ACE2 Expression Research Articles

Sustained ACE2 Expression by Probiotic Improves Integrity of Intestinal Lymphatics and Retinopathy in Type 1 Diabetic Model.

Intestinal lymphatic, known as lacteal, plays a critical role in maintaining intestinal homeostasis by regulating several key functions, including the absorption of dietary lipids, immune cell trafficking, and interstitial fluid balance in the gut. The absorption of dietary lipids relies on lacteal integrity, mediated by button-like and zipper-like junctions. Although the intestinal lymphatic system is well studied in many diseases, including obesity, the contribution of lacteals to the gut-retinal axis in type 1 diabetes (T1D) has not been examined. Previously, we showed that diabetes induces a reduction in intestinal angiotensin-converting enzyme 2 (ACE2), leading to gut barrier disruption. However, when ACE2 levels are maintained, a preservation of gut barrier integrity occurs, resulting in less systemic inflammation and a reduction in endothelial cell permeability, ultimately retarding the development of diabetic complications, such as diabetic retinopathy. Here, we examined the impact of T1D on intestinal lymphatics and circulating lipids and tested the impact of intervention with ACE-2-expressing probiotics on key aspects of gut and retinal function. Akita mice with 6 months of diabetes were orally gavaged LP-ACE2 (3x/week for 3 months), an engineered probiotic (Lactobacillus paracasei; LP) expressing human ACE2. After three months, immunohistochemistry (IHC) was used to evaluate intestinal lymphatics, gut epithelial, and endothelial barrier integrity. Retinal function was assessed using visual acuity, electroretinograms, and enumeration of acellular capillaries. LP-ACE2 significantly restored intestinal lacteal integrity as assessed by the increased expression of lymphatic vessel hyaluronan receptor 1 (LYVE-1) expression in LP-ACE2-treated Akita mice. This was accompanied by improved gut epithelial (Zonula occludens-1 (ZO-1), p120-catenin) and endothelial (plasmalemma vesicular protein -1 (PLVAP1)) barrier integrity. In Akita mice, the LP-ACE2 treatment reduced plasma levels of LDL cholesterol and increased the expression of ATP-binding cassette subfamily G member 1 (ABCG1) in retinal pigment epithelial cells (RPE), the population of cells responsible for lipid transport from the systemic circulation into the retina. LP-ACE2 also corrected blood-retinal barrier (BRB) dysfunction in the neural retina, as observed by increased ZO-1 and decreased VCAM-1 expression compared to untreated mice. LP-ACE2-treated Akita mice exhibit significantly decreased numbers of acellular capillaries in the retina. Our study supports the beneficial role of LP-ACE2 in the restoration of intestinal lacteal integrity, which plays a key role in gut barrier integrity and systemic lipid metabolism and decreased diabetic retinopathy severity.

Variation in COVID-19 mortality rate across populations, polymorphism in genes, and gender-associated genetic patterns

A severe onset of COVID-19 leads to death due to respiratory failure and ARDS is the common finding of lung histopathology in different people with different comorbidities. It can invade the nervous system leading to the manifestation of neurological symptoms and brain damage including encephalitis and stroke. Genetic polymorphism, comorbidities, and gender differences is playing a pivotal role in conferring resistance and susceptibility to COVID-19. Despite almost the same ACE2 expression profile in males and females, males have shown a high mortality rate due to higher expression of TMPRSS2 (pivotal for S protein binding) as these genes are androgen responsive. While women have shown higher expression of ADAM17, ADAM10 genes are associated with the shedding of ACE2 receptors and are estrogen-responsive, leading to low levels of membrane-bound ACE2 which is indispensable for SARS-Cov2 entry into the cell. People with blood Groups A, and AB are comparatively more susceptible to COVID-19 than people with blood group O, the reason for the O group is attributed to the presence of Anti A antibodies.

Human ACE2 expression, a major tropism determinant for SARS-CoV-2, is regulated by upstream and intragenic elements.

