Functional Analysis of Tissue Renin-Angiotensin System Using “Gain and Loss of Function” Approaches: In Vivo Test of in Vitro Hypothesis

Cancer stem cells (CSCs) drive metastasis, treatment resistance, and tumor recurrence. CSCs reside within a niche, an anatomically distinct site within the tumor microenvironment (TME) that consists of malignant and non-malignant cells, including immune cells. The renin–angiotensin system (RAS), a critical regulator of stem cells and key developmental processes, plays a vital role in the TME. Non-malignant cells within the CSC niche and stem cell signaling pathways such as the Wnt, Hedgehog, and Notch pathways influence CSCs. Components of the RAS and cathepsins B and D that constitute bypass loops of the RAS are expressed on CSCs in many cancer types. There is extensive in vitro and in vivo evidence showing that RAS inhibition reduces tumor growth, cell proliferation, invasion, and metastasis. However, there is inconsistent epidemiological data on the effect of RAS inhibitors on cancer incidence and survival outcomes, attributed to different patient characteristics and methodologies used between studies. Further mechanistic studies are warranted to investigate the precise effects of the RAS on CSCs directly and/or the CSC niche. Targeting the RAS, its bypass loops, and convergent signaling pathways participating in the TME and other key stem cell pathways that regulate CSCs may be a novel approach to cancer treatment:

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Galectin-7 Impairs Placentation and Causes Preeclampsia Features in Mice

Hypertension ◽

10.1161/hypertensionaha.120.15313 ◽

2020 ◽

Vol 76 (4) ◽

pp. 1185-1194 ◽

Cited By ~ 1

Author(s):

Ellen Menkhorst ◽

Wei Zhou ◽

Leilani L. Santos ◽

Sarah Delforce ◽

Teresa So ◽

...

Keyword(s):

Renin Angiotensin System ◽

First Trimester ◽

Angiotensin System ◽

Renin Angiotensin ◽

Elevated Systolic Blood Pressure ◽

System Components ◽

Pregnant Mice ◽

New Treatment

Preeclampsia is a serious pregnancy-induced disorder unique to humans. The etiology of preeclampsia is poorly understood; however, poor placental formation is thought causal. Galectin-7 is produced by trophoblast and is elevated in first-trimester serum of women who subsequently develop preeclampsia. We hypothesized that elevated placental galectin-7 may be causative of preeclampsia. Here, we demonstrated increased galectin-7 production in chorionic villous samples from women who subsequently develop preterm preeclampsia compared with uncomplicated pregnancies. In vitro, galectin-7 impaired human first-trimester trophoblast outgrowth, increased placental production of the antiangiogenic sFlt-1 splice variant, sFlt-1-e15a , and reduced placental production and secretion of ADAM12 (a disintegrin and metalloproteinase12) and angiotensinogen. In vivo, galectin-7 administration (E8–E12) to pregnant mice caused elevated systolic blood pressure, albuminuria, impaired placentation (reduced labyrinth vascular branching, impaired decidual spiral artery remodeling, and a proinflammatory placental state demonstrated by elevated IL1β, IL6 and reduced IL10), and dysregulated expression of renin-angiotensin system components in the placenta, decidua, and kidney, including angiotensinogen, prorenin, and the angiotensin II type 1 receptor. Collectively, this study demonstrates that elevated galectin-7 during placental formation contributes to abnormal placentation and suggests that it leads to the development of preeclampsia via altering placental production of sFlt-1 and renin-angiotensin system components. Targeting galectin-7 may be a new treatment option for preeclampsia.

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Impact of diminazene aceturate on renin-angiotensin system, infectious myocarditis and skeletal myositis in mice: An in vitro and in vivo study

Life Sciences ◽

10.1016/j.lfs.2020.118067 ◽

2020 ◽

Vol 257 ◽

pp. 118067

Author(s):

Thaiany G. Souza-Silva ◽

Diego F. Vilas-Boas ◽

Elda Gonçalves-Santos ◽

Ana Lia Mazzeti ◽

Ivo S. Caldas ◽

...

