Increased expression levels of E-cadherin,cytokeratin 18 and 19 observed in preeclampsia were not correlated with disease severity

Introduction

Preeclampsia is a pregnancy-specific disorder and placental factor(s) contribute to the pathogenesis of preeclampsia. Turnover of villous trophoblast is affected by impaired placental perfusion in preeclampsia. Expression and localisation of cadherins and cytokeratins are involved in the pathogenesis of preeclampsia. However, studies describing the associations between cadherins and cytokeratins in preeclampsia are limited. The aim of this study was to investigate the expression of E-cadherin, N-cadherin, cytokeratin 18 and cytokeratin 19 in placentae from women with preeclampsia in order to determine whether their expression differs with disease severity.

Methods

29 preeclamptic placentae and 25 normotensive placentae were included in this study. The expression of E-cadherin, cytokeratin 18, cytokeratin 19 andN-cadherin was quantified by immunohistochemistry and western blotting.

Results

E-cadherin, cytokeratin 18 and cytokeratin 19 were expressed predominantly in the syncytiotrophoblast of the placenta and the expression of E-cadherin, cytokeratin 18 and cytokeratin 19 was significantly increased in preeclampsia compared to normotensive pregnancies. However, there was no significant difference in expression between severe preeclampsia and mild preeclampsia. In addition, there was no difference in the expression of N-cadherin between preeclampsic and normotensive pregnancies.

Discussion

Our data demonstrated increased expression of E-cadherin, cytokeratin 18 and cytokeratin 19 in the syncytiotrophoblast of preeclamptic placentae, but this increase was not correlated with disease severity.

Conclusion

Our data suggests that E-cadherin and cytokeratins are involved in the pathogenesis of preeclampsia.     

Trophoblast debris extruded from preeclamptic placentae activates endothelial cells: A mechanism by which the placenta communicates with the maternal endothelium

Introduction

Preeclampsia is characterized by maternal endothelial dysfunction. While the mechanisms leading to preeclampsia are unclear, a factor(s) from the placenta is responsible for triggering the disease. One placental factor implicated in triggering preeclampsia is trophoblast debris which may transmit pathogenic signals from the placenta to endothelial cells. In this study, we investigated whether trophoblast debris from preeclamptic placentae triggered endothelial cell activation.

Methods

Trophoblast debris from preeclamptic or normotensive placentae, or trophoblast debris from normal placental explants that had been cultured with preeclamptic (n = 14) or normotensive sera (n = 14) was exposed to endothelial cells. Activation of the endothelial cells was quantified by cell surface ICAM-1 and U937 adhesion to endothelial cells. The levels of IL-1β, pro-caspase-1 and active caspase-1 in the trophoblast debris were measured.

Results

Compared to controls, the levels of ICAM-1 and U937 adhesion to endothelial cells were significantly increased following exposure of the endothelial cells to trophoblast debris from preeclamptic placentae or placentae treated with preeclamptic sera. The levels IL-1β, pro-caspase-1 and active caspase-1 were significantly increased in both trophoblast debris from preeclamptic placentae and placentae treated with preeclamptic sera.

Discussion

These results provide the first direct evidence that trophoblast debris produced from preeclamptic placentae or placentae treated with preeclamptic sera can activate the endothelium.

Conclusions

Trophoblast debris from preeclamptic but not normotensive placentae can induce endothelial cell activation. This may be one mechanism by which the preeclamptic placenta communicates with the maternal endothelium to induce activation of the endothelium.     

Expression profiling of vitamin D receptor in placenta, decidua and ovary of pregnant mice

Objectives

The presence of vitamin D receptor (VDR) and the identification of localized vitamin D3 synthesis in placenta and decidua implicate the importance of vitamin D3 in reproductive function. There is, however, no data on the expression profile of VDR in the mouse placenta and endometrium throughout the pregnancy period.

Study design

In the present work expression of VDR in reproductive tissues of pregnant mice at different gestational phases has been addressed. Expression of VDR was determined by semi-quantitative RT-PCR, Western blotting and immunohistochemistry.

Results

The results showed that VDR mRNA and protein were expressed in decidua, placenta and ovary throughout the pregnancy. VDR gene expression in placenta was significantly elevated in late pregnancy when compared to that of mid pregnancy. Additionally, VDR expression level in decidua rose significantly as pregnancy progressed from early to mid stages. VDR expression in decidua of pregnant mice was higher in comparison to endometrium of non-pregnant mice. Immunohistochemical analysis revealed that VDR protein is consistently expressed by luminal and glandular epithelial cells of decidua, giant cells, glycogen rich cells and labyrinth cells of placenta and by almost all follicular cell types of ovary. Surveying the expression of VDR at the protein level by Western blotting confirmed PCR results.

