Role of Renin-Angiotensin System in Phospholipase C-Mediated Signaling in Congestive Heart Failure

Author(s):  
Paramjit S. Tappia ◽  
Nina Aroutiounova ◽  
Naranjan S. Dhalla
1984 ◽  
Vol 53 (4) ◽  
pp. 614-618 ◽  
Author(s):  
Günter A.J. Riegger ◽  
Gerhart Liebau ◽  
Matthias Holzschuh ◽  
Dorothea Witkowski ◽  
Hansgeorg Steilner ◽  
...  

1990 ◽  
Vol 66 (11) ◽  
pp. D22-D32 ◽  
Author(s):  
Alan T. Hirsch ◽  
Yigal M. Pinto ◽  
Heribert Schunkert ◽  
Victor J. Dzau

2017 ◽  
Vol 312 (5) ◽  
pp. H968-H979 ◽  
Author(s):  
Neeru M. Sharma ◽  
Shyam S. Nandi ◽  
Hong Zheng ◽  
Paras K. Mishra ◽  
Kaushik P. Patel

An activated renin-angiotensin system (RAS) within the central nervous system has been implicated in sympathoexcitation during various disease conditions including congestive heart failure (CHF). In particular, activation of the RAS in the paraventricular nucleus (PVN) of the hypothalamus has been recognized to augment sympathoexcitation in CHF. We observed a 2.6-fold increase in angiotensinogen (AGT) in the PVN of CHF. To elucidate the molecular mechanism for increased expression of AGT, we performed in silico analysis of the 3′-untranslated region (3′-UTR) of AGT and found a potential binding site for microRNA (miR)-133a. We hypothesized that decreased miR-133a might contribute to increased AGT in the PVN of CHF rats. Overexpression of miR-133a in NG108 cells resulted in 1.4- and 1.5-fold decreases in AGT and angiotensin type II (ANG II) type 1 receptor (AT1R) mRNA levels, respectively. A luciferase reporter assay performed on NG108 cells confirmed miR-133a binding to the 3′-UTR of AGT. Consistent with these in vitro data, we observed a 1.9-fold decrease in miR-133a expression with a concomitant increase in AGT and AT1R expression within the PVN of CHF rats. Furthermore, restoring the levels of miR-133a within the PVN of CHF rats with viral transduction resulted in a significant reduction of AGT (1.4-fold) and AT1R (1.5-fold) levels with a concomitant decrease in basal renal sympathetic nerve activity (RSNA). Restoration of miR-133a also abrogated the enhanced RSNA responses to microinjected ANG II within the PVN of CHF rats. These results reveal a novel and potentially unique role for miR-133a in the regulation of ANG II within the PVN of CHF rats, which may potentially contribute to the commonly observed sympathoexcitation in CHF. NEW & NOTEWORTHY Angiotensinogen (AGT) expression is upregulated in the paraventricular nucleus of the hypothalamus through posttranscriptional mechanism interceded by microRNA-133a in heart failure. Understanding the mechanism of increased expression of AGT in pathological conditions leading to increased sympathoexcitation may provide the basis for the possible development of new therapeutic agents with enhanced specificity.


1983 ◽  
Vol 75 (3) ◽  
pp. 445-447 ◽  
Author(s):  
Andrew B. Covit ◽  
Gary L. Schaer ◽  
Jean E. Sealey ◽  
John H. Laragh ◽  
Robert J. Cody

2008 ◽  
Vol 294 (1) ◽  
pp. R26-R32 ◽  
Author(s):  
J. C. B. Ferreira ◽  
A. V. Bacurau ◽  
F. S. Evangelista ◽  
M. A. Coelho ◽  
E. M. Oliveira ◽  
...  

Sympathetic hyperactivity (SH) and renin angiotensin system (RAS) activation are commonly associated with heart failure (HF), even though the relative contribution of these factors to the cardiac derangement is less understood. The role of SH on RAS components and its consequences for the HF were investigated in mice lacking α2A and α2C adrenoceptor knockout (α2A/α2CARKO) that present SH with evidence of HF by 7 mo of age. Cardiac and systemic RAS components and plasma norepinephrine (PN) levels were evaluated in male adult mice at 3 and 7 mo of age. In addition, cardiac morphometric analysis, collagen content, exercise tolerance, and hemodynamic assessments were made. At 3 mo, α2A/α2CARKO mice showed no signs of HF, while displaying elevated PN, activation of local and systemic RAS components, and increased cardiomyocyte width (16%) compared with wild-type mice (WT). In contrast, at 7 mo, α2A/α2CARKO mice presented clear signs of HF accompanied only by cardiac activation of angiotensinogen and ANG II levels and increased collagen content (twofold). Consistent with this local activation of RAS, 8 wk of ANG II AT1 receptor blocker treatment restored cardiac structure and function comparable to the WT. Collectively, these data provide direct evidence that cardiac RAS activation plays a major role underlying the structural and functional abnormalities associated with a genetic SH-induced HF in mice.


2006 ◽  
Vol 111 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Frederic Lefebvre ◽  
Annick Préfontaine ◽  
Angelino Calderone ◽  
Alexandre Caron ◽  
Jean-François Jasmin ◽  
...  

Lung structural remodelling, characterized by myofibroblast proliferation and collagen deposition, contributes to impaired functional capacity in CHF (congestive heart failure). As the lung is the primary site for the formation of Ang II (angiotensin II), local modifications of this system could contribute to lung remodelling. Rats with CHF, induced following myocardial infarction (MI) via coronary artery ligation, were compared with sham-operated controls. The MI group developed lung remodelling as confirmed by morphometric measurements and immunohistochemistry. Pulmonary Ang II concentrations increased more than 6-fold (P<0.01), and AT1 (Ang II type 1) receptor expression was elevated by 3-fold (P<0.01) with evidence of distribution in myofibroblasts. AT2 (Ang II type 2) receptor expression was unchanged. In isolated lung myofibroblasts, AT1 and AT2 receptors were expressed, and Ang II stimulated proliferation as measured by [3H]thymidine incorporation. In normal rats, chronic intravenous infusion of Ang II (0.5 mg·kg−1 of body weight·day−1) for 28 days significantly increased mean arterial pressure (P<0.05), without pulmonary hypertension, lung remodelling or a change in AT1 receptor expression. We conclude that there is a modification of the pulmonary renin–angiotensin system in CHF, with increased Ang II levels and AT1 receptor expression on myofibroblasts. Although this may contribute to lung remodelling, the lack of effect of increased plasma Ang II levels alone suggests the importance of local pulmonary Ang II levels combined with the effect of other factors activated in CHF.


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