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1.
Int J Mol Sci ; 23(11)2022 Jun 06.
Article in English | MEDLINE | ID: covidwho-1884210

ABSTRACT

This review is dedicated to the cross-talk between the (endo)cannabinoid and renin angiotensin systems (RAS). Activation of AT1 receptors (AT1Rs) by angiotensin II (Ang II) can release endocannabinoids that, by acting at cannabinoid CB1 receptors (CB1Rs), modify the response to AT1R stimulation. CB1R blockade may enhance AT1R-mediated responses (mainly vasoconstrictor effects) or reduce them (mainly central nervous system-mediated effects). The final effects depend on whether stimulation of CB1Rs and AT1Rs induces opposite or the same effects. Second, CB1R blockade may diminish AT1R levels. Third, phytocannabinoids modulate angiotensin-converting enzyme-2. Additional studies are required to clarify (1) the existence of a cross-talk between the protective axis of the RAS (Ang II-AT2 receptor system or angiotensin 1-7-Mas receptor system) with components of the endocannabinoid system, (2) the influence of Ang II on constituents of the endocannabinoid system and (3) the (patho)physiological significance of AT1R-CB1R heteromerization. As a therapeutic consequence, CB1R antagonists may influence effects elicited by the activation or blockade of the RAS; phytocannabinoids may be useful as adjuvant therapy against COVID-19; single drugs acting on the (endo)cannabinoid system (cannabidiol) and the RAS (telmisartan) may show pharmacokinetic interactions since they are substrates of the same metabolizing enzyme of the transport mechanism.


Subject(s)
COVID-19 , Cannabinoids , Angiotensin II/metabolism , Cannabinoids/pharmacology , Endocannabinoids/pharmacology , Humans , Receptor, Angiotensin, Type 1/metabolism , Receptors, Angiotensin/metabolism , Receptors, Cannabinoid , Renin/pharmacology , Renin-Angiotensin System
2.
Biomed Pharmacother ; 152: 113201, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1866912

ABSTRACT

BACKGROUND: Besides its counterbalancing role of the renin-angiotensin system (RAS), angiotensin-converting enzyme (ACE) 2 is the receptor for the type 2 coronavirus that causes severe acute respiratory syndrome, the etiological agent of COVID-19. COVID-19 is associated with increased plasmatic ACE2 levels, although conflicting results have been reported regarding angiotensin (Ang) II and Ang-(1-7) levels. We investigated plasmatic ACE2 protein levels and enzymatic activity and Ang II and Ang-(1-7) levels in normotensive and hypertensive patients hospitalized with COVID-19 compared to healthy subjects. METHODS: Ang II and Ang-(1-7), and ACE2 activity and protein levels were measured in 93 adults (58 % (n = 54) normotensive and 42 % (n = 39) hypertensive) hospitalized with COVID-19. Healthy, normotensive (n = 33) and hypertensive (n = 7) outpatient adults comprised the control group. RESULTS: COVID-19 patients displayed higher ACE2 enzymatic activity and protein levels than healthy subjects. Within the COVID-19 group, ACE2 activity and protein levels were not different between normotensive and hypertensive-treated patients, not even between COVID-19 hypertensive patients under RAS blockade treatment and those treated with other antihypertensive medications. Ang II and Ang-(1-7) levels significantly decreased in COVID-19 patients. When COVID-19 patients under RAS blockade treatment were excluded from the analysis, ACE2 activity and protein levels remained higher and Ang II and Ang-(1-7) levels lower in COVID-19 patients compared to healthy people. CONCLUSIONS: Our results support the involvement of RAS in COVID-19, even when patients under RAS blockade treatment were excluded. The increased circulating ACE2 suggest higher ACE2 expression and shedding.


