Yoshitsugu Chigusa

Decreased Lectin-Like Oxidized LDL Receptor 1 (LOX-1) and Low Nrf2 Activation in Placenta Are Involved in Preeclampsia

CONTEXT Serum concentration of oxidized low-density lipoprotein (oxLDL) is higher in women with preeclampsia than in normal pregnant woman. Lectin-like oxLDL receptor-1 (LOX-1) is one of the scavenger receptors for oxLDL and is abundantly expressed in placenta. It is well known that oxLDL activates nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of antioxidant and cytoprotective genes such as heme oxygenase-1 (HO-1), which play an important role in preeclampsia. However, it has yet to be elucidated whether LOX-1, along with Nrf2, participates in the pathology of preeclampsia. OBJECTIVE The objective of the study was to assess LOX-1 expression and Nrf2 activation in preeclamptic placentas and to manifest their physiological roles in preeclampsia. METHODS Expression and regulation of LOX-1, HO-1, and Nrf2 were evaluated by real-time quantitative RT-PCR and Western blotting. The functions of LOX-1 and Nrf2 were examined using an anti-LOX-1 antibody and Nrf2 activator in JAR, a choriocarcinoma cell line, and placental explants. RESULTS Both LOX-1 expression and Nrf2 activation were significantly decreased in preeclamptic placentas compared with normal controls. A significant decrease in LOX-1 mRNA was found in placental explant cultures under hypoxic conditions. Activation of Nrf2 up-regulated HO-1 in both the JAR cells and placental explants. Furthermore, oxLDL increased HO-1 mRNA, whereas the blockade of LOX-1 inhibited the increase of HO-1 mRNA in JAR cells. CONCLUSION Decreasing LOX-1 expression in preeclamptic placenta may contribute to high oxLDL concentration, low Nrf2 activation, and low HO-1 expression. These findings provide novel insights into the crucial role of LOX-1 and Nrf2 in the pathogenesis of preeclampsia.

Differential expression and the anti-apoptotic effect of human placental neurotrophins and their receptors

Neurotrophin (NT) is important in the survival, maintenance and differentiation of neuronal tissue, and functions in follicle maturation, tumor growth, angiogenesis and immunomodulation; however, the expression of NT and its receptors (NTR) in human placenta and their influence on fetal growth are unclear. Here we investigated the correlation of NT and NTR in human placenta with uterine environment and fetal growth. TrkB, a NTR, mRNA was expressed on decidual and villous tissue and increased with gestational age, localizing in the trophoblast layer and endothelium by immunohistochemistry. Villous TrkB mRNA was significantly increased in preeclampsia (PE) than in controls and was higher in the normotensive small for gestational age (SGA) placenta, although it was not significant. It was also significantly increased in the small twin of discordant twin pregnancies. Brain-derived neurotrophic factor (BDNF), the main ligand of TrkB, was expressed in membranous chorion and villous tissue and was significantly higher in maternal plasma in normotensive SGA and PE than in controls. TrkB mRNA expression was up-regulated on cultured villous tissue explants and on JEG-3, a choriocarcinoma cell line, by H(2)O(2) treatment. BDNF decreased apoptotic cells in H(2)O(2)-treated JEG-3, indicating that BDNF/TrkB signaling had anti-apoptotic effects against oxidative stress in JEG-3, suggesting a protective role of BDNF/TrkB in human villous tissue under unfavorable conditions in utero.

ATP-binding cassette transporter A1 expression is decreased in preeclamptic placentas.

Preeclampsia is a pregnancy-specific multisystem disorder characterized by hypertension and proteinuria. Accentuated maternal hyperlipidemia, especially high serum levels of oxidized low-density lipoprotein (oxLDL), is one of the features of preeclampsia. We previously reported that lectin-like oxidized LDL receptor 1 (LOX-1) expression was decreased in preeclamptic placentas. Here, we show that decreased LOX-1 expression is associated with low expression of adenosine triphosphate-binding cassette transporter A1 (ABCA1) in the placenta. The ABCA1 mediates cellular efflux of cholesterol, and liver X receptors (LXRs) are its predominant transcriptional regulators. Both ABCA1 and LXR expressions were significantly lower in preeclamptic placentas than those in normal controls. Oxidized LDL upregulated ABCA1 expression, while LOX-1 blockade resulted in the alleviation of increasing ABCA1 messenger RNA in JAR cells. These results suggest that low LOX-1 expression may lead to insufficient oxLDL uptake, thereby contributing to reduced LXR activation and decreased ABCA1 expression in preeclamptic placentas.

