Regulation of NHE3 by nitric oxide in Caco-2 cells

2002 ◽  
Vol 283 (3) ◽  
pp. G747-G756 ◽  
Author(s):  
Ravinder K. Gill ◽  
Seema Saksena ◽  
Irfan Ali Syed ◽  
Sangeeta Tyagi ◽  
Waddah A. Alrefai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Signal Transduction Pathway ◽  
Specific Protein ◽  
Protein Kinase G ◽  
Kinase A ◽  
Specific Protein Kinase

The effect of nitric oxide (NO) on Na+/H+ exchange (NHE) activity was investigated utilizing Caco-2 cells as an experimental model. Incubation of Caco-2 cells with 10−3 M S-nitroso- N-acetylpenicillamine (SNAP), a conventional donor of NO, for 20 min resulted in a ∼45% dose-dependent decrease in NHE activity, as determined by assay of ethylisopropylamiloride-sensitive 22Na uptake. A similar decrease in NHE activity was observed utilizing another NO-specific donor, sodium nitroprusside. SNAP-mediated inhibition of NHE activity was not secondary to a loss of cell viability. NHE3 activity was significantly reduced by SNAP ( P < 0.05), whereas NHE2 activity was essentially unaltered. The effects of SNAP were mediated by the cGMP-dependent signal transduction pathway as follows: 1) LY-83583 and 1 H-(1,2,4)oxadiazolo(4,3- a)quinoxalin-1-one (ODQ), specific inhibitors of soluble guanylate cyclase, blocked the inhibitory effect of SNAP on NHE; 2) 8-bromo-cGMP mimicked the effects of SNAP on NHE activity; 3) the SNAP-induced decrease in NHE activity was counteracted by a specific protein kinase G inhibitor, KT-5823 (1 μM); 4) chelerythrine chloride (2 μM) or calphostin C (200 nM), specific protein kinase C inhibitors, did not affect inhibition of NHE activity by SNAP; 5) there was no cross activation by the protein kinase A-dependent pathway, as the inhibitory effects of SNAP were not blocked by Rp-cAMPS (25 μM), a specific protein kinase A inhibitor. These data provide novel evidence that NO inhibits NHE3 activity via activation of soluble guanylate cyclase, resulting in an increase in intracellular cGMP levels and activation of protein kinase G.

scholarly journals Matrix-Specific Protein Kinase A Signaling Regulates p21-Activated Kinase Activation by Flow in Endothelial Cells

2010 ◽  
Vol 106 (8) ◽  
pp. 1394-1403 ◽  
Author(s):  
Steven Daniel Funk ◽  
Arif Yurdagul ◽  
Jonette M. Green ◽  
Krishna A. Jhaveri ◽  
Martin Alexander Schwartz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Specific Protein ◽  
Kinase Activation ◽  
P21 Activated Kinase ◽  
Kinase A ◽  
Specific Protein Kinase

scholarly journals Nitric Oxide Modulates Cardiac Na + Channel via Protein Kinase A and Protein Kinase G

2001 ◽  
Vol 89 (11) ◽  
pp. 1005-1013 ◽  
Author(s):  
Gias U. Ahmmed ◽  
Yanfang Xu ◽  
Pei Hong Dong ◽  
Zhao Zhang ◽  
Jason Eiserich ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein Kinase G ◽  
Na Channel ◽  
Kinase A

scholarly journals  -Cell-Specific Protein Kinase A Activation Enhances the Efficiency of Glucose Control by Increasing Acute-Phase Insulin Secretion

Diabetes ◽  
2013 ◽  
Vol 62 (5) ◽  
pp. 1527-1536 ◽  
Author(s):  
K. A. Kaihara ◽  
L. M. Dickson ◽  
D. A. Jacobson ◽  
N. Tamarina ◽  
M. W. Roe ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Acute Phase ◽  
Glucose Control ◽  
Specific Protein ◽  
Kinase A ◽  
Specific Protein Kinase

scholarly journals Soluble Guanylate Cyclase as a Novel Treatment Target for Osteoporosis

Endocrinology ◽  
2014 ◽  
Vol 155 (12) ◽  
pp. 4720-4730 ◽  
Author(s):  
Jisha Joshua ◽  
Gerburg K. Schwaerzer ◽  
Hema Kalyanaraman ◽  
Esther Cory ◽  
Robert L. Sah ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Bone Microarchitecture ◽  
Protein Kinase G ◽  
Protective Effects ◽  
Major Health Problem ◽  
Ovariectomized Mice ◽  
17Β Estradiol

