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1.
Front Immunol ; 13: 835686, 2022.
Article in English | MEDLINE | ID: covidwho-1742218

ABSTRACT

Angiotensin converting enzyme-2 (ACE2) and associated proteins play a pivotal role in various physiological and pathological events, such as immune activation, inflammation, gut barrier maintenance, intestinal stem cell proliferation, and apoptosis. Although many of these clinical events are quite significant in SIV/HIV infection, expression profiling of these proteins has not been well reported. Considering the different pathological consequences in the gut after HIV infection, we hypothesized that the expression of ACE2 and associated proteins of the Renin-angiotensin system (RAS) could be compromised after SIV/HIV infection. We quantified the gene expression of ACE2 as well as AGTR1/2, ADAM17, and TMPRSS2, and compared between SIV infected and uninfected rhesus macaques (Macaca mulatta; hereafter abbreviated RMs). The gene expression analysis revealed significant downregulation of ACE2 and upregulation of AGTR2 and inflammatory cytokine IL-6 in the gut of infected RMs. Protein expression profiling also revealed significant upregulation of AGTR2 after infection. The expression of ACE2 in protein level was also decreased, but not significantly, after infection. To understand the entirety of the process in newly regenerated epithelial cells, a global transcriptomic study of enteroids raised from intestinal stem cells was performed. Interestingly, most of the genes associated with the RAS, such as DPP4, MME, ANPEP, ACE2, ENPEP, were found to be downregulated in SIV infection. HNFA1 was found to be a key regulator of ACE2 and related protein expression. Jejunum CD4+ T cell depletion and increased IL-6 mRNA, MCP-1 and AGTR2 expression may signal inflammation, monocyte/macrophage accumulation and epithelial apoptosis in accelerating SIV pathogenesis. Overall, the findings in the study suggested a possible impact of SIV/HIV infection on expression of ACE2 and RAS-associated proteins resulting in the loss of gut homeostasis. In the context of the current COVID-19 pandemic, the outcome of SARS-CoV-2 and HIV co-infection remains uncertain and needs further investigation as the significance profile of ACE2, a viral entry receptor for SARS-CoV-2, and its expression in mRNA and protein varied in the current study. There is a concern of aggravated SARS-CoV-2 outcomes due to possible serious pathological events in the gut resulting from compromised expression of RAS- associated proteins in SIV/HIV infection.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , CD4-Positive T-Lymphocytes/immunology , Jejunum/metabolism , Simian Acquired Immunodeficiency Syndrome/metabolism , Simian Immunodeficiency Virus/physiology , Animals , Cells, Cultured , Cytokines/metabolism , Dipeptidyl Peptidase 4/metabolism , Gene Expression Regulation , Humans , Inflammation Mediators , Jejunum/pathology , Macaca mulatta , Receptor, Angiotensin, Type 2/metabolism
2.
J Vet Sci ; 22(1): e12, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-1389650

ABSTRACT

BACKGROUND: Bats have been considered natural reservoirs for several pathogenic human coronaviruses (CoVs) in the last two decades. Recently, a bat CoV was detected in the Republic of Korea; its entire genome was sequenced and reported to be genetically similar to that of the severe acute respiratory syndrome CoV (SARS-CoV). OBJECTIVES: The objective of this study was to compare the genetic sequences of SARS-CoV, SARS-CoV-2, and the two Korean bat CoV strains 16BO133 and B15-21, to estimate the likelihood of an interaction between the Korean bat CoVs and the human angiotensin-converting enzyme 2 (ACE2) receptor. METHODS: The phylogenetic analysis was conducted with the maximum-likelihood (ML) method using MEGA 7 software. The Korean bat CoVs receptor binding domain (RBD) of the spike protein was analyzed by comparative homology modeling using the SWISS-MODEL server. The binding energies of the complexes were calculated using PRODIGY and MM/GBGA. RESULTS: Phylogenetic analyses of the entire RNA-dependent RNA polymerase, spike regions, and the complete genome revealed that the Korean CoVs, along with SARS-CoV and SARS-CoV-2, belong to the subgenus Sarbecovirus, within BetaCoVs. However, the two Korean CoVs were distinct from SARS-CoV-2. Specifically, the spike gene of the Korean CoVs, which is involved in host infection, differed from that of SARS-CoV-2, showing only 66.8%-67.0% nucleotide homology and presented deletions within the RBD, particularly within regions critical for cross-species transmission and that mediate interaction with ACE2. Binding free energy calculation revealed that the binding affinity of Korean bat CoV RBD to hACE2 was drastically lower than that of SARS-CoV and SARS-CoV-2. CONCLUSIONS: These results suggest that Korean bat CoVs are unlikely to bind to the human ACE2 receptor.


