IMR-32 cells were subjected to lentiviral YRNA infection or nELAVL RNAi and/or UV stress followed by RNAseq analysis to monitor RNA level changes Overall design: RNA from IMR-32 cells was Trizol extracted, Ribominus selected and submitted for high-throughput sequencing.
Regulatory consequences of neuronal ELAV-like protein binding to coding and non-coding RNAs in human brain.
No sample metadata fields
View SamplesThe hair follicle (HF) is a complex miniorgan that serves as an ideal model system to study stem cell (SC) interactions with the niche during growth and regeneration. Dermal papilla (DP) cells are required for activating SCs during the adult hair cycle, but the signal exchange between niche and SC precursors/transit amplifying progenitor cells (TACs) that regulates HF morphogenetic growth is largely unknown. Here we use six transgenic reporters to isolate 14 major skin and HF cell populations. With next-generation RNA sequencing we characterize their transcriptomes and define unique molecular signatures. SC precursors, TACs and the DP niche express a plethora of known and novel ligands and receptors. Signaling interaction network analysis reveals a birds-eye view of pathways implicated in epithelial-mesenchymal interactions. Using a systematic tissue-wide approach this work provides a comprehensive platform, linked to an interactive online database, to identify and further explore the SC/TAC/niche crosstalk regulating HF growth. Overall design: FACS was used to isolate specific cell types from P5 mouse back skin
Signaling Networks among Stem Cell Precursors, Transit-Amplifying Progenitors, and their Niche in Developing Hair Follicles.
Specimen part, Subject
View SamplesWe co-isolated hair follicle placode and dermal condensate cells along with other specific cell types from E14.5 embryonic mouse skin. With next-generation RNA-sequencing we defined gene expression patterns in the context of the entire embryonic skin. Overall design: FACS was used to isolate specific cell types from E14.5 embryonic mouse skin.
An Integrated Transcriptome Atlas of Embryonic Hair Follicle Progenitors, Their Niche, and the Developing Skin.
No sample metadata fields
View SamplesIn this study, we have uncovered novel proteolytic processing of the histone H3 tail in senescence models in primary fibroblasts and melanocytes. Cleavage of H3 tail occurs at two distinct residues and is mediated by Cathepsin L. We show that variant H3.3 is preferentially cleaved, and that cleaved histones are associated with chromatin and incorporated into nucleosomes. We also found that the histone chaperone ASF1a is required for chromatin incorporation of the cleaved histone species. Further, we show that overexpression of cleaved H3.3 induces a senescence program in fibroblasts in the absensence of oncogenic signaling. Overall design: For the RNA-seq studies, growing IMR90 fibroblasts were compared to cells induced to senesce via oncogene activation or cleaved H3.3 overexpression. Growing controls consist of IMR90 cells infected with empty retroviral construct pBabe and grown under normal conditions for 13 days prior to RNA isolation. For oncogene-induced senescence samples, IMR90s carrying a tamoxifen-inducible H-RasV12 retroviral construct were induced to senesce by addition of 10nM tamoxifen to the media for 8 days. Finally, IMR90s were infected with a retroviral construct expressing the cleaved form of H3.3 with a C-terminal Flag tag. RNA samples form this group were isolated at days 3 (early) and 13 (late) post-infection. In all cases, total RNA samples were isolated using RNeasy kit (Qiagen) and prepared at the Icahn School of Medicine at Mount Sinai Genomics Core Facility for poly A library construction and sequencing on IlluminaHiSeq 2500.
Histone H3.3 and its proteolytically processed form drive a cellular senescence programme.
No sample metadata fields
View SamplesA number of key regulators of mouse embryonic stem (ES) cell identity, including the transcription factor Nanog, show strong expression fluctuations at the single cell level. The molecular basis for these fluctuations is unknown. Here we used a genetic complementation strategy to investigate expression changes during transient periods of Nanog downregulation. Employing an integrated approach, that includes high-throughput single cell transcriptional profiling and mathematical modelling, we found that early molecular changes subsequent to Nanog loss are stochastic and reversible. However, analysis also revealed that Nanog loss severely compromises the self-sustaining feedback structure of the ES cell regulatory network. Consequently, these nascent changes soon become consolidated to committed fate decisions in the prolonged absence of Nanog. Consistent with this, we found that exogenous regulation of Nanog-dependent feedback control mechanisms produced more a homogeneous ES cell population. Taken together our results indicate that Nanog-dependent feedback loops play a role in controlling both ES cell fate decisions and population variability.
