Adverse effects of perinatal nicotine exposure on reproductive outcomes

Nicotine exposure during pregnancy through cigarette smoking, nicotine replacement therapies or e-cigarette use continues to be a widespread public health problem, impacting both fetal and postnatal health. Yet, at this time, there remains limited data regarding the safety and efficacy in using these nicotine products during pregnancy. Notably, reports assessing the effect of nicotine exposure on postnatal health outcomes in humans, including reproductive health, are severely lacking. Our current understanding regarding the consequences of nicotine exposure during pregnancy is limited to a few animal studies, which do not comprehensively address the underlying cellular mechanisms involved. This paper aims to critically review the current knowledge from human and animal studies regarding the direct and indirect effects (e.g. obesity) of maternal nicotine exposure, regardless of its source, on reproductive outcomes in pregnancy and postnatal life. Furthermore, this review highlights several key cellular mechanisms involved in these adverse reproductive deficits including oxidative stress, inflammation, and endoplasmic reticulum (ER) stress. By understanding the interplay of the cellular mechanisms involved, further strategies could be developed to prevent the reproductive abnormalities resulting from exposure to nicotine in utero and influence informed clinical guidelines for pregnant women

Evidence-Based View of Safety and Effectiveness of Prokineticin Receptors Antagonists during Pregnancy

Endocrine gland derived vascular endothelial growth factor (EG-VEGF) is a canonical member of the prokineticin (PROKs) family. It acts via the two G-protein coupled receptors, namely PROKR1 and PROKR2. We have recently demonstrated that EG-VEGF is highly expressed in the human placenta; contributes to placental vascularization and growth and that its aberrant expression is associated with pregnancy pathologies including preeclampsia and fetal growth restriction. These findings strongly suggested that antagonization of its receptors may constitute a potential therapy for the pregnancy pathologies. Two specific antagonists of PROKR1 (PC7) and for PROKR2 (PKRA) were reported to reverse PROKs adverse effects in other systems. In the view of using these antagonists to treat pregnancy pathologies, a proof of concept study was designed to determine the biological significances of PC7 and PKRA in normal pregnancy outcome. PC7 and PKRA were tested independently or in combination in trophoblast cells and during early gestation in the gravid mouse. Both independent and combined treatments uncovered endogenous functions of EG-VEGF. The independent use of antagonists distinctively identified PROKR1 and PROKR2-mediated EG-VEGF signaling on trophoblast differentiation and invasion; thereby enhancing feto-placental growth and pregnancy outcome. Thus, our study provides evidence for the potential safe use of PC7 or PKRA to improve pregnancy outcome

Prion protein expression and functional importance in developmental angiogenesis: role in oxidative stress and copper homeostasis.

International audienceAIM: It has been convincingly shown that oxidative stress and toxicity by deregulated metals, such as copper (Cu), are tightly linked to the development of pre-eclampsia and intrauterine growth retardation (IUGR), the most threatening pathologies of human pregnancy. However, mechanisms implemented to control these effects are far from being understood. Among proteins that bind Cu and insure cellular protection against oxidative stress is the cellular prion protein (PrP(C)), a glycosyl phosphatidyl inositol-anchored glycoprotein, which we reported to be highly expressed in human placenta. Herein, we investigated the pathophysiological role of PrP(C) in Cu and oxidative stress homeostasis in vitro using human placenta and trophoblast cells, and in vivo using three strains of mice (C57Bl6, PrP(C) knockout mice [PrP(-/-)], and PrP(C) overexpressing mice [Tga20]). RESULTS: At the cellular level, PrP(C) protection against oxidative stress was established in multiple angiogenic processes: proliferation, migration, and tube-like organization. For the animal models, lack (PrP(-/-)) or overexpression (Tga20) of PrP(C) in gravid mice caused severe IUGR that was correlated with a decrease in litter size, changes in Cu homeostasis, increase in oxidative stress response, development of hypoxic environment, failure in placental function, and maintenance of growth defects of the offspring even 7.5 months after delivery. INNOVATION: PrP(C) could serve as a marker for the idiopathic IUGR disease. CONCLUSION: These findings demonstrate the stress-protective role of PrP(C) during development, and propose PrP(C) dysregulation as a novel causative element of IUGR

