scholarly journals Angiotensin II regulates growth of the developing papillas ex vivo

2012 ◽  
Vol 302 (9) ◽  
pp. F1112-F1120 ◽  
Author(s):  
Renfang Song ◽  
Graeme Preston ◽  
Ali Khalili ◽  
Samir S. El-Dahr ◽  
Ihor V. Yosypiv
Keyword(s):  
Caspase 3 ◽  
Ex Vivo ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Collagen Matrix ◽  
Duct Cell ◽  
Ang Ii ◽  
Expression Of Genes ◽  
Integrin Gene ◽  
Α3 Integrin

We tested the hypothesis that lack of angiotensin (ANG) II production in angiotensinogen ( AGT)-deficient mice or pharmacologic antagonism of ANG II AT1 receptor (AT1R) impairs growth of the developing papillas ex vivo, thus contributing to the hypoplastic renal medulla phenotype observed in AGT- or AT 1 R-null mice. Papillas were dissected from Hoxb7GFP+ or AGT+/+, +/−, −/− mouse metanephroi on postnatal day P3 and grown in three-dimentional collagen matrix gels in the presence of media (control), ANG II (10−5 M), or the specific AT1R antagonist candesartan (10−6 M) for 24 h. Percent reduction in papillary length was attenuated in AGT+/+ and in AGT+/− compared with AGT−/− (−18.4 ± 1.3 vs. −32.2 ± 1.6%, P < 0.05, −22.8 ± 1.3 vs. −32.2 ± 1.6%, P < 0.05, respectively). ANG II blunted the decrease in papilla length observed in respective media-treated controls in Hoxb7GFP+ (−1.5 ± 0.3 vs. −10.0 ± 1.4%, P < 0.05) or AGT+/+, +/−, and −/− papillas (−12.8 ± 0.7 vs. −18.4 ± 1.3%, P < 0.05, −16.8 ± 1.1 vs. −23 ± 1.2%, P < 0.05; −26.2 ± 1.6 vs. −32.2 ± 1.6%, P < 0.05, respectively). In contrast, percent decrease in the length of Hoxb7GFP+ papillas in the presence of the AT1R antagonist candesartan was higher compared with control (−24.3 ± 2.1 vs. −10.5 ± 1.8%, P < 0.05). The number of proliferating phospho-histone H3 (pH3)-positive collecting duct cells was lower, whereas the number of caspase 3-positive cells undergoing apoptosis was higher in candesartan- vs. media-treated papillas (pH3: 12 ± 1.4 vs. 21 ± 2.1, P < 0.01; caspase 3: 3.8 ± 0.5 vs. 1.7 ± 0.2, P < 0.01). Using quantitative RT-PCR, we demonstrate that AT1R signaling regulates the expression of genes implicated in morphogenesis of the renal medulla. We conclude that AT1R prevents shrinkage of the developing papillas observed ex vivo via control of Wnt7b, FGF7, β-catenin, calcineurin B1, and α3 integrin gene expression, collecting duct cell proliferation, and survival.

scholarly journals Site-1 Protease-Derived Soluble (Pro)Renin Receptor Contributes to Angiotensin II–Induced Hypertension in Mice

Hypertension ◽  
2020 ◽  
Author(s):  
Ye Feng ◽  
Kexin Peng ◽  
Renfei Luo ◽  
Fei Wang ◽  
Tianxin Yang
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Collecting Duct ◽  
Short Circuit ◽  
Ussing Chamber ◽  
Short Circuit Current ◽  
Duct Cell ◽  
Ang Ii ◽  
Cortical Collecting Duct ◽  
Induced Hypertension

Activation of PRR ([pro]renin receptor) contributes to enhancement of intrarenal RAS and renal medullary α-ENaC and thus elevated blood pressure during Ang II (angiotensin II) infusion. The goal of the present study was to test whether such action of PRR was mediated by sPRR (soluble PRR), generated by S1P (site-1 protease), a newly identified PRR cleavage protease. F1 B6129SF1/J mice were infused for 6 days with control or Ang II at 300 ng/kg per day alone or in combination with S1P inhibitor PF-429242 (PF), and blood pressure was monitored by radiotelemetry. S1P inhibition significantly attenuated Ang II–induced hypertension accompanied with suppressed urinary and renal medullary renin levels and expression of renal medullary but not renal cortical α-ENaC expression. The effects of S1P inhibition were all reversed by supplement with histidine-tagged sPRR termed as sPRR-His. Ussing chamber technique was performed to determine amiloride-sensitive short-circuit current, an index of ENaC activity in confluent mouse cortical collecting duct cell line cells exposed for 24 hours to Ang II, Ang II + PF, or Ang II + PF + sPRR-His. Ang II–induced ENaC activity was blocked by PF, which was reversed by sPRR-His. Together, these results support that S1P-derived sPRR mediates Ang II–induced hypertension through enhancement of intrarenal renin level and activation of ENaC.