Subject(s)
Chiroptera/virology , Coronavirus/genetics , SARS Virus/genetics , SARS-CoV-2/genetics , Animals , Genes, Viral/genetics , Genome, Viral/genetics , Genomics , Humans , Likelihood Functions , Phylogeny , Receptor, Angiotensin, Type 2/genetics , Receptor, Angiotensin, Type 2/metabolism , Republic of Korea , Sequence Analysis, DNA , Sequence Homology , Spike Glycoprotein, Coronavirus/genetics , Virus Attachment
4.
Respir Res ; 22(1): 164, 2021 May 29.
Article in English | MEDLINE | ID: covidwho-1247590

ABSTRACT

BACKGROUND: Chronic obstructive pulmonary disease (COPD) patients are at increased risk of poor outcome from Coronavirus disease (COVID-19). Early data suggest elevated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) receptor angiotensin converting enzyme 2 (ACE2) expression, but relationships to disease phenotype and downstream regulators of inflammation in the Renin-Angiotensin system (RAS) are unknown. We aimed to determine the relationship between RAS gene expression relevant to SARS-CoV-2 infection in the lung with disease characteristics in COPD, and the regulation of newly identified SARS-CoV-2 receptors and spike-cleaving proteases, important for SARS-CoV-2 infection. METHODS: We quantified gene expression using RNA sequencing of epithelial brushings and bronchial biopsies from 31 COPD and 37 control subjects. RESULTS: ACE2 gene expression (log2-fold change (FC)) was increased in COPD compared to ex-smoking (HV-ES) controls in epithelial brushings (0.25, p = 0.042) and bronchial biopsies (0.23, p = 0.050), and correlated with worse lung function (r = - 0.28, p = 0.0090). ACE2 was further increased in frequent exacerbators compared to infrequent exacerbators (0.51, p = 0.00045) and associated with use of ACE inhibitors (ACEi) (0.50, p = 0.0034), having cardiovascular disease (0.23, p = 0.048) or hypertension (0.34, p = 0.0089), and inhaled corticosteroid use in COPD subjects in bronchial biopsies (0.33, p = 0.049). Angiotensin II receptor type (AGTR)1 and 2 expression was decreased in COPD bronchial biopsies compared to HV-ES controls with log2FC of -0.26 (p = 0.033) and - 0.40, (p = 0.0010), respectively. However, the AGTR1:2 ratio was increased in COPD subjects compared with HV-ES controls, log2FC of 0.57 (p = 0.0051). Basigin, a newly identified potential SARS-CoV-2 receptor was also upregulated in both brushes, log2FC of 0.17 (p = 0.0040), and bronchial biopsies, (log2FC of 0.18 (p = 0.017), in COPD vs HV-ES. Transmembrane protease, serine (TMPRSS)2 was not differentially regulated between control and COPD. However, various other spike-cleaving proteases were, including TMPRSS4 and Cathepsin B, in both epithelial brushes (log2FC of 0.25 (p = 0.0012) and log2FC of 0.56 (p = 5.49E-06), respectively) and bronchial biopsies (log2FC of 0.49 (p = 0.00021) and log2FC of 0.246 (p = 0.028), respectively). CONCLUSION: This study identifies key differences in expression of genes related to susceptibility and aetiology of COVID-19 within the COPD lung. Further studies to understand the impact on clinical course of disease are now required.


Subject(s)
COVID-19/genetics , Lung/metabolism , Pulmonary Disease, Chronic Obstructive/genetics , Transcriptome , Aged , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Basigin/genetics , Basigin/metabolism , COVID-19/diagnosis , COVID-19/metabolism , COVID-19/physiopathology , Case-Control Studies , Female , Forced Expiratory Volume , Gene Expression Regulation , Humans , Lung/physiopathology , Male , Middle Aged , Prognosis , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Disease, Chronic Obstructive/physiopathology , Receptor, Angiotensin, Type 1/genetics , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/genetics , Receptor, Angiotensin, Type 2/metabolism , Vital Capacity
5.
Hypertension ; 77(6): 1845-1856, 2021 06.
Article in English | MEDLINE | ID: covidwho-1177625

