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.

Abstract 214: (pro) Renin Receptor Stimulates the Expression of Fibrotic Genes in Mouse Collecting Ducts Cells via Wnt/β-catenin Signaling, Independently of Angiotensin II

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Catherina A Cuevas ◽  
Alexis A Gonzalez ◽  
Nivaldo C Inestrosa ◽  
Carlos P Vio ◽  
Minolfa C Prieto
Keyword(s):  
Angiotensin Ii ◽  
Wnt Signaling ◽  
Cyclin D1 ◽  
Target Genes ◽  
Collecting Duct ◽  
Fold Change ◽  
Collagen I ◽  
Ang Ii ◽  
Protein Levels ◽  
Prorenin Receptor

The prorenin receptor (PRR) is upregulated in the kidney by high angiotensin II (Ang II) states such as those that occur with AngII-dependent hypertension and low salt diet. The PRR is an accessory protein of the vacuolar H-ATPase, which facilitates Wnt/β-catenin signaling. The Wnt/β-catenin pathway is involved in fibrosis processes. In the present study, we aimed to determine whether the stimulation of PRR in mouse collecting duct M-1 cells induces fibrotic genes independently of Ang II, and if this effect is mediated by activation of Wnt/β-catenin. Both Ang II (10 -7 M) and human recombinant prorenin (hRPr; 2,5 x 10 -8 M) treatments (8 and 16 hours) increased mRNA and protein levels of fibronectin and collagen I (1.5±0.08 and 1.5 ± 0.1 fold change, respectibely; p<0.05); however, the effects of hRPr were elicited earlier. Likewise, Ang II and hRPr stimulated the Wnt target genes, cyclin D1 and c-myc (cyclin D1: 2±0.2 for both; c-myc: 1.4 ± 0.03 and 1.2± 0.002 fold change for Ang II and hRPr, respectively; p<0.001). Ang II type 1 receptor (AT1R) blockade with candesartan (10 -7 M) completely prevented the Ang II-dependent stimulation but not the effects of hRPr on Wnt signaling genes. Upregulation of fibronectin and collagen I genes by Ang II or hRP at 16 h was prevented by Wnt signaling inhibition with Pyrvinium Pamoate (10 -7 M). The data indicate that in M-1 cells, activation of AT1R and PRR stimulate the synthesis of fibrotic genes via Wnt signaling by independent mechanisms.

scholarly journals The Angiotensin II Type 1 Receptor-Associated Protein Attenuates Angiotensin II-Mediated Inhibition of the Renal Outer Medullary Potassium Channel in Collecting Duct Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Juliano Zequini Polidoro ◽  
Nancy Amaral Rebouças ◽  
Adriana Castello Costa Girardi
Keyword(s):  
Angiotensin Ii ◽  
Cell Surface ◽  
Collecting Duct ◽  
Cell Surface Expression ◽  
Ang Ii ◽  
Cortical Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells

Adjustments in renal K+ excretion constitute a central mechanism for K+ homeostasis. The renal outer medullary potassium (ROMK) channel accounts for the major K+ secretory route in collecting ducts during basal conditions. Activation of the angiotensin II (Ang II) type 1 receptor (AT1R) by Ang II is known to inhibit ROMK activity under the setting of K+ dietary restriction, underscoring the role of the AT1R in K+ conservation. The present study aimed to investigate whether an AT1R binding partner, the AT1R-associated protein (ATRAP), impacts Ang II-mediated ROMK regulation in collecting duct cells and, if so, to gain insight into the potential underlying mechanisms. To this end, we overexpressed either ATRAP or β-galactosidase (LacZ; used as a control), in M-1 cells, a model line of cortical collecting duct cells. We then assessed ROMK channel activity by employing a novel fluorescence-based microplate assay. Experiments were performed in the presence of 10−10 M Ang II or vehicle for 40 min. We observed that Ang II-induced a significant inhibition of ROMK in LacZ, but not in ATRAP-overexpressed M-1 cells. Inhibition of ROMK-mediated K+ secretion by Ang II was accompanied by lower ROMK cell surface expression. Conversely, Ang II did not affect the ROMK-cell surface abundance in M-1 cells transfected with ATRAP. Additionally, diminished response to Ang II in M-1 cells overexpressing ATRAP was accompanied by decreased c-Src phosphorylation at the tyrosine 416. Unexpectedly, reduced phospho-c-Src levels were also found in M-1 cells, overexpressing ATRAP treated with vehicle, suggesting that ATRAP can also downregulate this kinase independently of Ang II-AT1R activation. Collectively, our data support that ATRAP attenuates inhibition of ROMK by Ang II in collecting duct cells, presumably by reducing c-Src activation and blocking ROMK internalization. The potential role of ATRAP in K+ homeostasis and/or disorders awaits further investigation.

