Fetuses from preeclamptic mothers show reduced hepatic erythropoiesis

Placental cell conditioned media modifies hematopoietic stem cell transcriptome invitro

INTRODUCTION

Hematopoietic stem cells are cells that differentiate into blood cell types. Although the placenta secretes hormones, proteins and other factors important for maternal/fetal health, cross-talk between placental and hematopoietic stem cells is poorly understood. Moreover, toxicant impacts on placental-hematopoietic stem cell communication is understudied. The goals of this study were to determine if factors secreted from placental cells alter transcriptomic responses in hematopoietic stem cells and if monoethylhexyl phthalate (MEHP), the bioactive metabolite of the pollutant diethylhexyl phthalate, modifies these effects.

METHODS

We used K-562 and BeWo cells as in vitro models of hematopoietic stem cells and placental syncytiotrophoblasts, respectively. We treated K-562 cells with medium conditioned by incubation with BeWo cells, medium conditioned with BeWo cells treated with 10 μM MEHP for 24 h, or controls treated with unconditioned medium. We extracted K-562 cell RNA, performed RNA sequencing, then conducted differential gene expression and pathway analysis.

RESULTS

Relative to controls, K-562 cells treated with BeWo cell conditioned medium differentially expressed 173 genes (FDR<0.05 and fold-change>2.0), including 2.4-fold upregulatation of tropomyosin 4 (TPM4, a cytoskeletal regulator involved in processes such as cell morphology and migration) and 3.3-fold upregulatation of sphingosine-1-phosphate receptor 3 (S1PR3, a mediator of myeloid cell differentiation and inflammatory responses). Upregulated genes were enriched for pathways including stem cell maintenance, cell proliferation and immune processes. Downregulated genes were enriched for terms involved in protein translation and transcriptional regulation. MEHP treatment differentially expressed eight genes (FDR<0.05), including genes involved in lipid metabolism (e.g., Perilipin 2, fold-change: 1.4; Carnitine Palmitoyltransferase 1A, fold-change: 1.4).

DISCUSSION

K-562 cells, a model of hematopoietic stem cells, are responsive to media conditioned by placental cells, potentially impacting pathways like stem cell maintenance.

Growth-Restricted Fetuses and Offspring Reveal Adverse Sex-Specific Metabolic Responses in Preeclamptic Mice Expressing Human sFLT1

Fetal adaptations to harmful intrauterine environments due to pregnancy disorders such as preeclampsia (PE) can negatively program the offspring's metabolism, resulting in long-term metabolic changes. PE is characterized by increased circulating levels of sFLT1, placental dysfunction and fetal growth restriction (FGR). Here we examine the consequences of systemic human sFLT1 overexpression in transgenic PE/FGR mice on the offspring's metabolic phenotype. Histological and molecular analyses of fetal and offspring livers as well as examinations of offspring serum hormones were performed. At 18.5 dpc, sFLT1 overexpression resulted in growth-restricted fetuses with a reduced liver weight, combined with reduced hepatic glycogen storage and histological signs of hemorrhages and hepatocyte apoptosis. This was further associated with altered gene expression of the molecules involved in fatty acid and glucose/glycogen metabolism. In most analyzed features males were more affected than females. The postnatal follow-up revealed an increased weight gain of male PE offspring, and increased serum levels of Insulin and Leptin. This was associated with changes in hepatic gene expression regulating fatty acid and glucose metabolism in male PE offspring. To conclude, our results indicate that sFLT1-related PE/FGR in mice leads to altered fetal liver development, which might result in an adverse metabolic pre-programming of the offspring, specifically targeting males. This could be linked to the known sex differences seen in PE pregnancies in human.

Placental Cell Conditioned Media Modifies Hematopoietic Stem Cell Transcriptome In Vitro

Background

Hematopoietic stem cells are cells that differentiate into all blood cell types. Although the placenta secretes hormones, proteins and other factors important for maternal and fetal health, cross-talk between placental cells and hematopoietic stem cells is poorly understood. Moreover, toxicant impacts on placental-hematopoietic stem cell communication is understudied. The goals of this study were to determine if factors secreted from placental cells alter transcriptomic responses in hematopoietic stem cells and if monoethylhexyl phthalate (MEHP), the bioactive metabolite of the pollutant diethylhexyl phthalate, modifies these effects.