ABSTRACT

The renin-angiotensin system is of vital significance not only in the maintenance of blood pressure but also because of its role in the pathophysiology of different organ systems in the body. Of the 2 Ang II (angiotensin II) receptors, the AT1R (Ang II type 1 receptor) has been extensively studied for its role in mediating the classical functions of Ang II, including vasoconstriction, stimulation of renal tubular sodium reabsorption, hormonal secretion, cell proliferation, inflammation, and oxidative stress. The other receptor, AT2R (Ang II type 2 receptor), is abundantly expressed in both immune and nonimmune cells in fetal tissue. However, its expression is increased under pathological conditions in adult tissues. The role of AT2R in counteracting AT1R function has been discussed in the past 2 decades. However, with the discovery of the nonpeptide agonist C21, the significance of AT2R in various pathologies such as obesity, hypertension, and kidney diseases have been examined. This review focuses on the most recent findings on the beneficial effects of AT2R by summarizing both gene knockout studies as well as pharmacological studies, specifically highlighting its importance in blood pressure regulation, obesity/metabolism, organ protection, and relevance in the treatment of coronavirus disease 2019 (COVID-19).


Subject(s)
Hypertension , Receptor, Angiotensin, Type 2/metabolism , Renin-Angiotensin System , Animals , Blood Pressure/drug effects , Blood Pressure/immunology , COVID-19/drug therapy , COVID-19/epidemiology , COVID-19/metabolism , Humans , Hypertension/drug therapy , Hypertension/metabolism , Hypertension/physiopathology , Pharmacological Phenomena , Renin-Angiotensin System/drug effects , Renin-Angiotensin System/physiology
6.
Scand J Immunol ; 93(6): e13043, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1158095

ABSTRACT

Coronavirus infections are frequent viral infections in several species. As soon as the severe acute respiratory syndrome (SARS) appeared in the early 2000s, most of the research focused on pulmonary disease. However, disorders in immune response and organ dysfunctions have been documented. Elderly individuals with comorbidities exhibit worse outcomes in all the coronavirus that cause SARS. Disease severity in SARS-CoV-2 infection is related to severe inflammation and tissue injury, and effective immune response against the virus is still under analysis. ACE2 receptor expression and polymorphism, age, gender and immune genetics are factors that also play an essential role in patients' clinical features and immune responses and have been partially discussed. The present report aims to review the physiopathology of SARS-CoV-2 infection and propose new research topics to understand the complex mechanisms of viral infection and viral clearance.


Subject(s)
COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions/immunology , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Biomarkers , COVID-19/complications , COVID-19/metabolism , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/metabolism , Cytokines/metabolism , Disease Susceptibility/immunology , Energy Metabolism , Humans , Immunity, Innate , Inflammation Mediators/metabolism , Lymphocyte Subsets/immunology , Lymphocyte Subsets/metabolism , Receptor, Angiotensin, Type 2/metabolism , Receptors, Virus/metabolism , Virus Replication
7.
Vascul Pharmacol ; 138: 106856, 2021 06.
Article in English | MEDLINE | ID: covidwho-1144979

