Project description:Primary aldosteronism (PA) is the most frequent form of secondary arterial hypertension. Mutations in different genes increase aldosterone production in PA, but additional mechanisms may contribute to increased cell proliferation and aldosterone producing adenoma (APA) development. We performed transcriptome analysis in APA and identified retinoic acid receptor alpha (RARα) signaling as a central molecular network involved in nodule formation. To understand how RARα modulates adrenal structure and function, we explored the adrenal phenotype of male and female Rarα knockout mice. Inactivation of Rarα in mice led to major structural disorganization of the adrenal cortex in both sexes, with increased adrenal cortex size in female mice and increased cell proliferation in males. Abnormalities of vessel architecture and extracellular matrix were due to decreased Vegfa expression and modifications in extracellular matrix components. On the molecular level, Rarα inactivation leads to inhibition of non-canonical Wnt signaling, without affecting the canonical Wnt pathway nor PKA signaling. Our study suggests that Rarα contributes to the maintenance of normal adrenal cortex structure and cell proliferation, by modulating Wnt signaling. Dysregulation of this interaction may contribute to abnormal cell proliferation, creating a propitious environment for the emergence of specific driver mutations in PA.
Project description:Comparison between ChIP-Seq data of RAR? and RAR?, between RAR and RXR, as well as between control and retinoic acid-treatment for each investigated nuclear receptors. Mouse were treated by control diet and RA-diet for 1 days. After treatment, livers were used to do ChIP using antibodies of RXR?, RAR?, and RAR?. An aliquote of total chromatin without pull-down process by any antibodies was used as input control. A single-end read of 35bp sequencing was performed on each of ChIPed DNA and input. Sequencing data of RAR? and RAR? were compared to each other. In addtional, each of RAR? and RAR? data were compared with RXR? data. For each nuclear receptor, ChIP-Seq data prior or after RA-treatment were also compared with each other.
Project description:This study investigates the effects of the aryl hydrocarbon receptor (AhR) ligands TCDD and PCB126 on hepatic gene expression in female sprague dawley rats. Rats were treated with toxicological equivalent doses of TCDD (100ng/kg/day) (Toxic equivalence factor (TEF) = 1.0), PCB126 (30ng, 300ng or 1000ng/kg/day) (TEF = 0.1) or a vehicle control of corn oil:acetone (99:1) 5 days a week for 52 weeks.
Project description:A study of rat femoral fracture healing in young (6 weeks old at fracture), adult (26 weeks old at fracture), and old (52 weeks old at fracture) rats. Samples were collected at time of surgery (intact controls) and at 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after fracture. Samples were the mid third of the femoral length including the external callus, cortical bone and marrow elements. Fracture was stabilized with an intramedullary rod prior to fracture with a Bonnarens and Einhorn device.
Project description:We asked whether there were any expression changes in liver genes associated with loss of betaine homocysteine methyltransferase (BHMT) function and how do they relate across time, at 4 and 52 weeks. We computed the robust multichip average (RMA) normalized expression of 34,472 genes available for analysis.
Project description:Retinoic Acid Receptors (RARs) as a functional heterodimer with Retinoid X Receptors (RXRs), bind a diverse series of RA-response elements (RAREs) in regulated genes. Among them, the non-canonical DR0 elements are bound by RXR-RAR with comparable affinities to DR5 elements but DR0 elements do not act transcriptionally as independent RAREs. In this work, we present structural insight for the recognition of DR5 and DR0 elements by RXR-RAR heterodimer using x-ray crystallography, small angle x-ray scattering, and hydrogen/deuterium exchange coupled to mass spectrometry. We solved the crystal structure of RXR-RAR DNA-binding domain in complex with the Rarb2 DR5 and RXR DNA-binding domain in complex with Hoxb13 DR0. While cooperative binding was observed on DR5, on DR0 the two molecules bound non-cooperatively on opposite sides of the DNA. In addition, our data unveil the structural organization and dynamics of the multi-domain RXR-RAR DNA complexes providing evidence for DNA-dependent allosteric communication between domains. Differential binding mode between DR0 and DR5 were observed leading to differences in the conformation and structural dynamics of the multi-domain RXR-RAR DNA complex. These results reveal that the topological organization of the RAR binding element confer regulatory information by modulating the overall topology and structural dynamics of the RXR-RAR heterodimers.
Project description:This study investigates the effects of the aryl hydrocarbon receptor (AhR) ligands TCDD and PCB126 on hepatic gene expression in female sprague dawley rats. Rats were treated with toxicological equivalent doses of TCDD (100ng/kg/day) (Toxic equivalence factor (TEF) = 1.0), PCB126 (30ng, 300ng or 1000ng/kg/day) (TEF = 0.1) or a vehicle control of corn oil:acetone (99:1) 5 days a week for 52 weeks. There are 3 control chips and representing animals treated with vehicle control. There are 3 biological replicates (3 chips) for each treatment group (eg. TCDD, PCB126), each biological replicate is derived from 2 individual animals. A total of 15 chips were analyzed.
Project description:Percellome analysis of whole Xenopus embryos at developmental stage 18 Xenopus embryos were treated with TTNPB (RAR-agonist), AGN193109 (RAR-antagonist), or Control Vehicle at Nieuwkoop and Faber Stage 7. Embryos were collected at stage 18, followed by RNA extraction, hybridization on Affymetrix microarrays, and Percellome analysis.
Project description:The lack of a preclinical model of nonalcoholic steatohepatitis (NASH) and hepatocellular cancer (HCC) that recapitulates human disease is a major barrier to therapeutic development. We report a high fat-high sugar diet-induced NASH and HCC in a stable isogenic 129S1/SvImJ crossed with C57Bl/6J mice. Following diet initiation, there was sequential development of steatosis (4-8 weeks), steatohepatitis with ballooning and Mallory-Denk bodies (12-16 weeks), progressive fibrosis (16 week onwards) and spontaneous HCC (32-52 weeks). The mice developed obesity, insulin resistance and dyslipidemia. There was concordance with the human NASH transcriptome (FDR 0.001) with activation of lipogenic, inflammatory and apoptotic pathways relevant in humans. The HCC gene signature resembled S1 and S2 human HCC subclass (FDR 0.01 for both). This simple model of NASH and HCC that resembles human disease in terms of its triggers, physiological and biochemical parameters, histology, transcriptomic profile, and outcomes can facilitate preclinical development for these conditions. 129S1/SvImJ;C57Bl/6J (129/B6) mice were fed with high-fat diet (Western Diet) and high fructose-glucose solution (Sugar Water) (WD SW) or chow diet (CD) for 52 weeks, and total RNA samples were isolated from liver and tumor tissues for genome-wide expression profiling.