Heterogeneous nuclear ribonucleoprotein (hnRNP) C1/C2 plays a pivotal role in vitamin D receptor (VDR) signaling by acting as a vitamin D response element (VDRE)-binding protein (VDRE-BP). Transcriptional regulation by active 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) involves occupancy of VDRE by VDRE-BP or 1,25(OH)2D3 bound-VDR. This relationship is disrupted by over-expression of VDRE-BP and can cause a form of human hereditary vitamin D-resistant rickets (HVDRR). DNA array analyses using B-cells from an HVDRR patient and matched control defined a sub-cluster of genes where 1,25(OH)2D3-regulated transcription was abrogated by over-expression of VDRE-BP. Amongst these, the DNA-damage-inducible transcript 4 (DDIT4), an inhibitor of mammalian target of rapamycin (mTOR) signaling, was also induced by 1,25(OH)2D3 in human osteoblasts.
Gene targeting by the vitamin D response element binding protein reveals a role for vitamin D in osteoblast mTOR signaling.
Sex, Specimen part, Subject
View SamplesHeterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC1/C2) functions as an RNA splicing regulator through co-transcriptional association with nascent mRNA. HnRNPC1/C2 can also bind to double-stranded DNA as a vitamin D response element-binding protein (VDRE-BP), thereby regulating transcriptional activity of the vitamin D receptor (VDR) bound to 1,25-dihydroxyvitamin D (1,25(OH)2D). In this way hnRNPC1/C2 may act as a coupling factor for 1,25(OH)2D-directed transcription and RNA splicing. Studies using MG63 osteoblastic cells confirmed that 1,25(OH)2D-VDR mediated induction of the gene for the enzyme 24-hydroxylase (CYP24A1), involved CYP24A1-specific chromatin and RNA immunoprecipitation of hnRNPC1/C2. Furthermore, small interfering (siRNA) knockdown of hnRNPC1/C2 in MG63 cells and was associated with dysregulated expression of CYP24A1 and an alternatively spliced form of CYP24A1 (CYP24A1-variant 2). Genome-wide analysis of RNA expression and alternative splicing indicated that dual role of hnRNPC1/C2 in directing 1,25(OH)2D-mediated gene expression is not restricted to the classical VDR-target CYP24A1. Knockdown of hnRNPC1/C2 resulted in 3500 differentially expressed genes (DEG), and treatment with 1,25(OH)2D 324 DEG. A further 87 DEG were only observed in 1,25(OH)2D-treated cells in hnRNPC1/C2 knockdown cells. HnRNPC1/C2 knockdown or 1,25(OH)2D treatment also induced alternative splicing (AS) (5039 and 310 AS events respectively). Combined hnRNPC1/C2 knockdown and 1,25(OH)2D treatment resulted in significant overlap between DEG and AS genes, but this was not observed for 1,25(OH)2D treatment alone. These data indicate that hnRNPC1/C2 can act to couple transcriptional and splicing responses to 1,25(OH)2D by binding to both DNA and RNA. Similar mechanisms may also exist for other members of the hnRNP and steroid receptor family. Overall design: Human MG63 osteosarcoma cells (American Type Culture Collection, CRL-1427) were cultured in Dulbecco’s modified Eagle medium (DMEM, high glucose, Gibco, 11995-065) supplemented with 10% Fetal Bovine Serum (FBS) cultured at 37oC with 5% CO2. Crystalline 1,25-dihydroxyvitamin D3 (1,25(OH)2D3, Enzo Life Sciences, BML-DM200-0050) was reconstituted in ethanol. Ethanol (0.1%) was used as vehicle treatment. RNA-seq analysis was carried out using total RNA extracted from MG63 cells using RNAeasy mini kit (Qiagen, 74104), with on-column DNase treatment to remove contaminating genomic DNA. cDNA libraries were prepared using the Illumina TruSeq RNA Sample Preparation Kit (illumina). High-throughput sequencing was performed using an Illumina HiSeq2500 (paired-end, non-strand-specific 107-bp read length). Knockdown and control samples were sequenced together in two flowcells on four lanes.
