Sex-biased regulatory changes in the placenta of native highlanders contribute to adaptive fetal development

Compared with lowlander migrants, native Tibetans have a higher reproductive success at high altitude though the underlying mechanism remains unclear. Here, we compared the transcriptome and histology of full-term placentas between native Tibetans and Han migrants. We found that the placental trophoblast shows the largest expression divergence between Tibetans and Han, and Tibetans show decreased immune response and endoplasmic reticulum stress. Remarkably, we detected a sex-biased expression divergence, where the male-infant placentas show a greater between-population difference than the female-infant placentas. The umbilical cord plays a key role in the sex-biased expression divergence, which is associated with the higher birth weight of the male newborns of Tibetans. We also identified adaptive histological changes in the male-infant placentas of Tibetans, including larger umbilical artery wall and umbilical artery intima and media, and fewer syncytial knots. These findings provide valuable insights into the sex-biased adaptation of human populations, with significant implications for medical and genetic studies of human reproduction.

Placental lesions and differential expression of pro-and anti-angiogenic growth mediators and oxidative DNA damage marker in placentae of Ghanaian suboptimal and optimal health status pregnant women who later developed preeclampsia

Background

Angiogenic growth mediators (AGMs) and oxidative stress (OS) both play essential roles in normal placental vascular development and as such, placental alterations in these factors contribute to pre-eclampsia (PE). Suboptimal health status (SHS), an intermediate between health and disease, has been associated with imbalanced AGMs and OS biomarkers. Thus, SHS pregnant women may be at increased risk of developing PE and may present abnormal placental alteration and expression of AGMs and OS compared to optimal health status (OHS) pregnant women. We examined the histopathological morphology, immunohistochemical expression of AGMs antibodies and oxidative DNA damage marker in the placentae of SHS and OHS pregnant women who developed early-onset PE (EO-PE) and late-onset (LO-PE) compared to normotensive pregnancy (NTN-P).

Methods

This nested case-control study recruited 593 singleton normotensive pregnant women at baseline (10–20 weeks gestation) from the Ghanaian Suboptimal Health Status Cohort Study (GHOACS) undertaken at the Komfo Anokye Teaching Hospital, Ghana. Socio-demographic, clinical and obstetrics data were collected, and a validated SHS questionnaire-25 (SHSQ-25) was used in classifying participants into SHS (n = 297) and OHS (n = 296). Participants were followed until the time of PE diagnosis and delivery (32–42 weeks gestation). Blood samples were collected at the two-time points and were assayed for AGMs; soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PIGF), vascular endothelial growth factor-A (VEGF-A), and soluble endoglin (sEng), and OS biomarkers; 8-hydroxydeoxyguanosine (8-OHdG), 8-epiprostaglandinF2-alpha (8- epi-PGF2α) and total antioxidant capacity (TAC) using ELISA. Placental samples were collected for histopathological and immunohistochemical analysis.

Results

Of the 593 pregnant women, 498 comprising 248 SHS and 250 OHS women returned for delivery and were included in the final analysis. Of the 248 SHS women, 56, 97 and 95 developed EO-PE, LO-PE and NTN-P, respectively, whereas 14, 30 and 206 of the 250 OHS mothers developed EO-PE, LO-PE and NTN-P, respectively. At baseline, SHS_NTN pregnant women had a significant imbalance in AGMs and OS biomarkers compared to OHS_NTN pregnant women (p<0.0001). At the time of PE diagnosis, SHS_NTN-P women who developed EO-PE, LO-PE, and NTN-P had lower serum levels of P1GF, VEGF-A and TAC and correspondingly higher levels of sEng, sFlt-1, 8-epiPGF2α, and 8-OHdG than OHS-NTN-P women who developed EO-PE and LO-PE, NTN-P (p<0.0001). A reduced placental size, increased foetal/placental weight ratio, and a significantly higher proportion of fibrinoid necrosis, infarction, villous fibrin, syncytial knots, calcification, chorangiosis, tunica media/vascular wall hypertrophy and chorioamnionitis was associated with the SHS group who developed PE (EO-PE>LO-PE) more than OHS groups who developed PE (EO-PE>LO-PE) when all were compared to NTN-P (p<0.0001). The intensity of antibody expression of PIGF and VEGF-A were significantly reduced, whereas Flt-1, Eng and 8-OHdG were significantly increased in placentae from SHS-pregnant women who developed EO-PE>LO-PE more than OHS- pregnant women who developed EO-PE>LO-PE when all were compared to NTN-P (p<0.0001).

