Contributions of human ACE2 and TMPRSS2 in determining host–pathogen interaction of COVID-19

The relationship between microRNAs and COVID-19 complications

Over the past three years, since the onset of COVID-19, several scientific studies have concentrated on understanding susceptibility to the virus, the progression of the illness, and possible long-term complexity. COVID-19 is broadly recognized with effects on multiple systems in the body, and various factors related to society, medicine, and genetics/epigenetics may contribute to the intensity and results of the disease. Additionally, a SARS-CoV-2 infection can activate pathological activities and expedite the emergence of existing health issues into clinical problems. Forming easily accessible, distinctive, and permeable biomarkers is essential for categorizing patients, preventing the disease, predicting its course, and tailoring treatments for COVID-19 individually. One promising candidate for such biomarkers is microRNAs, which could serve various purposes in understanding diverse forms of COVID-19, including susceptibility, intensity, disease progression, outcomes, and potential therapeutic options. This review provides an overview of the most significant findings related to the involvement of microRNAs in COVID-19 pathogenesis. Furthermore, it explores the function of microRNAs in a broad span of effects that may arise from accompanying or underlying health status. It underscores the value of comprehending how diverse conditions, such as neurological disorders, diabetes, cardiovascular diseases, and obesity, interact with COVID-19.

Gastroesophageal reflux disease increases predisposition to severe COVID-19: Insights from integrated Mendelian randomization and genetic analysis

OBJECTIVE

This study aims to investigate the potential causal relationship, shared genomic loci, as well as potential molecular pathways and tissue-specific expression patterns between gastroesophageal reflux disease (GERD) and the risk of hospitalized/severe 2019 coronavirus disease (COVID-19).

METHODS

We employed linkage disequilibrium score regression and bidirectional Mendelian randomization (MR) analysis to explore potential genetic associations between GERD (N = 602,604) and hospitalized COVID-19 (N = 2095,324) as well as severe COVID-19 (N = 1086,211). Additionally, shared genomic loci were extracted from common pivotal regions, further confirmed through corresponding colocalization analyses. GERD-driven molecular pathway network was constructed using extensive literature data mining to understand the molecular-level impacts of GERD on COVID-19.

RESULTS

Our results revealed a significant positive genetic correlation between GERD and both hospitalized (rg  =  0.418) and severe COVID-19 (rg  =  0.314). Furthermore, the MR analysis demonstrated a unidirectional causal effect of genetic predisposition to GERD on COVID-19 outcomes, including hospitalized COVID-19 (odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.27-1.44, p = 9.17e - 12) and severe COVID-19 (OR: 1.27, 95% CI: 1.18-1.37, p = 1.20e - 05). Additionally, GERD and both COVID-19 conditions shared one genomic locus with lead-SNPs rs1011407 and rs1123573, corresponding to the transcription factor BCL11A. Colocalization analysis further demonstrated a significant positive correlation between genome-wide association study and expression quantitative trait locus (eQTL) abnormalities, including rs1011407 (eQTL_p = 2.35e - 07) and rs1123573 (eQTL_p = 2.74e - 05). Molecular pathway analysis indicated that GERD might promote the progression of COVID-19 by inducting immune-activated and inflammation-related pathways.

CONCLUSION

These findings confirm that genetically determined GERD may increase the susceptibility to hospitalized/severe COVID-19. The shared genetic loci and the potential molecular pathways offer valuable insights into causal connections between GERD and COVID-19.

Prevalence of Toxoplasma gondii infection in COVID-19 patients: A systematic review and meta-analysis

Toxoplasma gondii is a parasite that affects over one billion people worldwide. COVID-19, caused by the SARS-CoV-2 virus, has resulted in over 4.8 million deaths worldwide. Both diseases activate the innate immune response via the same pathway. Studies have suggested that toxoplasmosis may either protect against or worsen the severity of COVID-19. This meta-analysis investigated the relationship between toxoplasmosis prevalence and COVID-19. The selection of studies was based on a systematic search using specific keywords in Scopus, Web of Science, PubMed, and Google Scholar databases between 2019 and 2023. The study findings were analyzed using STATA software version 17.0, and the prevalence of toxoplasmosis in people with COVID-19 and its confidence interval were extracted from the selected studies. The study's heterogeneity was assessed using the I2 test, and publication bias was evaluated using a funnel plot and Egger's test. A p value of 0.05 was considered significant. The meta-analysis included nine studies with a total of 1745 COVID-19-positive individuals, and the results showed a significant association between toxoplasmosis and COVID-19 severity. The I2 statistic was almost 99 %, indicating large heterogeneity among the studies. The Egger's test showed no publication bias. The pooled prevalence of toxoplasmosis in COVID-19-positive individuals was 0.48 (95 % CI: 0.30-0.66), which was significantly different from that of 0 % (P < 0.001). The meta-analysis found that the prevalence oftoxoplasmosis was significantly higher in individuals with COVID-19 than in the general population, indicating a possible association between the two infections. However, the significant heterogeneity among the studies underscores the need for further research to understand the underlying mechanisms and clinical implications of this association.

Impact of genetic variations of gene involved in regulation of metabolism, inflammation and coagulation on pathogenesis of cardiac injuries associated with COVID-19

BACKGROUND

SARS-CoV-2 infection can result in long-term chronic cardiovascular (CV) damage after the acute phase of the illness. COVID-19 frequently causes active myocarditis, SARS-CoV-2 can directly infect and kill cardiac cells, causing severe pathology and dysfunction across the organs and cells. Till now, the pathogenesis of COVID-19-associated cardiac injuries has not been understood, but there are several factors that contribute to the progression of cardiac injuries, such as genetic, dietary, and environmental. Among them ranges of host genetic factor including metabolizing, inflammation, and coagulation related genes have a role to contribute the cardiac injuries induced by COVID-19. Hereditary DNA sequence variations contribute to the risk of illness in almost all of these diseases. Hence, we comprehended the occurrence of genetic variations of metabolizing, inflammation and coagulation-related genes in the general population, their expression in various diseases, and their impact on cardiac injuries induced by COVID-19.

METHOD

We utilized multiple databases, including PubMed (Medline), EMBASE, and Google Scholar, for literature searches.

DESCRIPTION

The genes involved in metabolism (APOE, MTHFR), coagulation (PAI-1, ACE2), and immune factors (CRP, ESR, and troponin I) may have a role in the progression of COVID-19-associated cardiac injuries. The risk factors for CVD are significantly varied between and within different regions. In healthy individuals, the ACE I allele is responsible for the predisposition to CAD, but the ACE D haplotype is responsible for susceptibility and severity, which ultimately leads to heart failure. Patients who carry the T allele of rs12329760 in the TMPRSS2 gene are at risk for developing the severe form of COVID-19. IL-6 (rs1800796/rs1800795) polymorphism is associated with an increased mortality rate and susceptibility to severe COVID-19 disease. While the putative role of IL-6 associated with chronic, inflammatory diseases like cardiac and cerebrovascular disease is well known.

