Angiotensin-converting enzyme 2 (ACE2) in COVID-19 and other diseases.

The coronavirus SARS-CoV-2 was detected in isolates of pneumonia patients in January 2020. The virus cannot multiply extracellularly but requires access to the cells of a host organism. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as a receptor, to which it docks with its spikes. ACE2 belongs to the renin angiotensin system (RAS), whose inhibitors have been used for years against high blood pressure. Renin is an endopeptidase that is predominantly formed in the juxtaglomerular apparatus of the kidney and cleaves the decapeptide angiotensin I (Ang I) from angiotensinogen. Through the angiotensin-converting enzyme (ACE), another 2 C-terminal amino acids are removed from Ang I, so that finally the active octapeptide angiotensin II (Ang II) is formed. The biological effect of Ang II via the angiotensin II receptor subtype 1 (AT1-R) consists of vasoconstriction, fibrosis, proliferation, inflammation, and thrombosis formation. ACE2 is a peptidase that is a homolog of ACE. ACE2 is predominantly expressed by pulmonary alveolar epithelial cells in humans and has been detected in arterial and venous endothelial cells. In contrast to the dicarboxy-peptidase ACE, ACE2 is a monocarboxypeptidase that cleaves only one amino acid from the C-terminal end of the peptides. ACE2 can hydrolyze the nonapeptide Ang-(1-9) from the decapeptide Ang I and the heptapeptide Ang-(1-7) from the octapeptide Ang II. Ang-(1-7) acts predominantly antagonistically (vasodilatory, anti-fibrotic, anti-proliferative, anti-inflammatory, anti-thrombogenetically) via the G protein-coupled Mas receptor to the AT1-R-mediated effects of Ang II. In the pathogenesis of COVID-19 infection, it is therefore assumed that there is an imbalance due to overstimulation of the AT1 receptor in conjunction with a weakening of the biological effects of the Mas receptor.Copyright © 2022 Dustri-Verlag Dr. K. Feistle.

Alzheimer's disease and COVID-19.

In elderly patients with COVID-19 cognitive functions decline;it has been suggested that SARS-CoV-2 infection may lead to the development of Alzheimer's disease (AD) and other long-term neurological consequences. We review several parallels between AD and COVID-19 in terms of pathogenetic mechanisms and risk factors. Possible mechanisms through which COVID-19 can initiate AD are discussed. These include systemic inflammation, hyperactivation of the renin-angiotensin system, innate immune activation, oxidative stress, and direct viral damage. It has been shown that increased expression of angiotensin-renin receptors (ACE2) may be a risk factor for COVID-19 in patients with AD. When entering the central nervous system, the SARS-CoV-2 virus can directly activate glial cell-mediated immune responses, which in turn can lead to the accumulation of beta-amyloid and the subsequent onset or progression of current AD. The involvement of inflammatory biomarkers, including interleukins (IL): IL6, IL1, as well as galectin-3, as a link between COVID-19 and AD is discussed. The rationale for the use of memantine (akatinol memantine) in patients with COVID-19 in order to prevent the development of cognitive deficits is discussed. Memantine has been shown to have a positive effect on neuroinflammatory processes in the onset or exacerbation of cognitive deficits, in reducing cerebral vasospasm and endothelial dysfunction in viral infections. Memantine therapy may improve everyday activity and reduce the risk of severe SARS-CoV-2 infection.Copyright © 2022 Ima-Press Publishing House. All rights reserved.

ASSOCIATIONS OF POLYMORPHISMS OF THE ACE AND ACE2 GENES WITH CLINICAL MANIFESTATIONS AND CARDIOVASCULAR COMPLICATIONS OF THE CORONAVIRUS INFECTION

