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1.
FASEB J ; 36(3): e22234, 2022 03.
Article in English | MEDLINE | ID: covidwho-1702985

ABSTRACT

The transmembrane protease angiotensin converting enzyme 2 (ACE2) is a protective regulator within the renin angiotensin system and additionally represents the cellular receptor for SARS-CoV. The release of soluble ACE2 (sACE2) from the cell surface is hence believed to be a crucial part of its (patho)physiological functions, as both, ACE2 protease activity and SARS-CoV binding ability, are transferred from the cell membrane to body fluids. Yet, the molecular sources of sACE2 are still not completely investigated. In this study, we show different sources and prerequisites for the release of sACE2 from the cell membrane. By using inhibitors as well as CRISPR/Cas9-derived cells, we demonstrated that, in addition to the metalloprotease ADAM17, also ADAM10 is an important novel shedding protease of ACE2. Moreover, we observed that ACE2 can also be released in extracellular vesicles. The degree of either ADAM10- or ADAM17-mediated ACE2 shedding is dependent on stimulatory conditions and on the expression level of the pro-inflammatory ADAM17 regulator iRhom2. Finally, by using structural analysis and in vitro verification, we determined for the first time that the susceptibility to ADAM10- and ADAM17-mediated shedding is mediated by the collectrin-like part of ACE2. Overall, our findings give novel insights into sACE2 release by several independent molecular mechanisms.


Subject(s)
ADAM10 Protein/metabolism , ADAM17 Protein/metabolism , Amyloid Precursor Protein Secretases/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Extracellular Vesicles/metabolism , Membrane Glycoproteins/metabolism , Membrane Proteins/metabolism , SARS Virus/metabolism , ADAM10 Protein/genetics , ADAM17 Protein/genetics , Amyloid Precursor Protein Secretases/genetics , Angiotensin-Converting Enzyme 2/genetics , Clustered Regularly Interspaced Short Palindromic Repeats , Extracellular Vesicles/genetics , HEK293 Cells , Humans , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Glycoproteins/genetics , Membrane Proteins/genetics , SARS Virus/genetics , SARS-CoV-2
2.
Cells ; 11(4)2022 02 11.
Article in English | MEDLINE | ID: covidwho-1688673

ABSTRACT

Transmembrane proteins of adherens and tight junctions are known targets for viruses and bacterial toxins. The coronavirus receptor ACE2 has been localized at the apical surface of epithelial cells, but it is not clear whether ACE2 is localized at apical Cell-Cell junctions and whether it associates with junctional proteins. Here we explored the expression and localization of ACE2 and its association with transmembrane and tight junction proteins in epithelial tissues and cultured cells by data mining, immunoblotting, immunofluorescence microscopy, and co-immunoprecipitation experiments. ACE2 mRNA is abundant in epithelial tissues, where its expression correlates with the expression of the tight junction proteins cingulin and occludin. In cultured epithelial cells ACE2 mRNA is upregulated upon differentiation and ACE2 protein is widely expressed and co-immunoprecipitates with the transmembrane proteins ADAM17 and CD9. We show by immunofluorescence microscopy that ACE2 colocalizes with ADAM17 and CD9 and the tight junction protein cingulin at apical junctions of intestinal (Caco-2), mammary (Eph4) and kidney (mCCD) epithelial cells. These observations identify ACE2, ADAM17 and CD9 as new epithelial junctional transmembrane proteins and suggest that the cytokine-enhanced endocytic internalization of junction-associated protein complexes comprising ACE2 may promote coronavirus entry.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Intercellular Junctions/metabolism , Intercellular Junctions/virology , ADAM17 Protein/metabolism , Adherens Junctions/metabolism , Angiotensin-Converting Enzyme 2/genetics , Cadherins/metabolism , Carrier Proteins/metabolism , Cell Line , Cell Membrane Permeability , Coronavirus/metabolism , Epithelial Cells/metabolism , Epithelial Cells/virology , Gene Expression/genetics , Tetraspanin 29/metabolism , Tight Junction Proteins/metabolism , Tight Junctions/metabolism , Transcriptome/genetics
3.
Biochem Biophys Res Commun ; 593: 52-56, 2022 02 19.
Article in English | MEDLINE | ID: covidwho-1633160

ABSTRACT

COVID-19, the respiratory infection caused by the novel coronavirus SARS-CoV-2, presents a clinical picture consistent with the dysregulation of many of the pathways mediated by the metalloprotease ADAM17. ADAM17 is a sheddase that plays a key role in the modulation of ACE2, the receptor which also functions as the point of attachment leading to cell entry by the virus. This work investigates the possibility that ADAM17 dysregulation and attachment of the SARS-CoV-2 virion to the ACE2 receptor are linked events, with the latter causing the former. Tetraspanins, the transmembrane proteins that function as scaffolds for the construction of viral entry platforms, are mooted as key components in this connection.