CONCLUSION

The occurrence of genetic variations in the ACE-2, AGT, DPP-IV, TMPRSS2, FUIRN, IL-4, IL-6, IFN-γ, and CYP2D6 genes is varied among different populations. Examining the correlation between these variations and their protein levels and cardiac injuries induced by COVID-19 may provide valuable insights into the pathogenesis of cardiac injuries induced by COVID-19.

Impacts of host factors on susceptibility to SARS-CoV-2 infection and COVID-19 progression

SARS-CoV-2, identified in Wuhan, China, in December 2019, is the third coronavirus responsible for a global epidemic, following SARS-CoV (2002) and MERS-CoV (2012). Given the recent emergence of COVID-19, comprehensive immunological data are still limited. The susceptibility and severity of SARS-CoV-2 infection are influenced by various host factors, including hormonal changes, genetic variations, inflammatory biomarkers, and behavioral attitudes. Identifying genetic factors contributing to infection severity may accelerate therapeutic development, including drug repurposing, natural extracts, and post-vaccine interventions (Initiative and Covid, 2021). This review discusses the human protein machinery involved in (a) SARS-CoV-2 host receptors, (b) the human immune response, and (c) the impact of demographic and genetic differences on individual risk for COVID-19. This review aims to clarify host factors implicated in SARS-CoV-2 susceptibility and progression, highlighting potential therapeutic targets and supportive treatment strategies.

Identification and evaluation of candidate COVID-19 critical genes and medicinal drugs related to plasma cells

The ongoing COVID-19 pandemic, caused by the SARS-CoV-2 virus, represents one of the most significant global health crises in recent history. Despite extensive research into the immune mechanisms and therapeutic options for COVID-19, there remains a paucity of studies focusing on plasma cells. In this study, we utilized the DESeq2 package to identify differentially expressed genes (DEGs) between COVID-19 patients and controls using datasets GSE157103 and GSE152641. We employed the xCell algorithm to perform immune infiltration analyses, revealing notably elevated levels of plasma cells in COVID-19 patients compared to healthy individuals. Subsequently, we applied the Weighted Gene Co-expression Network Analysis (WGCNA) algorithm to identify COVID-19 related plasma cell module genes. Further, positive cluster biomarker genes for plasma cells were extracted from single-cell RNA sequencing data (GSE171524), leading to the identification of 122 shared genes implicated in critical biological processes such as cell cycle regulation and viral infection pathways. We constructed a robust protein-protein interaction (PPI) network comprising 89 genes using Cytoscape, and identified 20 hub genes through cytoHubba. These genes were validated in external datasets (GSE152418 and GSE179627). Additionally, we identified three potential small molecules (GSK-1070916, BRD-K89997465, and idarubicin) that target key hub genes in the network, suggesting a novel therapeutic approach. These compounds were characterized by their ability to down-regulate AURKB, KIF11, and TOP2A effectively, as evidenced by their low free binding energies determined through computational analyses using cMAP and AutoDock. This study marks the first comprehensive exploration of plasma cells' role in COVID-19, offering new insights and potential therapeutic targets. It underscores the importance of a systematic approach to understanding and treating COVID-19, expanding the current body of knowledge and providing a foundation for future research.

DON/DRP-104 as potent serine protease inhibitors implicated in SARS-CoV-2 infection: Comparative binding modes with human TMPRSS2 and novel therapeutic approach

Human transmembrane serine protease 2 (TMPRSS2) is an important member of the type 2 transmembrane serine protease (TTSP) family with significant therapeutic markings. The search for potent TMPRSS2 inhibitors against severe acute respiratory syndrome coronavirus 2 infection with favorable tissue specificity and off-site toxicity profiles remains limited. Therefore, probing the anti-TMPRSS2 potential of enhanced drug delivery systems, such as nanotechnology and prodrug systems, has become compelling. We report the first in silico study of TMPRSS2 against a prodrug, [isopropyl(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5-oxo-hexanoate] also known as DRP-104 synthesized from 6-Diazo-5-oxo-l-norleucine (DON). We performed comparative studies on DON and DRP-104 against a clinically potent TMPRSS2 inhibitor, nafamostat, and a standard serine protease inhibitor, 4-(2-Aminoethyl) benzenesulfonyl fluoride (AEBSF) against TMPRSS2 and found improved TMPRSS2 inhibition through synergistic binding of the S1/S1' subdomains. Both DON and DRP-104 had better thermodynamic profiles than AEBSF and nafamostat. DON was found to confer structural stability with strong positive correlated inter-residue motions, whereas DRP-104 was found to confer kinetic stability with restricted residue displacements and reduced loop flexibility. Interestingly, the Scavenger Receptor Cysteine-Rich (SRCR) domain of TMPRSS2 may be involved in its inhibition mechanics. Two previously unidentified loops, designated X (270-275) and Y (293-296) underwent minimal and major structural transitions, respectively. In addition, residues 273-277 consistently transitioned to a turn conformation in all ligated systems, whereas unique transitions were identified for other transitioning residue groups in each TMPRSS2-inhibitor complex. Intriguingly, while both DON and DRP-104 showed similar loop transition patterns, DRP-104 preserved loop structural integrity. As evident from our systematic comparative study using experimentally/clinically validated inhibitors, DRP-104 may serve as a potent and novel TMPRSS2 inhibitor and warrants further clinical investigation.

Role of ACE2 and TMPRSS2 polymorphisms on COVID-19 outcome and disease severity in adult patients: A prospective cohort study in a tertiary hospital, Indonesia

Coronavirus disease 2019 (COVID-19) has led to a significant number of infections and deaths worldwide, yet its pathogenesis and severity remain incompletely understood. Angiotensin-converting enzyme 2 (ACE2) and transmembrane protease, serine 2 (TMPRSS2), play crucial roles as receptors and molecules responsible for the virus's entry into host cells, initiating the infection process. Their polymorphisms have been extensively studied in relation to COVID-19 severity. The aim of this study was to examine the association of ACE2 (rs2074192) and TMPRSS2 (rs12329760) polymorphisms with COVID-19 outcome and severity. A prospective cohort study was conducted in 2022 at Haji Adam Malik Hospital, Medan, Indonesia. We randomly recruited hospitalized adult patients with COVID-19, confirmed by real-time polymerase chain reaction (RT-PCR). The baseline demographic data, disease severity, underlying disease, comorbidities, and COVID-19 vaccination status were collected. The single-nucleotide polymorphism (SNP) was assessed using TaqMan SNP genotyping assay, and the levels of TMPRSS2 and ACE2 proteins were measured using enzyme-linked immunosorbent assay (ELISA). A total of 151 COVID-19 patients were recruited and there were significant associations between age and severity with mortality outcomes. The age, kidney and lung diseases, and vaccination status were associated with severity levels. The results showed the CC genotype of ACE2 had the highest proportion, followed by TT and CT genotypes among patients, while CT was the most prevalent genotype, followed by CC and TT for TMPRSS2. This study did not find a significant association between ACE2 and TMPRSS2 genetic variants with disease severity and outcome but highlighted a specific association of TMPRSS2 SNP with mortality within the group. In addition, ACE2 concentration was significant different between mild-moderate and severe-critical COVID-19 groups (p=0.033).