Methods

We used K-562 and BeWo cells as in vitro models of hematopoietic stem cells and placental syncytiotrophoblasts, respectively. We treated K-562 cells with medium conditioned by incubation with BeWo cells, medium conditioned with BeWo cells treated with 10 μM MEHP for 24 hours, or controls treated with unconditioned medium. We extracted K-562 cell RNA, performed RNA sequencing, then conducted differential gene expression and pathway analysis by treatment group.

Results

Relative to controls, K-562 cells treated with BeWo cell conditioned medium differentially expressed 173 genes (FDR<0.05 and fold-change>2.0), including 2.4 fold upregulatation of TPM4 and 3.3 fold upregulatation of S1PR3. Upregulated genes were enriched for pathways including stem cell maintenance, cell proliferation and immune processes. Downregulated genes were enriched for terms involved in protein translation and transcriptional regulation. MEHP treatment differentially expressed eight genes (FDR<0.05), including genes involved in lipid metabolism (PLIN2, fold-change: 1.4; CPT1A, fold-change: 1.4).

Conclusion

K-562 cells, a model of hematopoietic stem cells, are responsive to media conditioned by placental cells, potentially impacting pathways like stem cell maintenance and proliferation.

The roles of free iron, heme, haemoglobin, and the scavenger proteins haemopexin and alpha-1-microglobulin in preeclampsia and fetal growth restriction

BACKGROUND

Preeclampsia (PE) is a complex pregnancy syndrome characterised by maternal hypertension and organ damage after 20 weeks of gestation and is associated with an increased risk of cardiovascular disease later in life. Extracellular haemoglobin (Hb) and its metabolites heme and iron are highly toxic molecules and several defence mechanisms have evolved to protect the tissue.

OBJECTIVES

We will discuss the roles of free iron, heme, Hb, and the scavenger proteins haemopexin and alpha-1-microglobulin in pregnancies complicated by PE and fetal growth restriction (FGR).

CONCLUSION

In PE, oxidative stress causes syncytiotrophoblast (STB) stress and increased shedding of placental STB-derived extracellular vesicles (STBEV). The level in maternal circulation correlates with the severity of hypertension and supports the involvement of STBEVs in causing maternal symptoms in PE. In PE and FGR, iron homeostasis is changed, and iron levels significantly correlate with the severity of the disease. The normal increase in plasma volume taking place during pregnancy is less for PE and FGR and therefore have a different impact on, for example, iron concentration, compared to normal pregnancy. Excess iron promotes ferroptosis is suggested to play a role in trophoblast stress and lipotoxicity. Non-erythroid α-globin regulates vasodilation through the endothelial nitric oxide synthase pathway, and hypoxia-induced α-globin expression in STBs in PE placentas is suggested to contribute to hypertension in PE. Underlying placental pathology in PE with and without FGR might be amplified by iron and heme overload causing oxidative stress and ferroptosis. As the placenta becomes stressed, the release of STBEVs increases and affects the maternal vasculature.

Reduced angiovasculogenic and increased inflammatory profiles of cord blood cells in severe but not mild preeclampsia

Preeclampsia (PE) is a prevalent pregnancy disorder that leads to high maternal and fetal morbidity and mortality. While defective vascular development and angiogenesis in placenta are known as crucial pathological findings, its pathophysiological mechanism remains elusive. To better understand the effects of PE on angio-vasculogenesis and inflammatory networks in the fetus and to identify their biological signatures, we investigated the quantitative and functional characteristics of cord blood-derived mononuclear cells (CB-MNCs) and CD31-positive MNCs. Flow cytometry analysis demonstrated that the CB-MNCs from the severe PE group had significantly decreased number of cells expressing CD3, CD11b, CD14, CD19, KDR, and CD31 compared with the normal group. Quantitative real time PCR (qRT-PCR) shows down-regulation of the major angiogenic factor VEGFA in MNCs and CD31⁺ MNCs in severe PE. The major inflammatory cytokines IL1 was highly upregulated in CD31⁺ CB-MNCs in the severe PE patients. Mild PE patients, however, did not display any significant difference in expression of all measured angiogenic genes and most inflammatory genes. These findings show distinct angiogenic and inflammatory signatures from severe PE, and they may play a significant role in the pathogenesis of vascular defects in placenta of severe PE.