Conclusion

It seems that expression of VDR in reproductive organs is finely tuned during pregnancy indicating its eminent role in reproductive biology.     

Antioxidant gene expression in preeclamptic placentae: a preliminary investigation

Oxidative stress has been implicated in the pathogenesis of preeclampsia. This study measured the relative mRNA expression of antioxidant proteins glutathione peroxidase 1 and 4, glutathione reductase, thioredoxin 1 and 2, thioredoxin reductase 1, thioredoxin peroxidase 3 and superoxide dismutase 1 and 2 in preeclamptic and non-preeclamptic placentae. Quantitative real-time PCR was conducted on placental mRNA isolated from preeclamptic and control patients. Cycle threshold numbers and fold differences were calculated as a measure of linear product amplification and used for comparison. The mRNA expression of glutathione reductase was significantly reduced (fold difference 0.41, p<0.05) in preeclamptic placenta when compared to controls while the expression of thioredoxin peroxidase 3 was significantly increased (fold difference 3.25, p<0.001) in the preeclamptic placentae. No significant difference in expression was observed for glutathione peroxidase 1 and 4, thioredoxin 1 and 2, thioredoxin reductase 1 and superoxide dismutase 1 and 2. These results suggest that it is the abnormal oxidative insult associated with preeclampsia not mRNA expression of antioxidant proteins that may be responsible for reduced antioxidant enzyme activity in preeclamptic placentae.     

Evidence for insulin-mediated control of AQP9 expression in human placenta

The AQP9 gene contains a negative insulin response element, suggesting that it may be modulated by insulin. Previously, we reported AQP9 overexpression in preeclamptic placentas but a lack of functionality of AQP9 in water and mannitol transport. We also observed high serum levels of insulin and TNF-α in preeclamptic women.

Objective

To evaluate whether AQP9 expression is regulated by insulin in the human placenta, and whether the dysregulation of AQP9 observed in preeclamptic placentas may be related to the inability to respond to insulin stimuli.

Methods

Explants from normal and preeclamptic placentas were cultured at different concentrations of insulin. Treatment with TNF-α was used to induce phosphorylation of insulin receptor substrate (IRS), which may desensitize insulin action. AQP9 molecular expression and water uptake was determined.

Results

Insulin decreased the molecular expression of AQP9 exclusively in explants from normal placentas in a concentration-dependent manner. Treatment with TNF-α previous to insulin addition prevented these changes. Moreover, insulin treatment did not modify water uptake neither its sensitivity to HgCl_2.

Conclusion

AQP9 water permeability seems to be independent of its molecular expression, strongly suggesting that AQP9 might not have a key role in water transport in human placenta. We also propose another mechanism of down-regulation of AQP9 molecular expression mediated by insulin in a concentration-dependent manner in human placenta and provide new evidence that in preeclamptic placentas the mechanisms of insulin signaling may be altered, producing an overexpression of AQP9 that does not correlate with an increase in its functionality.     

Flujo sanguíneo de las arterias renales fetales en preeclámpticas graves y embarazadas normotensas sanas

Objective

To compare the blood flow in fetal renal arteries in severe preeclamptic and healthy normotensive pregnant women.

Method

The sample consisted of 30 women with severe preeclampsia (group A) and 30 healthy normotensive pregnant women (group B) with single pregnancies of more than 30 weeks. The pulsatility and resistance indexes of the uterine, umbilical, fetal middle cerebral and fetal renal arteries were measured.

Results

There were no significant differences in maternal age, gestational age or newborn weight (p = ns). Pulsatility and resistance index values in the uterine and umbilical arteries were significantly higher and both measurements for the fetal middle cerebral artery were significantly lower in group A than in group B (p = 0.0001). Pulsatility and resistance index values in the fetal renal artery were significantly higher in group A than in group B (p = 0.0001). The fetal renal artery pulsatility index was significantly correlated with the pulsatility index of the uterine artery (p = 0.011) and the fetal middle cerebral artery (p < 0.007). The fetal renal artery resistance index was correlated with the resistance index of the three vessels (p < 0.05).

Conclusion

Women with severe preeclampsia show blood flow alterations in the fetal renal arteries compared with healthy normotensive pregnant women.     

Comparison of pregnancy outcome among nulliparas with and without microalbuminuria at the end of the second trimester

Objective

To evaluate the rate of poor pregnancy outcome among nulliparas who had microalbuminuria at the end of the second trimester of their pregnancy.