A problem of the novel coronavirus infection pandemic is the absence of specific biomarkers, the determination of which would make it possible to assess the likelihood of a severe disease course, development of complications, immediate and long-term consequences, and effective etiotropic (antiviral) therapy. The severity of the novel coronavirus infection depends on various factors such as the initial state of health, immune status, age, smoking status, concomitant cardiovascular diseases, and diabetes mellitus. However, a severe disease course is also observed in patients without the aforementioned risk factors. The development of the disease and its complications depends on sex and geographical identity. Angiotensin-converting enzyme 2 (ACE2), associated by gene-gene interaction with ACE, plays a main role in the pathogenesis of the penetration of severe acute respiratory syndrome-2 coronavirus into the cell. The main body of information on this problem is represented by systematic meta-analyses and results of single-center cohort studies, which offer insufficient information to unequivocally assert the associations of ACE and ACE2 gene polymorphisms with pathological changes in the circulatory system during and after a new coronavirus infection. Differences in the incidence of ACE and ACE2 alleles may explain the differences between susceptible populations and/or response to the severe coronavirus infection. The above studies were carried out on the effect of the coronavirus in the initial period of the pandemic. For a more complete molecular genetic picture of the influence of polymorphism, persons with different strains of the coronavirus must be considered. In addition, no data are available regarding the expressions of ACE and ACE2 genes in response to a coronavirus infection. Moreover, the identification of the polymorphic variants of the genes of the renin–angiotensin–aldosterone system and ACE2 associated with a high risk of developing and worsening cardiovascular diseases may be one of the promising areas for the early diagnosis and prevention of post-COVID-19 changes. Therefore, all scientific interest research is aimed at studying genetic factors, such as single nucleotide polymorphisms that affect susceptibility to infection, severity of the disease course, and development of circulatory system consequences. In general, polymorphic variants of ACE and ACE2 and their interaction will help us understand this problem and systematize knowledge for further research in this area. All rights reserved © Eco-Vector, 2022.

Alzheimer's disease and COVID-19

In elderly patients with COVID-19 cognitive functions decline;it has been suggested that SARS-CoV-2 infection may lead to the development of Alzheimer's disease (AD) and other long-term neurological consequences. We review several parallels between AD and COVID-19 in terms of pathogenetic mechanisms and risk factors. Possible mechanisms through which COVID-19 can initiate AD are discussed. These include systemic inflammation, hyperactivation of the renin-angiotensin system, innate immune activation, oxidative stress, and direct viral damage. It has been shown that increased expression of angiotensin-renin receptors (ACE2) may be a risk factor for COVID-19 in patients with AD. When entering the central nervous system, the SARS-CoV-2 virus can directly activate glial cell-mediated immune responses, which in turn can lead to the accumulation of beta-amyloid and the subsequent onset or progression of current AD. The involvement of inflammatory biomarkers, including interleukins (IL): IL6, IL1, as well as galectin-3, as a link between COVID-19 and AD is discussed. The rationale for the use of memantine (akatinol memantine) in patients with COVID-19 in order to prevent the development of cognitive deficits is discussed. Memantine has been shown to have a positive effect on neuroinflammatory processes in the onset or exacerbation of cognitive deficits, in reducing cerebral vasospasm and endothelial dysfunction in viral infections. Memantine therapy may improve everyday activity and reduce the risk of severe SARS-CoV-2 infection.Copyright © 2022 Ima-Press Publishing House. All rights reserved.

ACE and ACE2 catalytic activity in the fecal content along the gut.

BACKGROUND: Angiotensin-converting enzyme (ACE) and ACE2 are two major enzymes of the renin-angiotensin-aldosterone system (RAAS), which control the formation/degradation of angiotensin (Ang) II and Ang1-7, regulating their opposite effects. We aimed at evaluating the catalytic activity of ACE and ACE2 in the intestinal content and corresponding intestinal tissue along the gut of Wistar Han rats. METHODS: Portions of the ileum, cecum, proximal colon, and distal colon, and the corresponding intestinal content were collected from Wistar Han rats. Enzyme activity was evaluated by fluorometric assays using different substrates: Hippuryl-His-Leu for ACE-C-domain, Z-Phe-His-Leu for ACE-N-domain, and Mca-APK(Dnp) for ACE2. ACE and ACE2 concentration was assessed by ELISA. Ratios concerning concentrations and activities were calculated to evaluate the balance of the RAAS. Statistical analysis was performed using Friedman test followed by Dunn's multiple comparisons test or Wilcoxon matched-pairs test whenever needed. KEY RESULTS: ACE and ACE2 are catalytically active in the intestinal content along the rat gut. The ACE N-domain shows higher activity than the C-domain both in the intestinal content and in the intestinal tissue. ACE and ACE2 are globally more active in the intestinal content than in the corresponding intestinal tissue. There was a distal-to-proximal prevalence of ACE2 over ACE in the intestinal tissue. CONCLUSIONS & INFERENCES: This work is the first to report the presence of catalytically active ACE and ACE2 in the rat intestinal content, supporting future research on the regulatory role of the intestinal RAAS on gut function and a putative link to the microbiome.

