Gen Ishikawa

Human Villous Trophoblasts Express and Secrete Placenta-Specific MicroRNAs into Maternal Circulation via Exosomes

In this study, we performed small RNA library sequencing using human placental tissues to identify placenta-specific miRNAs. We also tested the hypothesis that human chorionic villi could secrete miRNAs extracellularly via exosomes, which in turn enter into maternal circulation. By small RNA library sequencing, most placenta-specific miRNAs (e.g., MIR517A) were linked to a miRNA cluster on chromosome 19. The miRNA cluster genes were differentially expressed in placental development. Subsequent validation by real-time PCR and in situ hybridization revealed that villous trophoblasts express placenta-specific miRNAs. The analysis of small RNA libraries from the blood plasma showed that the placenta-specific miRNAs are abundant in the plasma of pregnant women. By real-time PCR, we confirmed the rapid clearance of the placenta-specific miRNAs from the plasma after delivery, indicating that such miRNAs enter into maternal circulation. By using the trophoblast cell line BeWo in culture, we demonstrated that miRNAs are indeed extracellularly released via exosomes. Taken together, our findings suggest that miRNAs are exported from the human placental syncytiotrophoblast into maternal circulation, where they could target maternal tissues. Finally, to address the biological functions of placenta-specific miRNAs, we performed a proteome analysis of BeWo cells transfected with MIR517A. Bioinformatic analysis suggests that this miRNA is possibly involved in tumor necrosis factor-mediated signaling. Our data provide important insights into miRNA biology of the human placenta.

Hydroxysteroid (17-β) Dehydrogenase 1 Is Dysregulated by Mir-210 and Mir-518c That Are Aberrantly Expressed in Preeclamptic Placentas: A Novel Marker for Predicting Preeclampsia

In this study, to search for novel preeclampsia (PE) biomarkers, we focused on microRNA expression and function in the human placenta complicated with PE. By comprehensive analyses of microRNA expression, we identified 22 microRNAs significantly upregulated in preeclamptic placentas, 5 of which were predicted in silico to commonly target the mRNA encoding hydroxysteroid (17-&bgr;) dehydrogenase 1 (HSD17B1), a steroidogenetic enzyme expressed predominantly in the placenta. In vivo HSD17B1 expression, at both the mRNA and protein levels, was significantly decreased in preeclamptic placentas. Of these microRNAs, miR-210 and miR-518c were experimentally validated to target HSD17B1 by luciferase assay, real-time PCR, and ELISA. Furthermore, we found that plasma HSD17B1 protein levels in preeclamptic pregnant women reflected the decrease of its placental expression. Moreover, a prospective cohort study of plasma HSD17B1 revealed a significant reduction of plasma HSD17B1 levels in pregnant women at 20 to 23 and 27 to 30 weeks of gestation before PE onset compared with those with normal pregnancies. The sensitivities/specificities for predicting PE at 20 to 23 and 27 to 30 weeks of gestation were 0.75/0.67 (cutoff value=21.9 ng/mL) and 0.88/0.51 (cutoff value=30.5 ng/mL), and the odds ratios were 6.09 (95% CI: 2.35–15.77) and 7.83 (95% CI: 1.70–36.14), respectively. We conclude that HSD17B1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placenta and that reducing plasma level of HSD17B1 precedes the onset of PE and is a potential prognostic factor for PE.

The Cytotrophoblast Layer of Human Chorionic Villi Becomes Thinner but Maintains Its Structural Integrity During Gestation

Abstract Chorionic villi in the human placenta serve as essential structures in fetomaternal exchanges. According to the embryology and placentology literature, during the first trimester, the cytotrophoblast (CTB) layer that is subjacent to the syncytiotrophoblast (STB) and supported by a basal lamina is nearly complete, but later, it becomes discontinuous. In the present study, we investigated the structural integrity of the CTB layer in the normal villous tree by advanced microscopy techniques using an antibody to hepatocyte growth factor (HGF) activator inhibitor type 1 (SPINT1), a potent inhibitor of HGF activators expressed exclusively on villous CTB. In full-term placenta, the cell surface of the CTB layer was spread over the basal lamina but was not interrupted. Morphometric analysis showed that throughout the villous tree, 80% of the continuity of the CTB layer of full-term placenta and 90% of that of first-trimester placenta were preserved. Gestation was accompanied by unique structural change in the basal domain of the trophoblast layer. The initially cuboidal-shaped CTB cells were transformed to flat cells with many cellular processes that, together with those of the adjacent STB, eventually covered the trophoblast basal lamina in a complex network of interdigitations. In addition, the expression levels of SPINT1, ST14, HGF, and MET mRNAs in the villous tree increased over the course of gestation. These results suggest that the structural integrity of the SPINT1-positive CTB layer may play an important role in villous differentiation and in maintenance of the villous tree via the HGF signaling system during gestation.

