scholarly journals Renin Angiotensin System in Cognitive Function and Dementia

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Vijaya Lakshmi Bodiga ◽  
Sreedhar Bodiga
Keyword(s):  
Cognitive Function ◽  
Renin Angiotensin System ◽  
Organ Injury ◽  
Ang Ii ◽  
Microvascular Damage ◽  
Angiotensin System ◽  
Cerebrovascular Pathology ◽  
Beneficial Effects ◽  
Mas Receptor ◽  
End Stage

Angiotensin II represents a key molecule in hypertension and cerebrovascular pathology. By promoting inflammation and oxidative stress, enhanced Ang II levels accelerate the onset and progression of cell senescence. Sustained activation of RAS promotes end-stage organ injury associated with aging and results in cognitive impairment and dementia. The discovery of the angiotensin-converting enzyme ACE2-angiotensin (1–7)-Mas receptor axis that exerts vasodilator, antiproliferative, and antifibrotic actions opposed to those of the ACE-Ang II-AT1 receptor axis has led to the hypothesis that a decrease in the expression or activity of angiotensin (1–7) renders the systems more susceptible to the pathological actions of Ang II. Given the successful demonstration of beneficial effects of increased expression of ACE2/formation of Ang1–7/Mas receptor binding and modulation of Mas expression in animal models in containing cerebrovascular pathology in hypertensive conditions and aging, one could reasonably hope for analogous effects regarding the prevention of cognitive decline by protecting against hypertension and cerebral microvascular damage. Upregulation of ACE2 and increased balance of Ang 1–7/Ang II, along with positive modulation of Ang II signaling through AT2 receptors and Ang 1–7 signaling through Mas receptors, may be an appropriate strategy for improving cognitive function and treating dementia.

Brain angiotensin system: a new promise in the management of epilepsy?

2021 ◽  
Vol 135 (6) ◽  
pp. 725-730
Author(s):  
Alberto Javier Ramos
Keyword(s):  
Therapeutic Potential ◽  
Renin Angiotensin System ◽  
B Cell Lymphoma ◽  
Ang Ii ◽  
Angiotensin System ◽  
Beneficial Effects ◽  
System A ◽  
Pilocarpine Model ◽  
Animal Models Of Epilepsy ◽  
Future Work

Abstract Epilepsy is a highly prevalent neurological disease and anti-epileptic drugs (AED) are almost the unique clinical treatment option. A disbalanced brain renin–angiotensin system (RAS) has been proposed in epilepsy and several reports have shown that angiotensin II (Ang II) receptor-1 (ATR1) activation is pro-inflammatory and pro-epileptogenic. In agreement, ATR1 blockage with the repurposed drug losartan has shown benefits in animal models of epilepsy. Processing of Ang II by ACE2 enzyme renders Ang-(1-7), a metabolite that activates the mitochondrial assembly (Mas) receptor (MasR) pathway. MasR activation presents beneficial effects, facilitating vasodilatation, increasing anti-inflammatory and antioxidative responses. In a recent paper published in Clinical Science, Gomes and colleagues (Clin. Sci. (Lond.) (2020) 134, 2263–2277) performed intracerebroventricular (icv) infusion of Ang-(1-7) in animals subjected to the pilocarpine model of epilepsy, starting after the first spontaneous motor seizure (SMS). They showed that this approach reduced the frequency of SMS, restored animal anxiety, increased exploration, and augmented the hippocampal expression of protective catalase enzyme and antiapoptotic protein B-cell lymphoma 2 (Bcl-2). Interestingly, but surprisingly, Gomes and colleagues showed that MasR expression and mTor activity were reduced in the hippocampus of the epileptic Ang-(1-7) treated animals. These results show that Ang-(1-7) administration could represent a new avenue for developing strategies for the management of epilepsy in clinical settings. However, future work is necessary to evaluate the levels of RAS metabolites and the activity of key enzymes in these experimental interventions to completely understand the therapeutic potential of the brain RAS manipulation in epilepsy.

scholarly journals Functional expression of the renin-angiotensin system in human podocytes

