Expression Of Angiotensin-converting Enzyme 2 Receptor Research Articles

High fat, high sucrose diet promotes increased expression of ACE2 receptor in the SIV-infected host: implications for SARS-CoV-2 infection.

People with pre-existing conditions, including metabolic comorbidities, are at greater risk for complications of SARS-CoV-2 infection and expression of machinery required for viral entry into host cells may be a contributing factor. This study tested the hypothesis that high fat, high sucrose diet (HFSD) and alcohol use increase expression of angiotensin converting enzyme 2 (ACE2) receptor and transmembrane serine protease 2 (TMPRSS2) in tissues isolated from simian immunodeficiency virus (SIV) infected macaques, the most clinically relevant model for the study of HIV. Biospecimens obtained from a longitudinal study of SIV-infected, antiretroviral therapy (ART)-treated female rhesus macaques (Macaca mulatta) were used to determine whether HFSD and chronic binge alcohol (CBA) increased ACE2 and TMPRSS2 protein and gene expression. Macaques (n = 10) were assigned to HFSD or standard diet (SD) for 3 months before CBA or vehicle administration. Three months later, macaques were infected with SIV; ART was initiated 2.5 months thereafter. Tissue samples including lung, pancreas, and kidney were collected at study endpoint (12 months post-SIV infection). Protein expression of ACE2 in the lung, whole pancreas, and pancreatic islets was significantly greater in HFSD- than SD-fed macaques with no significant differences in protein expression of TMPRSS2 or mRNA expression of ACE2 or TMPRSS2. CBA did not significantly alter any measures. The increased ACE2 receptor expression observed in lung and pancreas of SIV-infected HFSD-fed female rhesus macaques aligns with reports that diet may increase susceptibility to COVID-19. These data provide direct evidence for a link between dietary quality and cellular adaptations that may increase the risk for SARS-CoV-2 infection.

Intranasal delivery of PEA-producing Lactobacillus paracasei F19 alleviates SARS-CoV-2 spike protein-induced lung injury in mice

BackgroundSARS-CoV-2 belongs to the coronaviridae family and infects human cells by directly interacting with the angiotensin-converting enzyme-2 (ACE-2) through the viral Spike Protein (SP). While vaccines are crucial, much attention has been directed towards managing the symptoms of acute respiratory distress syndrome. Our present study highlights the potential in counteracting lung inflammation triggered by SARS-CoV-2 SP of the intranasal administration of the engineered probiotic Lactobacillus paracasei F19 expressing the enzyme NAPE-PLD (pNAPE-LP) able to in situ release palmitoylethanolamide (PEA) under a super-low boost of palmitate.MethodsC57BL/6J mice undergo prophylactic treatment with intranasal pNAPE-LP/palmitate for 7 days before a 7 days challenge with intranasal SARS-CoV-2 SP. Then the capability of pNAPE-LP of colonizing the lungs and actively release PEA in situ have been determined by immunofluorescence, western blot and HPLC-MS. Moreover, the innate immune system downregulation and the histological damage rescue exerted by pNAPE-LP have been tested by immunofluorescence, hematoxylin and eosin staining, western blot analysis and ELISA test for the release of the pro-inflammatory mediators.ResultspNAPE-LP effectively colonizes mice lungs and releases the anti-inflammatory compound PEA. Moreover, pNAPE-LP exhibits a protective effect on alveolar morphology, innate immune cells infiltration and in the reduction of neutrophil count, effectively reducing lung injury induced by SARS-CoV-2 SP. This is achieved by mitigating TLR4-mediated NLRP3 activation and the downstream pro-inflammatory products such as ILs, TNFα, C-reactive protein and the myeloperoxidase activity. Interestingly we observed a global reduction ACE2 expression in the lungs.ConclusionpNAPE-LP actively protect from severe inflammatory-related symptoms in SP-challenged mice. Also, it can downregulate the expression of ACE-2 receptors at the lung site potentially preventing the spreading of the infection.

Natural SARS-CoV-2 infection in dogs: Determination of viral loads, distributions, localizations, and pathology

