Abstract 189: Natriuretic Peptide Receptor-A Regulates Angiotensin-II Mediated NF-κB Via Mkp-1 Dependent Pathway

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Gopi Venkatachalam ◽  
Umadevi Subramanian ◽  
Parthasarathy Arumugam ◽  
Elangovan Vellaichamy
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Natriuretic Peptide ◽  
Nuclear Translocation ◽  
Heart Tissue ◽  
Male Rats ◽  
Natriuretic Peptide Receptor ◽  
Ang Ii ◽  
Hypertrophic Growth ◽  
Peptide Receptor

Atrial natriuretic peptide (ANP) exerts local anti-hypertrophic activity in heart tissue by binding to natriuretic peptide receptor (NPR)-A. However, patients with cardiac hypertrophy and congestive heart failure have elevated plasma and tissue levels of ANP and brain natriuretic peptide (BNP) along with Angiotensin II (Ang II). However, the rationale behind the impaired action of ANP in diseased state is not well understood. In this study, we sought to examine the signaling mechanism by which Ang II modulates local anti-hypertrophic effect through inhibition of Npr1 gene, which codes for NPR-A, in the heart. Hence, in vivo , Wistar male rats (n=8/group) were administered suppressor dose of Ang II (50ng/kg/min) for 14 days through implanted mini-osmotic pumps. Also, in vitro , H9C2 (2-1) cardio myofibroblast cells were exposed to Ang II (10 -7 M) for 20 hours. Upon treatment with Ang II, the mRNA and protein expression of Npr1 (p<0.01) was decreased with significant increase in expression of AT1R (p<0.01) in the heart tissues. In addition, a concomitant decrease in cGMP activity and production in isolated heart tissue membrane preparation was found in Ang II infused rats. Moreover, Ang II infusion causes a suppression of MKP-1 phosphatase; while enhancing the phosphorylation of ERK1/2 (p<0.01) and NF-κB (p<0.01) proteins. Similarly, H9C2 cells exhibited the hypertrophic growth with increased expression of AT1R and activation of ERK1/2 proteins on stimulation with Ang II. Furthermore, gene silencing using siRNA-NPR-A prior to Ang II treatment augmented the translocation of NF-κB and activation of ERK1/2 (3-fold). Whereas, pre-treatment with losartan or cGMP analog 8-Br-cGMP, an activator of cGMP-dependent protein kinases, abolished the stimulatory effects of Ang II on AT1R, NF-κB nuclear translocation and phosphorylation of MAPK, but activated the MKP-1 phosphatase. These results suggest that NPRA-cGMP signaling exerts inhibitory effects on Ang II by antagonizing the upstream signaling pathways and by activation of MKP-1 to counter-regulate NF-κB and MAPKs through cGMP dependent mechanism; thereby mediate local anti-hypertrophic activity in cardiac hypertrophy.

scholarly journals Renal Natriuretic Peptide Receptor-C Deficiency Attenuates NaCl Cotransporter Activity in Angiotensin II–Induced Hypertension

Hypertension ◽  
2021 ◽  
Vol 77 (3) ◽  
pp. 868-881
Author(s):  
Shuai Shao ◽  
Xiao-Dong Li ◽  
Yuan-Yuan Lu ◽  
Shi-Jin Li ◽  
Xiao-Hui Chen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Natriuretic Peptide ◽  
Elevated Blood Pressure ◽  
Natriuretic Peptide Receptor ◽  
Sodium Retention ◽  
Ang Ii ◽  
Elevated Blood ◽  
Peptide Receptor ◽  
Induced Hypertension