Subject(s)
COVID-19 , Hypertension , Adult , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2 , Humans , Peptidyl-Dipeptidase A/metabolism , Renin-Angiotensin System
3.
Int J Mol Sci ; 23(9)2022 May 04.
Article in English | MEDLINE | ID: covidwho-1820297

ABSTRACT

Blockers of the renin-angiotensin system (RAS) have been reported to increase the angiotensin converting enzyme (ACE)2, the cellular receptor of SARS-CoV-2, and thus the risk and course of COVID-19. Therefore, we investigated if angiotensin (Ang) II and RAS blockers affected ACE2 expression and SARS-CoV-2 infectivity in human epithelial bronchial Calu-3 cells. By infectivity and spike-mediated cell-cell fusion assays, we showed that Ang II acting on the angiotensin type 1 receptor markedly increased ACE2 at mRNA and protein levels, resulting in enhanced SARS-CoV-2 cell entry. These effects were abolished by irbesartan and not affected by the blockade of ACE-1-mediated Ang II formation with ramipril, and of ACE2- mediated Ang II conversion into Ang 1-7 with MLN-4760. Thus, enhanced Ang II production in patients with an activated RAS might expose to a greater spread of COVID-19 infection in lung cells. The protective action of Angiotensin type 1 receptor antagonists (ARBs) documented in these studies provides a mechanistic explanation for the lack of worse outcomes in high-risk COVID-19 patients on RAS blockers.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Angiotensin II/metabolism , Angiotensin II/pharmacology , Angiotensin Receptor Antagonists/pharmacology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Humans , Receptor, Angiotensin, Type 1/genetics , Receptor, Angiotensin, Type 1/metabolism , Renin-Angiotensin System , SARS-CoV-2 , Up-Regulation
4.
Cardiovasc Toxicol ; 22(4): 311-325, 2022 04.
Article in English | MEDLINE | ID: covidwho-1773006

ABSTRACT

Hypertension is one of the most prevalent cardiovascular disorders worldwide, affecting 1.13 billion people, or 14% of the global population. Hypertension is the single biggest risk factor for cerebrovascular dysfunction. According to the American Heart Association, high blood pressure (BP), especially in middle-aged individuals (~ 40 to 60 years old), is associated with an increased risk of dementia, later in life. Alzheimer's disease and cerebrovascular disease are the two leading causes of dementia, accounting for around 80% of the total cases and usually combining mixed pathologies from both. Little is known regarding how hypertension affects cognitive function, so the impact of its treatment on cognitive impairment has been difficult to assess. The brain renin-angiotensin system (RAS) is essential for BP regulation and overactivity of this system has been established to precede the development and maintenance of hypertension. Angiotensin II (Ang-II), the main peptide within this system, induces vasoconstriction and impairs neuro-vascular coupling by acting on brain Ang-II type 1 receptors (AT1R). In this review, we systemically analyzed the association between RAS and biological mechanisms of cognitive impairment, from the perspective of AT1R located in the central nervous system. Additionally, the possible contribution of brain AT1R to global cognition decline in COVID-19 cases will be discussed as well.


Subject(s)
COVID-19 , Cognitive Dysfunction , Hypertension , Adult , Angiotensin II/metabolism , Blood Pressure/physiology , COVID-19/complications , Cognitive Dysfunction/diagnosis , Humans , Hypertension/diagnosis , Middle Aged , Receptor, Angiotensin, Type 1/metabolism , Renin-Angiotensin System
5.
Int J Mol Sci ; 23(5)2022 Feb 22.
Article in English | MEDLINE | ID: covidwho-1736940

ABSTRACT

Contrary to public perception, hypertension remains one of the most important public health problems in the United States, affecting 46% of adults with increased risk for heart attack, stroke, and kidney diseases. The mechanisms underlying poorly controlled hypertension remain incompletely understood. Recent development in the Cre/LoxP approach to study gain or loss of function of a particular gene has significantly helped advance our new insights into the role of proximal tubule angiotensin II (Ang II) and its AT1 (AT1a) receptors in basal blood pressure control and the development of Ang II-induced hypertension. This novel approach has provided us and others with an important tool to generate novel mouse models with proximal tubule-specific loss (deletion) or gain of the function (overexpression). The objective of this invited review article is to review and discuss recent findings using novel genetically modifying proximal tubule-specific mouse models. These new studies have consistently demonstrated that deletion of AT1 (AT1a) receptors or its direct downstream target Na+/H+ exchanger 3 (NHE3) selectively in the proximal tubules of the kidney lowers basal blood pressure, increases the pressure-natriuresis response, and induces natriuretic responses, whereas overexpression of an intracellular Ang II fusion protein or AT1 (AT1a) receptors selectively in the proximal tubules increases proximal tubule Na+ reabsorption, impairs the pressure-natriuresis response, and elevates blood pressure. Furthermore, the development of Ang II-induced hypertension by systemic Ang II infusion or by proximal tubule-specific overexpression of an intracellular Ang II fusion protein was attenuated in mutant mice with proximal tubule-specific deletion of AT1 (AT1a) receptors or NHE3. Thus, these recent studies provide evidence for and new insights into the important roles of intratubular Ang II via AT1 (AT1a) receptors and NHE3 in the proximal tubules in maintaining basal blood pressure homeostasis and the development of Ang II-induced hypertension.