ABSTRACT

COVID-19, a global-pandemic binds human-lung-ACE2. ACE2 causes vasodilatation. ACE2 works in balance with ACE1. The vaso-status maintains blood-pressure/vascular-health which is demolished in Covid-19 manifesting aldosterone/salt-deregulations/inflammations/endothelial-dysfunctions/hyper-hypo- tension, sepsis/hypovolemic-shock and vessel-thrombosis/coagulations. Here, nigellidine, an indazole-alkaloid was analyzed by molecular-docking for binding to different Angiotensin-binding-proteins (enzymes, ACE1(6en5)/ACE2(4aph)/receptors, AT1(6os1)/AT2(5xjm)) and COVID-19 spike-glycoprotein(6vsb). Nigellidine strongly binds to the spike-protein at the hinge-region/active-site-opening which may hamper proper-binding of nCoV2-ACE2 surface. Nigellidine effectively binds in the Angiotensin- II binding-site/entry-pocket (-7.54 kcal/mol, -211.76, Atomic-Contact-Energy; ACE-value) of ACE2 (Ki 8.68 and 8.3 µmol) in comparison to known-binder EGCG (-4.53) and Theaflavin-di-gallate (-2.85). Nigellidine showed strong-binding (Ki, 50.93 µmol/binding-energy -5.48 kcal/mol) to mono/multi-meric ACE1. Moreover, it binds Angiotensin-receptors, AT1/AT2 (Ki, 42.79/14.22 µmol, binding-energy, -5.96/-6.61 kcal/mol) at active-sites, respectively. This article reports the novel binding of nigellidine and subsequent blockage of angiotensin-binding proteins. The ACEs-blocking could restore Angiotensin-level, restrict vaso-turbulence in Covid patients and receptor-blocking might stop inflammatory/vascular impairment. Nigellidine may slowdown the vaso-fluctuations due to Angiotensin-deregulations in Covid patients. Angiotensin II-ACE2 binding (ACE-value -294.81) is more favorable than nigellidine-ACE2. Conversely, nigellidine-ACE1 binding-energy/Ki is lower than nigellidine-ACE2 values indicating a balanced-state between constriction-dilatation. Moreover, nigellidine binds to the viral-spike, closer-proximity to its ACE2 binding-domain. Taken together, Covid patients/elderly-patients, comorbid-patients (with hypertensive/diabetic/cardiac/renal-impairment, counting >80% of non-survivors) could be greatly benefited.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Nigella sativa , Peptidyl-Dipeptidase A/metabolism , Plant Extracts/metabolism , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/metabolism , Angiotensin-Converting Enzyme 2/chemistry , COVID-19/pathology , COVID-19/prevention & control , Comorbidity , Computer Simulation/trends , Drug Evaluation, Preclinical/methods , Humans , Molecular Docking Simulation/methods , Peptidyl-Dipeptidase A/chemistry , Plant Extracts/isolation & purification , Plant Extracts/therapeutic use , Protein Binding/physiology , Protein Structure, Secondary , Protein Structure, Tertiary , Receptor, Angiotensin, Type 1/chemistry , Receptor, Angiotensin, Type 2/chemistry , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism
8.
J Vet Sci ; 22(1): e12, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-1058564

ABSTRACT

BACKGROUND: Bats have been considered natural reservoirs for several pathogenic human coronaviruses (CoVs) in the last two decades. Recently, a bat CoV was detected in the Republic of Korea; its entire genome was sequenced and reported to be genetically similar to that of the severe acute respiratory syndrome CoV (SARS-CoV). OBJECTIVES: The objective of this study was to compare the genetic sequences of SARS-CoV, SARS-CoV-2, and the two Korean bat CoV strains 16BO133 and B15-21, to estimate the likelihood of an interaction between the Korean bat CoVs and the human angiotensin-converting enzyme 2 (ACE2) receptor. METHODS: The phylogenetic analysis was conducted with the maximum-likelihood (ML) method using MEGA 7 software. The Korean bat CoVs receptor binding domain (RBD) of the spike protein was analyzed by comparative homology modeling using the SWISS-MODEL server. The binding energies of the complexes were calculated using PRODIGY and MM/GBGA. RESULTS: Phylogenetic analyses of the entire RNA-dependent RNA polymerase, spike regions, and the complete genome revealed that the Korean CoVs, along with SARS-CoV and SARS-CoV-2, belong to the subgenus Sarbecovirus, within BetaCoVs. However, the two Korean CoVs were distinct from SARS-CoV-2. Specifically, the spike gene of the Korean CoVs, which is involved in host infection, differed from that of SARS-CoV-2, showing only 66.8%-67.0% nucleotide homology and presented deletions within the RBD, particularly within regions critical for cross-species transmission and that mediate interaction with ACE2. Binding free energy calculation revealed that the binding affinity of Korean bat CoV RBD to hACE2 was drastically lower than that of SARS-CoV and SARS-CoV-2. CONCLUSIONS: These results suggest that Korean bat CoVs are unlikely to bind to the human ACE2 receptor.


Subject(s)
Chiroptera/virology , Coronavirus/genetics , SARS Virus/genetics , SARS-CoV-2/genetics , Animals , Genes, Viral/genetics , Genome, Viral/genetics , Genomics , Humans , Likelihood Functions , Phylogeny , Receptor, Angiotensin, Type 2/genetics , Receptor, Angiotensin, Type 2/metabolism , Republic of Korea , Sequence Analysis, DNA , Sequence Homology , Spike Glycoprotein, Coronavirus/genetics , Virus Attachment
9.
Clin Sci (Lond) ; 135(2): 387-407, 2021 01 29.
Article in English | MEDLINE | ID: covidwho-1054073