Evaluation of oral health status and immunological parameters of hospitalized COVID-19 patients during acute and recovery phases: A randomized clinical trial

Background/purpose

It is known that COVID-19 patients show many clinical oral symptoms due to the immunological mechanisms triggered by the virus. Aim of this study is to analyze the antibody response to SARS-CoV-2, and to evaluate the oral health status of hospitalized patients.

Materials and methods

160 patients with COVID-19 confirmed by SARS-CoV-2-specific RT-PCR testing and 160 healthy volunteers (HI) with similar age, gender and systemic status were included to compare the bio-chemical and oral manifestations. Oropharyngeal swab specimens were collected to evaluate the salivary interleukins (IL-1, IL-6, IL-10) and immunoglobulins (sIgA, sIgG, sIgM). Oral findings (DMFT, plaque index, salivary flow rate), socio-demographic information and systemic conditions were also recorded. Chi-square, Mann-Whitney U and Spearman's ratio tests were applied to determine the possible correlations between the factors (P = 0.05).

Results

The mean DMFT scores of COVID-19 patients (12.71 ± 7.3) were significantly higher than the HI (7.39 ± 2.8), whereas cases of total or partial edentulism were more common among COVID-19 patients (P < 0.05). While plaque index scores were similar for both groups (P > 0.05), salivary parameters were found statistically different (P < 0.05). Severe and moderate cases showed higher proinflammatory interleukin levels (IL-1 = 68.74 pg/ml, IL-6 = 53.31 pg/ml) amongst all (P < 0.05). While secretory immunoglobulins were almost depleted at baseline, (sIgA = 0.11 mg/ml, sIgG = 0.21 mg/ml, sIgM = 0.08 mg/ml) they reached to threshold levels after 4 weeks.

Conclusion

Higher proinflammatory interleukin levels indicated that traces of ongoing "Cytokine Storm" in COVID-19 patients which can also be observed in oral environment. Poor oral hygiene and malnutrition due to edentulism can pave the way for having a severe COVID-19 infection.

A Study on the Impact of the COVID-19 Pandemic on the Aetiology of Paediatric Olfactory Dysfunction

INTRODUCTION

Although previous studies have examined olfactory dysfunction in children, the novel coronavirus SARS-CoV-2 has certainly had an unprecedented effect on their olfaction, which could not be taken into consideration. The aim of this report was to present data on the epidemiology of olfactory dysfunction during the pandemic and compare this dataset with a pre-pandemic set. We hypothesized an increase in URTI-related olfactory dysfunction.

METHODS

Data of paediatric patients consulting a smell and taste clinic between March 2020 and June 2022 were retrospectively analysed. The frequency of major causes of olfactory dysfunction was examined and compared with three subsets of an older dataset.

RESULTS

A total of 52 patients were included in the analysis. Most children presented with olfactory dysfunction due to upper respiratory tract infection (URTI) (52%). Congenital olfactory dysfunction was present in 34% of cases. Sinonasal disorders and idiopathic cases accounted for 6 and 4%, respectively, whereas head trauma was the least common cause (2%). This was in contrast with the results of the older set. The frequency of URTI-related olfactory dysfunction increased significantly. The frequency of head-trauma-related or congenital olfactory dysfunction showed marked reductions. There were no significant differences regarding the other aetiologies between our patient cohort and the three subsets.

CONCLUSION

The COVID-19 pandemic has resulted in differences regarding the prevalence of aetiologies between our dataset and the subsets of pre-pandemic times. The surge of the frequency of URTI-related olfactory dysfunction may be ascribed to a novel pathomechanism involving sustentacular cells in the olfactory epithelium.

"Every Cloud Has a Silver Lining": How Three Rare Diseases Defend Themselves from COVID-19 and What We Have Learnt from It

The process of SARS-CoV-2 infection, responsible for the COVID-19 pandemic, is carried out through different steps, with the interaction between ACE2 and Spike protein (S) being crucial. Besides of that, the acidic environment of endosomes seems to play a relevant role in the virus uptake into cells and its intracellular replication. Patients affected by two rare genetic tubulopathies, Gitelman's and Bartter's Syndromes, and a rare genetic metabolic disease, Fabry Disease, have shown intrinsic protection from SARS-CoV-2 infection and COVID-19 on account of specific intrinsic features that interfere with the virus uptake into cells and its intracellular replication, which will be reported and discussed in this paper, providing interesting insights for present and future research.

The fatal contribution of serine protease-related genetic variants to COVID-19 outcomes

Introduction

Serine proteases play a critical role during SARS-CoV-2 infection. Therefore, polymorphisms of transmembrane protease serine 2 (TMPRSS2) and serpine family E member 1 (SERPINE1) could help to elucidate the contribution of variability to COVID-19 outcomes.

Methods

To evaluate the genetic variants of the genes previously associated with COVID-19 outcomes, we performed a cross-sectional study in which 1536 SARS-CoV-2-positive participants were enrolled. TMPRSS2 (rs2070788, rs75603675, rs12329760) and SERPINE1 (rs2227631, rs2227667, rs2070682, rs2227692) were genotyped using the Open Array Platform. The association of polymorphisms with disease outcomes was determined by logistic regression analysis adjusted for covariates (age, sex, hypertension, type 2 diabetes, and obesity).

Results

According to our codominant model, the GA genotype of rs2227667 (OR=0.55; 95% CI = 0.36-0.84; p=0.006) and the AG genotype of rs2227667 (OR=0.59; 95% CI = 0.38-0.91; p=0.02) of SERPINE1 played a protective role against disease. However, the rs2227692 T allele and TT genotype SERPINE1 (OR=1.45; 95% CI = 1.11-1.91; p=0.006; OR=2.08; 95% CI = 1.22-3.57; p=0.007; respectively) were associated with a decreased risk of death. Similarly, the rs75603675 AA genotype TMPRSS2 had an OR of 1.97 (95% CI = 1.07-3.6; p=0.03) for deceased patients. Finally, the rs2227692 T allele SERPINE1 was associated with increased D-dimer levels (OR=1.24; 95% CI = 1.03-1.48; p=0.02).

Discussion

Our data suggest that the rs75603675 TMPRSS2 and rs2227692 SERPINE1 polymorphisms are associated with a poor outcome. Additionally, rs2227692 SERPINE1 could participate in hypercoagulable conditions in critical COVID-19 patients, and this genetic variant could contribute to the identification of new pharmacological targets and treatment strategies to block the inhibition of TMPRSS2 entry into SARS-CoV-2.

