Highly rigid H3.1/H3.2-H3K9me3 domains set a barrier for cell fate reprogramming in trophoblast stem cells.

The placenta is a highly evolved, specialized organ in mammals. It differs from other organs in that it functions only for fetal maintenance during gestation. Therefore, there must be intrinsic mechanisms that guarantee its unique functions. To address this question, we comprehensively analyzed epigenomic features of mouse trophoblast stem cells (TSCs). Our genome-wide, high-throughput analyses revealed that the TSC genome contains large-scale (>1-Mb) rigid heterochromatin architectures with a high degree of histone H3.1/3.2-H3K9me3 accumulation, which we termed TSC-defined highly heterochromatinized domains (THDs). Importantly, depletion of THDs by knockdown of CAF1, an H3.1/3.2 chaperone, resulted in down-regulation of TSC markers, such as Cdx2 and Elf5, and up-regulation of the pluripotent marker Oct3/4, indicating that THDs maintain the trophoblastic nature of TSCs. Furthermore, our nuclear transfer technique revealed that THDs are highly resistant to genomic reprogramming. However, when H3K9me3 was removed, the TSC genome was fully reprogrammed, giving rise to the first TSC cloned offspring. Interestingly, THD-like domains are also present in mouse and human placental cells in vivo, but not in other cell types. Thus, THDs are genomic architectures uniquely developed in placental lineage cells, which serve to protect them from fate reprogramming to stably maintain placental function.

CRISPR screening in human trophoblast stem cells reveals both shared and distinct aspects of human and mouse placental development.

The placenta serves as the interface between the mother and fetus, facilitating the exchange of gases and nutrients between their separate blood circulation systems. Trophoblasts in the placenta play a central role in this process. Our current understanding of mammalian trophoblast development relies largely on mouse models. However, given the diversification of mammalian placentas, findings from the mouse placenta cannot be readily extrapolated to other mammalian species, including humans. To fill this knowledge gap, we performed CRISPR knockout screening in human trophoblast stem cells (hTSCs). We targeted genes essential for mouse placental development and identified more than 100 genes as critical regulators in both human hTSCs and mouse placentas. Among them, we further characterized in detail two transcription factors, DLX3 and GCM1, and revealed their essential roles in hTSC differentiation. Moreover, a gene function-based comparison between human and mouse trophoblast subtypes suggests that their relationship may differ significantly from previous assumptions based on tissue localization or cellular function. Notably, our data reveal that hTSCs may not be analogous to mouse TSCs or the extraembryonic ectoderm (ExE) in which in vivo TSCs reside. Instead, hTSCs may be analogous to progenitor cells in the mouse ectoplacental cone and chorion. This finding is consistent with the absence of ExE-like structures during human placental development. Our data not only deepen our understanding of human trophoblast development but also facilitate cross-species comparison of mammalian placentas.

CITED2 is a conserved regulator of the uterine-placental interface.

Establishment of the hemochorial uterine-placental interface requires exodus of trophoblast cells from the placenta and their transformative actions on the uterus, which represent processes critical for a successful pregnancy, but are poorly understood. We examined the involvement of CBP/p300-interacting transactivator with glutamic acid/aspartic acid-rich carboxyl-terminal domain 2 (CITED2) in rat and human trophoblast cell development. The rat and human exhibit deep hemochorial placentation. CITED2 was distinctively expressed in the junctional zone (JZ) and invasive trophoblast cells of the rat. Homozygous Cited2 gene deletion resulted in placental and fetal growth restriction. Small Cited2 null placentas were characterized by disruptions in the JZ, delays in intrauterine trophoblast cell invasion, and compromised plasticity. In the human placentation site, CITED2 was uniquely expressed in the extravillous trophoblast (EVT) cell column and importantly contributed to the development of the EVT cell lineage. We conclude that CITED2 is a conserved regulator of deep hemochorial placentation.

Cartilage tissues regulate systemic aging via ectonucleotide pyrophosphatase/phosphodiesterase 1 in mice.