Preeclampsia in pregnancy affecting the stemness and differentiation potency of haematopoietic stem cell of the umbilical cord blood

BACKGROUND

Umbilical cord blood (UCB) has been proposed as the potential source of haematopoietic stem cells (HSC) for allogeneic transplantation. However, few studies have shown that a common disease in pregnancy such as preeclampsia would affect the quality of UCB-HSC. Total nucleated cell count (TNC) is an important parameter that can be used to predict engraftment including UCB banking. Colony forming unit (CFU) assay is widely used as an indicator to predict the success of engraftment, since direct quantitative assay for HSC proliferation is unavailable. The aim of this study is to investigate the effects of preeclampsia in pregnancy on the stemness and differentiation potency of UCB-HSC.

METHODS

Mononuclear cells (MNC) were isolated from UCB and further enriched for CD34+ cells using immune-magnetic method followed by CFU assay. A panel of HSC markers including differentiated haematopoietic markers were used to confirm the differentiation ability of UCB-HSC by flow cytometry analysis.

RESULTS/ DISCUSSION

The HSC progenitor's colonies from the preeclampsia group were significantly lower compared to the control. This correlates with the low UCB volume, TNC and CD34+ cells count. In addition, the UCB-enriched CD34+ population were lymphoid progenitors and capable to differentiate into natural killer cells and T-lymphocytes.

CONCLUSION

These findings should be taken into consideration when selecting UCB from preeclamptic mothers for banking and predicting successful treatment related to UCB transplant.

Fetal programming of gene expression in growth-restricted rats depends on the cause of low birth weight

Low birth weight and intrauterine growth restriction (IUGR) can be caused by numerous different conditions. In many experimental settings, however, these different causes are not accounted for. This study aimed at comparing the impact of two frequent causes of IUGR (low utero-placental blood flow vs. malnutrition) on fetal programming of gene expression. We studied offspring of dams treated by uterine artery ligation or sham operation compared with untreated controls and offspring of dams that were fed either a low protein or normal protein diet. After Cesarean section at term, placental and fetal hepatic expression of key "metabolic" and "vasoregulative" genes was investigated by quantitative RT-PCR. Ligation neonates showed IUGR, reduced expression of placental leptin, placental and hepatic IGF-I, hepatic inducible nitric oxide synthase, and increased expression of placental IGF binding protein 1, hepatic IGF-II receptor and erythropoietin (EPO). Low protein offspring also showed IUGR but increased expression of placental leptin; IGF-I; placental and hepatic inducible nitric oxide synthase; hepatic insulin, IGF-I, and IGF-II receptors; and reduced expression of placental IGF binding protein 1, IGF-II, leptin-receptor type A, placental and hepatic leptin receptor type B, and EPO. Expression was independent of sex, birth weight, fetal intrauterine position, and EPO expression. In conclusion, the impact of IUGR on fetal and placental gene expression depends on the cause of low birth weight. Therefore, morbidity after IUGR should be analyzed referring to its pathophysiological cause rather than referring to low birth weight itself. Fetal hypoxia as estimated by hepatic EPO expression does not seem to be a key regulator of transcriptional activity in our models.

Tumor- and organ-dependent infiltration by myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSCs) increase during tumor growth and following cytoreductive therapy resulting in immune dysfunction and tumor escape from host control. We report organ- and tumor-specific expansion of MDSCs, differences in their molecular and membrane phenotypes and T-cell suppressive activity. A significant increase in MDSCs was observed within the spleen, peripheral blood (PB), bone marrow (BM), lungs, and livers of mice bearing orthotopic 4T1, but not CI66 mammary tumors. The PB of 4T1 TB mice had the highest frequency of MDSCs (78.6±2.1%). Similarly, the non-parenchymal cells (NPCs) in the tumor tissue, livers and lungs of 4T1 tumor-bearing (TB) mice had an increased MDSCs frequency. Studies into Gr-1 and Ly-6C staining of MDSCs revealed significant increases in CD11b+Gr-1(dull)Ly-6C(high) and CD11b+Gr-1(bright)Ly-6C(low) subsets. The frequency of MDSCs inversely correlated with the CD3+ T-cell frequency in the spleen, and blood of 4T1 TB mice and was associated with a significant decrease in splenic and NPCs IFN-γ and IL-12 transcript levels, as well as significantly increased levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), stem cell factor (SCF), granulocyte colony-stimulating factor (G-CSF), interleukin-10 (IL-10), interleukin-13 (IL-13), arginase-1 (ARG-1), nitric oxide synthase (NOS-2), vascular endothelial growth factor-A (VEGF-A) transcripts. In summary, MDSCs are significantly increased not only in lymphoid organs, but also in parenchymal organs including lungs and livers of TB mice, where they may facilitate metastasis to these organ sites.

