Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders.
Deregulation of microRNAs by HIV-1 Vpr protein leads to the development of neurocognitive disorders.
Specimen part, Cell line, Treatment
View SamplesRNA polymerase III (Pol III) is an essential enzyme responsible for the synthesis of several small non-coding RNAs, a number of which are involved in mRNA translation. Recessive mutations in POLR3A, encoding the largest subunit of Pol III, cause POLR3-related hypomyelinating leukodystrophy (POLR3-HLD), characterized by deficient central nervous system myelination. Identification of the downstream effectors of pathogenic POLR3A mutations has been so far elusive. Here, we used CRISPR-Cas9 to introduce the POLR3A mutation c.2554A>G (p.M852V) into human cell lines and assessed its impact on Pol III biogenesis, nuclear import, DNA occupancy, transcription, and protein levels. Transcriptomic profiling uncovered a subset of transcripts vulnerable to Pol III hypofunction, including a global reduction in tRNA levels. The brain cytoplasmic BC200 RNA (BCYRN1), involved in translation regulation, was consistently affected in all our cellular models, including patient-derived fibroblasts. Genomic BC200 deletion in an oligodendroglial cell line led to major transcriptomic and proteomic changes, having a larger impact than those of POLR3A mutations. Upon differentiation, mRNA levels of the MBP gene, encoding myelin basic protein, were significantly decreased in POLR3A-mutant cells. Our findings provide the first evidence for impaired Pol III transcription in cellular models of POLR3-HLD and identify several candidate effectors, including BC200 RNA, having a potential role in oligodendrocyte biology and involvement in the disease. Overall design: Gene expression profiling of Pol III transcripts in control and POLR3A-mutated cell lines (HEK293 and MO3.13) using RNA-seq and small RNA-seq; ChIP-seq of FLAG-tagged POLR3A-WT and mutated POLR3A-M852V
Leukodystrophy-associated <i>POLR3A</i> mutations down-regulate the RNA polymerase III transcript and important regulatory RNA <i>BC200</i>.
No sample metadata fields
View SamplesUsing a novel class of chemically-engineered oligonucleotides, termed "antagomirs", we studied the biological significance of silencing miR-122 in the liver of mice at the mRNA level
Silencing of microRNAs in vivo with 'antagomirs'.
No sample metadata fields
View SamplesThis data set was generated by the UK Brain Expression Consortium and consists of gene expression data generated from post-mortem human brain samples, dissected from 10 brain regions and originating from a large cohort of neurologically and neuropathologically normal individuals.
Analysis of gene expression data using a linear mixed model/finite mixture model approach: application to regional differences in the human brain.
Sex, Disease, Subject
View SamplesDevelopment of systems allowing the maintenance of native properties of mesenchymal stromal cells (MSC) is a critical challenge for studying physiological functions of skeletal progenitors, as well as towards cellular therapy and regenerative medicine applications. Conventional stem cell culture in monolayer on plastic dishes (2D) is associated with progressive loss of functionality, likely due to the absence of a biomimetic microenvironment and the selection of adherent populations. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow cells within the pores of 3D scaffolds in a perfusion-based bioreactor system, followed by enzymatic digestion for cell retrieval. The 3D-perfusion system supported MSC growth while maintaining cells of the hematopoietic lineage, and thus generated a cellular environment mimicking some features of the bone marrow stroma. As compared to 2D-expansion, sorted CD45- cells derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7-8 doublings) maintained a 4.3-fold higher clonogenicity and exhibited a superior differentiation capacity towards all typical mesenchymal lineages, with similar immunomodulatory function in vitro. Transcriptomic analysis performed on MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability as well as a significant upregulation of multipotency-related gene clusters following 3D-perfusion as compared to 2D expansion. The described system offers a model to study how factors of a 3D engineered niche may regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems.
Expansion of human mesenchymal stromal cells from fresh bone marrow in a 3D scaffold-based system under direct perfusion.