Instances of reverse zoonosis involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented in both controlled experiments and spontaneous cases. Although dogs are susceptible to infection, clinical significance is limited to mild or asymptomatic. Here, we investigate the fatal cases of natural SARS-CoV-2 infection in dogs in Thailand. Pathological findings of SARS-CoV-2-infected dogs reveal severe diffuse alveolar damage, pulmonary hyalinization and fibrosis, and syncytial formation, together with minor lesions in brain and kidney. Employing reverse transcription–digital PCR, substantial viral loads of SARS-CoV-2 were detected in lung, kidney, brain, trachea, tonsil, tracheobronchial lymph node, liver, and intestine, respectively. Localization of SARS-CoV-2 within various tissues was examined through immunohistochemistry (IHC), where the co-localization of the viral spike protein and the angiotensin-converting enzyme 2 (ACE2) receptor was illustrated using double IHC. SARS-CoV-2 localization was markedly identified in the epithelial cells of the lung, trachea, intestine and kidneys, and moderately presented in the salivary gland and gall bladder, where the co-localization with the ACE2 was also evident. Neurons in the brainstem where exhibited lymphocytic perivascular cuffing were also found to be positive for SARS-CoV-2 in IHC testing, despite lacking ACE2 receptor expression. In addition, SARS-CoV-2 replication within the lungs of infected dogs was confirmed by transmission electron microscopy, visualizing free viral particles within the cytosol or the endoplasmic reticulum of syncytial cells within the lung. This study considerably expanded on the knowledge of the pathology associated with natural SARS-CoV-2 infection in dogs, a scenario that is relatively infrequent but occasionally leads to fatal outcome. Furthermore, these findings suggest the potential utility of dogs as a model for studying SARS-CoV-2 infection in humans, warranting further investigation.

ACE-2, TMPRSS2, and Neuropilin-1 Receptor Expression on Human Brain Astrocytes and Pericytes and SARS-CoV-2 Infection Kinetics.

Angiotensin Converting Enzyme 2 (ACE-2), Transmembrane Serine Protease 2 (TMPRSS-2) and Neuropilin-1 cellular receptors support the entry of SARS-CoV-2 into susceptible human target cells and are characterized at the molecular level. Some evidence on the expression of entry receptors at mRNA and protein levels in brain cells is available, but co-expression of these receptors and confirmatory evidence on brain cells is lacking. SARS-CoV-2 infects some brain cell types, but infection susceptibility, multiple entry receptor density, and infection kinetics are rarely reported in specific brain cell types. Highly sensitive Taqman ddPCR, flow-cytometry and immunocytochemistry assays were used to quantitate the expression of ACE-2, TMPRSS-2 and Neuropilin-1 at mRNA and protein levels on human brain-extracted pericytes and astrocytes, which are an integral part of the Blood-Brain-Barrier (BBB). Astrocytes showed moderate ACE-2 (15.9 ± 1.3%, Mean ± SD, n = 2) and TMPRSS-2 (17.6%) positive cells, and in contrast show high Neuropilin-1 (56.4 ± 39.8%, n = 4) protein expression. Whereas pericytes showed variable ACE-2 (23.1 ± 20.7%, n = 2), Neuropilin-1 (30.3 ± 7.5%, n = 4) protein expression and higher TMPRSS-2 mRNA (667.2 ± 232.3, n = 3) expression. Co-expression of multiple entry receptors on astrocytes and pericytes allows entry of SARS-CoV-2 and progression of infection. Astrocytes showed roughly four-fold more virus in culture supernatants than pericytes. SARS-CoV-2 cellular entry receptor expression and "in vitro" viral kinetics in astrocytes and pericytes may improve our understanding of viral infection "in vivo". In addition, this study may facilitate the development of novel strategies to counter the effects of SARS-CoV-2 and inhibit viral infection in brain tissues to prevent the spread and interference in neuronal functions.

Angiotensin-Converting Enzyme 2 Expression and Severity of SARS-CoV-2 Infection.

Angiotensin-converting enzyme 2 (ACE2), first discovered in 2000, serves as an important counterregulatory enzyme to the angiotensin II-mediated vasoconstrictive, pro-inflammatory, and pro-fibrotic actions of the renin-angiotensin system (RAS). Conversion of angiotensin II to the peptide angiotensin 1-7 (ANG 1-7) exerts protective vasodilatory, anti-inflammatory, and anti-fibrotic actions through interaction with the MasR receptor. There are many important considerations when noting the role of ACE2 in the pathogenesis and sequelae of COVID-19 infection. ACE2, in the role of COVID-19 infection, was recognized early in 2020 at the beginning of the pandemic as a cell membrane-bound and soluble binding site for the viral spike protein facilitating entering into tissue cells expressing ACE2, such as the lungs, heart, gut, and kidneys. Mechanisms exist that alter the magnitude of circulating and membrane-bound ACE2 (e.g., SARS-CoV-2 infection, viral variants, patient characteristics, chronic disease states, and the degree of cell surface expression of ACE2) and the influence these mechanisms have on the severity of disease and associated complications (e.g., respiratory failure, systemic inflammatory response syndrome, acute myocarditis, acute kidney injury). Several medications alter the ACE2 receptor expression, but whether these medications can influence the course of the disease and improve outcomes is unclear. In this review, we will discuss what is known about the interrelation of SARS-CoV-2, ACE2 and the factors that may contribute to the variability of its expression and potential contributors to the severity of COVID-19 infection.

