RNA-seq of the whole retina of rat intravitreally injected with aldosterone
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ABSTRACT: The mineralocorticoid receptor is expressed in the rat and human retina. We previously showed that intravitreal injection of aldosterone in rat eyes induced retinal œdème and choroidal vasodilation and permeability through regulation of ion/water channels (Zhao et al. Faseb J, 2009; Zhao et al. J Clin Invest 2012). Illicit activation of MR induces inflammation, oxidative stress and tissue remodeling in cardiovascular and renal diseases independent of hypertension. We performed a full transcriptomic study destinated to identify genes regulated by aldosterone in the whole retina of rat.
Project description:Effects of aldosterone on the transcriptome in distal colon. Expression of genes was studied in distal colon surface cells from aldosterone treated vs. vehicle treated rats.
Project description:The mineralocorticoid hormone aldosterone controls sodium reabsorption and blood pressure largely by regulating the cell-surface expression and function of the epithelial sodium channel ENaC in target kidney tubules. Part of the stimulatory effect of aldosterone on ENaC is mediated by the induction of SGK1, a kinase that interferes with the ubiquitylation of ENaC by ubiquitin-protein ligase Nedd4-2. We performed a microarray study in order to investigate which other gene products are rapidly regulated by aldosterone in target cells that participate to the control of Na+ reabsorption and K+ secretion.
Project description:Murine inner medullary collecting duct cells were treated for 1 hour with vehicle (control) or aldosterone. Total RNA was isolated and used as template to generate the eventual cRNA target. The experiment was repeated a total of three times. Six cRNA samples, three control and three treated, were generated and used in a total of six hybridizations. The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney.
Project description:The “aldosterone paradox” is a poorly understood physiological mechanism in which increases in the hormone aldosterone either serve to stabilize blood pressure by increasing sodium-chloride (NaCl) reabsorption or to excrete potassium (K+). Under low NaCl intake, abundance and activity of the thiazide-sensitive NaCl cotransporter NCC, expressed in the distal convoluted tubule (DCT), is high, whereas it is low during high K+ intake - leading to increased delivery of NaCl to downstream segments and increased electrogenic K+ secretion. Despite a critical role in blood pressure and K+ homeostasis, little is known about the molecular alterations in the DCT during the aldosterone paradox, and how they control NCC levels. The objective of this study was to define the proteome of the DCT and how it is modified by increased circulating aldosterone levels subsequent to long-term low dietary NaCl or high K+ intake.
Project description:Target gene of mineralocorticoid receptor (MR) is comparatively unknown, although distal convoluted tubule (DCT) expresses MR in in vivo. We used microarray and immortalized murine DCT cell-line overexpressing human MR with treatment of aldosterone to elucidate target genes of MR in DCT. mDCT overexpresses human MR by lipofection and is treated for 3 hours with ethanol (g1), or 10^-9 M aldosterone (g2), or 10^-7 M aldosterone (g3), or 10^-7 M aldosterone with pretreatment of 5 x 10^-6 M spironolactone (g4) for 2 hours.
Project description:The affect of aldosterone on the miRNA landscape in mIMCD-3 cells was determined In the study presented here, the affect of aldosterone was examined on the miRNA content in a murine inner medullary collecting duct cell line
Project description:Aldosterone, the main mineralocorticoid hormone in Humans, has a major role in maintaining the hemo-electrolytique homeostasis, by acting in the distal part of nephron. This steroid hormone mainly acts through its binding to a ligand-induced transcription factor, the mineralocorticoid receptor (MR). MR binds to specific genomic sequences, where it recruits transcriptional coregulators, to activate or repress target gene transcription. The aim of this work was to access the whole aldosterone-dependand MR target genes, by comparing sequenced data from aldosterone or vehicle-treated samples. Anti-MR ChIP-seq in Human Kidney GFP-hMR cells treated with vehicle or Aldosterone.
Project description:Analysis of aldosterone-producing adenoma (APA) samples from patients with primary hyperaldosteronism. These APAs have a somatic mutation in either KCNJ5, CACNA1D, or ATP1A1. Results provide insight into the different mechanisms each mutation may cause leading to elevated aldosterone production in APA. In this dataset, we include expression data from aldosterone-producing adenomas (APAs) with a somatic mutation in either KCNJ5, CACNA1D, or ATP1A1. These data are used to obtain differentially expressed genes between KCNJ5 mutant APAs and CACNA1D/ATP1A1 mutant APAs. A total of 13 samples were analyzed (8 KCNJ5 mutant APAs and 5 CACNA1D/ATP1A1 mutant APAs). 43 genes had a false discovery rate (FDR) <0.5% and were >2-fold different between KCNJ5 mutant APAs and 5 CACNA1D/ATP1A1 mutant APAs. The two sets of genotypes were separated on unsupervised hierarchical clustering of 1475 genes correlating >0.6 with CYP11B2.
Project description:Kidney distal convoluted tubules (DCT) are important for regulation of urinary salt excretion. Aldosterone is known to exert long-term effects in this segment, and regulate sodium reabsorption via increasing abundance of the Na+-Cl- cotransporter (NCC) and the epithelial Na channel ENaC. Whether acute effects of aldosterone occur in the DCT and the potential signaling networks remain unknown. Here in this study, we aim to identify the acute aldosterone-mediated signaling (rapid effects) in the DCT.