Nanog-dependent feedback loops regulate murine embryonic stem cell heterogeneity.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Polycomb repressive complex 2 (PRC2) silences genes responsible for neurodegeneration.
Age, Specimen part
View SamplesWe used an integrated computational/experimental systems biology approach to identify upstream protein kinases that regulate gene expression changes in kidneys of HIV-1 transgenic mice (Tg26), which have significant tubulo-interstitial fibrosis (TIF) and glomerulosclerosis (GS). We identified the homeo-domain interacting protein kinase 2 (HIPK2) as a key regulator of TIF and GS. HIPK2 was upregulated in kidneys of Tg26 and patients with various kidney diseases. HIV infection increased the protein level of HIPK2 by promoting oxidative stress, which inhibited Siah1-mediated proteasomal degradation of HIPK2.
A systems approach identifies HIPK2 as a key regulator of kidney fibrosis.
Sex, Specimen part, Cell line
View SamplesNormal brain function critically depends on the interaction between highly specialized neurons that operate within anatomically and functionally distinct brain regions. The fidelity of neuronal specification is contingent upon the robustness of the transcriptional program that supports the neuron type-specific patterns of gene expression. Changes in neuron type-specific gene expression are commonly associated with neurodegenerative disorders including Huntingtons and Alzheimers disease. The neuronal specification is driven by gene expression programs that are established during early stages of neuronal development and remain in place in the adult brain. Here we show that the Polycomb repressive complex 2 (PRC2), which supports neuron specification during early differentiation, contributes to the suppression of the transcription program that can be detrimental for the adult neuron function. We show that PRC2 deficiency in adult striatal neurons and in cerebellar Purkinje cells impairs the maintenance of neuron-type specific gene expression. The deficiency in PRC2 has a direct impact on a selected group of genes that is dominated by self-regulating transcription factors normally suppressed in these neurons. The age-dependent progressive transcriptional changes in PRC2-deficient neurons are associated with impaired neuronal function and survival and lead to the development of fatal neurodegenerative disorders in mice.
Polycomb repressive complex 2 (PRC2) silences genes responsible for neurodegeneration.
No sample metadata fields
View SamplesDefinitive hematopoiesis emerges during embryogenesis via an endothelial-to-hematopoietic transition. We attempted to induce this process in mouse fibroblasts by screening a panel of factors for hemogenic activity. We identified a combination of four transcription factors, Gata2, Gfi1b, cFos, and Etv6 that efficiently induces endothelial-like precursor cells with the subsequent appearance of hematopoietic cells. The precursor cells express a human CD34 reporter, Sca1 and Prominin1 within a global endothelial transcription program. Emergent hematopoietic cells possess nascent/specifying hematopoietic stem cell gene expression profiles and cell surface phenotypes. After transgene silencing and reaggregation culture, the specified cells generate hematopoietic colonies in vitro. Thus, we have shown that a simple combination of transcription factors is sufficient to induce a complex, dynamic and multi-step developmental program in vitro. These findings provide insights into the specification of definitive hemogenesis and a platform for future development of patient-specific stem/progenitor cells as well as more differentiated blood products. Overall design: mRNA-seq profiling on populations generated after transduction with Gata2, Gfi1b, cFos and Etv6 at day 20 and day 35.
Induction of a hemogenic program in mouse fibroblasts.
Specimen part, Subject, Time
View SamplesWhereas the cellular basis of the hematopoietic stem cell (HSC) niche in the bone marrow has been characterized, the nature of the fetal liver (FL) niche is not yet elucidated. We show that Nestin+NG2+ pericytes associate with portal vessels, forming a niche promoting HSC expansion. Nestin+NG2+ cells and HSCs scale during development with the fractal branching patterns of portal vessels, tributaries of the umbilical vein. After closure of the umbilical inlet at birth, portal vessels undergo a transition from Neuropilin-1+Ephrin-B2+ artery to EphB4+ vein phenotype, associated with a loss of peri-portal Nestin+NG2+ cells and emigration of HSCs away from portal vessels. These data support a model in which HSCs are titrated against a peri-portal vascular niche with a fractal-like organization enabled by placental circulation. Overall design: Characterization of the transcriptome of fetal liver and adult bone marrow niche using RNA-seq
Fetal liver hematopoietic stem cell niches associate with portal vessels.
Specimen part, Cell line, Subject
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