Reliable pre-eclampsia pathways based on multiple independent microarray data sets

Pre-eclampsia is a multifactorial disorder characterized by heterogeneous clinical manifestations. Gene expression profiling of preeclamptic placenta have provided different and even opposite results, partly due to data compromised by various experimental artefacts. Here we aimed to identify reliable pre-eclampsia-specific pathways using multiple independent microarray data sets. Gene expression data of control and preeclamptic placentas were obtained from Gene Expression Omnibus. Single-sample gene-set enrichment analysis was performed to generate gene-set activation scores of 9707 pathways obtained from the Molecular Signatures Database. Candidate pathways were identified by t-test-based screening using data sets, GSE10588, GSE14722 and GSE25906. Additionally, recursive feature elimination was applied to arrive at a further reduced set of pathways. To assess the validity of the pre-eclampsia pathways, a statistically-validated protocol was executed using five data sets including two independent other validation data sets, GSE30186, GSE44711. Quantitative real-time PCR was performed for genes in a panel of potential pre-eclampsia pathways using placentas of 20 women with normal or severe preeclamptic singleton pregnancies (n = 10, respectively). A panel of ten pathways were found to discriminate women with pre-eclampsia from controls with high accuracy. Among these were pathways not previously associated with pre-eclampsia, such as the GABA receptor pathway, as well as pathways that have already been linked to pre-eclampsia, such as the glutathione and CDKN1C pathways. mRNA expression of GABRA3 (GABA receptor pathway), GCLC and GCLM (glutathione metabolic pathway), and CDKN1C was significantly reduced in the preeclamptic placentas. In conclusion, ten accurate and reliable pre-eclampsia pathways were identified based on multiple independent microarray data sets. A pathway-based classification may be a worthwhile approach to elucidate the pathogenesis of pre-eclampsia.

Pregnancy outcomes in liver transplant recipients: A 15‐year single‐center experience

There are an increasing number of reports of pregnancy following liver transplantation, but many questions remain regarding preconception counseling and management of the pregnancy. The aim of this study was to report pregnancy outcomes in women who had undergone liver transplants and to gain insight into these issues.

Simvastatin inhibits oxidative stress via the activation of nuclear factor erythroid 2‐related factor 2 signaling in trophoblast cells

Nuclear factor erythroid 2‐related factor 2 (Nrf2) is a key transcriptional regulator against oxidative stress through the induction of antioxidant and cytoprotective genes, such as heme oxygenase 1 (HO‐1), glutamyl cysteine ligase catalytic (GCLC), and glutamyl cysteine ligase modulatory (GCLM). Nrf2 signaling is disrupted in pre‐eclamptic placentas, although increased oxidative stress is implicated in pre‐eclampsia. The aims of the study were: (i) to investigate the mechanism that underlies the impaired Nrf2 signaling in pre‐eclamptic placentas, and (ii) to examine the potential therapeutic role of statin for pre‐eclampsia.

Alterations of circulating endothelial cell and endothelial progenitor cell counts around the ovulation.

CONTEXT Circulating endothelial cells (CECs) and progenitor cells (CEPs) have been intensively studied as a promising tool for treating ischemic diseases and monitoring cancer treatments, but how the menstrual cycle affects the variation in their counts remains unclear. OBJECTIVE The aims of the study were to determine the influence of the menstrual cycle on the number of CECs and CEPs and to investigate the association of their counts with circulating hormones and angiogenesis-associated factors. DESIGN CEP and CEC counts by flow cytometry and the CellSearch system and circulating factor levels were measured eight times during the menstrual cycle in 18 volunteers. The menstrual cycle was divided into six phases based on hormone concentrations. RESULTS CEP counts peaked in the periovulatory and middle luteal phases with a drop in the early luteal phase. CEC counts showed no significant variation. There were significant correlations between the CEP counts and the serum concentrations of estradiol (E2), LH, and granulocyte colony-stimulating factor (G-CSF) (P < 0.0001, P < 0.0001, and P = 0.01, respectively). The difference in CEP counts between two adjacent phases was significantly correlated with that in E2, LH, G-CSF, and serum vascular endothelial growth factor (P < 0.0001, P < 0.0001, P = 0.02, and P = 0.006, respectively). CONCLUSION CEP counts peaked in the periovulatory and middle luteal phases, with a drop in the early luteal phase, and were correlated with serum E2, LH, and G-CSF concentrations. Consideration of the variation in CEP counts would be important for the clinical application of CEPs.

