Maternal undernutrition induces cell signalling and metabolic dysfunction in undifferentiated mouse embryonic stem cells
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ABSTRACT: The peri-conceptional environment can induce permanent changes in embryo phenotype which alter development and associate with later disease susceptibility. Thus, mouse maternal low protein diet (LPD) fed exclusively during preimplantation is sufficient to cause cardiovascular, metabolic and neurological dysfunction in adult offspring. Embryonic stem cell (ESC) lines were generated from LPD and control NPD C57BL/6 blastocysts and characterised by transcriptomics, metabolomics, bioinformatics and molecular/cellular studies to assess early potential mechanisms in dietary environmental programming. Previously, we showed these lines retain cellular and epigenetic characteristics of LPD and NPD embryos after several passages. Here, three main changes were identified in LPD ESC lines. First, their derivation capacity was reduced but pluripotency marker expression was similar to controls. Second, LPD lines had impaired Mitogen-activated protein kinase (MAPK) pathway with altered gene expression of several regulators (e.g., Maff, Rassf1, JunD), reduced ERK1/2 signalling capacity and poorer cell survival characteristics which may contribute to reduced derivation. Third, LPD lines had impaired glucose metabolism comprising reduced upstream enzyme expression (e.g., Gpi, Mpi) and accumulation of metabolites (e.g., glucose-6-P, fructose-6-P) above the phosphofructokinase (PFK) gateway with PFK enzyme activity reduced. ESC lines may therefore permit investigation of peri-conceptional programming mechanisms with reduced need for animal experimentation.
Project description:We present genome-scale maps of DNA methylation in early human development and perform comparative analysis to mouse that confirm a conserved global erasure of the paternal genome. We find that while many global features of the early embryo are consistent between the two species, the target sequences in which DNA methylation is maintained are distinct. Repetitive elements show a broader range of class specific behaviors in the human embryo and a larger degree of methylation escape in human sperm. We identify thousands of differentially methylated regions (DMRs) that are likely of maternal origin and found that these gamete contributed DMRs are far more species-specific than expected given the conservation of canonical imprint control regions (ICRs). Finally, we extended our studies to the derivation of new human embryonic stem cell (ESC) lines and found notable divergences in DNA methylation signatures from those found in the human embryo and different mouse ESC derivation conditions. Comparison of DNA methylation patterns in human early development, human ESC derivation and mouse ESC derivation
Project description:Translating genetic findings for neurodevelopmental and psychiatric disorders (NPD) into actionable disease biology would benefit from large-scale and unbiased functional studies of NPD genes. Leveraging the cytosine base editing (CBE) system, here we developed a pipeline for clonal loss-of-function (LoF) allele mutagenesis in human induced pluripotent stem cells (hiPSCs) by introducing premature stop-codons (iSTOP) that lead to mRNA nonsense-mediated-decay (NMD) or protein truncation. We tested the pipeline for 23 NPD genes on 3 hiPSC lines and achieved highly reproducible, efficient iSTOP editing in 22 NPD genes. Using RNAseq, we confirmed their pluripotency, absence of chromosomal abnormalities, and NMD. Interestingly, for three schizophrenia risk genes (SETD1A, TRIO, CUL1), despite the high efficiency of base editing, we only obtained heterozygous LoF alleles, suggesting their essential roles for cell growth. We replicated the reported neural phenotypes of SHANK3-haploinsufficiency and found CUL1-LoF reduced neurite branches and synaptic puncta density. This iSTOP pipeline enables a scaled and efficient LoF mutagenesis of NPD genes, yielding an invaluable shareable resource.
