scholarly journals Superoxide increases surface NKCC2 in the rat thick ascending limbs via PKC

2019 ◽  
Vol 317 (1) ◽  
pp. F99-F106 ◽  
Author(s):  
Mohammed Ziaul Haque ◽  
Pablo A. Ortiz
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Xanthine Oxidase ◽  
Apical Membrane ◽  
No Production ◽  
Thick Ascending Limb ◽  
Apical Surface ◽  
Kinase C ◽  
Apical Trafficking ◽  
Enhanced Surface

The apical Na+-K+-2Cl− cotransporter (NKCC2) mediates NaCl reabsorption by the thick ascending limb (TAL). The free radical superoxide ([Formula: see text]) stimulates TAL NaCl absorption by enhancing NKCC2 activity. In contrast, nitric oxide (NO) scavenges [Formula: see text] and inhibits NKCC2. NKCC2 activity depends on the number of NKCC2 transporters in the TAL apical membrane and its phosphorylation. We hypothesized that [Formula: see text] stimulates NKCC2 activity by enhancing apical surface NKCC2 expression. We measured surface NKCC2 expression in rat TALs by surface biotinylation and Western blot analysis. Treatment of TALs with [Formula: see text] produced by exogenous xanthine oxidase (1 mU/ml) and hypoxanthine (500 µM) stimulated surface NKCC2 expression by ~18 ± 5% ( P < 0.05). [Formula: see text]-stimulated surface NKCC2 expression was blocked by the [Formula: see text] scavenger tempol (50 µM). Scavenging H2O2 with 100 U/ml catalase did not block the stimulatory effect of xanthine oxidase-hypoxanthine (22 ± 8% increase from control, P < 0.05). Inhibition of endogenous NO production with Nω-nitro-l-arginine methyl ester enhanced surface NKCC2 expression by 21 ± 6% and, when added together with xanthine oxidase-hypoxanthine, increased surface NKCC2 by 41 ± 10% ( P < 0.05). Scavenging [Formula: see text] with superoxide dismutase (300 U/ml) decreased this stimulatory effect by 60% (39 ± 4% to 15 ± 10%, P < 0.05). Protein kinase C inhibition with Gö-6976 (100 nM) blocked [Formula: see text]-stimulated surface NKCC2 expression ( P < 0.05). [Formula: see text] did not affect NKCC2 phosphorylation at Thr96/101 or its upstream kinases STE20/SPS1-related proline/alanine-rich kinase-oxidative stress-responsive kinase 1. We conclude that [Formula: see text] increases surface NKCC2 expression by stimulating protein kinase C and that this effect is blunted by endogenous NO. [Formula: see text]-stimulated apical trafficking of NKCC2 may be involved in the enhanced surface NKCC2 expression observed in Dahl salt-sensitive rats.

Alterations in surface substructure and degranulation of subapical cytoplasmic granules by mezereinu (MZ) in toad urinary bladder epithelia

1989 ◽  
Vol 47 ◽  
pp. 916-917
Author(s):  
A. J. Mia ◽  
L. X. Oakfoid ◽  
T. Yorio
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Urinary Bladder ◽  
Water Flow ◽  
Apical Membrane ◽  
Water Channels ◽  
Phosphoinositide Metabolism ◽  
Apical Surface ◽  
Ultrastructural Studies ◽  
Kinase C

The increase in transepithelial water flow induced by antidiuretic hormone (ADH) occurs through the ADH V2 receptor, and includes the stimulation of adenylcyclase, an increase in cAMP synthesis and the activation of protein kinase A. These biochemical events in amphibian urinary bladder tissues are reported to be accompanied by apical membrane transformations including the induction of numerous microvilli, and an increase in apical surface area as a result of incorporation of water channels. Amphibian epithelia also contain an ADH V1 receptor coupled to phosphoinositide metabolism and inositol phosphate release. Recently, it was demonstrated that mezerein (MZ), a non-phorbol activator of protein kinase C (PKC)increased transepithelial water flow when added to mucosal surface. The magnitude of water transport was less and occurred over a longer period of time than compared to ADH-stimulated tissues (7,and also Table 1). However, there is little or no information available on ultrastructural studies linking the events due to the ADH V1 receptor and osmotic water flow. Presently, we report on morphological and cytological observations which suggests that the ADH V1 receptor cascade may play a role in the insertion of water channels into the apical membrane possibly through the activation of PKC. The present study utilizes mezerein (MZ), a non-phorbol activator of protein kinase C (PKC) to examine the effect of MZ on epithelial cytomorphology.

