Suppressor of cytokine signaling 3 (SOCS3) down-regulates several signaling pathways in multiple cell types, and previous data suggest that SOCS3 may shut off cytokine activation at the early stages of liver regeneration. We developed hepatocyte-specific Socs3 knockout (Socs3 h-KO) mice to directly study the role of SOCS3 during liver regeneration after 2/3 partial hepatectomy (PH). Socs3 h-KO mice demonstrate marked enhancement of DNA replication and liver weight restoration after 2/3 PH in comparison with littermate controls. Without SOCS3, signal transducer and activator of transcription 3 (STAT3) phosphorylation is prolonged, and activation of the mitogenic kinases extracellular signal-regulated kinase 1/2 (ERK1/2) is enhanced after PH. In vitro, we show that SOCS3 deficiency enhances hepatocyte proliferation in association with enhanced STAT3 and ERK activation after epidermal growth factor (EGF) or interleukin 6 (IL-6) stimulation. Microarray analyses show that SOCS3 modulates a distinct set of genes after PH, which fall into diverse physiologic categories. Using a model of chemical-induced carcinogenesis, we found that Socs3 h-KO mice develop hepatocellular carcinoma (HCC) at an accelerated rate. By acting on cytokines and multiple proliferative pathways, SOCS3 modulates both physiologic and neoplastic proliferative processes in the liver, and may act as a tumor suppressor.
Regulation of liver regeneration and hepatocarcinogenesis by suppressor of cytokine signaling 3.
No sample metadata fields
View SamplesLiver cirrhosis is a strong risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes patients to tumorigenesis are not well understood. Transgenic mice expressing platelet-derived growth factor C (Pdgf-c) under the control of the albumin promoter provide a unique animal model that mimics the step-wise disease progression in humans from fibrosis to HCC. The livers of Pdgf-c Tg mice show evidence of liver injury, including inflammation, proliferation, fibrosis and steatosis, and as the mice age, angiogenesis and dysplasia. Eighty-five percent of these mice develop HCC spontaneously, and have reduced survival that is related to their liver pathology. Through measurement of protein, RNA, and histological markers, we provide evidence to support the hypothesis that changes in liver stromal cells play an essential role in tumorigenesis in this model. A paracrine signaling model is proposed where ectopic expression of Pdgf-c in hepatocytes results in activation of hepatic stellate cells, which subsequently activates endothelial and Kupffer cells. Activation of these non-parenchymal cells promotes the release of hepatocyte growth factors that, together with changes in extracellular matrix, lead to the formation of HCC. Pdgf-c Tg mice provide a useful pre-clinical model in which to test novel drugs for chronic liver disease and HCC that focus on blocking the processes that alter the liver's fibrotic microenvironment.
Paracrine activation of hepatic stellate cells in platelet-derived growth factor C transgenic mice: evidence for stromal induction of hepatocellular carcinoma.
Specimen part
View SamplesSustained Akt activation induces cardiac hypertrophy (LVH), which may lead to heart failure. This study tested the hypothesis that Akt activation contributes to mitochondrial dysfunction in pathological LVH. Akt activation induced LVH and progressive repression of mitochondrial fatty acid oxidation (FAO) pathways. Preventing LVH by inhibiting mTOR failed to prevent the decline in mitochondrial function but glucose utilization was maintained. Akt activation represses expression of mitochondrial regulatory, FAO, and oxidative phosphorylation genes in vivo that correlate with the duration of Akt activation in part by reducing FOXO-mediated transcriptional activation of mitochondrial-targeted nuclear genes in concert with reduced signaling via PPAR/PGC-1 and other transcriptional regulators. In cultured myocytes Akt activation disrupted mitochondrial bioenergetics, which could be partially reversed by maintaining nuclear FOXO, but not by increasing PGC-1. Thus, although short-term Akt activation may be cardioprotective during ischemia by reducing mitochondrial metabolism and increasing glycolysis, long-term Akt activation in the adult heart contributes to pathological LVH in part by reducing mitochondrial oxidative capacity.