Association of COVID-19 with Comorbidities: An Update.

Coronavirus disease (COVID-19) is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) which was identified in Wuhan, China in December 2019 and jeopardized human lives. It spreads at an unprecedented rate worldwide, with serious and still-unfolding health conditions and economic ramifications. Based on the clinical investigations, the severity of COVID-19 appears to be highly variable, ranging from mild to severe infections including the death of an infected individual. To add to this, patients with comorbid conditions such as age or concomitant illnesses are significant predictors of the disease's severity and progression. SARS-CoV-2 enters inside the host cells through ACE2 (angiotensin converting enzyme2) receptor expression; therefore, comorbidities associated with higher ACE2 expression may enhance the virus entry and the severity of COVID-19 infection. It has already been recognized that age-related comorbidities such as Parkinson's disease, cancer, diabetes, and cardiovascular diseases may lead to life-threatening illnesses in COVID-19-infected patients. COVID-19 infection results in the excessive release of cytokines, called "cytokine storm", which causes the worsening of comorbid disease conditions. Different mechanisms of COVID-19 infections leading to intensive care unit (ICU) admissions or deaths have been hypothesized. This review provides insights into the relationship between various comorbidities and COVID-19 infection. We further discuss the potential pathophysiological correlation between COVID-19 disease and comorbidities with the medical interventions for comorbid patients. Toward the end, different therapeutic options have been discussed for COVID-19-infected comorbid patients.

Tissue distribution of angiotensin-converting enzyme 2 (ACE2) receptor in wild animals with a focus on artiodactyls, mustelids and phocids

Natural cases of zooanthroponotic transmission of SARS-CoV-2 to animals have been reported during the COVID-19 pandemic, including to free-ranging white-tailed deer (Odocoileus virginianus) in North America and farmed American mink (Neovison vison) on multiple continents. To understand the potential for angiotensin-converting enzyme 2 (ACE2)-mediated viral tropism we characterised the distribution of ACE2 receptors in the respiratory and intestinal tissues of a selection of wild and semi-domesticated mammals including artiodactyls (cervids, bovids, camelids, suids and hippopotamus), mustelid and phocid species using immunohistochemistry. Expression of the ACE2 receptor was detected in the bronchial or bronchiolar epithelium of several European and Asiatic deer species, Bactrian camel (Camelus bactrianus), European badger (Meles meles), stoat (Mustela erminea), hippopotamus (Hippopotamus amphibious), harbor seal (Phoca vitulina), and hooded seal (Cystophora cristata). Further receptor mapping in the nasal turbinates and trachea revealed sparse ACE2 receptor expression in the mucosal epithelial cells and occasional occurrence in the submucosal glandular epithelium of Western roe deer (Capreolus capreolus), moose (Alces alces alces), and alpaca (Vicunga pacos). Only the European badger and stoat expressed high levels of ACE2 receptor in the nasal mucosal epithelium, which could suggest high susceptibility to ACE2-mediated respiratory infection. Expression of ACE2 receptor in the intestinal cells was ubiquitous across multiple taxa examined. Our results demonstrate the potential for ACE2-mediated viral infection in a selection of wild mammals and highlight the intra-taxon variability of ACE2 receptor expression, which might influence host susceptibility and infection.

Genitourinary tract symptoms in patients admitted with COVID-19: Exploring changes in frequency by determinants and pandemic waves

Background:Urothelial cells exhibit increased expression of angiotensin-converting enzyme-2 receptor, which is the binding site of severe acute respiratory syndrome coronavirus 2 to cells. The frequency and distribution of genitourinary tract symptoms in patients diagnosed with coronavirus disease 2019 (COVID-19) is unknown. Objective:We explored trends in genitourinary tract symptoms by gender and each of six pandemic waves in patients admitted for COVID-19, and related them with severity, death and length of hospitalization. Design, Setting, and Participants:A retrospective study took place in our institution of COVID-19 admitted patients. Only patients with RT-PCR or antigen test confirmed SARS-CoV-2 infection were included. Demographic, clinical, and genitourinary symptoms were explored. Outcome Measurements and Statistical Analysis:COVID-19 patients with genitourinary tract symptoms were compared with those without. Statistical comparisons were conducted by parametric and nonparametric tests for quantitative variables, and χ2 test for qualitative variables. Results and limitations:Out of a total of 4,661 COVID-19 patients, genitourinary symptoms were found in 21,1%. These symptoms were more frequent in patients admitted for longer than 30 days, except for urinary incontinence (UI) and erectile dysfunction (ED). Acute kidney injury (AKI) and urinary tract infections (UTI) had a higher presence in the 5th (16.7%; 12.8% respectively) and 3rd wave (13.3%; 12.6% respectively). Genitourinary symptoms were higher for those patients admitted in critical care units. Frequency of AKI, UI, UTI and acute urinary retention (AUR) were higher for patients who were finally deceased (26.2%; 3.5%; 13.6% and 3.6% respectively). Conclusions:A high frequency of genitourinary symptoms in patients admitted for COVID-19 was observed, whose frequency and distribution varied according to pandemic waves. Specific genitourinary conditions were associated with worse outcomes and poorer prognosis.