scholarly journals Vasopressin/V2 receptor stimulates renin synthesis in the collecting duct

2016 ◽  
Vol 310 (4) ◽  
pp. F284-F293 ◽  
Author(s):  
Alexis A. Gonzalez ◽  
Flavia Cifuentes-Araneda ◽  
Cristobal Ibaceta-Gonzalez ◽  
Alex Gonzalez-Vergara ◽  
Leonardo Zamora ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Critical Role ◽  
Combined Treatment ◽  
Receptor Activation ◽  
Ang Ii ◽  
Principal Cells ◽  
Protein Levels ◽  
Renin Synthesis ◽  
Renin Mrna ◽  
Creb Pathway

Renin is synthesized in the principal cells of the collecting duct (CD), and its production is increased via cAMP in angiotensin (ANG) II-dependent hypertension, despite suppression of juxtaglomerular (JG) renin. Vasopressin, one of the effector hormones of the renin-angiotensin system (RAS) via the type 2-receptor (V2R), activates the cAMP/PKA/cAMP response element-binding protein (CREB) pathway and aquaporin-2 expression in principal cells of the CD. Accordingly, we hypothesized that activation of V2R increases renin synthesis via PKA/CREB, independently of ANG II type 1 (AT1) receptor activation in CD cells. Desmopressin (DDAVP; 10−6 M), a selective V2R agonist, increased renin mRNA (∼3-fold), prorenin (∼1.5-fold), and renin (∼2-fold) in cell lysates and cell culture media in the M-1 CD cell line. Cotreatment with DDAVP+H89 (PKA inhibitor) or CREB short hairpin (sh) RNA prevented this response. H89 also blunted DDAVP-induced CREB phosphorylation and nuclear localization. In 48-h water-deprived (WD) mice, prorenin-renin protein levels were increased in the renal inner medulla (∼1.4- and 1.8-fold). In WD mice treated with an ACE inhibitor plus AT1 receptor blockade, renin mRNA and prorenin protein levels were still higher than controls, while renin protein content was not changed. In M-1 cells, ANG II or DDAVP increased prorenin-renin protein levels; however, there were no further increases by combined treatment. These results indicate that in the CD the activation of the V2R stimulates renin synthesis via the PKA/CREB pathway independently of RAS, suggesting a critical role for vasopressin in the regulation of renin in the CD.

scholarly journals Collecting duct-specific knockout of renin attenuates angiotensin II-induced hypertension

2014 ◽  
Vol 307 (8) ◽  
pp. F931-F938 ◽  
Author(s):  
Nirupama Ramkumar ◽  
Deborah Stuart ◽  
Sara Rees ◽  
Alfred Van Hoek ◽  
Curt D. Sigmund ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Collecting Duct ◽  
Plasma Renin ◽  
Ang Ii ◽  
Water Excretion ◽  
Protein Levels ◽  
Renin Gene ◽  
Induced Hypertension ◽  
Renin Mrna ◽  
Exon 1

The physiological and pathophysiological significance of collecting duct (CD)-derived renin, particularly as it relates to blood pressure (BP) regulation, is unknown. To address this question, we generated CD-specific renin knockout (KO) mice and examined BP and renal salt and water excretion. Mice containing loxP-flanked exon 1 of the renin gene were crossed with mice transgenic for aquaporin-2-Cre recombinase to achieve CD-specific renin KO. Compared with controls, CD renin KO mice had 70% lower medullary renin mRNA and 90% lower renin mRNA in microdissected cortical CD. Urinary renin levels were significantly lower in KO mice (45% of control levels) while plasma renin concentration was significantly higher in KO mice (63% higher than controls) during normal-Na intake. While no observable differences were noted in BP between the two groups with varying Na intake, infusion of angiotensin II at 400 ng·kg−1·min−1 resulted in an attenuated hypertensive response in the KO mice (mean arterial pressure 111 ± 4 mmHg in KO vs. 128 ± 3 mmHg in controls). Urinary renin excretion and epithelial Na+ channel (ENaC) remained significantly lower in the KO mice following ANG II infusion compared with controls. Furthermore, membrane-associated ENaC protein levels were significantly lower in KO mice following ANG II infusion. These findings suggest that CD renin modulates BP in ANG II-infused hypertension and these effects are associated with changes in ENaC expression.

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.

