Project description:Vasopressin is the major hormone that regulates renal water excretion. It does so by binding to a receptor in renal collecting duct cells, triggering signaling pathways that ultimately regulate the abundance, location, and activity of the water channel protein aquaporin 2. We took an advantage of quantitative large scale proteomic technologies and oligonucleotide microarrays to quantify steady state changes in protein and transcript abundances in response to vasopressin in a collecting duct cell line, mpkCCD clone 11 (Yu et al. PNAS 2009, 106:2441-2446). This cell line originally developed by Alan Vandewalle’s group recapitulates vasopressin-mediated AQP2 expression and phosphorylation as seen in native colleting duct cells. The mpkCCD cells were grown on membrane supports to permit polarization. Once transepithelial resistance reached 5kohm per centimeter square and higher, the cells were exposed to the vasopressin V2 receptor analog, dDAVP, at a physiological concentration, 0.1nM, for 5 days. Control experiments were done with cells exposed to vehicle alone. Total RNA was harvested and processed for transcript expression analysis using Affymetrix GeneChip Mouse Genome 430 2.0 Arrays. Each experimental treatment, vehicle and dDAVP, was repeated 3 times.
Project description:Purpose: The goal of this study is to identify vasopressin-regulated genes in mouse kidney collecting duct cell line mpkCCD. To explore dynamic regulation of vasoressin-mediated transcriptional regulation, transcriptome of vasopressin-treated cells at four different time points (3h, 6h, 12h, and 24h) were profiled and analyzed. Methods: Total RNAs were isolated from vasopressin-treated mpkCCD cells at different time points (3h, 6h, 12h, and 24h). Three replicates for vehicle- or vasopressin-treated group were generated at each tested time point. cDNA libraries were prepared using a Nextera DNA library preparation protocol. The sequence reads from Illumina HiSeq3000 platform were qualified and quantified at the transcript level using Salmon (0.14.1). Differential expression analysis were performed using edgeR. Results: mRNA profiles of mouse kidney collecting duct mpkCCD cells treated with vasopressin analog (dDAVP) for four different time potins (3h, 6h, 12h, and 24h) were generated using an optimized RNA-Seq workflow. Transcript level quantification using a pseudo-alignment quantification method (Salmon) was performed to calculate transcript abundance in each sample. Then differential expression analysis identified the differentially expressed genes including Aqp2 gene at each time point comparison (dDAVP vs vehicle, FDR < 0.05). In addition, several new vasopressin-responsive genes that have not been elucidated before were identified. Conclusions: This study revealed dynamic changes of vasopressin-responsive gene expression within 24 hours in mouse kidney collecting duct cells. The results from time-course transcriptome profiling identified the known vasopressin-responsive genes and several novel gene that are regulated temporally.
Project description:The Ca2+/CaM-dependent protein kinase 2-delta (CAMK2D) has been proposed to be involved in vasopressin signaling in the renal collecting duct, which controls water and salt excretion by the kidney. RNA sequancing and quantitative proteomics analyses identified the expression of multiple CAMK2 isoforms, with CAMK2D being the most abundant in collecting duct cells. To investigate the role of CAMK2D in regulating RNA expression in response to vasopressin signaling, the transcriptome of CRISPR/Cas9-mediated Camk2d knock-out mpkCCD cells was profiled using RNA-Seq in the presence of vasopressin analogue dDAVP.
Project description:We sequenced mRNAs and mapping the binding of RNA polymerase 2 in collecting duct cells treat with Vasopressin or vehicle. Confluent mpkCCD cell monolayers were maintained in serum-free medium for 24 h prior to treatment with or without 0.1 nM dDAVP in serum-free medium for 24 h. followed RNA polymerase 2 Chip seq.
Project description:Vasopressin, a peptide hormone, controls renal water excretion, largely through regulation of water channel aquaporin-2 (AQP2) in the renal collecting duct. There are two regulatory mechanisms of AQP2: 1) short-term regulation by membrane trafficking of AQP2; and 2) long-term regulation involving vasopressin-induced changes of protein abundance of AQP2 through regulation of gene transcription and protein half-life. Vasopressin binds a G protein-coupled receptor (V2R) activating several downstream signaling pathways. At downstream of V2R activation, many of transcription factors involve gene transcription process associated with status of chromatin structure. ATAC-Seq (Assay for Transpoase-Accessible Chromatin using Sequencing) is a recent technique to study chromatin accessibility (Buenrostro et al. Nat Methods 2013). We carried out ATAC-Seq following standard an ATAC-Seq protocol in mpkCCD cells treated with vehicle or dDAVP for 30 minutes.
