Expression of urocortin and corticotrophin-releasing hormone receptor-2 in patients with intrahepatic cholestasis of pregnancy

Stress regulation of WFS1 and PERK-p-eIF2α-ATF4 signaling pathway in placental tissue cells of intrahepatic cholestasis of pregnancy

INTRODUCTION

The placental tissue stress of intrahepatic cholestasis of pregnancy (ICP) is activated by ERS under hypoxia condition. PERK signaling pathway is the key pathway for UPR regulation, and is first to activated during ERS. WFS1, as an important regulatory gene of UPR pathway, participates in ERS regulation. The purpose of our study is to explore the expression level and mutual regulation mechanisms of WFS1 and PERK-mediated UPR pathway in ICP placental tissue cell under stress.

METHODS

Blood and placenta samples were obtained from the ICP patients and ethinylestradiol (EE)-induced intrahepatic cholestasis pregnant rats. IHC and WB were used to detect the expression of WFS1, key factors of PERK pathway (GRP78, PERK, eIF2a, P-eIF2α, ATF4) and placental stress peptides (CRH, UCN). Furthermore, qPCR was carried out to detect mRNA expression of above indicators.

RESULTS

The expression levels of WFS1 and key factors of PERK pathway were significantly increased in severe ICP placental tissues. Moreover, qPCR and WB showed that relative mRNA and protein expression levels of WFS1 and key factors of PERK pathways in placenta tissues of severe ICP and EE-induced intrahepatic cholestasis pregnant rats were higher than those in control group to varying degrees, while CRH and UCN were descended. Meanwhile, after WFS1-siRNA targeted silencing of the WFS1 gene, the protein expression levels of PERK, P-eIF2α, ATF4 were significantly increased, while CRH and UCN protein were significantly decreased.

DISCUSSION

Our study revealed that the activation of WFS1 and PERK-p-eIF2α-ATF4 signaling pathway may contribute to stress regulation in placental tissue cells of intrahepatic cholestasis of pregnancy, thereby avoiding adverse pregnancy outcomes.

Maternal Steroids on Fetal Doppler Indices, in Growth-Restricted Fetuses with Abnormal Umbilical Flow from Pregnancies Complicated with Early-Onset Severe Preeclampsia

Corticoids are largely used for fetal interest in expected preterm deliveries. This study went further, evaluating the effect of maternal administration of dexamethasone (Dex) on the umbilical artery (UA), middle cerebral artery (MCA), and ductus venous (DV) spectrum, in growth-restricted fetuses, with the absent end-diastolic flow (AEDF) in UA, from singleton early-onset severe preeclamptic pregnancies. Supplementary, the impact on both uterine arteries (UTAs) flow was also evaluated. In 68.7% of cases, the EDF was transiently restored (trAEDF group), in the rest of 31.2% remained persistent absent (prAEDF group). UA-PI significantly decreased in the first day after Dex (day 1/0; p < 0.05), reaching its minimum during day 2 (day 2/1; p > 0.05), revealing a significant recovery to day 4 (day 4/2; p < 0.05), in both groups. The MCA-PI decreased from day 1 until day 3 in both groups, but significantly only in the trAEDF group (p = 0.030 vs. p = 0.227. The DV-PI's decrease (during day 1) and the CPR's increase (between days 0 and 2) were not significant in both groups. UTAs-PIs did not vary. The prAEDF group had a significantly increased rate of antenatal worsening Doppler and a poorer perinatal outcome compared with the trAEDF group. In conclusion, Dex transiently restored the AEDF in UA in the majority of cases, a "positive" effect being a useful marker for better perinatal prognosis. UA-PI significantly decreased in all cases. The improvement in umbilical circulation probably was responsible for the short but not significant DV-PI reduction. MCA-PI decreased only in sensitive cases, probably due to an already cerebral "full" vasodilation in the prAEDF group. Furthermore, the CPR's nonsignificant improvement was the result of a stronger effect of Dex on UA-PI than on MCA-PI. Finally, despite the same etiology, it was only a weak correlation between the severity of the umbilical and uterine abnormal spectrum.

Dexamethasone on absent end-diastolic flow in umbilical artery, in growth restricted fetuses from early-onset preeclamptic pregnancies and the perinatal outcome

BACKGROUND

Absent end-diastolic flow (AEDF) in the umbilical artery (UA) worsens the already poor prognosis of growth-restricted fetuses (GRFs) in pregnancies complicated by early-onset preeclampsia with severe features (ESP).

METHOD

We assessed the correlation between the effect of maternal dexamethasone (Dex) on AEDF in the UA and perinatal outcomes, in 59 GRFs from EPS-complicated pregnancies. The maternal outcome was also evaluated.

