Bone adaptation to mechanical loading is regulated via signal transduction by mechano-sensing osteocytes. Mineral-embedded osteocytes experience strain-induced interstitial fluid flow and fluid shear stress, and broad shifts in gene expression are key components in the signaling pathways that regulate bone turnover. RNA sequencing analysis, or RNA-Seq, enables more complete characterization of mechano-sensitive transcriptome regulation than previously possible. We hypothesized that RNA-Seq of osteocytic MLO-Y4 cells reveals both expected and novel gene transcript regulation in cells previously fluid flowed and analyzed using gene microarrays (Govey et al., J Biomech, 2014). MLO-Y4 cells were flowed for 2 h with 1 Pa oscillating fluid shear stress and post-incubated 2 h. RNA-Seq of original samples detected 58 fluid flow-regulated gene transcripts (p-corrected<0.05) versus 65 transcripts detected by microarray. However, RNA-Seq demonstrated greater dynamic range, with all 58 transcripts >1.5 fold-change whereas 10 of 65 met this cut-off by microarray. Analyses were complimentary in patterns of regulation, though only 6 transcripts were significant in both analyses: Cxcl5, Cxcl1, Zc3h12a, Ereg, Slc2a1, and Egln1. As part of a broad inflammatory response inferred by gene ontology analyses, we again observed greatest up-regulation of inflammatory C-X-C motif chemokines, and newly implicated HIF-1? and AMPK signaling pathways. Importantly, we detected both expected mechano-sensitive transcripts (e.g. Nos2, Ptgs2, Ccl7) and transcripts not previously identified as mechano-sensitive, e.g. Ccl2. We found RNA-Seq advantageous over microarrays because of its ability to analyze unbiased estimation of gene expression, informing our understanding of osteocyte signaling. Overall design: Osteocyte-like MLO-Y4 cells were subjected to 2 hours of 10 dyn/cm^2 oscillating fluid flow in parallel-plate fluid flow chambers and harvested for analysis after an additional 2 hours post-flow incubation in fresh medium. Parallel control samples from sham treated cells were also collected. Triplicate samples of both flow and non-flow control conditions were collected to analyze flow vs. non-flow gene transcript regulation.
Functional and structural characterization of osteocytic MLO-Y4 cell proteins encoded by genes differentially expressed in response to mechanical signals in vitro.
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View SamplesThe CREB binding protein inhibitor ICG-001 suppresses pancreatic cancer growth
The CREB-binding protein inhibitor ICG-001 suppresses pancreatic cancer growth.
Cell line, Treatment
View SamplesMetabolic production of acetyl-CoA has been linked to histone acetylation and gene regulation, however the mechanisms are largely unknown. We show that the metabolic enzyme acetyl-CoA synthetase 2 (ACSS2) is a critical and direct regulator of histone acetylation in neurons and of long-term mammalian memory. We observe increased nuclear ACSS2 in differentiating neurons in vitro. Genome-wide, ACSS2 binding corresponds with increased histone acetylation and gene expression of key neuronal genes. These data indicate that ACSS2 functions as a chromatin-bound co-activator to increase local concentrations of acetyl-CoA and to locally promote histone acetylation for transcription of neuron-specific genes. Remarkably, in vivo attenuation of hippocampal ACSS2 expression in adult mice impairs long-term spatial memory, a cognitive process reliant on histone acetylation. ACSS2 reduction in hippocampus also leads to a defect in upregulation of key neuronal genes involved in memory. These results reveal a unique connection between cellular metabolism and neural plasticity, and establish a link between generation of acetyl-CoA and neuronal chromatin regulation. Overall design: Global survey of gene expression in CAD cells and differentiated CAD neurons following lentiviral knockdown of ACSS2 or ATP citrate lyase (ACL) (and control = scramble hairpin); survey of hippocampal gene expression changes associated with retrieval of fear memory, after ACSS2-AAV knockdown or in EGFP-AAV control (comparison of 0h vs. 1h post-memory retrieval).
Acetyl-CoA synthetase regulates histone acetylation and hippocampal memory.
Specimen part, Cell line, Treatment, Subject, Time
View SamplesIn this study, time dependent genome wide lung mRNA profiling changes were assessed using C57BL/6J and A/J mice. Through comprehensive bioinformatics and functional genomics analyses, we identified both temporal and strain dependent gene expression patterns, systemically mapped key regulators, bioprocesses, and transcriptional networks controlling lung maturation, providing the basis for new therapeutic strategies to enhance lung function in preterm infants.