A modern view on the clinical value of the study of oral fluid in the practice of a pediatrician

Currently, the attention of the medical community to a non-invasive method of laboratory diagnostics - the study of oral fluid (oral, saliva, saliva test) in various fields of clinical medicine and mainly in adult patients has been updated. Saliva testing has shown good results, especially in the areas of genomics, microbiomics, proteomics, metabolomics, and transcriptomics. The review presents the possibilities of using a non-invasive method for infectious and non-infectious diseases in children. Saliva contains a wide range of protein DNA and RNA biomarkers that help detect many viral infections in children. Oral fluid tests for human immunodeficiency virus, hepatitis B virus have improved access to diagnostics for infants. Both serological and molecular analyzes of the oral fluid are suitable for routine examination and early detection of measles virus RNA, polyomaviruses. Angiotensin-converting enzyme-2 receptor expression was found in the saliva of children with COVID-19, which can be used to diagnose SARS-CoV-2. The saliva test is as effective as the standard test at identifying asymptomatic individuals in contact tracing. The possibilities of saliva diagnostics are positively assessed in transplantology. New biomarkers in saliva have been identified for the diagnosis of many somatic diseases in children. The role of oral fluid as an alternative to blood serum in patients with terminal renal failure, chronic kidney disease (determination of creatinine, urea) in both adults and children is shown. The data obtained may influence the recommendations for the treatment of patients. As a non-invasive method, the study of oral fluid is promising for the diagnosis, prognosis, monitoring of diseases, large-scale typing of children, and the search for new biomarkers.

Correlation between structural heart disease and cardiac SARS-CoV-2 manifestations

Background:The prognosis of COVID-19 patients with cardiac involvement is unfavorable and it remains unknown which patients are at risk. The virus enters cells via its receptor angiotensin-converting enzyme 2 (ACE2). Myocardial ACE2 expression is increased in structural heart disease (SHD). We, therefore, aimed to analyze correlations between structural heart disease and cardiac SARS-CoV-2 manifestation.Methods:The clinical course of COVID-19 in patients with structural heart disease was assessed in a prospective cohort of 152 patients. The primary endpoints consisted of hospitalization and survival. Cardiac tissue of 23 autopsy cases with lethal COVID-19 course was obtained and analyzed for (a) the presence of SHD, (b) myocardial presence of SARS-CoV-2 via RT,-PCR, and (c) levels of ACE2 expression using immunofluorescence staining.Results:Structural heart disease is found in 67 patients, of whom 56 (83.60%) are hospitalized. The myocardium is positive for SARS-CoV-2 in 15 patients (65%) in 23 autopsy cases of lethal COVID-19. Moreover, most hearts with evidence of myocardial SARS-CoV-2 have structural heart disease [11 (91,67%) vs. 1 (8,33%), p = 0.029]. Myocardial presence of SARS-CoV-2 is correlated with a significant downregulation of ACE2 compared to negative control hearts (6.545 ± 1.1818 A.U. vs. 7.764 ± 2.411 A.U., p = 0.003). The clinical course of patients with cardiac SARS-CoV-2 manifestation is unfavorable, resulting in impaired survival (median, 12 days and 4.5 days, respectively, HR 0.30, 95% CI, 0.13 to 0.73, p = 0.0005)Conclusions:We provide evidence for a correlation between SHD, altered ACE2 receptor expression, and cardiac SARS-CoV-2 manifestation. Consequently, structural heart disease may be considered a distinct risk factor for a severe clinical course after infection with SARS-CoV-2.Registration number local IRB:Ethics Committee of Northwestern and Central Switzerland ID 2020-00629; Ethics Committee of the Medical University Innsbruck EK Nr: 1103/2020.ClinicalTrials.gov number:NCT04416100.

HCV Infection Increases the Expression of ACE2 Receptor, Leading to Enhanced Entry of Both HCV and SARS-CoV-2 into Hepatocytes and a Coinfection State.

