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 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 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 SamplesAlthough multiple gene and protein expression have been extensively profiled in human pulmonary arterial hypertension (PAH), the mechanism for the development and progression of pulmonary hypertension remains elusive. Analysis of the global metabolomic heterogeneity within the pulmonary vascular system leads to a better understanding of disease progression. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted glycolysis, increased TCA cycle, and fatty acid metabolites with altered oxidation pathways in the severe human PAH lung. The results suggest that PAH has specific metabolic pathways contributing to increased ATP synthesis for the vascular remodeling process in severe pulmonary hypertension. These identified metabolites may serve as potential biomarkers for the diagnosis of severe PAH. By profiling metabolomic alterations of the PAH lung, we reveal new pathogenic mechanisms of PAH in its later stage, which may differ from the earlier stage of PAH, opening an avenue of exploration for therapeutics that target metabolic pathway alterations in the progression of PAH.
De novo synthesize of bile acids in pulmonary arterial hypertension lung.
Specimen part
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 SamplesGonadotrope or null cell pituitary tumors present clinically with signs of hypogonadism and hypopituitarism, together with visual disturbances due to mass effects. Since there are no medical therapies, surgery and/or radiation are the only therapeutic options. To identify dysregulated genes and/or pathways that may play a role in tumorigenesis and/ or progression, molecular profiling was performed on 14 gonadotrope tumors and 9 normal human pituitaries from autopsy samples. Principle component analysis (PCA) revealed clear discrimination between tumor and normal pituitary gene expression profiles. Bioinformatic analysis identified specific genes and pathways that were highly differentially regulated, including a cohort of putative downstream effectors of p53 were repressed in gonadotrope pituitary tumors, including GADD45, GADD45 and Reprimo with concomitant downregulation of the upstream regulator, PLAGL1. PLAGL1 reexpression in gonadotrope cells did not directly modulate the downstream targets. Further functional analysis of GADD45 was performed. Overexpression of GADD45 in mouse gonadotrope cells blocked proliferation, increased rates of apoptosis in response to growth factor withdrawal and increased colony formation in soft agar. In contrast to prior studies with GADD45, methylation interference assays showed no evidence of epigenetic modification of the GADD45 promoter in pituitary tumors. Thus, our data suggest that many components downstream of p53 are suppressed in gonadotrope pituitary tumors. A novel candidate, GADD45 is low in tumors and reexpression blocks proliferation, survival and tumorigenesis in gonadotrope cells. Unlike GADD45, GADD45 is not methylated to block its expression. Together these studies identify new targets and mechanisms to explore concerning pituitary tumor initiation and progression.
Identification of growth arrest and DNA-damage-inducible gene beta (GADD45beta) as a novel tumor suppressor in pituitary gonadotrope tumors.
Sex
View SamplesERRa is an orphan nuclear receptor with an established role in cell metabolism. Our studies demonstrate that acute or chronic loss of ERRa broadly affects mitochondrial and glycolytic metabolism in CD4+ T cells and results in diminished T cell function and differentation.
Estrogen-related receptor-α is a metabolic regulator of effector T-cell activation and differentiation.
Specimen part, Treatment
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