Aging presents fundamental health concerns worldwide; however, mechanisms underlying how aging is regulated are not fully understood. Here, we show that cartilage regulates aging by controlling phosphate metabolism via ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1). We newly established an Enpp1 reporter mouse, in which an EGFP-luciferase sequence was knocked-in at the Enpp1 gene start codon (Enpp1/EGFP-luciferase), enabling detection of Enpp1 expression in cartilage tissues of resultant mice. We then established a cartilage-specific Enpp1 conditional knockout mouse (Enpp1 cKO) by generating Enpp1 flox mice and crossing them with cartilage-specific type 2 collagen Cre mice. Relative to WT controls, Enpp1 cKO mice exhibited phenotypes resembling human aging, such as short life span, ectopic calcifications, and osteoporosis, as well as significantly lower serum pyrophosphate levels. We also observed significant weight loss and worsening of osteoporosis in Enpp1 cKO mice under phosphate overload conditions, similar to global Enpp1-deficient mice. Aging phenotypes seen in Enpp1 cKO mice under phosphate overload conditions were rescued by a low vitamin D diet, even under high phosphate conditions. These findings suggest overall that cartilage tissue plays an important role in regulating systemic aging via Enpp1.

The multifaceted role of GCM1 during trophoblast differentiation in the human placenta.

Remodeling of the uterine vasculature by invasive extravillous trophoblasts (EVTs) is a critical aspect of human placentation. Insufficient EVT invasion can lead to severe obstetrical complications like preeclampsia, intrauterine growth restriction, and preterm birth. Glial cells missing-1 (GCM1) is a transcription factor that is crucial for proper placentation in mice, and is highly expressed in human syncytiotrophoblast (ST) and EVTs. GCM1 is classically considered a master regulator of ST formation, but little is known about its contribution to the development and function of EVTs. Therefore, in this study we test the hypothesis that GCM1 is a critical regulator of both EVT and ST development and function. We show that GCM1 is highly expressed in human trophoblast stem (TS) cells differentiated into either ST or EVTs. Knockdown of GCM1 in TS cells hindered differentiation into both ST and EVT pathways. When placed in ST media, GCM1-knockdown cells formed small, unstable clusters; when placed in EVT media, cells had altered morphology and transcript profiles resembling cells trapped in an intermediate state between CT and EVT, and invasive capacity through matrix was reduced. RNA sequencing analysis of GCM1-deficient TS cells revealed downregulation of EVT-associated genes and enrichment in transcripts related to WNT signaling, which was linked to decreased expression of the EVT master regulator ASCL2 and the WNT antagonist NOTUM. Our findings reveal an essential role of GCM1 during ST and EVT development, and suggest that GCM1 regulates differentiation of human TS cells into EVTs by inducing expression of ASCL2 and NOTUM.

Intersection of regulatory pathways controlling hemostasis and hemochorial placentation.

Hemochorial placentation is characterized by the development of trophoblast cells specialized to interact with the uterine vascular bed. We utilized trophoblast stem (TS) cell and mutant rat models to investigate regulatory mechanisms controlling trophoblast cell development. TS cell differentiation was characterized by acquisition of transcript signatures indicative of an endothelial cell-like phenotype, which was highlighted by the expression of anticoagulation factors including tissue factor pathway inhibitor (TFPI). TFPI localized to invasive endovascular trophoblast cells of the rat placentation site. Disruption of TFPI in rat TS cells interfered with development of the endothelial cell-like endovascular trophoblast cell phenotype. Similarly, TFPI was expressed in human invasive/extravillous trophoblast (EVT) cells situated within first-trimester human placental tissues and following differentiation of human TS cells. TFPI was required for human TS cell differentiation to EVT cells. We next investigated the physiological relevance of TFPI at the placentation site. Genome-edited global TFPI loss-of-function rat models revealed critical roles for TFPI in embryonic development, resulting in homogeneous midgestation lethality prohibiting analysis of the role of TFPI as a regulator of the late-gestation wave of intrauterine trophoblast cell invasion. In vivo trophoblast-specific TFPI knockdown was compatible with pregnancy but had profound effects at the uterine-placental interface, including restriction of the depth of intrauterine trophoblast cell invasion while leading to the accumulation of natural killer cells and increased fibrin deposition. Collectively, the experimentation implicates TFPI as a conserved regulator of invasive/EVT cell development, uterine spiral artery remodeling, and hemostasis at the maternal-fetal interface.

ASCL2 reciprocally controls key trophoblast lineage decisions during hemochorial placenta development.