NaCl but not urea activates p38 and jun kinase in mIMCD3 murine inner medullary cells

1996 ◽  
Vol 271 (6) ◽  
pp. F1234-F1238 ◽  
Author(s):  
Z. Zhang ◽  
D. M. Cohen
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Duct Cell ◽  
Kinase Assay ◽  
Cellular Protection ◽  
Jun Kinase ◽  
Mitogen Activated Protein ◽  
Dose Dependent ◽  
In Cells

The mitogen-activated protein kinases (MAPKs), p38 and jun kinase (JNK), are activated by diverse stressors in cells of nonrenal medullary origin. Epithelial cells of the renal medulla are among the very few cells of higher eukaryotes routinely subjected to hyperosmotic stress, composed of principally NaCl and urea. Hyperosmotic NaCl activated p38 and JNK in a time- and dose-dependent fashion in cells of the murine terminal inner medullary collecting duct cell line (mIMCD3) as determined by immune complex kinase assay. Hyperosmotic urea exerted a minimal effect upon only p38 activation, which was evident only at 5 min. The NaCl effect was dose dependent to 800 mosmol/kgH2O; 800 mosmol/kgH2O urea, in contrast, exerted no effect. Consistent with these observations, NaCl (800 mosmol/kgH2O) but not urea (800 mosmol/kgH2O) increased tyrosine phosphorylation of p38 and JNK at 10 min. Therefore, even in the extremely osmotolerant renal medullary mIMCD3 cell line, derived from a tissue adapted for routine exposure to elevated osmolality, hypertonic NaCl activated two stress-responsive MAPKs. Urea, in contrast, exerted virtually no effect; therefore, cellular protection from urea stress operates through a mechanism distinct from the stress-responsive MAPKs.

scholarly journals FP050STUDYING MECHANISMS UNDERLYING CYSTOGENESIS IN NPHP6 IN AN EX VIVO MURINE COLLECTING DUCT CELL LINE

2015 ◽  
Vol 30 (suppl_3) ◽  
pp. iii81-iii81
Author(s):  
Shalabh Srivastava ◽  
Ann Marie Hynes ◽  
Colin Miles ◽  
Rachel H Giles ◽  
John A Sayer
Keyword(s):  
Cell Line ◽  
Ex Vivo ◽  
Collecting Duct ◽  
Duct Cell

Abstract P331: Renal Medullary Infusion of BAF312, a Sphingosine-1-phosphate Receptor-1 Agonist, Attenuates Angiotensin II-induced Hypertension

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Qing Zhu ◽  
Junping Hu ◽  
Pin-Lan Li ◽  
Ningjun Li
Keyword(s):  
Collecting Duct ◽  
Renal Medulla ◽  
Ang Ii ◽  
High Salt Diet ◽  
Salt Diet ◽  
Low Salt ◽  
Induced Hypertension ◽  
Sphingosine 1 Phosphate ◽  
S1p Receptor ◽  
Cardiovascular Functions

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite formed by phosphorylation of sphingosine and participates in the regulation of cardiovascular functions. We have recently shown that S1P increases sodium excretion in the renal medulla possibly through inhibiting epithelial sodium channel via the S1P receptor 1 (S1P1), which is mainly localized in collecting ducts with a higher expression level in the renal medulla than the cortex. The present study tested the hypothesis that infusion of an agonist to activate S1P1 in the renal medulla attenuates angiotensin (ANG) II-induced hypertension. Treatment of the mice with a high salt diet (HS, 4% NaCl) for 2 week significantly increased the levels of S1P1 in the renal medulla compared with that in low salt (LS) control by Western blot analysis, whereas this HS-induced increase in S1P1 level was blocked in mice treated with ANG II (600ng/kg/min, sc) (relative S1P1 levels: 1.0±0.19, 1.9±0.14 and 0.9 ±0.18 in LS, HS and HS+ANG II-treated mice, respectively). Infusion of a subpressor dose of ANG II (300ng/kg/min, sc) increased the mean arterial pressure (MAP) in mice with collecting duct-specific knockout of S1P1, but not in S1P1 floxed control mice (MAP: 132±4.7 vs. 96±1.1 mmHg). In contrast, infusion of BAF312, a selective agonist of S1P1, into the renal medulla attenuated the hypertension induced by a pressor dose of ANG II (600 ng/kg/min, sc) in uninephrectomized mice (MAP: 102±1.8, 161 ±7.1 and 133±3.9 in vehicle, ANG II and ANG II+BAF312-treated mice, respectively). These data suggest that inhibition of S1P1 level in the renal medulla may contribute to the pathogenesis of ANG II-induced hypertension and that stimulating the S1P1 pathway may be used as a therapeutic strategy for the treatment of hypertension.

