Tight regulation of hematopoietic stem cell (HSC) homeostasis is essential for life-long hematopoiesis, for preventing blood cancers and for averting bone marrow failure. The underlying mechanisms are incompletely understood. Here, we identify production of inositol-tetrakisphosphate (IP4) by inositoltrisphosphate 3-kinase B (ItpkB) as essential for HSC quiescence and function. Young ItpkB-/- mice accumulated phenotypic HSC and showed extramedullary hematopoiesis. ItpkB-/- HSC were less quiescent and proliferated more than wildtype controls. They downregulated quiescence and stemness associated mRNAs, but upregulated activation, oxidative metabolism, protein synthesis and lineage associated transcripts. Although they showed no significant homing defects, ItpkB-/- HSC had a severely reduced competitive long-term repopulating potential. Aging ItpkB-/- mice lost hematopoietic stem and progenitor cells and died with severe anemia. Wildtype HSC normally repopulated ItpkB-/- hosts, incidating a HSC-intrinsic ItpkB requirement. ItpkB-/- HSC had reduced cobblestone-area forming cell activity in vitro and showed increased stem-cell-factor activation of the phosphoinositide 3-kinase (PI3K) effector Akt, reversed by exogenous provision of the known PI3K/Akt antagonist IP4. They also showed transcriptome changes consistent with hyperactive Akt/mTOR signaling. Thus, we propose that ItpkB ensures HSC quiescence by limiting cytokine-induced PI3K signaling in HSC. Overall design: For each of 3 replicate ItpkB-/- or wt samples, we enriched Lin- cells from BM of 4 pooled age-matched mice with Rapidspheres (Stemcell Technologies), FACS-sorted =10,000 LSK CD34-CD150+CD48-Flk2- LT-HSC into lysis buffer and prepared RNA with RNeasy Micro kits (Quiagen). RNA sequencing was done using an Illumina HISeq Analyzer 2000, Casava v1.8.2 genome analyzer pipeline, TopHat v1.4.1/Bowtie2 genome alignment and Partek v6.6 mRNA annotation software. Statistical analyses were done with edgeR (Bioconductor package), excluding genes with false discovery rates >0.15, fold-change magnitudes =1.4 and log2(counts per million) =4 to avoid undefined values and the poorly defined log fold-changes for low counts close to 0. Unsupervised clustering of 441 significantly changed genes was done with dChip using rank correlation and a centroid linkage method. Scatter plots were generated in Spotfire. GSEA was performed with gene set permutation, using gene sets from MSigDB (www.broadinstitute.org/gsea/msigdb/index.jsp) or manually curated from, excluding genes without HUGO approved symbols
IP3 3-kinase B controls hematopoietic stem cell homeostasis and prevents lethal hematopoietic failure in mice.
No sample metadata fields
View SamplesThe cumulus cells niche that surrounds the oocyte is essential for its maturation and presumably for the oocyte to acquire its competence to confer pluripotency. The cells cultured from the human oocyte cumulus niche (hCC) could be used as feeders for the propagation of human pluripotent stem cells in vitro.
Cultured Cells from the Human Oocyte Cumulus Niche Are Efficient Feeders to Propagate Pluripotent Stem Cells.
Specimen part
View SamplesWe used microarrays to detail transcriptional changes in cultured human smooth muscle cells in response to acute and chronic 2-methoxyestradiol treatment
2-Methoxyestradiol blocks the RhoA/ROCK1 pathway in human aortic smooth muscle cells.
