SUMMARY: This article presents a predictive molecular signature that marks the early onset of fibrosis in a translational nonalcoholic steatohepatitis mouse model. Overlap of genes and processes with human nonalcoholic steatohepatitis and a list of top candidate biomarkers for early fibrosis are described. BACKGROUND & AIMS: The incidence of nonalcoholic steatohepatitis (NASH) is increasing. The pathophysiological mechanisms of NASH and the sequence of events leading to hepatic fibrosis are incompletely understood. The aim of this study was to gain insight into the dynamics of key molecular processes involved in NASH and to rank early markers for hepatic fibrosis. METHODS: A time-course study in low-density lipoprotein–receptor knockout. Leiden mice on a high-fat diet was performed to identify the temporal dynamics of key processes contributing to NASH and fibrosis. An integrative systems biology approach was used to elucidate candidate markers linked to the active fibrosis process by combining transcriptomics, dynamic proteomics, and histopathology. The translational value of these findings were confirmed using human NASH data sets. RESULTS: High-fat-diet feeding resulted in obesity, hyperlipidemia, insulin resistance, and NASH with fibrosis in a time-dependent manner. Temporal dynamics of key molecular processes involved in the development of NASH were identified, including lipid metabolism, inflammation, oxidative stress, and fibrosis. A data-integrative approach enabled identification of the active fibrotic process preceding histopathologic detection using a novel molecular fibrosis signature. Human studies were used to identify overlap of genes and processes and to perform a network biology-based prioritization to rank top candidate markers representing the early manifestation of fibrosis. CONCLUSIONS: An early predictive molecular signature was identified that marked the active profibrotic process before histopathologic fibrosis becomes manifest. Early detection of the onset of NASH and fibrosis enables identification of novel blood-based biomarkers to stratify patients at risk, development of new therapeutics, and help shorten (pre)clinical experimental time frames. Keywords: Systems Biology; Metabolic Syndrome; Liver Disease; Diagnosis. Overall design: In total 9 treatment groups: 5 Control groups (chow = standard diet; t=0, 6, 12, 18, 24 weeks), 4 Treatment groups (HFD = High Fat diet; 6, 12, 18, 24 weeks).
Uncovering a Predictive Molecular Signature for the Onset of NASH-Related Fibrosis in a Translational NASH Mouse Model.
Specimen part, Subject
View SamplesTwenty-one genes (27 probe sets) were up-regulated in CAF, as compared with NF. Known functions of these genes relate to paracrine or intracellular signaling, transcriptional regulation, extracellular matrix and cell adhesion/migration. Ten genes (14 probe sets) were down-regulated in CAF, including the pluripotency transcription factor KLF4. Quantitative RTPCR analysis of 10 genes validated the array results. Immunohistochemical staining for three gene products confirmed stromal expression in terms of location and relative quantity. Surprisingly, the variability of gene expression was slightly higher in NF than in CAF, suggesting inter-individual heterogeneity of normal stroma.
Heterogeneity of gene expression in stromal fibroblasts of human breast carcinomas and normal breast.
Specimen part
View SamplesWe report the first RNA-Seq experiments profiling the effects of DEK loss in HNSCC. Our data also incorporates HPV+ and HPV- tumors to idenfity HPV-dependent and -independent gene signatures. Overall design: RNA-Seq of DEK-dependent gene signatures in HNSCC cell lines
IRAK1 is a novel DEK transcriptional target and is essential for head and neck cancer cell survival.
No sample metadata fields
View SamplesTranscriptomic profiling of complex tissues by single-nucleus RNA-sequencing (snRNA-seq) affords some advantages over single-cell RNA-sequencing (scRNA-seq). snRNA-seq provides less biased cellular coverage, does not appear to suffer cell isolation-based transcriptional artifacts, and can be applied to archived frozen specimens. We used well-matched snRNA-seq and scRNA-seq datasets from mouse visual cortex to compare cell type detection. Although more transcripts are detected in individual whole cells (~11,000 genes) than nuclei (~7,000 genes), we demonstrate that closely related neuronal cell types can be similarly discriminated with both methods if intronic sequences are included in snRNA-seq analysis. We estimate that the nuclear proportion of total cellular mRNA varies from 20% to over 50% for large and small pyramidal neurons, respectively. Together, these results illustrate the high information content of nuclear RNA for characterization of cellular diversity in brain tissues. Overall design: scRNA-seq of 463 single nuclei and 463 matched single cells from mouse primary visual cortex (VISp) and 30 control samples. Note that single cell data respresents a small subset of VISp cells from GEO series GSE115746.
Single-nucleus and single-cell transcriptomes compared in matched cortical cell types.
