OBJECTIVE: To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR). BACKGROUND: Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we show how short-term CR protects the mouse heart from ischemia. METHODS: Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL) diet with free access to regular chow, or CR, receiving 30% less food over a period of 7 days (d), prior to myocardial infarction (MI) via permanent coronary ligation. Prior to MI (d8), the left ventricles (LV) of AL and CR mice were collected for Western blot, DNA and microRNA (miR) analyses. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI. RESULTS: This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.52.4% vs. 26.61.7%, N=10/group; P=0.01). cDNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM). Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38). CONCLUSIONS: Short-term CR for only 7d represents a preconditioning strategy that limits infarct size. It is associated with a unique gene and miR signature, including the activation of specific pro-survival kinases. These findings may have implications for therapeutic use of short-term CR. .
Cardioprotective Signature of Short-Term Caloric Restriction.
Sex, Specimen part
View SamplesThe mammalian brain is complex, with multiple cell types performing a variety of diverse functions, but exactly how each cell type is affected in aging remains largely unknown. Here we performed a single-cell transcriptomic analysis of young and old mouse brains. We provide comprehensive datasets of aging-related genes, pathways and ligand–receptor interactions in nearly all brain cell types. Our analysis identified gene signatures that vary in a coordinated manner across cell types and gene sets that are regulated in a cell-type specific manner, even at times in opposite directions. These data reveal that aging, rather than inducing a universal program, drives a distinct transcriptional course in each cell population, and they highlight key molecular processes, including ribosome biogenesis, underlying brain aging. Overall, these large-scale datasets provide a resource for the neuroscience community that will facilitate additional discoveries directed towards understanding and modifying the aging process. Overall design: Total of 16 mice brains with raw data for 50,212 single cells and processed data for 37,089 single cells
Single-cell transcriptomic profiling of the aging mouse brain.
Specimen part, Subject
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miR-126 Regulates Distinct Self-Renewal Outcomes in Normal and Malignant Hematopoietic Stem Cells.
Specimen part, Cell line, Treatment
View SamplesIn acute myeloid leukemia (AML), leukemia stem cells (LSCs) play a central role in disease progression and recurrence due to their intrinsic capacity for self-renewal and chemotherapy resistance. Whereas epigenetic regulation balances normal blood stem cell self-renewal and fate decisions, mutation and dysregulation of epigenetic modifiers are now considered fundamental to leukemia initiation and progression. Alterations in miRNA function represent a non-canonical epigenetic mechanism influencing malignant hematopoiesis; however, the function of miRNA in LSC remains undetermined. Here we show that miRNA profiling of fractionated AML populations defines an LSC-specific signature that is highly predictive of patient survival. Gain-of-function genetic analysis demonstrated that miR-126 restrained cell cycle progression, prevented LSC differentiation, and increased LSC self-renewal. miR-126 promoted chemo-resistance, preserving LSC quiescence in part through suppression of the G0-to-G1 gatekeeper, CDK3. Thus, in AML, miRNAs influence patient outcome through post-transcriptional regulation of stemness programs in LSC.
miR-126 Regulates Distinct Self-Renewal Outcomes in Normal and Malignant Hematopoietic Stem Cells.
Specimen part, Cell line, Treatment
View SamplesGene expression (mRNA) profiling of human ependymomas
Delineation of two clinically and molecularly distinct subgroups of posterior fossa ependymoma.
