Maternal serum activin A is not elevated before preeclampsia in women who are at high risk

Impact of HIV-1 infection on the IGF-1 axis and angiogenic factors in pregnant Cameroonian women receiving antiretroviral therapy

Although mother-to-child transmission of HIV has dramatically declined, the number of in utero HIV-exposed, uninfected infants is on the increase. HIV-exposed infants are at an increased risk of mortality, morbidity and slower early growth than their non-HIV exposed counterparts. Maternal HIV increases the risk of having preterm deliveries, intrauterine growth restriction and low birth weight babies. However, the mechanism underlying dysregulation of fetal growth in HIV-infected pregnant women is unknown. We sought to determine whether maternal HIV is associated with dysregulation of the insulin-like growth factor (IGF) axis, some angiogenic factors or other related biomarkers that regulate fetal growth. A total of 102 normotensive pregnant women were enrolled in a small cross-sectional study. Amongst these were thirty-one HIV-1 positive women receiving combination antiretroviral therapy (cART) (Mean age: 30.0 ± 5.1 years; % on ART: 83.9%; median plasma viral load: 683 copies/ml; median CD4 count: 350 cells/ul) and 71 HIV uninfected women (mean age: 27.3 ± 5.8) recruited at delivery. A panel of biomarkers including IGF1 and IGF binding proteins (IGFBP1, IGFBP3), angiopoietins (ANG) 1 and 2, matrix metalloproteinases (MMP) 2 and 9, and galectin 13, was measured in plasma collected from the placental intervillous space. The levels of IGF1, IGFBP1, ANG1, ANG2, MMP2, MMP9 and Gal-13 were not affected by maternal HIV, even when adjusted for maternal factors in linear regression models (all p>0.05). It was observed that HIV-infection in pregnancy did not significantly affect key markers of the IGF axis and angiogenic factors. If anything, it did not affect women. These findings highlight the importance of the use of ART during pregnancy, which maintains factors necessary for fetal development closer to those of healthy women. However, decrease in IGF1 levels might be exacerbated in women con-infected with HIV and malaria.

The possible role of extravillous trophoblast-derived exosomes on the uterine spiral arterial remodeling under both normal and pathological conditions

A tenet of contemporary obstetrics is that events that compromise placentation increase the risk of complications of pregnancy and contribute to poor pregnancy outcome. In particular, conditions that affect the invasion of placental cells and remodeling of uterine spiral arteries compromise placental function and the subsequent development of the fetus. Extravillous trophoblast cells (EVTs) proliferate and migrate from the cytotrophoblast in the anchoring villi of the placenta and invade the maternal decidua and myometrium. These cells are localised with uterine uterine spiral arteries and are thought to induce vascular remodeling. A newly identified pathway by which EVTs may regulate vascular remodeling within the uterus is via the release of exosomes. Trophoblast cells release exosomes that mediate aspects of cell-to-cell communication. The aim of this brief commentary is to review the putative role of exosomes released from extravillous trophoblast cells in uterine spiral artery remodeling and, in particular, their role in the aetiology of preeclampsia. Placental exosomes may engage in local cell-to-cell communication between the cell constituents of the placenta and contiguous maternal tissues and/or distal interactions, involving the release of placental exosomes into biological fluids and their transport to a remote site of action.

Extravillous trophoblast cells-derived exosomes promote vascular smooth muscle cell migration

Background: Vascular smooth muscle cells (VSMCs) migration is a critical process during human uterine spiral artery (SpA) remodeling and a successful pregnancy. Extravillous trophoblast cells (EVT) interact with VSMC and enhance their migration, however, the mechanisms by which EVT remodel SpA remain to be fully elucidated. We hypothesize that exosomes released from EVT promote VSMC migration.

Methods: JEG-3 and HTR-8/SVneo cell lines were used as models for EVT. Cells were cultured at 37°C and humidified under an atmosphere of 5% CO₂-balanced N₂ to obtain 8% O₂. Cell-conditioned media were collected, and exosomes (exo-JEG-3 and exo- HTR-8/SVneo) isolated by differential and buoyant density centrifugation. The effects of exo-EVT on VSMC migration were established using a real-time, live-cell imaging system (Incucyte™). Exosomal proteins where identified by mass spectrometry and submitted to bioinformatic pathway analysis (Ingenuity software).

