Study on selective vulnerability of certain brain regions to oxidative stress. Here we selected 4 brain regions (hippocampal CA1 and CA3, cerebral cortex, and cerebellar granular layer) to study this phenomenon.
Genomic and biochemical approaches in the discovery of mechanisms for selective neuronal vulnerability to oxidative stress.
Specimen part
View SamplesGenome-wide gene expression was obtained in three auditory brainstem nuclei (defined below), at two different ages in mice, postnatal day (P)3 and P14. The primary aim was to identify genes which are differentially expressed between the medial nucleus of the trapezoid body (MNTB) and the superior olive (LSO), at both age groups.
BMP signaling specifies the development of a large and fast CNS synapse.
Sex, Specimen part
View SamplesBACKGROUND: miRNA have been shown to play an important role during immune-mediated diseases such as inflammatory bowel disease. The aim of this study was to assess differential expression of miRNA between uninfected and infected mice with Clostridium difficile strain VPI 10463 RESULTS: MicroRNA (miRNA)-sequencing analysis indicated that miR-146b, miR-1940, and miR-1298 were significantly overexpressed in colons of C. difficile-infected mice Overall design: Colon of uninfected and C.difficile-infected C57BL6/J WT mice were sampled at day 4 post-infection with Clostridium difficile VPI 10463. The infection dose was 107 cfu/mouse.
Modeling the role of peroxisome proliferator-activated receptor γ and microRNA-146 in mucosal immune responses to Clostridium difficile.
Specimen part, Cell line, Subject
View SamplesDevelopment, growth and adult survival are coordinated with available metabolic resources. The insulin/IGF and TOR signaling pathways relay nutritional status, thereby ascertaining that the organism responds appropriately to environmental conditions. MicroRNAs are short (21-23 nt) regulatory RNAs that confer specificity on the RNA-induced silencing complex (RISC) to inhibit a given set of mRNA targets. We profiled changes in miRNA expression during adult life in Drosophila melanogaster and determined that miR-277 is down-regulated with age. This miRNA controls branched-chain amino acid (BCAA) catabolism and the activity of the TOR kinase, a central growth regulator. Metabolite analysis suggests that the mechanistic basis may be an accumulation of BCKAs, rather than BCAAs, thus avoiding potentially detrimental consequences of increased branched chain amino acid levels on e.g. translational fidelity. Constitutive miR-277 expression as well as transgenic inhibition with a miRNA sponge construct shortens lifespan. Furthermore, constitutive miR-277 expression is synthetically lethal with reduced insulin signaling. Thus, optimal metabolic adaptation requires tuning of cellular BCAA catabolism by miR-277 to be concordant with systemic growth signaling. Overall design: Transgenic Drosophila melanogaster fruitflies carrying strong, ubiquitously expressed pre-miR277 hairpins (wt and two mutant versions) were dissected, total RNA was extracted from the abdomen and gel-purified for size selection (~18-30 nt). Digested plasmid samples were compared to those of circular plasmids and a nontransfected control. The purpose of this experiment was to demonstrate the extent of expression from mutant pre-miR277 hairpins, mut1 should abolish Drosha-processing while mut2 is conservative.
Drosophila miR-277 controls branched-chain amino acid catabolism and affects lifespan.
Specimen part, Subject
View SamplesPrimary human foreskin fibroblasts (HFF) were exposed to either salt stress (80mM KCl) or heat stress (44ºC). Newly transcribed RNA was labelled by adding 500µM 4-thiouridine (4sU) to the cell culture media for 1h. Total cellular RNA was isolated using Trizol. Newly transcribed RNA was purified following the protocol described in Raedle et al. JoVE 2013. Overall design: Newly transcribed RNA was labelled in one hour intervals during either salt or heat stress (prior to stress, 0-1h or 1-2h). All 4sU-RNA samples were sent for sequencing. Two independent biological replicates were analysed.
HSV-1-induced disruption of transcription termination resembles a cellular stress response but selectively increases chromatin accessibility downstream of genes.
