Sporadic Creutzfeldt-Jakob disease (sCJD) is the most prevalent form of human prion disease and it is characterized by the presence of neuronal loss, spongiform degeneration, chronic inflammation and the accumulation of misfolded and pathogenic prion protein (PrPSc). The molecular mechanisms underlying these alterations are largely unknown, but the presence of intracellular neuronal calcium (Ca+2) overload, a general feature in models of prion diseases, is suggested to play a key role in prion pathogenesis. Here we describe the presence of massive regulation of Ca+2 responsive genes in sCJD brain tissue, accompanied by two Ca+2-dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain activation in sCJD is linked to the cleavage of their cellular substrates, impaired autophagy and lysosomal damage, which is partially reversed by Calpain inhibition in a cellular prion model. Calpain 1 treatment enhances seeding activity of PrPSc in a prion conversion assay. Neuronal lysosomal impairment caused by Calpain over activation leads to the release of the lysosomal protease Cathepsin S that in sCJD mainly localises in axons. Additionally, massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca+2 homeostasis and activation of Calpain-Cathepsin axis already occur at pre-clinical stages of the disease as detected in a humanized sCJD mouse model. Altogether our work indicates that unbalanced Calpain-Cathepsin activation is a relevant contributor to the pathogenesis of sCJD at multiple molecular levels and a potential target for therapeutic intervention. Overall design: To identify differentially expressed genes during development of sCJD pathology we analysed the expression levels in the cortical region of tg340-PRNP129MM mice infected with sCJD MM1 brain homogenates at pre-clinical (120 dpi) and clinical (180 dpi) stages.
Altered Ca<sup>2+</sup> homeostasis induces Calpain-Cathepsin axis activation in sporadic Creutzfeldt-Jakob disease.
Subject, Time
View SamplesTo identify molecular effects of chronic drug treatment, heroin and methamphetamine treated animals were compared with saline treated animals at multiple time-points using microarray technology. Gene expression profile was assessed 14 h after the last dose of 1, 3, 6 or 12 days drug treatment and after 13, 15, 18 or 24 days of withdrawal.
Common transcriptional effects in the mouse striatum following chronic treatment with heroin and methamphetamine.
Specimen part, Compound
View SamplesChronic exposure to opioids induces adaptations in brain function that lead to the formation of the behavioral and physiological symptoms of drug dependence and addiction.
Behavioral and transcriptional patterns of protracted opioid self-administration in mice.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Invasive lobular carcinoma cell lines are characterized by unique estrogen-mediated gene expression patterns and altered tamoxifen response.
Specimen part, Cell line, Treatment, Time
View SamplesInvasive lobular carcinoma (ILC) is a histological subtype of breast cancer that is frequently associated with favorable outcomes, as ~90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that ILC patients receiving adjuvant endocrine therapy may not benefit from improved outcomes versus other breast cancer patients. Based on these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome in vitro via gene expression microarray analyses and ER ChIP-Seq. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. Response to endocrine therapy was also examined in ILC cell lines. We identified 915 genes that were uniquely E2-regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also regulated in vivo in HCI-013. We observed that MM134 were de novo tamoxifen resistant, and were induced to grow by 4-hydroxytamoxifen, as well as other anti-estrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required FGFR1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance.
Invasive lobular carcinoma cell lines are characterized by unique estrogen-mediated gene expression patterns and altered tamoxifen response.
Specimen part, Cell line, Treatment, Time
View SamplesInvasive lobular carcinoma (ILC) is a histological subtype of breast cancer that is frequently associated with favorable outcomes, as ~90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that ILC patients receiving adjuvant endocrine therapy may not benefit from improved outcomes versus other breast cancer patients. Based on these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome in vitro via gene expression microarray analyses and ER ChIP-Seq. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. Response to endocrine therapy was also examined in ILC cell lines. We identified 915 genes that were uniquely E2-regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also regulated in vivo in HCI-013. We observed that MM134 were de novo tamoxifen resistant, and were induced to grow by 4-hydroxytamoxifen, as well as other anti-estrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required FGFR1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance.