Subject(s)
ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Receptors, Virus/metabolism , SARS-CoV-2/metabolism , Tetraspanin 29/metabolism , Virus Internalization , ADAM17 Protein/chemistry , Angiotensin-Converting Enzyme 2/chemistry , Binding Sites , COVID-19/epidemiology , COVID-19/transmission , COVID-19/virology , Humans , Models, Biological , Molecular Docking Simulation , Multiprotein Complexes/chemistry , Multiprotein Complexes/metabolism , Pandemics , Protein Binding , Protein Domains , Receptors, Virus/chemistry , SARS-CoV-2/physiology , Tetraspanin 29/chemistry
4.
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
5.
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
6.
Biochem Biophys Res Commun ; 573: 158-163, 2021 10 08.
Article in English | MEDLINE | ID: covidwho-1446454

ABSTRACT

The angiotensin Converting Enzyme 2 (ACE2) receptor is a key component of the renin-angiotensin-aldesterone system (RAAS) that mediates numerous effects in the cardiovascular system. It is also the cellular point of contact for the coronavirus spike protein. Cleavage of the receptor is both important to its physiological function as well as being necessary for cell entry by the virus. Shedding of ACE2 by the metalloprotease ADAM17 releases a catalytically active soluble form of ACE2, but cleavage by the serine protease TMPRSS2 is necessary for virion internalization. Complicating the issue is the observation that circulating ACE2 can also bind to the virus effectively blocking attachment to the membrane-bound receptor. This work investigates the possibility that the inflammatory response to coronavirus infection can abrogate shedding by ADAM17, thereby favoring cleavage by TMPRSS2 and thus cell entry by the virion.


Subject(s)
ADAM17 Protein/chemistry , ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , HSP20 Heat-Shock Proteins/metabolism , Host-Pathogen Interactions/physiology , SARS-CoV-2/pathogenicity , Angiotensin-Converting Enzyme 2/chemistry , Binding Sites , HSP20 Heat-Shock Proteins/chemistry , Heat-Shock Response/physiology , Humans , Protein Domains , Protein Interaction Domains and Motifs , Serine Endopeptidases/metabolism , Virus Internalization
7.
Int J Mol Med ; 48(4)2021 Oct.
Article in English | MEDLINE | ID: covidwho-1367949

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) is the virus that causes coronavirus disease 2019. Angiotensin­converting enzyme 2 (ACE2) is the SARS­CoV binding site and is ubiquitously expressed in endothelial cells of several organs, with the highest levels in the cardiovascular system, kidney and lungs. A disintegrin and metalloproteinase 17 (ADAM17) is involved in ectodomain shedding of ACE2. In the present study, reverse­transcription­quantitative PCR, transfection, TUNNEL assay, dual­luciferase activity assay and western blotting were conducted to investigate the effects of microRNA (miR)­28­3p on ADAM17­dependent shedding of the ACE2 ectodomain following treatment with the spike protein (S­protein) of SARS­CoV­2. It was found that miR­28­3p was significantly downregulated in 293T cells treated with 100 ng/ml of S­protein for 24 h at 37˚C, which led to upregulation of ADAM17. In addition, the expression of ADAM17 and miR­28­3p were negatively correlated based on Pearson's correlation test in 293T cells treated with S­protein for 24 h. Overexpression of miR­28­3p and inhibition of ADAM17 regulated 293T cell viability, apoptosis and ACE2 ectodomain shedding. It was also demonstrated that ADAM17 was the target gene of miR­28­3p and that miR­28­3p negatively regulated ADAM17 expression. Notably, the inhibition of ADAM17 expression blocked the effects of miR­28­3p inhibitor on proliferation, apoptosis and ACE2 ectodomain shedding in 293T cells treated with S­protein. The findings of the present study suggested that miR­28­3p inhibits ADAM17­dependent ACE2 ectodomain shedding in 293T cells treated with the S­protein of SARS­CoV­2, which suggested the potential therapeutic role of miR­28­3p mimic in the prevention and treatment of patients with SARS­CoV­2.


