New fACEs to the Renin-Angiotensin System

Physiology ◽  
2005 ◽  
Vol 20 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Ingrid Fleming ◽  
Karin Kohlstedt ◽  
Rudi Busse
Keyword(s):  
Angiotensin Ii ◽  
Cardiovascular Diseases ◽  
Angiotensin Converting Enzyme ◽  
Kidney Function ◽  
Ace Inhibitors ◽  
Renin Angiotensin System ◽  
Signaling Cascade ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Beneficial Effects

Inhibition of the angiotensin-converting enzyme (ACE) protects against the progression of several cardiovascular diseases. Recent evidence suggests that some of the beneficial effects of ACE inhibitors can be attributed to the activation of a distinct ACE signaling cascade rather than to the changes in angiotensin II and bradykinin levels. Moreover, at least one other ACE homolog (ACE2) plays a significant role in the regulation of heart and kidney function.

scholarly journals Pathological Role of Angiotensin II in Severe COVID-19

TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Treatment Options ◽  
Renin Angiotensin System ◽  
Target Cells ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Novel Coronavirus

AbstractThe activated renin–angiotensin system induces a prothrombotic state resulting from the imbalance between coagulation and fibrinolysis. Angiotensin II is the central effector molecule of the activated renin–angiotensin system and is degraded by the angiotensin-converting enzyme 2 to angiotensin (1–7). The novel coronavirus infection (classified as COVID-19) is caused by the new coronavirus SARS-CoV-2 and is characterized by an exaggerated inflammatory response that can lead to severe manifestations such as acute respiratory distress syndrome, sepsis, and death in a proportion of patients, mostly elderly patients with preexisting comorbidities. SARS-CoV-2 uses the angiotensin-converting enzyme 2 receptor to enter the target cells, resulting in activation of the renin–angiotensin system. After downregulating the angiotensin-converting enzyme 2, the vasoconstrictor angiotensin II is increasingly produced and its counterregulating molecules angiotensin (1–7) reduced. Angiotensin II increases thrombin formation and impairs fibrinolysis. Elevated levels were strongly associated with viral load and lung injury in patients with severe COVID-19. Therefore, the complex clinical picture of patients with severe complications of COVID-19 is triggered by the various effects of highly expressed angiotensin II on vasculopathy, coagulopathy, and inflammation. Future treatment options should focus on blocking the thrombogenic and inflammatory properties of angiotensin II in COVID-19 patients.

Resveratrol ameliorates the cyclosporine-induced vascular and renal impairments: possible impact of the modulation of renin–angiotensin system

2019 ◽  
Vol 97 (12) ◽  
pp. 1115-1123 ◽  
Author(s):  
Seldag Bekpinar ◽  
Ece Karaca ◽  
Selin Yamakoğlu ◽  
F. İlkay Alp-Yıldırım ◽  
Vakur Olgac ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Immunosuppressive Drug ◽  
Oxidative Stress Marker ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
System Components ◽  
Renal Tubular

Cyclosporine, an immunosuppressive drug, exhibits a toxic effect on renal and vascular systems. The present study investigated whether resveratrol treatment alleviates renal and vascular injury induced by cyclosporine. Cyclosporine (25 mg/kg per day, s.c.) was given for 7 days to rats either alone or in combination with resveratrol (10 mg/kg per day, i.p.). Relaxation and contraction responses of aorta were examined. Serum levels of blood urea nitrogen, creatinine, angiotensin II, and angiotensin 1-7 were measured. Histopathological examinations as well as immunostaining for 4-hydroxynonenal and nitrotyrosine were performed in the kidney. RNA expressions of renin–angiotensin system components were also measured in renal and aortic tissues. Cyclosporine decreased the endothelium-dependent relaxation and increased vascular contraction in the aorta. It caused renal tubular degeneration and increased immunostaining for 4-hydroxynonenal, an oxidative stress marker. Cyclosporine also caused upregulations of the vasoconstrictive renin–angiotensin system components in renal (angiotensin-converting enzyme) and aortic (angiotensin II type 1 receptor) tissues. Resveratrol co-treatment prevented the cyclosporine-related deteriorations. Moreover, it induced the expressions of vasodilatory effective angiotensin-converting enzyme 2 and angiotensin II type 2 receptor in aorta and kidney, respectively. We conclude that resveratrol may be effective in preventing cyclosporine-induced renal tubular degeneration and vascular dysfunction at least in part by modulating the renin–angiotensin system.

scholarly journals Association of seven renin angiotensin system gene polymorphisms with restenosis in patients following coronary stenting

2017 ◽  
Vol 18 (1) ◽  
pp. 147032031668877 ◽  
Author(s):  
Min Zhu ◽  
Minjun Yang ◽  
Jiangbo Lin ◽  
Huanhuan Zhu ◽  
Yifei Lu ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Neointimal Hyperplasia ◽  
Renin Angiotensin System ◽  
Coronary Stenting ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Stent Restenosis ◽  
In Stent Restenosis