ABSTRACT

The two axes of the renin-angiotensin system include the classical ACE/Ang II/AT1 axis and the counter-regulatory ACE2/Ang-(1-7)/Mas1 axis. ACE2 is a multifunctional monocarboxypeptidase responsible for generating Ang-(1-7) from Ang II. ACE2 is important in the vascular system where it is found in arterial and venous endothelial cells and arterial smooth muscle cells in many vascular beds. Among the best characterized functions of ACE2 is its role in regulating vascular tone. ACE2 through its effector peptide Ang-(1-7) and receptor Mas1 induces vasodilation and attenuates Ang II-induced vasoconstriction. In endothelial cells activation of the ACE2/Ang-(1-7)/Mas1 axis increases production of the vasodilator's nitric oxide and prostacyclin's and in vascular smooth muscle cells it inhibits pro-contractile and pro-inflammatory signaling. Endothelial ACE2 is cleaved by proteases, shed into the circulation and measured as soluble ACE2. Plasma ACE2 activity is increased in cardiovascular disease and may have prognostic significance in disease severity. In addition to its enzymatic function, ACE2 is the receptor for severe acute respiratory syndrome (SARS)-coronavirus (CoV) and SARS-Cov-2, which cause SARS and coronavirus disease-19 (COVID-19) respectively. ACE-2 is thus a double-edged sword: it promotes cardiovascular health while also facilitating the devastations caused by coronaviruses. COVID-19 is associated with cardiovascular disease as a risk factor and as a complication. Mechanisms linking COVID-19 and cardiovascular disease are unclear, but vascular ACE2 may be important. This review focuses on the vascular biology and (patho)physiology of ACE2 in cardiovascular health and disease and briefly discusses the role of vascular ACE2 as a potential mediator of vascular injury in COVID-19.


Subject(s)
Angiotensin I/metabolism , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Peptide Fragments/metabolism , Proto-Oncogene Proteins/metabolism , Receptors, G-Protein-Coupled/metabolism , Vascular Diseases/virology , Animals , Blood Vessels/enzymology , Humans , Receptor, Angiotensin, Type 2/metabolism , Renin-Angiotensin System , SARS-CoV-2/metabolism , Vascular Diseases/metabolism
10.
Med Hypotheses ; 147: 110486, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1014720

ABSTRACT

On March 11, 2020 the World Health Organization (WHO) declared the state of global pandemic caused by the new SARS-CoV-2 (COVID-19). To date, no antivirals directed against SARS-CoV-2 or effective vaccines to combat the viral infection are available. Severe acute respiratory syndrome caused by SARS-CoV-2 is treated empirically with antivirals, anti-inflammatory, anticoagulants. The approval of an effective vaccine still takes time. In this state, it may be useful to find new therapeutic solutions from drugs already on the market. Recent hypotheses suggest that the use of AT-1 receptor antagonists (ARB) in combination with neprilisin inhibitors (NEPi) could indirectly provide clinical benefits to patients with SARS-CoV-2 and cardiac involvement. In this article we investigate and describe a possible innovative pharmacological approach for the treatment of the most severe stages of COVID-19 infection.


Subject(s)
Aminobutyrates/administration & dosage , COVID-19/drug therapy , Heart Failure/drug therapy , Tetrazoles/administration & dosage , Valsartan/administration & dosage , Angiotensin-Converting Enzyme Inhibitors , Antiviral Agents/therapeutic use , Biphenyl Compounds , Cytokine Release Syndrome/virology , Cytokines/metabolism , Drug Combinations , Heart Failure/virology , Homeostasis , Humans , Inflammation , Models, Theoretical , Natriuretic Peptide, Brain/metabolism , Neprilysin/adverse effects , Peptide Fragments/metabolism , Receptor, Angiotensin, Type 2/metabolism , World Health Organization
11.
Am J Med Sci ; 361(3): 287-296, 2021 03.
Article in English | MEDLINE | ID: covidwho-996602