Subject(s)
ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/chemistry , COVID-19/immunology , Gene Expression Profiling , MicroRNAs/physiology , Apoptosis , COVID-19/virology , Cell Proliferation , Cell Survival , Gene Expression Regulation, Viral , HEK293 Cells , Humans , MicroRNAs/antagonists & inhibitors , Protein Domains
8.
Am J Ther ; 28(3): e358-e360, 2020 Aug 03.
Article in English | MEDLINE | ID: covidwho-1349825

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a rapidly expanding global health crisis. A disintegrin and metalloproteinase 17 (ADAM17), an ectodomain sheddase, is a key component of ACE2 modulation and plays a complex role in inflammation and immunosurveillance. AREAS OF UNCERTAINTY: Much remains unknown regarding the immunopathogenesis of COVID-19, including how the virus affects ADAM17 expression, activity, and regulation. SEARCH STRATEGY: Three electronic databases (MEDLINE through PubMed, Embase through Ovid, and Google Scholar) were searched to identify articles relevant to ADAM17 and severe acute respiratory syndrome coronavirus 1 and 2. Relevant articles published from January 1, 2005, to April 30, 2020, were selected, and reference lists were screened and cross-referenced. We also searched preprint studies on medRxiv and bioRxiv given the rapidly evolving data on COVID-19 SARS-CoV-2. THERAPEUTIC OPINION: Infection with SARS-CoV-2 may lead to an increase in ADAM17 sheddase activity contributing to an exuberant macrophage-predominant inflammatory response and diminished immunosurveillance capacity for viral clearance. Emerging data suggest severe lung injury in COVID-19 is associated with higher levels of TNF-α and IL-6, T-cell lymphopenia and exhaustion, hypercoagulability, and a macrophage-predominant immune response. This clinical picture is consistent with dysregulation of many of the molecular pathways in which ADAM17 participates. CONCLUSIONS: Elucidation of the role of ADAM17 in COVID-19 may identify novel molecular targets for drug development and therapeutic repurposement.


Subject(s)
ADAM17 Protein , COVID-19 , SARS-CoV-2/physiology , Signal Transduction/immunology , ADAM17 Protein/immunology , ADAM17 Protein/metabolism , COVID-19/immunology , COVID-19/virology , Drug Discovery , Gene Expression , Humans , Immunity
9.
Biol Futur ; 72(3): 291-297, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1261840

ABSTRACT

COVID-19 is a disease-causing current pandemic. It prevails in patients with pre-existing conditions such as diabetes and hypertension. Renin-angiotensin system was identified as a center of COVID-19 pathophysiology. There is a current controversy concerning the usage of ACE inhibitors and AR blockers in patients with COVID-19. Multiple clinical trials are on the way to determine the effect of RAS blockers in patients with COVID-19. ACE2 receptor is thought to be the point of entry utilized by a coronavirus. However, other factors have been identified which potentially facilitate SARS-CoV-2 entry into the cell. ADAM17 could facilitate viral entry in hyperglycemic and diabetic patients. Insulin is an ADAM17 inhibitor. Heme oxygenase (HO)-1 level is reduced in diabetic patients, contributing to the worst outcome for patients with poor glycemic control. The combined therapy of glycemic control and antioxidant response to oxidative stress could be explored in patients with COVID-19.


Subject(s)
ADAM17 Protein/metabolism , COVID-19/complications , Diabetes Mellitus/metabolism , Hyperglycemia , SARS-CoV-2 , ADAM17 Protein/genetics , Humans , Virus Internalization
10.
Front Immunol ; 12: 641295, 2021.
Article in English | MEDLINE | ID: covidwho-1241168