Results: HTR-8/SVneo cells were significantly more (~30%) invasive than JEG-3 cells. HTR-8/SVneo cells released 2.6-fold more exosomes (6.39 × 10⁸ ± 2.5 × 10⁸ particles/10⁶ cells) compared to JEG-3 (2.86 × 10⁸ ± 0.78 × 10⁸ particles/10⁶ cells). VSMC migration was significantly increased in the presence of exo-JEG-3 and exo-HTR-8/SVneo compared to control (−exosomes) (21.83 ± 0.49 h and 15.57 ± 0.32, respectively, vs. control 25.09 ± 0.58 h, p < 0.05). Sonication completely abolished the effect of exosomes on VSMC migration. Finally, mass spectrometry analysis identified unique exosomal proteins for each EVT cell line-derived exosomes.

Conclusion: The data obtained in this study are consistent with the hypothesis that the release, content, and bioactivity of exosomes derived from EVT-like cell lines is cell origin-dependent and differentially regulates VSMC migration. Thus, an EVT exosomal signaling pathway may contribute to SpA remodeling by promoting the migration of VSMC out of the vessel walls.

World Health Organization Systematic Review of Screening Tests for Preeclampsia

OBJECTIVE

We sought to assess the usefulness of clinical, biophysical, and biochemical tests in the prediction of preeclampsia.

DATA SOURCES

The sources of data we used to conduct this review included the computerized databases MEDLINE (1966 to February 2003), EMBASE, Popline, CINAHL, and LILACS plus reference lists, conference proceedings, textbooks, and contact with experts.

METHODS OF STUDY SELECTION

All cohort or cross-sectional studies reporting data on the relationship between a predictive test that was performed during pregnancy and the development of preeclampsia were eligible for inclusion, whereas case-control studies were excluded. Eighty-seven (211,369 women) of 7,191 potentially relevant articles met inclusion criteria. We evaluated the methodologic quality for each included study.

TABULATION, INTEGRATION, AND RESULTS

Using a standardized protocol, one reviewer selected and extracted data on study characteristics, quality, and accuracy. Data abstracted from each study were arranged in 2 x 2 tables to construct receiver operating characteristics plots (sensitivity against 1 - specificity) and pooled to produce summary likelihood ratios for positive and negative tests results. Moderate predictive accuracy of anticardiolipin antibodies, the presence of bilateral diastolic notches during Doppler ultrasonography, and urinary kallikrein were found in women at low risk of developing preeclampsia. Nevertheless, because the pretest probability of preeclampsia with a positive result was but minimally increased, the clinical use of these tests is limited. Other ultrasonography characteristics and the measurement of fetal and placental peptides showed low predictive accuracy. In populations that were deemed at high risk for preeclampsia, the use of Doppler ultrasonography had low predictive accuracy. No definitive conclusions were possible in the case of many other tests, because the number of studies that met the minimal inclusion criteria was limited.

CONCLUSION

As of 2004, there is no clinically useful screening test to predict the development of preeclampsia. Further prospective, longitudinal studies are needed.

Inhibins and activins in pregnancy

Human placenta, decidua, and fetal membranes are the major sites of production and secretion of inhibin A and activin A in maternal serum, amniotic fluid, and umbilical cord blood. These tissues also express follistatin-related gene and betaglycan, the binding proteins of activin A and inhibin A, respectively, recently identified. They show a different expression throughout pregnancy, suggesting new functional roles into gestational tissues. The availability of suitable assays for measuring inhibin A and activin A lead us the possibility to investigate their secretion in healthy pregnancy. In addition, several evidences underline the potential role and the clinical usefulness of their measurement in the diagnosis, prevention, prognosis and follow-up of different gestational pathologies such as: threatened abortion, placental tumors, hypertensive disorders of pregnancy, intrauterine growth restriction, fetal hypoxia. The measurement of inhibin A and activin A into the biological fluids of pregnancy will offer in the future further possibilities in early diagnosis, prediction, and monitoring pregnancy diseases.