ABSTRACT

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since it was first recognized in December 2019, it has resulted in the ongoing worldwide pandemic. Although acute hypoxic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) are the main features of the disease, the involvement of other organs needs to be explored. There has been a growing concern regarding the association between acute kidney injury (AKI) and poor outcomes in SARS-CoV-2 patients. Based on current observational data, AKI is the 2nd most common cause of morbidity and mortality behind ARDS in SARS-CoV-2 patients. Angiotensin-converting enzyme 2 (ACE2) receptor has been shown to be the cornerstone of SARS-CoV-2 infection and possibly plays a significant role in the occurrence of renal injury. The pathogenesis of AKI is likely multifactorial that involves not only direct viral invasion but also dysregulated immune response in the form of cytokine storm, ischemia to kidneys, hypercoagulable state, and rhabdomyolysis, among others. We performed a literature search of the Pubmed and Google Scholar database from 1996 to 2020 using the following keywords: severe acute respiratory syndrome coronavirus 2, coronavirus disease 2019, angiotensin-converting enzyme 2 receptor, and acute kidney injury to find the most pertinent and highest-quality of evidence. Any cited references were reviewed to identify relevant literature. The purpose of this review is to discuss, explore, and summarize the relationship between AKI in SARS-CoV-2 patients, with a focus on its epidemiology, association with ACE2 receptors, and pathophysiology of AKI.


Subject(s)
Acute Kidney Injury/etiology , COVID-19/complications , Receptor, Angiotensin, Type 2/metabolism , SARS-CoV-2 , Humans , Renin-Angiotensin System , Virus Internalization
12.
Bioessays ; 43(3): e2000112, 2021 03.
Article in English | MEDLINE | ID: covidwho-985954

ABSTRACT

This renin-angiotensin system (RAS) interpretation is focused on differences in tissue dependence on RAS and on the topological hierarchy that allows mediators to act only on downstream tissues. Dependence of tissues on RAS: Tested by expectation maximization clustering of the RNA human tissue expression (https://biogps.org/). ACE and vasoconstrictive AT1R clustered with the prorenin receptor. ACE2 and dilatory MAS1 clustered with nine RAS-related genes, highly expressed in: Liver; Cardiac_Myocytes; Skeletal_Muscle; Uterus; Kidney; Lung; Small_Intestine; Smooth_Muscle. RAS and stress accumulation: While prorenin is active after binding to its receptor, binding of soluble renin increases its enzymatic activity several times. Increased renin secretion multiplies the overall capacity for producing Ang I, leading to hypertension and increased vascular resistance. Coronavirus infection and comorbidities: Cardiorespiratory failure during infection is linked to the previously altered RAS role in lungs and myocardium. Reduced vasodilation by ACE2 lead to vasoconstriction and suboptimal tissue perfusion patterns. Also see the video abstract here https://www.youtube.com/watch?v=Jf0Iped-Mws.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/genetics , Hypertension/genetics , Renin-Angiotensin System/genetics , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Aged , Angiotensin I/genetics , Angiotensin I/metabolism , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , COVID-19/mortality , COVID-19/virology , Gene Expression Regulation , Humans , Hypertension/metabolism , Hypertension/mortality , Hypertension/virology , Lung/metabolism , Lung/pathology , Lung/virology , Myocardium/metabolism , Myocardium/pathology , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Receptor, Angiotensin, Type 1/genetics , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/genetics , Receptor, Angiotensin, Type 2/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Renin/genetics , Renin/metabolism , Signal Transduction , Survival Analysis
13.
Int J Mol Sci ; 21(24)2020 Dec 16.
Article in English | MEDLINE | ID: covidwho-993550

ABSTRACT

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 lead to minor alterations of signal transduction, ligand binding to AT1R and AT2R, but not to MasR, resulted in the 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.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , Receptors, CXCR4/metabolism , Receptors, Virus/metabolism , SARS-CoV-2/metabolism , Adult , Cell Line , Chemokine CXCL12/metabolism , HEK293 Cells , Humans , Peptidyl-Dipeptidase A/metabolism , Proto-Oncogene Proteins/metabolism , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/metabolism , Receptors, G-Protein-Coupled/metabolism , Renin-Angiotensin System/physiology , Signal Transduction/physiology
14.
Turk J Med Sci ; 50(SI-1): 638-657, 2020 04 21.
Article in English | MEDLINE | ID: covidwho-918263