ABSTRACT

Although millions of patients with underlining conditions are treated primarily with anti-TNF-α agents, little is known about the safety of this standard therapy during the coronavirus disease-2019 (COVID-19) pandemic. In this study, we investigated the effect of anti-TNF-α monoclonal antibodies on the cellular entry mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increasing the risk of COVID-19 development. We focused on the expression of angiotensin-converting enzyme II (ACE2), type II transmembrane serine proteases (TMPRSS2)/TNF-α converting enzyme (TACE) ratio. We also investigated the involvement of Notch-1 signaling and its downstream influence on IL-6, myeloid cell leukemia sequence-1(MCL-1) in the anti-TNF-α mode of action and increased the susceptibility to Mycobacterium avium subspecies paratuberculosis (MAP) infection. Surprisingly, anti-TNF-α downregulated ACE2 expression by 0.46-fold and increased TMPRSS2/TACE ratio by 44% in THP-1 macrophages. Treatment of macrophages with rIL-6 also downregulated ACE2 and increased TMPRSS2/TACE ratio by 54%. Interestingly, anti-TNF-α treatment upregulated Notch-1, IL-6, and MCL-1 by 1.3, 1.2, and 1.9-fold, respectively, and increased viability and burden of MAP infection in macrophages. Blocking Notch signaling doubled ACE2 expression, decreased TMPRSS2/TACE ratio by 38%, and reduced MAP viability by 56%. In a small group of patients, ACE2 level was significantly lower in the plasma from rheumatoid arthritis (RA) patients on anti-TNF-α treatment compared to healthy control. The data in this critical study demonstrated that through Notch-1/IL-6 signaling, anti-TNF-α agents decreased ACE2 expression and shedding through TMPRSS2/TACE modulation and increased the susceptibility to infection. Overall, this study warns against anti-TNF-α therapy in some patients with underlining inflammatory conditions during the COVID-19 pandemic. The findings should impact current guidelines regarding treatment decisions of patients on anti-TNF-α during the COVID-19 pandemic.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/immunology , Macrophages/immunology , Mycobacterium avium/physiology , Receptor, Notch1/metabolism , SARS-CoV-2/physiology , Tuberculosis, Avian/immunology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , ADAM17 Protein/metabolism , Animals , COVID-19/transmission , COVID-19/virology , Disease Susceptibility , Disease Transmission, Infectious , Humans , Interleukin-6/metabolism , Risk , Serine Endopeptidases/metabolism , Signal Transduction , THP-1 Cells
11.
Int J Mol Sci ; 22(9)2021 Apr 26.
Article in English | MEDLINE | ID: covidwho-1201474

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) is the entry receptor for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of Coronavirus Disease-2019 (COVID-19) in humans. ACE-2 is a type I transmembrane metallocarboxypeptidase expressed in vascular endothelial cells, alveolar type 2 lung epithelial cells, renal tubular epithelium, Leydig cells in testes and gastrointestinal tract. ACE2 mediates the interaction between host cells and SARS-CoV-2 spike (S) protein. However, ACE2 is not only a SARS-CoV-2 receptor, but it has also an important homeostatic function regulating renin-angiotensin system (RAS), which is pivotal for both the cardiovascular and immune systems. Therefore, ACE2 is the key link between SARS-CoV-2 infection, cardiovascular diseases (CVDs) and immune response. Susceptibility to SARS-CoV-2 seems to be tightly associated with ACE2 availability, which in turn is determined by genetics, age, gender and comorbidities. Severe COVID-19 is due to an uncontrolled and excessive immune response, which leads to acute respiratory distress syndrome (ARDS) and multi-organ failure. In spite of a lower ACE2 expression on cells surface, patients with CVDs have a higher COVID-19 mortality rate, which is likely driven by the imbalance between ADAM metallopeptidase domain 17 (ADAM17) protein (which is required for cleavage of ACE-2 ectodomain resulting in increased ACE2 shedding), and TMPRSS2 (which is required for spike glycoprotein priming). To date, ACE inhibitors and Angiotensin II Receptor Blockers (ARBs) treatment interruption in patients with chronic comorbidities appears unjustified. The rollout of COVID-19 vaccines provides opportunities to study the effects of different COVID-19 vaccines on ACE2 in patients on treatment with ACEi/ARB.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , Cardiovascular Diseases/pathology , SARS-CoV-2/physiology , ADAM17 Protein/metabolism , COVID-19/complications , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/immunology , Cardiovascular Diseases/complications , Humans , Receptors, Virus/metabolism , SARS-CoV-2/isolation & purification , Serine Endopeptidases/metabolism
12.
Int J Mol Sci ; 22(1)2020 Dec 25.
Article in English | MEDLINE | ID: covidwho-1001758