ANG II controls Na+-K+( NH 4 + )-2Cl−cotransport via 20-HETE and PKC in medullary thick ascending limb

1998 ◽  
Vol 274 (4) ◽  
pp. C1047-C1056 ◽  
Author(s):  
Hassane Amlal ◽  
Christian LeGoff ◽  
Catherine Vernimmen ◽  
Manoocher Soleimani ◽  
Michel Paillard ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Thick Ascending Limb ◽  
Ang Ii ◽  
Diacylglycerol Lipase ◽  
Medullary Thick Ascending Limb ◽  
Kinase C ◽  
Cell Ph ◽  
Cytochrome P 450

Cell pH was monitored in medullary thick ascending limbs to determine effects of ANG II on Na+-K+([Formula: see text])-2Cl−cotransport. ANG II at 10−16to 10−12 M inhibited 30–50% ( P < 0.005), but higher ANG II concentrations were stimulatory compared with the 10−12 M ANG II level cotransport activity; eventually, 10−6 M ANG II stimulated 34% cotransport activity ( P < 0.003). Inhibition by 10−12M ANG II was abolished by phospholipase C (PLC), diacylglycerol lipase, or cytochrome P-450-dependent monooxygenase blockade; 10−12 M ANG II had no effect additive to inhibition by 20-hydroxyeicosatetranoic acid (20-HETE). Stimulation by 10−6 M ANG II was abolished by PLC and protein kinase C (PKC) blockade and was partially suppressed when the rise in cytosolic Ca2+ was prevented. All ANG II effects were abolished by DUP-753 (losartan) but not by PD-123319. Thus ≤10−12 M ANG II inhibits via 20-HETE, whereas ≥5 × 10−11 M ANG II stimulates via PKC Na+-K+([Formula: see text])-2Cl−cotransport; all ANG II effects involve AT1 receptors and PLC activation.

Role of phospholipase C, protein kinase C, and calcium in VEGF-induced venular hyperpermeability

1999 ◽  
Vol 276 (2) ◽  
pp. H535-H542 ◽  
Author(s):  
H. mac Wu ◽  
Yuan Yuan ◽  
David C. Zawieja ◽  
John Tinsley ◽  
Harris J. Granger
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Umbilical Vein ◽  
No Synthase ◽  
Serine Phosphorylation ◽  
No Production ◽  
Vegf Receptor ◽  
Apparent Permeability ◽  
Kinase C

We previously demonstrated that vascular endothelial growth factor (VEGF)-elicited increase in the permeability of coronary venules was blocked by the nitric oxide (NO) synthase inhibitor N G-monomethyl-l-arginine (l-NMMA). The aim of this study was to delineate in more detail the signaling pathways upstream from NO production in VEGF-induced venular hyperpermeability. The apparent permeability coefficient of albumin ( P a) and endothelial cytosolic Ca2+concentration ([Ca2+]i) were measured in intact perfused porcine coronary venules using fluorescence microscopy. VEGF (10−10 M) induced a two- to threefold increase in P a, which was blocked by a monoclonal antibody directed against the VEGF receptor Flk-1/KDR, the phospholipase C (PLC) antagonist U-73122, or the protein kinase C (PKC) antagonist bisindolylmaleimide (BIM). In 12 venules that displayed the [Ca2+]iresponse to bradykinin (10−6M) and ionomycin (10−6 M), only 4 vessels responded to VEGF with a transient increase in [Ca2+]i. Furthermore, Western blot analysis of cultured human umbilical vein endothelial cells showed that VEGF increased tyrosine phosphorylation of PLC-γ and serine phosphorylation of endothelial constitutive NO synthase (ecNOS). The hyperphosphorylation of PLC-γ was greatly attenuated by the KDR receptor antibody and U-73122, but not by BIM orl-NMMA. In contrast, U-73122 and BIM were able to inhibit VEGF-elicited serine phosphorylation of ecNOS. The results suggest that VEGF induces venular hyperpermeability through a KDR receptor-mediated activation of PLC. In turn, ecNOS is activated by PLC-mediated PKC and/or cytosolic Ca2+ elevation stimulation.

