Preservation of Glucagon-Like Peptide-1 Level Attenuates Angiotensin II-Induced Tissue Fibrosis by Altering AT1/AT2 Receptor Expression and Angiotensin-Converting Enzyme 2 Activity in Rat Heart

2015 ◽  
Vol 29 (3) ◽  
pp. 243-255 ◽  
Author(s):  
Li-Hui Zhang ◽  
Xue-Fen Pang ◽  
Feng Bai ◽  
Ning-Ping Wang ◽  
Ahmed Ijaz Shah ◽  
...  
TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach

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.


2021 ◽  
Author(s):  
James M. Hill ◽  
Christian Clement ◽  
L. Arceneaux ◽  
Walter Lukiw

Abstract Background: Multiple lines of evidence currently indicate that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)gains entry into human host cells via a high-affinity interaction with the angiotensin-converting enzyme 2 (ACE2) transmembrane receptor. Research has further shown the widespread expression of the ACE2 receptor on the surface of many different immune, non-immune and neural host cell types, and that SARS-CoV-2 has there markable capability to attack many different types of human-host cells simultaneously. One principal neuroanatomical region for highACE2 expression patterns occurs in the brainstem, an area of the brain containing regulatory centers for respiration, and this may in part explain the predisposition of many COVID-19 patients to respiratory distress. Early studies also indicated extensive ACE2 expression in the whole eye and the brain’s visual circuitry. In this study we analyzed ACE2 receptor expression at the mRNA and protein level in multiple cell types involved in human vision, including cell types of the external eye and several deep brain regions known to be involved in the processing of visual signals.Methods: ACE2 mRNA and protein analysis; multiple eye and brain cells and tissues; gamma32P-adenosine tri-phosphate ([γ-32P]dATP) radiolabeled probes; Northern analysis; ELISA.Results: The four main findings were: (i)that many different optical and neural cell types of the human visual system provide receptors essential for SARS-CoV-2 invasion; (ii)the remarkable ubiquity of ACE2 presence in cells of the eye and anatomical regions of the brain involved in visual signal processing; (iii)that ACE2 receptor expression in different ocular cell types and visual processing centers of the brain provide multiple compartments for SARS-CoV-2 infiltration; and (iv)a gradient of increasing ACE2 expression from the anterior surface of the eye to the visual signal processing areas of the occipital lobe and the primary visual neocortex.Conclusion: A gradient of ACE2 expression from the eye surface to the occipital lobe provide the SARS-CoV-2 virus a novel pathway from the outer eye into deeper anatomical regions of the brain involved in vision. These findings may explain, in part, the many recently reported neuro-ophthalmic manifestations of SARS-CoV-2infection in COVID-19 affected patients.


Hypertension ◽  
2010 ◽  
Vol 55 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Jan Wysocki ◽  
Minghao Ye ◽  
Eva Rodriguez ◽  
Francisco R. González-Pacheco ◽  
Clara Barrios ◽  
...  

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Nisha Sharma ◽  
Anil Bhanudas Gaikwad

Abstract Background and Aims In clinical settings, diabetics remain on higher risk of ischemic renal injury (IRI) than nondiabetic patients. In addition, IRI predisposes distant organs to dysfunction such as neurological impairments via activation of the pressor arm of renin-angiotensin system (RAS). In contrast, the role of depressor arm of RAS on IRI-associated neurological sequalae remains elusive. Hence, this study explored the role of angiotensin II type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2) in IRI-associated neurological dysfunctions under nondiabetic (ND) and diabetes mellitus (DM) condition. Method Type 1 diabetes was induced by injecting streptozotocin (55 mg/kg i.p.). ND and DM rats with bilateral IRI were treated with AT2R agonist-Compound 21 (C21) (0.3 mg/kg/day, i.p.) or ACE2 activator-Diminazene Aceturate (Dize), (5 mg/kg/day, p.o.) per se or in combination therapy. Behavioural, biochemical, and histopathological analysis were done to assess IRI-induced neurological impairment. Moreover, immunohistochemistry, ELISA and qRT-PCR experiments were conducted for molecular mechanism analysis. Result In ND and DM rats, IRI caused hippocampal complications as evidenced by increased MDA and nitrite levels, augmented inflammatory cytokines (granulocyte colony stimulating factor, glial fibrillary acidic protein), altered protein and mRNA expressions of Ang II, Ang-(1-7), AT1R, AT2R and MasR. In contrast, concomitant therapy of C21 and Dize effectively normalised aforementioned hippocampal alterations. The protective effect of combination therapy was exerted due to augmented protein and mRNA levels of depressor arm components. Conclusion The current study demonstrated the protective role of AT2R agonist and ACE2 activator in IRI-associated neurological dysfunction through preventing oxidative stress, inflammation and upregulating brain depressor arm of RAS under ND and DM conditions.