Angiotensin-converting enzyme 2 (ACE2), part of the renin-angiotensin system (RAS), serves as an entry point for SARS-CoV-2, leading to viral proliferation in permissive cell types. Using mouse lines in which the Ace2 locus has been humanized by syntenic replacement, we show that regulation of basal and interferon induced ACE2 expression, relative expression levels of different ACE2 transcripts, and sexual dimorphism in ACE2 expression are unique to each species, differ between tissues, and are determined by both intragenic and upstream promoter elements. Our results indicate that the higher levels of expression of ACE2 observed in the lungs of mice relative to humans may reflect the fact that the mouse promoter drives expression of ACE2 in populous airway club cells while the human promoter drives expression in alveolar type 2 (AT2) cells. In contrast to transgenic mice in which human ACE2 is expressed in ciliated cells under the control of the human FOXJ1 promoter, mice expressing ACE2 in club cells under the control of the endogenous Ace2 promoter show a robust immune response after infection with SARS-CoV-2, leading to rapid clearance of the virus. This supports a model in which differential expression of ACE2 determines which cell types in the lung are infected, and this in turn modulates the host response and outcome of COVID-19.

Sexual Dimorphism in the Expression of Cardiac and Hippocampal Renin-Angiotensin and Kallikrein–Kinin Systems in Offspring from Mice Exposed to Alcohol during Gestation

Prenatal alcohol exposure (PAE) impairs fetal development. Alcohol consumption was shown to modulate the renin-angiotensin system (RAS). This study aimed to analyze the effects of PAE on the expression of the renin-angiotensin system (RAS) and kallikrein-kinin system (KKS) peptide systems in the hippocampus and heart of mice of both sexes. C57Bl/6 mice were exposed to alcohol during pregnancy at a concentration of 10% (v/v). On postnatal day 45 (PN45), mouse hippocampi and left ventricles (LV) were collected and processed for messenger RNA (mRNA) expression of components of the RAS and KKS. In PAE animals, more pronounced expression of AT1 and ACE mRNAs in males and a restored AT2 mRNA expression in females were observed in both tissues. In LV, increased AT2, ACE2, and B2 mRNA expressions were also observed in PAE females. Furthermore, high levels of H2O2 were observed in males from the PAE group in both tissues. Taken together, our results suggest that modulation of the expression of these peptidergic systems in PAE females may make them less susceptible to the effects of alcohol.

Comprehensive analysis of SARS-CoV-2 receptor proteins in human respiratory tissues identifies alveolar macrophages as potential virus entry site.

COVID-19 has had enormous consequences on global health-care and has resulted in millions of fatalities. The exact mechanism and site of SARS-CoV-2 entry into the body remains insufficiently understood. Recently, novel virus receptors were identified, and alveolar macrophages were suggested as a potential viral entry cell type and vector for intra-alveolar virus transmission. Here, we investigated the protein expression of 10 well-known and novel virus entry molecules along potential entry sites in humans using immunohistochemistry. Samples of different anatomical sites from up to 93 patients were incorporated into tissue microarrays. Protein expression of ACE2, TMPRSS2, furin, CD147, C-type lectin receptors (CD169, CD209, CD299), neuropilin-1, ASGR1 and KREMEN1 were analysed. In lung tissues, at least one of the three receptors ACE2, ASGR1 or KREMEN1 was expressed in the majority of cases. Moreover, all the investigated molecules were found to beexpressed in alveolar macrophages, and co-localisation with SARS-CoV-2 N-protein was demonstrated using dual immunohistochemistry in lung tissue from a COVID-19 autopsy. While CD169 and CD209 showed consistent protein expression in sinonasal, conjunctival and bronchiolar tissues, neuropilin-1 and ASGR1 were mostly absent, suggesting a minor relevance of these two molecules at these specific sites. Our results extend recent discoveries indicating a role for these molecules in virus entry at different anatomical sites. Moreover, they support the notion of alveolar macrophages being a potential entry cell for SARS-CoV-2.