ABSTRACT

Angiotensin converting enzyme 2 (ACE2) is a critical component of the compensatory axis of the renin angiotensin system. Alterations in ACE2 gene and protein expression, and activity mediated by A Disintegrin And Metalloprotease 17 (ADAM17), a member of the "A Disintegrin And Metalloprotease" (ADAM) family are implicated in several cardiovascular and neurodegenerative diseases. We previously reported that activation of kinin B1 receptor (B1R) in the brain increases neuroinflammation, oxidative stress and sympathoexcitation, leading to the development of neurogenic hypertension. We also showed evidence for ADAM17-mediated ACE2 shedding in neurons. However, whether kinin B1 receptor (B1R) activation has any role in altering ADAM17 activity and its effect on ACE2 shedding in neurons is not known. In this study, we tested the hypothesis that activation of B1R upregulates ADAM17 and results in ACE2 shedding in neurons. To test this hypothesis, we stimulated wild-type and B1R gene-deleted mouse neonatal primary hypothalamic neuronal cultures with a B1R-specific agonist and measured the activities of ADAM17 and ACE2 in neurons. B1R stimulation significantly increased ADAM17 activity and decreased ACE2 activity in wild-type neurons, while pretreatment with a B1R-specific antagonist, R715, reversed these changes. Stimulation with specific B1R agonist Lys-Des-Arg9-Bradykinin (LDABK) did not show any effect on ADAM17 or ACE2 activities in neurons with B1R gene deletion. These data suggest that B1R activation results in ADAM17-mediated ACE2 shedding in primary hypothalamic neurons. In addition, stimulation with high concentration of glutamate significantly increased B1R gene and protein expression, along with increased ADAM17 and decreased ACE2 activities in wild-type neurons. Pretreatment with B1R-specific antagonist R715 reversed these glutamate-induced effects suggesting that indeed B1R is involved in glutamate-mediated upregulation of ADAM17 activity and ACE2 shedding.


Subject(s)
ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Neurons/metabolism , Animals , Cells, Cultured , Gene Expression Regulation/drug effects , Glutamic Acid/metabolism , Glutamic Acid/pharmacology , Hypothalamus/metabolism , Mice , Mice, Knockout , Models, Biological , Pyramidal Cells/metabolism
13.
Cells ; 10(3)2021 02 27.
Article in English | MEDLINE | ID: covidwho-1122409

ABSTRACT

The article describes the rationale for the administration of zinc-chelating agents in COVID-19 patients. In a previous work I have highlighted that the binding of the SARS-CoV spike proteins to the zinc-metalloprotease ACE2 has been shown to induce ACE2 shedding by activating the zinc-metalloprotease ADAM17, which ultimately leads to systemic upregulation of ACE2 activity. Moreover, based on experimental models, it was also shown the detrimental effect of the excessive systemic activity of ACE2 through its downstream pathways, which leads to "clinical" manifestations resembling COVID-19. In this regard, strong upregulation of circulating ACE2 activity was recently reported in COVID-19 patients, thus supporting the previous hypothesis that COVID-19 may derive from upregulation of ACE2 activity. Based on this, a reasonable hypothesis of using inhibitors that curb the upregulation of both ACE2 and ADAM17 zinc-metalloprotease activities and consequent positive feedback-loops (initially triggered by SARS-CoV-2 and subsequently sustained independently on viral trigger) is proposed as therapy for COVID-19. In particular, zinc-chelating agents such as citrate and ethylenediaminetetraacetic acid (EDTA) alone or in combination are expected to act in protecting from COVID-19 at different levels thanks to their both anticoagulant properties and inhibitory activity on zinc-metalloproteases. Several arguments are presented in support of this hypothesis and based on the current knowledge of both beneficial/harmful effects and cost/effectiveness, the use of chelating agents in the prevention and therapy of COVID-19 is proposed. In this regard, clinical trials (currently absent) employing citrate/EDTA in COVID-19 are urgently needed in order to shed more light on the efficacy of zinc chelators against SARS-CoV-2 infection in vivo.


