Aluminum toxicity is one of the major limiting factors for many crops worldwide. The primary symptom of Al toxicity syndrome is the inhibition of root growth, leading to poor water and nutrient absorption. The causes of this inhibition are still elusive, with several biochemical pathways being affected and with a significant variation between species. Most of the work done so far to investigate the genes responsible for Al tolerance used hydroponic culture. Here we evaluated plant responses using soil as substrate, which is a condition closer to the field reality.
Transcriptional profile of maize roots under acid soil growth.
Specimen part
View SamplesSpinal muscular atrophy (SMA) is one of the most common inherited forms of neurological disease leading to infant mortality. Patients exhibit selective loss of lower motor neurons resulting in muscle weakness, paralysis, and often death. Although patient fibroblasts have been used extensively to study SMA, motor neurons have a unique anatomy and physiology which may underlie their vulnerability to the disease process. Here we report the generation of induced pluripotent stem (iPS) cells from skin fibroblast samples taken from a child with SMA. These cells expanded robustly in culture, maintained the disease genotype, and generated motor neurons that showed selective deficits compared to those derived from the childs unaffected mother. This is the first study to show human iPS cells can be used to model the specific pathology seen in a genetically inherited disease. As such, it represents a promising resource to study disease mechanisms, screen novel drug compounds, and develop new therapies.
Induced pluripotent stem cells from a spinal muscular atrophy patient.
No sample metadata fields
View SamplesWe attempted to identify alterations in gene expression that occur during the progression from normal breast to ductal carcinoma in situ (DCIS) with the aim to elucidate significant genes and pathways underlying the premalignant transformation. To determine the expression changes that are common to multiple DCIS models (MCF10.DCIS, SUM102 and SUM225) and normal mammary epithelial cells (MCF10A), we grew the cells in three dimensional overlay culture with reconstituted basement membrane and used the extracted RNA for 76 cycles of deep sequencing (mRNA-Seq) using Illumina Genome Analyzer GAIIx. Analysis of mRNA-Seq results showed 295 consistently differentially expressed transcripts in DCIS models as compared to MCF10A. These differentially expressed genes are associated with a number of signaling pathways such as integrin, fibroblast growth factor and TGFß signaling. Many differentially expressed transcripts in DCIS were found to be involved in cell-cell signaling, cell-cell adhesion and cell proliferation. We further investigated ALDH5A1 gene that encodes for the enzyme, aldehyde dehydrogenase 5A1, which is involved in glutamate metabolism. Further, inhibition of ALDH5A1 with different pharmacological drugs resulted in significant inhibition of cell growth and proliferation in the DCIS models. Overall design: Four cell lines examined: normal mammary epithelial cell line (one sample) and three ductal carcinoma in situ cell lines (three samples). Each sample has two duplicates
RNA-Seq of human breast ductal carcinoma in situ models reveals aldehyde dehydrogenase isoform 5A1 as a novel potential target.
Disease, Cell line, Subject
View SamplesGeneration of human fibroblast-derived hepatocytes capable of extensive proliferation, as evidenced by significant liver repopulation of mice. Unlike current protocols for deriving hepatocytes from human fibroblasts, ours did not generate iPSCs, but shortcut reprogramming to pluripotency to generate an induced multipotent progenitor cell (iMPC) stage from which endoderm progenitor cells (iMPC-EPCs) and subsequently hepatocytes (iMPC-Heps) could be efficiently differentiated. After transplantation into an immune-deficient mouse model of human liver failure, iMPC-Heps were able to engraft and proliferate, and acquired levels of hepatocyte function similar to adult hepatocytes.
Mouse liver repopulation with hepatocytes generated from human fibroblasts.
Specimen part
View SamplesThe microarray analysis was designed to test the effects of HES5.3 siRNAs, Atoh7 siRNAs and nt siRNAs on gene expression in embryonic chick retina.
A positive feedback loop between ATOH7 and a Notch effector regulates cell-cycle progression and neurogenesis in the retina.
Age, Specimen part
View SamplesThe 6-hydroxydopamine (6OHDA) rat model of parkinsonism is among the first, and most commonly used, animal models of Parkinsons disease. It provides insight into the compensatory changes that occur in the brain after dopamine (DA) neuron degeneration. In order to better define the consequences of substantia nigra DA neuron loss on the neural and glial populations during and following nigrostriatal degeneration, tissue was collected and evaluated from the substantia nigra of 6OHDA or vehicle treated, or nave rats at 1, 2, 4, 6 & 16 weeks.
The longitudinal transcriptomic response of the substantia nigra to intrastriatal 6-hydroxydopamine reveals significant upregulation of regeneration-associated genes.