CDK4/6 inhibitor palbociclib promotes SARS-CoV-2 cell entry by down-regulating SKP2 dependent ACE2 degradation

Coronavirus disease 2019 (COVID-19) outbreak has become a global pandemic. CDK4/6 inhibitor palbociclib was reported to be one of the top-scored repurposed drugs to treat COVID-19. As the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry, expression level of angiotensin-converting enzyme 2 (ACE2) is closely related to SARS-CoV-2 infection. In this study, we demonstrated that palbociclib and other methods could arrest cells in G0/G1 phase and up-regulate ACE2 mRNA and protein levels without altering its subcellular localization. Palbociclib inhibited ubiquitin-proteasome and lysosomal degradation of ACE2 through down-regulating S-phase kinase-associated protein 2 (SKP2). In addition, increased ACE2 expression induced by palbociclib and other cell cycle arresting compounds facilitated pseudotyped SARS-CoV-2 infection. This study suggested that ACE2 expression was down-regulated in proliferating cells. Cell cycle arresting compounds could increase ACE2 expression and facilitate SARS-CoV-2 cell entry, which may not be suitable therapeutic agents for the treatment of SARS-CoV-2 infection.

Targeting ACE2-BRD4 crosstalk in colorectal cancer and the deregulation of DNA repair and apoptosis

ACE2 overexpression in colorectal cancer patients might increase susceptibility to SARS-CoV-2 infection. We report that knockdown, forced overexpression, and pharmacologic inhibition in human colon cancer cells targeted ACE2-BRD4 crosstalk to mediate marked changes in DNA damage/repair and apoptosis. In colorectal cancer patients for whom high ACE2 plus high BRD4 expression is predictive of poor survival, pan-BET inhibition would need to consider proviral/antiviral actions of different BET proteins during SARS-CoV-2 infection.

Blood ACE Phenotyping for Personalized Medicine: Revelation of Patients with Conformationally Altered ACE.

Background: The angiotensin-converting enzyme (ACE) metabolizes a number of important peptides participating in blood pressure regulation and vascular remodeling. Elevated blood ACE is a marker for granulomatous diseases and elevated ACE expression in tissues is associated with increased risk of cardiovascular diseases. Objective and Methodology: We applied a novel approach -ACE phenotyping-to find a reason for conformationally impaired ACE in the blood of one particular donor. Similar conformationally altered ACEs were detected previously in 2-4% of the healthy population and in up to 20% of patients with uremia, and were characterized by significant increase in the rate of angiotensin I hydrolysis. Principal findings: This donor has (1) significantly increased level of endogenous ACE inhibitor in plasma with MW less than 1000; (2) increased activity toward angiotensin I; (3) M71V mutation in ABCG2 (membrane transporter for more than 200 compounds, including bilirubin). We hypothesize that this patient may also have the decreased level of free bilirubin in plasma, which normally binds to the N domain of ACE. Analysis of the local conformation of ACE in plasma of patients with Gilbert and Crigler-Najjar syndromes allowed us to speculate that binding of mAbs 1G12 and 6A12 to plasma ACE could be a natural sensor for estimation of free bilirubin level in plasma. Totally, 235 human plasma/sera samples were screened for conformational changes in soluble ACE. Conclusions/Significance: ACE phenotyping of plasma samples allows us to identify individuals with conformationally altered ACE. This type of screening has clinical significance because this conformationally altered ACE could not only result in the enhancement of the level of angiotensin II but could also serve as an indicator of free bilirubin levels.