Subject(s)
COVID-19/drug therapy , Chelating Agents/pharmacology , Citric Acid/pharmacology , Edetic Acid/pharmacology , Renin-Angiotensin System/drug effects , Zinc/metabolism , ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Anticoagulants/pharmacology , COVID-19/metabolism , COVID-19/therapy , Drug Discovery , Humans , Immunization, Passive/adverse effects , SARS-CoV-2/drug effects , Up-Regulation/drug effects
14.
J Cell Mol Med ; 25(8): 3840-3855, 2021 04.
Article in English | MEDLINE | ID: covidwho-1116957

ABSTRACT

Congestive heart failure (CHF) is often associated with kidney and pulmonary dysfunction. Activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid sodium retention, cardiac hypertrophy and oedema formation, including lung congestion. While the status of the classic components of RAAS such as renin, angiotensin converting enzyme (ACE), angiotensin II (Ang II) and angiotensin II receptor AT-1 is well studied in CHF, the expression of angiotensin converting enzyme-2 (ACE2), a key enzyme of angiotensin 1-7 (Ang 1-7) generation in the pulmonary, cardiac and renal systems has not been studied thoroughly in this clinical setting. This issue is of a special interest as Ang 1-7 counterbalance the vasoconstrictory, pro-inflammatory and pro-proliferative actions of Ang II. Furthermore, CHF predisposes to COVID-19 disease severity, while ACE2 also serves as the binding domain of SARS-CoV-2 in human host-cells, and acts in concert with furin, an important enzyme in the synthesis of BNP in CHF, in permeating viral functionality along TMPRSST2. ADAM17 governs ACE2 shedding from cell membranes. Therefore, the present study was designed to investigate the expression of ACE2, furin, TMPRSS2 and ADAM17 in the lung, heart and kidneys of rats with CHF to understand the exaggerated susceptibility of clinical CHF to COVID-19 disease. Heart failure was induced in male Sprague Dawley rats by the creation of a surgical aorto-caval fistula. Sham-operated rats served as controls. One week after surgery, the animals were subdivided into compensated and decompensated CHF according to urinary sodium excretion. Both groups and their controls were sacrificed, and their hearts, lungs and kidneys were harvested for assessment of tissue remodelling and ACE2, furin, TMPRSS2 and ADAM17 immunoreactivity, expression and immunohistochemical staining. ACE2 immunoreactivity and mRNA levels increased in pulmonary, cardiac and renal tissues of compensated, but not in decompensated CHF. Furin immunoreactivity was increased in both compensated and decompensated CHF in the pulmonary, cardiac tissues and renal cortex but not in the medulla. Interestingly, both the expression and abundance of pulmonary, cardiac and renal TMPRSS2 decreased in CHF in correlation with the severity of the disease. Pulmonary, cardiac and renal ADAM17 mRNA levels were also downregulated in decompensated CHF. Circulating furin levels increased in proportion to CHF severity, whereas plasma ACE2 remained unchanged. In summary, ACE2 and furin are overexpressed in the pulmonary, cardiac and renal tissues of compensated and to a lesser extent of decompensated CHF as compared with their sham controls. The increased expression of the ACE2 in heart failure may serve as a compensatory mechanism, counterbalancing the over-activity of the deleterious isoform, ACE. Downregulated ADAM17 might enhance membranal ACE2 in COVID-19 disease, whereas the suppression of TMPRSS2 in CHF argues against its involvement in the exaggerated susceptibility of CHF patients to SARS-CoV2.


Subject(s)
ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Furin/metabolism , Heart Failure/metabolism , Serine Endopeptidases/metabolism , ADAM17 Protein/genetics , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , Disease Models, Animal , Gene Expression , Heart Failure/genetics , Humans , Kidney/metabolism , Lung/metabolism , Male , Myocardium/metabolism , Rats, Sprague-Dawley , Renin-Angiotensin System/physiology , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Serine Endopeptidases/genetics
15.
Viruses ; 13(1)2020 12 26.
Article in English | MEDLINE | ID: covidwho-1079698

ABSTRACT

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) poses a persistent threat to global public health. Although primarily a respiratory illness, extrapulmonary manifestations of COVID-19 include gastrointestinal, cardiovascular, renal and neurological diseases. Recent studies suggest that dysfunction of the endothelium during COVID-19 may exacerbate these deleterious events by inciting inflammatory and microvascular thrombotic processes. Although controversial, there is evidence that SARS-CoV-2 may infect endothelial cells by binding to the angiotensin-converting enzyme 2 (ACE2) cellular receptor using the viral Spike protein. In this review, we explore current insights into the relationship between SARS-CoV-2 infection, endothelial dysfunction due to ACE2 downregulation, and deleterious pulmonary and extra-pulmonary immunothrombotic complications in severe COVID-19. We also discuss preclinical and clinical development of therapeutic agents targeting SARS-CoV-2-mediated endothelial dysfunction. Finally, we present evidence of SARS-CoV-2 replication in primary human lung and cardiac microvascular endothelial cells. Accordingly, in striving to understand the parameters that lead to severe disease in COVID-19 patients, it is important to consider how direct infection of endothelial cells by SARS-CoV-2 may contribute to this process.