Conclusion

Increased lesions, oxidative DNA damage, and imbalanced expression between pro-and anti-AGMs are associated more with SHS-embodied PE placentae rather than OHS-embodied PE subtypes, thus potentially allowing differential evaluation of PE.

Proteomic analysis of the umbilical cord in fetal growth restriction and preeclampsia

Fetal growth restriction (FGR) is associated with adverse perinatal outcomes. Pre-eclampsia (PreE) increases the associated perinatal morbidity and mortality. The structure of the umbilical cord in the setting of FGR and PreE is understudied. This study aimed to examine changes in the umbilical cord (UC) composition in pregnancies complicated by FGR and FGR with PreE. UC from gestational age-matched pregnancies with isolated FGR (n = 5), FGR+PreE (n = 5) and controls (n = 5) were collected, and a portion of the UC was processed for histologic and proteomic analysis. Manual segmentation analysis was performed to measure cross-section analysis of umbilical cord regions. Wharton’s Jelly samples were analyzed on a tims-TOF Pro. Spectral count and ion abundance data were analyzed, creating an intersection dataset from multiple mass spectrometry search and inference engines. UCs from FGR and FGR with PreE had lower cross-sectional area and Wharton’s Jelly area compared with control (p = 0.03). When comparing FGR to control, 28 proteins were significantly different in abundance analysis and 34 in spectral count analysis (p < 0.05). Differential expression analysis between PreE with FGR vs controls demonstrated that 48 proteins were significantly different in abundance and 5 in spectral count. The majority of changes occurred in proteins associated with extracellular matrix, cellular process, inflammatory, and angiogenesis pathways. The structure and composition of the UC is altered in pregnancies with FGR and FGR with PreE. Future work in validating these proteomic differences will enable identification of therapeutic targets for FGR and FGR with PreE.

Stereological and Histological Assessment of the Umbilical Cord in New-Born Rat

Background

Umbilical cord plays a crucial role in the continuation of pregnancy by transferring nutrition and oxygen across the placenta to the fetus. We aimed to investigate the morphometrical and histological features of the umbilical cords in new-born rats.

Materials and Methods

The adult male and female rats were chosen for matting purpose in the present study. Briefly, ten adult Wistar albino rats (female, n = 5; male, n = 5) were randomly assigned into five groups of two animals (female, n = 1; male, n = 1). Immediately after parturition, two umbilical cords of new-born rats (0-day-old) from each group were randomly selected. Finally, ten umbilical cord samples were examined using the histological and stereological methods in the light and electron microscopes.

Results

The total numbers of Hofbauer cells and mesenchymal stromal cells was estimated statistically. We also calculated the mean volume of umbilical cords, arteries and veins, as well as arterial and venous lumens. Our histological findings also exhibited the histological features of Hofbauer cells, mesenchymal stromal cell cells, and blood vessels.

Conclusion

Our findings showed more detailed information about umbilical cord tissues and their components, and that may contribute to the diagnose of umbilical cord complications in the developing fetus.