Transcriptional programs controlling perinatal lung maturation.
Specimen part, Time
View SamplesThere are an estimated 21million diabetics in the United States and 150 million diabetics worldwide. The World Health Organization anticipates that these numbers will double in the next 20 years. Metabolic syndrome is a well recognized set of symptoms that increases a patients risk of developing diabetes. Insulin resistance is a factor in both metabolic syndrome and Type 2 diabetes. It is characterized by decreased insulin stimulated glucose uptake in peripheral tissues, decreased adiponectin levels, increased adipocyte FFA and cytokine production, and increased insulin and hepatic glucose output. Prevention or reversal of insulin resistance should serve as an important strategy in addressing the growing health concerns posed by the Diabetes epidemic. While increased adiposity is associated with insulin resistance, the role of the cell types present within adipose (adipocytes, pre-adipocytes, endothelial cells, macrophages, fibroblasts, leukocytes and smooth muscle cells) in insulin resistance is unclear. In an effort to begin dissection of this question, we examined the transcriptional response of the buoyant and non-buoyant fractions isolated from insulin sensitive or TNF induced insulin resistant hMSC derived adipocytes before and after treatment with insulin.
Genome-wide profiling of H3K56 acetylation and transcription factor binding sites in human adipocytes.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative survival-based molecular profiling of human pancreatic cancer.
Specimen part, Disease, Disease stage
View SamplesTo perform an integrative profile of human pancreatic cancer (PDAC) to identify prognosis-significant genes and their related pathways.
Integrative survival-based molecular profiling of human pancreatic cancer.
Specimen part, Disease, Disease stage
View SamplesCyclooxygenase-2 (COX-2) is upregulated in pancreatic ductal adenocarcinomas (PDAC). However, how COX-2 promotes PDAC development is unclear. While previous studies have evaluated the efficacy of COX-2 inhibition via the use of non steroidal anti-inflammatory drugs (NSAIDs) or the COX-2 inhibitor celecoxib in PDAC models, none have addressed the cell intrinsic vs. microenvironment roles of COX-2 in modulating PDAC initiation and progression. We tested the cell intrinsic role of COX-2 in PDAC progression, using both loss-of-function and gain-of-function approaches. Cox-2 deletion in Pdx1+ pancreatic progenitor cells significantly delays the development of PDAC in mice with K-ras activation and Pten haploinsufficiency. Conversely, COX-2 over-expression promotes early onset and progression of PDAC in the K-ras mouse model. Loss of PTEN function is a critical factor in determining lethal PDAC onset and overall survival. Mechanistically, COX-2 over-expression increases P-AKT levels in the precursor lesions of Pdx1+;K-rasG12D/+;Ptenlox/+ mice in the absence of Pten LOH. In contrast, Cox-2 deletion in the same setting diminishes P-AKT levels and delays cancer progression. These data suggest an important cell intrinsic role for COX-2 in tumor initiation and progression through activation of the PI3K/AKT pathway. PDAC that is independent of intrinsic COX-2 expression eventually develops with decreased FKBP5 and increased GRP78 expression, two alternate pathways leading to AKT activation. Together, these results support a cell intrinsic role for COX-2 in PDAC development and suggest that, while anti-COX-2 therapy may delay the development and progression of PDAC, mechanisms known to increase chemoresistance through AKT activation must also be overcome.
Cell intrinsic role of COX-2 in pancreatic cancer development.
Specimen part
View SamplesPancreatic ductal adenocarcinoma (PDAC) has a characteristically dense stroma comprised predominantly of cancer associated fibroblasts (CAFs). CAFs promote tumor growth, metastasis and treatment resistance. We aimed to investigate the molecular changes and functional consequences associated with chemotherapy treatment of PDAC CAFs.
Chemotherapy-Induced Inflammatory Gene Signature and Protumorigenic Phenotype in Pancreatic CAFs via Stress-Associated MAPK.
Specimen part
View SamplesGene expression profile in circulating leukocytes identifies patients with coronary artery disease
Gene expression patterns in peripheral blood correlate with the extent of coronary artery disease.
Sex, Age, Specimen part, Race
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