Subject(s)
Angiotensin II/metabolism , Hypertension/metabolism , Receptor, Angiotensin, Type 1/metabolism , Angiotensin II/genetics , Animals , Blood Pressure , Disease Models, Animal , Gain of Function Mutation , Humans , Hypertension/genetics , Loss of Function Mutation , Mice , Receptor, Angiotensin, Type 1/genetics , Sodium-Hydrogen Exchanger 3/metabolism
6.
Life Sci ; 293: 120324, 2022 Mar 15.
Article in English | MEDLINE | ID: covidwho-1616648

ABSTRACT

AIMS: Angiotensin-converting enzyme (ACE) 2 is the receptor for severe acute respiratory syndrome coronavirus 2 which causes coronavirus disease 2019 (COVID-19). Viral cellular entry requires ACE2 and transmembrane protease serine 2 (TMPRSS2). ACE inhibitors (ACEIs) or angiotensin (Ang) receptor blockers (ARBs) influence ACE2 in animals, though evidence in human lungs is lacking. We investigated ACE2 and TMPRSS2 in type II pneumocytes, the key cells that maintain lung homeostasis, in lung parenchymal of ACEI/ARB-treated subjects compared to untreated control subjects. MAIN METHODS: Ang II and Ang-(1-7) levels and ACE2 and TMPRSS2 protein expression were measured by radioimmunoassay and immunohistochemistry, respectively. KEY FINDINGS: We found that the ratio Ang-(1-7)/Ang II, a surrogate marker of ACE2 activity, as well as the amount of ACE2-expressing type II pneumocytes were not different between ACEI/ARB-treated and untreated subjects. ACE2 protein content correlated positively with smoking habit and age. The percentage of TMPRSS2-expressing type II pneumocytes was higher in males than females and in subjects under 60 years of age but it was not different between ACEI/ARB-treated and untreated subjects. However, there was a positive association of TMPRSS2 protein content with age and smoking in ACEI/ARB-treated subjects, with high TMPRSS2 protein levels most evident in ACEI/ARB-treated older adults and smokers. SIGNIFICANCE: ACEI/ARB treatment influences human lung TMPRSS2 but not ACE2 protein content and this effect is dependent on age and smoking habit. This finding may help explain the increased susceptibility to COVID-19 seen in smokers and older patients with treated cardiovascular-related pathologies.


Subject(s)
Alveolar Epithelial Cells/metabolism , Angiotensin Receptor Antagonists/pharmacology , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Renin-Angiotensin System/physiology , Serine Endopeptidases/metabolism , Adult , Age Factors , Aged , Alveolar Epithelial Cells/chemistry , Alveolar Epithelial Cells/drug effects , Angiotensin I/metabolism , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/analysis , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Female , Humans , Lung/chemistry , Lung/drug effects , Lung/metabolism , Male , Middle Aged , Peptide Fragments/metabolism , Renin-Angiotensin System/drug effects , Retrospective Studies , Serine Endopeptidases/analysis , Smoking/metabolism , Smoking/pathology
7.
PLoS Biol ; 19(12): e3001510, 2021 12.
Article in English | MEDLINE | ID: covidwho-1592147