No sample metadata fields
View SamplesDirect reprogramming of human fibroblasts to a pluripotent state has been achieved through ectopic expression of the transcription factors OCT4, SOX2, and either cMYC and KLF4 or NANOG and LIN28. Little is known, however, about the mechanisms by which reprogramming occurs, which is in part limited by the low efficiency of conversion. To this end, we sought to create a doxycycline-inducible lentiviral system to convert primary human fibroblasts and keratinocytes into human induced pluripotent stem (hiPS) cells. hiPS cells generated with this system were molecularly and functionally similar to human embryonic stem (hES) cells, demonstrated by gene expression profiles, DNA methylation status, and differentiation potential. While expression of the viral transgenes was required for several weeks in fibroblasts, we found that 10 days was sufficient for the reprogramming of keratinocytes, suggesting that the kinetics of reprogramming are cell-type dependent. Using our inducible system, we developed a strategy to induce hiPS cell formation at high frequency by generating differentiated cells that contain the viral transgenes in a pattern that enables successful induction of pluripotency. Upon addition of doxycycline to differentiated hiPS-derived cells, we obtained secondary hiPS cells at a frequency at least 100-fold greater than the initial conversion. The ability to reprogram cells with high efficiency provides a unique platform to dissect the underlying molecular and biochemical processes that accompany nuclear reprogramming.
A high-efficiency system for the generation and study of human induced pluripotent stem cells.
No sample metadata fields
View SamplesAnamniotes, rodents and man maintain a pool of adult neural stem cells around the central canal in the spinal cord representing an attractive cellular source for endogenous repair. Cell diversity and genes specific for this niche are still ill-defined in mammals. To identify genes specifically expressed in the niche, we microdissected (with laser) the central canal region and the adjacent tissue in human and mice adult tissues. Total RNA was isolated and used to probe affymetrix microarrays
RNA Profiling of the Human and Mouse Spinal Cord Stem Cell Niches Reveals an Embryonic-like Regionalization with MSX1<sup>+</sup> Roof-Plate-Derived Cells.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.
Cell line
View SamplesTranscriptome analysis of 130 breast cancer samples (41 TNBC; 30 Her2; 30 Luminal B and 29 Luminal A), 11 normal breast tissue samples and 14 TNBC cell lines.
Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.
Cell line
View SamplesTranscriptome analysis of 130 breast cancer samples (41 TNBC; 30 Her2; 30 Luminal B and 29 Luminal A), 11 normal breast tissue samples and 14 TNBC cell lines.
Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.
Cell line
View SamplesWe analyzed the transcriptome of two different triple negative breast cancer (TNBC) cell lines to define a comprehensive list of Wnt target genes. Cells were treated with Wnt3a for 6h, 12h or 24h. We found up-regulated and down-regulated genes in response to Wnt3a treatment. They are involved in the Wnt pathway itself, and also in TGF, p53 and Hedgehog pathways. Thorough characterization of these novel potential Wnt target genes may reveal new regulators of the canonical Wnt pathway. The comparison of our list of Wnt target genes with those published in other cellular contexts confirms the notion that Wnt target genes are tissue-, cell line- and treatment-specific.
Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.
Cell line
View SamplesThe tumor suppressor genes EAF2 and p53 are frequently dysregulated in prostate cancers. Recently, we reported that concurrent p53 nuclear staining and EAF2 downregulation were associated with high Gleason score. Combined loss of EAF2 and p53 in a murine model induced prostate tumors, and concurrent knockdown of EAF2 and p53 in prostate cancer cells enhanced proliferation and migration, further suggesting that EAF2 and p53 could functionally interact in the suppression of prostate tumorigenesis. Here, RNA-seq analyses identified differentially regulated genes in response to concurrent knockdown of p53 and EAF2. Several of these genes were associated with the STAT3 signaling pathway, and this was verified by significantly increased p-STAT3 immunostaining in the Eaf2-/-p53-/- mouse prostate. STAT3 knockdown abrogated the stimulation of C4-2 cell proliferation by concurrent knockdown of EAF2 and p53. Furthermore, immunostaining of p-STAT3 was increased in human prostate cancer specimens with EAF2 downregulation and/or p53 nuclear staining. Our findings suggest that simultaneous inactivation of EAF2 and p53 can act to activate STAT3 and drive prostate tumorigenesis. Overall design: C4-2 prostate cancer cells treated with siEAF2 and/or sip53 mRNA profiles were generated by deep sequencing, using Illumina HiSeq 2000.
EAF2 and p53 Co-Regulate STAT3 Activation in Prostate Cancer.
Specimen part, Cell line, Subject
View Samples