Invasive trophoblast cells are critical to spiral artery remodeling in hemochorial placentation. Insufficient trophoblast cell invasion and vascular remodeling can lead to pregnancy disorders including preeclampsia, preterm birth, and intrauterine growth restriction. Previous studies in mice identified achaete-scute homolog 2 (ASCL2) as essential to extraembryonic development. We hypothesized that ASCL2 is a critical and conserved regulator of invasive trophoblast cell lineage development. In contrast to the mouse, the rat possesses deep intrauterine trophoblast cell invasion and spiral artery remodeling similar to human placentation. In this study, we investigated invasive/extravillous trophoblast (EVT) cell differentiation using human trophoblast stem (TS) cells and a loss-of-function mutant Ascl2 rat model. ASCL2 transcripts are expressed in the EVT column and junctional zone, which represent tissue sources of invasive trophoblast progenitor cells within human and rat placentation sites, respectively. Differentiation of human TS cells into EVT cells resulted in significant up-regulation of ASCL2 and several other transcripts indicative of EVT cell differentiation. Disruption of ASCL2 impaired EVT cell differentiation, as indicated by cell morphology and transcript profiles. RNA sequencing analysis of ASCL2-deficient trophoblast cells identified both down-regulation of EVT cell-associated transcripts and up-regulation of syncytiotrophoblast-associated transcripts, indicative of dual activating and repressing functions. ASCL2 deficiency in the rat impacted placental morphogenesis, resulting in junctional zone dysgenesis and failed intrauterine trophoblast cell invasion. ASCL2 acts as a critical and conserved regulator of invasive trophoblast cell lineage development and a modulator of the syncytiotrophoblast lineage.

Maternal lifestyle and nutrient intakes during pregnancy and exclusive breastfeeding in relation to risk factors for breast cancer: The Japan Environment and Children's Study.

Breastfeeding has many benefits for infant growth and maternal health, such as reducing breast cancer risk. However, data on maternal factors influencing breastfeeding are insufficient. To clarify the associations between maternal lifestyle and diet during pregnancy and exclusive breastfeeding (EBF), we conducted a prospective study of pregnant women within the framework of the Japan Environment and Children's Study (a nationwide birth cohort study). Of 97,413 pregnant women recruited between January 2011 and March 2014, 27,775 with a singleton first live birth whose dietary data during pregnancy and lactation data were complete were eligible. Using logistic regression, we evaluated the associations between lifestyle factors including smoking and prepregnancy body mass index and intake of nutrients (macronutrients, isoflavones, and dietary fiber), some of which are known risk factors of breast cancer, and EBF for one month postpartum (initiation of EBF). To investigate the associations of these factors with EBF for 6 months (continuation of EBF), 9582 women who had successfully completed one-month EBF were further followed up. Smoking and prepregnancy obesity were inversely associated with the initiation and continuation of EBF. Intakes of protein, fat, isoflavone, and dietary fiber were positively associated (p trend = 0.0001 for dietary fiber), and carbohydrate intake was inversely associated with the initiation of EBF. Dietary fiber intake was also associated with the continuation of EBF (p trend = 0.048). These findings indicate that maternal lifestyles during pregnancy affect lactation performance. Lifestyle adjustments during pregnancy may have favorable effects on maternal and children's health through successful breastfeeding.

Factors associated with new onset of father-to-infant bonding failure from 1 to 6 months postpartum: an adjunct study of the Japan environment and children's study.

PURPOSE: This study aimed to determine the factors associated with new onset father-to-infant (paternal) bonding failure from 1 to 6 months postpartum. METHODS: This was a prospective birth-cohort study. Paternal bonding failure was evaluated using the Japanese version of the Mother-to-Infant Bonding Scale (MIBS-J) at 1 and 6 months postpartum. For cut-off scores, overall bonding failure, MIBS-J total scores ≥ 5; subscale for lack of affection, MIBS-J_LA scores ≥ 3; and subscale for anger/rejection, MIBS-J_AR scores ≥ 3 were used in this study. Multivariate regression analysis was performed to analyze relative variables. RESULTS: We analyzed 872 fathers. The frequency of new-onset overall bonding failure, lack of affection, and anger/rejection was 5.6%, 4.9%, and 6.3%, respectively. For new-onset overall bonding failure, significant associated factors were paternal childcare leave (adjusted odds ratio [AOR] 3.192; 95% confidence interval [CI] 1.203-8.469), paternal new-onset depression symptoms (AOR 3.181; 95% Cl 1.311-7.716), and maternal new-onset overall bonding failure (AOR 4.595; 95% Cl 1.119-18.866). For new-onset lack of affection, significant associated factors were preterm birth (AOR 4.189; 95% Cl 1.473-11.913) and paternal new-onset depression symptoms (AOR 3.290; 95% Cl 1.294-8.362). For new-onset anger and rejection, significant associated factors were paternal childcare leave (AOR 3.142; 95% Cl 1.138-8.676), paternal new-onset depression symptoms (AOR 2.829; 95% Cl 1.133-7.068), and maternal new-onset anger/rejection (AOR 7.064; 95% Cl 2.300-21.700). CONCLUSIONS: The factors associated with new-onset paternal bonding failure from 1 to 6 months postpartum were paternal childcare leave, preterm birth, paternal postpartum depression symptoms, and maternal bonding failure.