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infects a broader range of mammalian species than previously predicted, binding a diversity of angiotensin converting enzyme 2 (ACE2) orthologs despite extensive sequence divergence. Within this sequence degeneracy, we identify a rare sequence combination capable of conferring SARS-CoV-2 resistance. We demonstrate that this sequence was likely unattainable during human evolution due to deleterious effects on ACE2 carboxypeptidase activity, which has vasodilatory and cardioprotective functions in vivo. Across the 25 ACE2 sites implicated in viral binding, we identify 6 amino acid substitutions unique to mouse-one of the only known mammalian species resistant to SARS-CoV-2. Substituting human variants at these positions is sufficient to confer binding of the SARS-CoV-2 S protein to mouse ACE2, facilitating cellular infection. Conversely, substituting mouse variants into either human or dog ACE2 abolishes viral binding, diminishing cellular infection. However, these same substitutions decrease human ACE2 activity by 50% and are predicted as pathogenic, consistent with the extreme rarity of human polymorphisms at these sites. This trade-off can be avoided, however, depending on genetic background; if substituted simultaneously, these same mutations have no deleterious effect on dog ACE2 nor that of the rodent ancestor estimated to exist 70 million years ago. This genetic contingency (epistasis) may have therefore opened the road to resistance for some species, while making humans susceptible to viruses that use these ACE2 surfaces for binding, as does SARS-CoV-2.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Disease Resistance/genetics , Epistasis, Genetic , SARS-CoV-2/physiology , Amino Acids , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Animals , Binding Sites , COVID-19/enzymology , COVID-19/genetics , Dogs , Evolution, Molecular , Gene Frequency , Humans , Hydrolysis , Mice , Mutation , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment
8.
Rev Med Virol ; 31(5): 1-12, 2021 09.
Article in English | MEDLINE | ID: covidwho-1575376

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the host cell by binding to angiotensin-converting enzyme 2 (ACE2) receptor. Other important proteins involved in this process include disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) also known as tumour necrosis factor-α-converting enzyme and transmembrane serine protease 2. ACE2 converts angiotensin II (Ang II) to angiotensin (1-7), to balance the renin angiotensin system. Membrane-bound ACE2 ectodomain shedding is mediated by ADAM17 upon viral spike binding, Ang II overproduction and in several diseases. The shed soluble ACE2 (sACE2) retains its catalytic activity, but its precise role in viral entry is still unclear. Therapeutic sACE2 is claimed to exert dual effects; reduction of excess Ang II and blocking viral entry by masking the spike protein. Nevertheless, the paradox is why SARS-CoV-2 comorbid patients struggle to attain such benefit in viral infection despite having a high amount of sACE2. In this review, we discuss the possible detrimental role of sACE2 and speculate on a series of events where protease primed or non-primed virus-sACE2 complex might enter the host cell. As extracellular virus can bind many sACE2 molecules, sACE2 level could be reduced drastically upon endocytosis by the host cell. A consequential rapid rise in Ang II level could potentially aggravate disease severity through Ang II-angiotensin II receptor type 1 (AT1R) axis in comorbid patients. Hence, monitoring sACE2 and Ang II level in coronavirus disease 2019 comorbid patients are crucial to ensure safe and efficient intervention using therapeutic sACE2 and vaccines.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/enzymology , ADAM17 Protein/genetics , ADAM17 Protein/metabolism , Angiotensin I/metabolism , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/genetics , COVID-19/virology , Comorbidity , Humans , Peptide Fragments/metabolism , SARS-CoV-2/physiology
9.
J Renin Angiotensin Aldosterone Syst ; 2021: 6824259, 2021.
Article in English | MEDLINE | ID: covidwho-1546597