Recent studies suggest the enhancement of liver injury in COVID-19 patients infected with Hepatitis C virus (HCV). Hepatocytes express low levels of angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor, raising the possibility of HCV-SARS-CoV-2 coinfection in the liver. This work aimed to explore whether HCV and SARS-CoV-2 coinfect hepatocytes and the interplay between these viruses. We demonstrate that SARS-CoV-2 coinfects HCV-infected Huh7.5 (Huh7.5HCV) cells. Both viruses replicated efficiently in the coinfected cells, with HCV replication enhanced in coinfected compared to HCV-mono-infected cells. Strikingly, Huh7.5HCV cells were eight fold more susceptible to SARS-CoV-2 pseudoviruses than naive Huh7.5 cells, suggesting enhanced SARS-CoV-2 entry into HCV-preinfected hepatocytes. In addition, we observed increased binding of spike receptor-binding domain (RBD) protein to Huh7.5HCV cells, as well as enhanced cell-to-cell fusion of Huh7.5HCV cells with spike-expressing Huh7.5 cells. We explored the mechanism of enhanced SARS-CoV-2 entry and identified an increased ACE2 mRNA and protein levels in Huh7.5HCV cells, primary hepatocytes, and in data from infected liver biopsies obtained from database. Importantly, higher expression of ACE2 increased HCV infection by enhancing its binding to the host cell, underscoring its role in the HCV life cycle as well. Transcriptome analysis revealed that shared host signaling pathways were induced in HCV-SARS-CoV-2 coinfection. This study revealed complex interactions between HCV and SARS-CoV-2 infections in hepatocytes, which may lead to the increased liver damage recently reported in HCV-positive COVID-19 patients. IMPORTANCE Here, we provide the first experimental evidence for the coexistence of SARS-CoV-2 infection with HCV, and the interplay between them. The study revealed a complex relationship of enhancement between the two viruses, where HCV infection increased the expression of the SARS-CoV-2 entry receptor ACE2, thus facilitating SARS-CoV-2 entry, and potentially, also HCV entry. Thereafter, SARS-CoV-2 infection enhanced HCV replication in hepatocytes. This study may explain the aggravation of liver damage that was recently reported in COVID-19 patients with HCV coinfection and suggests preinfection with HCV as a risk factor for severe COVID-19. Moreover, it highlights the possible importance of HCV treatment for coinfected patients. In a broader view, these findings emphasize the importance of identifying coinfecting pathogens that increase the risk of SARS-CoV-2 infection and that may accelerate COVID-19-related co-morbidities.

Electroacupuncture preconditioning improves pulmonary function via inhibiting inflammatory response and up-regulating expression of ACE2 and Ang (1-7) in lipopolysaccharide-induced acute lung injury rats

To observe the effect of electroacupuncture (EA) at "Zusanli"(ST36) pretreatment on lung functions, inflammatory response, and levels of angiotensin-converting enzyme 2 (ACE2) and angiotensin (1-7) ［Ang (1-7)］ in rats with sepsis-induced acute lung injury (ALI), so as to explore its mechanisms underlying improvement of ALI. Thirty male SD rats were randomly divided into normal, model and EA groups (n=10 in each group). The sepsis-related ALI model was established by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). Rats of the EA group received EA (4 Hz/20 Hz, 1-3 mA) stimulation at bilateral ST36 for 30 min, once each day, for 7 days before modeling. The lung functions including forced vital capacity (FVC), forced expiratory volume at 0.1 second (FEV0.1) and FEV0.3 were detected using a respiratory function detector for small animals at 3 h after modeling. The bronchoalveolar lavage fluid (BALF) was collected for assaying the contents of Ang (1-7), tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) using ELISA. The lung wet/dry weight (W/D) ratio, FEV0.1/FVC, and FEV0.3/FVC were calculated. The histopathological changes of lung tissues were displayed by hematoxylin-eosin (H.E.) staining. The expression of ACE2 and mitochondrial assembly receptor (MasR) mRNAs and proteins in the lung tissue was detected by fluorescence quantitative real-time PCR and Western blot, separately. Following modeling, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and the expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly decreased (P<0.01), while the level of W/D ratio and TNF-α and IL-1β contents in the BALF significantly increased (P<0.01) in the model group relevant to the normal group. In comparison with the model group, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly increased (P<0.05, P<0.01), whereas the level of W/D ratio, and TNF-α and IL-1β contents in the BALF were significantly decreased (P<0.05, P<0.01) in the EA group. H.E. staining showed pulmonary interstitial edema and alveolar septum thickening with severe inflammatory cell infiltration in the model group, which was relatively milder in the EA group. EA preconditioning at ST36 can improve pulmonary function in sepsis-related ALI rats, which may be related to its effects in inhibiting inflammatory response and up-regulating ACE2 and MasR expression and Ang (1-7) content in the lung tissue.