ABSTRACT

COVID-19 caused by a novel agent SARS-CoV-2 progressed to a pandemic condition and resulted in a major public health concern worldwide, leading to social and economic issues at the same time. The pathogenesis of COVID-19 starts with the bonding of the virus to ACE2 receptors expressed in many tissues, and the triggered excessive immune response plays a critical role in the course of the disease. The cytokine storm that occurs upon excessive production of pro-inflammatory cytokines is considered responsible for the severe progression of the disease and the organ damage. However, the accurate pathophysiological mechanism of the disease, which progresses with various clinical presentations, is still substantially unknown. While various studies have been conducted on the effect of genetic polymorphism on the course and severity of the disease, the presence of a significant effect has not been proven yet. The clinical course of the disease is variable, with clinical representation ranging from 81% mild course to 14% severe course along with 5% critical course in patients. Asymptomatic course is considered to be higher than expected, although its frequency is not known exactly. Older adults and those with comorbidities are exposed to a more severe disease course. The disease progress with various symptoms, such as fever, cough, dyspnea, malaise, myalgia, taste and smell dysfunctions, diarrhea, and headache. A range of complications (acute respiratory distress syndrome, thromboembolic conditions, arrhythmia and cardiac events, secondary infections) could be seen during the course of the disease. Varied laboratory tests are vital to determine these verity and prognosis of the disease, along with the condition and exposure of the affected systems during thecourse of COVID-19.


Subject(s)
Betacoronavirus , Cardiovascular System , Coronavirus Infections , Digestive System , Lung , Pandemics , Pneumonia, Viral , Polymorphism, Genetic , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/pathology , Coronavirus Infections/physiopathology , Coronavirus Infections/virology , Cytokines/metabolism , Humans , Inflammation/etiology , Kidney , Nervous System , Pneumonia, Viral/complications , Pneumonia, Viral/pathology , Pneumonia, Viral/physiopathology , Pneumonia, Viral/virology , Receptor, Angiotensin, Type 2/metabolism , Respiratory Distress Syndrome/etiology , SARS-CoV-2
16.
Mol Med ; 26(1): 80, 2020 08 17.
Article in English | MEDLINE | ID: covidwho-717479

ABSTRACT

Infection of lung cells by the corona virus results in a loss of the balance between, on the one hand, angiotensin II-mediated stimulation of the angiotensin II type 1 receptor and, on the other hand, stimulation of the angiotensin II type 2 receptor and/or the Mas receptor. The unbalanced enhanced stimulation of the angiotensin II type 1 receptor causes inflammation, edema and contributes to the pathogenesis of severe acute respiratory distress syndrome. Here we hypothesize that stable, receptor-specific agonists of the angiotensin II type 2 receptor and of the Mas receptor are molecular medicines to treat COVID-19 patients. These agonists have therapeutic potential in the acute disease but in addition may reduce COVID-19-associated long-term pulmonary dysfunction and overall end-organ damage of this disease.


Subject(s)
Peptidyl-Dipeptidase A/metabolism , Receptor, Angiotensin, Type 2/agonists , Renin-Angiotensin System/drug effects , Angiotensin-Converting Enzyme 2 , Animals , COVID-19 , Clinical Trials as Topic , Coronavirus Infections/drug therapy , Humans , Imidazoles/pharmacology , Pandemics , Pneumonia, Viral/drug therapy , Receptor, Angiotensin, Type 2/metabolism , Renin-Angiotensin System/physiology
17.
J Immunol ; 205(5): 1198-1206, 2020 09 01.
Article in English | MEDLINE | ID: covidwho-654195

ABSTRACT

Fever in infections correlates with inflammation, macrophage infiltration into the affected organ, macrophage activation, and release of cytokines involved in immune response, hematopoiesis, and homeostatic processes. Angiotensin-converting enzyme 2 (ACE2) is the canonical cell surface receptor for SARS-CoV-2. ACE2 together with angiotensin receptor types 1 and 2 and ACE2 are components of the renin-angiotensin system (RAS). Exacerbated production of cytokines, mainly IL-6, points to macrophages as key to understand differential COVID-19 severity. SARS-CoV-2 may modulate macrophage-mediated inflammation events by altering the balance between angiotensin II, which activates angiotensin receptor types 1 and 2, and angiotensin 1-7 and alamandine, which activate MAS proto-oncogene and MAS-related D receptors, respectively. In addition to macrophages, lung cells express RAS components; also, some lung cells are able to produce IL-6. Addressing how SARS-CoV-2 unbalances RAS functionality via ACE2 will help design therapies to attenuate a COVID-19-related cytokine storm.


