Recently, we have shown that disturbed flow caused by partial ligation of mouse carotid artery rapidly induces endothelial dysfunction and atherosclerosis within two weeks. To understand the molecular mechanisms by which disturbed flow induces atherosclerosis, we carried out genome-wide microarray study using endothelial RNAs isolated from the flow-disturbed left and the contralateral right common carotid artery (LCA and RCA) in C57BL/6 mice.
Discovery of novel mechanosensitive genes in vivo using mouse carotid artery endothelium exposed to disturbed flow.
Sex, Specimen part, Time
View SamplesBody size varies enormously among mammalian species. In small mammals, body growth is typically suppressed rapidly, within weeks, whereas in large mammals, growth is suppressed slowly, over years, allowing for a greater adult size. We recently reported evidence that body growth suppression in rodents is caused in part by a juvenile genetic program that occurs in multiple tissues simultaneously and involves the downregulation of a large set of growth-promoting genes. We hypothesized that this genetic program is conserved in large mammals but that its time course is evolutionarily modulated such that it plays out more slowly, allowing for more prolonged growth. Consistent with this hypothesis, using expression microarray analysis, we identified a set of genes that are downregulated with age in both juvenile sheep kidney and lung. This overlapping gene set was enriched for genes involved in cell proliferation and growth and showed striking similarity to a set of genes downregulated with age in multiple organs of the juvenile mouse and rat, indicating that the multiorgan juvenile genetic program previously described in rodents has been conserved in the 80 million years since sheep and rodents diverged in evolution. Using microarray and real-time PCR, we found that the pace of this program was most rapid in mice, more gradual in rats, and most gradual in sheep. The findings support the hypothesis that a growth-regulating genetic program is conserved among mammalian species but that its pace is modulated to allow more prolonged growth and therefore greater adult body size in larger mammals.
Evolutionary conservation and modulation of a juvenile growth-regulating genetic program.
Specimen part
View SamplesGeneration of human fibroblast-derived hepatocytes capable of extensive proliferation, as evidenced by significant liver repopulation of mice. Unlike current protocols for deriving hepatocytes from human fibroblasts, ours did not generate iPSCs, but shortcut reprogramming to pluripotency to generate an induced multipotent progenitor cell (iMPC) stage from which endoderm progenitor cells (iMPC-EPCs) and subsequently hepatocytes (iMPC-Heps) could be efficiently differentiated. After transplantation into an immune-deficient mouse model of human liver failure, iMPC-Heps were able to engraft and proliferate, and acquired levels of hepatocyte function similar to adult hepatocytes.
Mouse liver repopulation with hepatocytes generated from human fibroblasts.
Specimen part
View SamplesHematopoietic stem cells (HSCs), which reside in bone marrow niches, are exposed to low levels of oxygen and follow an oxygen gradient throughout their differentiation. Hypoxia-inducible factors (HIFs) are the main factors regulating the cell response to oxygen variation. Recent studies using conditional knockout mouse models have unveiled a major role of HIF-1a in the maintenance of murine HSCs, however the role of HIF-2a is still unclear. Here, we show that knockdown of HIF-2a and to a much lower extent, HIF-1a impedes the long-term repopulating ability of human CD34+ umbilical cord blood derived cells. The defects observed in hematopoietic stem and progenitor cell (HSPC) function after HIF-2a knockdown was due to an increase in the production of reactive oxygen species (ROS), which increases the endoplasmic reticulum (ER) stress in HSPCs and triggers apoptosis by the activation of the unfolded-protein-response (UPR) pathway. Importantly, HIF-2a deregulation also resulted in a significant decrease of engraftment of human acute myeloid leukemia (AML) cells. Overall, our data demonstrates a key role of HIF-2a in the maintenance of human HSPCs and in the survival of primary AML cells.
HIF-2α protects human hematopoietic stem/progenitors and acute myeloid leukemic cells from apoptosis induced by endoplasmic reticulum stress.
Specimen part
View SamplesIn this study Panc-1 cells and BxPC-3 cells were cultured. The cells were harvested (untreated control 'cont') for RNA extraction, or treated for 3 hours with various exosomes preparations. The exosomes were collected from BJ human foreskin fibroblast culture supernatant without further processing (control exosomes or 'CE'), or engineered to contain scrambled siRNA ('scr') or KRASG12D siRNA ('iExo). Two or three distinct wells of cells were evaluated per treatment condition and assigned a well number (well -1, -2 or 3).
Generation and testing of clinical-grade exosomes for pancreatic cancer.
Cell line, Treatment
View SamplesThe cancer-risk associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long non-coding RNA CCAT2 in the highly amplified 8q24.21 region has been implicated in cancer predisposition, though causality has not been established. Here, using allele-specific CCAT2 transgenic mice, we demonstrate that CCAT2 overexpression leads to spontaneous myeloid malignancies. CCAT2 is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients. CCAT2 induces global deregulation of gene expression by downregulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel disease-specific RNA mutation (named DNA-to-RNA allelic imbalance, DRAI) at the SNP locus in MDS/MPN patients and CCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP and CCAT2 in myeloid malignancies.
Cancer-associated rs6983267 SNP and its accompanying long noncoding RNA <i>CCAT2</i> induce myeloid malignancies via unique SNP-specific RNA mutations.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The human primary hepatocyte transcriptome reveals novel insights into atorvastatin and rosuvastatin action.
Specimen part, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Developmental and evolutionary basis for drought tolerance of the Anopheles gambiae embryo.
No sample metadata fields
View SamplesIn order to examine the gene expression in the course of mosquito embryogenesis, microarray assays were performed on staged A. gambiae embryos, from fertilization to 52 hours of development (which is close to hatching at ~50 hours post-fertilization). RNA was extracted from staged embryos roughly every three hours after fertilization, and then hybridized to the A. gambiae transcriptome microarray.
Developmental and evolutionary basis for drought tolerance of the Anopheles gambiae embryo.
No sample metadata fields
View SamplesWith particular emphasis on interactions between cholesterol homeostasis and drug metabolism we investigate the transcriptome of human primary hepatocytes treated by two commonly prescribed cholesterol lowering drugs atorvastatin and rosuvastatin and by rifampicin that serves as an outgroup as well as a model substance for induction of nuclear receptor PXR.
The human primary hepatocyte transcriptome reveals novel insights into atorvastatin and rosuvastatin action.
Specimen part, Subject, Time
View Samples