Iatrogenic monoamniotic twin gestation with progressive twin-twin transfusion syndrome.

Objective: Intentional puncture of the membrane has been reported to be a promising new method for the management of twin-twin transfusion syndrome. Case Report: Treatment of twin-twin transfusion syndrome with serial amniocenteses resulted in unintentional puncture of the dividing membrane at 24 weeks of gestation. Fetal growth discordance increased, and twin-twin transfusion did not improve following the puncture. Intrauterine death of both fetuses at 27 weeks of gestation occurred. Conclusion: Amniotic septostomy for the treatment of twin-twin transfusion sydnrome should be performed with serious consideration.

B-Cell-Type Malignant Lymphoma with Placental Involvement

We present here a case of B‐cell‐type mediastinal malignant lymphoma during pregnancy complicated by placental involvement. In this case, some nodular high‐echo patterns were recognized in the placenta by ultrasonography. A cesarean section and resection of the mediastinal tumor were performed at 33 weeks and 6 days of gestation due to the deterioration of the dyspnea. A female infant weighing 1,868 g was delivered and she is now a healthy 2‐year‐old. The mother, however, died of the disease 1 month after surgery, due to progression of the tumor. The placenta showed numerous white firm nodules varying from 3 mm to 3 cm in diameter. The pathologic findings of both the mediastinal tumor and the placenta indicated primary mediastinal (thymic) B‐cell lymphoma.

Umbilical Venous Pulsation Indicating Tight Cord Entanglement in Monoamniotic Twin Pregnancy

Increased risks in monoamniotic twin pregnancies are due primarily to cord entanglement,1 leading to compression and fetal asphyxia. Unfortunately, the prevalence of this condition has been reported to be 40 to 70% in monoamniotic twin pregnancies.1,2 Therefore, when cord entanglement is diagnosed, we must be able to predict whether or not fetal asphyxiation will occur. In singleton pregnancies, umbilical venous pulsations have been observed in abnormal fetuses with heart failure or in normal fetuses using pulsations of the umbilical arteries.3 We present a case of monoamniotic twin pregnancy in which umbilical venous pulsations suggested tight cord entanglement leading to progressive preloading of the fetal heart.

Analgesia after upper abdominal surgery with extradural buprenorphine with lidocaine

PurposeTo determine whetherthe continuous low thoracic extradural administration of the same dose of lidocaine at low concentration with a high infusion rate or at high concentration with a low infusion rate in combination with a fixed dose of buprenorphine (0.4 ing·day−1) modifies postoperative pain relief.MethodsTwenty-eight patients undergoing elective upper abdominal surgery were randomly allocated to one of two groups to receive lidocaine 2% — buprenorphine at a rate of 6.3 ml· hr−1 (2% group, n = 13) or lidocaine 6% — buprenorphine at a rate of 2.1 ml· hr−1 (6% group, n = 15). During suture of the peritoneum, mepivacaine 2% (8 ml) with 0.1 mg (0.5 ml) buprenorphine was infused extradurally. After extubation, the continuous extradural infusion was initiated. Patients were assessed for the level of analgesia with the 10 cm VAS score at rest and with the Prince Henry Pain Scale (PHPS) at 3, 6, 9, 12, 18, and 24 hr postoperatively.ResultsThe visual analogue scale (VAS) scores at rest did not differ between the two groups except at 18 hr after surgery. The Prince Henry Pain Scale (PHPS) scores were not different between the two groups post-operatively.ConclusionThere was no difference in analgesia produced by the continuous extradural infusion of lidocaine 2% — buprenorphine at a rate of 6.3 ml· hr−1 and that of lidocaine 6% — buprenorphine at a rate of 2.1 ml· hr−1 following upper abdominal surgery.RésuméObjectifDéterminer si la perfusion épidurale thoracique basse d’une même dose de lidocaïne à basse concentration avec un débit élevé de perfusion ou une haute concentration avec un débit faible de perfusion en association avec une dose fixe de buprénorphine (0,4 mg · j−1) modifie le soulagement de la douleur.MéthodesVingt-huit patients programmés pour une chirurgie non urgente de l’étage supérieur de l’abdomen participaient à l’étude. Ils étaient répartis aléatoirement en deux groupes dont l’un recevait lidocaïne 2% —buprénorphine à la vitesse de 6,3 ml· h−1 (groupe 2% = 13) l’autre lidocaïne 6% — buprénorphine (groupe 6% = 15) à la vitesse de 2,1 ml· h−1. Au moment de la fermeture du péritoine, on injectait en épidural de la mépivacaïne à 2% (8 ml) avec 0,1 mg (0,5) de buprénorphine. Après l’extubation, on débutait la perfusion épidurale continue. Le niveau d’analgésie des patients était évalué à 3, 6, 9, 12, 18 et 24 heures en post-opératoire au moyen de l’EVA de 10 cm pour la douleur au repos et avec le Prince Henry Pain Scale (PHPS).RésultatsLes scores sur l’ÉVA au repos ne différaient pas entre les groupes excepté 18 hres après l’intervention. Le PHPS n’était différent en aucun moment de la période postopératoireConclusionAprès une chirurgie abdominale, l’analgésie produite par la perfusion épidurale de lidocaïne 2% — buprénorphine au débit de 6,3 ml·h−1 était la même que celle produite par la lidocaïne 6% — buprénorphine au débit de 2,1 ml·h−1.

