Direct 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 SamplesIn human cells, Staufen1 is double-stranded RNA-binding protein involved in several cellular functions including mRNA localization, translation and decay. We used a genome wide approach to identify and compare the mRNA targets of mammalian Staufen1. The mRNA content of Staufen1 mRNPs was identified by probing DNA microarrays with probes derived from mRNAs isolated from immunopurified Staufen-containing complexes following transfection of HEK293T cells with a Stau1-HA expressor. Our results indicate that 7% of the cellular RNAs expressed in HEK293T cells are found in Stau1-containing mRNPs. There is a predominance of mRNAs involved in cell metabolism, transport, transcription, regulation of cell processes and catalytic activity.
A genome-wide approach identifies distinct but overlapping subsets of cellular mRNAs associated with Staufen1- and Staufen2-containing ribonucleoprotein complexes.
No sample metadata fields
View SamplesIn human cells, Staufen2 is a double-stranded RNA-binding protein involved in several cellular functions. Although 51% identical to Staufen1, these proteins are nevertheless found in different RNA particles. In addition, differential splicing events generate Staufen2 isoforms that only differ at their N-terminal extremities. We used a genome wide approach to identify and compare the mRNA targets of mammalian Staufen2 isoforms. The mRNA content of Staufen mRNPs was identified by probing DNA microarrays with probes derived from mRNAs isolated from immunopurified Staufen2-containing complexes following transfection of HEK293T cells with Stau2-HA (59kDa) or Stau2-HA (62kDa) expressors. Our results indicate that 11% of the cellular RNAs expressed in HEK293T cells are found in Stau2-containing mRNPs. There is a predominance of mRNAs involved in cell metabolism, transport, transcription, regulation of cell processes and catalytic activity.
A genome-wide approach identifies distinct but overlapping subsets of cellular mRNAs associated with Staufen1- and Staufen2-containing ribonucleoprotein complexes.
No sample metadata fields
View SamplesNext Generation Sequencing technologies have enabled de novo gene fusion discovery that could reveal candidates with therapeutic significance in cancer. Here we present an open-source software package, ChimeraScan, for the discovery of chimeric transcription between two independent transcripts. Overall design: Three cancer cell lines with known gene fusions
ChimeraScan: a tool for identifying chimeric transcription in sequencing data.
No sample metadata fields
View SamplesResearch shows that mindfulness practice can alter the expression of genes associated with energy metabolism, telomere maintenance, inflammatory and stress response. The aim of this study was to determine if mindfulness awareness practice (MAP) or health education program (HEP) might reverse cognitive impairment and/or prevent further cognitive decline in 60 subjects (aged 60-90). We investigated the gene expression changes in subject with mild cognitive impairment randomized to either group after 9 months.
Dataset on gene expression in the elderly after Mindfulness Awareness Practice or Health Education Program.
Sex, Treatment, Race
View SamplesThe generation of induced pluripotent stem cells (iPSCs) from differentiated cells following forced expression of Oct4, Klf4, Sox2 and c-Myc (OKSM) is slow and inefficient, suggesting that transcription factors have to overcome somatic barriers that resist cell fate change. Here, we performed an ubiased serial shRNA enrichment screen to identify novel repressors of somatic cell reprogramming into iPSCs. This effort uncovered the sumoylation effector protein Sumo2 as one of the strongest roadblocks to iPSC formation. Depletion of Sumo2 both enhances and accelerates reprogramming, yielding transgene-independent, chimera-competent iPSCs after as little as 36 hours of OKSM expression. We further show that the Sumo2 pathway acts independently of exogenous c-Myc expression and in parallel with small molecule enhancers of reprogramming. Critically, suppression of SUMO2 also promotes the generation of human iPSCs. Together, our results reveal sumoylation as a crucial post-transcriptional mechanism that resists the acquisition of pluripotency from fibroblasts using defined factors.
A Serial shRNA Screen for Roadblocks to Reprogramming Identifies the Protein Modifier SUMO2.
Sex, Specimen part, Time
View SamplesWe measured gene expression in the adrenal glands of the Spontaneously Hypertensive Rat (SHR) and Wistar-Kyoto rat (WKY) using Affymetrix RG-U34A GeneChips. All rats were aged-matched at 4-weeks. The rats were obtained from the colonies at the Univeristy of California San Diego, La Jolla, CA.
Common genetic mechanisms of blood pressure elevation in two independent rodent models of human essential hypertension.
No sample metadata fields
View SamplesWe performed Affymetrix MG-U74Av2 GeneChip experiements on mRNA from the adrenal glands of the BPH hypertensive and BPL hypotensive mouse strains. All mice were aged-matched at 5 weeks. We obtained the mice from Jackson Laboratories, Bar Harbor, ME.
Neuroendocrine transcriptome in genetic hypertension: multiple changes in diverse adrenal physiological systems.
No sample metadata fields
View SamplesMethods: RNA-seq libraries were prepared using the Illumina TruSeq RNA kit and the TrueSeq method was employed for mRNA enrichment. The libraries were quantified and samples were multiplexed in each lane of the flowcell. Cluster generation was performed and then sequenced on the Illumina HiSeq1000 system. Reads were mapped on the Human Genome Reference and normalized expression table was generated. Results: Among differentially expressed genes, 53 of them were up-regulated and 75 were down-regulated. Conclusions: Data demonstrate increased expression of genes associated with growth, development, and pro-survival in cardiac progenitors cultured under simulated microgravity compared with those cultured under standard gravity. Overall design: RNA-sequencing analysis was performed to compare global gene expression profiles of cells at differentiation day 8 under simulated microgravity vs. standard gravity.
Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells.
Specimen part, Subject
View SamplesTo better understand human spermatogonial stem cells (SSCs), we profiled their transciptome and epigenome, which revealed the mechanism how human SSCs regulates their self-renewal versus differentiation dermination, as well as how latent pluripotency is established in human SSCs. Remarkly, we discovered signaling pathways (e.g. LIF, BMP, WNT) that differentially regulated self-renewal vesus differentiation in SSCs. We also discovered that SSCs repress core pluripotent factors (Sox2, Pou5f1 and Nanog) yet activate ancillary factors (e.g. Klf4, Mbd3, Tcf3, Sall4) transcriptionally and epigenetically. Overall design: Using SSEA4 as self-renewal marker and Kit as differentiating marker, we isolated self-renewal and differentiation SSCs by magnetic antibody cell sorting (MACS). SSEA4+ or Kit+ cells were loaded into 5-10 µm integrated fluidic circuits (IFCs) using Fluidigm C1 instrument. Single cells in IFCs were lysed and total RNA was harvested for polyadenylation selection, reverse transcription and PCR amplification. Library constructions were performed according to Fluidigm Library preparation with Nextera XT protocol and sequenced on a 50-cycle single end run.
Chromatin and Single-Cell RNA-Seq Profiling Reveal Dynamic Signaling and Metabolic Transitions during Human Spermatogonial Stem Cell Development.
Specimen part, Subject
View Samples