A 35-year-old primigravida with a history of adenomyosis enucleation was diagnosed with abnormal fetal position at 25 weeks of gestation. The patient presented with normal vital signs and no symptoms. A cardiotocogram and transabdominal ultrasound revealed a healthy fetus, normal amniotic fluid volume, and no intra-abdominal bleeding. Pelvic magnetic resonance imaging (MRI) indicated a ruptured muscular layer of the uterine fundus, with the fetus completely prolapsed into the abdominal cavity. An emergency cesarean section was performed, during which the fetus was found wrapped within the amniotic membrane in the abdominal cavity. The uterus exhibited extensive tearing along the line of the previous surgical scar; however, no hemorrhage was observed. In this case, despite uterine rupture, blood flow through the umbilical cord from the placenta in the uterus resulted in the survival of the fetus. In addition, MRI was essential in determining the appropriate timing to save the fetus.
AIM:To evaluate the relationship between long-term antenatal magnesium sulfate (MgSO4 ) administration and neonatal bone mineralization. METHODS:Infants born at 28-33 weeks of gestation (n = 163) were divided into three groups: long-term Mg administration group (infants received antenatal MgSO4 for ≥40 days), short-term Mg administration group (infants received antenatal MgSO4 for <40 days), and non-Mg group. Serum calcium, phosphorus, Mg, and alkaline phosphatase were measured weekly up to 1 month of age, and the bone speed of sound (SOS) values were measured using quantitative ultrasound (QUS) at 1 week and 1 month after birth. RESULTS:In the long-term Mg administration group, the serum calcium values were significantly lower, and the serum phosphorus, Mg, and alkaline phosphatase values were significantly higher than those in the non-Mg group at birth. Although these biochemical differences disappeared around the age of 2 weeks, the SOS values of the long-term Mg administration group were significantly lower than those of the non-Mg group both at 1 week and 1 month after birth (p = 0.02 and <0.001, respectively). When less than 10th percentile of SOS values at 1 month after birth in the non-Mg group was defined as poor bone mineralization, the cut-off value for the duration of antenatal MgSO4 administration was 67 days. CONCLUSIONS:Long-term antenatal MgSO4 administration affects bone mineralization during the early neonatal period, but the clinically acceptable duration of the administration based on its effects of bone mineralization assessed with QUS might be longer than a few weeks.
Aggrephagy is defined as the selective degradation of aggregated proteins by autophagosomes. Protein aggregation in organs and cells has been highlighted as a cause of multiple diseases, including neurodegenerative diseases, cardiac failure, and renal failure. Aggregates could pose a hazard for cell survival. Cells exhibit three main mechanisms against the accumulation of aggregates: protein refolding by upregulation of chaperones, reduction of protein overload by translational inhibition, and protein degradation by the ubiquitin–proteasome and autophagy–lysosome systems. Deletion of autophagy-related genes reportedly contributes to intracellular protein aggregation in vivo. Some proteins recognized in aggregates in preeclamptic placentas include those involved in neurodegenerative diseases. As aggregates are derived both intracellularly and extracellularly, special endocytosis for extracellular aggregates also employs the autophagy machinery. In this review, we discuss how the deficiency of aggrephagy and/or macroautophagy leads to poor placentation, resulting in preeclampsia or fetal growth restriction.
Cytotrophoblasts differentiate in two directions during early placentation: syncytiotrophoblasts (STBs) and extravillous trophoblasts (EVTs). STBs face maternal immune cells in placentas, and EVTs, which invade the decidua and uterine myometrium, face the cells in the uterus. This situation, in which trophoblasts come into contact with maternal immune cells, is known as the maternal-fetal interface. Despite fetuses and fetus-derived trophoblast cells being of the semi-allogeneic conceptus, fetuses and placentas are not rejected by the maternal immune system because of maternal-fetal tolerance. The acquired tolerance develops during normal placentation, resulting in normal fetal development in humans. In this review, we introduce placental development from the viewpoint of molecular biology. In addition, we discuss how the disruption of placental development could lead to complications in pregnancy, such as hypertensive disorder of pregnancy, fetal growth restriction, or miscarriage.
The coupled repressilators, as a special case of cyclic genetic regulatory networks, can be used to adjust oscillations at the cellular level, and hence it have received extensive attention from many scholars. This paper addresses the problem of global exponential stability analysis for nonnegative equilibrium points of a class of coupled repressilator models with multiple time-varying delays. Sufficient conditions are investigated to guarantee that the considered model has a unique nonnegative equilibrium point which is globally exponentially stable. The obtained criteria are composed of several simple linear inequalities that are only related to the model parameters, so they can be easily verified by using the standard software tools. The results of two illustrative examples present the effectiveness of the proposed approach.