Analgesia after upper abdominal surgery using extradural administration of a fixed dose of buprenorphine in combination with lignocaine given at two infusion rates: A comparative study

Background: Extradural administration of combinations of local anaesthetics and opioids are frequently employed for postoperative pain relief. There is a scarcity of data on the analgesic effects of variations of the dose of local anaesthetic drug admixed to a fixed dose of opioid.

Glibenclamide inhibits NLRP3 inflammasome-mediated IL-1β secretion in human trophoblasts

Infection-associated pregnancy complications cause premature delivery. Caspase-1 is involved in the maturation of interleukin (IL)-1β, which is activated by the NLRP3 inflammasome. To characterize the significance of the NLRP3 inflammasome pathway in the placenta, the effects of activators and inhibitors on NLRP3-related molecules were examined using isolated primary trophoblasts. Caspase-1 and IL-1β mRNA expression was markedly increased in response to lipopolysaccharide (LPS), a toll-like receptor (TLR)4 ligand. Treatment with the potassium ionophore nigericin significantly increased the level of activated caspase-1. Treatment with either LPS or nigericin stimulated IL-1β secretion, whereas pretreatment with the ATP-sensitive K+ channel inhibitor glibenclamide, the Rho-associated coiled-coil kinase inhibitor Y-27632, or a caspase-1 inhibitor significantly decreased nigericin-induced IL-1β secretion. In addition, dibutyryl-cAMP, which induces trophoblast differentiation, decreased expression of NLRP3, caspase-1, and IL-1β. These findings suggest that trophoblasts can secrete IL-1β through the NLRP3/caspase-1 pathway, which is suppressed by glibenclamide, and that the TLR4-mediated NLRP3 inflammasome pathway is more likely to be stimulated in undifferentiated than differentiated trophoblasts. Our data support the hypothesis that inhibition of the NLRP3 inflammasome can suppress placental inflammation-associated disorders.

Fetal Circulatory Responses to Maternal Blood Loss

We examined the fetal circulatory responses to maternal blood loss in pregnant women during the third trimester. Seven healthy women with placenta previa and singleton pregnancies underwent phlebotomies in an autologous donation program. Four hundred milliliters of blood was collected within 15 min at 34 and 35 weeks of gestation. Continuous electric recordings of fetal heart rate were performed during the first blood collection, and the maternal uterine artery (UtA), umbilical artery (UmA) and fetal middle cerebral artery (MCA) Doppler velocity waveforms were recorded before, immediately after and 24 h after the second collection in each patient. The average fetal heart rate, maternal UtA and UmA pulsatility indices did not change measurably during or after maternal blood collections. However, the average fetal MCA pulsatility index decreased significantly 24 h after maternal blood loss. The observation of a decrease in fetal MCA pulsatility index may indicate delayed fetal asphyxia following mild maternal hemorrhage.