Modulating effect of Eunkyo-san on expression of inflammatory cytokines and angiotensin-converting enzyme 2 in human mast cells

Eunkyo-san is widely used in the treatment of severe respiratory infections. Mast cells not only serve as host cells for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but also they also exacerbate Coronavirus disease in 2019 (COVID-19) by causing a cytokine storm. Here we investigated whether Eunkyo-san and its active compound naringenin regulate the expression of inflammatory cytokines and factors connected to viral infection in activated human mast cell line, HMC-1 cells. Eunkyo-san and naringenin significantly reduced levels of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, thymic stromal lymphopoietin, and tumor necrosis factor-α without impacting cytotoxicity. Eunkyo-san and naringenin reduced levels of factors connected to SARS-CoV-2 infection such as angiotensin-converting enzyme 2 (ACE2, SARS-CoV-2 receptor), transmembrane protease/serine subfamily member 2, and tryptase in activated HMC-1 cells. Treatment with Eunkyo-san and naringenin considerably reduced expression levels of ACE2 transcription factor, AP-1 (C-JUN and C-FOS) by blocking phosphatidylinositide-3-kinase and c-Jun NH2-terminal kinases signaling pathways. In addition, Eunkyo-san and naringenin effectively suppressed activation of signal transducer and activator of transcription 3, nuclear translocation of nuclear factor-κB, and activation of caspase-1 in activated HMC-1 cells. Furthermore, Eunkyo-san and naringenin reduced expression of ACE2 mRNA in two activated mast cell lines, RBL-2H3 and IC-2 cells. The overall study findings showed that Eunkyo-san diminished the expression levels of inflammatory cytokines and ACE2, and these findings imply that Eunkyo-san is able to effectively mitigating the cytokine storm brought on by SARS-CoV-2 infection.

The Growing Understanding of the Pituitary Implication in the Pathogenesis of Long COVID-19 Syndrome: A Narrative Review

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation. This can result in symptoms such as fatigue, changes in appetite, and mood disturbances. Long COVID-19, the persistent and often debilitating condition following acute COVID-19 infection, may be explained by deficiencies in ACTH and Growth hormone production from the pituitary gland. Corticotropin insufficiency can result in the dysregulation of the body's stress response and can lead to prolonged feelings of stress, fatigue, and mood disturbances in Long COVID-19 patients. Simultaneously, somatotropin insufficiency can affect growth, muscle function, and energy metabolism, potentially causing symptoms such as muscle weakness, exercise intolerance, and changes in body composition. Recently, some authors have suggested the involvement of the pituitary gland in Post COVID-19 Syndrome. The exact mechanisms of viral action on infected cells remain under discussion, but inflammatory and autoimmune mechanisms are primarily implicated. The aim of our study will be to review the main pituitary complications following COVID-19 infection. Moreover, we will explain the possible involvement of the pituitary gland in the persistence of Post COVID-19 Syndrome.

Explaining Long COVID: A Pioneer Cross-Sectional Study Supporting the Endocrine Hypothesis

Context

In some patients, symptoms may persist after COVID-19, defined as long COVID. Its pathogenesis is still debated and many hypotheses have been raised.

Objective

Our primary objective was to evaluate the corticotroph and somatotroph functions of patients previously infected with SARS-CoV-2 and experiencing post-COVID-19 syndrome to detect any deficiencies that may explain long COVID.

Methods

A cross-sectional study was conducted including patients who had previously contracted SARS-CoV-2 with a postinfection period of 3 months or less to 15 months, divided into 2 groups. The first group (G1) comprised fully recovered patients, while the second group (G2) included patients experiencing long COVID. The primary outcome was the comparison of corticotroph and somatotroph functions.

Results

A total of 64 patients were divided into 2 groups, each consisting of 32 patients. G2 exhibited more frequently anterior pituitary deficits compared to G1 (P = .045): for the corticotroph axis (G1: 6.3% vs G2: 28.1%) and for the somatotroph axis (G1: 31.3% vs G2: 59.4%). Baseline cortisol level was significantly lower in G2 (G1: 13.37 µg/dL vs G2: 11.59 µg/dL) (P = .045). The peak cortisol level was also lower in G2 (G1: 23.60 µg/dL vs G2: 19.14 µg/dL) (P = .01). For the somatotroph axis, the insulin growth factor-1 level was lower in G2 (G1: 146.03 ng/mL vs G2: 132.25 ng/mL) (P = .369). The peak growth hormone level was also lower in G2 (G1: 4.82 ng/mL vs G2: 2.89 ng/mL) (P = .041).

Conclusion

The results showed that long COVID patients in our cohort were more likely to have anterior pituitary deficiencies. The endocrine hypothesis involving anterior pituitary insufficiency can be considered to explain long COVID.

Lipid Metabolism Modulation during SARS-CoV-2 Infection: A Spotlight on Extracellular Vesicles and Therapeutic Prospects

Extracellular vesicles (EVs) have a significant impact on the pathophysiological processes associated with various diseases such as tumors, inflammation, and infection. They exhibit molecular, biochemical, and entry control characteristics similar to viral infections. Viruses, on the other hand, depend on host metabolic machineries to fulfill their biosynthetic requirements. Due to potential advantages such as biocompatibility, biodegradation, and efficient immune activation, EVs have emerged as potential therapeutic targets against the SARS-CoV-2 infection. Studies on COVID-19 patients have shown that they frequently have dysregulated lipid profiles, which are associated with an increased risk of severe repercussions. Lipid droplets (LDs) serve as organelles with significant roles in lipid metabolism and energy homeostasis as well as having a wide range of functions in infections. The down-modulation of lipids, such as sphingolipid ceramide and eicosanoids, or of the transcriptional factors involved in lipogenesis seem to inhibit the viral multiplication, suggesting their involvement in the virus replication and pathogenesis as well as highlighting their potential as targets for drug development. Hence, this review focuses on the role of modulation of lipid metabolism and EVs in the mechanism of immune system evasion during SARS-CoV-2 infection and explores the therapeutic potential of EVs as well as application for delivering therapeutic substances to mitigate viral infections.

Mechanisms of SARS-CoV-2 Placental Transmission

The widespread occurrence of SARS-CoV-2 infections and the diverse range of symptoms have placed significant strain on healthcare systems worldwide. Pregnancy has also been affected by COVID-19, with an increased risk of complications and unfavorable outcomes for expectant mothers. Multiple studies indicate that SARS-CoV-2 can infiltrate the placenta, breach its protective barrier, and infect the fetus. Although the precise mechanisms of intrauterine transmission remain unclear, factors such as perinatal infection, macrophages, sexual intercourse, and the virus' interaction with host angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP-1) proteins appear to play a role in this process. The integrity of the placental barrier fluctuates throughout pregnancy and appears to influence the likelihood of fetal transmission. The expression of placental cell receptors, like ACE2, changes during pregnancy and in response to placental damage. However, due to the consistent presence of others, such as NRP-1, SARS-CoV-2 may potentially enter the fetus at different stages of pregnancy. NRP-1 is also found in macrophages, implicating maternal macrophages and Hofbauer cells as potential routes for viral transmission. Our current understanding of SARS-CoV-2's vertical transmission pathways remains limited. Some researchers question the ACE2-associated transmission model due to the relatively low expression of ACE2 in the placenta. Existing studies investigating perinatal transmission and the impact of sexual intercourse have either involved small sample sizes or lacked statistical significance. This review aims to explore the current state of knowledge regarding the potential mechanisms of COVID-19 vertical transmission, identifying areas where further research is needed to fill the gaps in our understanding.