Invasive lobular carcinoma cell lines are characterized by unique estrogen-mediated gene expression patterns and altered tamoxifen response.
Specimen part, Cell line, Treatment, Time
View SamplesForty-four paired (from the same patient) samples of head and neck squamous cell carcinoma (HNSCC) and normal tissue were studied with Affymetrix U95A chips. A stringent multi-test approach, combining 7 traditional and microarray-specific statistical tests, was used to analyze the resultant data. Candidate genes were assigned to tiers of significance based on the number of statistical tests that each gene satisfied. Representative genes (both up-regulated and down-regulated) from each of the 3 tiers would be quantified with RT-PCR on both microarray-tested and new samples of HNSCC.
Selection and validation of differentially expressed genes in head and neck cancer.
No sample metadata fields
View SamplesLymphocytes represent basic components of vertebrate adaptive immune systems, suggesting the utility of non-mammalian models to define the molecular basis of their development and differentiation. Our forward genetic screens in zebrafish for recessive mutations affecting early T cell development revealed several major genetic pathways. The identification of lineage-specific transcription factors and specific components of cytokine signaling and DNA replication/repair pathways known from studies of immuno-compromised mammals provided an evolutionary cross-validation of the screen design. Unexpectedly, however, certain pre-mRNA processing factor genes, including tnpo3, encoding a regulator of alternative splicing, were also found to play a specific role in early T cell development. In both zebrafish and mouse, TNPO3 deficiency impairs intrathymic T cell differentiation, illustrating evolutionarily conserved and cell type-specific functions of certain pre-mRNA processing factor. Overall design: Taking advantage of the apparent evolutionary conservation of lymphocyte-based immunity, we conducted genetic screens in zebrafish aimed at identifying novel regulators of T lymphocyte development. Apart from mutations in genes encoding lymphoid lineage-specific transcription factors, and components of cytokine signaling and DNA replication/repair pathways, mutations in genes encoding pre-mRNA processing factors were also found. To examine the molecular consequences, transcriptome analyses were conducted for three mutants, snapc3, lsm8, tnpo3.
Forward Genetic Screens in Zebrafish Identify Pre-mRNA-Processing Pathways Regulating Early T Cell Development.
No sample metadata fields
View SamplesSequencing of olaparib-resistant PEO1 derivatives (C4, C5, C10 and C18) and parental PEO1 (P1 and P2) cells was performed in order to determine mechanisms of acquired resistance in the resistant cell lines. PEO1 parental cell lines were authenticated prior to sequencing. PEO1 parental were confirmed to be BRCA2-mutated (5139C>G). Olaparib PEO1 resistant cells were generated through a step-wise escalation of olaparib (10nM to 8uM olaparib). In olaparib resistant lines an increase canonical Wnt signaling and loss of of non-canonical Wnt signaling was observed. Overall design: Sequencing of olaparib-resistant PEO1 derivatives (C4, C5, C10, and C18) and parental PEO1 cells was performed in order to determine mecahnisms of acquired resistance.
Activation of Wnt signaling promotes olaparib resistant ovarian cancer.
Cell line, Subject
View SamplesInbred Long-Sleep (ILS) and Inbred Short-Sleep (ISS) mice exhibit a large difference in a number of alcohol and drug related behaviors. This study examined the expression levels of transcripts in these strains in the cerebellum, which is a major target of ethanols actions in the CNS, in order to find differentially expressed candidate genes for these phenotypes. Cerebellum was specifically chosen due to the fact that Purkinje cell sensitivity to ethanol in these strains is highly correlated to "sleep time", the measure of ethanol sensitivity used with these strains. Naive mice were used because differences in sensitivity are observed upon initial exposure to ethanol.
Expression profiling identifies novel candidate genes for ethanol sensitivity QTLs.
Sex, Specimen part
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