scholarly journals Inhibition of biliverdin reductase increases ANG II-dependent superoxide levels in cultured renal tubular epithelial cells

2009 ◽  
Vol 297 (5) ◽  
pp. R1546-R1553 ◽  
Author(s):  
Shelby C. Young ◽  
Megan V. Storm ◽  
Joshua S. Speed ◽  
Silvia Kelsen ◽  
Chelsea V. Tiller ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Renal Medulla ◽  
Superoxide Production ◽  
Heme Oxygenase 1 ◽  
Ang Ii ◽  
Small Interfering Rnas ◽  
Biliverdin Reductase ◽  
Medullary Collecting Duct ◽  
Renal Tubular ◽  
Antioxidant Effects

Induction of heme oxygenase-1 (HO-1) in the renal medulla increases carbon monoxide and bilirubin production and decreases ANG II-mediated superoxide production. The goal of this study was to determine the importance of increases in bilirubin to the antioxidant effects of HO-1 induction in cultured mouse thick ascending loop of Henle (TALH) and inner medullary collecting duct (IMCD3) cells. Bilirubin levels were decreased by using small interfering RNAs (siRNAs) targeted to biliverdin reductase (BVR), which is the cellular enzyme responsible for the conversion of biliverdin to bilirubin. Treatment of cultured TALH or IMCD-3 cells with BVR siRNA (50 or 100 nM) resulted in an 80% decrease in the level of BVR protein and decreased cellular bilirubin levels from 46 ± 5 to 23 ± 4 nM ( n = 4). We then determined the effects of inhibition of BVR on ANG II-mediated superoxide production. Superoxide production induced by ANG II (10−9 M) significantly increased in both TALH and IMCD-3 cells. Treatment of TALH cells with BVR siRNA resulted in a significant increase in ouabain-sensitive rubidium uptake from 95 ± 6 to 122 ± 5% control ( n = 4, P < 0.05). Lastly, inhibition of BVR with siRNA did not prevent the decrease in superoxide levels observed in cells pretreated with the HO-1 inducer, hemin. We conclude that decreased levels of cellular bilirubin increase ANG II-mediated superoxide production and sodium transport; however, increases in bilirubin are not necessary for HO-1 induction to attenuate ANG II-mediated superoxide production.

scholarly journals Renal medullary cyclooxygenase-2 and (pro)renin receptor expression during angiotensin II-dependent hypertension

2014 ◽  
Vol 307 (8) ◽  
pp. F962-F970 ◽  
Author(s):  
Alexis A. Gonzalez ◽  
Torrance Green ◽  
Christina Luffman ◽  
Camille R. T. Bourgeois ◽  
L. Gabriel Navar ◽  
...  
Keyword(s):  
Early Phase ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Cyclooxygenase 2 ◽  
Receptor Expression ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Protein Levels ◽  
Membrane Bound ◽  
Cox 2

The (pro)renin receptor [(P)RR] upregulates cyclooxygenase-2 (COX-2) in inner medullary collecting duct (IMCD) cells through ERK1/2. Intrarenal COX-2 and (P)RR are upregulated during chronic ANG II infusion. However, the duration of COX-2 and (P)RR upregulation has not been determined. We hypothesized that during the early phase of ANG II-dependent hypertension, membrane-bound (P)RR and COX-2 are augmented in the renal medulla, serving to buffer the hypertensinogenic and vasoconstricting effects of ANG II. In Sprague-Dawley rats infused with ANG II (0.4 μg·min−1·kg−1), systolic blood pressure (BP) increased by day 7 (162 ± 5 vs. 114 ± 10 mmHg) and continued to increase by day 14 (198 ± 15 vs. 115 ± 13 mmHg). Membrane-bound (P)RR was augmented at day 3 coincident with phospho-ERK1/2 levels, COX-2 expression, and PGE2 in the renal medulla. In contrast, membrane-bound (P)RR was reduced and COX-2 protein levels were not different from controls by day 14. In cultured IMCD cells, ANG II increased secretion of the soluble (P)RR. In anesthetized rats, COX-2 inhibition decreased the glomerular filtration rate (GFR) and renal blood flow (RBF) during the early phase of ANG II infusion without altering BP. However, at 14 days of ANG II infusions, COX-2 inhibition decreased mean arterial BP (MABP), RBF, and GFR. Thus, during the early phase of ANG II-dependent hypertension, the increased (P)RR and COX-2 expression in the renal medulla may contribute to attenuate the vasoconstrictor effects of ANG II on renal hemodynamics. In contrast, at 14 days the reductions in RBF and GFR caused by COX-2 inhibition paralleled the reduced MABP, suggesting that vasoconstrictor COX-2 metabolites contribute to ANG II hypertension.

