ABSTRACT
According to the World Health Organization, Tuberculosis (TB) is the second leading cause of death by a single infectious disease behind COVID-19. Despite a century of effort, the current TB vaccine does not effectively prevent pulmonary TB, promote herd immunity, or prevent transmission. Therefore, we seek to develop a genetic prophylaxis for TB. We have determined D-cycloserine to be the optimal target for this approach due to its relatively short six-enzyme biosynthetic pathway. D-CS is a second-line antibiotic for TB that inhibits bacterial cell wall synthesis. The first committed step towards D-CS synthesis is catalyzed by the L-serine-O-acetyltransferase (DcsE) which converts L-serine and acetyl-CoA to O-acetyl-L-serine (L-OAS). To test if the D-CS pathway could be an effective prophylaxis for TB in human cells, we endeavored to express DcsE in human cells and test its functionality. We overexpressed DcsE tagged with FLAG and GFP in A549 lung cancer cells as determined using fluorescence microscopy. We observed that purified DcsE catalyzed the synthesis of L-OAS as observed by HPLC-MS. Therefore, DcsE synthesized in human cells is a functional enzyme capable of converting L-serine and acetyl-CoA to L-OAS demonstrating the first step towards DCS production in human cells.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.
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Background/Objectives: SARS-CoV2 causes the COVID-19 disease, capable of producing a severe acute respiratory syndrome. Several clinical variables and genetic variants have been related to a worse prognosis. The aim of this study is to measure if difference in the gene expression are associated with COVID-19 severity. Method(s): We performed RNA-seq Transcriptome in RNA extracted from lymphoblastoid cell line in 20 patients who require hospitalization (10 from the intensive care unit) in a GeneStudio S5 Plus Sequencer (Ion Torrent Technology). FASTQ files were obtained and trimmed using BBtools, BBduk for cutting, filtering and masking the data, and Dedupe for the elimination of duplicates. Mapping and counting matrix was done in bash using the Salmon program. Differential expression analysis and subsequent functional enrichment was performed using Rstudio (DESeq2, ClusterProfiler, GO and KEGG). Result(s): We observed that 2042 differentially expressed genes (1996 overexpressed, LFC>0 and 406 underexpressed, LFC<0) were obtained between patients who require hospitalization versus those in the intensive care unit. We found some genes previously SARS-CoV-2 associated (PGLYRP1, HDAC9 and FUT4). Furthermore, genes involved in the activity of the immune system and in inflammatory processes showed significant differences between cohorts (ABCF1 (LFC = -25.14, padj = 1.05e-13), ABHD16A (LFC = 25.00, padj = 1.05e-13) and IER3 (LFC = -24.45, padj = 2.43e-13)). Conclusion(s): We described differential expression in genes of the immune system and inflammatory processes that might be have a role in the risk of develop severe symptoms of COVID-19, including admission in the intensive care unit. This results should be validated by additional functional studies.
