scholarly journals Pax2 and Pax8 Proteins Regulate Urea Transporters and Aquaporins to Control Urine Concentration in the Adult Kidney

2020 ◽  
Vol 31 (6) ◽  
pp. 1212-1225 ◽  
Author(s):  
Ann M. Laszczyk ◽  
Atsuko Y. Higashi ◽  
Sanjeevkumar R. Patel ◽  
Craig N. Johnson ◽  
Abdul Soofi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Target Genes ◽  
Collecting Duct ◽  
Expression Patterns ◽  
Renal Medulla ◽  
Urine Concentration ◽  
Renal Epithelia ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Collecting Tubules

BackgroundAs the glomerular filtrate passes through the nephron and into the renal medulla, electrolytes, water, and urea are reabsorbed through the concerted actions of solute carrier channels and aquaporins at various positions along the nephron and in the outer and inner medulla. Proliferating stem cells expressing the nuclear transcription factor Pax2 give rise to renal epithelial cells. Pax2 expression ends once the epithelial cells differentiate into mature proximal and distal tubules, whereas expression of the related Pax8 protein continues. The collecting tubules and renal medulla are derived from Pax2-positive ureteric bud epithelia that continue to express Pax2 and Pax8 in adult kidneys. Despite the crucial role of Pax2 in renal development, functions for Pax2 or Pax8 in adult renal epithelia have not been established.MethodsTo examine the roles of Pax2 and Pax8 in the adult mouse kidney, we deleted either Pax2, Pax8, or both genes in adult mice and examined the resulting phenotypes and changes in gene expression patterns. We also explored the mechanism of Pax8-mediated activation of potential target genes in inner medullary collecting duct cells.ResultsMice with induced deletions of both Pax2 and Pax8 exhibit severe polyuria that can be attributed to significant changes in the expression of solute carriers, such as the urea transporters encoded by Slc14a2, as well as aquaporins within the inner and outer medulla. Furthermore, Pax8 expression is induced by high-salt levels in collecting duct cells and activates the Slc14a2 gene by recruiting a histone methyltransferase complex to the promoter.ConclusionsThese data reveal novel functions for Pax proteins in adult renal epithelia that are essential for retaining water and concentrating urine.

Expression of mRNA for natriuretic peptide receptor subtypes in bovine kidney

1994 ◽  
Vol 267 (2) ◽  
pp. F318-F324 ◽  
Author(s):  
T. Yamamoto ◽  
L. Feng ◽  
T. Mizuno ◽  
S. Hirose ◽  
K. Kawasaki ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Natriuretic Peptide ◽  
Collecting Duct ◽  
Biologically Active ◽  
Ribonuclease Protection Assay ◽  
Receptor Subtypes ◽  
Total Rna ◽  
Duct Cells ◽  
Glomerular Epithelial Cells ◽  
Collecting Duct Cells

The localization of mRNA for atrial natriuretic peptide (ANP) receptor subtypes (A, B, C) in the kidney was examined. Quantitative analysis of the ribonuclease protection assay showed that the numbers of type A receptor (ANPRA) mRNA were 6.9 x 10(7) in the glomeruli and 10.4 x 10(7) molecules/micrograms of total RNA in the inner medulla, and that of type C receptor (ANPRC) mRNA was 21.7 x 10(7) molecules/micrograms of total RNA in the glomeruli. The type B receptor (ANPRB) mRNA was present in smaller numbers (4.5-4.9 x 10(6) molecules/micrograms of total RNA) evenly throughout the kidney fractions. In situ hybridization demonstrated both ANPRA and ANPRC mRNA selectively in the glomerular epithelial cells and ANPRA mRNA in the collecting duct cells of the inner medulla. ANPRC was also localized on the foot processes of glomerular epithelial cells by immunohistochemistry using a specific antibody against the receptor. These results indicate that ANPRA is the major biologically active receptor for the ANP family of hormones in the kidney and is present selectively on the glomerular epithelial cells and inner medullary collecting duct cells. These cells are presumed to play a role in the regulation of glomerular filtration rate and sodium excretion induced by the family of ANP.

scholarly journals Soluble (pro)renin receptor via β-catenin enhances urine concentration capability as a target of liver X receptor