Increased AQP2 targeting in primary cultured IMCD cells in response to angiotensin II through AT1 receptor

2007 ◽  
Vol 292 (1) ◽  
pp. F340-F350 ◽  
Author(s):  
Yu-Jung Lee ◽  
In-Kyung Song ◽  
Kyung-Jin Jang ◽  
Jakob Nielsen ◽  
Jørgen Frøkiær ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Angiotensin Ii ◽  
Collecting Duct ◽  
Receptor Activation ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Water Reabsorption ◽  
Sprague Dawley Rats ◽  
Medullary Collecting Duct ◽  
Camp Levels

Vasopressin and angiotensin II (ANG II) play a major role in renal water and Na+ reabsorption. We previously demonstrated that ANG II AT1 receptor blockade decreases dDAVP-induced water reabsorption and AQP2 levels in rats, suggesting cross talk between these two peptide hormones ( Am J Physiol Renal Physiol 288: F673–F684, 2005). To directly address this issue, primary cultured inner medullary collecting duct (IMCD) cells from male Sprague-Dawley rats were treated for 15 min with 1) vehicle, 2) ANG II, 3) ANG II + the AT1 receptor blocker candesartan, 4) dDAVP, 5) ANG II + dDAVP, or 6) ANG II + dDAVP + candesartan. Immunofluorescence microscopy revealed that 10−8 M ANG II or 10−11 M dDAVP ( protocol 1) was associated with increased AQP2 labeling of the plasma membrane and decreased cytoplasmic labeling, respectively. cAMP levels increased significantly in response to 10−8 M ANG II and were potentiated by cotreatment with 10−11 M dDAVP. Consistent with this finding, immunoblotting revealed that this cotreatment significantly increased expression of phosphorylated AQP2. ANG II-induced AQP2 targeting was blocked by 10−5 M candesartan. In protocol 2, treatment with a lower concentration of dDAVP (10−12 M) or ANG II (10−9 M) did not change subcellular AQP2 distribution, whereas 10−12 M dDAVP + 10−9 M ANG II enhanced AQP2 targeting. This effect was inhibited by cotreatment with 10−5 M candesartan. ANG II-induced cAMP accumulation and AQP2 targeting were inhibited by inhibition of PKC activity. In conclusion, ANG II plays a role in the regulation of AQP2 targeting to the plasma membrane in IMCD cells through AT1 receptor activation and potentiates the effect of dDAVP on AQP2 plasma membrane targeting.

scholarly journals Interaction between vasopressin and angiotensin II in vivo and in vitro: effect on aquaporins and urine concentration

2010 ◽  
Vol 299 (3) ◽  
pp. F577-F584 ◽  
Author(s):  
Weidong Wang ◽  
Chunling Li ◽  
Sandra Summer ◽  
Sandor Falk ◽  
Robert W. Schrier
Keyword(s):  
Angiotensin Ii ◽  
Collecting Duct ◽  
Receptor Activation ◽  
Urine Concentration ◽  
At1 Receptor ◽  
Receptor Blockade ◽  
Ang Ii ◽  
Vitro Effect

The study was undertaken to examine the potential cross talk between vasopressin and angiotensin II (ANG II) intracellular signaling pathways. We investigated in vivo and in vitro whether vasopressin-induced water reabsorption could be attenuated by ANG II AT1 receptor blockade (losartan). On a low-sodium diet (0.5 meq/day) dDAVP-treated animals with or without losartan exhibited comparable renal function [creatinine clearance 1.2 ± 0.1 in dDAVP+losartan (LSDL) vs. 1.1 ± 0.1 ml·100 g−1·day−1 in dDAVP alone (LSD), P > 0.05] and renal blood flow (6.3 ± 0.5 in LSDL vs. 6.8 ± 0.5 ml/min in LSD, P > 0.05). The urine output, however, was significantly increased in LSDL (2.5 ± 0.2 vs. 1.8 ± 0.2 ml·100 g−1·day−1, P < 0.05) in association with decreased urine osmolality (2,600 ± 83 vs. 3,256 ± 110 mosmol/kgH2O, P < 0.001) compared with rats in LSD. Immunoblotting revealed significantly decreased expression of medullary AQP2 (146 ± 6 vs. 176 ± 10% in LSD, P < 0.01), p-AQP2 (177 ± 13 vs. 214 ± 12% in LSD, P < 0.05), and AQP3 (134 ± 14 vs. 177 ± 11% in LSD, P < 0.05) in LSDL compared with LSD. The expressions of AQP1, the α1- and γ-subunits of Na-K-ATPase, and the Na-K-2Cl cotransporter were not different among groups. In vitro studies showed that ANG II or dDAVP treatment was associated with increased AQP2 expression and cAMP levels, which were potentiated by cotreatment with ANG II and dDAVP and were inhibited by AT1 blockade. In conclusion, ANG II AT1 receptor blockade in dDAVP-treated rats on a low-salt diet was associated with decreased urine concentration and decreased inner medullary AQP2, p-AQP2, and AQP3 expression, suggesting that AT1 receptor activation plays a significant role in regulating aquaporin expression and modulating urine concentration in vivo. Studies in collecting duct cells were confirmatory.

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