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Background: COVID-19 causes significant morbidity and mortality, albeit with considerable heterogeneity among affected individuals. It remains unclear which host factors determine disease severity and survival. Given the propensity of clonal hematopoiesis (CH) to promote inflammation in healthy individuals, we investigated its effect on COVID-19 outcomes. Method(s): We performed a multi-omics interrogation of the genome, epigenome, transcriptome, and proteome of peripheral blood mononuclear cells from COVID-19 patients (n=227). We obtained clinical data, laboratory studies, and survival outcomes. We determined CH status and TET2-related DNA methylation. We performed single-cell proteogenomics to understand clonal composition in relation to cell phenotype. We interrogated single-cell gene expression in isolation and in conjunction with DNA accessibility. We integrated these multi-omics data to understand the effect of CH on clonal composition, gene expression, methylation of cis-regulatory elements, and lineage commitment in COVID-19 patients. We performed shRNA knockdowns to validate the effect of one candidate transcription factor in myeloid cell lines. Result(s): The presence of CH was strongly associated with COVID-19 severity and all-cause mortality, independent of age (HR 3.48, 95% CI 1.45-8.36, p=0.005). Differential methylation of promoters and enhancers was prevalent in TET2-mutant, but not DNMT3A-mutant CH. TET2- mutant CH was associated with enhanced classical/intermediate monocytosis and single-cell proteogenomics confirmed an enrichment of TET2 mutations in these cell types. We identified celltype specific gene expression changes associated with TET2 mutations in 102,072 single cells (n=34). Single-cell RNA-seq confirmed the skewing of hematopoiesis towards classical and intermediate monocytes and demonstrated the downregulation of EGR1 (a transcription factor important for monocyte differentiation) along with up-regulation of the lncRNA MALAT1 in monocytes. Combined scRNA-/scATAC-seq in 43,160 single cells (n=18) confirmed the skewing of hematopoiesis and up-regulation of MALAT1 in monocytes along with decreased accessibility of EGR1 motifs in known cis-regulatory elements. Using myeloid cell lines for functional validation, shRNA knockdowns of EGR1 confirmed the up-regulation of MALAT1 (in comparison to wildtype controls). Conclusion(s): CH is an independent prognostic factor in COVID-19 and skews hematopoiesis towards monocytosis. TET2-mutant CH is characterized by differential methylation and accessibility of enhancers binding myeloid transcriptions factors including EGR1. The ensuing loss of EGR1 expression in monocytes causes MALAT1 overexpression, a factor known to promote monocyte differentiation and inflammation. These data provide a mechanistic insight to the adverse prognostic impact of CH in COVID-19.
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Background: Aging and binge alcohol abuse are both known as independent risk factors for both atrial and ventricular arrhythmias. With the COVID-19 pandemic, increased social isolation has significantly increased alcohol consumption worldwide. Older adults are a high-risk drinking group and alcohol significantly enhances the risk of arrhythmia onset. Yet, how alcohol (a secondary stressor) drives spontaneous atrial and ventricular arrhythmia onset in the aged heart (a primary stressor) remains unclear. Objective(s): We recently reported the stress-response kinase c-jun N-terminal kinase 2 (JNK2) underlies alcohol-enhanced atrial arrhythmia vulnerability (pacing-induced) in healthy young hearts. Here, we reveal a critical role of JNK2 in alcohol-driven arrhythmia onset in the aged heart in vivo. Method(s): Ambulatory ECGs were recorded using wireless telemeters in binge alcohol-exposed aged (24 months) and young mice (2 months). Spontaneous premature atrial and ventricular contractions (PACs, PVCs), atrial and ventricular tachycardia (AT, VT) were quantified as previously described. The role of JNK2 in triggered arrhythmic activities was assessed using a well-evaluated JNK2-specific inhibitor and our unique cardiac-specific MKK7D and MKK7D-JNK2dn mouse models with tamoxifen inducible overexpression of constitutively active MKK7 (a JNK upstream activator) or co-expression of MKK7D and inactive dominant negative JNK2 (JNK2dn). Result(s): We found that binge alcohol exposure in aged mice (n=14) led to spontaneous PACs/PVCs (75% of the mice), and AT/VT episodes (50%) along with a 21% mortality rate. However, alcohol-exposed young (n=5) and non-alcohol-exposed aged mice (n=11) were absent of any spontaneous arrhythmic activities or premature death. Intriguingly, JNK2-specific inhibition in vivo abolished those alcohol-associated triggered activities and mortality in aged mice. The causative role of JNK2 in triggered arrhythmias and premature death was further supported by the high frequency of spontaneous PACs/PVCs and nonsustained AT/VT episodes along with a 50% mortality rate in MKK7D mice (n=10), which was strikingly alleviated in MKK7D-JNK2dn mice (n=5) with cardiac-specific JNK2 competitive inhibition. Conclusion(s): Our findings are the first to reveal that stress kinase JNK2 underlies binge alcohol-evoked atrial and ventricular arrhythmia initiation in aged mice. Modulating JNK2 could be a novel therapeutic strategy to treat and/or prevent binge drinking-evoked cardiac arrhythmias.Copyright © 2023
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Coronavirus-induced disease-19 (COVID-19), caused by SARS-CoV-2, is still a major global health challenge. Human endogenous retroviruses (HERVs) represent retroviral elements that were integrated into the ancestral human genome. HERVs are important in embryonic development as well as in the manifestation of diseases, including cancer, inflammation, and viral infections. Here, we analyze the expression of several HERVs in SARS-CoV-2-infected cells and observe increased activity of HERV-E, HERV-V, HERV-FRD, HERV-MER34, HERV-W, and HERV-K-HML2. In contrast, the HERV-R envelope is downregulated in cell-based models and PBMCs of COVID-19 patients. Overexpression of HERV-R inhibits SARS-CoV-2 replication, suggesting its antiviral activity. Further analyses demonstrate the role of the extracellular signal-regulated kinase (ERK) in regulating HERV-R antiviral activity. Lastly, our data indicate that the crosstalk between ERK and p38 MAPK controls the synthesis of the HERV-R envelope protein, which in turn modulates SARS-CoV-2 replication. These findings suggest the role of the HERV-R envelope as a prosurvival host factor against SARS-CoV-2 and illustrate a possible advantage of integration and evolutionary maintenance of retroviral elements in the human genome.Copyright © 2023 The Authors.
