Biology subjects

Okae, H.

Publications and source records attributed to Okae, H..

8 recordsLinked to original sources

bioRxiv2025

PPARG directs trophoblast cell fate and establishment of the uterine-placental interface

The expansion and differentiation of trophoblast stem (TS) cells are critical for defining fundamental properties of the placenta. Specialized trophoblast cells exit the placenta and enter and transform the uterus, including restructuring uterine spiral arteries. In the human these cells are named extravillous trophoblast (EVT) cells, whereas in the rat they are termed invasive trophoblast cells. Mechanisms governing invasive trophoblast cell differentiation remain poorly understood. We investigated peroxisome proliferator-activated receptor gamma (PPARG) as a potential regulator of EVT/invasive trophoblast cell development. In first trimester human placentas, PPARG was expressed in the EVT cell column and increased in amount as human TS cells differentiated into EVT cells. PPARG disruption impaired EVT cell differentiation. Rat invasive trophoblast cells similarly expressed PPARG. Conditional inactivation of PPARG within rat invasive trophoblast cells was used to assess the in vivo role of PPARG on the uterine-placental interface. PPARG was established as an essential cell-autonomous regulator of the invasive trophoblast cells. In conclusion, PPARG is a conserved regulator of placentation and is essential for directing trophoblast cell-guided uterine transformation.

developmental biology↗

bioRxiv2024

Effects Of Aryl Hydrocarbon Receptor Ligand TCDD On Human Trophoblast Cell Development

STUDY QUESTIONHow does activation of AHR signaling affect human trophoblast cell development and differentiation? SUMMARY ANSWERAHR activation leads to altered gene expression but does not hinder the ability of trophoblast cells to remain in a stem cell state or differentiate into essential cell types, such as extravillous trophoblast cells (EVT) or syncytiotrophoblast (ST). It also promotes the production of 2 methoxy estradiol (2ME), a compound that could influence placental development. WHAT IS KNOWN ALREADYThe placenta serves both as a nutrient delivery system and a protective barrier against environmental toxins. AHR signaling is known to mediate cellular responses to environmental pollutants, potentially affecting trophoblast cell functions, but the specific impacts of AHR activation on these cells were not fully understood. STUDY DESIGN, SIZE, DURATIONThis study utilized an in vitro model of human trophoblast stem (TS) cells to investigate the downstream effects of AHR activation. The study focused on both undifferentiated TS cells and cells undergoing differentiation. PARTICIPANTS/MATERIALS, SETTING, METHODSHuman trophoblast stem (TS) cells were used as the model system. Researchers examined the effects of TCDD exposure in both TS cells maintained in their stem state and those induced to differentiate into EVT or ST. The study assessed changes in gene expression, particularly focusing on CYP1A1 and CYP1B1, as well as the production of 2ME. MAIN RESULTS AND THE ROLE OF CHANCEAHR activation stimulated the expression of CYP1A1 and CYP1B1, key genes associated with AHR signaling, in both undifferentiated and differentiating trophoblast cells. While AHR activation did not impact the cells ability to remain in a stem state or differentiate, it increased the production of 2ME, which may influence placental function. These effects were dependent on AHR signaling. LIMITATIONS, REASONS FOR CAUTIONThis study was conducted in vitro, which may not fully replicate human conditions. Further research is needed to confirm whether these findings apply to actual placental development in humans. WIDER IMPLICATIONS OF THE FINDINGSThe results suggest that AHR signaling activated by environmental pollutants could have a subtle but significant impact on placental development through mechanisms involving AHR activation. These findings may have broader implications for understanding how environmental factors affect fetal development. STUDY FUNDING/COMPETING INTEREST(S)This work was funded by the National Institutes of Health: ES028957, HD020676, ES029280, HD105734 and the Sosland Foundation. The authors declare no conflicts of interest.