Keyword(s):

Renin Angiotensin System ◽

In Vivo Study ◽

Diminazene Aceturate ◽

Angiotensin System ◽

Renin Angiotensin

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ANG II reduces net acid secretion in rat outer medullary collecting duct

AJP Renal Physiology ◽

10.1152/ajprenal.00400.2002 ◽

2003 ◽

Vol 285 (5) ◽

pp. F930-F937 ◽

Cited By ~ 14

Author(s):

Susan M. Wall ◽

Michael P. Fischer ◽

Dawn M. Glapion ◽

Mae De La Calzada

Keyword(s):

Acid Secretion ◽

Collecting Duct ◽

Renin Angiotensin System ◽

Ang Ii ◽

Acid Base Balance ◽

Angiotensin System ◽

Renin Angiotensin ◽

Medullary Collecting Duct

In rat outer medullary collecting duct (OMCD), the mechanism(s) and regulation of H+ secretion are not understood fully. The effect of changes in acid-base balance and the renin-angiotensin system on net H+ secretion was explored. Rats received NaCl, NaHCO3, NH4Cl, or nothing in their drinking water for 7 days. Total ammonia and total CO2 ( JtCO2) fluxes were measured in OMCD tubules perfused in vitro from rats in each treatment group. JtCO2 was reduced in tubules from rats drinking NH4Cl relative to those drinking NaHCO3. Because NH4Cl intake increases plasma renin and aldosterone, we asked if upregulation of the renin-angiotensin system reduces net H+ secretion. Deoxycorticosterone pivalate administered in vivo did not affect JtCO2. However, ANG II given in vivo at 0.1 ng/min reduced JtCO2 by 35%. To determine if ANG II has a direct effect on acid secretion, JtCO2 was measured with ANG II applied in vitro. ANG II (10-8 M) present in the bath solution reduced JtCO2 by 35%. This ANG II effect was not observed in the presence of the AT1 receptor blocker candesartan. In conclusion, in rat OMCD, JtCO2 is paradoxically reduced with NH4Cl ingestion. Increased circulating ANG II, as occurs during metabolic acidosis, reduces JtCO2.

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Upregulation of the vascular NAD(P)H-oxidase isoforms Nox1 and Nox4 by the renin-angiotensin system in vitro and in vivo

Free Radical Biology and Medicine ◽

10.1016/s0891-5849(01)00727-4 ◽

2001 ◽

Vol 31 (11) ◽

pp. 1456-1464 ◽

Cited By ~ 191

Author(s):

Kirstin Wingler ◽

Sandra Wünsch ◽

Reinhold Kreutz ◽

Lars Rothermund ◽

Martin Paul ◽

...

Keyword(s):

Renin Angiotensin System ◽

Angiotensin System ◽

Renin Angiotensin

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Functional Analysis of Cardiovascular Renin-Angiotensin System Using a Gain or Loss of Function Approach.

Hypertension Research ◽

10.1291/hypres.23.137 ◽

2000 ◽

Vol 23 (2) ◽

pp. 137-141 ◽

Cited By ~ 1

Author(s):

Ryuichi MORISHITA ◽

Motokuni AOKI ◽

Toshio OGIHARA

Keyword(s):

Functional Analysis ◽

Renin Angiotensin System ◽

Function Approach ◽

Loss Of Function ◽

Angiotensin System ◽

Renin Angiotensin

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Accelerated Repurposing and Drug Development of Pulmonary Hypertension Therapies for COVID-19 Treatment Using an AI-Integrated Biosimulation Platform

Molecules ◽

10.3390/molecules26071912 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1912

Author(s):

Kaushik Chakravarty ◽

Victor G. Antontsev ◽

Maksim Khotimchenko ◽

Nilesh Gupta ◽

Aditya Jagarapu ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Renin Angiotensin System ◽

