Kidney transplants that develop dysfunction or proteinuria after one year post transplant are at considerable risk for progression to renal failure. Identifying the molecules associated with graft failure could potentially lead to interventions that would slow the progression of organ failure.
A molecular classifier for predicting future graft loss in late kidney transplant biopsies.
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View SamplesCell migration is central to many biological processes including embryonic development, wound healing, and cancer progression. Cell migration is sensitive to environmental stiffness, and many cell types exhibit a stiffness optimum at which migration is maximal. Here we present a cell migration simulator that predicts a stiffness optimum that can be shifted by altering the number of active molecular motors and clutches. This prediction is verified experimentally by comparing cell traction and F-actin retrograde flow for two cell types with differing amounts of active motors and clutches: embryonic chick forebrain neurons (ECFNs; optimum ~1 kPa) and U251 glioma cells (optimum ~100 kPa). In addition, the model predicts, and experiments confirm, that the stiffness optimum of U251 glioma cell migration, morphology, and F-actin retrograde flow rate can be shifted to lower stiffness by simultaneous drug inhibition of myosin II motors and integrin-mediated adhesions.
Shifting the optimal stiffness for cell migration.
Sex, Cell line
View SamplesProtein synthesis belongs to the most energy consuming processes in the cell. Lowering oxygen tension below normal (hypoxia) causes a rapid inhibition of global mRNA translation due to the decreased availability of energy. Interestingly, subsets of mRNAs pursue active translation under such circumstances. In human fibrosarcoma cells (HT1080) exposed to prolonged hypoxia (36 h, 1% oxygen) we observed that transcripts are either increasingly or decreasingly associated with ribosomes localized at the endoplasmic reticulum (ER). In a global setting it turned out that only 31% of transcripts showing elevated total-RNA levels were also increasingly present at the ER in hypoxia. These genes, regulated by its expression as well as its ER-localization, belong to the gene ontologys hypoxia response, glycolysis and HIF-1 transcription factor network supporting the view of active mRNA translation at the ER during hypoxia. Interestingly, a large group of RNAs was found to be unchanged at the expression level, but translocate to the ER in hypoxia. Among these are transcripts encoding translation factors and >180 ncRNAs. In summary, we provide evidence that protein synthesis is favoured at the ER and, thus, partitioning of the transcriptome between cytoplasmic and ER associated ribosomes mediates adaptation of gene expression in hypoxia.
Hypoxia-induced gene expression results from selective mRNA partitioning to the endoplasmic reticulum.
Specimen part, Cell line
View SamplesWe generated gene expression profiles of 5 time points in murine lung development (E11.5, E13.5, E14.5, E16.5 and P5). The goal of this study was to establish a reference data set for exploration of large-scale similarities between transcriptomes in development and cancer.
Analysis of gene expression in a developmental context emphasizes distinct biological leitmotifs in human cancers.
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View SamplesOBJECTIVE: To characterize the hormonal milieu and adipose gene expression in response to catch-up growth (CUG), a growth pattern associated with obesity and diabetes risk, in a mouse model of low birth weight (LBW). RESEARCH DESIGN AND METHODS: ICR mice were food restricted by 50% from gestational days 12.5-18.5, reducing offspring birth weight by 25%. During the suckling period, dams were either fed ad libitum, permitting CUG in offspring, or food restricted, preventing CUG. Offspring were killed at age 3 weeks, and gonadal fat was removed for RNA extraction, array analysis, RT-PCR, and evaluation of cell size and number. Serum insulin, thyroxine (T4), corticosterone, and adipokines were measured.
Accelerated postnatal growth increases lipogenic gene expression and adipocyte size in low-birth weight mice.
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An aberrant transcription factor network essential for Wnt signaling and stem cell maintenance in glioblastoma.
Specimen part, Cell line
View SamplesGlioblastoma (GBM) is thought to be driven by a sub-population of cancer stem cells (CSCs) that self-renew and recapitulate tumor heterogeneity, yet remain poorly understood. Here we present a comparative epigenomic analysis of GBM CSCs that reveals widespread activation of genes normally held in check by Polycomb repressors. These activated targets include a large set of developmental transcription factors (TFs) whose coordinated activation is unique to the CSCs. We demonstrate that a critical factor in the set, ASCL1, activates Wnt signaling by repressing the negative regulator DKK1. We show that ASCL1 is essential for maintenance and in vivo tumorigenicity of GBM CSCs. Genomewide binding profiles for ASCL1 and the Wnt effector LEF1 provide mechanistic insight and suggest widespread interactions between the TF module and the signaling pathway. Our findings demonstrate regulatory connections between ASCL1, Wnt signaling and collaborating TFs that are essential for the maintenance and tumorigenicity of GBM CSCs.
An aberrant transcription factor network essential for Wnt signaling and stem cell maintenance in glioblastoma.
Cell line
View SamplesBranched-chain amino acids (BCAA) have emerged as predictors of type 2 diabetes (T2D). However, their potential role in the pathogenesis of insulin resistance and T2D remains unclear. By integrating data from skeletal muscle gene expression and metabolomic analyses, we demonstrate evidence for perturbation in BCAA metabolism and fatty acid oxidation in skeletal muscle from insulin-resistant humans. Experimental modulation of BCAA flux in cultured cells alters fatty acid oxidation in parallel. Furthermore, heterozygosity for the BCAA metabolic enzyme methylmalonyl-CoA mutase (MUT) alters muscle lipid metabolism in vivo, resulting in increased muscle triacylglycerol (TAG) accumulation and increased body weight after high-fat feeding. Together, our results demonstrate that impaired muscle BCAA catabolism may contribute to the development of insulin resistance by reducing fatty acid oxidation and increasing TAG accumulation.
Defects in muscle branched-chain amino acid oxidation contribute to impaired lipid metabolism.
Sex, Age, Specimen part, Treatment
View SamplesA/J mice are genetically predisposed to spontaneous and/or chemically-induced lung tumors while C57BL/6J (B6) mice are resistant. This genetic disparity provides a unique scenario to identify molecular mechanisms associated with the lung response to welding fume at the transcriptome level.
Response of the mouse lung transcriptome to welding fume: effects of stainless and mild steel fumes on lung gene expression in A/J and C57BL/6J mice.
Treatment
View SamplesThis experiment was conducted to test multiple hypotheses: 1) long-wave 365 nm UV light exposure at low fluences does not alter gene expression of hMSC, 2) presence of radical species during polymerization causes DNA damage in hMSC, 3) 3D encapsulation of hMSC causes changes in gene expression of hMSC compared with traditional 2D culture, 4) Differencesin 3D hydrogel networks induce gene expression changes in hMSC
Low-Dose, Long-Wave UV Light Does Not Affect Gene Expression of Human Mesenchymal Stem Cells.
Specimen part
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