Pathogenesis of Chronic Kidney Disease Is Closely Bound up with Alzheimer’s Disease, Especially via the Renin-Angiotensin System

Chronic kidney disease (CKD) is a clinical syndrome secondary to the definitive change in function and structure of the kidney, which is characterized by its irreversibility and slow and progressive evolution. Alzheimer's disease (AD) is characterized by the extracellular accumulation of misfolded β-amyloid (Aβ) proteins into senile plaques and the formation of neurofibrillary tangles (NFTs) containing hyperphosphorylated tau. In the aging population, CKD and AD are growing problems. CKD patients are prone to cognitive decline and AD. However, the connection between CKD and AD is still unclear. In this review, we take the lead in showing that the development of the pathophysiology of CKD may also cause or exacerbate AD, especially the renin-angiotensin system (RAS). In vivo studies had already shown that the increased expression of angiotensin-converting enzyme (ACE) produces a positive effect in aggravating AD, but ACE inhibitors (ACEIs) have protective effects against AD. Among the possible association of risk factors in CKD and AD, we mainly discuss the RAS in the systemic circulation and the brain.

Suppression of angiotensin converting enzyme 2, a host receptor for SARS-CoV-2 infection, using 5-aminolevulinic acid in vitro.

Angiotensin converting enzyme 2 (ACE2), an entry receptor found on the surface of host cells, is believed to be detrimental to the infectious capability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Scientists have been working on finding a cure since its outbreak with limited success. In this study, we evaluated the potential of 5-aminolevulinic acid hydrochloride (ALA) in suppressing ACE2 expression of host cells. ACE2 expression and the production of intracellular porphyrins following ALA administration were carried out. We observed the reduction of ACE2 expression and intracellular porphyrins following ALA administration. ALA suppressed the ACE2 expression in host cells which might prevent binding of SARS-CoV-2 to host cells. Co-administration of ALA and sodium ferrous citrate (SFC) resulted in a further decrease in ACE2 expression and increase in intracellular heme level. This suggests that the suppression of ACE2 expression by ALA might occur through heme production. We found that the inhibition of heme oxygenase-1 (HO-1), which is involved in heme degradation, also resulted in decrease in ACE2 expression, suggesting a potential role of HO-1 in suppressing ACE2 as well. In conclusion, we speculate that ALA, together with SFC administration, might serve as a potential therapeutic approach in reducing SARS-CoV-2 infectivity through suppression of ACE2 expression.

SARS-CoV-2 Spike Protein Activates Human Lung Macrophages.

COVID-19 is a viral disease caused by SARS-CoV-2. This disease is characterized primarily, but not exclusively, by respiratory tract inflammation. SARS-CoV-2 infection relies on the binding of spike protein to ACE2 on the host cells. The virus uses the protease TMPRSS2 as an entry activator. Human lung macrophages (HLMs) are the most abundant immune cells in the lung and fulfill a variety of specialized functions mediated by the production of cytokines and chemokines. The aim of this project was to investigate the effects of spike protein on HLM activation and the expression of ACE2 and TMPRSS2 in HLMs. Spike protein induced CXCL8, IL-6, TNF-α, and IL-1β release from HLMs; promoted efficient phagocytosis; and induced dysfunction of intracellular Ca2+ concentration by increasing lysosomal Ca2+ content in HLMs. Microscopy experiments revealed that HLM tracking was affected by spike protein activation. Finally, HLMs constitutively expressed mRNAs for ACE2 and TMPRSS2. In conclusion, during SARS-CoV-2 infection, macrophages seem to play a key role in lung injury, resulting in immunological dysfunction and respiratory disease.

Abstract 111: Cerebrovascular Effects Of Pre/post-losartan Treatment In Humanized ACE2 Knock-in Mice After SARS-CoV-2 Spike Protein Injection