Subject(s)
COVID-19/metabolism , Endothelial Cells/metabolism , Endothelium/metabolism , SARS-CoV-2/immunology , ADAM17 Protein/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/therapeutic use , COVID-19/immunology , Coronavirus , Coronavirus Infections/metabolism , Endothelial Cells/immunology , Endothelium/immunology , Endothelium/virology , Endothelium, Vascular/immunology , Endothelium, Vascular/metabolism , Humans , Lung/metabolism , Thrombosis , Virus Replication
16.
FASEB J ; 35(3): e21419, 2021 03.
Article in English | MEDLINE | ID: covidwho-1075599

ABSTRACT

In the early phase of the Coronavirus disease 2019 (COVID-19) pandemic, it was postulated that the renin-angiotensin-system inhibitors (RASi) increase the infection risk. This was primarily based on numerous reports, which stated that the RASi could increase the organ Angiotensin-converting enzyme 2 (ACE2), the receptor of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in rodents. RASi can theoretically antagonize the potential influence of angiotensin II (Ang II) on ACE2. However, while Ang II decreases the ACE2 levels in cultured cells, there is little evidence that supports this phenomenon in living animals. In this study, we tested whether Ang II or Ang II combined with its antagonist would alter the ACE2 and other molecules associated with the infection of SARS-CoV-2. Male C57BL6/J mice were administered vehicle, Ang II (400 ng/kg/min), or Ang II with losartan (10 mg/kg/min) for 2 weeks. ACE2 knockout mice were used as a negative control for the ACE2 assay. We found that both Ang II, which elevated blood pressure by 30 mm Hg, and Ang II with losartan, had no effect on the expression or protein activity of ACE2 in the lung, left ventricle, kidney, and ileum. Likewise, these interventions had no effect on the expression of Transmembrane Protease Serine 2 (TMPRSS2) and Furin, proteases that facilitate the virus-cell fusion, and the expression or activity of Tumor Necrosis Factor α-Convertase (TACE) that cleaves cell-surface ACE2. Collectively, physiological concentrations of Ang II do not modulate the molecules associated with SARS-CoV-2 infection. These results support the recent observational studies suggesting that the use of RASi is not a risk factor for COVID-19.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/pharmacology , Angiotensin II/pharmacology , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Losartan/pharmacology , SARS-CoV-2 , ADAM17 Protein/genetics , ADAM17 Protein/metabolism , Angiotensin II/administration & dosage , Angiotensin II Type 1 Receptor Blockers/administration & dosage , Angiotensin-Converting Enzyme 2/genetics , Animals , Furin/genetics , Furin/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Losartan/administration & dosage , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Vasoconstrictor Agents/pharmacology
17.
Iran J Allergy Asthma Immunol ; 19(5): 456-470, 2020 Oct 18.
Article in English | MEDLINE | ID: covidwho-1068112