Genome-wide association studies have identified that NPR-C (natriuretic peptide receptor-C) variants are associated with elevation of blood pressure. However, the mechanism underlying the relationship between NPR-C and blood pressure regulation remains elusive. Here, we investigate whether NPR-C regulates Ang II (angiotensin II)-induced hypertension through sodium transporters activity. Wild-type mice responded to continuous Ang II infusion with an increased renal NPR-C expression. Global NPR-C deficiency attenuated Ang II–induced increased blood pressure both in male and female mice associated with more diuretic and natriuretic responses to a saline challenge. Interestingly, Ang II increased both total and phosphorylation of NCC (NaCl cotransporter) abundance involving in activation of WNK4 (with-no-lysine kinase 4)/SPAK (Ste20-related proline/alanine-rich kinase) which was blunted by NPR-C deletion. NCC inhibitor, hydrochlorothiazide, failed to induce natriuresis in NPR-C knockout mice. Moreover, low-salt and high-salt diets–induced changes of total and phosphorylation of NCC expression were normalized by NPR-C deletion. Importantly, tubule-specific deletion of NPR-C also attenuated Ang II–induced elevated blood pressure, total and phosphorylation of NCC expression. Mechanistically, in distal convoluted tubule cells, Ang II dose and time-dependently upregulated WNK4/SPAK/NCC kinase pathway and NPR-C/Gi/PLC/PKC signaling pathway mediated NCC activation. These results demonstrate that NPR-C signaling regulates NCC function contributing to sodium retention-mediated elevated blood pressure, which suggests that NPR-C is a promising candidate for the treatment of sodium retention-related hypertension.

Genetic disruption of atrial natriuretic peptide receptor-A alters renin and angiotensin II levels

2001 ◽  
Vol 281 (4) ◽  
pp. F665-F673 ◽  
Author(s):  
Shang-Jin Shi ◽  
Huong T. Nguyen ◽  
Guru Dutt Sharma ◽  
L. Gabriel Navar ◽  
Kailash N. Pandey
Keyword(s):  
Natriuretic Peptide ◽  
Systolic Arterial Pressure ◽  
Inhibitory Response ◽  
Mutant Mice ◽  
Natriuretic Peptide Receptor ◽  
Ang Ii ◽  
Wild Type ◽  
Compensatory Response ◽  
Peptide Receptor ◽  
Natriuretic Peptide Receptor A

We have studied cardiovascular and renal phenotypes in Npr1 (genetic determinant of natriuretic peptide receptor-A; NPRA) gene-disrupted mutant mouse model. The baseline systolic arterial pressure (SAP) in 0-copy mutant (−/−) mice (143 ± 2 mmHg) was significantly higher than in 2-copy wild-type (+/+) animals (104 ± 2 mmHg); however, the SAP in 1-copy heterozygotes (+/−) was at an intermediate value (120 ± 4 mmHg). To determine whether Npr1 gene function affects the renin-angiotensin-aldosterone system (RAAS), we measured the components of RAAS in plasma, kidney, and adrenal gland of 0-copy, 1-copy, and 2-copy male mice. Newborn (2 days after the birth) 0-copy pups showed 2.5-fold higher intrarenal renin contents compared with 2-copy wild-type counterparts (0-copy 72 ± 12 vs. 2-copy 30 ± 7 μg ANG I · mg protein−1 · h−1, respectively). The intrarenal ANG II level in 0-copy pups was also higher than in 2-copy controls (0-copy 33 ± 5 vs. 2-copy 20 ± 2 pg/mg protein, respectively). However, both young (3 wk) and adult (16 wk) 0-copy mutant mice showed a dramatic 50–80% reduction in plasma renin concentrations (PRCs) and in expression of renal renin message compared with 2-copy control animals. In contrast, the adrenal renin content and mRNA expression levels were 1.5- to 2-fold higher in 0-copy adult mice than in 2-copy animals. The results suggest that inhibition of renal and systemic RAAS is a compensatory response that prevents greater increases in elevated arterial pressures in adult NPRA null mutant mice. However, the greater renin and ANG II levels seen in 0-copy newborn pups provide evidence that the direct effect of NPRA activation on renin is an inhibitory response.

scholarly journals Deficiency of T-type Ca2+ channels Cav3.1 and Cav3.2 has no effect on angiotensin II-induced hypertension but differential effect on plasma aldosterone in mice