17-Hydroxyprogesterone in premature infants as a marker of intrauterine stress

AIMS

Amniotic infection (AI) and preeclampsia (PE), which are commonly the reason for prematurity, inflict stress of different duration on immature fetuses. Whether chronic stress, as reflected by intrauterine growth retardation, influences the level of 17-OH progesterone (17-OHP), was not previously examined.

METHODS

We analyzed 17-OHP and TSH levels during neonatal screenings in the first hours of life of 90 premature infants born between 25 and 33 weeks of gestation in infants with AI (n=37) or with PE (n=53). Control of acute stress parameters was derived from umbilical arterial cord blood pH and base excess (BE).

RESULTS

Mean 17-OHP levels of infants born to mothers with PE were 85.7 nmol/L compared to 54.6 nmol/L (P<0.001) in AI infants. 17-OHP was even higher when intrauterine growth restriction was present (99.8 nmol/L). Antenatal steroids and mode of delivery did not significantly affect 17-OHP levels.

CONCLUSIONS

Stress of relatively long duration, as in cases of PE, leads to a significant increase of 17-OHP level in preterm infants. The postnatal 17-OHP level may be considered as a measure for severity of intrauterine stress and might be used as an individualized indicator for earlier intensive care.

Erythropoietin concentration among patients with and without preeclampsia

PURPOSE

Controversy exists in the literature regarding the association between erythropoietin levels and preeclampsia. This study was aimed to compare serum erythropoietin concentrations among patients with and without preeclampsia.

MATERIAL AND METHODS

A prospective study was designed and two groups were defined: 22 patients with preeclampsia (study group) and 19 normotensive patients (control group). Preeclampsia was defined as blood pressure higher than 140 mmHg systolic or 90 mmHg diastolic and proteinuria > 300/24 h or dipstick > 1. Women in the control group were matched for gestational age. Blood was collected in tubes containing EDTA, and centrifuged in 4 degrees C within 30 min of collection. Serum erythropoietin level was determined by ELISA (R&D Systems, Inc. Minneapolis, USA). Statistical analysis was performed using the SPSS package.

RESULTS

Erythropoietin concentration was higher among patients with preeclampsia, but did not reach significance (24.8 +/- 8.9 mU/ml vs. 19.9 +/- 9.9 mU/ml; P-0.19). Also, hemoglobin and hematocrit levels were similar in both groups (12.0 +/- 4.2 g/dl vs. 11.6 +/- 3.9 g/dl; P-0.16 and 36.5 +/- 10.8% vs. 35.3 +/- 11.4%; P-0.13, respectively).

CONCLUSIONS

A nonsignificant trend towards higher maternal serum levels of erythropoietin was demonstrated among patients with preeclampsia. Further prospective studies are needed to investigate the association between preeclampsia and erythropoietin.

The pulmonary paradox in premature infants: in-utero infected lungs do better than those with accelerated maturation

AIMS

To document, and explain, the pulmonary paradox whereby despite relative lung immaturity, preterm infants exposed to amniotic infection (AI) have better postnatal pulmonary function than those exposed to preeclampsia (PE).

METHODS

Lung maturation was characterized in 65 preterm perinatal deaths [AI (n=40) and PE (n=25)] and postnatal respiratory function in 100 preterm survivors [AI (n=50) and PE (n=50)].

RESULTS

At autopsy, lung architecture was in advance of gestational age in 5% of AI infants versus 40% of PE infants (P<0.001). In survivors, the groups were similar in age and Apgar scores. At birth, 40% of the AI group required continuous positive airway pressure or mechanical ventilation versus 24% of the PE group (NS). However, 24 hours later, only 1 AI infant had deteriorated compared to 40% of PE infants (P<0.05).