2016 ◽  
Vol 113 (13) ◽  
pp. E1898-E1906 ◽  
Author(s):  
Xiaohan Lu ◽  
Fei Wang ◽  
Chuanming Xu ◽  
Sunny Soodvilai ◽  
Kexin Peng ◽  
...  
Keyword(s):  
Diabetes Insipidus ◽  
Biological Fluid ◽  
Collecting Duct ◽  
Urine Concentration ◽  
Potential Interaction ◽  
Protein Protein Interaction ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
X Receptors ◽  
Antidiuretic Action

The extracellular domain of the (pro)renin receptor (PRR) is cleaved to produce a soluble (pro)renin receptor (sPRR) that is detected in biological fluid and elevated under certain pathological conditions. The present study was performed to define the antidiuretic action of sPRR and its potential interaction with liver X receptors (LXRs), which are known regulators of urine-concentrating capability. Water deprivation consistently elevated urinary sPRR excretion in mice and humans. A template-based algorithm for protein–protein interaction predicted the interaction between sPRR and frizzled-8 (FZD8), which subsequently was confirmed by coimmunoprecipitation. A recombinant histidine-tagged sPRR (sPRR-His) in the nanomolar range induced a remarkable increase in the abundance of renal aquaporin 2 (AQP2) protein in primary rat inner medullary collecting duct cells. The AQP2 up-regulation relied on sequential activation of FZD8-dependent β-catenin signaling and cAMP–PKA pathways. Inhibition of FZD8 or tankyrase in rats induced polyuria, polydipsia, and hyperosmotic urine. Administration of sPRR-His alleviated the symptoms of diabetes insipidus induced in mice by vasopressin 2 receptor antagonism. Administration of the LXR agonist TO901317 to C57/BL6 mice induced polyuria and suppressed renal AQP2 expression associated with reduced renal PRR expression and urinary sPRR excretion. Administration of sPRR-His reversed most of the effects of TO901317. In cultured collecting duct cells, TO901317 suppressed PRR protein expression, sPRR release, and PRR transcriptional activity. Overall we demonstrate, for the first time to our knowledge, that sPRR exerts antidiuretic action via FZD8-dependent stimulation of AQP2 expression and that inhibition of this pathway contributes to the pathogenesis of diabetes insipidus induced by LXR agonism.

scholarly journals Retinoic Acid Receptor-Dependent, Cell-Autonomous, Endogenous Retinoic Acid Signaling and Its Target Genes in Mouse Collecting Duct Cells

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e45725 ◽  
Author(s):  
Yuen Fei Wong ◽  
Patricia D. Wilson ◽  
Robert J. Unwin ◽  
Jill T. Norman ◽  
Matthew Arno ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Target Genes ◽  
Retinoic Acid Receptor ◽  
Collecting Duct ◽  
Retinoic Acid Signaling ◽  
Acid Receptor ◽  
Duct Cells ◽  
Dependent Cell ◽  
Collecting Duct Cells

scholarly journals miR-34c-5p and CaMKII are involved in aldosterone-induced fibrosis in kidney collecting duct cells

2018 ◽  
Vol 314 (3) ◽  
pp. F329-F342 ◽  
Author(s):  
Eui-Jung Park ◽  
Hyun Jun Jung ◽  
Hyo-Jung Choi ◽  
Jeong-In Cho ◽  
Hye-Jeong Park ◽  
...  
Keyword(s):  
Protein Expression ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Target Genes ◽  
Collecting Duct ◽  
Wnt Signaling Pathway ◽  
Putative Target ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
In Cells