Atypical protein kinase C iota (PKCλ/ι) ensures mammalian development by establishing the maternal-fetal exchange interface.

In utero mammalian development relies on the establishment of the maternal-fetal exchange interface, which ensures transportation of nutrients and gases between the mother and the fetus. This exchange interface is established via development of multinucleated syncytiotrophoblast cells (SynTs) during placentation. In mice, SynTs develop via differentiation of the trophoblast stem cell-like progenitor cells (TSPCs) of the placenta primordium, and in humans, SynTs are developed via differentiation of villous cytotrophoblast (CTB) progenitors. Despite the critical need in pregnancy progression, conserved signaling mechanisms that ensure SynT development are poorly understood. Herein, we show that atypical protein kinase C iota (PKCλ/ι) plays an essential role in establishing the SynT differentiation program in trophoblast progenitors. Loss of PKCλ/ι in the mouse TSPCs abrogates SynT development, leading to embryonic death at approximately embryonic day 9.0 (E9.0). We also show that PKCλ/ι-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. PKCλ/ι is selectively expressed in the first-trimester CTBs of a developing human placenta. Furthermore, loss of PKCλ/ι in CTB-derived human trophoblast stem cells (human TSCs) impairs their SynT differentiation potential both in vitro and after transplantation in immunocompromised mice. Our mechanistic analyses indicate that PKCλ/ι signaling maintains expression of GCM1, GATA2, and PPARγ, which are key transcription factors to instigate SynT differentiation programs in both mouse and human trophoblast progenitors. Our study uncovers a conserved molecular mechanism, in which PKCλ/ι signaling regulates establishment of the maternal-fetal exchange surface by promoting trophoblast progenitor-to-SynT transition during placentation.

Social Capital and Physical Activity among Japanese Pregnant Women: Adjunct Study of Japan Environment and Children's Study in Miyagi Prefecture.

Adequate physical activity during pregnancy is crucial for maternal and fetal health. Although physical activity during pregnancy is restricted, social support and trust may have a favorable influence on physical activity. This study aimed to examine the association between cognitive social capital during pregnancy and prenatal physical activity among Japanese individuals. We also investigated whether social capital has an extended influence during pregnancy on physical activity 1.5 years after delivery. The cognitive social capital of 3,055 pregnant women in their second trimester was measured using nine questions on a self-administered questionnaire. Each cognitive social capital was classified into two or four groups based on their scores. Physical activity during pregnancy was measured using a validated questionnaire in the second trimester and at 1.5 years after delivery. Participants were classified as having adequate physical activity (≥ 150 min/week) or inadequate physical activity (< 150 min/week) based on the physical activity guidelines during pregnancy. After adjusting for confounders, emotional support was positively associated with the prevalence of adequate prenatal physical activity (P for trend = 0.002). Moreover, there was a positive association between emotional support during pregnancy and the prevalence of adequate physical activity 1.5 years after delivery. Among Japanese women, emotional support during pregnancy was associated with a higher prevalence of adequate prenatal physical activity during pregnancy and at 1.5 years after delivery.

Factors associated with postpartum smoking relapse at early postpartum period of Japanese women in the Japan Environmental and Children's Study.