CONCLUSIONS

Accelerated morphologic lung maturation in preterm PE infants does not translate into improved postnatal respiratory function. Most likely, this is due to a relative lack of surfactant, ascribable to low stimulant cytokine and high TNF-alpha levels. An intrauterine history supplemented by an antenatal cytokine profile could identify an increased exogeneous surfactant need in preterm infants exposed to PE.

Effect of preeclampsia on umbilical cord blood hematopoietic progenitor-stem cells

OBJECTIVE

The aim of the present study was to determine the influence of preeclampsia on cord blood hematopoietic progenitor-stem cells obtained at delivery because cord blood is increasingly used clinically for stem cell retrieval as an alternative to bone marrow.

STUDY DESIGN

Umbilical cord blood was collected from patients fulfilling the criteria for preeclampsia and from gestational age- and birth weight-matched control subjects at delivery (patient/control subjects ratio, 1:2). Cord blood volume and nucleated cell content were measured, and the number of hematopoietic progenitor-stem cells was determined by means of fluorescence-activated cell sorting with the CD34(+) epitope and by means of colony assays with different hematopoietic growth factors. In addition, the expression of adhesion molecules by CD34(+) progenitor-stem cells was examined.

RESULTS

In pregnancies affected by preeclampsia, volume and nucleated cell and total CD34(+) cell contents in the collected cord blood were significantly smaller compared with those of control subjects. Furthermore, there was a trend toward a smaller relative number of CD34(+) cells and colony-forming units per nucleated cell in cord blood samples from preeclamptic patients. No difference in the expression of the cell-adhesion molecules leukocyte function-associated antigen 1, very late activation antigen 4, and L-selectin by CD34(+) cells could be found.

CONCLUSION

This study shows that preeclampsia affects umbilical cord blood volume and nucleated cell and progenitor-stem cell numbers obtained at birth.

Thrombopoietin in the thrombocytopenic term and preterm newborn

OBJECTIVES

Neonatal thrombocytopenia occurs commonly in neonatal intensive care units. The role of the thrombopoietin (Tpo) system in normal neonatal platelet regulation and neonatal thrombocytopenia is not well understood. The purpose of our study was to: 1) determine the normal Tpo level at birth in healthy nonthrombocytopenic term (NTT) and nonthrombocytopenic preterm (NTP) infants and in infants born to women with preeclampsia; and 2) measure Tpo levels in infants during and after the resolution of thrombocytopenia. Characterizing Tpo levels in the healthy and thrombocytopenic newborn is an important step in furthering our understanding of the pathophysiology of neonatal thrombocytopenia.

METHODS

This study is comprised of 2 parts. For the first part, cord blood was obtained at birth from both term (gestational age [GA]: 38-42 weeks) and preterm (GA: 25-36 weeks) infants. If birth platelet levels were >/=140 x 10(3)/microL and the infant fit criteria for being normal, or if the infant was born to a women with preeclampsia, Tpo levels were measured. For the second part, serial Tpo levels and concomitant platelet counts (Plts) were measured in both preterm and term infants during a period of marked thromboctyopenia (Plt < 100 x 10(3)/microL) until its resolution (Plt >/= 140 x 10(3)/microL).

RESULTS

Median cord blood Tpo levels from NTP infants (n = 35) were higher than those of NTT infants (n = 32; 95 pg/mL vs 48 pg/mL, respectively). In addition, preterm infants born to women with preeclampsia (n = 11) had lower Tpo levels than NTP infants with a similar GA (<41 pg/mL vs 95 pg/mL). For infants with marked thrombocytopenia, median Tpo levels during thrombocytopenia were similar between term (n = 12) and preterm (n = 14) groups (223 pg/mL and 179 pg/mL, respectively), with the majority of individuals showing a decrease in Tpo with resolution of thrombocytopenia. Within each group, there was large variability in the Tpo response to thrombocytopenia.

IMPRESSION

These data show that the Tpo system is intact in NTP and NTT neonates. Preeclampsia may be an example of a disorder that perturbs this system. The great variability in Tpo levels seen in infants during thrombocytopenia may be related to the mechanism of thrombocytopenia. The finding that, in general, Tpo levels decreased with resolution of thrombocytopenia is consistent with what has been described in adults and children.