2019 ◽  
Vol 317 (2) ◽  
pp. F254-F263
Author(s):  
Anne D. Thuesen ◽  
Stine H. Finsen ◽  
Louise L. Rasmussen ◽  
Ditte C. Andersen ◽  
Boye L. Jensen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Natriuretic Peptide ◽  
Mineralocorticoid Receptor ◽  
Plasma Aldosterone ◽  
Receptor Blocker ◽  
Ang Ii ◽  
Induced Hypertension

T-type Ca2+ channel Cav3.1 promotes microvessel contraction ex vivo. It was hypothesized that in vivo, functional deletion of Cav3.1, but not Cav3.2, protects mice against angiotensin II (ANG II)-induced hypertension. Mean arterial blood pressure (MAP) and heart rate were measured continuously with chronically indwelling catheters during infusion of ANG II (30 ng·kg−1·min−1, 7 days) in wild-type (WT), Cav3.1−/−, and Cav3.2−/− mice. Plasma aldosterone and renin concentrations were measured by radioimmunoassays. In a separate series, WT mice were infused with ANG II (100 ng·kg−1·min−1) with and without the mineralocorticoid receptor blocker canrenoate. Cav3.1−/− and Cav3.2−/− mice exhibited no baseline difference in MAP compared with WT mice, but day-night variation was blunted in both Cav3.1 and Cav3.2−/− mice. ANG II increased significantly MAP in WT, Cav3.1−/−, and Cav3.2−/− mice with no differences between genotypes. Heart rate was significantly lower in Cav3.1−/− and Cav3.2−/− mice compared with control mice. After ANG II infusion, plasma aldosterone concentration was significantly lower in Cav3.1−/− compared with Cav3.2−/− mice. In response to ANG II, fibrosis was observed in heart sections from both WT and Cav3.1−/− mice and while cardiac atrial natriuretic peptide mRNA was similar, the brain natriuretic peptide mRNA increase was mitigated in Cav3.1−/− mice ANG II at 100 ng/kg yielded elevated pressure and an increased heart weight-to-body weight ratio in WT mice. Cardiac hypertrophy, but not hypertension, was prevented by the mineralocorticoid receptor blocker canrenoate. In conclusion, T-type channels Cav3.1and Cav3.2 do not contribute to baseline blood pressure levels and ANG II-induced hypertension. Cav3.1, but not Cav3.2, contributes to aldosterone secretion. Aldosterone promotes cardiac hypertrophy during hypertension.

Effects of triiodo-thyronine on angiotensin-induced cardiomyocyte hypertrophy: reversal of increased β-myosin heavy chain gene expression

2006 ◽  
Vol 84 (8-9) ◽  
pp. 935-941 ◽  
Author(s):  
Baohua Wang ◽  
Jingping Ouyang ◽  
Zhengyuan Xia
Keyword(s):  
Gene Expression ◽  
Angiotensin Ii ◽  
Thyroid Hormone ◽  
Cardiac Hypertrophy ◽  
Atpase Activity ◽  
Mrna Expression ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Ang Ii ◽  
Hypertrophic Growth

Thyroid hormone-induced cardiac hypertrophy is similar to that observed in physiological hypertrophy, which is associated with high cardiac contractility and increased α-myosin heavy chain (α-MHC, the high ATPase activity isoform) expression. In contrast, angiotensin II (Ang II) induces an increase in myocardial mass with a compromised contractility accompanied by a shift from α-MHC to the fetal isoform β-MHC (the low ATPase activity isoform), which is considered as a pathological hypertrophy and inevitably leads to the development of heart failure. The present study is designed to assess the effect of thyroid hormone on angiotensin II-induced hypertrophic growth of cardiomyocytes in vitro. Cardiomyocytes were prepared from hearts of neonatal Wistar rats. The effects of Ang II and 3,3′,5-triiodo-thyronine (T3) on incorporations of [3H]-thymine and [3H]-leucine, MHC isoform mRNA expression, PKC activity, and PKC isoform protein expression were studied. Ang II enhanced [3H]-leucine incorporation, β-MHC mRNA expression, PKC activity, and PKCε expression and inhibited α-MHC mRNA expression in cardiomyocytes. T3 treatment prevented Ang II-induced increases in PKC activity, PKCε, and β-MHC mRNA overexpression and favored α-MHC mRNA expression. Thyroid hormone appears to be able to reprogram gene expression in Ang II-induced cardiac hypertrophy, and a PKC signal pathway may be involved in such remodeling process.