Methods

A prospective cohort study was performed on 490 nulliparous women who were at the end of the second trimester of pregnancy. Urine tests for albuminuria and creatinine measurements were performed in all women and the albumin to creatinine ratio (ACR) was calculated. The women with microalbuminuria (exposed group) and those without microalbuminuria (nonexposed group) were monitored until the end of their pregnancy and compared for pregnancy outcome.

Results

Preterm labor (57.9% versus 13.5%), preeclampsia (50.0% versus 8.6%), intrauterine growth restriction (42.1% versus 6.4%), and preterm premature rupture of membranes (31.6% versus 10.2%) were significantly more common in the exposed group. The rates of gestational diabetes did not differ significantly between the 2 groups. In multivariate logistic regression analyses, microalbuminuria increased the risks for preterm labor (adjusted OR 2.4; 95% CI 1.1-5.5, P = 0.03) and preeclampsia (adjusted OR 9.5; 95% CI 4.6-19.3, P < 0.001).

Conclusion

Microalbuminuria at the end of the second trimester of pregnancy might increase the risks of preterm labor, preeclampsia, intrauterine growth restriction, and preterm premature rupture of membranes.     

Placental leptin in HIV-associated preeclampsia

Objective

HIV-associated preeclampsia reflects a combination of opposing influences on the immune status. The adipocyte hormone leptin has been implicated in the pathophysiology of preeclampsia and in enhancing immunity. This study is the first, to our knowledge, to determine whether leptin levels in the placenta differ between HIV-associated normotensive and preeclamptic pregnancies. The study also compares leptin levels between the exchange and conducting areas of the placenta.

Study design

Pregnant women were recruited antenatally and grouped as follows: normotensive HIV uninfected (n = 30), normotensive HIV infected (n = 60), preeclamptic HIV uninfected (n = 30) and preeclamptic HIV infected (n = 60). Anthropometric data were collected and placental leptin was analysed by immunohistochemistry and ELISA.

Results

Leptin levels were similar in the central and peripheral regions of the placenta. Leptin immunoreactivity was observed amongst the different trophoblast cell populations. Both ELISA and immunohistochemistry of the placental exchange villi indicated that leptin levels were higher in preeclampsia compared to normotensive pregnancies (p < 0.001). HIV status had no effect on leptin levels but levels were higher in participants on highly active antiretroviral treatment (HAART) compared to those on prophylaxis for prevention of mother to child transmission (PMTCT) with normotensive (p = 0.006) and preeclamptic (p = 0.002) pregnancies. The area of immunostaining was greater in the exchange compared to the conducting villi in HIV infected and uninfected preeclampsia.

Conclusions

This novel study establishes an elevation of leptin in preeclamptic placentae, irrespective of HIV status. Leptin elevation was not focal in that it occurred in both central and peripheral regions of the preeclamptic placenta. This suggests a role of leptin in the pathophysiology of preeclampsia.     

Regulation by hypoxia of adrenomedullin output and expression in human trophoblast cells

Objectives

Plasma adrenomedullin concentrations are increased in the fetal circulation in acute and chronic hypoxic conditions. The effect of hypoxia in regulating adrenomedullin synthesis and secretion was investigated in human placental trophoblast cells.

Study design

Human trophoblast cells obtained from term placentas (n = 7) were cultured in hypoxic condition (3% oxygen). Cytotrophoblast cells were cultured for up to 48 h and syncytiotrophoblasts for 2, 8 and 24 h. Changes in adrenomedullin output compared to normoxic conditions were measured by radioimmunoassay. Protein expression was evaluated with Western blot and immunocytochemistry.

Results

Hypoxia induced a time-dependent increase in adrenomedullin output and protein expression by placental trophoblast cells.

Conclusions

Hypoxia regulates adrenomedullin secretion and expression by human placenta, thereby promoting increased adrenomedullin concentration in the fetal circulation in clinical circumstances characterized by reduced oxygen levels.     

Fertility and obstetric outcome after conservative management of placenta accreta

Objective

To determine the fertility and obstetric outcomes after conservative management of placenta accreta.

Methods

A retrospective observational cohort study of all identified cases of placenta accreta from 1993 to 2007 in 2 tertiary university hospitals in France. For patients treated conservatively, maternal and fetal morbidity, reproductive function, fertility, and subsequent pregnancies were recorded.

Results

During the study period, 46 patients were treated by conservative management; 6 patients underwent a secondary hysterectomy. Of the remaining 40 patients, 35 were followed up for a median of 65 months (range 18-156 months). Patients resumed their menstrual cycles after a median of 130 days (range 48-176 days). Menses were irregular in 11 patients (31%), but none had amenorrhea. Twelve of the 14 patients desiring another pregnancy achieved a total of 15 pregnancies; 2 patients had recurrent placenta accreta. Five spontaneous abortions and 1 termination of pregnancy occurred during the first trimester. The median term at delivery was 37 weeks (range, 35-40 weeks). Four patients delivered prematurely.

