Primordial germ cell (PGC) development is characterized by global epigenetic remodeling, which resets genomic potential and establishes an epigenetic ground state. Here we recapitulate PGC specification in vitro from naive embryonic stem cells and characterize the early events of epigenetic reprogramming during the formation of the human and mouse germline. Following rapid de novo DNA methylation during priming to epiblast-like cells, methylation is globally erased in PGC-like cells (PGCLCs). Repressive chromatin marks (H3K9me2/3) and transposable elements are enriched at demethylation resistant regions, while active chromatin marks (H3K4me3 or H3K27ac) are more prominent at regions that demethylate faster. The dynamics of specification and epigenetic reprogramming show species-specific differences, in particular markedly slower reprogramming kinetics in the human germline. Differences in developmental kinetics between species may be explained by differential regulation of epigenetic modifiers. Our work establishes a robust and faithful experimental system of the early events of epigenetic reprogramming and its regulation in the germline. Overall design: mRNA-seq, BS-seq and PBAT of different time-points during human and mouse in vitro PGC-like cell specification
Comparative Principles of DNA Methylation Reprogramming during Human and Mouse In Vitro Primordial Germ Cell Specification.
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View SamplesDuring gastrulation, epiblast cells are pluripotent and their fate is thought to be constrained principally by their position. Cell fate is progressively restricted by localised signalling cues from areas including the primitive streak (PS). However, it is unknown whether this restriction accompanies, at the single cell level, a reduction in potency. Investigation of these early transition events in vitro is possible via the use of Epiblast Stem Cells (EpiSCs), self-renewing pluripotent cell lines equivalent to the postimplantation epiblast. Strikingly, EpiSCs express various early lineage-specific markers in self-renewing conditions. However, it is unknown whether cells that express these markers are pluripotent, spontaneously differentiated, or biased towards specific lineages. Here we show that EpiSC are inherently heterogeneous and contain two major and mutually exclusive subpopulations with PS and neural characteristics respectively. Using differentiation assays and embryo grafting we demonstrate that PS-like EpiSCs are biased towards mesoderm and endoderm differentiation but they still retain their pluripotent character. The acquisition of a PS character by undifferentiated EpiSC is mediated by paracrine Wnt signalling. Elevation of Wnt activity promotes further restriction into PS-associated cell fates which occurs via the generation of distinct clonal mesendodermal and neuromesodermal precursors. Collectively, our data suggest that primed pluripotency encompasses a range of reversible lineage-biased states reflecting the birth of pioneer lineage precursors from a pool of uncommitted EpiSCs similar to the earliest cell fate restriction events taking place in the gastrula-stage epiblast.
Distinct Wnt-driven primitive streak-like populations reflect in vivo lineage precursors.
Sex, Specimen part
View SamplesThe aim of this study is to identify genes implicated in the early steps of the autoimmune process, prior to inflammation in type 1 diabetes. Early Insulin AutoAntibodies (E-IAA) have been used as subphenotypic marker to select individual animals as type 1 diabetes prone and to compare gene expression patterns with insulin autoantibody negative NOD.
Early over expression of messenger RNA for multiple genes, including insulin, in the Pancreatic Lymph Nodes of NOD mice is associated with Islet Autoimmunity.
Age
View SamplesIn mammals, resident dermal macrophages (Ms) are subverted by Leishmania (L.) amazonensis amastigotes as host cells permissive for parasite multiplication. These Leishmania are living within a communal parasitophorous vacuole (PV) and are expected to trigger unique M transcriptional signatures. We performed a transcription profiling of mouse Ms harboring amastigotes to get insights into their reprogramming as host cells for parasite multiplication. BALB/c mouse bone marrow-derived Ms were either loaded or not with four amastigotes on average. Twenty four hours later, when amastigotes multiply, total RNA from M cultures was prepared, amplified and hybridized onto Affymetrix Mouse430_2 GeneChips. The outcome recorded a total of 1,248 probe-sets showing significant differential expression. Comparable fold-change values for a handful of genes were obtained between Affymetrix technology and the more sensitive RTqPCR method. Ingenuity Pathway Analysis software pinpointed the up-regulation of the sterol biosynthesis pathway (P-value = 1.31e-02) involving several genes (1.95 to 4.30 fold-change values), and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signaling. Our findings suggest that amastigotes exploit the M lipid and polyamine pathways to multiply efficiently, and induce a counter-inflammatory environment to expand their dermis niche.