Sex, Specimen part
View SamplesmicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression by targeting specific mRNAs. Altered expression of circulating miRNAs have been associated with age-related diseases including cancer and cardiovascular disease. Although we and others have found an age-dependent decrease in miRNA expression in peripheral blood mononuclear cells (PBMCs), little is known about the role of circulating miRNAs in human aging. Here, we examined miRNA expression in human serum from young (mean age 30 years) and old (mean age 64 years) individuals using next generation sequencing technology and real-time quantitative PCR. Of the miRNAs that we found to be present in serum, three were significantly decreased in 20 older individuals compared to 20 younger individuals: miR-151a-5p, miR-181a-5p and miR-1248. Consistent with our data in humans, these miRNAs are also present at lower levels in the serum of elderly rhesus monkeys. In humans, miR-1248 was found to regulate the expression of mRNAs involved in inflammatory pathways and miR-181a was found to correlate negatively with the pro-inflammatory cytokines IL-6 and TNFa and to correlate positively with the anti-inflammatory cytokines TGFb and IL-10. These results suggest that circulating miRNAs may be a biological marker of aging and could also be important for regulating longevity. Identification of stable miRNA biomarkers in serum could have great potential as a noninvasive diagnostic tool as well as enhance our understanding of physiological changes that occur with age. Overall design: Examination of microRNAs isolated from human serum from 11 young (mean age 30 yrs) and 11 old (mean age 64 yrs) individuals and from peripheral blood mononuclear cells from one young (30 yr) and one old (64 yr) individual.
Age-related changes in microRNA levels in serum.
No sample metadata fields
View SamplesThe intestine is an organ with exceptionally high rate of cell turnover and perturbations in this process can lead to disease such as cancer or intestinal atrophy. Nutrition is a key factor regulating the intestinal cell turnover and has a profound impact on intestinal volume and cellular architecture. However, how the intestinal equilibrium is maintained in fluctuating dietary conditions is insufficiently understood. By utilizing the Drosophila midgut as a model, we reveal a novel nutrient sensing mechanism coupling stem cell metabolism with stem cell extrinsic growth signal. Our results show that intestinal stem cells (ISCs) employ the hexosamine biosynthesis pathway (HBP) to monitor nutritional status and energy metabolism. Elevated activity of the HBP promotes Warburg effect-like metabolic reprogramming, which is required for the reactivation of ISCs from calorie restriction-induced quiescence. Furthermore, the HBP activity is an essential facilitator for insulin signaling-induced intestinal growth. In conclusion, intestinal stem cell intrinsic nutrient sensing regulates metabolic pathway activities, and defines the stem cell responsiveness to niche-derived growth signals. Overall design: Intestinal mRNA profiles of 7 days old mated females of UAS-mCD8::GFP, hsFLP; tub-GAL4/+; FRT82B tub-GAL80/FRT82B genotype kept in calorie-restriction +/- 0.1M D-acetylglucosamine for 24h.
Stem Cell Intrinsic Hexosamine Metabolism Regulates Intestinal Adaptation to Nutrient Content.
Sex, Specimen part, Treatment, Subject
View SamplesDuring limb development, fibroblast growth factors (FGFs) govern proximal-distal outgrowth and patterning. FGFs also synchronize developmental patterning between the proximal-distal and anterior-posterior axes by maintaining sonic hedgehog (SHH) expression in cells of the zone of polarizing activity (ZPA) in the distal posterior mesoderm. SHH, in turn, maintains FGFs in the apical ectodermal ridge (AER) which caps the distal tip of the limb bud. Crosstalk between FGF and SHH signaling is critical for patterned limb development, but the mechanisms underlying this feedback loop are not well characterized.
LHX2 Mediates the FGF-to-SHH Regulatory Loop during Limb Development.
No sample metadata fields
View SamplesWhile long noncoding RNAs (lncRNAs) and mRNAs share similar biogenesis pathways, these two transcript classes differ in many regards. LncRNAs are less conserved, less abundant, and more tissue specific than mRNAs, implying that our understanding of lncRNA transcriptional regulation is incomplete. Here, we perform an in depth characterization of numerous factors contributing to this regulation. We find that lncRNA promoters contain fewer transcription factor binding sites than do those of mRNAs, with some notable exceptions. Surprisingly, we find that H3K9me3 –typically associated with transcriptional repression–is enriched at active lncRNA loci. However, the most discriminant differences between lncRNAs and mRNAs involve splicing: only half of lncRNAs are efficiently spliced, which can be partially attributed to defects in lncRNA splicing signals and diminished U2AF65 binding. These attributes are conserved between humans and mice. Finally, we find that certain transcriptional properties are enriched in known, functionally characterized lncRNAs, demonstrating that our multidimensional analysis might discern lncRNAs that are likely to be functional Overall design: Examination of RNA abundance in two cell lines (K562 and Hues9) and 5 time points after actinomycin D treatment. Three replicates per time point and cell type.
Chromatin environment, transcriptional regulation, and splicing distinguish lincRNAs and mRNAs.
Cell line, Subject, Time
View Samples