Mineralocorticoids trigger a profibrotic process in the kidney. In mouse cortical collecting duct cells, the present study addressed two main questions: 1) what are microRNAs (miRNAs) and their target genes that are changed by aldosterone? and 2) what do miRNAs, in response to aldosterone, regulate regarding signaling pathways related to fibrosis? A microarray chip assay was done in cells in the absence or presence of aldosterone treatment (10−6M; 3 days). The candidate miRNAs were identified by the criteria of >30% of fold change among the significantly changed miRNAs ( P < 0.05). Twenty-nine miRNAs were upregulated (>1.3-fold), and 27 miRNAs were downregulated (<0.7-fold). Putative target genes of identified miRNAs were associated with 74 Kyoto Encyclopedia of Genes and Genomes pathways. Among them, the wingless-related integration site (Wnt) signaling pathway was highly ranked, where 15 mature miRNAs were observed. These miRNAs were further analyzed by real-time quantitative PCR, and among them, miR-130b-3p, miR-34c-5p, and miR-146a-5p were selected. Through the identification of putative target genes of these three miRNAs, mRNA and protein expression of the Ca2+/calmodulin-dependent protein kinase type II β-chain ( Camk2b) gene (a target gene of miR-34c-5p) were found to be increased significantly in aldosterone-treated cells, where fibronectin (FN) and α-smooth muscle actin were induced. When CaMKIIβ small interfering RNA or the miR-34c-5p mimic was transfected, aldosterone-induced FN expression was significantly attenuated, along with reduced CaMKIIβ protein expression. A luciferase reporter assay revealed a decrease of CaMKIIβ translation in cells transfected with miRNA mimics of miR-34c-5p. In conclusion, aldosterone-induced downregulation of miR-34c-5p in the Wnt signaling pathway and a consequent increase of CaMKIIβ expression are likely to be involved in aldosterone-induced fibrosis.

scholarly journals MP034CHANGES OF MICRORNAS AND TARGET GENES IN MOUSE CORTICAL COLLECTING DUCT CELLS TREATED BY ALDOSTERONE

2017 ◽  
Vol 32 (suppl_3) ◽  
pp. iii439-iii439
Author(s):  
Eui-Jung Park ◽  
Hyun Jun Jung ◽  
Hyo-Jung Choi ◽  
Tae-Hwan Kwon
Keyword(s):  
Target Genes ◽  
Collecting Duct ◽  
Cortical Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells

Abstract 408: Hyperglycemia Increases the Prorenin Receptor in the Plasma Membrane of Collecting Duct Cells in Rats with Type 1 Diabetes Mellitus

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Minolfa C Prieto ◽  
Danielle Y Arita ◽  
Camille T Bourgeois ◽  
Ryousuke Satou
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Ang Ii ◽  
Duct Cells ◽  
Prorenin Receptor ◽  
Collecting Duct Cells ◽  
Tubulointerstitial Inflammation

In type 1 diabetes mellitus (T1DM) there is increased prorenin secretion by the principal cells of the collecting duct. Binding of prorenin to prorenin receptor (PRR) on intercalated cells increases its catalytic activity, increases local angiotensin (Ang) II formation, and stimulates intracellular MAPK signaling responsible for inflammation and tissue fibrosis. Thus, changes in the amount of membrane bound PRR may be a key factor in stimulating these pathways. However, it has not been established that activation of PRR in the collecting duct contributes to increased intrarenal Ang II and tubulointerstitial inflammation via stimulation of inflammatory pathways including transforming growth factor-beta (TGF-β). This study tested the hypothesis that hyperglycemia increases the PRR abundance at the plasma membrane (PM) in the collecting duct cells, thus allowing greater capability to be activated by locally produced prorenin. Streptozotocin (STZ; 60 mg/kg; ip single dose) was used to induce T1DM in Sprague-Dawley rats (N=10) and compared to control rats (N=8). After 7-days induction, STZ-rats showed plasma glucose levels of 428±13 vs. 138±9 mg/dL and insulin of 0.05±0.02 vs. 2.4±0.6 ng/mL, compared to control. Although PRR transcript in the renal medulla were not different between groups; PRR localized predominantly on the apical aspects of collecting duct cells in STZ-induced rats; while in controls it was primarily found intracellularlly. These changes were accompanied by greater levels of active renin and Ang II in the urine and increased TGF-β mRNA levels in the renal medulla of STZ-rats (Renin: 186± 34 vs. 6± 3 ng Ang I/mL/h; P<0.01; Ang II: 884± 147 vs. 42± 14 fmol/h; P<0.05; TGF-β: 1.22 ± 0.06 vs. 0.97 ± 0.03 mRNA ratio; P<0.01). To further assess if hyperglycemia induced in vitro PRR trafficking alterations, collecting duct M-1 cells were treated with normal glucose (NG; 1mM glucose + 1 mM mannitol) and high glucose (HG; 4mM) for 5, 60, and 360 min. PRR protein levels were higher in the PM fractions in cells treated with HG, compared to cells treated with NG. Thus, hyperglycemia increases PRR abundance in the PM of the collecting duct and stimulates TGF-β synthesis in the renal medulla which may underlie the development of tubulointerstitial inflammation.