ABSTRACT

Coronavirus disease 2019 (COVID-19) can occur due to contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has no confined treatment and, consequently, has high hospitalization and mortality rates. Moreover, people who contract COVID-19 present systemic inflammatory spillover. It is now known that COVID-19 pathogenesis is linked to the renin-angiotensin system (RAS). COVID-19 invades host cells via the angiotensin-converting enzyme 2 (ACE2) receptor-as such, an individual's susceptibility to COVID-19 increases alongside the upregulation of this receptor. COVID-19 has also been associated with interstitial pulmonary fibrosis, which leads to acute respiratory distress, cardiomyopathy, and shock. These outcomes are thought to result from imbalances in angiotensin (Ang) II and Ang-(1-7)/alamandine activity. ACE2, Ang-(1-7), and alamandine have potent anti-inflammatory properties, and some SARS-CoV-2 patients exhibit high levels of ACE2 and Ang-(1-7). This phenomenon could indicate a failing physiological response to prevent or reduce the severity of inflammation-mediated pulmonary injuries. Alamandine, which is another protective component of the RAS, has several health benefits owing to its antithrombogenic, anti-inflammatory, and antifibrotic characteristics. Alamandine alleviates pulmonary fibrosis via the Mas-related G protein-coupled receptor D (MrgD). Thus, a better understanding of this pathway could uncover novel pharmacological strategies for altering proinflammatory environments within the body. Following such strategies could inhibit fibrosis after SARS-CoV-2 infection and, consequently, prevent COVID-19.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Oligopeptides/therapeutic use , Angiotensin I/metabolism , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , COVID-19/metabolism , Humans , Peptide Fragments/metabolism , Renin-Angiotensin System/drug effects
10.
Int J Mol Sci ; 22(23)2021 Nov 26.
Article in English | MEDLINE | ID: covidwho-1542583

ABSTRACT

Alternative branches of the classical renin-angiotensin-aldosterone system (RAS) represent an important cascade in which angiotensin 2 (AngII) undergoes cleavage via the action of the angiotensin-converting enzyme 2 (ACE2) with subsequent production of Ang(1-7) and other related metabolites eliciting its effects via Mas receptor activation. Generally, this branch of the RAS system is described as its non-canonical alternative arm with counterbalancing actions to the classical RAS, conveying vasodilation, anti-inflammatory, anti-remodeling and anti-proliferative effects. The implication of this branch was proposed for many different diseases, ranging from acute cardiovascular conditions, through chronic respiratory diseases to cancer, nonetheless, hypoxia is one of the most prominent common factors discussed in conjugation with the changes in the activity of alternative RAS branches. The aim of this review is to bring complex insights into the mechanisms behind the various forms of hypoxic insults on the activity of alternative RAS branches based on the different duration of stimuli and causes (acute vs. intermittent vs. chronic), localization and tissue (heart vs. vessels vs. lungs) and clinical relevance of studied phenomenon (experimental vs. clinical condition). Moreover, we provide novel insights into the future strategies utilizing the alternative RAS as a diagnostic tool as well as a promising pharmacological target in serious hypoxia-associated cardiovascular and cardiopulmonary diseases.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19 , Hypoxia/metabolism , Myocardial Infarction , Renin-Angiotensin System , Angiotensin I , Angiotensin II/metabolism , Animals , Humans , Lung , Peptide Fragments , SARS-CoV-2
11.
Sovrem Tekhnologii Med ; 12(6): 98-108, 2021.
Article in English | MEDLINE | ID: covidwho-1527052

ABSTRACT

The rapidly accumulating information about the new coronavirus infection and the ambiguous results obtained by various authors necessitate further research aiming at prevention and treatment of this disease. At the moment, there is convincing evidence that the pathogen affects not only the respiratory but also the central nervous system (CNS). The aim of the study is to provide an insight into the molecular mechanisms underlying the damage to the CNS caused by the new coronavirus SARS-CoV-2. Results: By analyzing the literature, we provide evidence that the brain is targeted by this virus. SARS-CoV-2 enters the body with the help of the target proteins: angiotensin-converting enzyme 2 (ACE2) and associated serine protease TMPRSS2 of the nasal epithelium. Brain damage develops before the onset of pulmonary symptoms. The virus spreads through the brain tissue into the piriform cortex, basal ganglia, midbrain, and hypothalamus. Later, the substantia nigra of the midbrain, amygdala, hippocampus, and cerebellum become affected. Massive death of neurons, astrogliosis and activation of microglia develop at the next stage of the disease. By day 4, an excessive production of proinflammatory cytokines in the brain, local neuroinflammation, breakdown of the blood-brain barrier, and impaired neuroplasticity are detected. These changes imply the involvement of a vascular component driven by excessive activity of matrix metalloproteinases, mediated by CD147. The main players in the pathogenesis of COVID-19 in the brain are products of angiotensin II (AT II) metabolism, largely angiotensin 1-7 (AT 1-7) and angiotensin IV (AT IV). There are conflicting data regarding their role in damage to the CNS in various diseases, including the coronavirus infection.The second participant in the pathogenesis of brain damage in COVID-19 is CD147 - the inducer of extracellular matrix metalloproteinases. This molecule is expressed on the endothelial cells of cerebral microvessels, as well as on leukocytes present in the brain during neuroinflammation. The CD147 molecule plays a significant role in maintaining the structural and functional integrity of the blood-brain barrier by controlling the basal membrane permeability and by mediating the astrocyte-endothelial interactions. Via the above mechanisms, an exposure to SARS-CoV-2 leads to direct damage to the neurovascular unit of the brain.