2006 ◽  
Vol 290 (3) ◽  
pp. F710-F719 ◽  
Author(s):  
Max C. Liebau ◽  
D. Lang ◽  
J. Böhm ◽  
N. Endlich ◽  
Martin J. Bek ◽  
...  
Keyword(s):  
Renin Angiotensin System ◽  
Functional Expression ◽  
Kidney Cortex ◽  
Receptor Subtypes ◽  
Ang Ii ◽  
Angiotensin Receptor ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Beneficial Effects ◽  
Glomerular Proteinuria

Experimental and clinical studies impressively demonstrate that angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) significantly reduce proteinuria and retard progression of glomerular disease. The underlying intraglomerular mechanisms are not yet fully elucidated. As podocyte injury constitutes a critical step in the pathogenesis of glomerular proteinuria, beneficial effects of ACEI and ARB may partially result from interference with a local renin-angiotensin system (RAS) in podocytes. The knowledge of expression and function of a local RAS in podocytes is limited. In this study, we demonstrate functional expression of key components of the RAS in differentiated human podocytes: podocytes express mRNA for angiotensinogen, renin, ACE type 1, and the AT1 and AT2 angiotensin receptor subtypes. In Western blot experiments and immunostainings, expression of the AT1 and AT2 receptor was demonstrated both in differentiated human podocytes and in human kidney cortex. ANG II induced a concentration-dependent increase in cytosolic Ca2+ concentration via AT1 receptors in differentiated human podocytes, whereas it did not increase cAMP. Furthermore, ANG II secretion was detected, which was blocked by neither the ACEI captopril nor the renin inhibitor remikiren nor the chymase inhibitor chymostatin. ANG II secretion of podocytes was not increased by mechanical stress. Finally, ANG II was found to increase staurosporine-induced apoptosis in podocytes. We speculate that ACEI and ARB exert their beneficial effects, in part, by interfering with a local RAS in podocytes. Further experiments are required to identify the underlying molecular mechanism(s) of podocyte protection.

scholarly journals Alternative renin-angiotensin system pathways in adipose tissue and their role in the pathogenesis of obesity

2016 ◽  
Vol 50 (4) ◽  
pp. 229-240 ◽  
Author(s):  
M Slamkova ◽  
S Zorad ◽  
K Krskova
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Renin Angiotensin System ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Alternative Pathways ◽  
Metabolism Regulation ◽  
Mas Receptor ◽  
Glucose And Lipid Metabolism

AbstractAdipose tissue expresses all the renin-angiotensin system (RAS) components that play an important role in the adipogenesis, lipid and glucose metabolism regulation in an auto/paracrine manner. The classical RAS has been found to be over-activated during the adipose tissue enlargement, thus elevated generation of angiotensin II (Ang II) may contribute to the obesity pathogenesis. The contemporary view on the RAS has become more complex with the discovery of alternative pathways, including angiotensin-converting enzyme 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor, (pro)renin receptor, as well as angiotensin IV(Ang IV)/AT4 receptor. Ang-(1-7) via Mas receptor counteracts with most of the deleterious effects of the Ang II-mediated by AT1 receptor implying its beneficial role in the glucose and lipid metabolism, oxidative stress, inflammation, and insulin resistance. Pro(renin) receptor may play a role (at least partial) in the pathogenesis of the obesity by increasing the local production of Ang II in adipose tissue as well as triggering signal transduction independently of Ang II. In this review, modulation of alternative RAS pathways in adipose tissue during obesity is discussed and the involvement of Ang-(1-7), (pro)renin and AT4 receptors in the regulation of adipose tissue homeostasis and insulin resistance is summarized.

scholarly journals The ins and outs of angiotensin processing within the kidney

2014 ◽  
Vol 307 (5) ◽  
pp. R487-R489 ◽  
Author(s):  
Bryan A. Wilson ◽  
Allyson C. Marshall ◽  
Ebaa M. Alzayadneh ◽  
Mark C. Chappell
Keyword(s):  
Renin Angiotensin System ◽  
Target Organ ◽  
Tubular Epithelium ◽  
Ang Ii ◽  
Renal Cells ◽  
Bioactive Components ◽  
Angiotensin System ◽  
Mas Receptor ◽  
Angiotensin Peptides ◽  
Current Review

