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 SamplesTo better characterize the role of whole pericardial adipose tissue (PCAT) in the pathogenesis of disease, we performed a large-scale unbiased analysis of the transcriptional differences between pericardial and subcutaneous adipose tissue, analysing 53 microarrays across 19 individuals.
Pattern specification and immune response transcriptional signatures of pericardial and subcutaneous adipose tissue.
Specimen part, Subject
View SamplesClinical application of induced pluripotent stem (iPS) cells is limited by low efficiency of iPS derivation, and protocols that permanently modify the genome to effect cellular reprogramming. Moreover, safe and effective means of directing the fate of patient-specific iPS cells towards clinically useful cell types are lacking. Here we describe a simple, non-mutagenic strategy for reprogramming cell fate based on administration of synthetic mRNA modified to overcome innate anti-viral responses. We show that this approach can reprogram multiple human cell types to pluripotency with efficiencies that greatly surpass established protocols. We further show that the same technology can be used to efficiently direct the differentiation of RNA-induced pluripotent stem (RiPS) cells into terminally differentiated myogenic cells. Our method represents a safe, efficient strategy for somatic cell reprogramming and directing cell fates that has broad applicability for basic research, disease modeling and regenerative medicine.
Highly efficient reprogramming to pluripotency and directed differentiation of human cells with synthetic modified mRNA.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Programming human pluripotent stem cells into white and brown adipocytes.
Specimen part, Disease
View SamplesThe utility of human pluripotent stem cells as a tool for understanding disease and as a renewable source of cells for transplantation therapies is dependent on efficient differentiation protocols that convert these cells into relevant adult cell types. Here we report the robust and efficient differentiation of human pluripotent stem cells into adipocytes. We found that inducible expression of PPARG2 in pluripotent stem cell-derived mesenchymal progenitor cells programmed their development towards an adipocyte cell fate. Using this approach, multiple human pluripotent cell lines were differentiated into adipocytes with efficiencies of 85% to 90%. These pluripotent stem cell-derived adipocytes retained their identity independent of transgene expression, could be maintained in culture for several weeks, expressed mature markers, and exhibited mature functional properties such as lipid catabolism in response to a beta-adrenergic stimulus. Global transcriptional and lipid metabolomic analyses further confirmed the identity and maturity of these pluripotent stem cell-derived adipocytes.
Programming human pluripotent stem cells into white and brown adipocytes.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MLL-AF9 Expression in Hematopoietic Stem Cells Drives a Highly Invasive AML Expressing EMT-Related Genes Linked to Poor Outcome.
Specimen part
View SamplesTo address the impact of cellular origin on AML, we generated an inducible transgenic mouse model for MLL-AF9 driven leukemia. MLL-AF9 expression in long-term hematopoietic stem cells (LT-HSCs) in vitro resulted in unprecedented clonogenic growth and expression of genes involved in migration and invasion. In vivo, some LT-HSC-derived AMLs were particularly aggressive with extensive tissue infiltration, chemo-resistance and expression of genes related to epithelial-mesenchymal transition (EMT) in solid cancers. Knockdown of the EMT regulators Zeb1 and Tcf4 significantly reduced leukemic blast invasion. By classifying mouse and human leukemia according to Evi1/EVI1and Erg/ERG expression, reflecting aggressiveness and cell-of-origin and performing comparative transcriptomics we identified numerous EMT-related genes that were significantly associated with poor overall survival of AML patients. Overall design: RNA from FACS sorted bone marrow subpopulations was isolated, RNA-sequencing libraries were prepared and sequenced on an Illumina HiSeq 2000. Reads mapping to RefSeq transcripts were counted.
MLL-AF9 Expression in Hematopoietic Stem Cells Drives a Highly Invasive AML Expressing EMT-Related Genes Linked to Poor Outcome.
No sample metadata fields
View SamplesTo address the impact of cellular origin on AML, we generated an inducible transgenic mouse model for MLL-AF9 driven leukemia. MLL-AF9 expression in long-term hematopoietic stem cells (LT-HSCs) in vitro resulted in unprecedented clonogenic growth and expression of genes involved in migration and invasion. In vivo, some LT-HSC-derived AMLs were particularly aggressive with extensive tissue infiltration, chemo-resistance and expression of genes related to epithelial-mesenchymal transition (EMT) in solid cancers. Knockdown of the EMT regulators Zeb1 and Tcf4 significantly reduced leukemic blast invasion. By classifying mouse and human leukemia according to Evi1/EVI1and Erg/ERG expression, reflecting aggressiveness and cell-of-origin and performing comparative transcriptomics we identified numerous EMT-related genes that were significantly associated with poor overall survival of AML patients.
MLL-AF9 Expression in Hematopoietic Stem Cells Drives a Highly Invasive AML Expressing EMT-Related Genes Linked to Poor Outcome.
Specimen part
View Samples