In skeletal muscle, the pattern of electrical activity regulates the expression of proteins involved in synaptic transmission, contraction and metabolism. Disruptions in electrical activity, resulting from prolonged bed-rest, cast-immobilization or trauma, inevitably lead to muscle atrophy. The mechanisms that regulate muscle atrophy are poorly understood, but it seems likely that changes in gene expression play a key role in initiating and maintaining a muscle atrophy program. Previously, we found that Runx1, a transcription factor previously termed AML1, was substantially induced in muscle following denervation. More recently, we sought to determine whether this increase in Runx1 expression may be causally related to the morphological changes in skeletal muscle that accompany muscle disuse, notably muscle atrophy. We found that Runx1 is indeed required to sustain muscle and to minimize atrophy following denervation. Experiments described here are designed to identify the genes that are regulated by Runx1 in skeletal muscle with the particular goal of identifying genes that regulate muscle atrophy.
Runx1 prevents wasting, myofibrillar disorganization, and autophagy of skeletal muscle.
No sample metadata fields
View SamplesAlthough glucocorticoids (GCs) are known to exert numerous effects in the hippocampus, their chronic regulatory functions remain poorly understood. Moreover, evidence is inconsistent regarding the longstanding hypothesis that chronic GC exposure promotes brain aging/Alzheimer's disease. Here, we adrenalectomized male F344 rats at 15-months-of-age, maintained them for 3 months with implanted corticosterone (CORT) pellets producing low or intermediate (glucocorticoid-receptor (GR)-activating) blood levels of CORT, and performed microarray/pathway analyses in hippocampal CA1. We defined the chronic GC-dependent transcriptome as 393 genes that exhibited differential expression between Intermediate- and Low-CORT groups. Short-term CORT (4 days) did not recapitulate this transcriptome. Functional processes/pathways overrepresented by chronic CORT-upregulated genes included learning/plasticity, differentiation, glucose metabolism and cholesterol biosynthesis, whereas processes overrepresented by CORT-downregulated genes included inflammatory/immune/glial responses and extracellular structure. These profiles indicate that GCs chronically activate neuronal/metabolic processes while coordinately repressing a glial axis of reactivity/inflammation. We then compared the GC-transcriptome with a previously-defined hippocampal aging transcriptome, revealing a high proportion of common genes. Although CORT and aging moved expression of some common genes in the same-direction, the majority were shifted in opposite directions by CORT and aging (e.g., glial inflammatory genes downregulated by CORT are upregulated with aging). These results contradict the hypothesis that GCs simply promote brain aging, and also suggest that the opposite-direction shifts during aging reflect resistance to CORT regulation. Therefore, we propose a new model in which aging-related GC resistance develops in some target pathways while GC overstimulation develops in others, together generating much of the brain aging phenotype.
Glucocorticoid-dependent hippocampal transcriptome in male rats: pathway-specific alterations with aging.
Sex, Age, Specimen part
View SamplesThis study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis.
Mechanisms of Amplified Arteriogenesis in Collateral Artery Segments Exposed to Reversed Flow Direction.
Specimen part
View SamplesNumerous mechanisms to support cells under conditions of transient nutrient starvation have been described. The tumor suppressor protein p53 can contribute to the adaptation of cells to metabolic stress through various mechanisms that may help cancer cell survival in nutrient limiting conditions. We show here that p53 helps cancer cells to survive glutamine starvation by promoting the expression of SLC1A3, an aspartate/glutamate transporter that allows the utilization of aspartate to support cells in the absence of extracellular glutamine. Under glutamine deprivation, SLC1A3 expression maintains electron transport chain and tricarboxylic acid cycle activity, promoting de novo glutamate, glutamine and nucleotide synthesis to rescue cell viability. Tumor cells with high levels of SLC1A3 expression are resistant to glutamine starvation and SLC1A3 depletion retards the growth of these cells in vitro and in vivo, suggesting a therapeutic potential for SLC1A3 inhibition. Overall design: We quantify transcription via high throughput RNA sequencing in HCT116 cells (WT1 and WT2 clones) grown in complete medium (CM) or in glutamine-free medium (GD) for 48 hours.
A Role for p53 in the Adaptation to Glutamine Starvation through the Expression of SLC1A3.
Specimen part, Cell line, Subject
View SamplesBackground: Mycobacterium tuberculosis infection is a leading cause of infectious death worldwide. Gene-expression microarray studies profiling the blood transcriptional response of tuberculosis (TB) patients have been undertaken in order to better understand the host immune response as well as to identify potential biomarkers of disease. To date most of these studies have focused on pulmonary TB patients with gene-expression profiles of extra-pulmonary TB patients yet to be compared to those of patients with pulmonary TB or sarcoidosis.
The Transcriptional Signature of Active Tuberculosis Reflects Symptom Status in Extra-Pulmonary and Pulmonary Tuberculosis.
Sex, Age, Specimen part, Disease, Disease stage, Race
View SamplesWe profiled total mRNA of pancreas and kidney tissues of 3 different strains (p53-null; In4a/Arf-null and WT) of reprogrammable mouse lines (they all express OCT4, SOX2, KLF4, C-MYC under the control of a tetracycline promoter, activated by doxycycline) Overall design: 5 mice of each genotype were treated with doxycycline to induce the expression of the reprogramming factors, they were sacrificed and total mRNA was extracted from pancreas and kidney tissues (we mapped >24M reads per sample)
Tissue damage and senescence provide critical signals for cellular reprogramming in vivo.
Specimen part, Cell line, Subject
View SamplesGraft versus host disease (GVHD) is the most common complication of hematopoietic stem cell transplant (HCT). However, our understanding of the molecular pathways that cause this disease remains incomplete, leading to inadequate treatment strategies. To address this, we measured the gene expression profile of non-human primate (NHP) T cells during acute GVHD. In this study we specifically interrogated the transcriptional signatures of animals treated with FR104 monotherapy and FR104/Sirolimus combination therapy
Combined OX40L and mTOR blockade controls effector T cell activation while preserving T<sub>reg</sub> reconstitution after transplant.
Specimen part, Subject
View SamplesGraft versus host disease (GVHD) is the most common complication of hematopoietic stem cell transplant (HCT). However, our understanding of the molecular pathways that cause this disease remains incomplete, leading to inadequate treatment strategies. To address this, we measured the gene expression profile of non-human primate (NHP) T cells during acute GVHD. In this study we specifically interrogated the transcriptional signatures of animals treated with KY1005 monotherapy and KY1005/Sirolimus combination therapy
Combined OX40L and mTOR blockade controls effector T cell activation while preserving T<sub>reg</sub> reconstitution after transplant.
No sample metadata fields
View SamplesWe evaluated changes in mRNA stability and transcription using 4sU metabolic pulse labeling across a four hour time course following activation of Jurkat T cells with PMA and PHA Overall design: Measurement of total mRNA (T) and 4sU labeled mRNA (IP) in three biological replicates at five time points: prior to activation (U) and the first four hours after activation (1-4)
Functional coordination and HuR-mediated regulation of mRNA stability during T cell activation.
No sample metadata fields
View SamplesUsing RNA-seq, we characterize the global AS regulation of the eight Drosophila SR protein family members Overall design: RNA-seq experiments on two replicate samples from 8 individual SR protein knockdown (exptGroup=S), two replicates of simultaneous SR protein knockdown (XL6:B52 & SC35:B52) (exptGroup=D). Each exptGroup includes duplicate of its own non-specific (NS) controls.
SR proteins control a complex network of RNA-processing events.
Specimen part, Subject
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