Abstract. The role of platelets in hemostasis and thrombosis is clearly established; however, the mechanisms by which platelets mediate inflammatory and immune pathways are less well understood. Platelets interact and modulate the function of blood and vascular cells by releasing bioactive molecules. Although the platelet is anucleate, it contains transcripts that may mirror disease. Platelet mRNA is only associated with low-level protein translation, however, platelets have a unique membrane structure allowing for the passage of small molecules, leading to the possibility that its cytoplasmic RNA may be passed to nucleated cells. To examine this question, platelet-like particles with labeled RNA were co-cultured with vascular cells. Co-culture of platelet-like particles with activated THP-1, monocytic, and endothelial cells led to visual and functional RNA transfer. Post-transfer microarray gene expression analysis of THP-1 cells showed an increase in HBG1/HBG2 and HBA1/HBA2 expression which was directly related to the transfer. Infusion of wild-type platelets into a TLR2 deficient mouse model established in vivo confirmation of select platelet RNA transfer to leukocytes. By specifically transferring green fluorescent protein, it was also observed that external RNA was functional in the recipient cells. The observation that platelets possess the capacity to transfer cytosolic RNA suggests a new function for platelets in the regulation of vascular homeostasis.
Platelets and platelet-like particles mediate intercellular RNA transfer.
Specimen part, Cell line
View SamplesThe purpose of this study was to search for microgravity-sensitive genes, specifically for apoptotic genes influenced by the microgravity environment and other genes related to immune response.
Gene expression alterations in activated human T-cells induced by modeled microgravity.
No sample metadata fields
View SamplesThe below table includes a smaller list of data that was analyzed by dChip and filtered by pvalue such that a file with about 4600 genes was obtained, which allowed for ease of use from 40,000 genes.
Identification of mechanosensitive genes in osteoblasts by comparative microarray studies using the rotating wall vessel and the random positioning machine.
Specimen part
View SamplesNrf2 is an important therapeutic target as activation of this pathway detoxifies harmful insults and reduces oxidative stress. However, the role of Nrf2 in cancer biology is controversial. Protection against oxidative stress and inflammation can confer a survival advantage to tumor cells, leading to a poor prognosis, and constitutive activation of Nrf2 has been detected in numerous tumors. In our study, we examined the role of two clinically relevant classes of Nrf2 activators, the synthetic triterpenoids (CDDO-Im and CDDO-Me) and dimethyl fumarate (DMF) in lung cancer.
Dimethyl fumarate and the oleanane triterpenoids, CDDO-imidazolide and CDDO-methyl ester, both activate the Nrf2 pathway but have opposite effects in the A/J model of lung carcinogenesis.
Sex, Specimen part
View SamplesThe miR-16 family, which targets genes important for the G1-S transition, is a known modulator of the cell cycle, and members of this family are often deleted or down-regulated in many types of cancers. Here we report the reciprocal relationship - that of the cell cycle controlling the miR-16 family. Levels of this family increase rapidly as cells are arrested in G0. Conversely, as cells are released from G0 arrest, levels of the miR-16 family rapidly decrease. Such rapid changes are made possible by the unusual instabilities of several family members. The repression mediated by the miR-16 family is sensitive to these cell cycle changes, which suggests that the rapid up-regulation of the miR-16 family reinforces cell cycle arrest in G0. Upon cell cycle re-entry, the rapid decay of several members allows levels of the family to decrease, alleviating repression of target genes and allowing proper resumption of the cell cycle. Overall design: Small RNAs were profiled by high-throughput sequencing either during synchronous release after serum starvation or during cell-cycle arrest by contact inhibition.
MicroRNA destabilization enables dynamic regulation of the miR-16 family in response to cell-cycle changes.
Specimen part, Cell line, Subject
View SamplesTranslation and mRNA decay are intimately connected processes, and translational inhibition often precedes and stimulates transcript degradation. Here, we have focused on methods that allow determination of mRNA stability on a transcriptome-wide scale. We describe experimental and computational methods for the two most commonly used approaches (transcriptional inhibition and metabolic labeling), and we discuss associated caveats. Overall design: Metabolic labeling time courses (1, 2, 4, 8, 12, 24 hr) using 4SU were performed in HEK293.
Determining mRNA half-lives on a transcriptome-wide scale.