Acceleration of trophoblast differentiation by heparin-binding EGF-like growth factor is dependent on the stage-specific activation of calcium influx by ErbB receptors in developing mouse blastocysts

Development ◽  
2000 ◽  
Vol 127 (1) ◽  
pp. 33-44 ◽  
Author(s):  
J. Wang ◽  
L. Mayernik ◽  
J.F. Schultz ◽  
D.R. Armant
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Intracellular Signaling ◽  
Erbb Receptors ◽  
Apical Surface ◽  
Heparin Binding ◽  
Trophoblast Cells ◽  
Trophoblast Differentiation ◽  
Kinase C

Heparin-binding EGF-like growth factor (HB-EGF) is expressed in the mouse endometrial epithelium during implantation exclusively at sites apposed to embryos and accelerates the development of cultured blastocysts, suggesting that it may regulate peri-implantation development in utero. We have examined the influence of HB-EGF on mouse trophoblast differentiation in vitro and the associated intracellular signaling pathways. HB-EGF both induced intracellular Ca2+ signaling and accelerated trophoblast development to an adhesion-competent stage, but only late on gestation day 4 after ErbB4, a receptor for HB-EGF, translocated from the cytoplasm to the apical surface of trophoblast cells. The acceleration of blastocyst differentiation by HB-EGF was attenuated after inhibition of protein tyrosine kinase activity or removal of surface heparan sulfate, as expected. Chelation of intracellular Ca2+ blocked the ability of HB-EGF to accelerate development, as did inhibitors of protein kinase C or calmodulin. The absence of any effect by a phospholipase C inhibitor and the requirement for extracellular Ca2+ suggested that the accrued free cytoplasmic Ca2+ did not originate from inositol phosphate-sensitive intracellular stores, but through Ca2+ influx. Indeed, N-type Ca2+ channel blockers specifically inhibited the ability of HB-EGF to both induce Ca2+ signaling and accelerate trophoblast development. We conclude that HB-EGF accelerates the differentiation of trophoblast cells to an adhesion-competent stage by inducing Ca2+ influx, which activates calmodulin and protein kinase C. An upstream role for ErbB4 in this pathway is implicated by the timing of its translocation to the trophoblast surface.

Extracellular Ca2+ decreases chloride reabsorption in rat CTAL by inhibiting cAMP pathway

1998 ◽  
Vol 275 (2) ◽  
pp. F198-F203 ◽  
Author(s):  
Marie Céleste De Jesus Ferreira ◽  
Claire Bailly
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rat Kidney ◽  
Inhibitory Effect ◽  
Phospholipase A ◽  
Thick Ascending Limb ◽  
Time Control ◽  
Camp Pathway ◽  
Kinase C ◽  
Gf 109203X

The effect of activation of the Ca2+-sensing receptor on net Cl flux ( J Cl) has been investigated on microperfused cortical (C) thick ascending limb (TAL) from rat kidney. Increasing bath Ca2+ from 0.5 to 3 mM or adding 200 μM of the specific Ca2+-sensing receptor agonist neomycin reduced basal as well as antidiuretic hormone (ADH)-stimulated J Cl by 27.7 ± 5.0% and 25.9 ± 4.1%, respectively. J Cl remained unchanged in time control tubules. The effect of neomycin/Ca2+ on J Cl was blocked by two protein kinase A inhibitors, H-9 or H-89, but not by a protein kinase C inhibitor, GF-109203X, regardless of whether ADH was present or not. Moreover, H-89 decreased basal J Cl and prevented a further effect of 3 mM Ca2+. When J Cl was increased by 8-bromo-cAMP plus IBMX, no effect of 3 mM Ca2+ was observed. Inhibitors of phospholipase A2 and cytochrome P-450 monooxygenase failed to modify the effect of 3 mM Ca2+, although these agents dampened significantly the inhibitory effect of bradykinin on medullary TAL. We conclude that extracellular Ca2+ decreases basal and ADH-stimulated Cl reabsorption in CTAL by inhibiting the cAMP pathway, independently of protein kinase C or phospholipase A2 stimulation.