Subject(s)
Astrocytes/metabolism , Brain/metabolism , COVID-19/metabolism , SARS-CoV-2/metabolism , Angiotensin I/metabolism , Angiotensin II/analogs & derivatives , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Basigin , Humans , Peptide Fragments/metabolism , Serine Endopeptidases/metabolism
12.
Biosci Rep ; 41(12)2021 12 22.
Article in English | MEDLINE | ID: covidwho-1506391

ABSTRACT

The angiotensin-converting enzyme (ACE)/Angiotensin II (Ang II) and angiotensin-converting enzyme 2 (ACE2)/angiotensin-(1-7) (Ang-(1-7)) pathways are coexpressed in most tissues. The balance between these pathways determines, at least in part, whether tissue damage will occur in response to pathological stimuli. The present study tested the hypothesis that male sex and high blood pressure are associated with ACE/ACE2 imbalance in the lungs. Experiments were conducted in male and female Wistar rats and spontaneously hypertensive rats (SHRs). Lung ACE and ACE2 gene expression was also evaluated in normotensive and hypertensive humans using the Genotype-Tissue Expression (GTEx) project. Compared with Wistar rats and female SHRs, male SHRs displayed reduced lung ACE2 mRNA, ACE2 protein abundance and ACE2 activity, and increased Ang II concentration. Lung ACE mRNA levels were higher in male SHRs than in Wistar rats, whereas lung ACE protein abundance and activity were similar among the four groups of rats. Lung Ang-(1-7) concentration was higher in female than in male SHRs (89 ± 17 vs. 43 ± 2 pg/g, P<0.05). Lung ACE to ACE2 mRNA expression in hypertensive patients was significantly higher than that in normotensive subjects. Taken together, these results demonstrate that male hypertensive rats display imbalance between the ACE/Ang II and ACE2/Ang-(1-7) pathways in the lungs mainly attributable to ACE2 down-regulation. Further studies should be conducted to investigate whether this imbalance between ACE/ACE2 may promote and accelerate lung injury in respiratory infections, including coronavirus disease 2019 (COVID-19).


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Lung/metabolism , Peptidyl-Dipeptidase A/metabolism , ADAM17 Protein/metabolism , Angiotensin I/metabolism , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/genetics , Animals , Down-Regulation , Female , Male , Peptide Fragments/metabolism , Peptidyl-Dipeptidase A/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred SHR , Rats, Wistar , Sex Characteristics
13.
Viruses ; 13(10)2021 09 23.
Article in English | MEDLINE | ID: covidwho-1438740

ABSTRACT

BACKGROUND: In healthy pregnancies, components of the Renin-Angiotensin system (RAS) are present in the placental villi and contribute to invasion, migration, and angiogenesis. At the same time, soluble fms-like tyrosine kinase 1 (sFlt-1) production is induced after binding of ANG-II to its receptor (AT-1R) in response to hypoxia. As RAS plays an essential role in the pathogenesis of COVID-19, we hypothesized that angiogenic marker (sFlt-1) and RAS components (ANG-II and ACE-2) may be related to adverse outcomes in pregnant women with COVID-19; Methods: Prospective cohort study. Primary outcome was severe pneumonia. Secondary outcomes were ICU admission, intubation, sepsis, and death. Spearman's Rho test was used to analyze the correlation between sFlt-1 and ANG-II levels. The sFlt-1/ANG-II ratio was determined and the association with each adverse outcome was explored by logistic regression analysis and the prediction was assessed using receiver-operating-curve (ROC); Results: Among 80 pregnant women with COVID-19, the sFlt-1/ANG-II ratio was associated with an increased probability of severe pneumonia (odds ratio [OR]: 1.31; p = 0.003), ICU admission (OR: 1.05; p = 0.007); intubation (OR: 1.09; p = 0.008); sepsis (OR: 1.04; p = 0.008); and death (OR: 1.04; p = 0.018); Conclusion: sFlt-1/ANG-II ratio is a good predictor of adverse events such as pneumonia, ICU admission, intubation, sepsis, and death in pregnant women with COVID-19.