Sex, Age, Specimen part
View SamplesTo obtain comprehensive information on 17beta-estradiol (E2) sensitivity of genes that are inducible or suppressible by this hormone, we designed a method that determines ligand sensitivities of large numbers of genes using DNA microarray and a set of simple Perl computer scripts implementing the standard metric statistics, and employed it to characterize effects of low (0-100 pM) concentrations of E2 on the transcriptome profile of MCF7/BUS human breast cancer cells, whose E2 dose-dependent growth curve saturated with 100 pM E2. Evaluation of changes in mRNA expression for all genes covered by the DNA microarray indicated that, at a very low concentration (10 pM), E2 suppressed 3~5 times larger numbers of genes than it induced, whereas at higher concentrations (30-100 pM) it induced 1.5~2 times more genes than it suppressed. Using clearly defined statistical criteria, E2-inducible genes were categorized into several classes based on their E2 sensitivities. This approach of hormone sensitivity analysis revealed that expression of two previously reported E2-inducible autocrine growth factors, TGF-? and SDF-1, was not affected by 100 pM and lower concentrations of E2 but strongly enhanced by 10 nM E2, which was far higher than the concentration that saturated the E2 dose-dependent growth curve of MCF7/BUS cells. These observations suggested that biological actions of E2 are derived from expression of multiple genes whose E2 sensitivities differ significantly and, hence, dependent on the E2 concentration especially when it is lower than the saturating level, emphasizing the importance of characterizing the ligand dose-dependent aspects of E2 actions. (paper abstract)
Global analysis of ligand sensitivity of estrogen inducible and suppressible genes in MCF7/BUS breast cancer cells by DNA microarray.
No sample metadata fields
View SamplesTranscriptome analysis of MCF-7 cells exposed for 48 hours to various concentrations of xenoestrogen chemicals.
Expressomal approach for comprehensive analysis and visualization of ligand sensitivities of xenoestrogen responsive genes.
Cell line
View SamplesTranscriptomes of mouse E12.5 primordial germ cells (PGCs), primordial germ cell-like cells (PGCLCs) isolated from 6-day culture embryoid bodies, and the precursor pluripotent stem cells [embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)] and epiblast-like cells (EpiLCs)
Erasure of DNA methylation, genomic imprints, and epimutations in a primordial germ-cell model derived from mouse pluripotent stem cells.
Sex, Specimen part
View SamplesEmergence of antiestrogen-resistant cells in MCF-7 cells during suppression of estrogen signaling is a widely accepted model of acquired breast cancer resistance to endocrine therapy. To obtain insight into the genomic basis of endocrine therapy resistance, we characterized MCF-7 monoclonal sublines that survived 21-day exposure to tamoxifen (T-series sublines) or fulvestrant (F-series sublines) and sublines unselected by drugs (U-series). All T/F-sublines were resistant to the cytocidal effects of both tamoxifen and fulvestrant. However, their responses to the cytostatic effects of fulvestrant varied greatly, and their remarkably diversified morphology showed no correlation with drug resistance. mRNA expression profiles of the U-sublines differed significantly from those of the T/F-sublines, whose transcriptomal responsiveness to fulvestrant was largely lost. A set of genes strongly expressed in the U-sublines successfully predicted metastasis-free survival of breast cancer patients. Most T/F-sublines shared highly homogeneous genomic DNA aberration patterns that were distinct from those of the U-sublines. Genomic DNA of the U-sublines harbored many aberrations that were not found in the T/F-sublines. These results suggest that the T/F-sublines are derived from a common monoclonal progenitor that lost transcriptomal responsiveness to antiestrogens as a consequence of genetic abnormalities many population doublings ago, not from the antiestrogen-sensitive cells in the same culture during the exposure to antiestrogens. Thus, the apparent acquisition of antiestrogen resistance by MCF-7 cells reflects selection of preexisting drug-resistant subpopulations without involving changes in individual cells. Our results suggest the importance of clonal selection in endocrine therapy resistance of breast cancer.
Antiestrogen-resistant subclones of MCF-7 human breast cancer cells are derived from a common monoclonal drug-resistant progenitor.
Specimen part, Cell line, Treatment
View SamplesWe have found that thyroid hormones (THs), acting as soluble integrin avß3 ligands, activate growth-related signaling pathways in T-cell lymphomas (TCL). Specifically, TH-activated avß3 integrin signaling promotes TCL proliferation and angiogenesis, in part, via the up-regulation of VEGF. Overall design: CUTLL1 cells were treated with T3- and T4-bound agarose or agarose alone for 24hrs. Total RNA was harvested from cells and used for expression profiling via RNA-seq.
Integrin αvβ3 acting as membrane receptor for thyroid hormones mediates angiogenesis in malignant T cells.
No sample metadata fields
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