Project description:Complete Hydatidiform Mole (HM) is a gestational trophoblastic disease resulting in hyper proliferation of trophoblast cells and absence of embryo development. Mutations in NLRP7 gene is a major cause of familial recurrent complete HM, where no embryonic tissue is present during the pregnancy. NLRP7 is a novel protein and its function is poorly understood. Lack of NLRP7 in the mouse genome and challenges in studying human embryogenesis as well as human trophoblast differentiation has prevented elucidation of the pathophysiology of this disease and the function of NLRP7 in HM. Here, we established an in vitro model of HM using NLRP7 deficient patient-derived human induced pluripotent stem cells (iPSCs). Whole transcriptome profiling during trophoblast differentiation revealed that NLRP7 deficiency results in precocious downregulation of pluripotency factors, activation of trophoblast genes and promotes maturation of differentiated extraembryonic cell types such as syncytiotrophoblasts. We further showed that these phenotypes are dependent on BMP4 signaling and BMP pathway inhibition prevented excessive trophoblast differentiation of HM-iPSCs. Taken together, this novel human iPSC model of a genetic placental disease recapitulates aspect of trophoblast biology and sheds light on early human embryogenesis by identifying NLRP7 as an important regulator of this process.
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Our integrated analysis reveals differences in the relative abundance and activities of distinct chromatin modules. We identify a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin, and H3K27me3 enrichment at promoters of lineage-determining genes, including trophoblast regulators. PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, while inhibition of PRC2 promotes trophoblast fate induction and cavity formation in human blastoids. Together, our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates.
Project description:YY1 is a sequence-specific DNA-binding transcription factor that has many important biological roles. However, its function in trophoblasts at the maternal-foetal interface remains to be elucidated. In this study, we used an mRNA microarray and quantitative reverse transcription-PCR and compared the YY1 mRNA expression level in trophoblasts between patients with recurrent miscarriage (RM) and healthy control subjects. Our results revealed that YY1 mRNA expression was significantly lower in the trophoblasts of the RM group compared with the healthy control group. Furthermore, immunofluorescence and immunohistochemical data showed that YY1 was highly expressed in human placental villi during early pregnancy, especially in cytotrophoblast cells and invasive extravillous trophoblasts, and it was expressed at a much lower level in the placental villi of term pregnancy. YY1 overexpression enhanced the invasion and proliferation of trophoblasts, while knockdown of YY1 repressed these effects. Antibody array screening revealed that YY1 significantly promoted MMP2 expression in trophoblasts. Bioinformatics analysis identified three YY1-binding sites in the MMP2 promoter region, and chromatin immunoprecipitation analysis verified that YY1 binds directly to its promoter region. Importantly, inhibition of YY1 by siRNA clearly decreased trophoblast invasion in an ex vivo explant culture model. Overall, our findings revealed a new regulatory pathway of YY1/MMP2 in trophoblast cells invasion during early pregnancy, and indicated that YY1 may be involved in the pathogenesis of RM. Total RNA was isolated using Trizol from trophoblast cells from three healthy controls (HC) and three recurrent miscarriage (RM) patients. Total RNA were extracted and used for hybridizing Affymetrix chips (GeneChip® Human Transcriptome Array 2.0(HTA2.0)). Data were normalised by gcRMA method and raw p-values adjusted by Bonferroni procedure (1%).
Project description:Genome wide DNA methylation profiling of hESC in the untransduced, scrambled control and with knockdown of NLRP7 in undifferentiated and BMP4 differentiated states using the Illumina HumanMethylation 450 BeadChip. Several genomic sites exhibit altered methylation upon knocking down NLRP7. Bisulphite converted DNA from 3 replicates of untransduced, scrambled control and NLRP7 knockdown in the undifferentiated and BMP differentiated groups were hybridised to the Illumina Human Methylation 450 Beadchip.