Ras and Sars-Cov-2 Interaction: Short Review of the Latest Evidence

Coronavirus SARS-CoV-2 is responsible for the coronavirus disease (COVID-19) cause of the recent global pandemic, which is causing thousands of deaths worldwide and represents a health challenge with few precedents in human history. The angiotensin 2 conversion enzyme (ACE-2) has been identified as the receptor that facilitates access to SARSCoV-2 in cells;evidence shows that its concentration varies during the various stages of viral infection. Therapeutic agents modifying the renin-angiotensin system (RAS) may be able to modulate the concentration of ACE-2 and the various components of the system. In this article we examine the latest evidence on the association between the use of RAS modifying agents and coronavirus 2019 (COVID-19) disease caused by SARS-CoV-2. Our investigation and critical literature research does not suggest discontinuation of ACEIs/ARBs treatment in clinical practice as there is a lack of robust evidence. However, we recommend further well-structured epidemiological studies investigating this sensitive issue that may provide important new suggestions for implementing guidelines.Copyright © Vitiello A., Ferrara F., 2023.

Alzheimer's disease and COVID-19.

In elderly patients with COVID-19 cognitive functions decline;it has been suggested that SARS-CoV-2 infection may lead to the development of Alzheimer's disease (AD) and other long-term neurological consequences. We review several parallels between AD and COVID-19 in terms of pathogenetic mechanisms and risk factors. Possible mechanisms through which COVID-19 can initiate AD are discussed. These include systemic inflammation, hyperactivation of the renin-angiotensin system, innate immune activation, oxidative stress, and direct viral damage. It has been shown that increased expression of angiotensin-renin receptors (ACE2) may be a risk factor for COVID-19 in patients with AD. When entering the central nervous system, the SARS-CoV-2 virus can directly activate glial cell-mediated immune responses, which in turn can lead to the accumulation of beta-amyloid and the subsequent onset or progression of current AD. The involvement of inflammatory biomarkers, including interleukins (IL): IL6, IL1, as well as galectin-3, as a link between COVID-19 and AD is discussed. The rationale for the use of memantine (akatinol memantine) in patients with COVID-19 in order to prevent the development of cognitive deficits is discussed. Memantine has been shown to have a positive effect on neuroinflammatory processes in the onset or exacerbation of cognitive deficits, in reducing cerebral vasospasm and endothelial dysfunction in viral infections. Memantine therapy may improve everyday activity and reduce the risk of severe SARS-CoV-2 infection.Copyright © 2022 Ima-Press Publishing House. All rights reserved.

Cardiovascular risk among patients recovered from COVID-19 in the short and medium term: what does the current evidence conclude?.

Cardiovascular risk and diseases among patients recovered from COVID-19 is a recent field of study in the world medical literature and is also of vital importance because a large number of patients develop complications once the acute phase of the disease is over. The broad spectrum of myocardial injury in cardiovascular diseases can range from the asymptomatic elevation of cardiac troponin levels to the development of fulminant myocarditis and/or circulatory shock, which can leave significant sequelae. Despite the fact that there is no clear strategy to treat cardiac events that occur during COVID-19 infection and taking into account that treatment is mainly aimed at relieving patients' symptoms as they arise, the objective of this work was to find out and collect current evidence on this subject, so that readers can be offered a reference guide in Spanish that contributes to the development of their health profession. The methodology used was a literature search in databases including Medline, Scopus and ScienceDirect within a time window between 2019 and 2022. The main results revealed that the molecular and pathophysiological mechanisms involved in post-COVID-19 syndrome include the renin-angiotensin-aldosterone system since SARS-CoV-2 tropism is linked to angiotensin-converting enzyme 2. This causes an alteration of the neurohumoral response of the cardiovascular, renal and digestive systems, generating deficits in the signaling pathways and causing direct damage to the heart, lungs and other organs. Post-COVID-19 syndrome, in general, is defined as the occurrence or persistence of symptoms three or four weeks after the acute phase of the disease. This could then be considered as a time window of risk and strict follow-up to assess in a personalized way the risk among the different groups of patients, especially those with a past history of cardiovascular disease. The main results revealed disorders such as heart failure, arrhythmias, pericarditis and myocarditis, which require early detection and occur days or even weeks after the acute phase of COVID-19.Copyright © La revista. Publicado por la Universidad de San Martin de Porres, Peru.