BACKGROUND: Postpartum smoking relapse is a serious public health concern. Previous studies have identified several risk factors for postpartum smoking relapse; however, very little is known about the predictors of early postpartum smoking relapse. This study aimed to determine postpartum smoking relapse status and its associated risk factors at 1 month postpartum among Japanese women. METHODS: Data were obtained from 93,851 mothers with live births in an ongoing birth cohort study, the Japan Environment and Children's Study. Data on smoking status and confounding variables were collected using self-administered questionnaires and medical record transcripts. Self-administered questionnaires were administered during the first trimester, second/third trimester, and 1 month after delivery. A multiple logistic regression analysis was performed. RESULTS: Among the 14,326 mothers who smoked during pregnancy, 10,917 (76.2%) quit smoking during pregnancy. Subsequently, 617 (5.7%) of the mothers who had quit relapsed smoking at 1 month postpartum. Maternal age (≤24, ≥35), maternal education (≤12 years), parity (≥Second), feeding method (Formula milk), partner smoking status during pregnancy (Smoker), number of cigarettes per day before the cessation of smoking (≥11), maternal alcohol consumption at 1-month postpartum (Drinker), postpartum depression (EPDS score ≥9), and spending time at the parents' home after delivery (≥14 days) were associated with smoking relapse. CONCLUSIONS: A certain number of mothers relapsed even 1 month postpartum. Besides mother's alcohol and smoking habit before pregnancy, breastfeeding and partner smoking are important factors in early postpartum smoking relapse in Japan.

Association between whole blood metallic elements concentrations and gestational diabetes mellitus in Japanese women: The Japan environment and Children's study.

BACKGROUND: Exposure to several metallic elements has been suggested as a risk factor for gestational diabetes mellitus (GDM), but inconsistent findings have been reported. This study aimed to examine the association between the maternal whole blood concentration of metallic elements (Hg, Pb, Cd, Mn, and Se) and GDM using the dataset of the Japan Environment and Children's Study (JECS), a nationwide birth cohort study, which was designed to examine the adverse effects of pre/post-natal exposure to hazardous environment. METHODS: The data of 78,964 pregnant women who were participants of JECS were used. Blood samples were collected from the pregnant women at second/third trimester of gestation. We employed logistic regression analysis, quantile g-computation (QGC) and a distributed lag nonlinear model (DLNM) to examine the association between the blood concentration of metallic elements and the risk of GDM. RESULTS: The prevalence of GDM was 2.1%. In the logistic regression analyses, maternal blood Hg was associated with an increased risk of GDM. In QGC analysis, although metallic elements mixtures were not related to an increased risk of GDM, Hg (52.6%) may be the main contributor. According to the results of DLNM, for maternal exposure to Hg, 4.99 ng/g was identified as its susceptible minimum window for elevated risk of GDM. CONCLUSIONS: Our findings highlighted an association between Hg exposure and an increased risk of GDM. Studies of the underlying mechanisms and potential contributing factors, including fish intake, of this association are warranted.

Neurodevelopmental trajectories in children with cleft lip and palate: A longitudinal study based on the Japan Environment and Children's Study.

Cleft lip and/or palate (CL/P), the most prevalent congenital anomaly, is understood to negatively affect a wide range of child development. Since the concept remains controversial, because most published work is from cross-sectional studies, we examined the neurodevelopmental trajectories in participants with CL/P through a longitudinal comparison with the general population during early childhood using data from a nationwide birth cohort study in Japan. The linear mixed models for each domain of the Ages and Stages Questionnaire, third edition (ASQ-3), were used to detect differences in standardised mean scores between groups. The ASQ-3 is a general neurodevelopmental screening tool comprising communication, gross motor, fine motor, problem-solving, and personal-social domains. Participants' neurodevelopment was determined semi-annually from 6 to 36 months of age. The trajectories of standardised mean scores in each domain showed several significant differences between the control and CL/P groups, with the maximum difference at 24 months of age in the communication domain. Indeed, CL/P was associated with significantly lower scores in the communication (coefficient: -3.31, 95% CI: -5.09 to -1.14), problem-solving (coefficient: -3.13, 95% CI: -5.07 to -1.18), and personal-social domains (coefficient: -1.99, 95% CI: -3.87 to -0.11). Trajectories of ASQ-3 scores suggest neurodevelopmental delays in children with CL/P.

The PETTICOAT-Snowshoe Technique Prevents Distal Stent Graft-Induced New Entry in Patients with Aortic Dissection.