RESULTS

The mean maternal age at inclusion was 22.4 ± 5.9 years. Dex transiently restored EDF in the UA in 38 (64.4%) cases (trAEDF group), but in 21 (35.6%) patients, the flow was persistently absent (prAEDF group). The effect lasted up to the 4th day.The gestational age at diagnosis, number of days from admission until delivery, and fetal weight were significantly lower in the prAEDF group than in the trAEDF group (p < .05). The same group had a significantly increased rate of fetal proximal deterioration, low APGAR scores, neonatal hypoxia, assisted ventilation, mild intraventricular haemorrhage (I/II), and respiratory distress syndrome, as well as maternal deterioration, especially in cases of resistant hypertension (p < .05). Although the rates of fetal acidemia and perinatal mortality in the prAEDF group were respectively three times and two times higher, the differences were not significant (p > .05).

CONCLUSIONS

The Dex no-effect on UA Doppler in GRFs with AEDF in the UA, in EPS-complicated pregnancies, can be a useful marker for a higher risk of proximal fetal deterioration, poor state at delivery, neonatal hypoxic complications, and worsening maternal condition, but not for perinatal mortality. The findings also highlight the alarmingly younger age of patients with EPS. Finally, all these pregnancies should be monitored in a complex multidisciplinary manner in tertiary referral units.Key messageThe effect of dexamethasone on absent end-diastolic flow in the umbilical artery in growth-restricted fetuses from pregnancies complicated by early-onset preeclampsia with severe features can be a useful prognostic factor for perinatal outcomes.

State of the Art in Hepatic Dysfunction in Pregnancy

Hepatic dysfunction in pregnant women is always challenging for the obstetrician, as the spectrum of hepatic abnormalities can be very large and have various implications, both for mother and fetus. There is a diagnostic and therapeutic polymorphism of hepatic dysfunction in pregnancy and insufficient knowledge related to the etiopathogenesis and epidemiology of this disease. The clinical forms of hepatic dysfunction encountered in pregnancy can vary from liver diseases related to pregnancy (e.g., HELLP syndrome, intrahepatic cholestasis, hyperemesis gravidarum, or acute fatty liver of pregnancy) to de novo ones occurring in pregnancy, and pre-existing liver disease (cholelithiasis, Budd-Chiari syndrome, and cirrhosis). We performed a systematic literature search over 10 years. The review protocol assumed a search of two databases (PubMed®/MEDLINE and Web of Science Core Collection). The strategy regarding the management of these diseases involves multidisciplinary teams composed of different specialists (obstetricians, gastroenterologists and anesthetists) from specialized tertiary centers. Despite the improving prognosis of pregnant women with liver diseases, the risk of maternal-fetal complications remains very high. Therefore, it is necessary to ensure careful monitoring by a multidisciplinary team and to inform the patients of the potential risks.

Molecular Pathogenesis of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease. The maternal symptoms are characterized by skin pruritus and elevated bile acids, causing several adverse outcomes for fetuses, including an increased risk of preterm birth, meconium-stained amniotic fluid, neonatal depression, respiratory distress syndrome, and stillbirth. Genetic, hormonal, immunological, and environmental factors contribute to the pathogenesis of ICP, and the estrogen-bile acid axis is thought to play a dominant role. The advances in the past 10 years uncover more details of this axis. Moreover, dysregulation of extracellular matrix and oxygen supply, organelle dysfunction, and epigenetic changes are also found to cause ICP, illuminating more potential drug targets for interfering with. Here, we summarize the molecular pathogenesis of ICP with an emphasis on the advancement in the past 10 years, aiming to give an updated full view of this field.

Disrupted compensatory response mediated by Wolfram syndrome 1 protein and corticotrophin-releasing hormone family peptides in early-onset intrahepatic cholestasis pregnancy

INTRODUCTION

The most adverse perinatal outcome of intrahepatic cholestasis of pregnancy (ICP) is sudden fetal death related to acute fetoplacental hypoxia. Corticotrophin-releasing hormone (CRH), urocortin (UCN), and Wolfram syndrome 1 (WFS1) proteins may have a compensatory response to hypoxic stress.

METHODS

A total of 108 singleton pregnant women were divided into three groups: control, late-onset ICP, and early-onset ICP. Enzyme-linked immunosorbent assays were used to detected maternal serum CRH, UCN, and WFS1 levels. Western blotting and real-time polymerase chain reaction were conducted to quantify placental protein and mRNA levels of CRH, UCN, and WFS1. Pearson correlation scatterplots and Pearson correlation matrix were employed to testify the correlation.