Pain in Covid-19 and Features of Pathogenetic Molecular Mechanisms

Although it has been almost three years since the World Health Organization (WHO) declared a pandemic, COVID-19 is still an unsolved problem, thereby attracting great scientific interest. The disease has a heterogeneous clinical picture with multiple manifestations from different organs and systems. Currently, COVID-19 is perceived as a polysyndromic inflammatory disease involving not only the respiratory system, but also the musculoskeletal system, the cardiovascular system, the skin, the excretory and the nervous system, and is accompanied by a number of hematological, gastrohepatoenterological and endocrine disorders. Various pain phenomena also appear in the clinical presentation of the disease, often as a single manifestation or in combination with symptoms from different organs and systems. The pathogenesis of pain is complex and there is still no consensus on the exact driving mechanisms. Several different signaling pathways play an important role in the generation of pain impulses and perception. They are different for different types of pain. At this stage, the role of angiotensin-converting enzyme 2 (ACE), the renin-angiotensin system (RAC), angiotensin 2 receptors (AT2R), direct neuronal invasion of the virus, the involvement of pro-inflammatory cytokines, hypoxia, the involvement of macrophages, is discussed. as well as the role of overactivity of the immune system, causing the so-called "cytokine storm". Pain is the result of complex biochemical processes influenced to varying degrees by biological, physiological and social factors. Our knowledge at this stage remains scarce and is the subject of many studies on the key pathogenic mechanisms. Therefore, the purpose of this review is to describe the known mechanisms for the occurrence and persistence of pain in patients with COVID-19, as well as to classify the pain phenomena and present its most common localizations. The diagnosis and treatment of COVID-19 and associated pain should be carried out by a multidisciplinary team of specialists, given the heterogeneous clinical presentation of the disease.Copyright © 2023 Medical Information Center. All rights reserved.

Acute kidney injury in patient with severe SARS-CoV-2 infection.

Acute kidney injury (AKI) during SARS-CoV-2 infection is frequent and associated with mortality. Pathophysiology of AKI is multifactorial, and encompasses direct (viral invasion, endothelitis and thrombosis, renin-angiotensin-aldosteron system activation, cytokine elevation) and undirect mechanisms (hemodynamic instability, effect of mechanical ventilation, nephrotoxic medications). Acute tubular necrosis is the most frequent histological lesion identified, but glomerular disease can also be observed. To date, there is no specific treatment of SARS-CoV-2 induced AKI.Copyright © SRLF 2021.

Vitamin D and immune response against severe acute respiratory syndrome coronavirus 2 in older adults: Does it really work?

Coronavirus disease 2019 was announced as a pandemic by the WHO on 11 February 2020. Since that time, challenges have arisen regarding the use of supplements to optimally support the immune system in the general population, and especially in older adults. The severity of severe acute respiratory syndrome coronavirus 2 infection varies significantly with age, being generally more severe in geriatric patients. There is evidence supporting the involvement of vitamin D in different processes related to the immune response. Some observational studies have related the decrease in vitamin D levels to the severity of coronavirus disease 2019, suggesting a protective role of vitamin D in this disease. In this narrative review, we analyze the possible role of vitamin D in modulating the immune mechanisms that are activated during severe acute respiratory syndrome coronavirus 2 infection, with special emphasis on older adults.Copyright © 2022 Lippincott Williams and Wilkins. All rights reserved.