Background and objective: Percutaneous coronary intervention, despite being effective for coronary revascularization, causes in-stent restenosis due to neointimal hyperplasia in a large number of patients. The renin-angiotensin system is involved in neointimal hyperplasia. This study sought to evaluate seven gene polymorphisms of key renin-angiotensin system components, including angiotensinogen, angiotensin-converting enzyme and angiotensin II type 1a receptors, and their associations with in-stent restenosis in patients with coronary artery disease following coronary stenting. Methods and results: Three hundred and fifty-two patients undergoing coronary drug-eluting stent implantation were recruited. Seventy-five patients (21.3%) were diagnosed as restenosis by angiography. Genotyping for angiotensin-converting enzyme insertion/deletion demonstrated a significant association of angiotensin-converting enzyme DD genotype with the occurrence of restenosis. Direct DNA sequencing revealed no association of angiotensinogen (M235T, G217A, G152A, G-6A, and A-20C) or angiotensin II type I receptor A1166C polymorphisms with in-stent restenosis. However, angiotensin II type 1a A1166C polymorphism was significantly associated with increased susceptibility to restenosis in a subgroup of patients aged more than 60 years. Conclusion: Thus, our study suggests that genetic polymorphisms of angiotensin-converting enzyme insertion/deletion are associated with in-stent restenosis in coronary artery disease patients following coronary stenting.

scholarly journals Renin-Angiotensin System Blockers and the COVID-19 Pandemic

Hypertension ◽  
2020 ◽  
Vol 75 (6) ◽  
pp. 1382-1385 ◽  
Author(s):  
A.H. Jan Danser ◽  
Murray Epstein ◽  
Daniel Batlle
Keyword(s):  
Angiotensin Ii ◽  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Receptor Blockers ◽  
Renin Angiotensin System Blockers

During the spread of the severe acute respiratory syndrome coronavirus-2, some reports of data still emerging and in need of full analysis indicate that certain groups of patients are at risk of COVID-19. This includes patients with hypertension, heart disease, diabetes mellitus, and clearly the elderly. Many of those patients are treated with renin-angiotensin system blockers. Because the ACE2 (angiotensin-converting enzyme 2) protein is the receptor that facilitates coronavirus entry into cells, the notion has been popularized that treatment with renin-angiotensin system blockers might increase the risk of developing a severe and fatal severe acute respiratory syndrome coronavirus-2 infection. The present article discusses this concept. ACE2 in its full-length form is a membrane-bound enzyme, whereas its shorter (soluble) form circulates in blood at very low levels. As a mono-carboxypeptidase, ACE2 contributes to the degradation of several substrates including angiotensins I and II. ACE (angiotensin-converting enzyme) inhibitors do not inhibit ACE2 because ACE and ACE2 are different enzymes. Although angiotensin II type 1 receptor blockers have been shown to upregulate ACE2 in experimental animals, the evidence is not always consistent and differs among the diverse angiotensin II type 1 receptor blockers and differing organs. Moreover, there are no data to support the notion that ACE inhibitor or angiotensin II type 1 receptor blocker administration facilitates coronavirus entry by increasing ACE2 expression in either animals or humans. Indeed, animal data support elevated ACE2 expression as conferring potential protective pulmonary and cardiovascular effects. In summary, based on the currently available evidence, treatment with renin-angiotensin system blockers should not be discontinued because of concerns with coronavirus infection.

scholarly journals Chymase-dependent production of angiotensin II: an old enzyme in old hearts

2017 ◽  
Vol 312 (2) ◽  
pp. H223-H231 ◽  
Author(s):  
Ghezal Froogh ◽  
John T. Pinto ◽  
Yicong Le ◽  
Sharath Kandhi ◽  
Yeabsra Aleligne ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Ang Ii ◽  
Aged Rats ◽  
Converting Enzyme ◽  
Local Formation ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Age Dependent

Age-dependent alteration of the renin-angiotensin system (RAS) and generation of angiotensin II (Ang II) are well documented. By contrast, RAS-independent generation of Ang II in aging and its responses to exercise have not been explored. To this end, we examined the effects of chymase, a secretory serine protease, on the angiotensin-converting enzyme (ACE)-independent conversion of Ang I to Ang II. We hypothesized that age-dependent alteration of cardiac Ang II formation is chymase dependent in nature and is prevented by exercise training. Experiments were conducted on hearts isolated from young (3 mo), aged sedentary (24 mo), and aged rats chronically exercised on a treadmill. In the presence of low Ang I levels and downregulation of ACE expression/activity, cardiac Ang II levels were significantly higher in aged than young rats, suggesting an ACE-independent response. Aged hearts also displayed significantly increased chymase expression and activity, as well as upregulation of tryptase, a biological marker of mast cells, confirming a mast cell-sourced increase in chymase. Coincidently, cardiac superoxide produced from NADPH oxidase (Nox) was significantly enhanced in aged rats and was normalized by exercise. Conversely, a significant reduction in cardiac expression of ACE2 followed by lower Ang 1-7 levels and downregulation of the Mas receptor (binding protein of Ang 1-7) in aged rats were completely reversed by exercise. In conclusion, local formation of Ang II is increased in aged hearts, and chymase is primarily responsible for this increase. Chronic exercise is able to normalize the age-dependent alterations via compromising chymase/Ang II/angiotensin type 1 receptor/Nox actions while promoting ACE2/Ang 1-7/MasR signaling. NEW & NOTEWORTHY Aging increases angiotensin-converting enzyme (ACE)-independent production of cardiac angiotensin II (Ang II), a response that is driven by chymase in an exercise-reversible manner. These findings highlight chymase, in addition to ACE, as an important therapeutic target in the treatment and prevention of Ang II-induced deterioration of cardiac function in the elderly. Listen to this article's corresponding podcast @ http://ajpheart.podbean.com/e/renin-angiotensin-system-signaling-in-aged-and-age-exercised-rats/ .

