Purpose: Investigate the molecular determinants of retinal regeneration in adult vertebrates by analyzing the gene expression profiles of control and post-lesion retina of adult zebrafish, a system that regenerates following injury.
Gene expression profiles of intact and regenerating zebrafish retina.
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View SamplesSince the discovery of radial glia as the source of neurons, their heterogeneity in regard to neurogenesis has been described by clonal and time-lapse analysis in vitro. However, the molecular determinants specifying neurogenic radial glia differently from radial glia that mostly self-renew remain ill-defined. Here, we isolated two radial glial subsets that co-exist at mid-neurogenesis in the developing cerebral cortex and their immediate progeny. While one subset generates neurons directly, the other is largely non-neurogenic but also gives rise to Tbr2-positive basal precursors, thereby contributing indirectly to neurogenesis. Isolation of
Prospective isolation of functionally distinct radial glial subtypes--lineage and transcriptome analysis.
No sample metadata fields
View SamplesEvolution of the mammalian brain encompassed a remarkable increase in size of cerebral cortex, including tangential and radial expansion, but the mechanisms underlying these key parameters are still largely unknown. Here, we identified the novel DNA associated protein TRNP1 as a regulator of cerebral cortical expansion in both these dimensions. Gain and loss of function experiments in the mouse cerebral cortex in vivo demonstrate that high Trnp1 levels promote neural stem cell self-renewal and tangential expansion, while lower levels promote radial expansion resulting in a potent increase in the generation of intermediate progenitors and outer radial glial cells resulting in folding of the otherwise smooth murine cerebral cortex. Remarkably, TRNP1 expression levels exhibit regional differences also in the cerebral cortex of human fetuses anticipating radial or tangential expansion respectively. Thus, the dynamic regulation of TRNP1 is critical to regulate tangential and radial expansion of the cerebral cortex in mammals.
Prospective isolation of functionally distinct radial glial subtypes--lineage and transcriptome analysis.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Molecular Aging of Human Liver: An Epigenetic/Transcriptomic Signature.
Sex, Age, Specimen part, Disease
View SamplesGene expression profiling of liver biopsies collected from 33 healthy liver donors ranging from 13 to 90 years old. The Affymetrix HG-U133 Plus 2.0 GeneChip platform was used to evaluate gene-expression.
Molecular Aging of Human Liver: An Epigenetic/Transcriptomic Signature.
Sex, Age, Specimen part, Disease
View SamplesLow-oxygen tolerance is supported by an adaptive response that includes a coordinate shift in metabolism and the activation of a transcriptional program that is driven by the hypoxia-inducible factor (HIF) pathway. The precise contribution of HIF-1 in the adaptive response, however, has not been determined. Here we investigate how HIF-1 influences hypoxic adaptation throughout Drosophila development. We find that hypoxic-induced transcriptional changes are comprised of HIF-dependent and HIF-independent pathways that are distinct and separable. We show that normoxic set-points of carbohydrate metabolites are significantly altered in dHIF mutants and that these animals are unable to mobilize glycogen in hypoxia. Furthermore, we find that the estrogen-related receptor (dERR), which is a global regulator of aerobic glycolysis in larvae, is required for a competent hypoxic response. dERR binds to dHIF and participates in the HIF-dependent transcriptional program in hypoxia. In addition, dERR acts in the absence of dHIF in hypoxia and a significant portion of HIF-independent transcriptional responses can be attributed to dERR actions, including upregulation of glycolytic transcripts. These results indicate that competent hypoxic responses arise from complex interactions between HIF-dependent and -independent mechanisms, and that dERR plays a central role in both of these programs.
HIF- and non-HIF-regulated hypoxic responses require the estrogen-related receptor in Drosophila melanogaster.
Specimen part
View SamplesMethods: RNA-seq libraries were prepared using the Illumina TruSeq technology. The libraries were quantified and samples were multiplexed in each lane of the flowcell. Cluster generation was performed and then sequenced on the Illumina HiSeq2500 system. Reads were mapped on the Human Genome Reference (GRCh38) and normalized expression table was generated. Results: Among differentially expressed genes, compared with DMSO-treated hiPSC-CMs, 505 genes were upregulated in FM+WY+TID-treated hiPSC-CMs, with 72 genes commonly upregulated in both FM+WY+TID-treated hiPSC-CMs and LV groups and 949 genes were downregulated in FM+WY+TID-treated hiPSC-CMs and 2137 genes were downregulated in LV, with 437 genes downregulated in both FM+WY+TID-treated hiPSC-CMs and LV compared with DMSO-treated hiPSC-CMs . Conclusions: Data demonstrate increased expression of genes associated with many metabolic processes which are also highly enriched in human pediatric heart samples including many interconnected metabolic processes that are upstream of lipid metabolism and FAO, agreeing with the shift to FAO for energy utilization in more mature CMs, and decreased expression of genes involved in developmental processes, adhesion and signaling in both FM+WY+TID-treated hiPSC-CMs and LV. The overlap in both upregulated and downregulated genes in both groups confirmed an advanced degree of cardiomyocyte maturation in response to FM+WY+TID. Overall design: RNA-sequencing analysis was performed to compare global gene expression profiles of hiPSC-CMs at differentiation day 28 with maturation factors (FM+WY+TID) treatment (Treat) vs. DMSO treatment (DMSO) vs. left ventricle tissue sample (LV).