developmental biology↗

bioRxiv2024

NOTUM-MEDIATED WNT SILENCING DRIVES EXTRAVILLOUS TROPHOBLAST CELL LINEAGE DEVELOPMENT

Trophoblast stem (TS) cells have the unique capacity to differentiate into specialized cell types, including extravillous trophoblast (EVT) cells. EVT cells invade into and transform the uterus where they act to remodel the vasculature facilitating the redirection of maternal nutrients to the developing fetus. Disruptions in EVT cell development and function are at the core of pregnancy-related disease. WNT-activated signal transduction is a conserved regulator of morphogenesis of many organ systems, including the placenta. In human TS cells, activation of canonical WNT signaling is critical for maintenance of the TS cell stem state and its downregulation accompanies EVT cell differentiation. We show that aberrant WNT signaling undermines EVT cell differentiation. Notum, palmitoleoyl-protein carboxylesterase (NOTUM), a negative regulator of canonical WNT signaling, was prominently expressed in first trimester EVT cells developing in situ and upregulated in EVT cells derived from human TS cells. Furthermore, NOTUM was required for optimal human TS cell differentiation to EVT cells. Activation of NOTUM in EVT cells is driven, at least in part, by endothelial PAS domain 1 (also called hypoxia-inducible factor 2 alpha). Collectively, our findings indicate that canonical WNT signaling is essential for maintenance of human trophoblast cell stemness and regulation of human TS cell differentiation. Downregulation of canonical WNT signaling via the actions of NOTUM is required for optimal EVT cell differentiation. SIGNIFICANCEExtravillous trophoblast (EVT) cells play a critical role in transforming the uterine environment into a supportive organ facilitating embryonic/fetal development. Insufficient EVT cell-dependent uterine transformation can lead to obstetrical complications, including early pregnancy loss, preeclampsia, intrauterine growth restriction, and preterm birth. These complications carry a significant burden of morbidity and mortality for both the mother and the fetus. Notum, palmitoleoyl-protein carboxylesterase, a WNT signaling antagonist, is involved in promoting and maintaining EVT cell differentiation. This process is essential for the proper development of the placenta and is crucial for a healthy pregnancy.

developmental biology↗

bioRxiv2024

Polycomb Repressive Complex 1.1 Component, BCOR, Promotes Syncytiotrophoblast Differentiation in Mice and Humans

Early defects in placenta development are thought to underlie a range of adverse pregnancy conditions including miscarriage, fetal growth abnormalities, preeclampsia, and stillbirth. Differentiating trophoblast stem cells undergo a choreographed allocation of syncytiotrophoblast and extravillous trophoblast cells in response to signaling cues from the developing fetus and the uterine environment. The expression and activity of transcription factors and chromatin modifying enzymes change during differentiation to appropriately reshape the chromatin landscape in each cell type. We have previously found in mice that extraembryonic loss of BCOR, a conserved component of the epigenetic silencing complex Polycomb Repressive Complex 1.1 (PRC1.1), leads to a reduced labyrinth and expanded trophoblast giant cell population in the placenta. Molecular analysis of wild-type and BCOR loss-of-function male and female placentas by RNA-seq identified gene expression changes as early as E6.5. We found that BCOR is required to down regulate stem cell genes and repress factors that promote alternate lineages which leads to reduced levels of syncytiotrophoblasts. ChIP-seq experiments identified a number of directly bound functional targets including Pdgfa and Wnt7b. In humans, BCOR is mutated in X-linked syndromes involving fetal growth restriction and females with a heterozygous null mutation in BCOR can experience recurrent miscarriages. To establish a direct role for BCOR in human placental development, we used CRISPR/Cas9 to knockout BCOR in male (CT29) and female (CT30) human trophoblast stem cells. Mutant cell lines retained capacity for induced differentiation into syncytiotrophoblast and extravillous trophoblasts and exhibited minimal changes in gene expression. However, in 3D cell culture using trophoblast organoid media, BCOR knockout lines had significantly altered gene expression including homologs of stem cell genes upregulated in Bcor knockout mice. CUT&RUN experiments in self-renewing and 3D cell culture identified genes directly bound by BCOR. Single cell profiling of wild type, knockout, and a P85L pathogenic knock-in BCOR mutation showed a reduced capacity to differentiate into syncytiotrophoblasts after four days of differentiation. Together, these results suggest that BCOR is a conserved regulator of trophoblast development that represses stem cell genes during differentiation and maintains lineage fidelity by repressing genes that promote alternate cell fates.