Vitamin D and interferon-γ co-operate to increase the ACE-2 receptor expression in primary cultures of human thyroid cells.

BackgroundA more severe course of COVID-19 was associated with low levels of Vitamin D (VitD). Moreover in vitro data showed that VitD up-regulates the mRNA of the Angiotensin Converting Enzyme 2 (ACE-2), the SARS-COV-2 receptor in different type of cells. ACE-2 is expressed in several type of tissues including thyroid cells, on which its mRNA was shown to be up-regulated by interferon-gamma (IFN-γ). The aim of the present study was to investigate if treatment with VitD alone or in combination with IFN-γ would increase ACE-2 both at mRNA and protein levels in primary cultures of human thyrocytes.Materials and methodsPrimary thyroid cell cultures were treated with VitD and IFN-γ alone or in combination for 24 h. ACE-2 mRNA levels were measured by Real-time Polymerase Chain Reaction (RT-PCR). The presence of ACE-2 on thyroid cell membrane was assessed by immunocytochemistry basally and after the previous mentioned treatments.ResultsACE-2 mRNA levels increased after treatment with VitD and IFN-γ alone. The combination treatment (VitD + IFN-γ) showed an additive increase of ACE-2-mRNA. Immunocytochemistry experiments showed ACE-2 protein on thyroid cells membrane. ACE-2 expression increased after treatment with VitD and IFN-γ alone and further increased by the combination treatment with VitD + IFN-γ.ConclusionsVitD would defend the body by SARS-COV2 both by regulating the host immune defense and by up-regulating of the expression of the ACE-2 receptor. The existence of a co-operation between VitD and IFN-γ demonstrated in other systems is supported also for ACE-2 up-regulation. These observations lead to an increased interest for the potential therapeutic benefits of VitD supplementation in COVID-19.

Angiotensin-converting enzyme 2 and transmembrane protease serine 2 in female and male patients with end-stage kidney disease.

BackgroundIndividuals with chronic kidney disease are affected by acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) due to multiple comorbidities and altered immune system. The first step of the infection process is the binding of SARS‐CoV‐2 with angiotensin‐converting enzyme 2 (ACE2) receptor, followed by its priming by transmembrane protease serine 2 (TMPRSS2). We hypothesized that circulating soluble ACE2 levels, as well as the expressions of ACE2 and TMPRSS2 in the microvasculature, are increased in patients with end‐stage kidney disease (ESKD).MethodsA total of 210 participants were enrolled, representing 80 ESKD patients and 73 non‐CKD controls for soluble ACE2, and 31 ESKD and 26 non‐CKD controls for vasculature and fat tissue bioassays. We have assessed ACE2 expression in blood using ELISA and in tissue using immunofluorescence.ResultsSoluble ACE2 levels were higher in ESKD patients compared to controls; however, there is no sex difference observed. In ESKD and controls, soluble ACE2 positively correlated with Interleukin 6 (IL‐6) and C‐reactive protein (CRP), respectively. Similarly, ACE2 tissue expression in the vasculature was higher in ESKD patients; moreover, this higher ACE2 expression was observed only in male ESKD patients. In addition, TMPRSS2 expression was observed in vessels from males and females but showed no sex difference. The expression of ACE2 receptor was higher in ESKD patients on ACE‐inhibitor/angiotensin blocker treatment.ConclusionESKD is associated with increased ACE2 levels in the circulation and pronounced in male vasculature; however, further studies are warranted to assess possible sex differences on specific treatment regime(s) for different comorbidities present in ESKD.

Ramipril Reduces Acylcarnitines and Distinctly Increases Angiotensin-Converting Enzyme 2 Expression in Lungs of Rats.

The angiotensin-converting enzyme 2 (ACE2) receptor has been identified as the entry receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is abundantly expressed in many organs. With respect to the role of circulating ACE2 and its receptor expression in the pathogenesis of the SARS-CoV-2 infection, it is still debated whether diseases such as hypertension or pharmacotherapies, including ACE inhibitors and angiotensin receptor blockers that affect ACE2 receptor expression, may modulate the severity and outcome of the coronavirus disease 2019 (COVID-19). We therefore tested the hypothesis that treatment with the ACE inhibitor Ramipril affects organ-specific ACE2 receptor mRNA and protein expression as well as the serum metabolome in BioBreeding (BB) rats. Twelve male BioBreeding rats were randomly divided into a Ramipril (10 mg/kg body weight) treatment group or a control group (N = 12; n = 6 per group) over a period of seven days. Ramipril treatment resulted in the reduction of acylcarnitines (C3–C6) out of 64 metabolites. Among the different organs studied, only in the lungs did Ramipril treatment significantly increase both Ace2 mRNA and ACE2 receptor membrane protein levels. Increased ACE2 receptor lung expression after Ramipril treatment was not associated with differences in ACE2 serum concentrations between experimental groups. Our data provide experimental in vivo evidence that the ACE inhibitor Ramipril selectively increases pulmonary ACE2 receptor mRNA and protein levels and reduces acylcarnitines.

