To better understand the mechanistic basis of aging and its relationship with retinal degeneration, we examined gene expression changes in aging rod photoreceptors. Rod photoreceptor cell death is a feature of normal retinal aging and is accelerated in many retinal degenerative diseases, including AMD, the leading cause of untreatable adult blindness in the United States and other western countries. To our knowledge, the examination of age-related gene expression changes in a specific neuronal cell-type is novel, and it has allowed us to identify significant age-related changes with better resolution than is possible with whole retina samples. We used flow cytometry and a transgenic mouse with GFP-tagged rod photoreceptors to purify this specific cell population, and gene expression changes were evaluated at three time points using microarrays and quantitative RT-PCR. Our results suggest that aging is progressive, beginning even in young adult mice. Although rod photoreceptors are highly specialized neurons, our analyses revealed changes in consensus pathways of aging, including oxidative phosphorylation and stress responses affecting transcription and inflammation. In addition, we identified stress response processes that may be especially relevant for the aging retina and retinal diseases, such as angiogenesis and nuclear receptor signaling pathways that affect retinoid and lipid metabolism.
Distinct signature of altered homeostasis in aging rod photoreceptors: implications for retinal diseases.
Age, Specimen part
View SamplesPurpose: To investigate the gene regulatory networks during photoreceptor differentiation.
Targeting of GFP to newborn rods by Nrl promoter and temporal expression profiling of flow-sorted photoreceptors.
No sample metadata fields
View SamplesSteer liver transcriptome
Differential expression of genes related to gain and intake in the liver of beef cattle.
Sex, Specimen part
View SamplesThe identification of a marker that is expressed in the conjunctival epithelium but not in the corneal epithelium has been a growing need. A more specific marker of limbal and conjunctival epithelia would be necessary to detect non-corneal epithelial cells on the corneal surface. To search for conjunctival specific marker(s), we first performed preferential gene profiling in the conjunctiva in direct comparison to that in the cornea using microarray technique.
Keratin 13 is a more specific marker of conjunctival epithelium than keratin 19.
Specimen part
View SamplesGoal was to identify yeast genes whose expression changed as a function of the shift from growth in bulk culture to growth in an air-liquid interfacial biofilm.
Ethanol-independent biofilm formation by a flor wine yeast strain of Saccharomyces cerevisiae.
Specimen part
View SamplesStem cell biology has garnered much attention due to its potential to impact human health through disease modeling and cell replacement therapy. This is especially pertinent to myelin-related disorders such as multiple sclerosis and leukodystrophies where restoration of normal oligodendrocyte function could provide an effective treatment. Progress in myelin repair has been constrained by the difficulty in generating pure populations of oligodendrocyte progenitor cells (OPCs) in sufficient quantities. Pluripotent stem cells theoretically provide an unlimited source of OPCs but significant advances are currently hindered by heterogeneous differentiation strategies that lack reproducibility. Here we provide a platform for the directed differentiation of pluripotent mouse epiblast stem cells (EpiSCs) through a defined series of developmental transitions into a pure population of highly expandable OPCs in ten days. These OPCs robustly differentiate into myelinating oligodendrocytes both in vitro and in vivo. Our results demonstrate that pluripotent stem cells can provide a pure population of clinically-relevant, myelinogenic oligodendrocytes and offer a tractable platform for defining the molecular regulation of oligodendrocyte development, drug screening, and potential cell-based remyelinating therapies.
Rapid and robust generation of functional oligodendrocyte progenitor cells from epiblast stem cells.
No sample metadata fields
View SamplesCell-based therapies for myelin disorders, such as multiple sclerosis and leukodystrophies, require technologies to generate functional oligodendrocyte progenitor cells. Here we describe direct conversion of mouse embryonic and lung fibroblasts to induced oligodendrocyte progenitor cells (iOPCs) using sets of either eight or three defined transcription factors. iOPCs exhibit a bipolar morphologyical and global gene expression profile molecular features consistent with bona fide OPCs. They can be expanded in vitro for at least five passages while retaining the ability to differentiate into induced multiprocessed oligodendrocytes. When transplanted to hypomyelinated mice, iOPCs are capable of ensheathing host axons and generating compact myelinmyelinating axons both in vitro and in vivo. Lineage conversion of somatic cells to expandable iOPCs provides a strategy to study the molecular control of oligodendrocyte lineage identity and may facilitate neurological disease modeling and autologous remyelinating therapies.
