Transcription profiling of liver from wild type and glucocorticoid receptor knock out mice after dexamethasone treatment
ABSTRACT: The aim of this study is to identify novel glucocorticoid receptor (GR) regulated hepatic target genes. In order to do so, we used microarray technology to compare the gene expression of wild type and GR-null mice after 3 hrs of dexamethasone treatment.
Project description:Mammalian lung development during the saccular and alveolar stages is dependent upon antagonistic molecular signalling by endogenous retinoic acid (RA) and glucocorticoids (GCs) which regulate gene expression via the retinoic acid receptor (RAR) family and the glucocorticoid receptor (GR), respectively. The genomic mechanism of this antagonism was investigated with in vitro distal lung explant cultures from E18.5 GR-null (GR-/-) mice treated with all-trans-RA (atRA) for 2h . Whole mouse genome microarray analysis from lung explant tissue identified a small number of gene targets which were not only significantly induced by atRA in the wildtype lung, but also significantly stimulated to levels greater than atRA-treated wildtype lungs in GR-/- lungs.
Project description:Myeloid derived Suppressor cells (MDSC) are heterogenous popluation of cells consists of two major subsets namely the monocytic Gr-1dull/int. and granulocytic (Gr-1high). These distinct two subsets use different mechanism to inhibit T cell response. In addition, how the function of these subsets is regulated is not known yet. The Gr-1dull/int. MDSC are suppressing T cells through IFNg dependent nitric oxide dependent manner. However, the exact suppressive mechanism of Gr-1high MDSC is not clear. Here we studied the role of a cytokine IFNg on the suppressive function of Gr-1high MDSC by comparing the gene expression of Gr-1high cells cultured alone versus those cultured with T cells which donot produce IFNgamma. CD11b+Gr-1high cells were purified from the splenocyte of CT-26 colon tumor bearing mice. The purified CD11b+Gr-1high MDSCs were cultured with IFNg-/- antigen specific T cells and re- sorted after 48h and RNA was extracted and gene expression was analyzed using topic-defined PIQORTM Immunology Microarrays.
Project description:Pro35SLBD16:GR or Pro35SLBD18:GR transgenic seedlings that overexpress LBD16 or LBD18 fused to glucocorticoidsteroid hormone binding domain(GR) under CaMV35S promoter were grown for 12 days under long-day conditions (16h light/ 8h dark).
Project description:The use of glucocorticoids (GCs), which bind and activate the glucocorticoid receptor (GR), in systemic inflammatory response syndromes (SIRS) is disputed. Mice with a poor transcriptional response of dimer-dependent GR target genes were studied in a model of TNF-induced SIRS. These GR dim/dim mice display a significant increase in TNF sensitivity and a lack of protection by the GC dexamethasone (DEX). Unchallenged GR dim/dim mice have a strong interferon-stimulated gene (ISG) signature at the transcriptional level and this ISG signature is gut specific. Here, we used shotgun proteomics to study the regulation of ISG proteins in the ileum of GR dim/dim mice. Our data showed that unchallenged GR dim/dim mice have a strong interferon-stimulated gene (ISG) signature, along with STAT1 upregulation. Taken together, we show that GR dim/dim mice poorly control ISG expression resulting in excessive necroptosis induction by TNF. Our findings support a critical interplay between gut microbiota, interferons, necroptosis and GR in both the basal response to acute inflammatory challenges and in the pharmacological intervention by GCs.
Project description:In metabolic control, GC signaling acts as a major counter-regulatory system against insulin action, and aberrantly elevated GC activity is tightly linked to major components of the so-called Metabolic Syndrome, including obesity, insulin resistance, hyperglycemia, and systemic dyslipidemia. Here we identify the hepatic induction of the conserved microRNA (miR)-379/410 genomic cluster as a key component of GC/GR-driven metabolic dysfunction in “diabesity” Microarray data were utilized to screened for differentially regulated miRNAs between wt and db/db and between wt and GR Knockdown mice For wt vs. db/db: mice were fasted for 24 hours and refed for 6 hours; For GR-dependent miRNAs: mice were treated with rAAV delivering either control or GR-directed miRNA for the knockdown of the GR specifically in the liver.
Project description:Differentially expressed genes of CD11b+Gr-1+ immature myeloid cells (IMCs) in the bone marrow and colonic tumor setting of histidine decarboxylase (HDC)-KO mice were examined by microarray (Affymetrix Mouse 430.2 array). Myeloid differentiation-related candidate genes were sought to be isolated and functionally studied. Total RNA of HDC-expressing CD11b+Gr-1+ IMCs of bone marrow were extracted from HDC-EGFP and HDC-EGFP/HDC-KO mice (3 mice in each group). CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) of colon tumor were sorted from 10-12 colon tumors of WT and HDC-KO mice (5 mice in each group), and pooled to extract total RNA for microarray studies. Two technical replicates for each of the four groups. Four sets of comparisons were performed to screen for upregulated or downregulated genes in the HDC-KO CD11b+Gr-1+ IMCs or MDSCs (experiment group) compared to the WT group: (1) HDC-expressing CD11b+Gr-1+ IMCs of bone marrow of HDC KO mice compared to bone marrow IMCs of WT mice; (2) CD11b+Gr-1+ MDSCs in tumors of HDC-KO mice compared to WT mice; (3) CD11b+Gr-1+ MDSCs of WT colon tumors compared to IMCs in the WT bone marrow; and (4) CD11b+Gr-1+ MDSCs of colon tumors of HDC-KO mice compared to IMCs in the bone marrow of HDC-KO mice.
Project description:We used AAV as a vector to deliver hGRβ to the liver of GR Liver Knockout mice. We collected liver samples for microarray analysis to investigate any phenotype as well as the underlying specific signaling pathway. In particular, we would like to determine if and how hGRβ overexpression in liver affects mGRα’s gene transcription profile in GR Liver Knockout mice. GR Liver Knockout mice were treated with PBS, AAV-GFP and AAV-hGRB, respectively. Each treatment group has four replicates.
Project description:We proposed an experiment that determines liver gene regulation profiles in GRLKO. By comparison to the wide type C57BL/6 mouse, we determined the contribution of GR on liver gene expression either at basal level or after Dexamethasone (DEX) injection. WT and GR knockout mice were divided into two groups, one with dexamethasone treatment and one with out. Each group has four replicates.