Treatment, Subject
View SamplesOlfactory sensory neurons express just one out of a possible ~1000 odorant receptor genes, reflecting an exquisite mode of gene regulation. In one model, once an odorant receptor is chosen for expression, other receptor genes are suppressed by a negative feedback mechanism, ensuring a stable functional identity of the sensory neuron for the lifetime of the cell. The signal transduction mechanism subserving odorant receptor gene silencing remains obscure, however. Here we demonstrate in the zebrafish that odorant receptor gene silencing is dependent on receptor activity. Moreover, we show that signaling through G protein ß? subunits is both necessary and sufficient to suppress the expression of odorant receptor genes, and likely acts through histone methylation to maintain the silenced odorant receptor genes in transcriptionally inactive heterochromatin. These results provide new insights linking receptor activity with the epigenetic mechanisms responsible for ensuring the expression of one odorant receptor per olfactory sensory neuron. Overall design: Total 6 samples were analyzed-3 controls & 3 samples
Normalization of RNA-seq data using factor analysis of control genes or samples.
No sample metadata fields
View SamplesMidbrain dopamine neurons project to numerous targets throughout the brain to modulate various behaviors and brain states. Within this small population of neurons exists significant heterogeneity based on physiology, circuitry, and disease susceptibility. Recent studies have shown that dopamine neurons can be subdivided based on gene expression; however, the extent to which genetic markers represent functionally relevant dopaminergic subpopulations has not been fully explored. Here we performed single-cell RNA-sequencing of mouse dopamine neurons and validated studies showing that Neurod6 and Grp are selective markers for dopaminergic subpopulations. Using a combination of multiplex fluorescent in situ hybridization, retrograde labeling, and electrophysiology in mice of both sexes, we defined the anatomy, projection targets, physiological properties, and disease vulnerability of dopamine neurons based on Grp and/or Neurod6 expression. We found that the combinatorial expression of Grp and Neurod6 defines dopaminergic subpopulations with unique features. Grp/Neurod6 dopamine neurons reside in the ventromedial VTA, send projections to the medial shell of the nucleus accumbens, and have noncanonical physiological properties. Grp/Neurod6- DA neurons are found in the VTA as well as in the ventromedial portion of the SNc, where they project selectively to the dorsomedial striatum. Grp-/Neurod6 DA neurons represent a smaller VTA subpopulation, which is preferentially spared in a 6-OHDA model of Parkinson's disease. Together, our work provides detailed characterization of Neurod6 and Grp expression in the midbrain and generates new insights into how these markers define functionally relevant dopaminergic subpopulations with distinct projection patterns, physiology, and disease vulnerability. Overall design: We collected a total of 384 neurons from 8 different p26-p34 DAT-Cre::Ai9 mice (6 male 2 female) to isolate DA neurons. RNA was captured from each samples neurons on separate fluidigm chips then all samples were pooled before sequencing.
Combinatorial Expression of <i>Grp</i> and <i>Neurod6</i> Defines Dopamine Neuron Populations with Distinct Projection Patterns and Disease Vulnerability.
Sex, Specimen part, Cell line, Subject
View SamplesPeripheral whole blood-based gene expression profiling has become one of the most common strategies exploited in the development of clinically relevant biomarkers. However, the ability to identify biologically meaningful conclusions from gene expression patterns in whole blood is highly problematic. First, it is difficult to know whether or not expression patterns in whole blood capture those in primary tissues. Second, if explicit steps are not taken to accommodate the extremely elevated expression levels of globin in blood then large-scale multi-probe microarray-based studies can be severely compromised. Many studies consider the use of mouse blood as a model for human blood in addition to considering blood gene expression levels as a general surrogate for gene expression levels in other tissues. We explored the effects of globin reduction on peripheral mouse blood in the detection of genes known to be expressed in human tissues. Globin reduction resulted in 1.) a significant increase in the number of probes detected (5840 944 vs 12411 1904); 2.) increased expression for 4128 probe sets compared to non-globin reduced blood (p < .001, two-fold); 3.) improved detection of genes associated with many biological pathways and diseases; and 4.) an increased ability to detect genes expressed in 27 human tissues (p < 10-4). This study suggests that although microarray-based mouse blood gene expression studies that do not consider the effects of globin are severely compromised, globin-reduced mouse whole blood gene expression studies can be used to capture the expression profiles of genes known to contribute to various human diseases.
The effects of globin on microarray-based gene expression analysis of mouse blood.
Sex, Age, Specimen part
View SamplesWe investigated the morphological roots decisions of Arabidopsis in a NO3- heterogeneous medium. To do so, we used the Split-Root System which is an experimental set up to assess root decisions in nutrient heterogeneous medium. Split-root plants have been subjected to three different treatments. Control KNO3 plants received KNO3 on both sides of the root system (C.NO3) and Control KCl plants received KCl on both sides (C.KCl) as a nitrogen deprivation treatment. 'Split' plants received KNO3 on one side (Sp.NO3) and KCl on the other side (Sp.KCl) of the root system to assess the root decision-making in a heterogeneous environment.
Nitrogen economics of root foraging: transitive closure of the nitrate-cytokinin relay and distinct systemic signaling for N supply vs. demand.
Specimen part, Treatment
View Samples