Subject(s)
Betacoronavirus/metabolism , Coronavirus Infections/immunology , Interleukin-6/biosynthesis , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/immunology , Renin-Angiotensin System , Angiotensin I/metabolism , Angiotensin-Converting Enzyme 2 , Animals , Betacoronavirus/immunology , COVID-19 , Coronavirus Infections/virology , Humans , Inflammation/immunology , Macrophages/immunology , Pandemics , Peptide Fragments/metabolism , Pneumonia, Viral/virology , Proto-Oncogene Proteins/metabolism , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, Virus/metabolism , SARS-CoV-2
18.
Med Hypotheses ; 143: 110091, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-642204

ABSTRACT

Breast cancer is the most common cancer in women and is the second most common cause of death in women. Estrogen plays an important role in breast tumor etiopathogenesis. Tamoxifen and other anti-estrogen drugs are used in breast cancer patients who have a positive estrogen receptor (ER). While angiotensin II plays a key role in breast cancer etiology and causes tamoxifen resistance, angiotensin 1-7 has been reported to may reduce the spread and invasion of breast cancer. During the COVID-19 infection, the virus blocks ACE2, and angiotensin 1-7 production discontinued. Angiotensin III production may increase as angiotensin II destruction is reduced. Thus, aminopeptidase upregulation may occur. Increased aminopeptidase may develop resistance to chemotherapy in breast cancer patients receiving chemotherapy. Estrogen can have a protective effect against COVID-19. Estrogen increase causes ER-α upregulation in T lymphocytes. Thus, estrogen increases the release of interferon I and III from T lymphocytes. Increasing interferon I and III alleviates COVID-19 infection. Tamoxifen treatment causes down-regulation, mutation, or loss in estrogen receptors. In the long-term use of tamoxifen, its effects on estrogen receptors can be permanent. Thus, since estrogen receptors are damaged or downregulated, estrogen may not act by binding to these receptors. Tamoxifen is a P-glycoprotein inhibitor, independent of its effect on estrogen receptors. It suppresses T cell functions and interferon release. We think tamoxifen may increase the COVID-19 risk due to its antiestrogen and P-glycoprotein inhibitory effects.


Subject(s)
Antineoplastic Agents/administration & dosage , Breast Neoplasms/drug therapy , Coronavirus Infections/complications , Drug Resistance, Neoplasm , Pneumonia, Viral/complications , Tamoxifen/administration & dosage , ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Betacoronavirus , Breast Neoplasms/complications , COVID-19 , Disease Susceptibility , Estrogen Antagonists/administration & dosage , Female , Humans , Interferons , Pandemics , Receptor, Angiotensin, Type 2/metabolism , Receptors, Estrogen/metabolism , Risk , SARS-CoV-2
20.
Inflamm Res ; 69(9): 825-839, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-593429

ABSTRACT

PURPOSE: Novel Coronavirus disease 2019 (COVID-19), is an acute respiratory distress syndrome (ARDS), which is emerged in Wuhan, and recently become worldwide pandemic. Strangely, ample evidences have been shown that the severity of COVID-19 infections varies widely from children (asymptomatic), adults (mild infection), as well as elderly adults (deadly critical). It has proven that COVID-19 infection in some elderly critical adults leads to a cytokine storm, which is characterized by severe systemic elevation of several pro-inflammatory cytokines. Then, a cytokine storm can induce edematous, ARDS, pneumonia, as well as multiple organ failure in aged patients. It is far from clear till now why cytokine storm induces in only COVID-19 elderly patients, and not in young patients. However, it seems that aging is associated with mild elevated levels of local and systemic pro-inflammatory cytokines, which is characterized by "inflamm-aging". It is highly likely that "inflamm-aging" is correlated to increased risk of a cytokine storm in some critical elderly patients with COVID-19 infection. METHODS: A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar pre-print database using all available MeSH terms for COVID-19, Coronavirus, SARS-CoV-2, senescent cell, cytokine storm, inflame-aging, ACE2 receptor, autophagy, and Vitamin D. Electronic database searches combined and duplicates were removed. RESULTS: The aim of the present review was to summarize experimental data and clinical observations that linked the pathophysiology mechanisms of "inflamm-aging", mild-grade inflammation, and cytokine storm in some elderly adults with severe COVID-19 infection.


Subject(s)
Aging , Coronavirus Infections/immunology , Coronavirus Infections/physiopathology , Cytokine Release Syndrome/virology , Inflammation/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/physiopathology , Adipocytes/cytology , Age Factors , Aged , Angiotensin II Type 2 Receptor Blockers/pharmacology , Autophagy , Betacoronavirus , COVID-19 , Cellular Senescence , Cytokines/immunology , Humans , Immune System , Inflammation/physiopathology , Pandemics , Reactive Oxygen Species/metabolism , Receptor, Angiotensin, Type 2/metabolism , SARS-CoV-2 , Vitamin D/metabolism , Vitamin D Deficiency
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