developmental biology↗

bioRxiv2023

Human Trophoblast Stem Cells Restrict Human Cytomegalovirus Replication

Placental infection plays a central role in the pathogenesis of congenital human cytomegalovirus (HCMV) infections and is a cause of fetal growth restriction and pregnancy loss. HCMV can replicate in some trophoblast cell types, but it remains unclear how the virus evades antiviral immunity in the placenta and how infection compromises placental development and function. Human trophoblast stem cells (TSCs) can be differentiated into extravillous trophoblasts (EVTs), syncytiotrophoblasts (STBs), and organoids, and this study assessed the utility of TSCs as a model of HCMV infection in the first trimester placenta. HCMV was found to non-productively infect TSCs, EVTs, and STBs. Immunofluorescence assays and flow cytometry experiments further revealed that infected TSCs frequently only express immediate early viral gene products. Similarly, RNA-sequencing found that viral gene expression in TSCs does not follow the kinetic patterns observed during lytic infection in fibroblasts. Canonical antiviral responses were largely not observed in HCMV-infected TSCs and TSC-derived trophoblasts. Rather, infection dysregulated factors involved in cell identity, differentiation, and WNT signaling. Thus, while HCMV does not replicate in TSCs, infection may perturb trophoblast differentiation in ways that could interfere with placental function. ImportancePlacental infection plays a central role in HCMV pathogenesis during pregnancy, but the species-specificity of HCMV and the limited availability and lifespan of primary trophoblasts have been persistent barriers to understanding how infection impacts this vital organ. Human TSCs represent a new approach to modeling viral infection early in placental development. This study reveals that TSCs, like other stem cell types, restrict HCMV replication. However, infection perturbs the expression of genes involved in differentiation and cell fate determination, pointing to a mechanism by which HCMV could cause placental injury.

microbiology↗

bioRxiv2022

CITED2 Is A Conserved Regulator Of Deep Hemochorial Placentation

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 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 junctional zone, 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 development of the EVT cell lineage. We conclude that CITED2 is a conserved regulator of deep hemochorial placentation. Significance StatementThe process of establishing the uterine-placental interface is a poorly understood tissue re-engineering event that involves genetically foreign trophoblast cells breaching the immunologically secure uterus. When optimal, mother and fetus thrive, whereas failures represent the root cause of life-threatening diseases of pregnancy. CBP/p300-interacting transactivator with glutamic acid/aspartic acid-rich carboxyl terminal domain 2 (CITED2) is a transcriptional co-regulator with a conspicuous presence in trophoblast cell lineages infiltrating the uterine parenchyma. CITED2 helps coordinate the differentiation of rat and human trophoblast cells into invasive/extravillous trophoblast cells capable of transforming the uterus. These actions ensure requisite placental development and adaptations to physiological stressors. CITED2 exemplifies a conserved regulator of transcriptional events essential for establishing the uterine-placental interface.

developmental biology↗

bioRxiv2022

Regulation of human trophoblast gene expression by endogenous retroviruses

The placenta is a fast-evolving organ with large morphological and histological differences across eutherians, but the genetic changes driving placental evolution have not been fully elucidated. Transposable elements, through their capacity to quickly generate genetic variation and affect host gene regulation, may have helped to define species-specific trophoblast gene expression programmes. Here, we assessed the contribution of transposable elements to human trophoblast gene expression as enhancers or promoters. Using epigenomic data from primary human trophoblast and trophoblast stem cell lines, we identified multiple endogenous retrovirus families with regulatory potential that lie close to genes with preferential expression in trophoblast. These largely primate-specific elements are associated with inter-species gene expression differences, and are bound by transcription factors with key roles in placental development. Using genetic editing we demonstrated that several elements act as transcriptional enhancers of important placental genes, such as CSF1R and PSG5. We also identified an LTR10A element that regulates ENG expression, affecting secretion of soluble ENG, with potential implications for preeclampsia. Our data show that transposons have made important contributions to human trophoblast gene regulation, and suggest that their activity may affect pregnancy outcomes.

genetics↗

bioRxiv2019

Atypical Protein Kinase C iota (PKC{lambda}/{iota}) 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 mouse, SynTs develop via differentiation of the trophoblast progenitor cells (TSPCs) of the placenta primordium and in human, 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 (PKC{lambda}/I) plays an essential role in establishing the SynT differentiation program in trophoblast progenitors. Loss of PKC{lambda}/I in the mouse TSPCs abrogates SynT development leading to embryonic death at ~E9.0. We also show that PKC{lambda}/I-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. PKC{lambda}/I is selectively expressed in the first-trimester CTBs of a developing human placenta. Furthermore, loss of PKC{lambda}/I 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 PKC{lambda}/I signaling maintains expression of GCM1, GATA2, and PPAR{gamma}, 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 PKC{lambda}/I signaling regulates establishment of the maternal-fetal exchange surface by promoting trophoblast progenitor to SynT transition during placentation.

developmental biology↗