Transplanting vascular endothelial cells (ECs) to support metabolism and express regenerative paracrine factors is a strategy to treat vasculopathies and to promote tissue regeneration. However, transplantation strategies have been challenging to develop because ECs are difficult to culture and little is known about how to sustain their vascular identity and direct them to form long-lasting new vessels or engraft into existing ones. We found that multiple non-vascular cell types transiently expressed EC markers after enforced expression of the transcription factors, Etv2, Erg, and Fli1. However, only mid-gestational amniotic cells could be converted to cells that maintained EC gene expression and proliferated in culture to yield billions of vascular cells. Even so, these converted cells performed sub-optimally in assays of EC function. We used constitutive Akt signaling to mimic the shear forces of the vascular environment and promote EC survival in an effort to correct the deficiencies of the converted cells. Akt signaling increased gene expression of EC morphogenesis genes, including Sox17, shifted the genomic targeting of Fli1 to favor nearby Sox consensus sites, and enhanced the in vivo vascular function of EC-like converted cells. Enforced expression of Sox17 was dispensable for broad EC gene activation, but indispensable for vascular engraftment and reperfusion of ischemic tissue. Our results identify a transcription factor network comprised of Ets and Sox17 factors that specifies and sustains endothelial cell fate and function. This work shows that the commonly used criterion of transcriptional similarity for cell conversion can fail to predict in vivo vascular function. Our approach shows that stringent functional testing in vitro and in vivo is necessary to validate engineered endothelial cell grafts. Overall design: Transcriptome sequencing of endothelial cells and amniotic cells
Sox17 drives functional engraftment of endothelium converted from non-vascular cells.
Specimen part, Subject
View SamplesEndothelial cells from nine steady state tissues and two regenerating tissues (bone marrow and liver) were intravitally labeld, isolated via flow sorting, and immediately processed for RNA extraction.
Molecular signatures of tissue-specific microvascular endothelial cell heterogeneity in organ maintenance and regeneration.
Sex, Specimen part, Treatment, Time
View SamplesThe simultaneous genotyping of tens of thousands of SNP using SNP microarrays is a very important tool that is revolutionizing genetics and molecular biology. In this work, we present a new application of this technique by using it to assess chromatin immunoprecipitation (CHIP) as a means to assess the multiple genomic locations bound by a protein complex recognized by an antibody. We illustrate the use of this technique with an analysis of the change in histone H4 acetylation, a marker of open chromatin and transcriptionally active genomic regions, which occur during the differentiation of human myoblasts into myotubes. Our results are validated by the observation of a significant correlation between the histone modifications detected and the expression of the nearby genes, as measured by DNA microarrays.
ChIP on SNP-chip for genome-wide analysis of human histone H4 hyperacetylation.
No sample metadata fields
View SamplesGene expression was determined for both myotubes and myoblasts using Affymetrix HG-U133 A/B arrays.
ChIP on SNP-chip for genome-wide analysis of human histone H4 hyperacetylation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration.
Sex, Specimen part
View SamplesThe thymus is extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood and this capacity diminishes considerably with age. To identify alternate regeneration pathways in the thymus, we performed an unbiased transcriptome analysis of the non-hematopoietic (CD45-) stromal cell compartment of the thymus, which is less sensitive to thymic damage compared to the CD45+ hematopoietic compartment.
Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration.
Sex, Specimen part
View SamplesThe thymus is extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood and this capacity diminishes considerably with age. To identify alternate regeneration pathways in the thymus, we performed an unbiased transcriptome analysis of the non-hematopoietic (CD45-) stromal cell compartment of the thymus, which is less sensitive to thymic damage compared to the CD45+ hematopoietic compartment.
Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration.
Sex, Specimen part
View SamplesRenal hypoxia is widespread in acute kidney injury (AKI) of various aetiologies. Hypoxia adaptation, conferred through the hypoxia-inducible factor (HIF), appears to be insufficient. Here we show that HIF activation in renal tubules through Pax8-rtTA-based inducible knockout of von Hippel-Lindau protein (VHL-KO) protects from rhabdomyolysis-induced AKI. In this model, histological observations indicate that injury mainly affects proximal convoluted tubules, with 5% necrosis at d1 and 40% necrosis at d2. HIF-1alpha up-regulation in distal tubules reflects renal hypoxia. However, lack of HIF in proximal tubules suggests insufficient adaptation by HIF.
Tubular von Hippel-Lindau knockout protects against rhabdomyolysis-induced AKI.
Specimen part, Disease, Disease stage, Treatment
View SamplesWe probed the mechanism of cross-regulation of osmotic and heat stress responses by characterizing the effects of high osmolarity (0.3M vs. 0.0M NaCl) and temperature (43oC vs. 30oC) on the transcriptome of Escherichia coli K12 using E. coli Genome 2 Array (Affymetrix, Inc.). Independent array hybridizations were carried out for 3 biological replicates (independent cultures). Total RNA was extracted using a hot phenol-chloroform method. cDNA synthesis, fragmentation and labeling, and washing and scanning of E. coli GeneChip Arrays were performed according to the instructions of the manufacturer (Affymetrix Technical Manual, Affymetrix, Inc., USA). Labeled cDNA was hybridized to E. coli Genome 2 Array (Affymetrix, Inc.). Independent array hybridizations were carried out for 3 biological replicates (independent cultures) of each condition. A number of genes in the SoxRS and OxyR oxidative stress regulons were up-regulated by high osmolarity, high temperature, and/or by the combination of both stresses. This result could account for cross-protection of osmotic stress against oxidative stress. The trehalose biosynthetic genes were induced by both stresses, in accord with the proposed protective role of this disaccharide against thermal and oxidative damage.
Genome-wide transcriptional responses of Escherichia coli K-12 to continuous osmotic and heat stresses.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Adenosine-to-inosine RNA editing by ADAR1 is essential for normal murine erythropoiesis.
Sex, Specimen part
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