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Background: We previously screened 10 human lung and upper airway cell lines expressing variable levels of endogenous ACE2/TMPRSS2. We found that H522 human lung adenocarcinoma cells supported SARS-CoV-2 replication independent of ACE2, whereas the ACE2 positive cell lines were not permissive to infection. Type I/III interferons (IFNs) potently restrict SARS-CoV-2 replication through the actions of hundreds of interferon-stimulated genes (ISGs) that are upregulated upon IFN signaling. Here we report that a number of ACE2 positive airway cell lines are unable to support SARS-CoV-2 replication due to basal activation of the cGAS-STING DNA sensing pathway and subsequent upregulation of IFNs and ISGs which restrict SARS-CoV-2 replication. Method(s): SARS-CoV-2 WT strain 2019-nCoV/USA-WA1/2020 viral replication was detected through analysis of cell associated RNA. RNA sequencing was used to study the basal level of genes in the type-I IFN pathway in the 10 cell lines, which was further validated by western blotting and qRT-PCR. A panel of 5 cell lines, with varying expression levels of ACE2 and TMPRSS2, were pre-treated with Ruxolitinib, a JAK1/2 inhibitor. A siRNA-mediated screen was used to determine the molecular basis of basally high expression of ISGs in cell lines. CRISPR knockout of IFN-alpha receptor and cGAS-STING pathway components was conducted in parallel Results: Here we show that higher basal levels of IFN pathway activity underlie the inability of ACE2+ cell lines to support virus replication. Importantly, this IFN-induced block can be overcome by chemical inhibition and genetic disruption of the IFN signaling pathway or by ACE2 overexpression, suggesting that one or more saturable ISGs underlie the lack of permissivity of these cells. Ruxolitinib treatment increased SARS-CoV-2 RNA levels by nearly 3 logs in OE21 and SCC25. Furthermore, the baseline activation of the STING-cGAS pathway accounts for the high ISG levels and genetic disruption of the cGAS-STING pathway enhances levels by nearly 2 and 3 logs of virus replication in the two separate ACE2+ cell line models respectively. Conclusion(s): Our findings demonstrate that cGAS-STING-dependent activation of IFN-mediated innate immunity underlies the inability of ACE2+ airway cell lines to support SARS-CoV-2 replication. Our study highlights that in addition to ACE2, basal activation of cGAS-STING pathway, IFNs and ISGs may play a key role in defining SARS-CoV-2 cellular tropism and may explain the complex SARS-CoV- 2 pathogenesis in vivo.