scholarly journals Telomerase immortalization of principal cells from mouse collecting duct

2010 ◽  
Vol 299 (6) ◽  
pp. F1507-F1514 ◽  
Author(s):  
Stacy L. Steele ◽  
Yongren Wu ◽  
Robert J. Kolb ◽  
Monika Gooz ◽  
Courtney J. Haycraft ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Collecting Duct ◽  
Whole Cell ◽  
Renal Epithelial Cells ◽  
Principal Cells ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Well Differentiated

Recently, the use of overexpression of telomerase reverse transcriptase (TERT) has led to the generation of immortalized human cell lines. However, this cell immortalization approach has not been reported in well-differentiated mouse cells, such as renal epithelial cells. We sought to establish and then characterize a mouse collecting duct cell line, using ectopic expression of mTERT. Isolated primary cortical collecting duct (CCD) cell lines were transduced with mouse (m)TERT, using a lentiviral vector. mTERT-negative cells did not survive blasticidin selection, whereas mTERT-immortalized cells proliferated in selection media for over 40 subpassages. mTERT messenger RNA and telomerase activity was elevated in these cells, compared with an SV40-immortalized cell line. Flow cytometry with Dolichos biflorus agglutinin was used to select the CCD principal cells, and we designated this cell line mTERT-CCD. Cells were well differentiated and exhibited morphological characteristics typically found in renal epithelial cells, such as tight junction formation, microvilli, and primary cilia. Further characterization using standard immunofluorescence revealed abundant expression of aquaporin-2 and the vasopressin type 2 receptor. mTERT-CCD cells exhibited cAMP-stimulated/benzamil-inhibited whole cell currents. Whole cell patch-clamp currents were also enhanced after a 6-day treatment with aldosterone. In conclusion, we have successfully used mTERT to immortalize mouse collecting duct cells that retain the basic in vivo phenotypic characteristics of collecting duct cells. This technique should be valuable in generating cell lines from genetically engineered mouse models.

scholarly journals Angiotensin II increases fibronectin and collagen I through the β-catenin-dependent signaling in mouse collecting duct cells

2015 ◽  
Vol 308 (4) ◽  
pp. F358-F365 ◽  
Author(s):  
Catherina A. Cuevas ◽  
Alexis A. Gonzalez ◽  
Nibaldo C. Inestrosa ◽  
Carlos P. Vio ◽  
Minolfa C. Prieto
Keyword(s):  
Angiotensin Ii ◽  
Target Genes ◽  
Collecting Duct ◽  
Receptor Activation ◽  
Collagen I ◽  
Ang Ii ◽  
Protein Levels ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Gsk 3Β

The contribution of angiotensin II (ANG II) to renal and tubular fibrosis has been widely reported. Recent studies have shown that collecting duct cells can undergo mesenchymal transition suggesting that collecting duct cells are involved in interstitial fibrosis. The Wnt/β-catenin signaling pathway plays an essential role in development, organogenesis, and tissue homeostasis; however, the dysregulation of this pathway has been linked to fibrosis. In this study, we investigated whether AT1receptor activation induces the expression of fibronectin and collagen I via the β-catenin pathway in mouse collecting duct cell line M-1. ANG II (10−7M) treatment in M-1 cells increased mRNA, protein levels of fibronectin and collagen I, the β-catenin target genes (cyclin D1 and c-myc), and the myofibroblast phenotype. These effects were prevented by candesartan, an AT1receptor blocker. Inhibition of the β-catenin degradation with pyrvinium pamoate (pyr; 10−9M) prevented the ANG II-induced expression of fibronectin, collagen I, and β-catenin target genes. ANG II treatment promoted the accumulation of β-catenin protein in a time-dependent manner. Because phosphorylation of glycogen synthase kinase-3β (GSK-3β) inhibits β-catenin degradation, we further evaluated the effects of ANG II and ANG II plus pyr on p-ser9-GSK-3β levels. ANG II-dependent upregulation of β-catenin protein levels was correlated with GSK-3β phosphorylation. These effects were prevented by pyr. Our data indicate that in M-1 collecting duct cells, the β-catenin pathway mediates the stimulation of fibronectin and collagen I in response to AT1receptor activation.

Sign in / Sign up

Export Citation Format

Share Document