Smoking and COVID-19

&lt;p&gt;新型冠狀病毒肺炎（簡稱新冠肺炎）是本世紀最重要的傳染病。許多研究已經證實吸菸抑制肺部免疫力，增加呼吸道傳染性疾病風險。早期新冠肺炎的研究對吸菸的資料較少，中國學者發表的研究及美國哈佛大學團隊發表的研究，皆顯示吸菸的新冠肺炎病人約有兩倍的風險發展為重症。最早的統合分析研究顯示吸菸與新冠肺炎重症無統計學顯著相關，亦有少數學者報告新冠肺炎病人吸菸率低於人口平均值，導致「尼古丁保護論」的產生。然而後續學者的論文指出最初的統合分析有數據引用及統計方法的錯誤，經更正後吸菸與新冠肺炎重症應有統計學顯著相關。人口學研究方面，使用統合回歸及時空模型等方法，顯示吸菸率較高的地區新冠肺炎發生率較高。美國克里夫蘭醫學中心分析吸菸量與新冠肺炎預後的關係，發現吸菸量越高，新冠肺炎住院、入住加護病房及死亡率皆越高，顯示有劑量效應，進一步推論有因果關係。英國約42萬人的Biobank發表結合流行病學及基因研究的資料，亦顯示吸菸與新冠肺炎重症有因果關係。在致病機轉方面，吸菸增加ACE2(angiotensin converting enzyme-2)受體的表現，導致感染率較高。吸菸也增加手口接觸的機會，提高接觸傳染的風險。在大型的統合分析方面，有數萬人的研究證實除了年齡、高血壓、糖尿病、心血管疾病、慢性阻塞性肺病、慢性腎病以外，吸菸增加住院病人死亡的風險。本文結論吸菸增加新冠肺炎感染、重症及死亡的風險，吸菸者應盡速戒菸。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;COVID-19 is one of the most prevalent infectious diseases in this century. While many studies have proved that smoking suppresses pulmonary immunity and increases the risk of lung infections, there are fewer reports on the association between smoking and the severity of COVID-19 infection. Studies of both Chinese researchers and a Harvard University research team revealed that the risk of developing severe outcomes doubled in smoking COVID-19 patients. The first meta-analysis showed that there was no statistically significant effect of smoking on developing severe COVID-19 outcomes, and the report of several researchers that the smoking rate of COVID-19 patients was lower than that of the general population even led to the emergency of the &amp;ldquo;nicotine protection&amp;rdquo; theory. However, subsequent studies found the data collection and analysis methods of the first meta-analysis invalid. The corrected analysis indicated a statistically significant correlation between smoking and the severity of COVID-19 outcomes. Population studies using meta-regression and spatiotemporal models also identified a higher COVID-19 prevalence in areas with higher smoking rates. According to the COVID-19 registry developed by the US-based Cleveland Clinic, greater smoking exposure was associated with higher rates of COVID-19 hospitalization, ICU admission, and mortality. The results unveiled a dose-response relationship indicating the causal effect of smoking and COVID-19 outcomes. The UK Biobank recruited around 420,000 participants, and a combination of epidemiology and genetic studies concluded the causal effect of smoking on the risk of severe COVID-19 outcomes. As reported by studies on transmission mechanisms, smoking increased the expression of ACE2 (angiotensin converting enzyme-2) receptors, thereby increasing the risk of infection. Hand and mouth contact during smoking was also a risk to increase viral transmission. In a large-scale meta-analysis that studied tens of thousands of patients, in addition to hypertension, diabetes, cardiovascular diseases, COPD, and chronic renal diseases, smoking was one of the in-hospital mortality risks. This review article concludes that smoking increases the risks of infection, severe outcomes, and mortality of COVID-19. Smokers are urged to stop smoking as soon as possible.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Vitamin D Inhibits IL-6 Pro-Atherothrombotic Effects in Human Endothelial Cells: A Potential Mechanism for Protection against COVID-19 Infection?