Prokineticin1 and pregnancy

International audienceProkineticin 1 (PROK1), also called EG-VEGF, is a peptide of 86 amino acids with multiple biological functions. PROK1 acts via two G-protein coupled receptors: PROKR1 PROKR2. PROK1 is highly expressed in the placenta. This article reports the expression and the role of PROK1 during normal and pathological pregnancies: (i) during early pregnancy, PROK1 exhibits a peak of placental expression shortly before the establishment of the feto-maternal circulation; (ii) its receptors, PROKR1 PROKR2 are highly expressed in human placenta; (iii) its expression is increased by hypoxia; (iv) PROK1 inhibits extravillous trophoblasts migration and invasion and increases their proliferation and survival; (v) PROK1 is also a pro-angiogenic placental factor that increases microvascular placental endothelial cells proliferation, migration, invasion, and permeability. Circulating PROK1 levels are five times higher in pregnant women during the first trimester compared to the second and third trimesters. Also, its serum levels are higher in patients with preeclampsia (PE) and in patients with isolated intra-uterine growth restriction (IUGR). In mice, maintaining high level of PROK1 beyond its normal period of production (>10.5dpc) reproduces symptoms of PE. To date, our results demonstrated that PROK1 is a central factor of human placentation with direct roles both in the control of trophoblast invasion and villous growth. Thus, a failure in the expression of PROK1 and/or its receptor during pregnancy may contribute to the development of PE and/or IUGR. Besides theses original findings, we also report a direct role of this factor in parturition

Normal and Pathological Placental Angiogenesis

International audiencePlacental angiogenesis is a pivotal process that establishes fetomaternal circulation, ensures efficient maternofetal exchanges, plays a key mechanistic role in the elaboration of the placental villous tree, and contributes to the overall development of the placenta throughout pregnancy. Failure in these processes is tightly linked to the development of placental pathologies such as preeclampsia (PE), early pregnancy loss, and intrauterine growth restriction (IUGR). It is now well established that a close relationship exists between embryonic development and the degree of placental angiogenesis. A key discovery in the investigation of placental pathologies was the understanding that major phenotypes of PE are associated with dysregulation in angiogenic factors. During the last decade multiple new key angiogenic proteins have been reported to play crucial roles in placental angiogenesis; these include netrins, EG-VEGF (endocrine gland derived endothelial growth factor), and angiogenin. Furthermore, placental angiogenesis appears to also be regulated by specific microRNAs (miRNAs), deregulations of which have also been shown to be associated with pregnancy pathologies. By affecting placental angiogenesis, numerous insults have been shown to influence pregnancy outcomes. These include (i) oxidative stress, (ii) hyperglycemia, and (iii) failure in immune system adaptations to pregnancy, such as the presence of antiphospholipid antibodies (aPL) and/or soluble Mic (sMIC). In the present scope authors reported new findings in the field of placental angiogenesis, discussed the advancements made in the diagnosis of pathologies reported to be associated with placental angiogenesis, and brought new insights into the processes of vasculogenesis and angiogenesis occurring throughout pregnancy in the placenta. More importantly, regulators of the key protagonists of vascular and angiogenic processes have been reported and their roles discussed. The reviews by M. Dakouane-Giudicelli et al., N. Pavlov et al., and N. Alfaidy et al. reported the role of three newly discovered angiogenic placental factors, netrin-1 and netrin-4, angiogenin, and EG-VEGF, respectively. M. Dakouane-Giudicelli et al. highlighted the opposite role that netrin-1 and netrin-4 might play in normal and pathological pregnancies. Netrin-1 and netrin-4 have been found to be either proangio-genic or antiangiogenic factors in the human placenta. These opposite effects appear to be related to the endothelial cell phenotype studied and seem also to depend on the type of receptor to which each netrin binds. N. Pavlov et al. demonstrated that the proangiogenic protein, angiogenin, might play a key role in placental blood vessel formation as well as in the cross talk between trophoblasts and endothelial cells. The review by N. Alfaidy et al. recapitulates EG-VEGF mediated-angiogenesis within the placenta and at the fetomaternal interface and proposes that its deregulation might contribute to the pathogenesis of several placental pathologies including IUGR and PE. More importantly, this article argues for EG-VEGF clinical relevance as a potential biomarker of the onset of pregnancy pathologies and discusses its potential usefulness for future therapeutic directions. In a second set of reviews of the scope Dr. R. D. Pereira et al. reported the effect of oxidative stress on the expression of a number of transcription factors that are important in mediating angiogenesis and stressed that the understanding of how oxidative stress affects redox-sensitive transcriptio