ABSTRACT

The new coronavirus, known as "SARS-CoV-2"; is the cause of one of the most prevalent infectious viral diseases that was recently announced pandemic by the world health organization. Ongoing research in the fields of prevention, management, and therapy establishes a functional scaffold for clinics during the time of crisis. To obtain this goal, it is necessary that all pathophysiologic aspects of COVID-19 from infection to predisposing backgrounds of infection be identified, so that all the ambiguities of researchers regarding transmission mechanisms, variable clinical manifestation, and therapeutic response can be solved. Here, we firstly discuss about the homology screening between nCoV-2019 and beta-coronavirus family using phylogenetic analyses. Secondly, we analyzed the viral motifs to show that viral entry into the host cells requires a primary activation step performed by FURIN and FURIN-like-mediated enzymatic cleavage on the structural glycoprotein. The cleavage increases viral performance by 1000 folds. We then present a comprehensive view on host cells and the significance of gene variants affecting activation enzymes, supportive entry, and spread mechanisms in humans including renin-angiotensin-aldosterone system (RAAS) a pathway results in certain phenotypes or exacerbate infection-related phenotypes in different organs, hence causes variable clinical manifestations. This is followed by discussing about the importance of personalized medicine in nCoV-2019 exposure. Moreover, chemical drugs prescribed for individuals affected with COVID-19, as well as genes involved in drug transport and metabolisms are reviewed as a prelude to drug response. Finally, we suggest some therapeutic approaches developed based on new methods and technology such as anti-sense therapy and antibodies.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/genetics , Furin/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , ADAM17 Protein/genetics , ADAM17 Protein/metabolism , Angiotensin II Type 1 Receptor Blockers/therapeutic use , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Anti-Bacterial Agents/therapeutic use , Azithromycin/therapeutic use , Betacoronavirus/genetics , COVID-19/drug therapy , COVID-19/physiopathology , COVID-19/transmission , Enzyme Inhibitors/therapeutic use , Furin/metabolism , Genetic Predisposition to Disease , Genome, Human , Genome, Viral , Humans , Hydroxychloroquine/therapeutic use , Phylogeny , Precision Medicine , Receptors, Coronavirus/genetics , Receptors, Coronavirus/metabolism , Renin-Angiotensin System/genetics , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
19.
Clin Sci (Lond) ; 135(3): 465-481, 2021 02 12.
Article in English | MEDLINE | ID: covidwho-1043627

ABSTRACT

The key link between renin-angiotensin system (RAS) and COVID-19 is ACE2 (angiotensin-converting enzyme 2), which acts as a double-edged sword, because ACE2 increases the tissue anti-inflammatory response but it is also the entry receptor for the virus. There is an important controversy on several drugs that regulate RAS activity and possibly ACE2, and are widely used, particularly by patients most vulnerable to severe COVID-19. In the lung of healthy rats, we observed that candesartan (an angiotensin type-1, AT1, receptor blocker; ARB) and captopril (an ACE inhibitor; ACEI) up-regulated expression of tissue ACE2 and RAS anti-inflammatory axis receptors (AT2 and Mas receptors). This effect was particularly pronounced in rats with metabolic syndrome (obesity, increased blood pressure and hyperglycemia) and aged rats. Treatment of cultures of human type-II pneumocytes with candesartan or captopril induced up-regulation of ACE2 expression in cells. Treatment with viral spike protein induced a decrease in full-length (i.e. transmembrane) ACE2, an increase in levels of a short intracellular ACE2 polypeptide and an increase in ADAM17 activity in cells, together with an increase in levels of soluble ACE2 and major proinflammatory cytokines in the culture medium. Spike protein-induced changes and levels of spike protein internalization in cells were inhibited by pretreatment with the above-mentioned drugs. The results suggest that these drugs increase ACE2 levels and promote the anti-inflammatory RAS axis in the lung. Furthermore, possible up-regulation of viral entry by the drug-induced increase in expression of transmembrane ACE2 is counteracted by additional mechanisms, particularly by drug-induced inhibition of ADAM17 activity.


Subject(s)
Benzimidazoles/administration & dosage , Biphenyl Compounds/administration & dosage , COVID-19/drug therapy , Captopril/administration & dosage , Tetrazoles/administration & dosage , ADAM17 Protein/genetics , ADAM17 Protein/metabolism , Angiotensin II Type 1 Receptor Blockers/administration & dosage , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Animals , COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , Female , Humans , Lung/metabolism , Lung/virology , Male , Rats , Renin-Angiotensin System/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/physiology
20.
J Biol Chem ; 295(35): 12353-12354, 2020 08 28.
Article in English | MEDLINE | ID: covidwho-990137

ABSTRACT

Sheddases are specialized proteases that control the abundance and function of membrane proteins by cleaving their substrate's extracellular domain (ectodomain), a process known as shedding. Hundreds of shedding substrates have been identified, but little is known about the mechanisms that govern ectodomain shedding. Iwagishi et al. now report that negatively charged amino acids in the membrane-proximal juxtamembrane domain of substrates make them resistant to shedding by the metalloprotease ADAM17. These findings will help researchers better understand the regulation of shedding and may aid in the development of drugs targeting sheddases.


Subject(s)
ADAM Proteins , Membrane Proteins , ADAM Proteins/metabolism , ADAM17 Protein/metabolism , Amino Acids/metabolism , Cell Membrane/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Proteolysis
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