PIWI interacting RNAs (piRNAs) provide defense against transposable element (TE) expansion in the germline of metazoans. piRNAs are processed from the transcripts encoded by specialized heterochromatic clusters enriched in damaged copies of transposons. How these regions are recognized as a source of piRNAs is still elusive. The aim of this study is to determine how transgenes that contain a fragment of the LINE-like I transposon lead to an acquired TE resistance in Drosophila. We show that such transgenes, being inserted in unique euchromatic regions which normally do not produce small RNAs, become de novo bidirectional piRNA clusters that silence I-element activity in the germline. Strikingly, small RNAs of both polarities are generated from the entire transgene and flanking genomic sequences — not only from the transposon fragment. Chromatin immunoprecipitation analysis shows that in ovaries the trimethylated histone 3 lysine 9 (H3K9me3) mark associates with transgenes producing piRNAs. We show that transgene-derived hsp70 piRNAs stimulate in trans cleavage of cognate endogenous transcripts with subsequent processing of the non-homologous parts of these transcripts into piRNAs. Overall design: The fractions of small RNAs (19-29 nt) from ovaries of wild type and 11 transgenic lines of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.
De novo piRNA cluster formation in the Drosophila germ line triggered by transgenes containing a transcribed transposon fragment.
Specimen part, Subject
View SamplesGermline-specific RNA helicase Spindle-E (Spn-E) is known to be essential for piRNA silencing in Drosophila that takes place mainly in the perinuclear nuage granules. Loss-of-function spn-E mutations lead to tandem Stellate genes derepression in the testes and retrotransposon mobilization in the ovaries. However, Spn-E functions in the piRNA pathway are still obscure. Analysis of total library of short RNAs from the testes of spn-E heterozygous flies revealed the presence of abundant piRNA ping-pong pairs originating from Su(Ste) transcripts. The abundance of these ping-pong pairs were sharply reduced in the library from the testes of spn-E mutants. Thus we found that ping-pong mechanism contributed to Su(Ste) piRNA generation in the testes. The lack of Spn-E caused a significant drop of protein levels of key ping-pong participants, Aubergine (Aub) and AGO3 proteins of PIWI subfamily, in the germline of both males and females, but did not disrupt of their assembly in nuage granules. We found that observed decline of the protein expression was not caused by suppression of aub and ago3 transcription as well as total transcription, indicating possible contribution of Spn-E to post-transcriptional regulation. Overall design: The fractions of small RNAs (19-29 nt) from testis of Drosophila melanogaster spnE/+ spnE/- strains were sequenced using Illumina HiSeq 2000.
RNA helicase Spn-E is required to maintain Aub and AGO3 protein levels for piRNA silencing in the germline of Drosophila.
Specimen part, Subject
View SamplesTo attain deeper insight into metabolic alterations in Trpm6 gene deficient mice we used microarrays for profiling of hepatic transcripts of Trpm6 ko and control mice.
Epithelial magnesium transport by TRPM6 is essential for prenatal development and adult survival.
Sex, Age
View SamplesAlzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level we provide evidence that anle138b blocks the formation of conducting Aß pores without changing the membrane embedded Aß-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further. Overall design: APPdelta9 and Wildtype mouse treated with anle138b or placebo
The diphenylpyrazole compound anle138b blocks Aβ channels and rescues disease phenotypes in a mouse model for amyloid pathology.
Age, Cell line, Subject
View SamplesHuntingtons disease (HD) is an incurable hereditary neurodegenerative disorder, which manifests itself as a loss of GABAergic medium spiny (GABA MS) neurons in the striatum and caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. There is no cure for HD, existing pharmaceutical can only relieve its symptoms. Here, induced pluripotent stem cells were established from patients with low CAG repeat expansion in the huntingtin gene, and were then efficiently differentiated into GABA MS-like neurons under defined culture conditions. Analysis of differentially expressed genes between Huntingtons disease and wild type iPSCs derived GABA MS-like neurons has been performed.
Manifestation of Huntington's disease pathology in human induced pluripotent stem cell-derived neurons.