New Insights into the Link between SARS-CoV-2 Infection and Renal Cancer

Cancer has been described as a risk factor for greater susceptibility to SARS-CoV-2 infection and severe COVID-19, mainly for patients with metastatic disease. Conversely, to that reported for most solid and hematological malignancies, the few available clinical studies reported that the infection did not increase the risk of death in renal cancer patients. The expression on proximal tubular renal cells of the key players in cellular viral uptake, ACE2, TMPRSS2, and NRP1, seems to be the mechanism for the direct kidney injury seen in patients with COVID-19. Interestingly, data from The Cancer Genome Atlas and experimental analyses on various renal cancer cell lines demonstrated that the above-reported receptors/cofactors are maintained by renal cancer cells. However, whether SARS-CoV-2 infection directly kills renal cancer cells or generates enhanced immunogenicity is a question worth investigating. In addition, some researchers have further addressed the topic by studying the expression and prognostic significance of gene signatures related to SARS-CoV-2 infection in renal cancer patients. The emerging data highlights the importance of better understanding the existence of a link between renal cancer and COVID-19 since it could lead to the identification of new prognostic factors and the development of new therapeutic targets in the management of renal cancer patients.

Development of a novel machine learning model based on laboratory and imaging indices to predict acute cardiac injury in cancer patients with COVID-19 infection: a retrospective observational study

PURPOSE

Due to the increased risk of acute cardiac injury (ACI) and poor prognosis in cancer patients with COVID-19 infection, our aim was to develop a novel and interpretable model for predicting ACI occurrence in cancer patients with COVID-19 infection.

METHODS

This retrospective observational study screened 740 cancer patients with COVID-19 infection from December 2022 to April 2023. The least absolute shrinkage and selection operator (LASSO) regression was used for the preliminary screening of the indices. To enhance the model accuracy, we introduced an alpha index to further screen and rank the indices based on their significance. Random forest (RF) was used to construct the prediction model. The Shapley Additive Explanation (SHAP) and Local Interpretable Model-Agnostic Explanation (LIME) methods were utilized to explain the model.

RESULTS

According to the inclusion criteria, 201 cancer patients with COVID-19, including 36 variables indices, were included in the analysis. The top eight indices (albumin, lactate dehydrogenase, cystatin C, neutrophil count, creatine kinase isoenzyme, red blood cell distribution width, D-dimer and chest computed tomography) for predicting the occurrence of ACI in cancer patients with COVID-19 infection were included in the RF model. The model achieved an area under curve (AUC) of 0.940, an accuracy of 0.866, a sensitivity of 0.750 and a specificity of 0.900. The calibration curve and decision curve analysis showed good calibration and clinical practicability. SHAP results demonstrated that albumin was the most important index for predicting the occurrence of ACI. LIME results showed that the model could predict the probability of ACI in each cancer patient infected with COVID-19 individually.

CONCLUSION

We developed a novel machine-learning model that demonstrates high explainability and accuracy in predicting the occurrence of ACI in cancer patients with COVID-19 infection, using laboratory and imaging indices.

Targeting Viral ORF3a Protein: A New Approach to Mitigate COVID-19 Induced Immune Cell Apoptosis and Associated Respiratory Complications

Infection with SARS-CoV-2 is a growing concern to the global well-being of the public at present. Different amino acid mutations alter the biological and epidemiological characteristics, as well as immune resistance of SARS-CoV-2. The virus-induced pulmonary impairment and inflammatory cytokine storm are directly related to its clinical manifestations. But, the fundamental mechanisms of inflammatory responses are found to be the reason for the death of immune cells which render the host immune system failure. Apoptosis of immune cells is one of the most common forms of programmed cell death induced by the virus for its survival and virulence property. ORF3a, a SARS-CoV-2 accessory viral protein, induces apoptosis in host cells and suppress the defense mechanism. This suggests, inhibiting SARS-CoV-2 ORF3a protein is a good therapeutic strategy for the treatment in COVID-19 infection by promoting the host immune defense mechanism.

Transmembrane serine protease 2, a SARS-CoV-2 internalization protease, correlates with clinical outcome, molecular features, and immunotherapy response in colorectal cancer

Background

Transmembrane serine protease 2 (TMPRSS2) mediates the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. The relevant research indicates the intestine to be a target of SARS-CoV-2 infection, and thus we aimed to investigate the correlation between TMPRSS2 expression and the prognosis, molecular features, and immunotherapy response in patients with colorectal cancer (CRC).

Methods

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used in this study and a total of 1,385 patients were identified. The CIBERSORT algorithms were used to evaluate the relative infiltration levels of immune cell types in the tumor microenvironment (TME). The correlation between TMPRSS2 expression and immunotherapy response rate was assessed in another 2 independent cohorts.

Results

TMPRSS2 expression was significantly downregulated in cancer tissue compared to the adjacent normal tissue, and patients with CRC with lower TMPRSS2 expression showed notably poorer prognosis. Functional enrichment analysis found that low TMPRSS2 expression was significantly associated with cancer metastasis-related pathways. Further analysis based on the miRWalk tool and JASPAR database identified a list of microRNAs (miRNAs) and transcriptional factors targeting TMPRSS2. Distinct differences in immune cell infiltration and tumor purity reflected by estimate and mutant-allele tumor heterogeneity score were observed between patients with low and high TMPRSS2 expression levels. Interestingly, patients with a low TMPRSS2 expression level showed a higher response rate to immunotherapy.

Conclusions

CRC cells may be more resistant to SARS-CoV-2 infection due to the decreased expression of TMPRSS2, which could be a newly identified biomarker for prognosis and immunotherapy response prediction in patients with CRC.

Unraveling the Link between Periodontitis and Coronavirus Disease 2019: Exploring Pathogenic Pathways and Clinical Implications

Periodontitis involves the inflammation of the periodontal tissue, leading to tissue loss, while coronavirus disease 2019 (COVID-19) is a highly transmissible respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is amplified by poor systemic health. Key facilitators of SARS-CoV-2's entry into host cells are angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). This review reveals that periodontal pockets can serve as a hotspot for virus accumulation, rendering surrounding epithelia more susceptible to infection. Given that ACE2 is expressed in oral mucosa, it is reasonable to suggest that poor periodontal health could increase the risk of COVID-19 infection. However, recent studies have not provided sufficient evidence to imply a significant effect of COVID-19 on periodontal health, necessitating further and more long-term investigations. Nevertheless, there are hypotheses linking the mechanisms of the two diseases, such as the involvement of interleukin-17 (IL-17). Elevated IL-17 levels are observed in both COVID-19 and periodontitis, leading to increased osteoclast activity and bone resorption. Lastly, bidirectional relationships between periodontitis and systemic diseases like diabetes are acknowledged. Given that COVID-19 symptoms may worsen with these conditions, maintaining good oral health and managing systemic diseases are suggested as potential ways to protect against COVID-19.

Impact of ACE2 gene variations on COVID-19 pathogenicity in Pakistani patients

Background

COVID-19, caused by the SARS-CoV-2 virus, swiftly disseminated and was declared a pandemic. Variations in the ACE2 gene can impact the virus's ability to bind to ACE2 receptor, potentially influencing an individual's susceptibility and its association with COVID-19 severity across various populations.