Background: Thrombosis with cardiovascular involvement is a crucial complication in COVID-19 infection. COVID-19 infects the host by the angiotensin converting enzyme-2 receptor (ACE2r), which is expressed in endothelial cells too. Thus, COVID-related thrombotic events might be due to endothelial dysfunction. IL-6 is one of the main cytokines involved in the COVID-19 inflammatory storm. Some evidence indicates that Vitamin D (VitD) has a protective role in COVID-19 patients, but the molecular mechanisms involved are still debated. Thus, we investigated the effect of VitD on Tissue Factor and adhesion molecules (CAMs) in IL-6-stimulated endothelial cells (HUVEC). Moreover, we evaluated levels of the ACE2r gene and proteins. Finally, we studied the modulation of NF-kB and STAT3 pathways. Methods: HUVEC cultivated in VitD-enriched medium were stimulated with IL-6 (0.5 ng/mL). The TF gene (RT-PCR), protein (Western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. Similarly, CAMs soluble values (ELISA) and ACE2r (RT-PCR and Western blot) levels were assessed. NF-kB and STAT3 modulation (Western blot) were also investigated. Results: VitD significantly reduced TF expression at both gene and protein levels as well as TF-procoagulant activity in IL-6-treated HUVEC. Similar effects were observed for CAMs and ACE2r expression. IL-6 modulates these effects by regulating NF-κB and STAT3 pathways. Conclusions: IL-6 induces endothelial dysfunction with TF and CAMs expression via upregulation of ACE2r. VitD prevented these IL-6 deleterious effects. Thus, it might be speculated that this is one of the hypothetical mechanism(s) by which VitD exerts its beneficial effects in COVID-19 infection.

COVID-19 Infections and Asthma

The severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), has infected more than 200 million and led to the deaths of more than 4.3 million people. Although there are known risk factors for severe disease, asthma was initially hypothesized to be a risk factor for severe disease given the association between asthma exacerbations and respiratory viral illnesses in general. Fortunately, clinical outcomes for patients with asthma overall are similar to those for patients without asthma, without convincing evidence that asthma is a risk factor for severe disease. This may be explained in part by the decreasing gradient of angiotensin-converting enzyme-2 receptor from the upper to lower respiratory epithelium and that aeroallergen-sensitized patients with asthma can have up to 50% reduction in angiotensin-converting enzyme-2 receptor expression. Vaccination for patients with asthma is recommended for all without clear contraindications. COVID-19–specific treatment options are available depending on the severity of disease. We caution the use of systemic corticosteroids in patients with asthma not requiring supplemental oxygen given an association with worse outcomes. Postacute COVID-19 syndrome or long-haul COVID does not appear to be more prevalent in the population with asthma, and a multidisciplinary approach to care is a reasonable option.

Evaluation of Macular Retinal Vessels and Histological Changes in Two Cases of COVID-19.

The purpose of this study was to assess vascular and histological alterations in two COVID-19 and three control post-mortem retinas. The macular areas of flat-mounted samples were processed for immunofluorescence. Lectin and collagen IV positive vessels were captured under confocal microscopy, and endothelium loss and tortuosity were analyzed. Expression of ACE2 (angiotensin-converting enzyme 2) (the receptor for SARS-CoV-2), Iba1 (ionized calcium-binding adaptor molecule 1) and GFAP (glial fibrillary acidic protein) were quantified in retinal sections. The number of lectin vessels in COVID-19 retinas decreased by 27% compared to the control (p < 0.01) and the tortuosity increased in COVID-19 retinas (7.3 ± 0.2) vs. control retinas (6.8 ± 0.07) (p < 0.05). Immunofluorescence analysis revealed an increase in ACE2 (2.3 ± 1.3 vs. 1.0 ± 0.1; p < 0.0001) and Iba1 expression (3.06 ± 0.6 vs. 1.0 ± 0.1; p < 0.01) in COVID-19 sections whereas no changes in GFAP were observed. Analysis of the COVID-19 macular retinal tissue suggested that endothelial cells are a preferential target of SARS-CoV-2 with subsequent changes through their ACE2 receptor expression and morphology. Thus, microglial activation was hyperactive when facing an ensuing immunological challenge after SARS-CoV-2 infection.

Trigeminal neuralgia post COVID-19: Preliminary report and clinical consideration

COVID-19 is a single RNA virus that enters the host cells after binding to the Angiotensin-converting enzyme 2 (ACE2). The symptomatic picture of SARS-CoV-2 is dominated by respiratory disease. However, the spread of the virus, is not circumscribed considering that ACE2 receptor expression is also detected in other tissues, including the CNS. Neurological impairment is more likely in patients with more severe infection, and the most frequently encountered neurological pathologies were acute cerebrovascular disease, impaired consciousness, and impaired taste and sense of smell.