Age, Specimen part
View SamplesSystemic administration of -adrenoceptor (-AR) agonists has been found to induce skeletal muscle hypertrophy and significant metabolic changes. In the context of energy homeostasis, the importance of -AR signaling has been highlighted by the inability of 13-AR-deficient mice to regulate energy expenditure and susceptibility to diet induced obesity. However, the molecular pathways and gene expression changes that initiate and maintain these phenotypic modulations are poorly understood. Therefore, the aim of this study was to identify differential changes in gene expression in murine skeletal muscle associated with systemic acute administration of the 2-AR agonist formoterol. Skeletal muscle gene expression (from murine tibialis anterior) was profiled at both 1 and 4 hours following systemic administration of the 2-AR agonist formoterol, using 46K Illumina(R) Sentrix BeadArrays. Illumina expression profiling revealed significant expression changes in genes associated with skeletal muscle hypertrophy, myoblast differentiation, metabolism, circadian rhythm, transcription, histones, and oxidative stress.
Expression profiling of skeletal muscle following acute and chronic beta2-adrenergic stimulation: implications for hypertrophy, metabolism and circadian rhythm.
Treatment
View SamplesCanonical Wnt signaling controls proliferation and differentiation of osteogenic progenitor cells, and tumor-derived secretion of the Wnt antagonist Dickkopf-1 (Dkk1) is correlated with osteolyses and metastasis in many bone malignancies. However, the role of Dkk1 in the oncogenesis of primary osteosarcoma (OS) remains unexplored. Here, we over-expressed Dkk1 in the OS cell line MOS-J. Contrary to expectations, Dkk1 had autocrine effects on MOSJ cells in that it increased proliferation and resistance to metabolic stress in vitro. In vivo, Dkk1 expressing MOS-J cells formed larger and more destructive tumors than controls. These effects were attributed in part to up-regulation of the stress response enzyme and cancer stem cell marker aldehyde-dehydrogenase-1 (ALDH1) through Jun-N-terminal kinase signaling. This is the first report linking Dkk1 to tumor stress resistance, further supporting the targeting of Dkk1 not only to prevent and treat osteolytic bone lesions but also to reduce numbers of stress-resistant tumor cells.
An unexpected role for a Wnt-inhibitor: Dickkopf-1 triggers a novel cancer survival mechanism through modulation of aldehyde-dehydrogenase-1 activity.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Comparative Transcriptome Profiling Reveals Coding and Noncoding RNA Differences in NSCLC from African Americans and European Americans.
Sex, Age, Specimen part, Disease, Race, Subject
View SamplesMdr1a-, Bcrp-, and Mrp2-knockout rats are a more practical species for ADME studies than murine models and previously demonstrated expected alterations in pharmacokinetics of various probe substrates. At present, gene expression and pathology changes were systematically studied in small intestine, liver, kidney, and brain tissue from male SAGE Mdr1a-, Bcrp-, and Mrp2-knockout rats versus wild-type Sprague Dawley controls. Gene expression data supported the relevant knockout genotype. As expected, Mrp2-knockout rats were hyperbilirubinemic and exhibited upregulation of hepatic Mrp3. Overall, few alterations were observed within 137 ADME-relevant genes. The two most consequential changes were upregulation of intestinal carboxylesterase in Mdr1a-knockouts and catechol-O-methyltransferase in all tissues of Bcrp-knockout rats. Previously reported upregulation of hepatic Mdr1b P-glycoprotein in proprietary Wistar Mdr1a-knockout rats was not observed in the SAGE counterpart investigated herein. Relative liver and kidney weights were 22-53% higher in all three knockouts, with microscopic increases in hepatocyte size in Mdr1a- and Mrp2-knockout rats, and glomerular size in Bcrp- and Mrp2-knockouts. Increased relative weight of clearing organs is quantitatively consistent with reported increases in clearance of drugs that are not substrates of the knocked-out transporter. Overall, SAGE knockout rats demonstrated modest compensatory changes, which do not preclude their general application to study transporter-mediated pharmacokinetics. However until future studies elucidate the magnitude of functional change, caution is warranted in rare instances of extensive metabolism by catechol-O-methyltransferase in Bcrp-knockouts and intestinal carboxylesterase in Mdr1a-knockout rats, specifically for molecules with free catechol groups and esters subject to gut wall hydrolysis.
Minor compensatory changes in SAGE Mdr1a (P-gp), Bcrp, and Mrp2 knockout rats do not detract from their utility in the study of transporter-mediated pharmacokinetics.
Sex, Specimen part
View SamplesTranslational Relevance
Comparative Transcriptome Profiling Reveals Coding and Noncoding RNA Differences in NSCLC from African Americans and European Americans.
Sex, Age, Race, Subject
View Samples