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View SamplesThe Hippo pathway directs cell differentiation during organogenesis, in part by restricting proliferation. How Hippo signaling maintains a proliferation-differentiation balance in developing tissues and its underlying molecular targets are poorly understood. Our study shows that Hippo suppresses NF?B signaling in pancreatic progenitors to permit cell differentiation and developmental progression. We found that pancreas-specific Lats1/2 kinase deletion (Lats1/2PanKO) from mouse progenitor epithelia results in failure to differentiate 3 key pancreatic lineages: acinar, ductal, and endocrine. We performed an unbiased transcriptome analysis to query the differentiation defects in Lats1/2PanKO. This analysis revealed increased NF?B activator expression, including the pantetheinase Vanin1 (Vnn1). Through in vivo and ex vivo studies, we show that VNN1 activates a detrimental cascade of processes in Lats1/2PanKO epithelium, whereby 1) NF?B activation and 2) initiation of epithelial-to-mesenchymal transition (EMT) together override normal differentiation. We show that exogenous stimulation of VNN1 or NF?B can also trigger this cascade in WT pancreatic progenitors. These findings show that pancreas development requires active suppression of NF?B by LATS1/2 kinases to restrain a cell-autonomous transcriptional program and thereby allow for differentiation. Overall design: RNA-Seq comparing total RNA from 5 WT samples and 3 Lats1/2-deficient pancreas samples at E11.0.
LATS1/2 suppress NFκB and aberrant EMT initiation to permit pancreatic progenitor differentiation.
Cell line, Subject
View SamplesThe transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 8 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated that the suppression of Keap1 expression induced genes that are involved in anti-oxidative stress defense and biotransformation, pathways proving the activation of Nrf2 by the siRNAs against Keap1. The expression of neither fatty acid- nor carbohydrate-handling proteins was regulated by the suppression of Keap1. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance by the activation of Nrf2. The data indicate that hepatic Nrf2 is not a major regulator of intermediary metabolism in mice.
Chronic Activation of Hepatic Nrf2 Has No Major Effect on Fatty Acid and Glucose Metabolism in Adult Mice.
Specimen part, Treatment
View SamplesHow plants determine the final size of growing cells is an important, yet unanswered question. Root hairs provide an excellent model system to study this question since their final cell size is remarkably constant under given environmental conditions. In this study we demonstrate that a trihelix transcription factor GT-2-LIKE1 (GTL1) and its homolog DF1 repress root hair growth in Arabidopsis. Our transcriptional data, combined with genome-wide chromatin binding data, show that GTL1 and DF1 directly bind the RSL4 promoter and regulate its expression to repress root hair growth. Our data further show that GTL1 and RSL4 regulate each other as well as a set of common downstream genes, many of which have previously been implicated in root hair growth. This study therefore uncovers a core regulatory module that fine-tunes the extent of root hair growth by orchestrated actions of opposing transcription factors.
GTL1 and DF1 regulate root hair growth through transcriptional repression of <i>ROOT HAIR DEFECTIVE 6-LIKE 4</i> in <i>Arabidopsis</i>.
No sample metadata fields
View SamplesWe report the differential gene expression differences between control and Ovol2-deficent newborn keratinocytes Overall design: Two control and two Ovol2-deficent samples were isolated
An Ovol2-Zeb1 transcriptional circuit regulates epithelial directional migration and proliferation.
Specimen part, Subject
View SamplesIntroduction: Sepsis is a complex immunological response to infection characterized by early hyperinflammation followed by severe and protracted immunosuppression, suggesting that a multi-marker approach has the greatest clinical utility for early detection, within a clinical environment focused on SIRS differentiation. Pre-clinical research using an equine sepsis model identified a panel of gene expression biomarkers that define the early aberrant immune activation. Thus, the primary objective was to apply these gene expression biomarkers to distinguish patients with sepsis from those who had undergone major open surgery and had clinical outcomes consistent with systemic inflammation due to physical trauma and wound healing.
Development and validation of a novel molecular biomarker diagnostic test for the early detection of sepsis.
Specimen part
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