Synthesis and secretion of endothelin in a cortical collecting duct cell line

1996 ◽  
Vol 271 (2) ◽  
pp. F330-F339 ◽  
Author(s):  
K. M. Todd-Turla ◽  
X. L. Zhu ◽  
X. Shu ◽  
M. Chen ◽  
T. Yu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Function ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Duct Cell ◽  
Sodium Absorption ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Collecting Duct Cells ◽  
High Inhibition

Previous experiments have shown that epithelial cells in the renal medulla produce endothelin-1 (ET-1) and possess ETB receptors. It has been suggested that medullary ET-1 may affect water and sodium absorption along the collecting ducts in an autocrine fashion. To study possible mechanisms responsible for the regulation of medullary ET-1 production, experiments were performed in M-1 cells and mIMCD-K2 cells, cell lines derived from cortical and inner medullary collecting ducts of SV40 transgenic mice, grown to confluence on collagen-coated filter inserts. Both cell lines were found to express ET-1 mRNA and to secrete ET almost exclusively into the basolateral medium as long as the transepithelial resistance was high. Inhibition of transcription with actinomycin D was followed by a decline in both ET mRNA [halftime (t1/2) = 30 min] and ET secretion (t1/2 = approximately 90 min). The addition of arginine vasopressin (AVP, 10(-8) M; 2- or 4-h exposure) or incubation of M-1 cells in hypertonic media (+50 mM NaCl, 4- or 6-h exposure) did not significantly alter ET secretion or ET-1 mRNA expression. In contrast, simultaneously increasing AVP(10(-8) M in the basolateral medium) and tonicity (+50 mM NaCl) for 4 h increased ET secretion (from 28.9 +/- 3.9 to 41.8 +/- 3.8 pg.h-1.mg protein-1; P = 0.029, n = 10) and ET-1 mRNA (control = 2,138 cpm/microliter, log of 3.33 +/- 0.048, n = 4; AVP + NaCl = 3,548.1 cpm/microliter, log of 3.55 +/- 0.09; P = 0.045, n = 5). Exposure of M-1 cells to hypertonic media (+50 mM NaCl or 100 mM mannitol) for 24 h was associated with a marked reduction of ET secretion (-83.9% with NaCl and -78.4% with mannitol; P < 0.0001). This reduction was attenuated, but not prevented, by the presence of AVP in the basolateral medium (-40%). ET-1 mRNA, in contrast, did not change with 24-h exposure to hypertonic media and increased when AVP was present. Results are compatible with the concept that generation of ET by collecting duct cells may contribute in a complex and time-dependent fashion to the paracrine control of collecting duct cell function.

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.

Genetic deletion of the P2Y2 receptor offers significant resistance to development of lithium-induced polyuria accompanied by alterations in PGE2 signaling

2012 ◽  
Vol 302 (1) ◽  
pp. F70-F77 ◽  
Author(s):  
Yue Zhang ◽  
Ioana L. Pop ◽  
Noel G. Carlson ◽  
Bellamkonda K. Kishore
Keyword(s):  
Ex Vivo ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Urine Osmolality ◽  
Protein Abundance ◽  
P2y2 Receptor ◽  
Dietary Regimen ◽  
Medullary Collecting Duct ◽  
Genetic Deletion ◽  
Camp Levels

Lithium (Li)-induced polyuria is due to resistance of the medullary collecting duct (mCD) to the action of arginine vasopressin (AVP), apparently mediated by increased production of PGE2. We previously reported that the P2Y2 receptor (P2Y2-R) antagonizes the action of AVP on the mCD and may play a role in Li-induced polyuria by enhancing the production of PGE2 in mCD. Hence, we hypothesized that genetic deletion of P2Y2-R should ameliorate Li-induced polyuria. Wild-type (WT) or P2Y2-R knockout (KO) mice were fed normal or Li-added diets for 14 days and euthanized. Li-induced polyuria, and decreases in urine osmolality and AQP2 protein abundance in the renal medulla, were significantly less compared with WT mice despite the lack of differences in Li intake or terminal serum or inner medullary tissue Li levels. Li-induced increased urinary excretion of PGE2 was not affected in KO mice. However, prostanoid EP3 receptor (EP3-R) protein abundance in the renal medulla of KO mice was markedly lower vs. WT mice, irrespective of the dietary regimen. The protein abundances of other EP-Rs were not altered across the groups irrespective of the dietary regimen. Ex vivo stimulation of mCD with PGE2 generated significantly more cAMP in Li-fed KO mice (130%) vs. Li-fed WT mice (100%). Taken together, these data suggest 1) genetic deletion of P2Y2-R offers significant resistance to the development of Li-induced polyuria; and 2) this resistance is apparently due to altered PGE2 signaling mediated by a marked decrease in EP3-R protein abundance in the medulla, thus attenuating the EP3-mediated decrease in cAMP levels in mCD.

Sign in / Sign up

Export Citation Format

Share Document