Osteoporosis is a major health problem leading to fractures that cause substantial morbidity and mortality. Current osteoporosis therapies have significant drawbacks, creating a need for novel bone-anabolic agents. We previously showed that the nitric oxide/cyclic GMP (cGMP)/protein kinase G pathway mediates some of the anabolic effects of estrogens and mechanical stimulation in osteoblasts and osteocytes, leading us to hypothesize that cGMP-elevating agents may have bone-protective effects. We tested cinaciguat, a prototype of a novel class of soluble guanylate cyclase activators, in a mouse model of estrogen deficiency-induced osteoporosis. Compared with sham-operated mice, ovariectomized mice had lower serum cGMP concentrations, which were largely restored to normal by treatment with cinaciguat or low-dose 17β-estradiol. Microcomputed tomography of tibiae showed that cinaciguat significantly improved trabecular bone microarchitecture in ovariectomized animals, with effect sizes similar to those obtained with estrogen replacement therapy. Cinaciguat reversed ovariectomy-induced osteocyte apoptosis as efficiently as estradiol and enhanced bone formation parameters in vivo, consistent with in vitro effects on osteoblast proliferation, differentiation, and survival. Compared with 17β-estradiol, which completely reversed the ovariectomy-induced increase in osteoclast number, cinaciguat had little effect on osteoclasts. Direct guanylate cyclase stimulators have been extremely well tolerated in clinical trials of cardiovascular diseases, and our findings provide proof-of-concept for this new class of drugs as a novel, anabolic treatment strategy for postmenopausal osteoporosis, confirming an important role of nitric oxide/cGMP/protein kinase G signaling in bone.

Nitric oxide attenuates H2O2-induced endothelial barrier dysfunction: mechanisms of protection

2001 ◽  
Vol 280 (1) ◽  
pp. L116-L126 ◽  
Author(s):  
Mahesh P. Gupta ◽  
Michael D. Ober ◽  
Carolyn Patterson ◽  
Mohammed Al-Hassani ◽  
Viswanathan Natarajan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Barrier Function ◽  
Soluble Guanylate Cyclase ◽  
Endothelial Barrier ◽  
Barrier Dysfunction ◽  
Endothelial Barrier Dysfunction ◽  
Signaling Mechanisms ◽  
Kinase A

Nitric oxide (·NO) attenuates hydrogen peroxide (H2O2)-mediated injury in porcine pulmonary artery endothelial cells (PAECs) and modulates intracellular levels of cGMP and cAMP. We hypothesized that ·NO attenuates H2O2-induced PAEC monolayer barrier dysfunction through cyclic nucleotide-dependent signaling mechanisms. To examine this hypothesis, cultured PAEC monolayers were treated with H2O2, and barrier function was measured as transmonolayer albumin clearance. H2O2caused significant PAEC barrier dysfunction that was attenuated by intracellular as well as extracellular ·NO generation. ·NO increased PAEC cGMP and cAMP levels, but treatment with inhibitors of soluble guanylate cyclase or protein kinase G did not abrogate ·NO-mediated barrier protection. In contrast, H2O2decreased protein kinase A activity, and inhibiting protein kinase A abrogated the protective effect of ·NO. H2O2-induced barrier dysfunction was not associated with decreased levels of cGMP or cAMP. 3-Isobutyl-1-methylxanthine and the cGMP analog 8-bromo-cGMP had little effect on H2O2-mediated endothelial barrier dysfunction, whereas 8-bromo-cAMP plus 3-isobutyl-1-methylxanthine was protective. These results indicate that ·NO modulates vascular endothelial barrier function through cAMP-dependent signaling mechanisms.

scholarly journals Regulation of Sertoli Cell Tight Junction Dynamics in the Rat Testis via the Nitric Oxide Synthase/Soluble Guanylate Cyclase/3′,5′-Cyclic Guanosine Monophosphate/Protein Kinase G Signaling Pathway: an in Vitro Study

Endocrinology ◽  
2003 ◽  
Vol 144 (7) ◽  
pp. 3114-3129 ◽  
Author(s):  
Nikki P. Y. Lee ◽  
C. Yan Cheng
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Tight Junction ◽  
Sertoli Cell ◽  
Guanylate Cyclase ◽  
Barrier Function ◽  
Soluble Guanylate Cyclase ◽  
Protein Kinase G ◽  
Camp And Cgmp