Twin gestation and the burden of adult cardio-renal disease

The rate of twin births has increased by nearly 80% in recent decades largely due to advanced reproductive technologies. Twins are often born preterm and/or growth restricted which are independently associated with impaired renal and vascular development. Many preterm and twin infants are surviving into adulthood, albeit with an increased burden of chronic health conditions. Twinning as a research tool offers the unique opportunity to investigate the impact of genetics versus the environment on clinical outcomes. This educational review will focus on delineating our current understanding of the renal and cardiovascular development and long-term outcomes among twin born individuals. Specifically, existing literature regarding how twins differ in kidney size and function as well as vascular stiffness and hypertension profiles from singletons will be discussed. The unique situation of twin-twin transfusion syndrome which is associated with distinct short- and long-term cardio-renal disease will be highlighted. Ultimately, the ability to stratify risk of future cardio-renal disease at birth for infants born preterm and/or growth restricted, including twins, is important to guide clinical follow up. In addition, this early risk stratification could direct research efforts to better understand the mechanisms driving impaired organogenesis and allow for discovery of therapeutic interventions aimed at modifying disease progression and improving longevity in the most vulnerable infant subgroups.

The histology and histomorphometry of umbilical cord cross section in preeclampsia and normal pregnancies: a comparative study

The umbilical cord is the connecting link between the mother and the fetus and its morphology is an indicator of fetal well-being. Preeclampsia is a disorder of pregnancy associated with new-onset hypertension, which occurs most often after 20 weeks of gestation. There are structural differences in the umbilical cord of normotensive and hypertensive pregnant women. This research aimed to study the histology and histomorphometry of umbilical cord areas in preeclampsia and compare the parameters with normal uncomplicated pregnancies of gestational age 37-40 weeks. A total of 70 umbilical cords were studied from preeclampsia (n = 35) and normal (n = 35) pregnancies. The parameters studied included cross-sectional areas (CSA) of umbilical cord, umbilical vein lumen, umbilical vein wall, umbilical artery lumen, umbilical artery wall, and Wharton's jelly, including the presence of edema in the vessel walls and Wharton's jelly and basement membrane thickening. The mean umbilical cord CSA was significantly higher in preeclampsia (p = 0.014). The mean umbilical artery lumen CSA was significantly lower than the normal pregnancy cords (p = 0.006). The mean Wharton's jelly CSA in preeclampsia was significantly higher than the normal pregnancy cords (p = 0.004). The parameters for umbilical vein lumen CSA, umbilical vein wall CSA, and umbilical artery wall CSA did not show any significant difference. Histological findings were edema (p < 0.001) and thickened basement membranes (p < 0.0001) were considered significant.

Association of Maternal and Umbilical Cord Blood Lipid Parameters with Uterine and Fetal-Placental Blood Flow in Hypertensive and Normotensive Pregnancies

Purpose

There is a growing evidence suggesting that hypertensive disorders of pregnancy (HDP), especially preeclampsia, are associated with an increased risk of cardiometabolic disease for both mother and child later in life. The objective of this study was to determine the association of maternal and umbilical cord blood (UCB) lipid profiles with uterine and fetal-placental blood flow at the third trimester of pregnancy.

Patients and Methods

A total of 1,135 women were prospectively followed through pregnancy and data for 812 mother-newborn pairs, including 170 HDP ‎developed subjects and ‎642 ‎normotensive subjects were analyzed at the end of the study. Maternal serum and UCB triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C levels were compared between HDP and normotensive groups; moreover, the association between lipid parameters and abnormal pulsatility indices (PIs) of uterine (UtA), umbilical (UA), and middle cerebral (MCA) arteries was evaluated with multivariate regression analysis models. The same analyses were carried out on subgroups of HDP (preeclampsia vs gestational hypertension).

Results

The mean TG, TC, LDL-C, and non-HDL-C levels were significantly higher in mother-newborn pairs of the HDP group compared to the normotensive group. In the HDP group, maternal TG and non-HDL-C levels were shown to have a significant association with abnormal UtA-PI (p<0.001 and p=0.039, respectively). We also found a positive significant association of fetal hypertriglyceridemia with abnormal UA-PI and MCA-PI in the HDP group (p=0.042 and p=0.021, respectively). However, no such associations were observed in normotensive mother-newborn pairs. Similar trends were observed in preeclamptic subjects after subgroup analysis.

Conclusion

Maternal TG and non-HDL-C levels as well as fetal TG level are significantly associated with disturbed uterine and fetal-placental blood flow in HDP.