Targeting Angiotensin-converting Enzyme 2 (ACE2) for the Discovery of Anticoronaviral Drugs

Coronaviruses are a leading cause of emerging life-threatening diseases, as evidenced by the ongoing coronavirus disease pandemic (COVID-19). According to complete genome sequence analysis reports, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes COVID-19, has a sequence identity highly similar to the earlier severe acute respiratory syndrome coronavirus (SARS-CoV). The SARS-CoV-2 has the same mode of transmission, replication, and pathogenicity as SARS-CoV. The SARS-CoV-2 spike protein's receptor-binding domain (RBD) binds to host angiotensin-converting enzyme-2 (ACE2). The ACE2 is overexpressed in various cells, most prominently epithelial cells of the lung (surface of type 1 and 2 pneumocytes), intestine, liver, kidney, and nervous system. As a result, these organs are more vulnerable to SARS-CoV-2 infection. Furthermore, renin-angiotensin system (RAS) blockers, which are used to treat cardiovascular diseases, intensify ACE2 expression, leading to an increase in the risk of COVID-19. ACE2 hydrolyzes angioten-sin-II (carboxypeptidase) to heptapeptide angiotensin (1-7) and releases a C-terminal amino acid. By blocking the interaction of spike protein with ACE2, the SARS-CoV-2 entry into the host cell and inter-nalization can be avoided. The pathogenicity of SARS-CoV-2 could be reduced by preventing the RBD from attaching to ACE2-expressing cells. Therefore, inhibition or down-regulation of ACE2 in host cells represents a therapeutic strategy to fight against COVID-19. However, ACE2 plays an essential role in the physiological pathway, protecting against hypertension, heart failure, myocardial infarction, acute respiratory lung disease, and diabetes. Given the importance of ACE's homeostatic role, targeting of ACE2 should be realized with caution. Above all, focusing on the SARS-CoV-2 spike protein and the ACE2 gene in the host cell is an excellent way to avoid viral mutation and resistance. The current review summarises the sequence analysis, structure of coronavirus, ACE2, spike protein-ACE2 complex, essential structural characteristics of the spike protein RBD, and ACE2 targeted approaches for anti-coronaviral drug design and development.Copyright © 2022 Bentham Science Publishers.

Polycystic Ovary Syndrome and COVID-19.

Polycystic ovary syndrome (PCOS) is generally characterized by hyperandrogenism, obesity, chronic low-grade inflammation, abnormalities in carbohydrate and lipid metabolism, vit. D deficiency and gut microbiota dysbiosis. Each of the aforementioned disturbances might be considered as a risk factor for increased SARS-CoV-2 susceptibility and more severe COVID-19 infection in women with PCOS. Hyperandrogenism is thought to play an essential role for determining the grade of susceptibility as well as the risk of severe COVID-19 infection in PCOS. It could be explained by the expression of a specific cellular co-receptor - transmembrane serine protease-2 (TMPRSS2), the process of androgen-dependent immune modulation and that of the stimulated renin-angiotensin system (RAS). Android obesity, commonly seen in PCOS, represents a condition of chronic low-grade inflammation that leads to the development of immune dysfunction and increased sensitivity to SARS-CoV-2 among the carriers of this syndrome. In addition, vit. D deficiency and gut dysbiosis have been described as other potential pathophysiological factors contributing to an increased risk for severe COVID-19 in women with PCOS.Copyright © 2022 Medical Information Center. All rights reserved.

Polycystic Ovary Syndrome and COVID-19.

Polycystic ovary syndrome (PCOS) is generally characterized by hyperandrogenism, obesity, chronic low-grade inflammation, abnormalities in carbohydrate and lipid metabolism, vit. D deficiency and gut microbiota dysbiosis. Each of the aforementioned disturbances might be considered as a risk factor for increased SARS-CoV-2 susceptibility and more severe COVID-19 infection in women with PCOS. Hyperandrogenism is thought to play an essential role for determining the grade of susceptibility as well as the risk of severe COVID-19 infection in PCOS. It could be explained by the expression of a specific cellular co-receptor - transmembrane serine protease-2 (TMPRSS2), the process of androgen-dependent immune modulation and that of the stimulated renin-angiotensin system (RAS). Android obesity, commonly seen in PCOS, represents a condition of chronic low-grade inflammation that leads to the development of immune dysfunction and increased sensitivity to SARS-CoV-2 among the carriers of this syndrome. In addition, vit. D deficiency and gut dysbiosis have been described as other potential pathophysiological factors contributing to an increased risk for severe COVID-19 in women with PCOS.Copyright © 2022 Medical Information Center. All rights reserved.