Expression of Matrix Metalloproteinase (MMP)-2 and MMP-9 in Human Placenta and Fetal Membranes in Relation to Preterm and Term Labor

International audienceExtensive extracellular matrix (ECM) remodeling is found in many processes during human parturition at term and preterm. These include cervical ripening, fetal membrane rupture, and placental detachment from the maternal uterus. Matrix metalloproteinases (MMPs) are the main mediators of ECM degradation. The present study was designed to investigate the expression of MMP-2 and MMP-9 in human fetal membranes (FMs) and placental (PL) tissues with or without labor at preterm and term parturition. Both zymography and Western blot analysis showed that MMP-9 was significantly (P < 0.01) increased in preterm and term labor FM, compared with nonlabor. Term labor PL also had a much higher (P < 0.05) level of MMP-9 than that of term nonlabor. No significant difference in MMP-2 expression was found between labor and nonlabor tissues. Immunolocalization studies revealed a specific distribution pattern for MMP-2 and MMP-9. MMP-2 was localized to the amnion mesenchyme, chorion laeve trophoblast, decidua parietalis, and blood vessels in PL villi. MMP-9 was localized mainly to amnion epithelia, chorion laeve trophoblast, decidua parietalis, and PL syncytiotrophoblasts. Separate cell culture from different layers of FM and culture of purified PL trophoblast cells showed that PL syncytiotrophoblast and amnion epithelial cells exclusively produced MMP-9; chorion trophoblast cells secreted both MMP-2 and MMP-9, but amnion mesenchymal cells produced only MMP-2. We concluded that MMP-2 and MMP-9 exhibited cell-specific expression in the human PL. An increase in MMP-9 expression may contribute to degradation of the ECM in the FM and PL, thereby facilitating FM rupture and PL detachment from the maternal uterus at labor, both preterm and term

Placental expression of EG-VEGF and its receptors PKR1 (prokineticin receptor-1) and PKR2 throughout mouse gestation.

International audienceCompelling evidence indicates that vascular endothelial growth factor (VEGF) is an important mediator of placental angiogenesis and appears to be disregulated in pre-eclampsia (PE). Recently, we characterised the expression of EG-VEGF (endocrine gland-derived vascular endothelial growth factor), also known as prokineticin 1 (PK1) in human placenta during the first trimester of pregnancy and showed that this factor is likely to play an important role in human placentation. However, because it is impossible to prospectively study placentation in humans, it has been impossible to further characterise EG-VEGF expression throughout complete gestation and especially at critical gestational ages for PE development. In the present study, we used mouse placenta to further characterise EG-VEGF expression throughout gestation. We investigated the pattern of expression of EG-VEGF and its receptors, PKR1 and PKR2 at the mRNA and protein levels. Our results show that EG-VEGF and VEGF exhibit different patterns of expression and different localisations in the mouse placenta. EG-VEGF was mainly localised in the labyrinth whereas VEGF was mainly present in glycogen and giant cells. EG-VEGF mRNA and protein levels were highest before 10.5days post coitus (dpc) whereas those of VEGF showed stable expression throughout gestation. PKR1 protein was localised to the labyrinth layer and showed the same pattern of expression as EG-VEGF whereas PKR2 expression was maintained over 10.5dpc with both trophoblastic and endothelial cell localisations. Altogether these findings suggest that EG-VEGF may have a direct effect on both endothelial and trophoblastic cells and is likely to play an important role in mouse placentation

Expression and oxygen regulation of endocrine gland-derived vascular endothelial growth factor/prokineticin-1 and its receptors in human placenta during early pregnancy.