SARS-CoV-2 has killed millions of people globally and has left many with devastating health problems, including neurological deficits. SARS-CoV-2 invades endothelial cells via binding its Spike-protein with angiotensin-converting enzyme 2 (ACE2) receptors. Losartan, an angiotensin receptor blocker, upregulates ACE2 expression. We hypothesize that pre-treatment with losartan could increase the cerebrovascular dysfunction associated with SARS-CoV-2 spike-protein, while post-SARS-CoV-2 losartan would provide potential protective effects. Methods: Recombinant SARS-CoV-2 spike-protein was injected intravenously in transgenic hACE2 mice, humanized ACE2 receptors knock-in mice. Treatment with losartan was started either two weeks before or right after spike-protein injection. Cognitive function was assessed using Y-Maze. Vascular density and cerebral blood flow were evaluated in the hACE2 mice with/out spike protein injection. Western blot and RT-PCR analysis were used to measure protein/gene expression. Results: Spike-protein injection decreased cerebral vascular density and cerebral blood flow in hACE2 brains compared to control (*P<0.05), which was associated with increased cognitive dysfunction in h ACE2 mice (*P<0.05). Pre-losartan treatment exacerbated spike protein-induced cognitive dysfunction, while post-losartan treatment helped restore cognitive function (*P<0.05). Spike-protein decreased ACE2 expression and increased endothelial cell inflammation and apoptosis, as shown by the increased expression of TNF- α ; and caspase-3 (*P<0.05), which were prevented by post-losartan treatment. Conclusion: Spike-protein decreased vascular density, cerebral blood flow, and cognitive function via increasing brain endothelial cell apoptosis. Pre-losartan treatment exacerbated the detrimental effects of spike-protein, while post-losartan treatment restored ACE2 expression and decreased SARS-CoV-2 spike-protein damaging effects.

Cytometry and analytical methods in COVID‐19 diagnostics and potential treatment: A special issue on Cytometry Part A

Cytometry and analytical methods in <scp>COVID</scp>‐19 diagnostics and potential treatment: A special issue on Cytometry Part A

COVID-19: Understanding the impact of anti-hypertensive drugs and hydroxychloroquine on the ACE1 and ACE2 in lung and adipose tissue in SHR and WKY rats.

Hypertensive individuals taking anti-hypertensive drugs from renin-angiotensin system inhibitors may exhibit a more severe evolution of the disease when contracting the SARS-CoV-2 virus (COVID-19 disease) due to potential increases in ACE2 expression. The study investigated ACE1 and ACE2 axes and hydroxychloroquine in the lungs and adipose tissue of male and female normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHRs). SHRs were treated with losartan (10mg/kg/day) or captopril (10mg/kg/day) for 14 days or 7 days with hydroxychloroquine (200 mg/kg/day) in drinking water. WKY rats were also treated for 7 days with hydroxychloroquine. Blood pressure (BP), protein, and mRNA expression of ACE1 and ACE2 were analyzed in serum, adipose, and lung tissues. Losartan and captopril reduced BP in both sexes in SHR, whereas hydroxychloroquine increased BP in WKY rats. Losartan reduced ACE2 in serum and lungs in both sexes and in adipose tissue of male SHRs. Captopril decreased ACE2 protein in the lung of females and in adipose tissue in both sexes of SHRs. Hydroxychloroquine decreased ACE1 and ACE2 proteins in the lungs in both sexes and adipose tissue in male SHRs. In female WKY rats, ACE2 protein was lower only in the lungs and adipose tissue. Losartan effectively inhibited ACE2 in male and captopril in female SHRs. Hydroxychloroquine inhibited ACE2 in male SHRs and female WKY rats. These results further our understanding of the ACE2 mechanism in patients under renin-angiotensin anti-hypertensive therapy and in many trials using hydroxychloroquine for COVID-19 treatment and potential sex differences in response to drug treatment.