Concerted effects of heterogeneous nuclear ribonucleoprotein C1/C2 to control vitamin D-directed gene transcription and RNA splicing in human bone cells.
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View SamplesTuberculosis remains a major cause of death from an infectious disease worldwide, yet only 10% of people infected with Mycobacterium tuberculosis develop disease. Defining both necessary and sufficient immunologic determinants of protection remains a great scientific challenge. Analysis of peripheral blood gene expression profiles of active tuberculosis patients has identified correlates of risk for disease or pathogenesis. We sought to identify human potential candidate markers of host defense by studying gene expression profiles of macrophages, cells which, upon infection by M. tuberculosis, can mount an antimicrobial response. Weighted gene co-expression network analysis revealed an association between the cytokine, IL-32, and the vitamin D antimicrobial pathway in a network of IFN- and IL-15 induced defense response genes. IL-32 was sufficient for induction of the vitamin D-dependent antimicrobial peptides, cathelicidin and DEFB4, and generation of antimicrobial activity in vitro, dependent on the presence of adequate 25-hydroxyvitamin D. The IL-15 induced defense response macrophage gene network was integrated with ranked pairwise comparisons of gene expression from five different clinical data sets of latent vs. active tuberculosis or healthy controls, and a co-expression network derived from gene expression in patients with tuberculosis undergoing chemotherapy. Together, these analyses identified eight common genes, including IL-32, as molecular markers of latent tuberculosis and the IL-15 induced gene network. Inferring that maintaining M. tuberculosis in a latent state and preventing transition to active disease represents host resistance, we believe these results identify IL-32 as one functional marker and potential correlate of protection against active tuberculosis.
IL-32 is a molecular marker of a host defense network in human tuberculosis.
Specimen part, Subject
View SamplesEffective innate immunity against many microbial pathogens requires macrophage programs that upregulate phagocytosis and direct antimicrobial pathways, two functions generally assumed to be coordinately regulated. Here the regulation of these key functions was investigated in human blood-derived macrophages. IL-10 induced the phagocytic pathway, including CD209 and scavenger receptors, resulting in phagocytosis of mycobacteria and oxLDL. IL-15 induced the vitamin D-dependent antimicrobial pathway and CD209, yet the cells were less phagocytic. The differential regulation of macrophage functional programs was confirmed by analysis of the spectrum of leprosy lesions: the macrophage phagocytosis pathway was prominent in the clinically progressive, multibacillary form, whereas the vitamin D-dependent antimicrobial pathway predominated in the self-limited form of the disease and in patients undergoing reversal reactions from the multibacillary to the self-limited form. These data indicate that macrophage programs for phagocytosis and antimicrobial responses are distinct and differentially regulated in innate immunity in bacterial infections.
Divergence of macrophage phagocytic and antimicrobial programs in leprosy.
Specimen part
View SamplesIn innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.
Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response.
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View SamplesThe immune mechanisms that control resistance vs. susceptibility to mycobacterial infection in humans were investigated by studying leprosy skin lesions, the site where the battle between the host and the pathogen is joined. Using an integrative genomics approach, we found an inverse correlation between of IFN-beta and IFN-gamma gene expression programs at the site of disease. The Type II IFN, IFN-gamma and its downstream vitamin D-dependent antimicrobial genes were preferentially expressed in the lesions from patients with the self-healing tuberculoid form of the disease and mediated antimicrobial activity against the pathogen, Mycobacterium leprae in vitro. In contrast, the Type I IFN, IFN-beta and its downstream genes, including IL-27 and IL-10, were induced in monocytes by M. leprae in vitro, and were preferentially expressed in the lesions of disseminated and progressive lepromatous form. The IFN-gamma induced macrophage antimicrobial response was inhibited by IFN-beta/IL-10, by a mechanism involving blocking the generation of bioactive 1,25-dihyroxy vitamin D as well as inhibiting induction of antimicrobial peptides cathelicidin and DEFB4. The ability of IFN-B to inhibit the IFN-gamma induced vitamin D pathway including antimicrobial activity was reversed by neutralization of IL-10, suggesting a possible target for therapeutic intervention. Finally, a common IFN-beta and IL-10 gene signature was identified in both the skin lesions of leprosy patients and in the peripheral blood of active tuberculosis patients. Together these data suggest that the ability of IFN-beta to downregulate protective IFN-gamma responses provides one general mechanism by which some bacterial pathogens of humans evade protective host responses and contribute to pathogenesis.