The kidney is a key target organ for bioactive components of the renin-angiotensin system (RAS); however, various renal cells such as the tubular epithelium contain an intrinsic RAS. The renal RAS can be functionally divided into ANG II-AT1 receptor and ANG-(1–7)-AT7/Mas receptor arms that functionally oppose one another. The current review considers both extracellular and intracellular pathways that potentially govern the formation and metabolism of angiotensin peptides within the renal proximal tubules.

scholarly journals Covid-19: the renin–angiotensin system imbalance hypothesis

2020 ◽  
Vol 134 (11) ◽  
pp. 1259-1264 ◽  
Author(s):  
Katharina Lanza ◽  
Lucas G. Perez ◽  
Larissa B. Costa ◽  
Thiago M. Cordeiro ◽  
Vitria A. Palmeira ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Renin Angiotensin System ◽  
Disease Course ◽  
Ang Ii ◽  
Cellular Mechanisms ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Mas Receptor

Abstract The emergency of SARS-CoV-2 in China started a novel challenge to the scientific community. As the virus turns pandemic, scientists try to map the cellular mechanisms and pathways of SARS-CoV-2 related to the pathogenesis of Coronavirus Disease 2019 (Covid-19). After transmembrane angiotensin-converting enzyme 2 (ACE2) has been found to be SARS-CoV-2 receptor, we hypothesized an immune-hematological mechanism for Covid-19 based on renin–angiotensin system (RAS) imbalance to explain clinical, laboratory and imaging findings on disease course. We believe that exaggerated activation of ACE/Angiotensin II (Ang II)/Angiotensin Type 1 (AT1) receptor RAS axis in line with reduction of ACE2/Angiotensin-(1-7)/Mas receptor may exert a pivotal role in the pathogenesis of Covid-19. In this perspective, we discuss potential mechanisms and evidence on this hypothesis.

scholarly journals Therapeutic Perspectives of Angiotensin-(1-7) in the Treatment of Cardiovascular Disease

2009 ◽  
Vol 3 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Christian Höcht ◽  
Marcos Mayer ◽  
Carlos A. Taira
Keyword(s):  
Cardiovascular Disease ◽  
Renin Angiotensin System ◽  
Therapeutic Strategies ◽  
Biologically Active ◽  
Ang Ii ◽  
Active Components ◽  
Aldosterone Antagonists ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Beneficial Effects

In the last decade, new biologically active components of the renin-angiotensin system were found. Angiotensin-(1-7) (Ang-(1-7)), a metabolite of angiotensin I and angiotensin II (Ang II), is considered the most pleiotropic component of the renin-angiotensin system, acting as a counterregulatory mediator of Ang II. Ang-(1-7) exerts beneficial effects on the cardiovascular system, including reduction of blood pressure, myocardial antihypertrofic and antifibrotic actions, and reversal of renal dysfunction, among others. Recent discovery of enzymatic pathways involved in Ang-(1-7) synthesis, such as the angiotensin-converting enzyme-2 (ACE2) and the existence of a specific receptor to this heptapeptide, the Mas receptor, have increased interest in the design of therapeutic strategies aimed at increasing the biological actions of Ang-(1-7). ACE inhibitors, AT receptor blockers and aldosterone antagonists enhance Ang-(1-7) levels by different mechanisms. Actually, non-peptidic Ang-(1-7) agonists and ACE2 activators are under development and could have a role in the treatment of cardiovascular diseases. The aim of the present review is to describe the biochemical and physiological actions of Ang-(1-7), the therapeutic strategies designed to enhance Ang-(1-7) activity foccusing in their possible role and limitations in the treatment of cardiovascular disease.

scholarly journals Reversal of hyperglycemic preconditioning by angiotensin II: role of calcium transport