scholarly journals Natriuretic Peptide Receptor-C Mitigates Angiotensin II Induced Fibrosis in the Atria and Sinoatrial Node

2020 ◽  
Vol 118 (3) ◽  
pp. 571a
Author(s):  
Martin Mackasey ◽  
Hailey J. Jansen ◽  
Motahareh Moghtadaei ◽  
Robert A. Rose
Keyword(s):  
Angiotensin Ii ◽  
Natriuretic Peptide ◽  
Sinoatrial Node ◽  
Natriuretic Peptide Receptor ◽  
Peptide Receptor

scholarly journals Atrial secretion of ANP is suppressed in renovascular hypertension: shifting of ANP secretion from atria to the left ventricle

2018 ◽  
Vol 315 (3) ◽  
pp. H590-H601 ◽  
Author(s):  
Rui Tan ◽  
You Mee Ahn ◽  
Hye Yoom Kim ◽  
Yun Jung Lee ◽  
Kyung Woo Cho ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Left Ventricle ◽  
Signaling Pathway ◽  
Renovascular Hypertension ◽  
Natriuretic Peptide ◽  
Mrna Levels ◽  
Natriuretic Peptide Receptor ◽  
Hypertensive Rats ◽  
Major Site ◽  
Peptide Receptor

In the present study, the change in secretion of atrial natriuretic peptide (ANP) from the atria was defined in hypertension accompanied by ventricular hypertrophy and increased synthesis of ANP. To identify the change of the secretion and mechanisms involved, experiments were performed in isolated perfused beating atria from sham-operated normotensive and renovascular hypertensive rats. Expression of ANP, natriuretic peptide receptor (NPR)-C, components of the renin-angiotensin system, and muscarinic signaling pathway was measured in cardiac tissues. Basal levels of ANP secretion and acetylcholine (ACh)- and stretch-induced activation of ANP secretion were suppressed in the atria from hypertensive compared with normotensive rats. ACh increased ANP secretion via M2 muscarinic ACh receptor-ACh-sensitive K+ channel signaling. In hypertensive rats, ANP concentration increased in the left ventricle but decreased in the right ventricle. The atrial concentration of ANP was not changed in hypertensive compared with normotensive rats. ANP mRNA expression was accentuated in the left ventricle but suppressed in the other cardiac chambers in the hearts of hypertensive rats. NPR-C expression was inversely related to ANP mRNA levels. Angiotensin II type 1 receptor (AT1R) expression was accentuated in the cardiac chambers from hypertensive rats compared with normotensive rats, whereas angiotensin II type 2 receptor, M2 muscarinic receptor, and Kir3.4 channels were suppressed. AT1R blockade with losartan reversed the change observed in hypertensive rats. The present findings indicate that renovascular hypertension shifts the major site of ANP secretion and synthesis from the atria to the left ventricle through modulation of the expression of ANP, NPR-C, AT1R, and the M2 muscarinic signaling pathway. NEW & NOTEWORTHY Renovascular hypertension suppresses the atrial secretion of ANP and shifts the major site of the regulation of ANP secretion and synthesis from atria to the hypertrophied left ventricle possibly via modulation of the expression of ANP, natriuretic peptide receptor-C, angiotensin II subtype 1 receptor, and M2 muscarinic signaling pathway.

Sign in / Sign up

Export Citation Format

Share Document