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Serum Amyloid A (SAA) is an apolipoprotein found in the serum of many vertebrate species and is associated with the acute-phase reaction in the body with expression levels reaching up to a 1000-fold increase. The loss of its alpha-helix conformation during its expression peak is directly linked to secondary amyloidosis. Recent studies have been suggested to play a role in cholesterol and HDL metabolism, retinol transport and tumor pathogenesis. Moreover, high SAA concentration in blood have been correlated with severe symptoms or death in patients with COVID-19. However, how this protein is involved in so many diseases is uncertain or not completely understood. Therefore, the purpose of this research is to determine which protein-protein interactions with SAA occur in human cells, and to predict its biochemical role based on new discovered complexes. Two major isoforms overexpressed during an acutephase reaction, human SAA1 and SAA2, are the focus of this study. Both are primarily produced in hepatocytes. HepG2 cells were cultured and induced with interleukin-1b, interleukin-6, LPS and retinol. Protein complexes associated with SAA will be isolated through a co-Immunoprecipitation technique, resolved by SDS-PAGE, and characterized by mass spectrometry. Our hypothesis focus on those protein complexes with SAA to explain how this protein lead other undiscovered metabolic pathways involved in both cellular and survival regulation. Special thanks to The Science and Technology Competency & Education Core (Stce) for Undergraduate and Graduate Junior Research Associates Working Program from the Puerto Rico IDeA Network Biomedical Research Excellence for funding part of this research.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.
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Background: Severe COVID-19 is less common in children than in adults. Increasing evidence show that distinct immune-pathological changes can persist weeks or months after SARS-CoV2 infection, leading to Long COVID (LC). We investigated the systemic type I/III interferon (IFN-I/III) and inflammation response in peripheral blood mononuclear cells (PBMCs) of children with and without LC symptoms. Method(s): Blood samples were collected from children attending Umberto I hospital of Rome, within 3-6 months after a SARS-CoV-2 positive test and from control children. RNA was extracted from PBMCs for determining the levels of IFN-I (IFN-Alpha2, -Beta, -Epsilon and -Omega), IFN-III (IFN-Lambda1-3), NLRP3 and IL-1beta genes, and miR-141 expression by quantitative RealTime-PCR assays, normalized to housekeeping GUS gene and RNU6B, respectively. Result(s): 28 participants (M 12.5y SD 3.0) with LC symptoms, 28 participants (M 11.8y SD 3.0) without LC symptoms and 18 children who've never had SARS-CoV- 2 infection (M 10.5y SD 3.1) were enrolled. Comparing the three study groups, we found reduced levels of IFN-Lambda1, IFN-Lambda2 and IFN-Lambda3 (p=0.006, p< 0.001, p=0.012, respectively;Kruskal-Wallis (KW) test) mRNA in patients who have had SARS-CoV-2 infection as opposed to control group, whereas transcript levels of IFN-Epsilon (p= 0.019;KW test) were increased in the former with respect to the latter group;as well, remaining IFN-I genes analyzed showed a tendency to be up-regulated. As far as NLRP3 and IL-1beta levels was concerned, these genes were increased in LC patients (p< 0.001 for both genes;KW test). Additionally, miR-141, which has been reported to regulate inflammasome response, was overexpressed in LC patients (p< 0.001;Mann-Whitney test). Conclusion(s): These results showed a decreased levels of IFN-III mRNAs and an overexpression of IFN-Epsilon in children after 3-6 months of SARS-CoV-2 infection regardless of development of LC symptoms, suggesting that SARSCoV- 2 could have caused dysregulation of IFN response through unknown mechanisms (e.g. epigenetic modifications). Also, we found an overexpression of miR-141, NLRP3 and IL-1beta mRNAs in LC patients, indicating that a prolonged activation of inflammasome pathways could be associated with the development of LC symptoms.