Transcription factor-mediated reprogramming of fibroblasts to expandable, myelinogenic oligodendrocyte progenitor cells.
Specimen part, Treatment
View SamplesComparison of gene expression profiles from C. elegans wildtype strain (N2) treated with L4440 and T25B9.1 RNAi for 5 days after L4 larvae stage. Jena Centre for Systems Biology of Ageing - JenAge (ww.jenage.de) Overall design: 6 samples in 2 groups: N2, L4440 5 days (3 Samples); N2, T25B9.1 5 days (3 Samples)
Impairing L-Threonine Catabolism Promotes Healthspan through Methylglyoxal-Mediated Proteohormesis.
Sex, Age, Specimen part, Cell line, Subject
View SamplesSelective genetic ablation of the SIRT1 deacetylase domain in skeletal muscle results in increased H4K16 acetylation and deregulated activation of the myogenic program in satellite cells Overall design: To establish the role of the deacetylase SIRT1 in skeletal muscle we examined the genome wide distribution of H4K16ac in quiescent (FI) and proliferating (Cul) satellite cells isolated from WT mice (C57Bl/6 background) and SIRT1mKO (generated via breeding of Pax7cre/+ knock-in mice with mice containing the floxed exon 4 SIRT1 allele). We also analyzed the distribution of SIRT1 in quiescent and proliferating FACS isolated WT satellite cells (two replicates). We generated the mRNA profiles (at least two replicate for each experiment) of FACS isolated quiescent, proliferating and differentiating (1 day in differentiation medium) satellite cells of WT mice and SIRT1mKO. The selective genetic ablation of the SIRT1 deacetylase domain in skeletal muscle results in increased H4K16 acetylation and deregulated activation of the myogenic program.
The NAD(+)-dependent SIRT1 deacetylase translates a metabolic switch into regulatory epigenetics in skeletal muscle stem cells.
No sample metadata fields
View SamplesPolymorphonuclear leukocytes (PMN) from patients with chronic granulomatous disease (CGD) fail to produce microbicidal concentrations of reactive oxygen species due to mutations in NOX2. Patients with CGD suffer from severe, life-threatening infections and inflammatory complications. Granulibacter bethesdensis is an emerging Gram-negative pathogen in CGD that resists killing by CGD PMN and inhibits PMN apoptosis through unknown mechanisms. Microarray analysis was used to study mRNA expression in normal and CGD PMN during incubation with G. bethesdensis and, simultaneously, in G. bethesdensis with normal and CGD PMN. We detected upregulation of anti-apoptotic genes (e.g., XIAP, GADD45B) and downregulation of pro-apoptotic genes (e.g., CASP8, APAF1) in infected PMN. Transcript and protein levels of inflammation and immunity-related genes were also altered. Upon interaction with PMN, G. bethesdensis altered expression of ROS-resistance genes in the presence of normal but not CGD PMN. Bacterial stress response genes, including ClpB, increased during phagocytosis by both normal and CGD PMN demonstrating responses to oxygen-independent PMN antimicrobial systems. Antisense knock down demonstrated that ClpB is dispensable for extracellular growth but is essential for bacterial resistance to both normal and CGD PMN. Metabolic adaptation of Granulibacter growth in PMN included upregulation of pyruvate dehydrogenase. Pharmacologic inhibition of pyruvate dehydrogenase by triphenylbismuthdichloride was lethal to Granulibacter. This study expands knowledge of microbial pathogenesis by Granulibacter in cells from permissive (CGD) and non-permissive (normal) hosts and identifies potentially druggable microbial factors, such as pyruvate dehydrogenase and ClpB, to help combat this antibiotic-resistant pathogen.
Simultaneous Host-Pathogen Transcriptome Analysis during Granulibacter bethesdensis Infection of Neutrophils from Healthy Subjects and Patients with Chronic Granulomatous Disease.
Specimen part, Disease, Disease stage, Time
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