International audienceAngiogenesis is a key process of dynamic tissue remodeling occurring during placentation. Compelling evidence indicates that vascular endothelial growth factor (VEGF) is an important mediator of placental angiogenesis and appears to be deregulated in preeclampsia. Recently a new angiogenic factor, endocrine gland-derived VEGF (EG-VEGF), also known as prokineticin 1 (PK1), has been identified, and its expression was shown to be restricted to endocrine glands, including the placenta. In this study we investigated the pattern of expression of EG-VEGF, its related factor Bv8/PK2, and their common receptors, PKR1 and PKR2, in human placenta during the first trimester of pregnancy. We also examined EG-VEGF and PKR1 regulation by oxygen tension in isolated trophoblast cells (TCs). Our results show that EG-VEGF, but not Bv8/PK2, is expressed in human placenta. EG-VEGF is mainly localized to the syncytiotrophoblast layer with the highest expression detected between the 8th and 10th wk of gestation. EG-VEGF expression within placental villi is different from that of VEGF, which is mainly localized in the cytotrophoblast and extravillous trophoblast cells. In TCs, PKR1 mRNA is about 80 times more abundant than PKR2 mRNA. Both EG-VEGF and PKR1 mRNAs appear to be regulated by hypoxia. These findings suggest that EG-VEGF has a direct effect on TCs via its receptor PKR1 and is likely to play an important role in human placentation. The expression pattern of EG-VEGF, its regulation by oxygen tension, and its complementary localization to that of VEGF suggest that this new factor might also be deregulated in preeclampsia

Expression of extracellular matrix metalloproteinase inducer in human placenta and fetal membranes at term labor

International audienceMatrix metalloproteinases (MMPs) are the main mediators of extracellular matrix (ECM) degradation during human parturition. However, the mechanisms involved in regulation of MMP production during parturition remain poorly understood. Recently, an extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to play a key role, as a local regulator, in stimulating MMP production in cancer systems. Whether EMMPRIN is expressed and stimulates MMP production in human placenta and fetal membranes is presently unknown. In this study, we investigated the expression of EMMPRIN at the levels of mRNA and protein in human term placenta and fetal membranes with or without labor. Western blot analysis showed that EMMPRIN protein was detected in term placenta and fetal membranes at two molecular masses of 40 and 65 kDa (glycosylated protein) and one of approximately 30 kDa (nonglycosylated protein). The ratio of 65 kDa EMMPRIN to total EMMPRIN significantly increased (P < 0.05) in term labor chorio-decidua and amnion compared with nonlabor chorio-decidua and amnion. Immunohistochemical analysis revealed that EMMPRIN was expressed in placental syncytiotrophoblast, amniotic epithelial cells, trophoblast cells of chorion laeve, and decidua parietalis. EMMPRIN was also detected at the mRNA level using RT-PCR in cultured placental syncytiotrophoblast, amniotic epithelial cells, and chorionic trophoblast cells. We conclude that human placenta and fetal membranes express EMMPRIN, with the potential to stimulate MMP production, thereby facilitating fetal membrane rupture and leading to detachment of the placenta and fetal membranes from the maternal uterus at the time of parturition

Effects of Dexamethasone and Sulfasalazine on Prostaglandin E2 Output by Human Placental Cells In Vitro

International audienceProstaglandins (PG) are key mediators of the labor process. We investigated effects of dexamethasone on PGE2 output in term human placental cells in the presence of indomethacin, an inhibitor of PGH synthase enzymes PGHS1 and PGHS2 activity; meloxicam, a relatively specific inhibitor of PGHS2; and sulfasalazine, an inhibitor of 15-OH PG dehydrogenase (PGDH), a PG-metabolizing enzyme