Project description:This is a 2-plex SILAC-based quantitative proteomic study. It quantifies abundance changes of the apical membrane proteins of the kidney collecting duct model cells (mpkCCD) in response to vasopressin. Cells were labeled with normal or heavy lysine and arginine and then exposed to vehicle or the vasopressin analogy dDAVP (1 nM, 1 hour). Apical membrane proteins of vehicle and dDAVP-treated cells were enriched via surface biotinylation and affinity purification prior to LC-MS/MS analysis. Database search and protein quantification were performed using the SEQUEST algorithm included in the Proteome Discover Version 1.3 (Thermo Scientific). The database used for the spectral searching was prepared from the mouse RefSeq database plus common contaminants.
Project description:Water homeostasis is regulated by the peptide hormone arginine vasopressin (AVP), which promotes water reabsorption in the renal collecting duct. The regulation of Aqp2 gene transcription is a key mechanism through which AVP modulates water transport as disruption of this mechanism leads to water balance disorders. Therefore, an important goal is to understand the regulatory processes that control Aqp2 gene transcription. While CREB (CREB1) has been proposed as the primary transcription factor responsible for Aqp2 transcription, recent evidence challenges this view, suggesting that other CREB-like transcription factors, including ATF1 and CREM, may play a role. We employed the CRISPR/Cas9 gene-editing system to delete Atf1, Creb1, and Crem in mpkCCD cells, an immortalized collecting duct cell line. These cell lines were then exposed to the vasopressin analog dDAVP to assess the role of these transcription factors in regulating Aqp2 expression. Deletion of all three transcription factors (ATF1, CREB1, and CREM) led to a significant reduction in the vasopressin-induced upregulation of AQP2 protein, confirming their role in regulating Aqp2 expression. Rescue experiments in triple knockout cells showed that expressing any of the three transcription factors restored the response to vasopressin. RNA-seq data showed that Aqp2 mRNA levels mirrored changes in protein abundance, supporting the idea that these transcription factors affect Aqp2 transcription. Our findings demonstrate that ATF1, CREB1, and CREM have redundant roles in regulating Aqp2 transcription. Our results suggest that these transcription factors might regulate the expression of other unidentified transcription factors involved in Aqp2 regulation.
Project description:Vasopressin, a peptide hormone, controls renal water excretion, largely through regulation of water channel aquaporin-2 (AQP2) in the renal collecting duct. There are two regulatory mechanisms of AQP2: 1) short-term regulation by membrane trafficking of AQP2; and 2) long-term regulation involving vasopressin-induced changes of protein abundance of AQP2 through regulation of gene transcription and protein half-life. Vasopressin binds a G protein-coupled receptor (V2R) activating a cyclic AMP/protein kinase A (PKA) signaling pathway. Sequentially, after activation of cAMP/PKA signaling, many of transcription factors involve gene transcription process. cAMP-response element binding protein (CREB) and cAMP-responsive transcription factor C/EBP beta are potential candidates for vaopressin-mediated regulation of Aqp2 gene transcription proviously reported. In the present study, genome-wide binding sites for two b-ZIP transcription factors CREB and C/EBP beta were identified in vasopressin-responsive mouse collecting duct mpkCCD cells using ChIP-Seq.
Project description:Vasopressin is the major hormone that regulates renal water excretion. It does so by binding to a receptor in renal collecting duct cells, triggering signaling pathways that ultimately regulate the abundance, location, and activity of the water channel protein aquaporin 2. We took an advantage of quantitative large scale proteomic technologies and oligonucleotide microarrays to quantify steady state changes in protein and transcript abundances in response to vasopressin in a collecting duct cell line, mpkCCD clone 11 (Yu et al. PNAS 2009, 106:2441-2446). This cell line originally developed by Alan Vandewalle’s group recapitulates vasopressin-mediated AQP2 expression and phosphorylation as seen in native colleting duct cells.
Project description:Vasopressin, the antidiuretic hormone, acts on the renal collecting duct. In this experiment both vasopressin (AVP) and the V2R specific agonist dDAVP were infused into Aquaporin 1 knockout animals for 7 days. The aim of the experiment was to identify genes increased by vasopressin receptors in the renal medullary collecting ducts, in the absence of an increase in renal medullary osmolarity (the AQP1 knockouts are concentrating mechanism knockouts). All experiments used inner medulla tissue for the RNA isolation. Hybridizations were performed that compared kidney inner medulla total RNA from three control mice against kidney medulla total RNA from 3 mice infused with either arginine vasopressin (AVP) or des-amino-D-arginine vasopressin (dDAVP).