational age. Unfortunately, exosomes are also associated with pregnancy complications such as diabetes mellitus, preterm birth, and pre-eclampsia (PE) [8–11]. Pre-eclampsia is a disorder with the presence of elevated blood pressure (140/90 mmHg) and proteinuria occurring after 20 weeks of gestation in a previously normotensive patient [12, 13]. Its pathophysiology is not fully understood. However, placental hypoxia, oxidative stress, and endothelial dysfunction are critical events that result in the clinical manifestation of PE [12–14]. Furthermore, a healthy pregnancy is considered as a Th2 type immunological state, and pre-eclamptic pregnancy, a maternal pro-inflammatory state with Th1 predominance [15]. Due to this imbalance between pro-inflammatory cytokines (i.e. IL-1, IL-6, IL- 8, IL-17, and TNF-α) and anti-inflammatory regulatory interleukins (i.e. IL-10, IL-33, and IL-35), inflammation is regarded as a critical mediator of PE [12, 16]. It is worth noting that the concentration of exosomes in PE patients are higher with altered molecular cargo than healthy pregnancies. Furthermore, women with early-onset PE (EOPE) * Corresponding author at: University of KwaZulu-Natal, School of Laboratory Medicine and Medical Sciences, Westville Campus, Durban, 3629, South Africa. E-mail address: madurayk@yahoo.com (K. Maduray). https://doi.org/10.1016/j.ejogrb.2020.02.032 0301-2115/© 2020 Elsevier B.V. All rights reserved. European Journal of Obstetrics & Gynecology and Reproductive Biology 247 (2020) 156–162 Contents lists available at ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology journal homepage: www.else vie r.com/locat e/e jogrb