ABSTRACT
SARS-CoV-2, the coronavirus that causes the disease COVID- 19, was identified over three years ago, yet current small molecule therapies have limited usefulness and resistance to therapies and vaccines is inevitable. Ultra high-throughput screening (uHTS) assays for novel and repurposed inhibitors of a protein-protein interaction in the viral life cycle could be used to screen a vast number of compounds with a specific target of action. In particular, the interaction between viral SPIKE protein and human TMPRSS2 is an understudied, yet critical step in viral entry. Thus, we aim to create uHTS assays to rapidly and affordably identify inhibitors of the TMPRSS2 and SPIKE interaction for further biochemical studies and therapeutic development for SARS-CoV-2.We first sought to create a Time Resolved-Forster/Fluorescence Energy Transfer (TR-FRET) assay which uses lysates of cells with overexpressed SPIKE and TMPRSS2 and fluorescently labeled antibodies to detect interactions between these proteins. Initially, we developed and optimized this TR-FRET assay in a 384-well plate then miniaturized to a 1536-well plate. We conducted a pilot screen of compounds with known biological activity to test this assay's screening capabilities. To further narrow the hits from this TR-FRET screen, we developed an orthogonal uHTS Nanoluciferase Binary Technology (NanoBiT) assay to detect the interaction between tagged SPIKE and TMPRSS2 in live cells.With these two assays in hand, we expanded our TR-FRET screen to over 100 000 compounds and identified several that were also positive in the orthogonal NanoBiT assay. Four of these compounds were found to potentially interact with either SPIKE or TMPRSS2 from thermal shift experiments, providing support for their action as SPIKE and TMPRSS2 interaction inhibitors. Thus, we have developed TR-FRET and NanoBiT orthogonal uHTS assays which have allowed for the discovery of several possible repurposed and novel inhibitors of the SPIKE/ TMPRSS2 interaction. These uHTS assays can be employed as a model for future drug discovery efforts and the compounds identified may be used as exciting starting points for development of inhibitors of SARS-CoV-2. This research was supported in part by The Emory School of Medicine COVID Catalyst-I3 award, the NCI Emory Lung Cancer SPORE (SR, HF;P50CA217691) Career Enhancement Program (AI, P50CA217691), Emory initiative on Biological Discovery through Chemical Innovation (AI) and R01AI167356 (SS).Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.
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Purpose of Study: Antibiotic resistance remains one of the largest healthcare and public health challenges. Several studies have documented that the spread of antibiotic resistant bacteria in nosocomial settings has been exacerbated worldwide due to increased rates of hospitalization and intubation in the wake of the COVID-19 pandemic. One way to address antibiotic resistance is to identify novel compounds that inhibit essential microbial processes. Two-component regulatory systems are important mediators of signal transduction that allow bacteria to communicate with and respond to changes in their environment. The WalRK system is a two-component system that is conserved and essential for viability in many Gram-positive human pathogens. We hypothesize that a ligand that specifically binds with the DNA-interaction surface of the WalR protein can lead to cell death and can serve as a lead compound for future drug development efforts. Methods Used: We describe the development process of an assay to identify WalR binding compounds. In silico molecular dynamics docking approaches were utilized to identify potential WalR binding compounds from virtual compound libraries. To assess their WalR-binding capacity in vitro, overexpression strains for several WalR recombinant constructs were engineered and protein constructs were purified to homogenicity. Isothermal titration calorimetry (ITC) is a technique that measures heat release or absorption when two molecules interact. A MicroCal PEAQ ITC instrument was utilized to develop a WalR-binding assay. Summary of Results: WalR is a two-domain protein featuring a regulatory and a DNA-binding domain. Two constructs, a truncated DNA-binding domain and a full-length protein construct proved soluble, and pure quantities necessary to conduct ITC measurements could be successfully obtained (12 mg full-length protein and 23 mg truncated protein). These proteins were amenable to ITC experiments. We found that experiments were best run with at least a two-fold increase of ligand concentration to protein concentration supplied in identical buffer conditions over nineteen injections. We are currently assessing the binding affinities of our in silico hit compounds. Conclusion(s): Our results show that ITC enables the detailed, rapid, and reproducible characterization of the binding relationship between the DNA-binding domain of the WalR protein and any potential ligands. The protocol discussed herein will enable further drug discovery studies on the WalR response regulator protein to identify and characterize inhibitors, providing insight towards the development of novel antimicrobial compound.