Effect of COVID-19 on Endocrine Glands Function.

A new hitherto unknown virus called severe acute respiratory syndrome coronavirus-2, SARS-CoV-2 for short, the causative agent of the disease COVID-19, has swept the world and become pandemic in its spread. Penetration of the virus into host cells is accomplished by attachment of the spike protein of the virus to its receptor, ACE-2, an enzyme of the renin angiotensin aldosterone system (RAAS), a zinc-dependent carboxypeptidase, which is expressed predominantly in the lung, heart, vascular endothelium, kidney, adipose tissue, thyroid, hypothalamus, pituitary, adrenal pancreas, ovary and testis. SARS-CoV-2 exerts its adverse effects on the function of all endocrine glands, either by direct (viral-toxic) or indirect (immune) mechanisms, with the strength of its action being modulated mainly by hormones of the pituitary-hypothalamic-adrenal axis and also involving the RAAS. This review discusses in detail the impact of SARS-CoV-2 on the endocrine system and possible future complications. The aim is to answer whether SARS-CoV-2 causes endocrine disease per se and whether an increase in the incidence of endocrine disease is expected after rechallenge with COVID-19.Copyright © 2022 Medical Information Center. All rights reserved.

Effect of COVID-19 on Endocrine Glands Function.

A new hitherto unknown virus called severe acute respiratory syndrome coronavirus-2, SARS-CoV-2 for short, the causative agent of the disease COVID-19, has swept the world and become pandemic in its spread. Penetration of the virus into host cells is accomplished by attachment of the spike protein of the virus to its receptor, ACE-2, an enzyme of the renin angiotensin aldosterone system (RAAS), a zinc-dependent carboxypeptidase, which is expressed predominantly in the lung, heart, vascular endothelium, kidney, adipose tissue, thyroid, hypothalamus, pituitary, adrenal pancreas, ovary and testis. SARS-CoV-2 exerts its adverse effects on the function of all endocrine glands, either by direct (viral-toxic) or indirect (immune) mechanisms, with the strength of its action being modulated mainly by hormones of the pituitary-hypothalamic-adrenal axis and also involving the RAAS. This review discusses in detail the impact of SARS-CoV-2 on the endocrine system and possible future complications. The aim is to answer whether SARS-CoV-2 causes endocrine disease per se and whether an increase in the incidence of endocrine disease is expected after rechallenge with COVID-19.Copyright © 2022 Medical Information Center. All rights reserved.

The Significance of Angiotensin-Converting Enzyme-2 (ACE2) in SARS-Cov-2 Infection and COVID-19

The new coronavirus was first reported in 2019 (China) and officially announced by the World Health Organization as a pandemic in March 2020. Severe acute respiratory syndrome coro-navirus 2 (SARS-CoV-2) is the causative agent of the pneumonia-associated illnesses and shares structural homology with the related Severe acute respiratory syndrome coronavirus-1 (SARS-CoV--1). One of the mechanisms for SARS-Cov-1 and-2 infection is mediated by the angiotensin-con-verting enzyme-2 (ACE2) cell receptor, enabling the virus to enter the host cells. ACE2 is an iso-form of the angiotensin-converting enzyme 1 (ACE). The actions of ACE2 counterbalance the clas-sic renin-angiotensin system (RAS) axis through the production of Ang 1-7, which promotes car-diovascular, renal, and lung-protective effects. The ACE2 is not the only route for SARS-CoV-2 to enter the host cells. However, due to its roles in the RAS and its participation in the SARS-CoV-2 virulence, ACE2 has gained attention regarding viral mechanisms of pathogenesis, effects of drugs that interfere with the RAS, and as a potential target for therapeutic strategies for the damages caused by SARS-CoV-2 infection. Among other tissues, ACE2 gene expression seems to be in-creased in the lungs upon SARS-CoV-2 infection;however, amid other variables, expression and/or activity of ACE2 is shown as a disease, sex, and age-dependent. The present review covers critical aspects for a comprehensive understanding of ACE2 and its current involvement in SARS-CoV-2 infection and the development of COVID-19.Copyright © 2021 Bentham Science Publishers.