Methods

In total, 200 individuals were sequenced for the ACE2 gene and potential impact of the found variants on the ACE2 protein was assessed using in-silico tools.

Results

Eight variations in the ACE2 gene were identified in 27 COVID-19 patients, of which four were missense and four were intronic variants. Three variants had a MAF of < 0.01 (c.251C > T, p.Pro86Leu; 15C > G, p.S5S; and c. 91 A > G, p.Lys31Glu). A missense variant, p.Pro86Leu, C > T, TT genotype, was found in 9 out of 200 individuals with an allele frequency of 0.045 and showed a significant association with COVID-19 (P = 0.003). The heterozygous allele of 15C > G, p.S5S, was found with a frequency of 0.02 (8/400) in eight patients, and its CG genotype showed a significant association with COVID-19 (P = 0.0068). The remaining identified variants were not associated with COVID-19 susceptibility.

Conclusion

The ACE2 gene sequence in Pakistani individuals exhibited a low frequency of identified variants in COVID-19 patients. Overall, only two variants were associated with susceptibility to the disease, possibly contributing to Pakistan's lower COVID-19 mortality and infection rates. However, individuals carrying the mutant variant experienced more severe symptoms.

Inflammatory markers and COVID-19 disease progression

BACKGROUND

The COVID-19 pandemic has resulted in a global humanitarian crisis. Despite ongoing research, transmission risks and many disease characteristics remained unclear. Most patients have displayed elevated levels of certain inflammatory markers, which we sought to investigate further in relation to disease severity. The aim of this study was to examine the correlation between inflammatory markers and the severity of COVID-19 among patients.

METHODS

We conducted a cross-sectional study from April to September 2020, involving 143 COVID-19 PCR-positive patients from Ziauddin Hospital. Electronic patient records provided data on demographics, clinical status, and laboratory results.

RESULTS

The majority of PCR-positive patients were elderly males with comorbidities such as diabetes and hypertension. Almost all patients exhibited increased levels of various inflammatory markers, with procalcitonin (97.2%) being the most common. Statistically significant differences were observed in the levels of TLC (p = 0.005), CRP (p = 0.001), LDH (p = 0.001), Ferritin (p = 0.001), D-dimer (p = 0.001), and procalcitonin (p = 0.028), in relation to COVID-19 severity.

CONCLUSIONS

The data suggest a significant association between levels of inflammatory markers and COVID-19 severity. All markers, except procalcitonin, demonstrated a significant correlation with disease severity. These results could enhance our understanding of COVID-19 pathogenesis and help predict and manage severe cases.

Endothelial dysfunction in autoimmune, pulmonary, and kidney systems, and exercise tolerance following SARS-CoV-2 infection

Long COVID is characterized by persistent symptoms beyond 3-months of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection that last for at least 2 months and cannot be explained by an alternative diagnosis. Autonomic, immunologic, endothelial, and hypercoagulation are implicated as possible mechanisms of long COVID symptoms. Despite recognition of the public health challenges posed by long COVID, the current understanding of the pathophysiological underpinnings is still evolving. In this narrative review, we explore the long-term effects of SARS-CoV-2 infection on T cell activation such as autoimmune disorders and endothelial cell dysfunction involving vascular impairments within pulmonary and renal architecture. We have described how endothelial dysfunction and vascular abnormalities may underscore findings of exercise intolerance by way of impaired peripheral oxygen extraction in individuals with long COVID.

Gestational Viral Infections: Role of Host Immune System

Viral infections in pregnancy are major causes of maternal and fetal morbidity and mortality. Infections can develop in the neonate transplacentally, perinatally, or postnatally (from breast milk or other sources) and lead to different clinical manifestations, depending on the viral agent and the gestational age at exposure. Viewing the peculiar tolerogenic status which characterizes pregnancy, viruses could exploit this peculiar immunological status to spread or affect the maternal immune system, adopting several evasion strategies. In fact, both DNA and RNA virus might have a deep impact on both innate and acquired immune systems. For this reason, investigating the interaction with these pathogens and the host's immune system during pregnancy is crucial not only for the development of most effective therapies and diagnosis but mostly for prevention. In this review, we will analyze some of the most important DNA and RNA viruses related to gestational infections.

Analyzing the role of ACE2, AR, MX1 and TMPRSS2 genetic markers for COVID-19 severity

BACKGROUND

The use of molecular biomarkers for COVID-19 remains unconclusive. The application of a molecular biomarker in combination with clinical ones that could help classifying aggressive patients in first steps of the disease could help clinician and sanitary system a better management of the disease. Here we characterize the role of ACE2, AR, MX1, ERG, ETV5 and TMPRSS2 for trying a better classification of COVID-19 through knowledge of the disease mechanisms.

METHODS

A total of 329 blood samples were genotyped in ACE2, MX1 and TMPRSS2. RNA analyses were also performed from 258 available samples using quantitative polymerase chain reaction for genes: ERG, ETV5, AR, MX1, ACE2, and TMPRSS2. Moreover, in silico analysis variant effect predictor, ClinVar, IPA, DAVID, GTEx, STRING and miRDB database was also performed. Clinical and demographic data were recruited from all participants following WHO classification criteria.

RESULTS

We confirm the use of ferritin (p < 0.001), D-dimer (p < 0.010), CRP (p < 0.001) and LDH (p < 0.001) as markers for distinguishing mild and severe cohorts. Expression studies showed that MX1 and AR are significantly higher expressed in mild vs severe patients (p < 0.05). ACE2 and TMPRSS2 are involved in the same molecular process of membrane fusion (p = 4.4 × 10^-3), acting as proteases (p = 0.047).

CONCLUSIONS

In addition to the key role of TMPSRSS2, we reported for the first time that higher expression levels of AR are related with a decreased risk of severe COVID-19 disease in females. Moreover, functional analysis demonstrates that ACE2, MX1 and TMPRSS2 are relevant markers in this disease.

Different In Silico Approaches Using Heterocyclic Derivatives against the Binding between Different Lineages of SARS-CoV-2 and ACE2

Over the last few years, the study of the SARS-CoV-2 spike protein and its mutations has become essential in understanding how it interacts with human host receptors. Since the crystallized structure of the spike protein bound to the angiotensin-converting enzyme 2 (ACE2) receptor was released (PDB code 6M0J), in silico studies have been performed to understand the interactions between these two proteins. Specifically, in this study, heterocyclic compounds with different chemical characteristics were examined to highlight the possibility of interaction with the spike protein and the disruption of the interaction between ACE2 and the spike protein. Our results showed that these compounds interacted with the spike protein and interposed in the interaction zone with ACE2. Although further studies are needed, this work points to these heterocyclic push-pull compounds as possible agents capable of interacting with the spike protein, with the potential for the inhibition of spike protein-ACE2 binding.