Subject
View SamplesMessenger RNA is thought to predominantly reside in the cytoplasm, where it is translated and eventually degraded. Although nuclear retention of mRNA has a regulatory potential it is considered extremely rare in mammals. Here to explore the extent of mRNA retention in metabolic tissues we combine deep sequencing of nuclear and cytoplasmic RNA fractions with single molecule transcript imaging in mouse beta cells, liver and gut. We identify a wide range of protein coding genes for which the levels of spliced polyadenylated mRNA are higher in the nucleus than in the cytoplasm. These include genes such as the transcription factor ChREBP, Nlrp6, Glucokinase and Glucagon receptor. We demonstrate that nuclear retention of mRNA can efficiently buffer cytoplasmic transcript levels from noise that emanates from transcriptional bursts. Our study challenges the view that transcripts predominantly reside in the cytoplasm and reveals a role of the nucleus in dampening gene expression noise. Overall design: we have total of 8 samples all are mice. liver nuclear RNA (2 replicates), liver cytoplasmic RNA (2 replicates), MIN6 (cell line) nuclear RNA (2 replicates), MIN6 (cell line) cytoplasmic RNA (2 replicates)
Nuclear Retention of mRNA in Mammalian Tissues.
Specimen part, Cell line, Subject
View SamplesCerebellum from post-natal day 11 L1 knockout mice on the 129Sv background were compared to wild type littermates. The original goal of the study was to determine if there was compensation from other L1 family members or alterations in cell survival or apoptosis. Interestingly no major changes were detected in those families or pathways.
A modifier locus on chromosome 5 contributes to L1 cell adhesion molecule X-linked hydrocephalus in mice.
Sex
View SamplesThe use of microbiological cultures for diagnosing bacterial infections in young febrile infants have substantial limitations, including false positive and false negative cultures, and non-ideal turn-around times. Analysis of host genomic expression patterns (RNA biosignatures) in response to the presence of specific pathogens, however, may provide an alternate and potentially improved diagnostic approach. This study was designed to define bacterial and non-bacterial RNA biosignatures to distinguish these infections in young febrile infants.
Association of RNA Biosignatures With Bacterial Infections in Febrile Infants Aged 60 Days or Younger.
Sex, Age, Specimen part, Race
View SamplesHeat stress is one of the most prominent and deleterious environmental threads affecting plant growth and development. Upon high temperatures, plants launch specialized gene expression programs that promote stress protection and survival. These programs involve global and specific changes at the transcriptional and translational levels. However the coordination of these processes and their specific role in the establishment of the heat stress response is not fully elucidated.
Analysis of genome-wide changes in the translatome of Arabidopsis seedlings subjected to heat stress.
Specimen part
View SamplesRecent reports have proposed a new paradigm for obtaining mature somatic cell types from fibroblasts without going through a pluripotent state, by briefly expressing canonical iPSC reprogramming factors Oct4, Sox2, Klf4 and c-Myc (abbreviated as OSKM), in cells expanded in lineage differentiation promoting conditions. Here we apply genetic lineage tracing for endogenous Nanog, Oct4 and X chromosome reactivation during OSKM induced trans-differentiation, as these molecular events mark final stages for acquisition of induced pluripotency. Remarkably, the vast majority of reprogrammed cardiomyocytes or neural stem cells derived from mouse fibroblasts via OSKM mediated trans-differentiation were attained after transient acquisition of pluripotency, and followed by rapid differentiation. Our findings underscore a molecular and functional coupling between inducing pluripotency and obtaining “trans-differentiated” somatic cells via OSKM induction, and have implications on defining molecular trajectories assumed during different cell reprogramming methods. Overall design: poly RNA-Seq was measured before, during and after conversion of mouse embryonic fibroblasts to neural stem cells using OSKM trans-differentiation method.
Transient acquisition of pluripotency during somatic cell transdifferentiation with iPSC reprogramming factors.
No sample metadata fields
View SamplesWhen assembling a nephron during development a multipotent stem cell pool becomes restricted as differentiation ensues. A faulty differentiation arrest in this process leads to transformation and initiation of a Wilms'' tumor. Mapping these transitions with respective surface markers affords accessibility to specific cell subpopulations. NCAM1 and CD133 have been previously suggested to mark human renal progenitor populations. Herein, using cell sorting, RNA sequencing, in vitro studies with serum-free media and in vivo xenotransplantation we demonstrate a sequential map that links human kidney development and tumorigenesis; In nephrogenesis, NCAM1+CD133- marks SIX2+ multipotent renal stem cells transiting to NCAM1+CD133+ differentiating segment-specific SIX2- epithelial progenitors and NCAM1-CD133+ differentiated nephron cells. In tumorigenesis, NCAM1+CD133- marks SIX2+ blastema that includes the ALDH1+ WT cancer stem/initiating cells, while NCAM1+CD133+ and NCAM1-CD133+ specifying early and late epithelial differentiation, are severely restricted in tumor initiation capacity and tumor self-renewal. Thus, negative selection for CD133 is required for defining NCAM1+ nephron stem cells in normal and malignant nephrogenesis. Overall design: Human fetal kidney mRNA profiles of 3 cell populations (NCAM1+/CD133-, NCAM+/CD133+, NCAM-/CD133+) were generated by deep sequencing using Illumina HiSeq.
Dissecting Stages of Human Kidney Development and Tumorigenesis with Surface Markers Affords Simple Prospective Purification of Nephron Stem Cells.
No sample metadata fields
View Samples