Placental trophoblasts are key determinants of in utero development. Mouse trophoblast stem cells (mTSCs), which were first derived over a decade ago, are a powerful cell culture model for studying their self-renewal or differentiation. Our attempts to isolate an equivalent population from the trophectoderm of human blastocysts generated colonies that quickly differentiated in vitro. This finding suggested that the human placenta has another progenitor niche. Here we show that the chorion is one such site. Initially, we immunolocalized pluripotency factors and trophoblast fate determinants in the early-gestation placenta, amnion and chorion. Immunoreactive cells were numerous in the chorion. We isolated these cells and plated them in medium containing FGF and an inhibitor of activin/nodal signaling, which is required for human embryonic SC self-renewal. Colonies of polarized cells with a limited lifespan emerged. Trypsin dissociation yielded continuously self-replicating monolayers. Colonies and monolayers formed the two major human trophoblast lineagesmultinucleate syncytiotrophoblasts and invasive cytotrophoblasts (CTBs). Transcriptional profiling experiments revealed the factors associated with the self-renewal or differentiation of human chorionic trophoblast progenitor cells (TBPCs). They included imprinted genes, NR2F1/2, HMGA2 and adhesion molecules that were required for TBPC differentiation. Together, the results of these experiments suggested that the chorion is one source of epithelial CTB progenitors. These findings explain why CTBs of fully formed chorionic villi have a modest mitotic index and identify the chorionic mesoderm as a niche for TBPCs that support placental growth.
Establishment of human trophoblast progenitor cell lines from the chorion.
No sample metadata fields
View SamplesDuplication of the genome in mammalian cells occurs in a defined temporal order referred as its replication-timing program (RT). RT is regulated in units of 400-800 Kb referred as replication domains (RDs) and changes dynamically during development. Changes in RT are generally coordinated with transcriptional competence and changes in sub-nuclear position. We generated genome-wide RT profiles for 29 distinct human cell types including embryonic stem cell (hESC)-derived, primary cells and established cell lines representing intermediate stages of endoderm, mesoderm, ectoderm and neural crest (NC) development. We identified clusters of RDs that replicate at unique times in each stage (RT signatures). Surprisingly, transcriptome data revealed that, despite an overall correlation between early replication and transcriptional activity, most genes that switched RT during differentiation can be expressed when late replicating. Intriguingly, this class of genes was nonetheless induced to high expression levels prior to a late to early RT switch and down-regulated after the switch back to late replication. These results clarify the complex relationship between transcription and RT and identify classes of genes that behave as potential drivers of the RT switch vs. those that may depend upon an RT switch for transcriptional induction.
Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification.
No sample metadata fields
View SamplesAkt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays a critical role in the regulation of several cellular processes including cell proliferation and apoptosis. In this study, we utilized Akt1+/+ and Akt1-/- C57/Bl6 female mice to demonstrate that Akt1 is required for normal mammary gland postnatal development and homeostasis. Akt1 deficiency resulted in severely delayed postnatal mammary gland growth as well as a significant decrease in the number of terminal end buds during puberty. Adult Akt1-/- mammary glands exhibited significantly fewer alveolar buds coupled with a significant increase in epithelial cell apoptosis compared to their wild-type counterparts. Microarray analysis revealed that Akt1 deficiency resulted in several altered gene expression changes and biological processes in adult mammary glands, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands by both microarray and RT-PCR validation.
Akt1 is essential for postnatal mammary gland development, function, and the expression of Btn1a1.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesGestational diabetes mellitus (GDM) affects approximately 18% of pregnancies in the United States and increases the risk of adverse health outcomes in the offspring. These adult disease propensities may be set by anatomical and molecular alterations in the placenta associated with GDM. To assess the mechanistic aspects of fetal programming, we measured genome-wide methylation (Infinium HumanMethylation450 Beadchips) and expression (Affymetrix Transcriptome Microarrays) in placental tissue of 41 GDM cases and 41 matched pregnancies without maternal complications from the Harvard Epigenetic Birth Cohort. Specific transcriptional and epigenetic perturbations associated with GDM status included alterations in the major histocompatibility complex (MHC) region, which were validated in an independent cohort, the Rhode Island Child Health Study. Gene ontology enrichment among gene regulation influenced by GDM revealed an over-representation of immune response pathways among differential expression, reflecting these coordinated changes in the MHC region. Our study represents the largest investigation of transcriptomic and methylomic differences associated with GDM, providing comprehensive insight into the molecular basis of GDM induced fetal (re)programming.
Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesObesity is linked to the development of metabolic disorders. Expansion of white adipose tissue (WAT) from hypertrophy of pre-existing adipocytes and/or differentiation of precursors into new mature adipocytes contributes to obesity. We found that Nck2 expression is largely restricted to WAT, raising the hypothesis that it may play a unique function in that tissue. Using mice lacking Nck2, we found that Nck2 regulates adipocyte hypertrophy thus contributing to increased adiposity and progressive glucose intolerance, insulin resistance and hepatic steatosis. These findings were recapitulated in humans such that Nck2 expression in omental WAT was inversely correlated with the degree of obesity. Mechanistically, Nck2 deficiency promoted the induction of an adipocyte differentiation program and signaling by the PERK-eIF2a-ATF4 pathway in agreement with a role for the unfolded protein response in adipogenesis. These findings uncover Nck2 as a novel regulator of adipogenesis and that perturbation in its functionality contributes to adiposity-related metabolic disorders. Overall design: Differential gene expression profile between epididymal white adipose tissue of Nck2-/- and Nck2+/+ mice by RNA sequencing (Illumina HiSEq 2000)
Nck2 Deficiency in Mice Results in Increased Adiposity Associated With Adipocyte Hypertrophy and Enhanced Adipogenesis.
No sample metadata fields
View SamplesEpigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents.
Selective inhibition of p300 HAT blocks cell cycle progression, induces cellular senescence, and inhibits the DNA damage response in melanoma cells.
Cell line, Treatment, Time
View SamplesThe white adipose tissue (WAT) rapidly loses mass when mice are fed a diet containing trans-10, cis-12 conjugated linoleic acid (t10c12 CLA). A microarray analysis of WAT due to CLA feeding was performed to better define the processes and genes involved. WAT weight decreased by ca. 80% over 17 days of feeding a 0.5% t10c12 CLA diet. The lipid volume decreased by 90% and the number of adipocytes and total cells were reduced by15% and 47%, respectively. Microarray profiling of replicated pools of control and treated mice (n=140) at seven time points over the 17day feeding indicated between 2798 to 4318 genes showed mRNA changes of 2-fold or more. Transcript levels for genes of glucose and fatty acid import or biosynthesis were significantly reduced. A prolific inflammation response was indicated by the 2 to100-fold induction of many cytokine transcripts, including those for IL-6, IL1?, TNF ligands, and CXC family members
Trans-10, cis-12 conjugated linoleic acid causes inflammation and delipidation of white adipose tissue in mice: a microarray and histological analysis.
Age
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse 3T3-L1 adipocyte tissue culture. The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT). The early transcriptome changes in WAT were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Sex, Specimen part
View Samples