PURPOSE: Distal stent graft-induced new entry (SINE) is a serious complication of thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD). The PETTICOAT-snowshoe technique was developed to prevent distal SINE for double-barrel TBAD. Initially, a proximal stent-graft (SG) is deployed, followed by the extension of a bare stent above the celiac artery and deployment of a second SG within the bare stent. This study examined whether the PETTICOAT-snowshoe technique prevents distal SINE. MATERIALS AND METHODS: This was a single-center, retrospective study comparing 2 groups that underwent conventional standard TEVAR between January 2013 and September 2018 and TEVAR using the PETTICOAT-snowshoe technique after October 2018 for double-barrel TBAD. RESULTS: Twenty-seven patients (74% male) underwent standard TEVAR (group A), while another 27 (78% male) underwent the PETTICOAT-snowshoe technique (group B). TEVAR was performed in the chronic phase on 15 patients (55.6%) in group A and on 16 (59.2%) in group B. Aorta-related mortality occurred in 1 patient in group A (3.7%). Oversizing ratios at the distal edge of the SG diameter to the major axis of the true lumen were 25% ± 26% and 25% ± 21% in groups A and B, respectively. During the follow-up period, 5 patients (18.5%) in group A and none in group B (P = 0.02) developed distal SINE. 3 of 5 patients with distal SINE in group A were treated with additional TEVAR, one with thoracoabdominal aortic replacement, and one with conservative observation. The freedom from distal SINE rate was significantly higher in group B than in group A (P = 0.04). CONCLUSIONS: The PETTICOAT-snowshoe technique significantly prevented distal SINE during the mid-term period even with the same distal SG oversizing as conventional standard TEVAR.

Loss of p57KIP2 expression confers resistance to contact inhibition in human androgenetic trophoblast stem cells.

A complete hydatidiform mole (CHM) is androgenetic in origin and characterized by enhanced trophoblastic proliferation and the absence of fetal tissue. In 15 to 20% of cases, CHMs are followed by malignant gestational trophoblastic neoplasms including choriocarcinoma. Aberrant genomic imprinting may be responsible for trophoblast hypertrophy in CHMs, but the detailed mechanisms are still elusive, partly due to the lack of suitable animal or in vitro models. We recently developed a culture system of human trophoblast stem (TS) cells. In this study, we apply this system to CHMs for a better understanding of their molecular pathology. CHM-derived TS cells, designated as TSmole cells, are morphologically similar to biparental TS (TSbip) cells and express TS-specific markers such as GATA3, KRT7, and TFAP2C. Interestingly, TSmole cells have a growth advantage over TSbip cells only after they reach confluence. We found that p57KIP2, a maternally expressed gene encoding a cyclin-dependent kinase inhibitor, is strongly induced by increased cell density in TSbip cells, but not in TSmole cells. Knockout and overexpression studies suggest that loss of p57KIP2 expression would be the major cause of the reduced sensitivity to contact inhibition in CHMs. Our findings shed light on the molecular mechanism underlying the pathogenesis of CHMs and could have broad implications in tumorigenesis beyond CHMs because silencing of p57KIP2 is frequently observed in a variety of human tumors.

Prospective association between maternal bonding disorders and child toothbrushing frequency: A cross-sectional study of the Japan Environment and Children's Study.

BACKGROUND: Daily toothbrushing prevents early childhood caries, but reinforcement depends on facilitative parenting behaviours. Mother-to-infant bonding, the maternal affection towards the infant, is an environmental factor that strongly influences parenting. AIM: This study examined the association between maternal bonding and children's daily toothbrushing frequency. DESIGN: The sample consisted of 83 954 mother-infant pairs at two years postpartum, derived from the initial sample of JECS (cohort study), which included 104 062 foetuses. Maternal bonding disorders were assessed using the Mother-to-Infant Bonding Scale (MIBS). After multiple imputation for missing data, a multinomial logistic regression analysis was conducted with adjustments for several maternal (eg, age at delivery) and child-related (eg, self-performed toothbrushing) variables. RESULTS: The odds ratio (95% confidence interval) for the association of maternal bonding disorders with the low (once per day) and the very low child toothbrushing frequency (<1 per day) was 1.12 (1.07-1.17) and 1.23 (0.91-1.66), respectively, after covariate adjustments. Furthermore, the univariate general linear model showed that the mean MIBS scores significantly decreased as the daily child toothbrushing frequency increased. CONCLUSIONS: The prevalence of maternal bonding disorders at one year postpartum was prospectively associated with a lower frequency of child toothbrushing at two years of age.

Genomic imprinting in human placentation.