Enhanced cardiac Akt/protein kinase B signaling contributes to pathological cardiac hypertrophy in part by impairing mitochondrial function via transcriptional repression of mitochondrion-targeted nuclear genes.
Age, Specimen part
View SamplesTissues of Arabidopsis plants overexpressing artificial microRNAs were compared to wild_type and respective target gene mutants (duplicate arrays)
Highly specific gene silencing by artificial microRNAs in Arabidopsis.
Specimen part
View SamplesThe pre-synaptic protein -synuclein is a key player in the pathogenesis of Parkinson's disease. Together with accumulation and missfolding of -synuclein protofibrils serve as seed structures for the aggregation of numerous proteins in the cytoplasm of neuronal cells, the so-called Lewy bodies. Furthermore, missense mutations in the SNCA gene and gene multiplications lead to autosomal dominant forms of familiar PD. However, so far the exact biological role of -synuclein in normal brain is elusive. To gain more insights into the biological function of this protein we monitored whole genome expression changes in dopaminergic neuroblastoma cells (SH-SY5Y) caused by a 90% reduction of -synuclein by RNA interference.
Microarray expression analysis of human dopaminergic neuroblastoma cells after RNA interference of SNCA--a key player in the pathogenesis of Parkinson's disease.
No sample metadata fields
View SamplesSMART-seq2 was performed on single cells isolated from visually staged zebrafish embryos. Overall design: Samples were all sequenced in one batch. Some were generated with a 5'' UMI-tagged method, and others are full-length SMART-seq2.
Single-cell reconstruction of developmental trajectories during zebrafish embryogenesis.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Characterisation of cisplatin-induced transcriptomics responses in primary mouse hepatocytes, HepG2 cells and mouse embryonic stem cells shows conservation of regulating transcription factor networks.
Cell line, Treatment, Time
View SamplesWild-type zebrafish embryos were mechanically dissociated and profiled using Drop-seq Overall design: Drop-seq was performed on 28 groups of 20-40 visually staged, mechanically dissociated embryos. Samples were combined and sequenced in batches DS2-DS5.
Single-cell reconstruction of developmental trajectories during zebrafish embryogenesis.
Subject
View SamplesSubstantial effort is currently devoted to identifying cancer-associated alterations using genomics. Here, we show that standard blood collection procedures rapidly change the transcriptional and post-transcriptional landscapes of hematopoietic cells, resulting in biased activation of specific biological pathways, up-regulation of pseudogenes, antisense RNAs, and unannotated coding isoforms, and RNA surveillance inhibition. Affected genes include common mutational targets and thousands of other genes participating in processes such as chromatin modification, RNA splicing, T and B cell activation, and NF-?B signaling. The majority of published leukemic transcriptomes exhibit signals of this incubation-induced dysregulation, explaining up to 40% of differences in gene expression and alternative splicing between leukemias and reference normal transcriptomes. The effects of sample processing are particularly evident in pan-cancer analyses. We provide biomarkers that detect prolonged incubation of individual samples, and show that keeping blood on ice markedly reduces changes to the transcriptome. In addition to highlighting the potentially confounding effects of technical artifacts in cancer genomics data, our study emphasizes the need to survey the diversity of normal as well as neoplastic cells when characterizing tumors. This study is complemented by GSE61410: transcriptomic profiling of bone marrow cells from healthy individuals. Overall design: Peripheral blood mononuclear cells (PBMCs) were isolated from four healthy individuals, following an ex vivo incubation of variable length at either room temperature or on ice. RNA transcriptomes were measured using the Illumina HiSeq.
Sample processing obscures cancer-specific alterations in leukemic transcriptomes.
No sample metadata fields
View SamplesThe transcriptomic changes induced in the human liver cell line HepG2 by 7M of cisplatin after treatment for 12, 24 and 48h
Characterisation of cisplatin-induced transcriptomics responses in primary mouse hepatocytes, HepG2 cells and mouse embryonic stem cells shows conservation of regulating transcription factor networks.
Cell line, Treatment, Time
View Samples