Abstract Nitric oxide (NO) synthase (NOS) catalyzes the oxidation of l-arginine to NO. NO plays a crucial role in regulating various physiological functions, possibly including junction dynamics via its effects on cAMP and cGMP, which are known modulators of tight junction (TJ) dynamics. Although inducible NOS (iNOS) and endothelial NOS (eNOS) are found in the testis and have been implicated in the regulation of spermatogenesis, their role(s) in TJ dynamics, if any, is not known. When Sertoli cells were cultured at 0.5–1.2 × 106 cells/cm2 on Matrigel-coated dishes or bicameral units, functional TJ barrier was formed when the barrier function was assessed by quantifying transepithelial electrical resistance across the cell epithelium. The assembly of the TJ barrier was shown to associate with a significant plummeting in the levels of iNOS and eNOS, seemingly suggesting that their presence by producing NO might perturb TJ assembly. To further confirm the role of NOS on the TJ barrier function in vitro, zinc (II) protoporphyrin-IX (ZnPP), an NOS inhibitor and a soluble guanylate cyclase inhibitor, was added to the Sertoli cell cultures during TJ assembly. Indeed, ZnPP was found to facilitate the assembly and maintenance of the Sertoli cell TJ barrier, possibly by inducing the production of TJ-associated proteins, such as occludin. Subsequent studies by immunoprecipitation and immunoblotting have shown that iNOS and eNOS are structurally linked to TJ-integral membrane proteins, such as occludin, and cytoskeletal proteins, such as actin, vimentin, and α-tubulin. When the cAMP and cGMP levels in these ZnPP-treated samples were quantified, a ZnPP-induced reduction of intracellular cGMP, but not cAMP, was indeed detected. Furthermore, 8-bromo-cGMP, a cell membrane-permeable analog of cGMP, could also perturb the TJ barrier dose dependently similar to the effects of 8-bromo-cAMP. KT-5823, a specific inhibitor of protein kinase G, was shown to facilitate the Sertoli cell TJ barrier assembly. Cytokines, such as TGF-β and TNF-α, known to perturb the Sertoli cell TJ barrier, were also shown to stimulate Sertoli cell iNOS and eNOS expression dose dependently in vitro. Collectively, these results illustrate NOS is an important physiological regulator of TJ dynamics in the testis, exerting its effects via the NO/soluble guanylate cyclase/cGMP/protein kinase G signaling pathway.

scholarly journals Roles for soluble guanylate cyclase and a thiol oxidation-elicited subunit dimerization of protein kinase G in pulmonary artery relaxation to hydrogen peroxide

2010 ◽  
Vol 299 (4) ◽  
pp. H1235-H1241 ◽  
Author(s):  
Boon Hwa Neo ◽  
Sharath Kandhi ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Protein Kinase ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Protein Kinase G ◽  
Thiol Oxidation ◽  
Organoid Culture ◽  
Vasp Phosphorylation

We have previously provided evidence that hydrogen peroxide (H2O2) stimulates soluble guanylate cyclase (sGC) under conditions where it relaxes isolated endothelium-removed bovine pulmonary arteries (BPAs). Since it was recently reported that H2O2 induces coronary vasorelaxation associated with a nitric oxide/cGMP-independent thiol oxidation/subunit dimerization-elicited activation of protein kinase G (PKG), we investigated whether this mechanism participates in the relaxation of BPAs to H2O2. BPAs precontracted with serotonin (incubated under hypoxia to lower endogenous H2O2) were exposed to increasing concentrations of H2O2. It was observed that 0.1–1 mM H2O2 caused increased PKG dimerization and relaxation. These responses were associated with increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at the serine-239 site known to be mediated by PKG. Treatment of BPAs with 1 mM DTT attenuated PKG dimerization, VASP phosphorylation, and relaxation to H2O2. An organoid culture of BPAs for 48 h with 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a heme oxidant inhibitor of sGC activation, depleted sGC expression by 85%, associated with a 67% attenuation of VASP phosphorylation and 48% inhibition of relaxation elicited by 100 μM H2O2. Thus both a sGC activation/cGMP-dependent and a thiol oxidation subunit dimerization/cGMP-independent activation of PKG appear to contribute to the relaxation of BPAs elicited by H2O2.

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