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Background: Obesity is a strong risk factor for more severe Covid-19 infection as adipocytes play an important role in intermediating the spreading, replication, and release of SARS-COV-2. An increase in pro-coagulation factors (tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1)) was observed in Covid-19 patients with moderate to severe symptoms and is reported to be associated with Angiotensin-converting enzyme 2 (ACE2) overexpression. Cardiovascular medications affecting ACE2, such as Perindopril and Losartan, are hypothesized to have an effect on Covid-19 infection-related coagulopathy. This study aims to identify and compare the effect of perindopril and losartan on TF and PAI-1 levels in adipocytes exposed to SARS-COV-2 spike protein. Method(s): Adipocytes were isolated enzymatically from adipose tissue obtained from an obese male donor. Adipocytes were then exposed to SARS-COV-2 S1 spike protein for 24 hours. After exposure, perindopril and losartan were added to the culture medium. ACE2, TF, and PAI-1expression were measured 2 hours later using ELISA. Result(s): SARS-CoV-2 spike protein exposure increased ACE2, TF, and PAI-1 expression. Perindopril addition discernible reduced the tissue factor (TF) expression (4.843 +/- 0.396) compared to a positive control (6.857 +/- 0.228) (p=0.005) but not losartan (5.624 +/- 0.606) (p=0.111). Perindopril was also able to lower PAI-1 expressions (3.484 +/- 0.252) compared to a positive control (4.865 +/- 0.115) (p=0.001), but the losartan did so more effectively (2.633 +/- 0.269) (p=0.000). Conclusion(s): Losartan and perindopril both have the ability to lower pro-coagulation factors, proving the value of ACEIs/ARBs in preventing thrombotic complications in Covid-19 patients.Copyright © 2023
ABSTRACT
COVID-19 has been found to affect the expression profile of several mRNAs and miRNAs, leading to dysregulation of a number of signaling pathways, particularly those related to inflammatory responses. In the current study, a systematic biology procedure was used for the analysis of high-throughput expression data from blood specimens of COVID-19 and healthy individuals. Differentially expressed miRNAs in blood specimens of COVID-19 vs. healthy specimens were then identified to construct and analyze miRNA-mRNA networks and predict key miRNAs and genes in inflammatory pathways. Our results showed that 171 miRNAs were expressed as outliers in box plot and located in the critical areas according to our statistical analysis. Among them, 8 miRNAs, namely miR-1275, miR-4429, miR-4489, miR-6721-5p, miR-5010-5p, miR-7110-5p, miR-6804-5p and miR-6881-3p were found to affect expression of key genes in NF-KB, JAK/STAT and MAPK signaling pathways implicated in COVID-19 pathogenesis. In addition, our results predicted that 25 genes involved in above-mentioned inflammatory pathways were targeted not only by these 8 miRNAs but also by other obtained miRNAs (163 miRNAs). The results of the current in silico study represent candidate targets for further studies in COVID-19.Copyright © 2023 Elsevier B.V.
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Background: It has been widely acknowledged that severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) infects host cells via the angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) entry mechanism. However, ACE2 and TMPRSS2 cannot explain the Toll-like receptor driven response of monocytes since there is no ACE2 expressed on monocytes, suggesting alternative receptor(s) on these cells. Here, we report cell surface glucose-regulated protein 78 (csGRP78) which is abundantly expressed on monocytes to function as an alternative receptor for SARS-CoV- 2 internalization. Method(s): Blood from COVID-19 patients and healthy donors were collected for csGRP78 and monocyte activation marker as well as cytokine concentration. In vitro SPR, GST pull-down and Co-IP assay were used to determine interaction between SARS-CoV- 2 spike protein and GRP78. Cytokine mixture of IL-1beta, IL-6, TNF and IFN-gamma were used to stimulated csGRP78 upregulation on human monocytic cell line THP-1. GRP78-overexpressing- THP- 1 was also established. pseudo-typed virus expressing spike protein was used to infect mock or GRP78 over-expressing THP-1 cells. Result(s): Our results show that csGRP78 is upregulated on the monocyte of COVID-19 patients. Moreover, in vitro cell culture experiments revealed that stimulation of wtTHP-1 and GRP78 over-expressing THP-1 with the relevant cytokines IL-1beta, IL-6, TNF and IFN-gamma induces similar csGRP78 and activation marker upregulation on cell surface as found on patients' monocytes. In vitro spike protein and GRP78 interaction tests, confirmed direct binding of spike protein and GRP78. Finally, pseudo-typed virus infection assay showed that virus entered GRP78 over-expressing THP-1 cells but not control THP-1 cells. Conclusion(s): Our results demonstrate that csGRP78 acts as a potential functional receptor for SARS-CoV- 2 spike protein and mediates ACE2 independent SARS-CoV- 2 entry into monocytes. These findings provide insight into role of monocytes in the pathophysiology of COVID-19, and suggest a new therapeutic target candidate for anti-SARS- CoV- 2 treatment.