Subject(s)
Angiotensin II/metabolism , COVID-19/metabolism , Vascular Endothelial Growth Factor Receptor-1/metabolism , Adult , Angiotensin II/analysis , Angiotensin II/physiology , Biomarkers , COVID-19/complications , Cohort Studies , Critical Illness , Female , Humans , Mexico/epidemiology , Placenta/metabolism , Pre-Eclampsia , Pregnancy , Pregnant Women , Prospective Studies , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Vascular Endothelial Growth Factor Receptor-1/analysis , Vascular Endothelial Growth Factor Receptor-1/physiology
17.
Biomolecules ; 11(7)2021 07 03.
Article in English | MEDLINE | ID: covidwho-1295754

ABSTRACT

Angiotensin II (Ang II) may contain a charge relay system (CRS) involving Tyr/His/carboxylate, which creates a tyrosinate anion for receptor activation. Energy calculations were carried out to determine the preferred geometry for the CRS in the presence and absence of the Arg guanidino group occupying position 2 of Ang II. These findings suggest that Tyr is preferred over His for bearing the negative charge and that the CRS is stabilized by the guanidino group. Recent crystallography studies provided details of the binding of nonpeptide angiotensin receptor blockers (ARBs) to the Ang II type 1 (AT1) receptor, and these insights were applied to Ang II. A model of binding and receptor activation that explains the surmountable and insurmountable effects of Ang II analogues sarmesin and sarilesin, respectively, was developed and enabled the discovery of a new generation of ARBs called bisartans. Finally, we determined the ability of the bisartan BV6(TFA) to act as a potential ARB, demonstrating similar effects to candesartan, by reducing vasoconstriction of rabbit iliac arteries in response to cumulative doses of Ang II. Recent clinical studies have shown that Ang II receptor blockers have protective effects in hypertensive patients infected with SARS-CoV-2. Therefore, the usage of ARBS to block the AT1 receptor preventing the binding of toxic angiotensin implicated in the storm of cytokines in SARS-CoV-2 is a target treatment and opens new avenues for disease therapy.


Subject(s)
Angiotensin II/metabolism , Angiotensin Receptor Antagonists/chemistry , Angiotensin Receptor Antagonists/pharmacology , COVID-19/drug therapy , Drug Discovery , Receptor, Angiotensin, Type 1/metabolism , Angiotensin II/analogs & derivatives , Animals , COVID-19/metabolism , Crystallography, X-Ray , Humans , Hypertension/drug therapy , Hypertension/metabolism , Male , Models, Molecular , Rabbits , Receptor, Angiotensin, Type 1/chemistry , Vasoconstriction/drug effects
18.
Front Immunol ; 12: 649122, 2021.
Article in English | MEDLINE | ID: covidwho-1285287

ABSTRACT

Thromboplasminflammation in coronavirus disease 2019 (COVID-19) coagulopathy consists of angiotensin II (Ang II)-induced coagulopathy, activated factor XII (FXIIa)- and kallikrein, kinin system-enhanced fibrinolysis, and disseminated intravascular coagulation (DIC). All three conditions induce systemic inflammation via each pathomechanism-developed production of inflammatory cytokines. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) downregulates angiotensin-converting enzyme 2, leading to an increase in Ang II levels. Ang II-induced coagulopathy comprising platelet activation, thrombin generation, plasminogen activator inhibitor-1 expression and endothelial injury causes thrombosis via the angiotensin II type 1 receptor. SARS-CoV-2 RNA and neutrophil extracellular trap (NET) DNA activate FXII, resulting in plasmin generation through FXIIa- and kallikrein-mediated plasminogen conversion to plasmin and bradykinin-induced tissue-type plasminogen activator release from the endothelium via the kinin B2 receptor. NETs induce immunothrombosis at the site of infection (lungs), through histone- and DNA-mediated thrombin generation, insufficient anticoagulation control, and inhibition of fibrinolysis. However, if the infection is sufficiently severe, immunothrombosis disseminates into the systemic circulation, and DIC, which is associated with the endothelial injury, occurs. Inflammation, and serine protease networks of coagulation and fibrinolysis, militate each other through complement pathways, which exacerbates three pathologies of COVID-19 coagulopathy. COVID-19 coagulopathy causes microvascular thrombosis and bleeding, resulting in multiple organ dysfunction and death in critically ill patients. Treatment targets for improving the prognosis of COVID-19 coagulopathy include thrombin, plasmin, and inflammation, and SARS-CoV-2 infection. Several drugs are candidates for controlling these conditions; however, further advances are required to establish robust treatments based on a clear understanding of molecular mechanisms of COVID-19 coagulopathy.