2005 ◽  
Vol 288 (4) ◽  
pp. H1965-H1975 ◽  
Author(s):  
Viktor Pastukh ◽  
Songwei Wu ◽  
Craig Ricci ◽  
Mahmood Mozaffari ◽  
Stephen Schaffer
Keyword(s):  
Oxidative Stress ◽  
Calcium Transport ◽  
Renin Angiotensin System ◽  
Myocardial Cell ◽  
Contractile Dysfunction ◽  
Ang Ii ◽  
Angiotensin System ◽  
Beneficial Effects ◽  
Hypoxia Exposure

Myocardial cell death is an important contributor to the development of diabetic cardiomyopathy. It has been proposed that diabetes-mediated upregulation of the renin-angiotensin system leads to oxidative stress, the trigger for cardiomyocyte death and contractile dysfunction. However, the adverse effect of ANG II on the diabetic heart may extend beyond the development of the cardiomyopathy. ANG II also alters specific modulators of ischemic injury, such as PKC and calcium transport. Therefore, the present study examined the effect of ANG II on hyperglycemic preconditioning, a glucose-mediated condition associated with the elevation of PKC activity and alterations in calcium transport that render the cell resistant to hypoxia. Exposure of the glucose-treated cell to ANG II during the prehypoxic period blocked glucose-mediated cardioprotection. The reversal of hyperglycemic preconditioning was associated with enhanced accumulation of Ca2+ during hypoxia, an effect prevented by inhibition of the Na+/ H+ exchanger and the T-type Ca2+ channel. The inhibitors of hypoxia-mediated Ca2+ accumulation also blocked the reversal of hyperglycemic preconditioning by ANG II. Thus ANG II and glucose treatment exert opposite actions on the Na+/ H+ exchanger and the T-type Ca2+ channel. Because those transporters are involved in hypoxia-mediated apoptosis, they are logical candidates for the beneficial effects of high glucose and the adverse effects of ANG II on the hypoxic cardiomyocyte.

Angiotensin 1–7 mediates renoprotection against diabetic nephropathy by reducing oxidative stress, inflammation, and lipotoxicity

2014 ◽  
Vol 306 (8) ◽  
pp. F812-F821 ◽  
Author(s):  
Jun Mori ◽  
Vaibhav B. Patel ◽  
Tharmarajan Ramprasath ◽  
Osama Abo Alrob ◽  
Jessica DesAulniers ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Nephropathy ◽  
Renin Angiotensin System ◽  
Ang Ii ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Beneficial Effects ◽  
Osmotic Pumps ◽  
Characteristic Features ◽  
Transcription 3

The renin-angiotensin system, especially angiotensin II (ANG II), plays a key role in the development and progression of diabetic nephropathy. ANG 1–7 has counteracting effects on ANG II and is known to exert beneficial effects on diabetic nephropathy. We studied the mechanism of ANG 1–7-induced beneficial effects on diabetic nephropathy in db/db mice. We administered ANG 1–7 (0.5 mg·kg−1·day−1) or saline to 5-mo-old db/db mice for 28 days via implanted micro-osmotic pumps. ANG 1–7 treatment reduced kidney weight and ameliorated mesangial expansion and increased urinary albumin excretion, characteristic features of diabetic nephropathy, in db/db mice. ANG 1–7 decreased renal fibrosis in db/db mice, which correlated with dephosphorylation of the signal transducer and activator of transcription 3 (STAT3) pathway. ANG 1–7 treatment also suppressed the production of reactive oxygen species via attenuation of NADPH oxidase activity and reduced inflammation in perirenal adipose tissue. Furthermore, ANG 1–7 treatment decreased lipid accumulation in db/db kidneys, accompanied by increased expressions of renal adipose triglyceride lipase (ATGL). Alterations in ATGL expression correlated with increased SIRT1 expression and deacetylation of FOXO1. The upregulation of angiotensin-converting enzyme 2 levels in diabetic nephropathy was normalized by ANG 1–7. ANG 1–7 treatment exerts renoprotective effects on diabetic nephropathy, associated with reduction of oxidative stress, inflammation, fibrosis, and lipotoxicity. ANG 1–7 can represent a promising therapy for diabetic nephropathy.