Abstract 110: Why Diabetics Are More Vulnerable To Cerebrovascular Complications Of SARS-CoV-2? An In-vivo Animal Study

Diabetics are more vulnerable to SARS-CoV-2 cerebrovascular complications, including brain fog, cognitive impairment, and strokes. This study aims to identify the molecular mechanisms of SARS-CoV-2-induced cerebrovascular dysfunction in diabetes. We hypothesize that SARS-CoV-2 exacerbates diabetes-induced cerebral oxidative stress and inflammation via activation of the destructive arm of the renin-angiotensin system (RAAS) and Toll-Like receptor (TLR) signaling. Methods: SARS-CoV-2 spike-protein binds to human angiotensin-converting enzyme-2 (ACE2) receptors but not murine Ace2. Therefore, type-2 diabetes was induced in humanized ACE2 (hACE2) knock-in transgenic mice using low-dose streptozotocin followed by eight weeks of a high-fat diet. Recombinant SARS-CoV-2 spike-protein was injected intravenously in control and diabetic mice. Cognitive functions were tested using Y-maze and Barnes maze. RAAS system and TLR signaling were assessed using RT-PCR and western blot analysis. The cerebrovascular architecture was measured using immunohistochemistry. Results: Diabetes increased cerebrovascular oxidative stress markers NOX1 and NOX5 and inflammatory markers Il-6, Il-1β, and TNF-α gene expression (P&lt;0.05). Diabetes upregulated angiotensin II and angiotensin 1 receptor (AT1R) expression, these effects were amplified by spike-protein (P&lt;0.05). Moreover, spike-protein injection decreased RAAS protective arm, ACE2, and AT2R expression (P&lt;0.05). In parallel, spike-protein exacerbated TLR signaling in diabetes. Spike-protein increased the TLR-8 receptors and its ligands HMGB1 and S100 and downstream adaptor proteins MyD88, TRAF6, and NF-κB expression (P&lt;0.05). Spike-protein significantly increased cerebrovascular rarefaction and cognitive dysfunction in diabetes (P&lt;0.05). Conclusion: SAR-CoV-2 spike-protein intensified RAAS and TLR signaling in diabetes leading to additional cerebrovascular damage and cognitive dysfunction. Targeting RAAS and TLR singling are possible therapeutic strategies to protect against SAR-CoV-2-induced cerebrovascular dysfunction in diabetes.

Topical captopril: a promising treatment for secondary lymphedema

Transforming growth factor-beta 1 (TGF-β1)-mediated tissue fibrosis is an important regulator of lymphatic dysfunction in secondary lymphedema. However, TGF-β1 targeting can cause toxicity and autoimmune complications, limiting clinical utility. Angiotensin II (Ang II) modulates intracellular TGF-β1 signaling, and inhibition of Ang II production using angiotensin-converting enzyme (ACE) inhibitors, such as captopril, has antifibrotic efficacy in some pathological settings. Therefore, we analyzed the expression of ACE and Ang II in clinical lymphedema biopsy specimens from patients with unilateral breast cancer-related lymphedema (BCRL) and mouse models, and found that cutaneous ACE expression is increased in lymphedematous tissues. Furthermore, topical captopril decreases fibrosis, activation of intracellular TGF-β1 signaling pathways, inflammation, and swelling in mouse models of lymphedema. Captopril treatment also improves lymphatic function and immune cell trafficking by increasing collecting lymphatic pumping. Our results show that the renin-angiotensin system in the skin plays an important role in the regulation of fibrosis in lymphedema, and inhibition of this signaling pathway may hold merit for treating lymphedema.

The Association of Angiotensin-Converting Enzyme 2 Polymorphism and SARS-CoV-2 Infection in the Iraqi Population.