RESULTS

Placental WFS1 had a positive relation with placental UCN (r = 0.69, P < 0.05) and serum UCN (r = 0.36, P < 0.05). Placental CRH was positively correlated with maternal serum CRH (r = 0.53, P < 0.05). Maternal serum and placental levels of CRH, UCN, and WFS1 significantly increased in the early-onset ICP group compared with the control group (P < 0.05). Placental levels of UCN and WFS1 in the early-onset ICP group were significantly elevated and higher in comparison with the late-onset ICP group (P < 0.05). However, the transcriptional levels of CRH, UCN, and WFS1 were impaired in the early-onset ICP group.

DISCUSSION

Our study revealed that transcription and translation of WFS1, CRH, and UCN were altered during pregnancies complicated by early-onset ICP. This disrupted compensatory response mediated by WFS1 and CRH family peptides in early-onset ICP may play a significant role in the pathogenesis of sudden fetal death in acute fetal hypoxia.

New insights into diagnosis and treatment of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disease, characterized by maternal pruritus and abnormal serum biochemistries in the late second and third trimester of pregnancy. The symptoms and abnormal biochemistries resolve rapidly after fetal delivery. As a diagnosis of exclusion, the diagnosis of ICP is based on unexplained pruritus with other causes and impaired liver function presenting with elevated serum liver transaminases and/or bile acids. It is considered as severe ICP when bile acid ≥ 40 μmol/L during pregnancy. The pathogenesis of ICP is still unclear. Adverse perinatal outcomes associated with ICP are focused on increased risk of preterm, meconium-stained amniotic fluid, and perinatal mortality. Unpredictable fetal hypoxia may result in intrauterine fetal death, fetal distress during birth and even stillbirth, and lead to an increase of iatrogenic preterm and cesarean section. The etiology and pathogenesis of fetal stress in ICP are not yet clarified, which may be associated with impaired infrastructure and decreased stress-compensatory in human utero-placental-fetal unit, and related with vascular constriction of chorionic veins and umbilical cord due to elevated bile acids in fetal serum and amniotic fluid. The essential measures of standard treatment of ICP include: (1) monitoring and evaluation of disease, uterine contraction and fetus; (2) prevention and treatment of uterine contraction; (3) treatment with ursodeoxycholic acid (500-1500 mg/d) alone or in combination with S-adenosylmehionine (800-1000 mg/d) or rifampicin (300-1200 mg/d) to promote drainage of bile acids; (4) promotion of fetal growth and lung development; (5) treatment with vitamin K1 before delivery to prevent maternal and fetal hemorrhage; (6) and timely termination of pregnancy. Gestational weeks, fetal condition and severity of disease need to be taken into account when obstetricians decide the time of termination. Elective early delivery is still an effective measure to avoid stillbirth during prolongation of gestational weeks.

Dynamic expression of corticotropin-releasing hormone and urocortin in estrogen induced-cholestasis pregnant rat

Intrahepatic cholestasis of pregnancy(ICP) is complicated by acute placental-fetal hypoxia. Corticotropin-releasing hormone(CRH) and urocortin(UCN) are vasodilatory regulators of blood flow in the placenta. An ethinylestradiol(EE)-induced cholestasis rat model was reproduced and serum/placental CRH/UCN were detected during 14-21days of gestation(DG). Maternal serum or placental CRH/UCN levels in the control rats were relatively consistent during 14-21DG. Serum CRH was reduced in the EE-treated rats compared with the control rats at 21DG. Regarding serum UCN, we observed a decrease at 17DG as well as an increase at 21DG in the EE-treated rats compared with the controls. Moreover, we observed a noticeable reduction of placental CRH/UCN expression at 17 or 19DG in the EE-treated rats compared with the control rats. The serum bile acids levels exhibited an inverse correlation with placental CRH/UCN expression. EE-induced cholestasis rats might serve as a good model to further investigate the pathological mechanism underlying CRH/UCN dysregulation in ICP.

The pathophysiology of intrahepatic cholestasis of pregnancy

A number of liver disorders are specific to pregnancy. Amongst these, intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis (OC), is the commonest, affecting approximately 1 in 140 UK pregnancies. Patients commonly present in the third trimester with severe pruritus and deranged serum liver tests; bile acids are elevated, in severe cases >40 μmol/L. Although the disease is considered relatively benign for the mother, increased rates of adverse fetal outcomes, including stillbirth, are associated with ICP. As our knowledge of the mechanisms underlying bile acid homeostasis has advanced in the last 15 years our understanding of ICP has grown, in particular with respect to genetic influences on susceptibility to the disease, the role of reproductive hormones and their metabolites and the possible identity of the pruritic agents. In this review, we will describe recent advances in the understanding of this condition with a particular emphasis on how aspects of genetic and reproductive hormone involvement in pathophysiology have been elucidated. We also review recent developments regarding our knowledge of placental and fetal pathophysiology and the long-term health consequences for the mother and child.