Project description:Critical roles for DNA methylation in embryonic development are well established, but less is known about the roles of DNA methylation during trophoblast development, the extraembryonic lineage that gives rise to the placenta. Here we dissected the role of DNA methylation in trophoblast development by performing mRNA and DNA methylation profiling of Dnmt3a/3b-null trophoblast. We find that most gene deregulation is explained by an erasure of maternal methylation in the oocyte, but partially independent of loss of imprinting of the trophoblast-essential Ascl2 gene. Our results reveal that maternal DNA methylation controls multiple differentiation and physiological processes in trophoblast via both imprinting-dependent and -independent mechanisms. mRNA-seq and WGBS-seq of maternal Dnmt3a/3b-null trophoblast; mRNA-seq of maternal Ascl2 KO trophoblast
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we apply multi-omics to comprehensively define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Integrating the chromatin-bound proteome and histone modification data sets reveals differences in the relative abundance and activities of distinct chromatin modules, identifying a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin. Single-cell approaches and human blastoid models reveal that PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, and inhibiting PRC2 promotes trophoblast fate induction and cavity formation. Our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates.
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we apply multi-omics to comprehensively define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Integrating the chromatin-bound proteome and histone modification data sets reveals differences in the relative abundance and activities of distinct chromatin modules, identifying a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin. Single-cell approaches and human blastoid models reveal that PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, and inhibiting PRC2 promotes trophoblast fate induction and cavity formation. Our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates. Data originating from the LC-MS/MS analysis of the histone PTMs can be consulted via this project.
Project description:Genome wide DNA methylation profiling of hESC in the untransduced, scrambled control and with knockdown of NLRP7 in undifferentiated and BMP4 differentiated states using the Illumina HumanMethylation 450 BeadChip. Several genomic sites exhibit altered methylation upon knocking down NLRP7.
Project description:Embryonic (ES) and epiblast (EpiSC) stem cells are pluripotent but committed to an embryonic lineage fate. Conversely, trophoblast (TS) a nd extraembryonic endoderm (XEN) stem cells contribute predominantly to tissues of the placenta and yolk sac, respectively. Here we show that each of these four stem cell types is defined by a unique DNA methylation profile. Despite their distinct developmental origin, TS and XEN cells share key epigenomic hallmarks, chiefly characterized by robust DNA methylation of embryo-specific developmental regulators, as well as a subordinate role of 5-hydroxymethylation. We also observe a substantial methylation reinforcement of pre-existing epigenetic repressive marks that specifically occurs in extraembryonic stem cells compared to in vivo tissue, presumably due to continued high Dnmt3b expression levels. These differences establish a major epigenetic barrier between the embryonic and extraembryonic stem cell types. In addition, epigenetic lineage boundaries also separate the two extraembryonic stem cell types by mutual repression of key lineage-specific transcription factors. Thus, global DNA methylation patterns are a defining feature of each stem cell type that underpin lineage commitment and differentiative potency of early embryo-derived stem cells. Our detailed methylation profiles identify a cohort of developmentally regulated sequence elements, such as orphan CpG islands, that will be most valuable to uncover novel transcriptional regulators and pivotal M-^QM-^QgatekeeperM-^RM-^R genes in pluripotency and lineage differentiation.
Project description:YY1 is a sequence-specific DNA-binding transcription factor that has many important biological roles. However, its function in trophoblasts at the maternal-foetal interface remains to be elucidated. In this study, we used an mRNA microarray and quantitative reverse transcription-PCR and compared the YY1 mRNA expression level in trophoblasts between patients with recurrent miscarriage (RM) and healthy control subjects. Our results revealed that YY1 mRNA expression was significantly lower in the trophoblasts of the RM group compared with the healthy control group. Furthermore, immunofluorescence and immunohistochemical data showed that YY1 was highly expressed in human placental villi during early pregnancy, especially in cytotrophoblast cells and invasive extravillous trophoblasts, and it was expressed at a much lower level in the placental villi of term pregnancy. YY1 overexpression enhanced the invasion and proliferation of trophoblasts, while knockdown of YY1 repressed these effects. Antibody array screening revealed that YY1 significantly promoted MMP2 expression in trophoblasts. Bioinformatics analysis identified three YY1-binding sites in the MMP2 promoter region, and chromatin immunoprecipitation analysis verified that YY1 binds directly to its promoter region. Importantly, inhibition of YY1 by siRNA clearly decreased trophoblast invasion in an ex vivo explant culture model. Overall, our findings revealed a new regulatory pathway of YY1/MMP2 in trophoblast cells invasion during early pregnancy, and indicated that YY1 may be involved in the pathogenesis of RM.