Conclusion

Conservative management of placenta accreta can preserve fertility, although the risk of recurrent placenta accreta appears to be high.     

Young mothers who choose to breast feed: the importance of being part of a supportive breast-feeding community

Objective

to examine factors associated with breast-feeding initiation and duration in young mothers (≤24 years).

Design

a retrospective questionnaire completed between six and 24 months post partum.

Setting

mothers were recruited from local mother and infant groups, nurseries and online mother and infant forums.

Participants

138 mothers aged between 17 and 24 years (mean age 21.93 years)

Measurements and findings

participants completed a retrospective questionnaire about their experience of breast or artificial milk feeding during the first six months post partum. A further 10 mothers who breast fed for at least six months completed a semi-structured interview. Breast feeding for at least six months was positively associated with attending a breast-feeding support group, believing breast feeding to be easy, being part of an environment where breast feeding is normative, and being encouraged to breast feed by others.

Key conclusions

themes raised highlight the importance of viewing breast feeding as the normal way to feed an infant and having others support the mother in this behaviour.

Implications for practice

increasing breast-feeding initiation and duration among this at-risk group is important for both infant and maternal health. Helping mothers to view breast feeding as the norm, creating an environment where breast feeding is accepted, providing professional and peer support, and encouraging the mother to continue breast feeding are important steps in raising breast-feeding rates among younger mothers.     

The secretion of PAPP-A, ADAM12, and PP13 correlates with the size of the placenta for the first month of pregnancy

Objectives

Pregnancy Associated Protein A (PAPP-A), A Disintegrin and Metalloproteinase 12 (ADAM12) and Placental Protein 13 (PP13) are secreted from the placental trophoblastic tissue and are involved in normal implantation and placental development. The aim of the study was to assess the connection between the secretion of these proteins and the growth of the gestational sac and the placenta.

Study design

In an observational longitudinal study at Oulu University Hospital, women with naturally conceived pregnancies were followed-up weekly to pregnancy week 11.

Main outcome measures

PAPP-A, ADAM12 and PP13 serum concentrations and their correlation with the volumes of the gestational sac and the placenta were assessed using three-dimensional ultrasonography.

Results

The study group consisted of 41 women. The PAPP-A, ADAM12 and PP13 serum concentrations increased continuously from pregnancy week 4 to week 11 and correlated closely with each other. The serum concentrations of PAPP-A, ADAM12 and PP13 also correlated with the volumes of the gestational sac and the placenta up to pregnancy week 8.

Conclusions

The secretion of PAPP-A, ADAM12 and PP13 is closely related to the size of the placenta in the beginning of pregnancy. After 8 weeks of pregnancy, which is the time for luteoplacental shift, the correlation disappears, possibly reflecting the morphologic transformation in the placenta.     

Comparison of serum and urinary nephrin levels between normal pregnancies and severe preeclampsia

Objective

To compare the levels of urinary excretion of nephrin in women experiencing either normotensive or severe preeclamptic pregnancies, and to examine the relationship between urinary nephrin levels and clinical parameters of preeclampsia.

Study design

In a case control study we collected serum and urine specimens from women with normal pregnancy (n = 30) and from women with severe preeclampsia (n = 43). Serum nephrin levels and urinary nephrin concentrations were measured in all patients.

Results

Both serum and urine concentrations of nephrin were significantly higher in the severe preeclamptic group than in the normal pregnancy group. In addition, we identified a significant relationship between urinary nephrin levels and urine protein concentrations in the severe preeclamptic group. Urine nephrin concentrations were also correlated with serum creatinine levels and with diastolic blood pressure in the severe preeclamptic group.

Conclusion

The positive correlations observed in this study suggest that urinary nephrin excretion might play an important role in the pathogenesis of proteinuria during preeclampsia and could be a good indicator of renal damage.     

Decreased expression of complement 3a receptor (C3aR) in human placentas from severe preeclamptic pregnancies

Objectives

The aim of this study was to determine the expression of the anaphylatoxin receptors complement C3a receptor (C3aR) and C5a receptor (C5aR) in the placentas of pregnancies complicated by severe early onset preeclampsia.

Study design

We recruited women with pregnancies complicated by severe early-onset preeclampsia (n = 19, 11 of which were further complicated with IUGR) and women with preterm pregnancies not affected by preeclampsia (n = 8). Gene and protein expression of C3aR and C5aR was analysed by quantitative RT-PCR and Western blotting, respectively.