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Still's disease in children (systemic juvenile idiopathic arthritis - JIA) and adult Still's disease (ASD) are considered as systemic autoinflammatory diseases of unknown etiology, which are based on similar immunopathogenetic mechanisms associated with genetically determined disorders of the mechanisms of innate immunity. ASD was first described 50 years ago by the English rheumatologist Eric George Lapthorne Bywaters. The molecular basis of ASD immunopathogenesis is the activation of innate immunity associated with NLRP3 inflammasome-dependent mechanisms of inflammation, characterized by the overproduction of "pro-inflammatory" cytokines - interleukin (IL) 1 and IL-18, inducing the synthesis of other proinflammatory inflammatory mediators. A review of new data concerning the mechanisms of immunopathology, clinical polymorphism, laboratory biomarkers and the possibilities of ASD pharmacotherapy is presented. Particular attention is paid to the prospects for the use of monoclonal antibodies to IL-1beta - canakinumab. The problems associated with the generality of clinical and laboratory disorders, pathogenetic mechanisms and pharmacotherapy of ASD and coronavirus disease 2019 (COVID-19) are considered.Copyright © 2021 Authors. All rights reserved.
ABSTRACT
Still's disease in children (systemic juvenile idiopathic arthritis - JIA) and adult Still's disease (ASD) are considered as systemic autoinflammatory diseases of unknown etiology, which are based on similar immunopathogenetic mechanisms associated with genetically determined disorders of the mechanisms of innate immunity. ASD was first described 50 years ago by the English rheumatologist Eric George Lapthorne Bywaters. The molecular basis of ASD immunopathogenesis is the activation of innate immunity associated with NLRP3 inflammasome-dependent mechanisms of inflammation, characterized by the overproduction of "pro-inflammatory" cytokines - interleukin (IL) 1 and IL-18, inducing the synthesis of other proinflammatory inflammatory mediators. A review of new data concerning the mechanisms of immunopathology, clinical polymorphism, laboratory biomarkers and the possibilities of ASD pharmacotherapy is presented. Particular attention is paid to the prospects for the use of monoclonal antibodies to IL-1beta - canakinumab. The problems associated with the generality of clinical and laboratory disorders, pathogenetic mechanisms and pharmacotherapy of ASD and coronavirus disease 2019 (COVID-19) are considered.Copyright © 2021 Authors. All rights reserved.
ABSTRACT
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.
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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-alpha in adipocyte cultures infected by SARS-CoV-2 spike protein and identify the possible mechanism involved. Material(s) and Method(s): 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 muM);P3: SARS-CoV-2 spike protein + anti-ACE2 antibody 100 mug/mL;and evaluated at 24 and 48 hours. ACE2 expression was evaluated using immunofluorescence. IL-6, TNFalpha, 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. Result(s): 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<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<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<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<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<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<0.01). However, no significant difference in TNFalpha and IL-1B expression between perindopril treatment and positive control in both 24 and 48 hours. Conclusion(s): 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.