Causal effects of COVID-19 on cancer risk: A Mendelian randomization study

In contemporary literature, little attention has been paid to the association between coronavirus disease-2019 (COVID-19) and cancer risk. We performed the Mendelian randomization (MR) to investigate the causal associations between the three types of COVID-19 exposures (critically ill COVID-19, hospitalized COVID-19, and respiratory syndrome coronavirus 2 (SARS-CoV-2) infection) and 33 different types of cancers of the European population. The results of the inverse-variance-weighted model indicated that genetic liabilities to critically ill COVID-19 had suggestive causal associations with the increased risk for HER2-positive breast cancer (odds ratio [OR] = 1.0924; p-value = 0.0116), esophageal cancer (OR = 1.0004; p-value = 0.0226), colorectal cancer (OR = 1.0010; p-value = 0.0242), stomach cancer (OR = 1.2394; p-value = 0.0331), and colon cancer (OR = 1.0006; p-value = 0.0453). The genetic liabilities to hospitalized COVID-19 had suggestive causal associations with the increased risk for HER2-positive breast cancer (OR = 1.1096; p-value = 0.0458), esophageal cancer (OR = 1.0005; p-value = 0.0440) as well as stomach cancer (OR = 1.3043; p-value = 0.0476). The genetic liabilities to SARS-CoV-2 infection had suggestive causal associations with the increased risk for stomach cancer (OR = 2.8563; p-value = 0.0019) but with the decreasing risk for head and neck cancer (OR = 0.9986, p-value = 0.0426). The causal associations of the above combinations were robust through the test of heterogeneity and pleiotropy. Together, our study indicated that COVID-19 had causal effects on cancer risk.

Genetic analysis of ACE2 peptidase domain in SARS-CoV-2-positive and SARS-CoV-2-negative individuals from Pakistan

BACKGROUND

The outbreak of coronavirus disease 2019 (COVID-19) has emerged as a serious public health emergency of global concern. Angiotensin converting enzyme 2 (ACE2) peptidase domain is important for the cellular entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Germline variants in ACE2 peptidase domain may influence the susceptibility for SARS-CoV-2 infection and disease severity in the host population. ACE2 genetic analysis among Caucasians showed inconclusive results. This is the first Asian study investigating the contribution of ACE2 germline variants to SARS-CoV-2 infection in Pakistani population.

METHODS

In total, 442 individuals, including SARS-CoV-2-positive (n = 225) and SARS-CoV-2-negative (n = 217) were screened for germline variants in ACE2 peptidase domain (exons 2, 3, 9, and 10) using high resolution melting and denaturing high-performance liquid chromatography analyses followed by DNA sequencing of variant fragments. The identified variant was analyzed by in silico tools for potential effect on ACE2 protein.

RESULTS

A missense variant, p.Lys26Arg, was identified in one SARS-CoV-2-positive (1/225; 0.4%) and three SARS-CoV-2-negative (3/217; 1.4%) individuals. No significant difference in the minor allele frequency of this variant was found among SARS-CoV-2-positive and SARS-CoV-2-negative individuals (1/313; 0.3% versus 3/328; 0.9%; P = 0.624), respectively. The SARS-CoV-2-positive patient carrying p.Lys26Arg showed mild COVID-19 disease symptoms. It was predicted as benign variant by in silico tool. No variant was detected in ACE2 residues important for binding of SARS-CoV-2 spike protein.

CONCLUSION

The p.Lys26Arg variant may have no association with SARS-CoV-2 susceptibility in Pakistani population. Whole ACE2 gene screening is warranted to clarify its role in SARS-CoV-2 infection.

miRNAs as a Potential Biomarker in the COVID-19 Infection and Complications Course, Severity, and Outcome

During the last three years, since the emergence of the COVID-19 pandemic, a significant number of scientific publications have focused on resolving susceptibility to the infection, as well as the course of the disease and potential long-term complications. COVID-19 is widely considered as a multisystem disease and a variety of socioeconomic, medical, and genetic/epigenetic factors may contribute to the disease severity and outcome. Furthermore, the SARS-COV-2 infection may trigger pathological processes and accelerate underlying conditions to clinical entities. The development of specific and sensitive biomarkers that are easy to obtain will allow for patient stratification, prevention, prognosis, and more individualized treatments for COVID-19. miRNAs are proposed as promising biomarkers for different aspects of COVID-19 disease (susceptibility, severity, complication course, outcome, and therapeutic possibilities). This review summarizes the most relevant findings concerning miRNA involvement in COVID-19 pathology. Additionally, the role of miRNAs in wide range of complications due to accompanied and/or underlying health conditions is discussed. The importance of understanding the functional relationships between different conditions, such as pregnancy, obesity, or neurological diseases, with COVID-19 is also highlighted.

Expression of SARS-CoV-2 receptor angiotensin-converting enzyme 2 by activating protein-1 in human mast cells

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection activates mast cells and induces a cytokine storm, leading to severe Coronavirus disease in 2019 (COVID-19). SARS-CoV-2 employs angiotensin-converting enzyme 2 (ACE2) for cell entry. In the present study, the expression of ACE2 and its mechanism in activated mast cells were studied utilizing the human mast cell line, HMC-1 cells and it was elucidated whether dexamethasone used as a treatment for COVID-19 could regulate ACE2 expression. Here we documented for the first time that levels of ACE2 were increased by stimulation of phorbol 12-myristate 13-acetate and A23187 (PMACI) in HMC-1 cells. Increased levels of ACE2 were significantly diminished by treatment with Wortmannin, SP600125, SB203580, PD98059, or SR11302. The expression of ACE2 was most significantly reduced by the activating protein (AP)-1 inhibitor SR11302. PMACI stimulation enhanced the expression of the transcription factor AP-1 for ACE2. In addition, levels of transmembrane protease/serine subfamily member 2 (TMPRSS2) and tryptase were increased in PMACI-stimulated HMC-1 cells. However, dexamethasone significantly lowered levels of ACE2, TMPRSS2, and tryptase generated by PMACI. Treatment with dexamethasone also reduced activation of signaling molecules linked to ACE2 expression. According to these findings, levels of ACE2 were up-regulated through activation of AP-1 in mast cells, suggesting that suppressing ACE2 levels in mast cells would be a therapeutic approach to lessen the harm caused by COVID-19.

Effects of Usnic Acid to Prevent Infections by Creating a Protective Barrier in an In Vitro Study

Nasal sprays are medical devices useful for preventing infection and the subsequent spread of airborne pathogens. The effectiveness of these devices depends on the activity of chosen compounds which can create a physical barrier against viral uptake as well as incorporate different substances with antiviral activity. Among antiviral compounds, UA, a dibenzofuran derived from lichens, has the mechanical ability to modify its structure by creating a branch capable of forming a protective barrier. The mechanical ability of UA to protect cells from virus infection was investigated by analyzing the branching capacity of UA, and then the protection mechanism in an in vitro model was also studied. As expected, UA at 37 °C was able to create a barrier confirming its ramification property. At the same time, UA was able to block the infection of Vero E6 and HNEpC cells by interfering with a biological interaction between cells and viruses as revealed also by the UA quantification. Therefore, UA can block virus activity through a mechanical barrier effect without altering the physiological nasal homeostasis. The findings of this research could be of great relevance in view of the growing alarm regarding the spread of airborne viral diseases.

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.

