The sense of hearing depends on the faithful transmission of sound information from the ear to the brain by spiral ganglion (SG) neurons. However, how SG neurons develop the connections and properties that underlie auditory processing is largely unknown.
Developmental profiling of spiral ganglion neurons reveals insights into auditory circuit assembly.
Specimen part
View SamplesOBJECTIVE: To analyze genome-wide changes in chondrocyte gene expression in a surgically induced model of early osteoarthritis (OA) in rats, to assess the similarity of this model to human OA, and to identify genes and mechanisms leading to OA pathogenesis. METHODS: OA was surgically induced in 5 rats by anterior cruciate ligament transection and partial medial meniscectomy. Sham surgery was performed in 5 additional animals, which were used as controls. Both groups underwent 4 weeks of forced mobilization, 3 times per week. RNA was extracted directly from articular chondrocytes in the OA (operated), contralateral, and sham-operated knees. Affymetrix GeneChip expression arrays were used to assess genome-wide changes in gene expression. Expression patterns of selected dysregulated genes, including Col2a1, Mmp13, Adamts5, Ctsc, Ptges, and Cxcr4, were validated by real-time polymerase chain reaction, immunofluorescence, or immunohistochemistry 2, 4, and 8 weeks after surgery. RESULTS: After normalization, comparison of OA and sham-operated samples showed 1,619 differentially expressed probe sets with changes in their levels of expression >/=1.5-fold, 722 with changes >/=2-fold, 135 with changes >/=4-fold, and 20 with changes of 8-fold. Dysregulated genes known to be involved in human OA included Mmp13, Adamts5, and Ptgs2, among others. Several dysregulated genes (e.g., Reln, Phex, and Ltbp2) had been identified in our earlier microarray study of hypertrophic chondrocyte differentiation. Other genes involved in cytokine and chemokine signaling, including Cxcr4 and Ccl2, were identified. Changes in gene expression were also observed in the contralateral knee, validating the sham operation as the appropriate control. CONCLUSION: Our results demonstrate that the animal model mimics gene expression changes seen in human OA, supporting the relevance of newly identified genes and pathways to early human OA. We propose new avenues for OA pathogenesis research and potential targets for novel OA treatments, including cathepsins and cytokine, chemokine, and growth factor signaling pathways, in addition to factors controlling the progression of chondrocyte differentiation.
Global analyses of gene expression in early experimental osteoarthritis.
No sample metadata fields
View SamplesPrimary micromass cultures derived from 11.5 day old mouse embryo limb buds were cultured for 15 days in differentiating conditions (beta-glycerophosphate and ascorbic acid). Total RNA from differentiating chondrocytes was isolated every three days i.e. days 3,6,9,12 and 15 and hybridized to MOE430A chips. Objective: Gain a view of the temporal gene expression changes occuring during chondrocyte differentiation.
Microarray analyses of gene expression during chondrocyte differentiation identifies novel regulators of hypertrophy.
No sample metadata fields
View SamplesAnalysis of livers of male and female B6C3F1 mice exposed to prototype treatments from five classes of model hepatotoxicants. These hepatotoxicants include compounds that activate the peroxisome proliferator-activated receptor (PPAR), induce the inflammatory response, activate the constitutive androstane receptor (CAR), stimulate the hypoxia signal transduction pathway, and activate the aryl-hydrocarbon receptor (AHR). The results provide insights into the shared and unique pathways that are activated across these model hepatotoxicants.
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Age, Compound, Time
View SamplesPPAR-null and wild-type male mice treated with PFHxS or PFNA
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Specimen part, Compound
View SamplesMany environmentally-relevant chemicals and drugs activate the nuclear receptor pregnane X receptor (PXR). Activation of PXR can lead to increases in liver weight in part through hepatocyte replication similar to a large number of compounds that activate other nuclear receptors such as the peroxisome proliferator-activated receptor alpha and the constitutive activated receptor (CAR). PXR controls the expression of a large battery of genes involved in xenobiotic metabolism. Identification of genes that are accurate predictors of PXR activation would be useful in high-throughput screens to assess potential toxicity and drug-drug interactions. Here, we identified PXR-dependent genes in the mouse liver after exposure to pregnenolone 16alpha-carbinonitrile (PCN), a chemical that is often used as a model PXR agonist.
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Specimen part, Compound
View SamplesGrowth hormone signaling in hepatocytes is fundamentally important. Disruptions in this pathway have led to fatty liver and other metabolic abnormalities. Growth hormone signals through the JAK2/STAT5 pathway. Mice with hepatocyte specific deletion of STAT5 were previously shown to develop fatty liver. Our aim in this study was to determine the effect of deleting JAK2 in hepatocytes on liver gene expression. To do so, we generated animals with hepatocyte specific deletion of JAK2.
Abrogation of growth hormone secretion rescues fatty liver in mice with hepatocyte-specific deletion of JAK2.
Sex, Age, Specimen part
View SamplesPancreatic Ductal Adenocarcinoma (PDAC) is one of the most aggressive human malignancies. In our studies, we find that the Gli transcription factors are required for Kras initiation of pancreatic tumorigenesis. In order to identify the downstream transcriptional targets of Gli in PDAC, we conducted gene expression analysis using Gli3T, a transcriptional repressor of Gli.
The activity of Gli transcription factors is essential for Kras-induced pancreatic tumorigenesis.
Cell line
View SamplesActivation of the canonical Wnt signaling pathway is commonly observed in pancreatic cancer. We therefore sought to identify a gene expression profile associated with the activation of this pathway in pancreatic cancer cells.
Activation of WNT/β-Catenin Signaling Enhances Pancreatic Cancer Development and the Malignant Potential Via Up-regulation of Cyr61.
Specimen part, Cell line
View SamplesMice of indicated ages and genotypes were perfused and their brains dissected and dissociated. Cells were fixed, immunolabeled and FACS sorted. RNA was extracted from neuron, astrocyte, and microglial cell populations. Typical RIN=4-5 for neurons, 6-8 for astrocytes, and 5-7 for microglia. Typical RNA yields ~100ng for neurons, ~20ng for microglia, and ~10ng for astrocytes. cDNA was generated from up to 25 ng of total RNA using Nugen’s RNA-Seq method for low-input RNA samples, Ovation RNA-Seq System V2 (NuGEN). (Per manufacturers instructions, total RNA was neither depleted of rRNA nor polyA-selected.) 1 µg of sheared cDNA was taken into further processing, starting at end repair step, using Illumina’s TruSeq RNA Sample Preparation Kit v2 (Illumina). The "SAMPLE_ID" sample characteristic is a sample identifier internal to Genentech. The ID of this project in Genentech''s ExpressionPlot database is PRJ0006149 Overall design: Astrocytes, microglia and neurons were sorted from 7- or 13-month old PS2APP or non-transgenic mice, 4 = n = 7 per group.
Untangling the brain's neuroinflammatory and neurodegenerative transcriptional responses.
Age, Specimen part, Subject
View Samples