scholarly journals Functional Complexes of Angiotensin-Converting Enzyme 2 and Renin-Angiotensin System Receptors: Expression in Adult but Not Fetal Lung Tissue

2020 ◽  
Vol 21 (24) ◽  
pp. 9602
Author(s):  
Rafael Franco ◽  
Alejandro Lillo ◽  
Rafael Rivas-Santisteban ◽  
Ana I. Rodríguez-Pérez ◽  
Irene Reyes-Resina ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cell Surface ◽  
Angiotensin Converting Enzyme ◽  
Ligand Binding ◽  
Renin Angiotensin System ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2

Angiotensin-converting enzyme 2 (ACE2) is a membrane peptidase and a component of the renin-angiotensin system (RAS) that has been found in cells of all organs, including the lungs. While ACE2 has been identified as the receptor for severe acute respiratory syndrome (SARS) coronaviruses, the mechanism underlying cell entry remains unknown. Human immunodeficiency virus infects target cells via CXC chemokine receptor 4 (CXCR4)-mediated endocytosis. Furthermore, CXCR4 interacts with dipeptidyl peptidase-4 (CD26/DPPIV), an enzyme that cleaves CXCL12/SDF-1, which is the chemokine that activates this receptor. By analogy, we hypothesized that ACE2 might also be capable of interactions with RAS-associated G-protein coupled receptors. Using resonance energy transfer and cAMP and mitogen-activated protein kinase signaling assays, we found that human ACE2 interacts with RAS-related receptors, namely the angiotensin II type 1 receptor (AT1R), the angiotensin II type 2 receptor (AT2R), and the MAS1 oncogene receptor (MasR). Although these interactions led to various alterations of signal transduction, but, more importantly, ligand binding to AT1R resulted in the downregulation of ACE2 cell surface expression, while ligand binding to AT2R, but not to MasR, resulted in upregulation of ACE2 cell surface expression. Proximity ligation assays performed in situ revealed macromolecular complexes containing ACE2 and AT1R, AT2R or MasR in adult but not fetal mouse lung tissue. These findings highlight the relevance of RAS in SARS-CoV-2 infection and the role of ACE2-containing complexes as potential therapeutic targets.

scholarly journals The Uterine Placental Bed Renin-Angiotensin System in Normal and Preeclamptic Pregnancy

Endocrinology ◽  
2009 ◽  
Vol 150 (9) ◽  
pp. 4316-4325 ◽  
Author(s):  
Lauren Anton ◽  
David C. Merrill ◽  
Liomar A. A. Neves ◽  
Debra I. Diz ◽  
Jenny Corthorn ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Mrna Expression ◽  
Receptor Binding ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Angiotensin Receptor ◽  
Angiotensin System ◽  
Chorionic Villi ◽  
Renin Angiotensin

Abstract Previously, we demonstrated activation of the renin-angiotensin system in the fetal placental chorionic villi, but it is unknown whether the immediately adjacent area of the maternal uterine placental bed is regulated similarly. This study measured angiotensin peptides, renin-angiotensin system component mRNAs, and receptor binding in the fundus from nonpregnant subjects (n = 19) and in the uterine placental bed from normal (n = 20) and preeclamptic (n = 14) subjects. In the uterine placental bed from normal pregnant women, angiotensin II peptide levels and angiotensinogen, angiotensin-converting enzyme, angiotensin receptor type 1 (AT1), AT2, and Mas mRNA expression were lower as compared with the nonpregnant subjects. In preeclamptic uterine placental bed, angiotensin II peptide levels and renin and angiotensin-converting enzyme mRNA expression were significantly higher than normal pregnant subjects. The AT2 receptor was the predominant receptor subtype in the nonpregnant fundus, whereas all angiotensin receptor binding was undetectable in normal and preeclamptic pregnant uterine placental bed compared with nonpregnant fundus. These findings suggest that the maternal uterine placental bed may play an endocrine role by producing angiotensin II, which acts in the adjacent placenta to vasoconstrict fetal chorionic villi vessels where we have shown previously that AT1 receptors predominate. This would lead to decreased maternal-fetal oxygen exchange and fetal nutrition, a known characteristic of preeclampsia.

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