Human umbilical cord and its vessels: a histomorphometric study in difference severity of hypertensive disorders of pregnancy

The umbilical cord (UC) is a platform for fetal nourishment and growth. The fetus, mother and placenta with UC form a triad, which contributes to pregnancy outcome. When pregnancy is complicated by a medical condition like hypertension, affects both maternal and fetal health. Being a fetal structure it can be used as a window to know the maternal dysfunctions and their impacts on fetal wellbeing. The present study is to explore the histomorphometric changes of the UC and its vessels involved in the development of hypertension during pregnancy. Sixty UCs were used and the following parameters, total UC area; total vessel area; jelly area; wall area, luminal area and wall thickness of umbilical arteries 1 and 2 and vein were studied using ImageJ software. From the results, the mean differences of above parameters of hypertensive UCs were found to be lesser than control and it was significantly higher in cases of severe preeclampsia (P≤0.05). From the present study, we conclude hypertensive cords and its vessels are associated with significant structural changes. Since it is a global health issue it is important to know the factors contributing it to diagnose and prevent.

Angiogenic capacity in pre-eclampsia and uncomplicated pregnancy estimated by assay of angiogenic proteins and an in vitro vasculogenesis/angiogenesis test

OBJECTIVE

The purpose of the study was to determine the angiogenic capacity of sera in early and late pregnancy and in umbilical blood serum after childbirth, and to define how angiogenic properties assessed in a functional in vitro test are related to individual angiogenic proteins in six women with pre-eclampsia and in six healthy pregnant controls.

METHODS

Maternal first and third trimester serum samples, and umbilical blood samples after childbirth, were tested in an in vitro human adipose stromal cell-human umbilical vein endothelial cell (hASC-HUVEC) vasculogenesis/angiogenesis assay. The angiogenic properties of the samples were measured by quantifying tubule formation. Concentrations of total placental growth factor (PlGF), total vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng) were determined by immunoassay.

RESULTS

First-trimester maternal sera of both groups had a stimulatory effect on angiogenesis in vitro and levels of angiogenic proteins did not differ between the groups. Third-trimester maternal sera in the pre-eclampsia group had an inhibitory effect on tubule formation, while those from normal pregnancies remained stimulatory. Compared with the first trimester there was a significant change in the concentrations of angiogenic proteins toward an anti-angiogenic state in pre-eclampsia. Umbilical blood serum exhibited strong anti-angiogenic effects without a significant difference between groups.

CONCLUSIONS

Third-trimester serum of pre-eclamptic patients is anti-angiogenic. This phenomenon is not yet present in the first trimester. Umbilical blood serum shows inhibitory effects on angiogenesis after normal as well as pre-eclamptic pregnancy.

Umbilical cord-derived mesenchymal stromal cells: predictive obstetric factors for cell proliferation and chondrogenic differentiation

Background

The umbilical cord is becoming a notable alternative to bone marrow (BM) as a source of mesenchymal stromal cells (MSC). Although age-dependent variations in BM-MSC are well described, less data are available for MSC isolated from Wharton’s jelly (WJ-MSC). We initiated a study to identify whether obstetric factors influenced MSC properties. We aimed to evaluate the correlation between a large number of obstetric factors collected during pregnancy and until peripartum (related to the mother, the labor and delivery, and the newborn) with WJ-MSC proliferation and chondrogenic differentiation parameters.

Methods

Correlations were made between 27 obstetric factors and 8 biological indicators including doubling time at passage (P)1 and P2, the percentage of proteoglycans and collagens, and the relative transcriptional expression of Sox-9, aggrecans, and total type 2 collagen (Coll2T).

Results

Amongst the obstetric factors considered, birth weight, the number of amenorrhea weeks, placental weight, normal pregnancy, and the absence of preeclampsia were identified as relevant factors for cell expansion, using multivariate linear regression analysis. Since all the above parameters are related to term, we concluded that WJ-MSC from healthy, full-term infants exhibit greater proliferation capacity. As for chondrogenesis, we also observed that obstetric factors influencing proliferation seemed beneficial, with no negative impact on MSC differentiation.