Targeting HIF-1α in combination with PPARα activation and postnatal factors promotes the metabolic maturation of human induced pluripotent stem cell-derived cardiomyocytes.
Specimen part, Subject
View SamplesThe neuronal ceroid lipofuscinoses (NCL) are a group of childhood inherited neurodegenerative disorders characterized by blindness, early dementia and pronounced cortical atrophy. The similar pathological and clinical profiles of different forms of NCL suggest that common disease mechanisms may be involved. Here, we have performed quantitative gene expression profiling of cortex from targeted knock out mice produced for Cln1 and Cln5 to explore NCL-associated molecular pathways. Combined microarray datasets from both mouse models exposed a common affected pathway: genes regulating cytoskeletal dynamics and neuronal growth cone stabilization display similar aberrations. We analyzed locus specific gene expression and showed regional clustering of Cln1 and three major genes of this pathway, further supporting a close functional relationship between the corresponding gene products, Cap1, Ptprf and Ptp4a2. The evidence from the gene expression data was substantiated by immunohistochemical staining data of Cln1-/- and Cln5-/- cortical neurons. These primary neurons displayed abnormalities in beta-tubulin and actin as well as abnormal intracellular distribution of growth cone associated proteins GAP-43, synapsin and Rab3. Our data provide the first evidence for a common molecular pathogenesis behind neuronal degeneration in CLN1 and CLN5. Since CLN1 and CLN5 code for proteins with distinct functional roles these data may have implications for other forms of NCL.
Brain gene expression profiles of Cln1 and Cln5 deficient mice unravels common molecular pathways underlying neuronal degeneration in NCL diseases.
Sex, Age, Specimen part, Disease
View SamplesReprogramming of somatic cells is a valuable tool to understand the mechanisms of regaining pluripotency and further opens up the possibility of generating patient-specific pluripotent stem cells. Reprogramming of mouse and human somatic cells into pluripotent stem cells, designated as induced pluripotent stem (iPS) cells, has been possible with the expression of the transcription factor quartet Oct4 (also known as Pou5f1), Sox2, c-Myc, and Klf4. Considering that ectopic expression of c-Myc causes tumourigenicity in offspring and retroviruses themselves can cause insertional mutagenesis, the generation of iPS cells with a minimal number of factors may hasten the clinical application of this approach. Here, we show that adult mouse neural stem cells express higher endogenous levels of Sox2 and c-Myc than embryonic stem cells, and that exogenous Oct4 together with either Klf4 or c-Myc are sufficient to generate iPS cells from neural stem cells. These two-factor (2F) iPS cells are similar to embryonic stem cells at the molecular level, contribute to development of the germ line, and form chimeras. We propose that, in inducing pluripotency, the number of reprogramming factors can be reduced when using somatic cells that endogenously express appropriate levels of complementing factors.
Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors.
No sample metadata fields
View SamplesTopoisomerase 1 (TOP1) poisons like camptothecin (CPT), which are used as chemotherapeutic agents in cancer, elicit DNA damage in quiescient neurons. In this study, we examined the effects of CPT and actinomycin D (ActD) on neuronal cells. Motor (MNs) and cortical (CNs) neurons were more susceptible to the toxic effects of CPT and ActD than fibroblasts. MNs and CNs exhibited a delayed DNA damage responseincrease in nuclear -H2AX focirelative to fibroblasts. Neuronal cells expressed higher levels of Top1 mRNA than fibroblasts which could explain their enhanced vulnerability to CPT and ActD toxicity. Microarray analysis was performed to identify differentially regulated transcripts in MNs treated with CPT for 2 hours. Many immediate-early genes including Fos and Egr-1 were upregulated in CPT-treated MNs. Fos mRNA levels were elevated in all cells types treated with CPT; Egr-1 transcript levels, however, were reduced in CPT-treated fibroblasts even though they were elevated in treated MNs and CNs. Pathway and network analysis of the differentially expressed transcripts revealed activation of ERK and JNK signaling cascades in CPT-treated MNs. In conclusion, MNs were more vulnerable than fibroblasts to the damaging effects of TOP1 poisons and they elicit a unique intracellular response to CPT treatment.
Identification of early gene expression changes in primary cultured neurons treated with topoisomerase I poisons.
Specimen part, Treatment
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