Type I interferon suppresses type II interferon-triggered human anti-mycobacterial responses.
Specimen part, Subject
View SamplesNeuregulin (NRG) signaling through the receptor tyrosine kinase, ERBB3, is required for embryonic development, and dysregulated signaling has been associated with cancer progression. Here, we show that NRG1/ERBB3 signaling inhibits melanocyte (MC) maturation and promotes undifferentiated, migratory and proliferative cellular characteristics. Embryonic analyses demonstrated that initial MC specification and distribution were not dependent on ERBB3 signaling. However NRG1/ERBB3 signaling was both necessary and sufficient to inhibit differentiation of later stages of MC development in culture. Analysis of tissue arrays of human melanoma samples suggests that ERBB3 signaling may also contribute to metastatic progression of melanoma as ERBB3 was phosphorylated in primary tumors compared with nevi or metastatic lesions. Neuregulin 1-treated MCs demonstrated increased proliferation and invasion and altered morphology concomitant with decreased levels of differentiation genes, increased levels of proliferation genes and altered levels of melanoma progression and metastases genes. ERBB3 activation in primary melanomas suggests that NRG1/ERBB3 signaling may contribute to the progression of melanoma from benign nevi to malignancies. We propose that targeting ERBB3 activation and downstream genes identified in this study may provide novel therapeutic interventions for malignant melanoma.
NRG1 / ERBB3 signaling in melanocyte development and melanoma: inhibition of differentiation and promotion of proliferation.
Specimen part
View SamplesWe used parkin –overexpressing MRC5 fibroblasts to investigate the role of mitochondria deficiency on senescence-associated gene expression. Overall design: RNA-seq analysis on proliferating and senescent Parkin-expressing MRC5 fibroblasts treated with CCCP (treated) or DMSO (Untreated).
Mitochondria are required for pro-ageing features of the senescent phenotype.
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View SamplesThe aim of reprotoxicity testing is to reveal adverse effects of chemicals and drugs on reproduction and on pre and postnatal fetal development. There is very limited data available on gene expression profiling for elucidation of the teratogenic effects of nongenotoxic teratogens. Therefore, research was undertaken to obtain knowledge on the molecular effects of MSC1096199 (previously known as EMD 82571), a calcium sensitizer that was abandoned in the preclinical development phase due to its teratogenic effects in some foetuses. Pregnant wistar rats were dose daily with either MSC1096199 (50 or 150 mg/kg) or Retinoic acid (12 mg/kg) on gestational days 6-17. Microarray experiment were performed using four different tissues (maternal liver, embryo liver (GD20), embryo bone (GD20), and whole embryo (GD12)) under four different conditions (vehicle, low dose and high dose of MSC1096199 and Retinoic acid) to determine the drug regulated genes. In the high dose treatment group, approximately 58% of the fetuses showed malformations i.e. exencephaly and agnathia, and toxicogenomics evidenced that the genes critically involved in osteogenesis, odontogenesis and extra cellular matrix components to be significantly regulated by MSC1096199, therefore providing a molecular rational for the observed teratogenic effects.
A rat toxicogenomics study with the calcium sensitizer EMD82571 reveals a pleiotropic cause of teratogenicity.
Specimen part, Treatment
View SamplesWe propose comparing liver gene expression of WT and female ERKO mice early in the high-fat feeding period to animals fed a regular chow diet. Analyzing liver tissue before the fatty liver disease phenotype becomes severe will allow identification of target genes which may be causal.
Hormone signaling and fatty liver in females: analysis of estrogen receptor α mutant mice.
Sex, Specimen part
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