Subject(s)
Blood Coagulation Disorders/metabolism , COVID-19/metabolism , SARS-CoV-2/physiology , Angiotensin II/metabolism , Animals , Blood Coagulation Disorders/immunology , COVID-19/immunology , Cytokines/metabolism , Factor XIIa/metabolism , Humans , Inflammation , Inflammation Mediators/metabolism
19.
Nat Commun ; 12(1): 2417, 2021 04 23.
Article in English | MEDLINE | ID: covidwho-1203428

ABSTRACT

SARS-CoV-2 uses ACE2, an inhibitor of the Renin-Angiotensin-Aldosterone System (RAAS), for cellular entry. Studies indicate that RAAS imbalance worsens the prognosis in COVID-19. We present a consecutive retrospective COVID-19 cohort with findings of frequent pulmonary thromboembolism (17%), high pulmonary artery pressure (60%) and lung MRI perfusion disturbances. We demonstrate, in swine, that infusing angiotensin II or blocking ACE2 induces increased pulmonary artery pressure, reduces blood oxygenation, increases coagulation, disturbs lung perfusion, induces diffuse alveolar damage, and acute tubular necrosis compared to control animals. We further demonstrate that this imbalanced state can be ameliorated by infusion of an angiotensin receptor blocker and low-molecular-weight heparin. In this work, we show that a pathophysiological state in swine induced by RAAS imbalance shares several features with the clinical COVID-19 presentation. Therefore, we propose that severe COVID-19 could partially be driven by a RAAS imbalance.


Subject(s)
COVID-19/physiopathology , Lung/physiopathology , Renin-Angiotensin System/physiology , SARS-CoV-2/isolation & purification , Angiotensin II/administration & dosage , Angiotensin II/metabolism , Angiotensin Receptor Antagonists/administration & dosage , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/metabolism , COVID-19/virology , Female , Humans , Lung/diagnostic imaging , Lung/virology , Magnetic Resonance Imaging/methods , Protein Binding/drug effects , Retrospective Studies , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Swine , Virus Internalization/drug effects
20.
Drug Discov Today ; 26(10): 2214-2220, 2021 10.
Article in English | MEDLINE | ID: covidwho-1184927

ABSTRACT

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells by interacting with membrane-bound angiotensin-converting enzyme 2 (ACE2), a vital element in the renin-angiotensin system (RAS), which regulates blood pressure, fluid balance, and cardiovascular functions. We herein evaluate existing evidence for the molecular alterations within the RAS pathway (e.g., ACE2 and angiotensin II) during SARS-CoV-2 infection and subsequent Coronavirus Disease 2019 (COVID-19). This includes reports regarding potential effect of RAS blockade (e.g., ACE inhibitors and angiotensin II receptor blockers) on ACE2 expression and clinical outcomes in patients with co-morbidities commonly treated with these agents. The collective evidence suggests a dual role for ACE2 in COVID-19, depending on the stage of infection and the coexisting diseases in individual patients. This information is further discussed with respect to potential therapeutic strategies targeting RAS for COVID-19 treatment.


Subject(s)
COVID-19/therapy , Renin-Angiotensin System/drug effects , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2/genetics , COVID-19/drug therapy , COVID-19/physiopathology , Humans , SARS-CoV-2
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