Mechanistic Modeling ◽

Channel Blockers ◽

Angiotensin System ◽

In Silico Modeling ◽

Site Of Action ◽

Line Of Therapy

The COVID-19 pandemic has reached over 100 million worldwide. Due to the multi-targeted nature of the virus, it is clear that drugs providing anti-COVID-19 effects need to be developed at an accelerated rate, and a combinatorial approach may stand to be more successful than a single drug therapy. Among several targets and pathways that are under investigation, the renin-angiotensin system (RAS) and specifically angiotensin-converting enzyme (ACE), and Ca2+-mediated SARS-CoV-2 cellular entry and replication are noteworthy. A combination of ACE inhibitors and calcium channel blockers (CCBs), a critical line of therapy for pulmonary hypertension, has shown therapeutic relevance in COVID-19 when investigated independently. To that end, we conducted in silico modeling using BIOiSIM, an AI-integrated mechanistic modeling platform by utilizing known preclinical in vitro and in vivo datasets to accurately simulate systemic therapy disposition and site-of-action penetration of the CCBs and ACEi compounds to tissues implicated in COVID-19 pathogenesis.

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A novel role for miR-133a in centrally mediated activation of the renin-angiotensin system in congestive heart failure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00721.2016 ◽

2017 ◽

Vol 312 (5) ◽

pp. H968-H979 ◽

Cited By ~ 9

Author(s):

Neeru M. Sharma ◽

Shyam S. Nandi ◽

Hong Zheng ◽

Paras K. Mishra ◽

Kaushik P. Patel

Keyword(s):

Heart Failure ◽

Congestive Heart Failure ◽

Paraventricular Nucleus ◽

Renin Angiotensin System ◽

Luciferase Reporter ◽

Mrna Levels ◽

Ang Ii ◽

Angiotensin System ◽

Renin Angiotensin

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.

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Androgens augment proximal tubule transport

AJP Renal Physiology ◽

10.1152/ajprenal.00188.2003 ◽

2004 ◽

Vol 287 (3) ◽

pp. F452-F459 ◽

Cited By ~ 70

Author(s):

Albert Quan ◽

Sumana Chakravarty ◽

Jian-Kang Chen ◽

Jian-Chun Chen ◽

Samer Loleh ◽

...

Keyword(s):

Angiotensin Ii ◽

Proximal Tubule ◽

Specific Binding ◽

Extracellular Volume ◽

Renin Angiotensin System ◽

Angiotensin Receptors ◽

Sprague Dawley ◽

Angiotensin System ◽

Renin Angiotensin

The proximal tubule contains an autonomous renin-angiotensin system that regulates transport independently of circulating angiotensin II. Androgens are known to increase expression of angiotensinogen, but the effect of androgens on proximal tubule transport is unknown. In this in vivo microperfusion study, we examined the effect of androgens on proximal tubule transport. The volume reabsorptive rate in Sprague-Dawley rats given dihydrotestosterone (DHT) injections was significantly higher than in control rats given vehicle injections (4.57 ± 0.31 vs. 3.31 ± 0.23 nl·min−1·mm−1, P < 0.01). Luminally perfusing with either enalaprilat (10−4 M) to inhibit production of angiotensin II or losartan (10−8 M) to block the angiotensin receptor decreased the proximal tubule volume reabsorptive rate in DHT-treated rats to a significantly greater degree than in control vehicle-injected rats. The renal expression of angiotensinogen was shown to be higher in the DHT-treated animals, using Northern blot analysis. The expression of angiotensin receptors, determined by specific binding of angiotensin II, was not different in the two groups of animals. Brush-border membrane protein abundance of the Na/H exchanger, a membrane transport protein under angiotensin II regulation, was also higher in DHT-treated rats vs. control rats. Rats that received DHT had higher blood pressures than the control rats but had no change in their glomerular filtration rate. In addition, serum angiotensin II levels were lower in DHT-treated vs. control rats. These results suggest that androgens may directly upregulate the proximal tubule renin-angiotensin system, increase the volume reabsorptive rate, and thereby increase extracellular volume and blood pressure and secondarily decrease serum angiotensin II levels.

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