Aldosterone potentiates 1,25-dihydroxyvitamin D3 action in renal thick ascending limb via a nongenomic, ERK-dependent pathway

2003 ◽  
Vol 285 (5) ◽  
pp. C1122-C1130 ◽  
Author(s):  
David W. Good ◽  
Thampi George ◽  
Bruns A. Watts
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Transport ◽  
Thick Ascending Limb ◽  
Dihydroxyvitamin D3 ◽  
Dihydroxyvitamin D ◽  
Cell Functions ◽  
Kinase C ◽  
Extracellular Signal ◽  
Nongenomic Pathway

Recently, we demonstrated that aldosterone inhibits HCO3- absorption in the rat medullary thick ascending limb (MTAL) via a nongenomic pathway blocked by inhibitors of extracellular signal-regulated kinase (ERK) activation. Here we examined the effects on the MTAL of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], which regulates cell functions through nongenomic mechanisms in nonrenal systems. Addition of 1 nM 1,25(OH)2D3 to the bath decreased HCO3- absorption by 24%, from 15.0 ± 0.3 to 11.4 ± 0.5 pmol· min-1· mm-1 ( P < 0.001). This inhibition was maximal within 60 min and was eliminated by pretreatment with actinomycin D, cycloheximide, or inhibitors of protein kinase C. In MTAL bathed with 1 nM aldosterone [added 15-20 min before 1,25(OH)2D3], the absolute (5.6 ± 0.3 vs. 3.6 ± 0.3 pmol· min-1· mm-1) and fractional (49 ± 2 vs. 24 ± 2%) decreases in HCO3- absorption induced by 1,25(OH)2D3 were significantly greater than those in the absence of aldosterone ( P < 0.05). The effect of aldosterone to potentiate inhibition by 1,25(OH)2D3 was not affected by spironolactone but was eliminated by the MAPK kinase/ERK inhibitor U-0126. U-0126 did not affect inhibition of HCO3- absorption by 1,25(OH)2D3 alone. Aldosterone induced rapid activation of ERK via a transcription-independent pathway. We conclude that 1) 1,25(OH)2D3 inhibits HCO3- absorption in the MTAL via a genomic pathway involving protein kinase C, which may contribute to 1,25(OH)2D3-induced regulation of urinary net acid and/or Ca2+ excretion and 2) aldosterone potentiates inhibition by 1,25(OH)2D3 through an ERK-dependent, nongenomic pathway. These results identify a novel regulatory interaction whereby aldosterone acts via nongenomic mechanisms to enhance the genomic response to 1,25(OH)2D3. Aldosterone may influence a broad range of biological processes, including epithelial transport, by modifying the response of target tissues to 1,25(OH)2D3 stimulation.

Regulation of NaCl entry into Necturus gallbladder epithelium by protein kinase C

1994 ◽  
Vol 266 (2) ◽  
pp. C531-C535 ◽  
Author(s):  
R. Dausch ◽  
K. R. Spring
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitors ◽  
Apical Membrane ◽  
Cell Swelling ◽  
Nacl Transport ◽  
Control Value ◽  
Necturus Gallbladder ◽  
Kinase C

The role of protein kinase C in the regulation of the mode of NaCl entry into Necturus gallbladder epithelial cells was determined from the rate and magnitude of ouabain-induced cell swelling in the presence of inhibitors. Stimulation of protein kinase C by phorbol ester increased the rate of cell swelling from the control value of 2.9% to 4.7%/min and caused the predominant apical membrane transport mechanism for NaCl to switch from bumetanide-sensitive Na-Cl cotransport to amiloride-sensitive parallel exchange. Na-Cl cotransport could be restored as the predominant mode of NaCl entry by treatment of stimulated tissues with the kinase inhibitors 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7) and calphostin C. Therefore the mechanism of NaCl transport across the apical membrane can be controlled by the activity of protein kinase C.

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