Hypertensive disorders of pregnancy, including preeclampsia, directly affect maternal and perinatal morbidity and mortality. As the pathophysiology of preeclampsia is multi-factorial and has been studied using different approaches, we have demonstrated that impaired autophagy is an intertwined risk factor for preeclampsia. This concept has been verified in both in vitro and in vivo experiments. Autophagy is primarily involved in maintaining cellular homeostasis, and in immune regulation, longevity, cytokines secretion and a variety of other biological functions. Here, we review the role of autophagy in normal embryogenesis and placentation. Once placental autophagy is impaired by metabolic stress such as hypoxia, endoplasmic reticulum stress or starvation, placental development could be disrupted, resulting in functional maladaptations at the maternal-fetal interface. These malfunctions may result in fetal growth restriction or preeclampsia.
Placental homeostasis is directly linked to fetal well-being and normal fetal growth. Placentas are sensitive to various environmental stressors, including hypoxia, endoplasmic reticulum stress, and oxidative stress. Once placental homeostasis is disrupted, the placenta may rebel against the mother and fetus. Autophagy is an evolutionally conservative mechanism for the maintenance of cellular and organic homeostasis. Evidence suggests that autophagy plays a crucial role throughout pregnancy, including fertilization, placentation, and delivery in human and mouse models. This study reviews the available literature discussing the role of autophagy in preeclampsia.
Nanoparticles are widely used in commodities, and pregnant women are inevitably exposed to these particles. The placenta protects the growing fetus from foreign or toxic materials, and provides energy and oxygen. Here we report that autophagy, a cellular mechanism to maintain homeostasis, engulfs platinum nanoparticles (nPt) to reduce their cytotoxicity in trophoblasts. Autophagy was activated by nPt in extravillous trophoblast (EVT) cell lines, and EVT functions, such as invasion and vascular remodeling, and proliferation were inhibited by nPt. These inhibitory effects by nPt were augmented in autophagy-deficient cells. Regarding the dynamic state of nPt, analysis using ICP-MS demonstrated a higher accumulation of nPt in the autophagosome-rich than the cytoplasmic fraction in autophagy-normal cells. Meanwhile, there were more nPt in the nuclei of autophagy-deficient cells, resulting in greater DNA damage at a lower concentration of nPt. Thus, we found a new protective mechanism against the cytotoxicity of nPt in human trophoblasts.
Pregnancy is a stress factor culminating into mild endoplasmic reticulum (ER) stress, which is necessary for placental development. However, excessive or chronic ER stress in pre-eclamptic placentas leads to placental dysfunction. The precise mechanisms through which excessive ER stress impacts trophoblasts are not well understood. Here, we showed that ER stress reduces the number of lysosomes, resulting in inhibition of autophagic flux in trophoblast cells. ER stress also disrupted the translocation of lysosomes to the surface of trophoblast cells, and inhibited lysosomal exocytosis, whereby the secretion of lysosomal-associated membrane protein 1 (LAMP1) into culture media was significantly attenuated. In addition, we found that serum LAMP1 and beta-galactosidase levels were significantly decreased in pre-eclampsia patients compared to normal pregnant women, potentially indicating lysosomal dysfunction through ER stress in pre-eclamptic placentas. Thus, we demonstrated that excessive ER stress essentially disrupts homeostasis in trophoblasts in conjunction with autophagy inhibition by lysosomal impairment.
Autophagy is an evolutionarily conserved process in eukaryotes to maintain cellular homeostasis under environmental stress. Intracellular control is exerted to produce energy or maintain intracellular protein quality controls. Autophagy plays an important role in embryogenesis, implantation, and maintenance of pregnancy. This role includes supporting extravillous trophoblasts (EVTs) that invade the decidua (endometrium) until the first third of uterine myometrium and migrate along the lumina of spiral arterioles under hypoxic and low-nutrient conditions in early pregnancy. In addition, autophagy inhibition has been linked to poor placentation—a feature of preeclamptic placentas—in a placenta-specific autophagy knockout mouse model. Studies of autophagy in human placentas have revealed controversial results, especially with regard to preeclampsia and gestational diabetes mellitus (GDM). Without precise estimation of autophagy flux, wrong interpretation would lead to fixed tissues. This paper presents a review of the role of autophagy in pregnancy and elaborates on the interpretation of autophagy in human placental tissues.
Autophagy is an evolutionarily conserved process in eukaryotes by which cytoplasmic cargo sequestered inside double-membrane vesicles is delivered to the lysosome for degradation. Recently, there is increasing evidence that modulating autophagy accumulates during pregnancy. In early pregnancy, trophoblasts and the fetus experience hypoxic and low-nutrient conditions; nevertheless, extravillous trophoblasts (EVTs) invade the uterine myometrium up to one third of its depth and migrate along the lumina of spiral arterioles, replacing the maternal endothelial lining. An enhancement of autophagy induced by physiological hypoxia occurs during the invasion and vascular remodeling in EVTs. However, soluble endoglin, which is increased in sera in preeclamptic cases, suppresses EVT invasion or vascular remodeling by inhibiting autophagy in vivo. In addition, a substance selectively degraded by autophagy, p62/SQSTM1, accumulates in EVT cells in preeclamptic placental biopsy samples showing impaired autophagy in vivo. On the other hand, there are some reports about autophagy activation in preeclamptic placentas. Though changes in autophagy may affect the fates of mothers and babies, controversy remains for the evaluation of autophagy status in preeclampsia. In this chapter, we will introduce the role of autophagy in embryogenesis, implantation, and maintaining pregnancy and discuss the autophagy status in preeclampsia.