scholarly journals Sex-related differences in the intratubular renin-angiotensin system in two-kidney, one-clip hypertensive rats

2019 ◽  
Vol 317 (3) ◽  
pp. F670-F682 ◽  
Author(s):  
Sang Ho Lee ◽  
Yu Ho Lee ◽  
Su Woong Jung ◽  
Dong Jin Kim ◽  
Seon Hwa Park ◽  
...  
Keyword(s):  
Renal Artery ◽  
Renin Angiotensin System ◽  
Female Rats ◽  
Male Rats ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Mas Receptor

The intratubular renin-angiotensin system (RAS) is thought to play an essential role in hypertensive renal disease, but information regarding sex-related differences in this system is limited. The present study investigated sex differences in the intratubular RAS in two-kidney, one-clip (2K1C) rats. A 2.5-mm clip was placed on the left renal artery of Sprague-Dawley rats, and rats were euthanized 3 or 5 wk after the operation. Systolic blood pressure increased in 2K1C rats in both sexes but was significantly higher in male rats than in female rats, and an antihypertensive effect was not observed in 2K1C ovariectomized (OVX) female rats. Compared with male 2K1C rats, intratubular angiotensin-converting enzyme (ACE) and ANG II were repressed, and intratubular ACE2, angiotensin (1–7), and Mas receptor were increased in both kidneys in female 2K1C rats 5 wk after surgery. Comparison with male and female rats and intratubular mRNA levels of ACE and ANG II type 1 receptor were augmented in OVX female rats, regardless of the clipping surgery 3 wk postoperation. ANG II type 2 receptor was upregulated in female rats with or without OVX; thus, the ANG II type 1-to-type 2 receptor ratio was higher in male rats than in female rats. In conclusion, female rats were protected from hypertensive renal and cardiac injury after renal artery clipping. An increase in the intratubular nonclassic RAS [ACE2/angiotensin (1–7)/Mas receptor] and a decrease in the ANG II type 1-to-type 2 receptor ratio could limit the adverse effects of the classic RAS during renovascular hypertension in female rats, and estrogen is suggested to play a primary role in the regulation of intratubular RAS components.

ACE2 as therapeutic agent

2020 ◽  
Vol 134 (19) ◽  
pp. 2581-2595
Author(s):  
Qiuhong Li ◽  
Maria B. Grant ◽  
Elaine M. Richards ◽  
Mohan K. Raizada
Keyword(s):  
Therapeutic Agent ◽  
Renin Angiotensin System ◽  
Peptide Hormone ◽  
Experimental Models ◽  
Electrolyte Balance ◽  
Ang Ii ◽  
Angiotensin Converting Enzyme 2 ◽  
Beneficial Effects ◽  
Overwhelming Evidence ◽  
Future Challenges

Abstract The angiotensin-converting enzyme 2 (ACE2) has emerged as a critical regulator of the renin–angiotensin system (RAS), which plays important roles in cardiovascular homeostasis by regulating vascular tone, fluid and electrolyte balance. ACE2 functions as a carboxymonopeptidase hydrolyzing the cleavage of a single C-terminal residue from Angiotensin-II (Ang-II), the key peptide hormone of RAS, to form Angiotensin-(1-7) (Ang-(1-7)), which binds to the G-protein–coupled Mas receptor and activates signaling pathways that counteract the pathways activated by Ang-II. ACE2 is expressed in a variety of tissues and overwhelming evidence substantiates the beneficial effects of enhancing ACE2/Ang-(1-7)/Mas axis under many pathological conditions in these tissues in experimental models. This review will provide a succinct overview on current strategies to enhance ACE2 as therapeutic agent, and discuss limitations and future challenges. ACE2 also has other functions, such as acting as a co-factor for amino acid transport and being exploited by the severe acute respiratory syndrome coronaviruses (SARS-CoVs) as cellular entry receptor, the implications of these functions in development of ACE2-based therapeutics will also be discussed.

Sign in / Sign up

Export Citation Format

Share Document