Magnesium sulphate can prolong pregnancy in patients with severe early-onset preeclampsia

Abstract Objective: To assess whether long-term use of magnesium sulphate prolongs pregnancy in patients with severe early-onset preeclampsia. Methods: Retrospective cohort study included all singleton pregnancies with severe early-onset preeclampsia, expectantly managed in our institution between 2005 and 2013. Obstetric and perinatal outcomes were compared between patients managed using a current protocol that tolerates long-term (over 48 h) use of magnesium sulphate (long-term group, n = 26) and a historical control group (control group, n = 15) that underwent conventional treatment (up to 48 h use of magnesium sulphate). Results: Long-term group showed significant prolongation of pregnancy compared with the control group (9.2 ± 7.9 versus 16.6 ± 9.3 d, log-rank test, p = 0.021), which was also observed in patients with severe preeclampsia occurring before 28 weeks’ gestation (n = 11, 4.5 ± 5.2 versus 13.2 ± 6.8 d, log-rank test, p = 0.035). In contrast to a progressive decrease of platelet count in patients managed without magnesium sulphate, administration of magnesium sulphate for 7 d prevented the decrease of platelet count (p = 0.001). Thirty two percent of patients (13/41) experienced a major complication irrespective of duration of magnesium sulphate use. Conclusions: Long-term use of magnesium sulphate prolonged pregnancy in patients with severe early-onset preeclampsia and can help alleviate progression of preeclampsia.

Endothelial function progressively deteriorates during normal pregnancy

Objective: To elucidate changes in endothelial function throughout the gestational period in normal pregnancy and its relationship with plasma soluble fms-like tyrosine kinase-1 (sFlt-1) levels. Methods: Endothelial function was evaluated by reactive hyperemia index (RHI) using Endo-PAT2000 and plasma sFlt-1 levels were measured simultaneously by ELISA. Results: RHI gradually deteriorated with increasing gestational age. Plasma sFlt-1 levels exhibited a gradual increase at late pregnancy and were inversely correlated with RHI. Conclusion: Maternal endothelial function gradually deteriorates with increasing gestational age and there is an inverse correlation between endothelial function and plasma sFlt-1 levels in normal pregnancy.

‘Tandem balloon tamponade’ for arterial bleeding from the uterine fundus: two case reports

A 34-year-old, gravida 6, para 2 woman had an uneventful prenatal course until 12 weeks of gestation, but she was diagnosed with a missed miscarriage at 15 weeks of gestation. After a dilation and curettage, uterine bleeding persisted and the blood loss reached up to 750 ml despite administration of uterotonics. The patient was therefore transferred to our hospital. Upon admission, her blood pressure was 122/68 mmHg and pulse 52 beats per minute. The uterus was filled with blood clots, and dynamic CT showed extravasation from the uterine fundus in the arterial phase (Figure 1A). Laboratory data were hemoglobin 11.0 g/dL, platelet count 85 10/L, and fibrinogen 550 mg/dL (normal, 200–400 mg/dL). A 100 mL saline-filled 22FR Foley balloon catheter (Medicon, Inc., Osaka, Japan) was initially placed in the uterus, but the bleeding persisted. Transabdominal colour Doppler ultrasound (Voluson , GE Healthcare, Milwaukee, WI) examination confirmed the persistent bleeding site at the fundus, where direct compression by the balloon was hampered by the catheter tip. Thus, a Fuji balloon catheter (Fuji-Metro ; Fuji Latex Co., Ltd., Tokyo, Japan), which has no drainage tip and is similar to a Rusch balloon, was firstly placed in the upper part of the uterus and inflated with 40 mL of normal saline. Subsequently, a 100 mL saline-filled 22FR Foley balloon catheter was placed tandemly (Figure 1B). The cervix was clamped by ring forceps (Figure 1C) with a rather simple modification (Supplementary Figure 1) of our previously reported technique (Kawamura et al. 2013), the cervical clamp method, to facilitate ease of use for the prevention of displacement of intrauterine balloons. The tandem placement of double balloons seemed to apply firm pressure directly on the bleeding site, and the haemorrhage was successfully stopped. The woman required four units of packed red blood cells, six units of fresh frozen plasma, and 10 units of platelets. She was eventually diagnosed as having thrombotic microangiopathy, and was successfully treated with five-day plasma exchange.