Specimen part, Subject, Time
View SamplesOur studies provide direct evidence that O-glycosylation pathways play a role in the regulation of cell growth through apoptosis and proliferation pathways. Eight small molecular weight analogues of the GalNAc-alpha-1-O-serine/threonine structure based on 1-benzyl-2-acetamido-2- deoxy-alpha-O-D-galactopyranoside have been synthesised and tested in 5 human colorectal cancer cell lines. Three inhibitors, 1-benzyl-2-acetamido-2-deoxy-alpha-O-D-galactopyranoside and the corresponding 2-azido- and C-glycoside analogues, were screened in two colorectal cancer cell lines at 0.5mM and showed induction of apoptosis. Proliferation was down regulated in the same two cell lines with all three inhibitors, as detected by Ki67 staining and gene array. Treatment both cell lines with inhibitors led to changes in glycosylation detected with peanut lectin. The competitive action of the inhibitors resulted in the intracellular formation of 28 aryl-glycan products which were identified by MALDI and electrospray mass spectroscopy. The structures found map onto known O-glycosylation biosynthetic pathways and showed a differential pattern for each of the inhibitors in both cell lines. Gene array analysis of the glycogenes illustrated a pattern of glycosytransferases that matched the glycan structures found in glycoproteins and aryl-glycans formed in the PC/AA/C1/SB10C cells, however there was no action of the three inhibitors on glycogene transcript levels. The inhibitors act at both intermediary metabolic and genomic levels, resulting in altered protein glycosylation and arylglycan formation. These events may play a part in growth arrest.
O-glycan inhibitors generate aryl-glycans, induce apoptosis and lead to growth inhibition in colorectal cancer cell lines.
No sample metadata fields
View SamplesThe genomic landscape of hepatic tissue affected by nonalcoholic steatohepatitis (NASH) in severely obese adolescents undergoing bariatric surgery is unknown. Our purpose here was to uncover genomic profiles of obese controls, and obese cases with nonalcoholic fatty liver disease (NAFLD), borderline nonalcoholic steatohepatitis, and definite nonalcoholic steatohepatitis, in order to clarify molecular functions, biological processes, and pathways that are dysregulated in nonalcoholic steatohepatitis in the severely obese adolescent.
High Prevalence of Nonalcoholic Fatty Liver Disease in Adolescents Undergoing Bariatric Surgery.
Sex, Disease
View SamplesMechanistic study on the differential responses of the two hippocampal adjoining regions, i.e., CA1 and CA3, to elevated oxidative stress.
Genome-wide transcriptome profiling of region-specific vulnerability to oxidative stress in the hippocampus.
No sample metadata fields
View SamplesSmall RNAs have been implicated in numerous cellular processes, including effects on chromatin structure and the repression of transposons. We describe the generation of a small RNA response at DNA ends in Drosophila that is analogous to the recently reported DSB-induced RNAs (diRNAs) or Dicer and Drosha dependent small RNAs (ddRNAs) in Arabidopsis and vertebrates. Active transcription in the vicinity of the break amplifies this small RNA response, demonstrating that the normal mRNA contributes to the endo-siRNA precursor. The double-stranded RNA precursor forms with an antisense transcript that initiates at the DNA break. Breaks are thus sites of transcription initiation, a novel aspect of the cellular DSB response. This response is specific to a double-strand break since nicked DNA structures do not trigger small RNA production. The small RNAs are generated independently of the exact end structure (blunt, 3'- or 5'-overhang), can repress homologous sequences in trans and may therefore - in addition to putative roles in repair - exert a quality control function by clearing potentially truncated messages from genes in the vicinity of the break. Overall design: Drosophila melanogaster S2 cells were cultured and transfected with reporter gene plasmids that were either circular or modified by restriction digest prior to transfection. Following transfection, total RNA was isolated from the cells and gel-purified for size selection (~18-30 nt). Digested plasmid samples were compared to those of circular plasmids and a nontransfected control.
A small RNA response at DNA ends in Drosophila.
Cell line, Treatment, Subject
View SamplesGlud1 (Glutamate dehydrogenase 1) transgenic mice release more excitatory neurotransmitter glutamate to synaptic cleft throughout lifespan.
Gene expression patterns in the hippocampus during the development and aging of Glud1 (Glutamate Dehydrogenase 1) transgenic and wild type mice.
Specimen part
View Samples