Project description:Derivation of embryonic stem cells (ESC) genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing any immunorejection issues. However, no primate nuclear transfer embryonic stem (ntES) cell lines have been derived to date. Here, we used a modified SCNT technique to produce rhesus macaque SCNT blastocysts at a relatively high efficiency from adult donor cells and we successfully derived two primate ntES cell lines from 304 oocytes (an overall efficiency of 0.7%). Nuclear and mitochondrial DNA analysis confirmed the ntES cell lines were derived from rhesus monkey SCNT blastocysts and both rhesus monkey ntES cell lines exhibited a normal ESC morphology, expressed key stemness markers, were transcriptionally indistinguishable from control ESC lines and differentiated into multiple cell types. This is, to our knowledge, the first confirmed derivation of primate ntES cell lines. Keywords: rhesus monkey somatic cell nuclear transfer embryonic stem cells
Project description:Female human ESC-lines can carry active X-chromosomes (Xa) or an XIST-RNA- coated inactive X-chromosome (Xi XIST+ ). Additionally, many ESC-lines have abnormal X-chromosome-inactivation (XCI)-states where the Xi no longer expresses XIST-RNA and has transcriptionally active regions (eroded Xi=Xe). The fate of each XCI-state upon differentiation is unclear because individual lines often contain a mixture of XCI-states. Here, we established homogeneous XiXa, XeXa, and XaXa ESC-lines. We found that these lines were unable to initiate XIST-expression and X-chromosome- wide silencing upon differentiation indicating that the ESC XCI-state is maintained in differentiated cells. Consequently, differentiated XeXa and XaXa cells displayed higher levels of X-linked gene-expression than XiXa cells. Although global transcriptional compensation between X-chromosomes and autosomes is not required for female ESC-differentiation, the degree of X-chromosome- silencing influences differentiation efficiencies. Our data suggest that the Xi XIST+ Xa state is inherent to human ESCs and that all other XCI-states, including XaXa, are abnormal and arise during ESC-derivation or maintenance.
2016-12-15 | GSE91072 | GEO
Project description:Nodule RNAseq from M. truncatula NPD knockout lines
Project description:Female human ESC-lines can carry active X-chromosomes (Xa) or an XIST-RNA-coated inactive X-chromosome (XiXIST+). Additionally, many ESC lines have abnormal X-chromosomeinactivation (XCI)-states where the Xi no longer expresses XIST-RNA and has transcriptionally active regions (eroded Xi=Xe). The fate of each XCI-state upon differentiation is unclear because individual lines often contain a mixture of XCI-states. Here, we established homogeneous XiXa, XeXa, and XaXa ESC-lines. Employing RNA-FISH, RNA-sequencing and DNA methylation analyses, we found that these lines were unable to initiate XIST-expression and X-chromosome-wide silencing upon differentiation indicating that the ESC XCI-state is maintained in differentiated cells. Consequently, differentiated XeXa and XaXa cells displayed higher levels of X-linked gene-expression than XiXa cells. Although global transcriptional compensation between X-chromosomes and autosomes is not required for female ESC-differentiation, the degree of X-chromosome-silencing influences differentiation efficiencies. Our data suggest that the XiXIST+Xa state is inherent to human ESCs and that all other XCI-states, including XaXa, are abnormal and arise during ESC-derivation or maintenance.
Project description:Female human ESC-lines can carry active X-chromosomes (Xa) or an XIST-RNA-coated inactive X-chromosome (XiXIST+). Additionally, many ESC lines have abnormal X-chromosomeinactivation (XCI)-states where the Xi no longer expresses XIST-RNA and has transcriptionally active regions (eroded Xi=Xe). The fate of each XCI-state upon differentiation is unclear because individual lines often contain a mixture of XCI-states. Here, we established homogeneous XiXa, XeXa, and XaXa ESC-lines. Employing RNA-FISH, RNA-sequencing and DNA methylation analyses, we found that these lines were unable to initiate XIST-expression and X-chromosome-wide silencing upon differentiation indicating that the ESC XCI-state is maintained in differentiated cells. Consequently, differentiated XeXa and XaXa cells displayed higher levels of X-linked gene-expression than XiXa cells. Although global transcriptional compensation between X-chromosomes and autosomes is not required for female ESC-differentiation, the degree of X-chromosome-silencing influences differentiation efficiencies. Our data suggest that the XiXIST+Xa state is inherent to human ESCs and that all other XCI-states, including XaXa, are abnormal and arise during ESC-derivation or maintenance.