Conclusions

Awareness of obstetric factors influencing the proliferation and/or differentiation of WJ-MSC will make it possible to define criteria for collecting optimal umbilical cords with the aim of decreasing the variability of WJ-MSC batches produced for clinical use in cell and tissue engineering.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0609-z) contains supplementary material, which is available to authorized users.

Umbilical artery histomorphometry: a link between the intrauterine environment and kidney development

Prematurity is a risk factor for hypertension, vascular stiffness, nephron deficit and adult onset cardiorenal disease. The vascular tree and kidneys share morphogenic drivers that promote maturation in utero before 36 weeks of gestation. Vascular elastin accrual terminates after birth leaving collagen to promote vascular stiffness. Our objective was to determine if the histomorphometry of the umbilical artery, an extension of the aorta, parallels nephron mass across gestational age groups. From a cohort of 54 newborns, 32 umbilical cord specimens were adequate for evaluation. The umbilical cord was sectioned, stained with trichrome, and digitalized. Muscular and collagenous areas of the umbilical artery were measured in pixels using the Image J 1.48q software. Total kidney volume was measured by ultrasound and factored by body surface area (TKV/BSA). The umbilical artery total area was significantly greater in term v. preterm infants (9.3±1.3 v. 7.0±2.0 mm2; P<0.05) and increased with gestational age; while the percent muscular and collagen areas were independent of gestational age (R 2=0.04; P=ns). Percent muscular area correlated positively with TKV/BSA (r=0.53; P=0.002); while an increase in collagen correlated inversely with kidney mass (r=-0.53; P=0.002). In conclusion, an enhanced % muscular area and presumed vascular elasticity was associated with increased renal mass in all infants. Umbilical artery histomorphometry provides a link between the intrauterine environment, vascular and kidney development.

Impact of early- and late-onset preeclampsia on features of placental and newborn vascular health

INTRODUCTION

Offspring exposed to preeclampsia (PE) show an increased risk of cardiovascular disease in adulthood. We hypothesize that this is mediated by a disturbed vascular development of the placenta, umbilical cord and fetus. Therefore, we investigated associations between early-onset PE (EOPE), late-onset PE (LOPE) and features of placental and newborn vascular health.

METHODS

We performed a nested case-control study in The Rotterdam Periconceptional Cohort, including 30 PE pregnancies (15 EOPE, 15 LOPE) and 218 control pregnancies (164 uncomplicated controls, 54 complicated controls including 28 fetal growth restriction, 26 preterm birth) and assessed macroscopic and histomorphometric outcomes of the placenta and umbilical cord.

RESULTS

A significant association was observed between PE and a smaller umbilical vein area and wall thickness, independent of gestational age and birth weight. In EOPE we observed significant associations with a lower weight, length and width of the placenta, length of the umbilical cord, and thickness and wall area of the umbilical vein and artery. These associations attenuated after gestational age and birth weight adjustment. In LOPE a significant association with a larger placental width and smaller umbilical vein wall thickness was shown, independent of gestational age and birth weight.

DISCUSSION

Our study suggests that PE is associated with a smaller umbilical cord vein area and wall thickness, independent of gestational age and birth weight, which may serve as a proxy of disturbed cardiovascular development in the newborn. Follow-up studies are needed to ultimately predict and lower the risk of cardiovascular disease in offspring exposed to PE.

Morphometric characteristics of the umbilical cord and vessels in fetal growth restriction and pre-eclampsia

BACKGROUND

Reports on the morphometric analysis of umbilical cord (UC) and its vessels have been inconsistent due to varying inclusion criteria and methodology. The current study tried to overcome the limitations of previous studies by comparing the UC in pregnancies complicated by fetal growth restriction (FGR), preeclampsia (PE) and FGR+PE, to healthy controls.

AIMS

Analyze the morphometric attributes of the UC in pregnancies complicated by FGR and PE.

STUDY DESIGN

Case-control.