Beauty and the beast: host microRNA-155 versus SARS-CoV-2.

Severe acute respiratory coronavirus 2 (SARS-CoV-2) infection in the young and healthy usually results in an asymptomatic or mild viral syndrome, possibly through an erythropoietin (EPO)-dependent, protective evolutionary landscape. In the old and in the presence of co-morbidities, however, a potentially lethal coronavirus disease 2019 (COVID-19) cytokine storm, through unrestrained renin-angiotensin aldosterone system (RAAS) hyperactivity, has been described. Multifunctional microRNA-155 (miR-155) elevation in malaria, dengue virus (DENV), the thalassemias, and SARS-CoV-1/2, plays critical antiviral and cardiovascular roles through its targeted translational repression of over 140 genes. In the present review, we propose a plausible miR-155-dependent mechanism whereby the translational repression of AGRT1, Arginase-2 and Ets-1, reshapes RAAS towards Angiotensin II (Ang II) type 2 (AT2R)-mediated balanced, tolerable, and SARS-CoV-2-protective cardiovascular phenotypes. In addition, it enhances EPO secretion and endothelial nitric oxide synthase activation and substrate availability, and negates proinflammatory Ang II effects. Disrupted miR-155 repression of AT1R + 1166C-allele, significantly associated with adverse cardiovascular and COVID-19 outcomes, manifests its decisive role in RAAS modulation. BACH1 and SOCS1 repression creates an anti-inflammatory and cytoprotective milieu, robustly inducing antiviral interferons. MiR-155 dysregulation in the elderly, and in comorbidities, allows unimpeded RAAS hyperactivity to progress towards a particularly aggressive COVID-19 course. Elevated miR-155 in thalassemia plausibly engenders a favorable cardiovascular profile and protection against malaria, DENV, and SARS-CoV-2. MiR-155 modulating pharmaceutical approaches could offer novel therapeutic options in COVID-19.

Primary Aldosteronism and COVID-19-related Management, Disease Severity, and Outcomes: A Retrospective Cohort Study.

Context: The SARS-CoV-2 virus is dependent on components of the renin-angiotensin-aldosterone system for infectivity. Primary aldosteronism (PA) is a form of secondary hypertension mediated by autonomous aldosterone production. The intersection of COVID-19 and PA, both which may involve components of the renin-angiotensin-aldosterone system, remains unknown. Methods: We assessed PA as a risk factor for COVID-19 infection and compared management, severity of disease, and outcomes during COVID-19 with a matched population of patients with essential hypertension (EH) by conducting a retrospective observational cohort study. Results: Of the patients with PA, 81 had a negative PCR test for COVID-19, whereas 43 had a documented positive PCR test for COVID-19. Those patients with PA who tested positive for COVID-19 tended to be female (P = .08) and the majority of those with COVID-19 infection identified as non-White race (P = .02) and Hispanic ethnicity (P = .02). In a subanalysis, 24-hour urine aldosterone on initial PA diagnosis tended to be higher those in the PA group who developed COVID-19 compared with those in the PA group who did not develop COVID-19 [median (interquartile range): 36.5 (16.9, 54.3) vs 22.0 (15.8, 26.8) mcg, P = .049] and was an independent predictor of COVID-19 infection controlling for sex, race, and ethnicity. Angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, and mineralocorticoid receptor antagonist use did not differ between those patients with PA who did and did not have COVID-19 infection. Comparing those patients with PA and matched patients with EH (n = 286) who were COVID-19 PCR positive, there was a significantly higher incidence of cardiovascular complications (12 vs 2%, P = .004) in the PA vs EH group. Conclusion: These data begin to inform us as to whether PA should be a newly identified subpopulation at risk for COVID-19-related cardiovascular disease sequelae.