Severe malnutrition in young children is associated with signs of hepatic dysfunction such as steatosis and hypoalbuminemia, but its etiology is unknown. To investigate the underlying mechanisms of hepatic dysfunction we used a rat model of malnutrition by placing weanling rats on a low protein or control diet (5% or 20% of calories from protein, respectively) for four weeks. Low protein diet-fed rats developed hypoalbuminemia and severe hepatic steatosis, consistent with the human phenotype. Hepatic peroxisome content was decreased and metabolomic analysis indicated impaired peroxisomal function. Loss of peroxisomes was followed by accumulation of dysfunctional mitochondria and decreased hepatic ATP levels. Fenofibrate supplementation restored hepatic peroxisome abundance and increased mitochondrial fatty acid -oxidation capacity, resulting in reduced steatosis and normalization of ATP and plasma albumin levels. These findings provide important insight into the metabolic
Malnutrition-associated liver steatosis and ATP depletion is caused by peroxisomal and mitochondrial dysfunction.
Sex, Specimen part, Treatment
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Activation of GCN2 kinase by ribosome stalling links translation elongation with translation initiation.
Age
View SamplesRibosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2 (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2 kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress.
Activation of GCN2 kinase by ribosome stalling links translation elongation with translation initiation.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Malignant catarrhal fever of cattle is associated with low abundance of IL-2 transcript and a predominantly latent profile of ovine herpesvirus 2 gene expression.
No sample metadata fields
View SamplesWe hypothesized that the relative abundances of host cell transcripts in lymph nodes of animals with malignant catarrhal fever (MCF), compared to healthy controls, may be used to identify pathways that may help to explain the pathogenesis of MCF. Therefore, an abundance of host cell gene expression patterns in lymph nodes of animals with MCF and healthy controls were analyzed by microarray. Indeed, a vast number of genes related to inflammatory processes, lymphocyte activation, cell proliferation and apoptosis were detected at different abundances. However, the IL-2 transcript was eminent among the transcripts, which were, compared to healthy controls, less abundant in animals with MCF. Compared to healthy cattle, bovines with MCF appear to mimic an IL-2 knockout phenotype that has been described in mice. This supports the hypothesis that immunopathogenic events are linked to the pathogenesis of MCF. IL-2-deficiency may play an important role in the process.
Malignant catarrhal fever of cattle is associated with low abundance of IL-2 transcript and a predominantly latent profile of ovine herpesvirus 2 gene expression.
No sample metadata fields
View SamplesMHCaCre induced knockout of Fog2flox.
Fog2 is critical for cardiac function and maintenance of coronary vasculature in the adult mouse heart.
Sex, Specimen part, Treatment
View SamplesPreterm birth is an important unsolved clinical problem. Despite advanced treatments, infants who survive prematurity remain at increased risk for permanent disabilities. In approximately one-third of cases, prematurity is related to infection and/or inflammation, which renders hostile the normally receptive intrauterine environment. Proinflammatory cytokines provoke up-regulation of genes that promote uterine contractions. Using monolayer cultures of human decidual cells as a model, we profiled the global pattern of gene expression in response to cytokine challenge.
Inflammatory gene networks in term human decidual cells define a potential signature for cytokine-mediated parturition.
Specimen part, Time
View SamplesPremature birth continues to be a challenging pregnancy complication, and a body of literature indicates that inflammation can contribute to premature delivery by converting a receptive uterine environment to a hostile one. Cytokines have been demonstrated to provoke up-regulation of inflammatory genes (e.g. interleukin-1, 6, and 8, tumor necrosis factor-alpha, cyclooxygenase-2, and microsomal prostaglandin E synthase-1).
Inflammatory gene regulatory networks in amnion cells following cytokine stimulation: translational systems approach to modeling human parturition.
Specimen part, Time
View SamplesSeveral studies have shown that bone mineral density (BMD), a clinically measurable predictor of osteoporotic fracture, is the sum of genetic and environmental influences. In addition, serum IGF-1 levels have been correlated to both BMD and fracture risk. We previously identified a Quantitative Trait Locus (QTL) for Bone Mineral Density (BMD) on mouse Chromosome (Chr) 6 that overlaps a QTL for serum IGF-1. The B6.C3H-6T (6T) congenic mouse is homozygous for C57BL/6J (B6) alleles across the genome except for a 30 cM region on Chr 6 that is homozygous for C3H/HeJ (C3H) alleles. This mouse was created to study biology behind both the BMD and the serum IGF-1 QTLs and to identify the gene(s) underlying these QTLs. Female 6T mice have lower BMD and lower serum IGF-1 levels at all ages measured. As the liver is the major source of serum IGF-1, we examined differential expression in the livers of fasted female B6 and 6T mice by microarray.
A chromosomal inversion within a quantitative trait locus has a major effect on adipogenesis and osteoblastogenesis.
No sample metadata fields
View SamplesThe metabolic enzyme diglyceride acyltransferase (DGAT) is responsible for the synthesis of triglycerides. Loss of its expression may sensitize cells to conditions of nutrient and oxygen that are commonly present in tumors. This study is designed to identify stress response pathways that may be induced following the shRNA-mediated knockdown of the two genes coding for the DGAT enzymes. In vitro growth conditions lacking serum and oxygen were used to mimic growth conditions commonly found in poorly perfused tumor domains
Triglycerides Promote Lipid Homeostasis during Hypoxic Stress by Balancing Fatty Acid Saturation.
Specimen part, Cell line, Treatment
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