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Post COVID-19 patients have been suffering from persistent symptoms even after long periods. The physiopathology of these clinical manifestations still has a lack of knowledge. The objective was to evaluate the total expression of metabolites and spittle biological pathways in patients with 60 days post COVID-19. We included 30 post-hospital discharge patients and we compared seven non COVID-19 patients control. All COVID-19 patients were assessed by demographic characteristics, pulmonary function, exercise capacity, quality of life and body composition. The metabolomic analysis was performed in the patient's splits. From the total of post COVID-19 patients, 66% were male, 60+/-14 years. The lean body mass was 30+/-7kg and fat mass 34+/-13kg. Spirometry mean severity showed FVC of 4+/-1L, FEV1 3+/-1L. Pimax and Pemax values were 90+/-31(cmH2O) and 97+/-31(cmH2O), respectively. The quality of life evaluated by the SGRQ questionnaire showed a mean percentage of magnitude of symptoms 32+/-15, activities 41+/-25, impact 13+/-11 and total of 24+/-15. Physical capacity was measured by the distance in the 6MWT, and presented an average of 413+/-131. The metabolomic analysis showed 19 metabolites statistically significant difference between groups. We observed 3 metabolites overexpressed and 16 with lower expression in post COVID19 patients. From those metabolites, we can have attention to Sphinganine(p=0.03), Piperenol A triacetate(p=0.02) and 1-Monopalmitin(p=0.03) were lower expressed in control group. The creatin was one of the non-expressed metabolites in post hospital discharge COVID-19 patients compared to the control group. Thus, metabolomic analysis can demonstrate different metabolites in post COVID-19 patients to answer persistent symptoms.
ABSTRACT
Patients with severe COVID-19-associated pneumonia are at risk to develop pulmonary fibrosis. To study the underlying mechanisms, we aim to develop advanced cell culture models that reliably reflect COVID-19-related profibrotic microenvironment. To identify key cellular players, we performed pilot immunohistochemistry analysis on lung tissue from COVID-19 patients with fibrosis collected during autopsy. Results revealed diffuse alveolar damage with macrophage infiltration, and myofibroblast accumulation with enriched collagen deposition surrounding the damaged alveoli. To mimic SARS-CoV-2 infection in alveoli, we infected human primary type II alveolar epithelial cells (AEC2) and found enhanced signaling of profibrotic cytokine transforming growth factor beta (TGFbeta) in some donors. To recreate the early fibrotic niche, an alveolar-macrophage-fibroblast (AMF) tri-culture model was established. After infecting AEC2 with SARS-CoV-2 in this AMF model, gene expression analysis provided evidence for fibroblast-to-myofibroblast transition. Furthermore, we found that overexpression of SARS-CoV-2 papain-like protease (PLpro) can promote TGFbeta signaling in HEK293T and A549 cells. After infecting AEC2 with SARS-CoV-2 PLpro lentivirus in the AMF model, we found signs of epithelial-to-mesenchymal transition and fibroblast-to myofibroblast transition. In future studies, we will use a detailed analysis of COVID-19-associated lung fibrosis with other types of lung fibrosis, to further refine COVID-19-related fibrosis models, including lung-on-chip models.
ABSTRACT
It has been widely acknowledged that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells via the angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) entry mechanism. However, ACE2 and TMPRSS2 cannot explain the Toll-like receptor driven response of monocytes since there is no ACE2 expressed on monocytes, suggesting alternative receptor(s) on these cells. Here, we report cell surface glucose-regulated protein 78 (csGRP78) which is abundantly expressed on monocytes to function as an alternative receptor for SARS-CoV-2 internalization. Our results show that csGRP78 is upregulated on the monocyte of COVID-19 patients. Moreover, in vitro cell culture experiments revealed that GRP78 over-expressing THP-1 cells and stimulation of wtTHP-1 cells with the relevant cytokines IL-1beta, IL-6, TNF and IFN-gamma induces similar csGRP78 and activation marker upregulation on cell surface as found on patients' monocytes. In vitro spike protein and GRP78 interaction tests (SPR assay, GST-pull down and Co-IP), confirmed direct binding of spike protein and GRP78. Finally, pseudo-typed virus expressing spike protein was used to infect mock or GRP78 over-expressing THP-1 cells. We found that pseudo-typed virus entered GRP78 over-expressing THP-1 cells but not control THP-1 cells. Our results demonstrate that csGRP78 acts as a potential functional receptor for SARS-CoV-2 spike protein and mediates ACE2 independent SARS-CoV-2 entry into monocytes. These findings provide insight into role of monocytes in the pathophysiology of COVID-19, and suggest a new therapeutic target candidate for anti-SARS-CoV2 treatment.