SUBJECTS

The study groups consisted of 36 patients with FGR+PE, 72 with FGR (without PE) and 15 with PE (without FGR). They were compared to 50 patients without FGR or PE.

OUTCOME MEASURES

Histological cross-sections of the UC were photographed and measured. The following variables were recorded: cross-section area of UC, thickness and surface area of umbilical vessel walls, shortest distance between cord surface and nearest artery (DSA), distance between the arteries (DBA) and placental weight and measurements. The area of the Wharton's jelly (WJ) area was calculated.

RESULTS

UC and WJ cross-section areas were significantly smaller in FGR+PE and FGR, but not in PE. The umbilical vessel wall area was decreased in FGR+PE, but the thickness was not significantly decreased in all three study groups, compared to controls. DSA was smaller in all three groups, whereas DBA was not significantly different, compared to controls.

CONCLUSIONS

Smaller UC cross-section areas were seen in FGR and FGR+PE, but not in PE without FGR. However, there is no evidence to determine whether this reduction is a cause or consequence of FGR. Reduced DSA in PE, whose UC cross-section area was not smaller as in FGR and FGR+PE, might reflect alterations in UC induced by PE.

Umbilical cord and preeclampsia

INTRODUCTION

Preeclampsia is associated with abnormalities in the umbilical cord in several ways: morphological, biochemical and functional. Alteration in blood vessels of the placenta, decidua and circulatory system of the fetus might be related to factors that cause preeclampsia and may be associated with alterations of the umbilical cord.

OBJECTIVES

This study aimed to analyze the relationship between each type of umbilical cord abnormality and the different subtypes of hypertensive gestational disorders.

METHODS

We conducted a prospective study on consecutive autopsies and its placentas, looking for abnormalities in the umbilical cord's features and their clinical associations.

RESULTS

Umbilical cord abnormalities including length, diameter, insertion, entanglements, knots and coils were associated with maternal gestational hypertension.

CONCLUSION

In women with gestational hypertension, umbilical cord abnormalities are associated with fetal and neonatal consequences.

Tissue-specific DNA methylation profiles in newborns

Background

Epidemiological studies demonstrate that foetal growth restriction and low birth weight affect long-term health. Derangements in tissue-specific epigenetic programming of foetal and placental tissues are a suggested underlying mechanism of which DNA methylation is best understood. DNA methylation has been mostly investigated in DNA from white blood cells. To improve baseline understanding of tissue-specific DNA methylation, we examined variation in DNA methylation profiles of the imprinted foetal growth genes IGF2 and H19 in three different tissues from the same newborn obtained at the same time.

Findings

We obtained DNA from umbilical cord blood mononuclear cells (MNC; CD34⁺ and CD34^–, n = 6), foetal side of the placenta (n = 5) and umbilical cord Wharton jelly (n = 5). DNA methylation of the IGF2 differentially methylated region (DMR) and H19 DMR was measured using quantitative mass spectrometry. Analysis of variance testing showed no statistical difference between total mean methylation of CD34⁺ and CD34^– MNC. Further comparisons were made with the pooled total MNC fraction. Mean IGF2 DMR methylation of Wharton jelly was 1.3 times higher (P = 0.001) than mean methylation of the pooled MNC. Placental mean methylation was 0.8 times lower (P <0.001) and Wharton jelly 0.9 times lower (P <0.001) than the pooled MNC of H19 DMR.

Conclusion

The total MNC fraction is a rather homogeneous cell population for methylation studies of imprinted genes in umbilical cord blood white blood cells, but may not always reflect the methylation levels of IGF2 and H19 in other organs.

Bone histomorphometry using free and commonly available software

AIMS

Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially available programs that measure histomorphometric parameters can be cost-prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program.

METHODS AND RESULTS

Image J and Adobe Photoshop(®) were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner's trichrome-stained femurs were used to generate black-and-white image masks, representing bone and non-bone tissue, respectively, in Adobe Photoshop(®) . The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and differences found to be statistically non-significant.

CONCLUSIONS

The wide-ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially available software program.