Transcriptional signatures of BALB/c mouse macrophages housing multiplying Leishmania amazonensis amastigotes.
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View SamplesTo determine the modulation of gene expression of mouse BMDCs in the presence of living intracellular Leishmania amazonensis amastigotes
Sorting of Leishmania-bearing dendritic cells reveals subtle parasite-induced modulation of host-cell gene expression.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
NF-κB activation impairs somatic cell reprogramming in ageing.
Specimen part, Disease, Disease stage, Treatment
View SamplesTranscriptional profiling of human control and Nstor-Guillermo Progeria Syndrome (NGPS) mesenchymal stem cells (MSCs).
NF-κB activation impairs somatic cell reprogramming in ageing.
Specimen part, Disease, Disease stage, Treatment
View SamplesXbp1 is a major transcription factor in the unfolded protein response. To uncover its function in DCs we generated a conditional KO for Xbp1 in dendritic cells. We here compare the expression of mRNAs in two different splenic DC subpopulations, CD8a and CD11b DCs in both WT and KO mice.
The unfolded-protein-response sensor IRE-1α regulates the function of CD8α+ dendritic cells.
Specimen part
View SamplesDefining the aging-cancer relationship is a challenging task. Mice deficient in Zmpste24, a metalloproteinase mutated in human progeria and involved in nuclear prelamin A maturation, recapitulate many features of aging. However, their short lifespan and cell-intrinsic and -extrinsic alterations restrict the application and interpretation of carcinogenesis protocols. To circumvent these limitations we have generated Zmpste24 mosaic mice. Interestingly, these mice develop normally - revealing cell-extrinsic mechanisms are preeminent in progeria- and display decreased incidence of infiltrating oral carcinomas. Moreover, ZMPSTE24 knock-down reduces human cancer cell invasiveness. Our results disclose the ZMPSTE24-prelamin A system as an example of antagonistic pleiotropy on cancer and aging, support the potential of cell-based and systemic therapies for progeria, and highlight ZMPSTE24 as a new anticancer target.
Prelamin A causes progeria through cell-extrinsic mechanisms and prevents cancer invasion.
Cell line
View SamplesAbstract: Drought is the primary cause of global agricultural losses and represents a major threat to worldwide food security. Currently, plant biotechnology stands out as the most promising strategy to increase crop growth in rain-fed conditions. The main mechanisms underlying drought resistance have been uncovered by studies of plant physiology and by engineering crops with drought-resistant genes. However, plants with enhanced drought resistance usually display lower levels of growth, highlighting the need to search for novel strategies capable of uncoupling drought resistance from growth. Here, we show that the brassinosteroid family of receptors, in addition to promoting growth, guides phenotypic adaptation to a great variety of drought stress traits analyzed herein. Whilst mutations in the ubiquitously localized BRI1 receptor pathway show an enhanced drought resistance at the expense of plant growth, we found that vascular-enriched BRL3 receptors confer drought tolerance without penalizing overall growth. Systematic analyses reveal that upon drought stress the BRL3 receptor pathway triggers the synthesis and mobilization of osmoprotectant metabolites, mainly proline and sugars. This preferentially occurs in the vascular tissues of the roots and favors overall plant growth. Altogether, our results uncover a new role for the spatial control of BR signaling in drought tolerance, and offer a novel strategy to address food security issues in an increasingly water-limited climate. Overall design: 28 days old root system were collected from soil, quickly washed in water and flash-frozen. Experiment with a bifactorial design. Factor one is the genotype, which include WT (Col-0) and 35S:BRL3. Factor two is the condition, which include control (Properly watered) and 5 days of drought (water-hold) conditions. 3 Biological replicates were collected per each genotype and condition.
Overexpression of the vascular brassinosteroid receptor BRL3 confers drought resistance without penalizing plant growth.
Specimen part, Subject
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