The quick and advancing prevalence of the new coronavirus SARS-CoV-2 produced a global crisis surge with a profound impact on human health and worldwide economic constancy. The virus is known as one strain of coronavirus, which causes the respiratory infection responsible for the current pandemic of COVID-19. The virus spike protein has a high binding affinity to human ACE2, depending on crystallization analysis and biochemical interaction studies. Studies consistently reveal that rs2285666, a polymorphism found in ACE2, diverse significantly between Europeans and Asians, changing ACE2 expression. The alternating allele TT of rs2285666 SNP increased gene expression to 50%; thus, it may have a role in SARS-COV-2 infection vulnerability. This study aimed to investigate rs2285666 SNP association with SARS-CoV2 infection as a first report in the Iraqi population. Fifty (20 Male/30 Female) Covid-19 patients with severe symptoms with mean age (of 41.5±10.7) and 50 (20 Male/30 Female) healthy people as a control group with mean age (of 41.5±10.7) were included in this study. Sample of a patient tested as a mutant genotype (TT) by RFLP assay. The results reveal a MAF value of 0.3 for this gene in Iraqi samples, more than Europeans (0.2) and less than East Asians (0.55). The codominant model had significant OR of both alleles CT and TT (OR=4.26 & 6.7; P-value=0.012 & 0.023 respectively). In conclusion, there is an association between increased severity of SARS-Cov-2 infection and rs2285666 polymorphism of the codominant genotype model of the Iraqi population. However, several other factors may affect disease severity, such as ethnic group differences, sex, comorbidity, virus strain, and others.

P895 Differences in ulcerative colitis patients regarding COVID-19 status

Abstract Background Severe acute respiratory syndrome coronavirus 2 is the novel coronavirus that caused the coronavirus disease 2019 (COVID-19) outbreak. Studies have increasingly reported the involvement of other organs, including the gastrointestinal system, in addition to the respiratory system. Ulcerative colitis is an inflammatory bowel disease with an unknown cause. Emerging data suggest that the gastrointestinal system may be influenced by COVID-19 via the expression of angiotensin-converting enzyme-2, but data on the association between COVID-19 and ulcerative colitis, are lacking. Methods In 6-month time (June to December 2021) 49 ulcerative colitis (UC) outpatients from Riga East Clinical University Hospital were included in a cross-sectional study. All patients were divided into groups according to medically proven COVID-19 status (COVID-19+ vs COVID-19-) in the last 6 months. Information about diet, IBD medications, food supplements, vitamins, sports activities, marital status, education level, and income level was collected. Data were analyzed with SPSS 20.0. Results Out of 49 patients, 33(63.3%) were males and 13(36.7%) were females, median age was 38.0 [IQR=17] years. Fourteen patients (28.6%: 7(50%) in each gender) were Covid-19+ within last 6 months. Median time patients suffered from COVID-19 was 7 [IQR=15.3] days. The most common symptoms were: 11(19.6%) fever, 6(10.7%) rhinitis and 5(8.9%) weakness. The most common diet among all patients was IBD diet 33(67.3%) from those 12(21.4%) were COVID-19- and 4(78.6%) were COVID-19+, p=0.00. Out of 49 patients, 25(44.6%) were using food supplements (fish oil, curcumin, collagen, zinc, calcium) of those 17(30.4%) patients were COVID-19-, 8(14.3%) COVID-19+, p=0.00. Most commonly used vitamins were vitamin D 18(64,3%), from those 15(42.9%) were COVID-19-, 3(21.4%) COVID-19+, p&amp;gt;0.5; vitamin C – 7(32,8%), from those 4(11.4%) were COVID-19-, 3(21.4%) COVID-19+, p&amp;gt;0.5. Twenty-four (49%) were doing sports, of those 18(51.4%) were COVID-19-, 6 (42.9%) COVID+; p&amp;gt;0.5. Most common sports activities were cycling 8(16.3%), running 8(16.3%) and fitness 6(12.2%). Most commonly used IBD medications were mesalazine 35(71.4%), azathioprine 7(14.3%) and biologics 4(8.16%), there were no statistically significant differences between COVID-19+ and COVID-19-. There were no statistically significant differences between marital status, education level, and income regarding COVID-19 status. Conclusion COVID-19 was less common among patients who were using food supplements and followed IBD diet.