Results

C3aR was detected in the Hofbauer cells in the villous stroma of the placenta. C5aR staining was detected in the syncytiotrophoblast and endothelial cells. We found significantly decreased expression of C3aR mRNA and protein expression in placentas with preeclampsia compared to controls. However, C5aR expression was not significantly different between preeclamptic and control placentas at either the mRNA or protein level.

Conclusions

Decreased C3aR expression indicates a dysregulation of the complement system in the placentas of preeclamptic women. Further studies would elucidate the exact mechanisms that complement has in preeclampsia.     

Concentraciones de interleucina 4 en preeclámpticas y embarazadas normotensas sanas

Objective

To compare concentrations of interleukin-4 in patients with preeclampsia and healthy normotensive pregnant women.

Material and methods

One hundred patients were selected. Fifty preeclamptic patients were selected as cases (group A) and 50 healthy pregnant women with a similar age and body mass index to those in the study group were selected as controls (group B). Blood samples for interleukin-4 determination were collected in all patients before labor and immediately after diagnosis in the study group.

Results

There were no significant differences in maternal or gestational age or body mass index at sample collection (p=ns). Significant differences were found between groups in mean values of systolic and diastolic blood pressure (p<0.05). Statistically significant differences were also found in interleukin-4 concentrations in patients in group A (10.0±2.4 pg/ml) and those in group B (13.2±1.5 pg/ml; p<0.05) and a moderate, negative and significant correlation was found with systolic (r=−0.574; p<0.05) and diastolic blood pressure (r=−0.541; p<0.05).

Conclusion

Interleukin-4 concentrations of were significantly lower in preeclamptic patients than in healthy normotensive pregnant women.     

Soluble endoglin production is upregulated by oxysterols but not quenched by pravastatin in primary placental and endothelial cells

Introduction

Preeclampsia is a serious pregnancy complication. Soluble endoglin (sEng) is released from the placenta and contributes to the maternal endothelial dysfunction seen in preeclampsia. Recently oxysterols, which activate the Liver X Receptor (LXR), have been implicated in producing sEng, by upregulating matrix metalloproteinase-14 (MMP14; cleaves endoglin to produce sEng) and down-regulating tissue inhibitor of metalloproteinase-3 (TIMP-3; inhibitor of MMP14). The functional experiments in that study were performed on JAR cells (human choriocarcinoma cell line) and placental explants.

Methods

We characterized LXR in severe preeclamptic placentas, and assessed whether oxysterols increase release of sEng from primary human umbilical vein endothelial cells (HUVECs), primary trophoblasts and placental explants. Given pravastatin is thought to block oxysterol production and inhibit the LXR, we examined whether pravastatin reduces sEng release.

Results

LXRα and β were localized to the syncytiotrophoblast and villous tips and were significantly up-regulated in preeclamptic placenta. Oxysterols upregulated sEng production in HUVECs and placental explants although the increases were far more modest than that recently reported. Oxysterols did not upregulate sEng in primary trophoblasts. Furthermore, mRNA expression of MMP14 and TIMP-3 were not altered by oxysterols in any tissue. Surprisingly, pravastatin did not decrease oxysterol-induced upregulation of sEng.

Discussion

LXR is up-regulated in preeclamptic placenta. Oxysterols upregulate sEng production from human tissues, but the increase is modest, suggesting this may not be the main mechanism for the very significant elevations in sEng seen in preeclampsia. Pravastatin does not decrease sEng production.

Conclusion

Oxysterols modestly up-regulate sEng production which is not quenched by pravastatin.     

Intrauterine device or estrogen treatment after hysteroscopic uterine septum resection

Objective

To investigate the effects on adhesion formation and pregnancy maintenance of an intrauterine device (IUD) and/or estrogen treatment after hysteroscopic septum resection.

Methods

After septum resection 100 women received either no treatment, or estrogens, or an IUD, or an IUD plus estrogens (n = 25 per group). Most were later checked hysteroscopically for uterine cavity adhesions. All pregnancies occurring during the study period were recorded.

Results

Adhesions developed in 1 of 19 (5.3%) of the untreated women, 3 of 25 (12%) of the women treated with an IUD plus estrogens, 2 of 19 (10.5%) of the women treated with an IUD only, and none of the women treated with estrogens only. None of the differences, however, were significant. Regarding pregnancy, the differences between groups were also not significant.

Conclusion

Neither IUD placement, nor estrogen treatment, nor both were found to prevent intrauterine adhesions or facilitate pregnancy after hysteroscopic uterine septum resection.