Recent advances in nanotechnology have led to the development of nanoparticles with innovative functions in various fields. However, the biological effects of nanoparticles-particularly those on the fetus-need to be investigated in detail, because several previous studies have shown that various nanoparticles induce pregnancy complications in mice. In this regard, our previous findings in mice suggested that the increase in peripheral neutrophil count induced by treatment with silica nanoparticles with a diameter of 70 nm (nSP70) may play a role in the associated pregnancy complications. Therefore, here, we sought to define the role of neutrophils in nSP70-induced pregnancy complications. The peripheral neutrophil count in pregnant BALB/c mice at 24 h after treatment with nSP70 was significantly higher than in saline-treated mice. In addition, maternal body weight, uterine weight, and the number of fetuses in nSP70-treated mice pretreated with anti-antibodies, which deplete neutrophils, were significantly lower than those in nSP70-treated mice pretreated with phosphate-buffered saline or isotype-matched control antibodies. Histology revealed that neutrophil depletion increased nSP70-induced placental damage from the decidua through the spongiotrophoblast layer and narrowed spiral arteries in the placentae. In addition, depletion of neutrophils augmented nSP70-induced cytotoxicity to fetal vessels, which were covered with endothelium. The rate of apoptotic cell death was significantly higher in the placentae of anti-nSP70-treated mice than in those from mice pretreated with isotype-matched control antibodies. Therefore, impairment of placental vessels and apoptotic cell death due to nSP70 exposure is exacerbated in the placentae of nSP70-treated mice pretreated with anti-antibodies. Depletion of neutrophils worsens nSP70-induced pregnancy complications in mice; this exacerbation was due to enhanced impairment of placental vessels and increased apoptotic cell death in maternal placentae. Our results provide basic information regarding the mechanism underlying silica-nanoparticle-induced pregnancy complications.
妊娠高血圧腎症(Preeclampsia, 以下PE)はPlacenta-mediated pregnancy complications(胎盤関連妊娠合併症)の一つであり、その他に子宮内胎児発育遅延(Fetal growth restriction、以下FGR)、死産、常位胎盤早期剝離などが含まれる。つまり、重篤な周産期合併症の多くは胎盤形成と密接に関係していることを意味している。これまで、PEの病態形成として2ステップセオリーが提唱され、第一ステップとしての胎盤形成不全、第二ステップとしての血管内皮障害が起こるとされてきた[1]。これまで我々は、細胞自身がもつオートファジー(自食作用)という機構に注目し、EVT機能(浸潤および血管リモデリング)抑制がオートファジー抑制に関与することを明らかにしてきた[2]。さらに、近年、胎盤特異的Atg7欠損マウスを作成し、そのマウスでは胎盤形成不全及び母獣血圧の上昇を認めることも報告した[3]。一方で同マウスは、蛋白尿および胎児発育不全を合併しないことも明らかとなった。つまり、胎盤におけるオートファジー抑制はPEの第一ステップと強く関与し、第二ステップには寄与しないことも分かってきた。加えて、神経変性疾患にみられる凝集蛋白蓄積は、オートファジー抑制を介してPE胎盤の病態形成にも関与することが示唆されている。そこで、PEにおけるオートファジーと凝集蛋白蓄積について、本編で概説する。
Preeclampsia is a serious disorder of human pregnancy occurring after 20 weeks of gestation. It can be divided into subtypes of early onset (<34 weeks of gestation) and late onset (>34 weeks). Presymptomatic detection to identify those at high risk is important for managing this disease. HtrA3, a serine protease with high expression in the developing placenta, exists in long (HtrA3-L) and short (HtrA3-S) isoforms. They are identical, except HtrA3-S lacks the C-terminal PDZ domain. We have previously shown by Western blot analysis that serum HtrA3 levels at the end of the first trimester are significantly higher in women who later develop preeclampsia than in controls. In this study, using highly specific HtrA3 monoclonal antibodies, we established and fully validated two enzyme-linked immunosorbent assays to detect both HtrA3 isoforms together (HtrA3-T) and HtrA3-L alone in the human serum. We then determined serum HtrA3 at 11 to 13 weeks of gestation in a cohort of singleton pregnancies that proceeded without complications or developed preeclampsia in the third trimester. Compared with controls, those who developed late-onset preeclampsia had significantly higher levels of HtrA3-L, whereas those who developed early-onset preeclampsia had significantly lower ratios of HtrA3-L/HtrA3-T. These data support a potential utility of these HtrA3 ELISAs for early detection of preeclampsia.