2020 ◽  
Vol 103 (3) ◽  
pp. 449-451 ◽  
Author(s):  
Saguna Verma ◽  
Sarini Saksena ◽  
Hooman Sadri-Ardekani

Expression of angiotensin-converting enzyme 2, receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is high in the testes, therefore SARS-CoV-2 infection and its association with male reproductive health should be investigated in male coronavirus disease 2019 patients.


2020 ◽  
Vol 10 (18) ◽  
pp. 6224 ◽  
Author(s):  
Leonardo Mancini ◽  
Vincenzo Quinzi ◽  
Stefano Mummolo ◽  
Giuseppe Marzo ◽  
Enrico Marchetti

SARS-CoV-2 propagation in the world has led to rapid growth and an acceleration in the discoveries and publications of various interests. The main focus of a consistent number of studies has been the role of angiotensin-converting enzyme 2 (ACE2) in binding the virus and its role in expression of the inflammatory response after transmission. ACE2 is an enzyme involved in the renin–angiotensin system (RAS), whose key role is to regulate and counter angiotensin-converting enzyme (ACE), reducing the amount of angiotensin II and increasing angiotensin 1–7 (Ang1–7), making it a promising drug target for treating cardiovascular diseases. The classical RAS axis, formed by ACE, angiotensin II (Ang II), and angiotensin receptor type 1 (AT1), activates several cell functions and molecular signalling pathways related to tissue injury and inflammation. In contrast, the RAS axis composed of ACE2, Ang1–7, and Mas receptor (MasR) exerts the opposite effect concerning the inflammatory response and tissue fibrosis. Recent studies have shown the presence of the RAS system in periodontal sites where osteoblasts, fibroblasts, and osteoclasts are involved in bone remodelling, suggesting that the role of ACE2 might have a fundamental function in the under- or overexpression of cytokines such as interleukin-6 (IL-6), interleukin-7 (IL-7), tumour necrosis factor alpha (TNF-α), interleukin-2 (IL-2), interleukin-1 beta (IL-1β), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta (TGF-β), associated with a periodontal disorder, mainly during coinfection with SARS-CoV-2, where ACE2 is underexpressed and cannot form the ACE2–Ang1–7–MasR axis. This renders the patient unresponsive to an inflammatory process, facilitating periodontal loss.


2005 ◽  
Vol 289 (6) ◽  
pp. H2281-H2290 ◽  
Author(s):  
Carlos M. Ferrario ◽  
Aaron J. Trask ◽  
Jewell A. Jessup

Angiotensin-converting enzyme 2 (ACE2) is the first human homologue of ACE to be described. ACE2 is a type I integral membrane protein that functions as a carboxypeptidase, cleaving a single hydrophobic/basic residue from the COOH-terminus of its substrates. Because ACE2 efficiently hydrolyzes the potent vasoconstrictor angiotensin II to angiotensin (1–7), this has changed our overall perspective about the classical view of the renin angiotensin system in the regulation of hypertension and heart and renal function, because it represents the first example of a feedforward mechanism directed toward mitigation of the actions of angiotensin II. This paper reviews the new data regarding the biochemistry of angiotensin-(1–7)-forming enzymes and discusses key findings such as the elucidation of the regulatory mechanisms participating in the expression of ACE2 and angiotensin-(1–7) in the control of the circulation.


Sign in / Sign up

Export Citation Format

Share Document