Background: Genomic imprinting (GI) is a mammalian-specific epigenetic phenomenon that has been implicated in the evolution of the placenta in mammals. Methods: Embryo transfer procedures and trophoblast stem (TS) cells were used to re-examine mouse placenta-specific GI genes. For the analysis of human GI genes, cytotrophoblast cells isolated from human placental tissues were used. Using human TS cells, the biological roles of human GI genes were examined. Main findings: (1) Many previously identified mouse GI genes were likely to be falsely identified due to contaminating maternal cells. (2) Human placenta-specific GI genes were comprehensively determined, highlighting incomplete erasure of germline DNA methylation in the human placenta. (3) Human TS cells retained normal GI patterns. (4) Complete hydatidiform mole-derived TS cells were characterized by aberrant GI and enhanced trophoblastic proliferation. The maternally expressed imprinted gene p57KIP2 may be responsible for the enhanced proliferation. (5) The primate-specific microRNA cluster on chromosome 19, which is a placenta-specific GI gene, is essential for self-renewal and differentiation of human TS cells. Conclusion: Genomic imprinting plays diverse and important roles in human placentation. Experimental analyses using TS cells suggest that the GI maintenance is necessary for normal placental development in humans.

The delivery of a placenta/fetus with high gonadal steroid production contributes to postpartum depressive symptoms.

BACKGROUND: A correlation between gonadal steroids and depressive symptoms during the perinatal period has long been suggested; however, the underlying mechanism for this relationship remains unclear. METHODS: This study was designed to examine the correlation between gonadal steroid concentrations of umbilical cord blood and postpartum depressive symptoms as well as longitudinal alterations in maternal plasma gonadal steroid concentrations among 204 perinatal women. The levels of postpartum depressive state at 1 month postpartum were evaluated using the Edinburgh Postnatal Depression Scale. RESULTS: Umbilical progesterone, estradiol, and testosterone levels were significantly higher in infants delivered by depressed mothers (870.7 ± 281.7 ng/ml, 8607.7 ± 4354.6 pg/ml, and 2.5 ± 0.9 ng/ml, respectively) than those delivered by nondepressed mothers (741.3 ± 324.0 ng/ml, 5221.9 ± 3416.3 pg/ml, and 2.1 ± 0.6 ng/ml, p < .01, p < .05, and p < .05, respectively). Postpartum plasma progesterone levels of depressed mothers (3.5 ± 3.1 ng/ml) measured in the early postpartum period were significantly lower than those of nondepressed mothers (9.1 ± 9.7 ng/ml, p < .01). The decrease in progesterone from mid-pregnancy to the early postpartum period was significantly higher in depressed mothers than in nondepressed mothers. Subgroup analyses specific to primiparas or multiparas indicated that a significant drop of progesterone was seen only in primiparas. CONCLUSION: The current study suggests that the delivery of a placenta/fetus with high gonadal steroid production may cause a wider range of fluctuations in maternal plasma gonadal steroid concentrations, which may be concurrent with postpartum depressive symptoms.

The prevalence of psychological distress during pregnancy in Miyagi Prefecture for 3 years after the Great Eas t Japan Earthquake.

BACKGROUND: To examine changes in psychological distress prevalence among pregnant women in Miyagi Prefecture, which was directly affected by the Great East Japan Earthquake and tsunami, and compare it with the other, less damaged areas of Japan. METHODS: This study was conducted in conjunction with the Japan Environment and Children`s Study. We examined 76,152 pregnant women including 8270 in Miyagi Regional Center and 67,882 in 13 other regional centers from the all-birth fixed data of the Japan Environment and Children's Study. We then compared the prevalence and risk of distress in women in Miyagi Regional Center and women in the 13 regional centers for 3 years after the disaster. RESULTS: Women in the Miyagi Regional Center suffered more psychological distress than those in the 13 regional centers: OR 1.38 (95% CI, 1.03-1.87) to 1.92 (95% CI, 1.42-2.60). Additionally, women in the inland area had a consistently higher prevalence of psychological distress compared to those from the 13 regional centers: OR 1.67 (95% CI, 1.18-2.38) to 2.19 (95% CI, 1.60-2.99). CONCLUSIONS: The lack of pre-disaster data in the Japan Environment and Children's Study made it impossible to compare the incidence of psychological distress before and after the March 2011 Great East Japan Earthquake. However, 3 years after the Great East Japan Earthquake, the prevalence of pregnant women with psychological distress did not improve in Miyagi Regional Center. Further, the prevalence of mental illness in inland areas was consistently higher than that in the 13 regional centers after the disaster.