Project description:We derive experimental conditions for the derivation of marmoset trophoblast like cells. Marmoset naïve PSC form extraembryonic mesoderm in human TSC conditions, whilst TGFβ/NODAL, FGF/ERK and WNT signalling control marmoset peri- and postimplantation trophoblast identity.
Project description:In this study, we established bovine embryonic stem cell (bESC) lines from early (eBL) and full (BL) blastocysts to determine the efficiency of bESC derivation from an earlier embryonic stage and compare the characteristics of the resulting lines. Using established medium and protocols for derivation of primed bESCs from expanded blastocysts, we derived bESC lines from eBLs and BLs with the same efficiency (4/12 each, 33%). Regardless of original blastocyst stage, bESC lines had a similar phenotype, including differentiation capacity, stable karyotype, and pluripotency marker expression over feeder-free transition and long-term culture. Transcriptome and functional analyses indicated that eBL- and BL-derived lines were in primed pluripotency. We additionally compared RNA-sequencing data from our lines to bovine embryos and stem cells from other recent reports, finding that base medium was the predominant source of variation among cell lines. In conclusion, our results show that indistinguishable bESC lines can be readily derived from eBL and BL, widening the pool of embryos available for bESC establishment. Finally, our investigation points to sources of variation in cell phenotype among recently reported bESC conditions, opening the door to future studies investigating the impact of factors aside from signaling molecules on ESC derivation, maintenance, and performance.
Project description:Genome-wide association studies (GWAS) have identified many risk genes for neuropsychiatric disorders (NPD) such as schizophrenia (SCZ). However, functional interpretation of these GWAS findings remains challenging; a major hurdle is that polygenic risk may manifest its effect conditionally upon neural activation, i.e., context-dependent. Human induced pluripotent stem cell (hiPSC)-derived neurons are a tractable cellular model for ascertaining context-dependent polygenic effects, e.g., neural activation that may mimic the physiological effects of environmental stimuli. Here, we modelled neural activation by depolarisation using high potassium chloride (KCl) in co-cultured excitatory/inhibitory neurons of 100 hiPSC lines (28 from SCZ donors), followed by assaying single-cell multiomes (scRNA/ATAC-seq) of over 700,000 nuclei from neurons at 0 hr (unstimulated), 1 hr (early response), and 6 hr (later response) of high KCI exposure. We linked genes with open chromatin peaks for each main neural subtype (GABAergic inhibitory, NEFM+ or NEFM-excitatory neurons) and confirmed a significant correlation between peak accessibility and target gene expression. Compared to static genes/peaks, dynamic ones, specifically those activity-upregulated, were more enriched for NPD GWAS risk, with the most robust enrichment for SCZ. Based on the dynamic gene expression pattern across the three time points, we found NPD risk genes tend to be continuously upregulated (i.e., with up-up dynamics). We further analysed context-specific SCZ-associated differentially expressed genes (DEGs) using MAST for single neurons of 28 SCZ cases and 72 controls. We found that 3-5%, 4-6%, and 15-23% of genes were SCZ-associated DEGs in NEFM+ excitatory, NEFM- excitatory, and GABAergic neurons, respectively, most of which were cell activity-specific. Notably, we found that SCZ-associated DEGs in high-activity neurons were more enriched for synapse-related GO terms and NPD risk genes. Interestingly, upstream regulatory sequences of the stimulation-specific SCZ-associated DEGs were enriched for binding sites of TCF4, which is a strong GWAS risk gene and was considered the master regulator of other SCZ-related genes. Moreover, the upregulated genes in SCZ cases in the stimulated (only at 6hr) NEFM+ excitatory neurons showed strong enrichment for GO terms related to cholesterol synthesis. Single-neuron DEG analysis for 28 SCZ cases and 28 matched controls gave similar results. Our study suggests that many NPD genes may only elicit disease-relevant effects upon neuronal activation, providing novel insights into how polygenic risk factors interact with environmental stimuli for NPD.