Perindopril Reduce SARS-COV-2 Spike-ACE2 Binding, ACE2 Overexpression and Cytokine Storm in Adipocyte Cell Infected with SARS-COV-2

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Ristekdikti Background and Aims The SARS-CoV-2 virus can infect adipocyte cells via ACE2 Receptor thus triggering ACE2 overexpression and cytokine storms which cause lethal complications. Hence, we explore the effect of Perindopril on the expression of ACE2, IL-6, IL-1B TNF-α in adipocyte cultures infected by SARS-CoV-2 spike protein and identify the possible mechanism involved. Materials and Methods Adipocyte culture obtained from a healthy and obese donor was divided into 4 triplicate groups (P0: negative control without treatment; P1: positive control (SARS-CoV-2 spike protein); P2: SARS-CoV-2 spike protein + exposure to Perindopril 0.5 µM); P3: SARS-CoV-2 spike protein + anti-ACE2 antibody 100 µg/mL; and evaluated at 24 and 48 hours. ACE2 expression was evaluated using immunofluorescence. IL-6, TNFα, and IL-1B were evaluated using ELISA. SARS-COV-2 Spike-ACE2 Binding was evaluated using Competitive ELISA. Data analysis was performed using SPSS 25.0 software. Results At first 24 hours of incubation, perindopril treatment has the highest ACE2 expression compared to negative control, positive control and anti-ACE2 antibody (113.52±0.34 ng/mL vs 13.3±0.87 ng/mL, 90.2±2.73 ng/mL, 17.3±0.11 ng/mL, p&amp;lt;0.01), lower ACE-ACE2R binding compared to anti-ACE2 antibody group (169.52±4.07 ng/mL vs 290.71±6.22 ng/mL, p&amp;lt;0.01) and higher IL-6 expression compared to positive control group (64.65±0.12 ng/mL vs 60.08±0.77 ng/mL p&amp;lt;0.01). Interestingly, after 48 hours, perindopril treatment was shown to prevent further increase of ACE2 expression compared to a positive control (47.37±0.76 ng/mL vs 80.31±5.37 ng/mL, p&amp;lt;0.01), higher SARS-COV-2 Spike-ACE2 binding compared to anti-ACE2 antibody group (143.68±3.68 ng/mL vs 103.1±9.49 ng/mL, p&amp;lt;0.01), and lower IL-6 expression compared to the positive control group (42.66±1.94 ng/mL vs 90.93±2.48 ng/mL p&amp;lt;0.01). However, no significant difference in TNFα and IL-1B expression between perindopril treatment and positive control in both 24 and 48 hours. Conclusion This study showed that perindopril reduces cytokine storm by preventing ACE-2 and IL-6 overexpression via an increasing number of SARS-COV-2 Spike-ACE2 competitive binding in adipocyte culture infected with SARS-COV-2 spike protein. A further clinical trial is needed to prove the benefit of perindopril in obese patients with COVID-19.

Formaldehyde causes an increase in blood pressure by activating ACE/AT1R axis

Previous studies suggest some link between formaldehyde exposure and harmful cardiovascular effects. But whether exposure to formaldehyde can cause blood pressure to rise, and if so, what the underlying mechanism is, remains unclear. In this study, C57BL/6 male mice were exposed to 0.1, 0.5, 2.5 mg/m3 of gaseous formaldehyde for 4 h daily over a three-week period. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) of the mice were measured by tail-cuff plethysmography, and any histopathological changes in the target organs of hypertension were investigated. The results showed that exposure to formaldehyde did cause a significant increase in blood pressure and heart rate, and resulted in varying degrees of damage to the heart, aortic vessels and kidneys. To explore the underlying mechanism, a specific inhibitor of angiotensin converting enzyme (ACE) was used to block the ACE/AT1R axis. We observed the levels of ACE and angiotensin II type 1 receptor (AT1R), as well as the bradykinin (BK) in cardiac cytoplasm. The data suggest that exposure to formaldehyde induced an increase in the expression of ACE and AT1R, and decreased the levels of BK. Strikingly, treatment with 5 mg/kg/d ACE inhibitor can attenuate the increase in blood pressure and the pathological changes caused by formaldehyde exposure. This result has improved our understanding of whether, and how, formaldehyde exposure affects the development of hypertension.