Effect of SARS-CoV-2 infection in pregnancy on CD147, ACE2 and HLA-G expression

INTRODUCTION

Recent studies reported a differential expression of both ACE2 and CD147 in pregnant women associated to SARS-CoV-2 placental infection. The aim of this study is to further investigate the placental SARS-CoV-2 infection and the potential effect on protein expression (ACE2, CD147, HLA-G and CD56).

METHODS

The study was on three subgroups: i) 18 subjects positive for SARS-CoV-2 swab at delivery; ii) 9 subjects that had a positive SARS-CoV-2 swab during pregnancy but resulted negative at delivery; iii) 11 control subjects with physiological pregnancy and with no previous or concomitant SARS-CoV-2 swab positivity. None of the subjects were vaccinated for SARS-CoV-2 infection. The placenta samples were analyzed for SARS-CoV-2 NP (Nucleocapsid protein) positivity and the expression of ACE2, CD147, HLA-G and CD56.

RESULTS

We observed a higher percentage of SARS-CoV-2 NP positive placenta samples in the group of SARS-CoV-2 PCR positive at delivery in comparison with SARS-CoV-2 PCR negative at delivery. The localization of SARS-CoV-2 NP positivity in placenta samples was mainly in syncytiotrophoblast (ST) of SARS-CoV-2 PCR positive at delivery group and in extra-villous trophoblast (EVT) of SARS-CoV-2 PCR negative at delivery group. CD147, HLA-G positivity was higher in ST of SARS-CoV-2 PCR positive at delivery group, while CD56-expressing immune cells were decreased in comparison with control subjects.

DISCUSSION

We confirmed the ability of SARS-CoV-2 to infect placenta tissues. The simultaneous SARS-CoV-2 swab positivity at delivery and the positivity of the placenta tissue for SARS-CoV-2 NP seems to create an environment that modifies the expression of specific molecules, as CD147 and HLA-G. These data suggest a possible impact of SARS-CoV-2 infection during pregnancy, that might be worthy to be monitored also in vaccinated subjects.

Relevance of HLA-DP/DQ and INF-λ4 Polymorphisms to COVID-19 Outcomes

Background: Single nucleotide polymorphisms provide information on individuals' potential reactions to environmental factors, infections, diseases, as well as various therapies. A study on SNPs that influence SARS-CoV-2 susceptibility and severity may provide a predictive tool for COVID-19 outcomes and improve the customized coronavirus treatment. Aim: To evaluate the role of human leukocyte antigens DP/DQ and IFNλ4 polymorphisms on COVID-19 outcomes among Egyptian patients. Participants and Methods: The study involved 80 patients with severe COVID-19, 80 patients with mild COVID-19, and 80 non-infected healthy volunteers. Genotyping and allelic discrimination of HLA-DPrs3077 (G/A), HLA-DQrs7453920 (A/G), and IFNλ4 rs73555604 (C/T) SNPs were performed using real-time PCR. Results: Ages were 47.9 ± 8, 44.1 ± 12.1, and 45.8 ± 10 years in severe, mild and non-infected persons. There was a statistically significant association between severe COVID-19 and male gender (p = 0.002). A statistically significant increase in the frequency of HLA-DPrs3077G, HLA-DQrs7453920A, and IFNλ4rs73555604C alleles among severe COVID-19 patients when compared with other groups (p < 0.001). Coexistence of these alleles in the same individual increases the susceptibility to severe COVID-19 by many folds (p < 0.001). Univariate and multivariate logistic regression analysis for the studied parameters showed that old age, male gender, non-vaccination, HLA-DQ rs7453920AG+AA, HLA-DPrs3077GA+GG, and IFNλ4rs73555604CT+CC genotypes are independent risk factors for severe COVID-19 among Egyptian patients. Conclusion: HLA-DQ rs7453920A, HLA-DPrs3077G, and IFNλ4rs73555604C alleles could be used as markers of COVID-19 severity.

S Protein, ACE2 and Host Cell Proteases in SARS-CoV-2 Cell Entry and Infectivity; Is Soluble ACE2 a Two Blade Sword? A Narrative Review

Since the spread of the deadly virus SARS-CoV-2 in late 2019, researchers have restlessly sought to unravel how the virus enters the host cells. Some proteins on each side of the interaction between the virus and the host cells are involved as the major contributors to this process: (1) the nano-machine spike protein on behalf of the virus, (2) angiotensin converting enzyme II, the mono-carboxypeptidase and the key component of renin angiotensin system on behalf of the host cell, (3) some host proteases and proteins exploited by SARS-CoV-2. In this review, the complex process of SARS-CoV-2 entrance into the host cells with the contribution of the involved host proteins as well as the sequential conformational changes in the spike protein tending to increase the probability of complexification of the latter with angiotensin converting enzyme II, the receptor of the virus on the host cells, are discussed. Moreover, the release of the catalytic ectodomain of angiotensin converting enzyme II as its soluble form in the extracellular space and its positive or negative impact on the infectivity of the virus are considered.

An Automated Strategy to Handle Antigenic Variability in Immunisation Protocols, Part I: Nanopore Sequencing of Infectious Agent Variants

Infectious agents often challenge therapeutics, from antibiotics resistance to antigenic variability affecting inoculation measures. Over the last decades, genome sequencing arose as an important ally to address such challenges. In bacterial infection, whole-genome-sequencing (WGS) supports tracking pathogenic alterations affecting the human microbiome. In viral infection, the analysis of the relevant sequence of nucleotides helps with determining historical variants of a virus and elucidates details about infection clusters and their distribution. Additionally, genome sequencing is now an important step in inoculation protocols, isolating target genes to design more robust immunisation assays. Ultimately, genetic engineering has empowered repurposing at scale, allowing long-lasting repeating clinical trials to be automated within a much shorter time-frame, by adjusting existing protocols. This is particularly important during sanitary emergencies as the ones caused by the 2014 West African Ebola outbreak, the Zika virus rapid spread in both South and North America in 2015, followed by Asia in 2016, and the pandemic caused by the SARS-CoV-2, which has infected more than 187 million people and caused more than 4 million deaths, worldwide, as per July 2021 statistics. In this scenery, this chapter presents a novel fully automated strategy to handle antigenic variability in immunisation protocols. The methodology comprises of two major steps (1) nanopore sequencing of infectious agent variants - the focus is on the SARS-CoV-2 and its variants; followed by (2) mRNA vector design for immunotherapy. This chapter presents the nanopore sequencing step and Chapter 17 introduces a protocol for mRNA vector design.

Progress in salivary glands: Endocrine glands with immune functions

The production and secretion of saliva is an essential function of the salivary glands. Saliva is a complicated liquid with different functions, including moistening, digestion, mineralization, lubrication, and mucosal protection. This review focuses on the mechanism and neural regulation of salivary secretion, and saliva is secreted in response to various stimuli, including odor, taste, vision, and mastication. The chemical and physical properties of saliva change dynamically during physiological and pathophysiological processes. Moreover, the central nervous system modulates salivary secretion and function via various neurotransmitters and neuroreceptors. Smell, vision, and taste have been investigated for the connection between salivation and brain function. The immune and endocrine functions of the salivary glands have been explored recently. Salivary glands play an essential role in innate and adaptive immunity and protection. Various immune cells such as B cells, T cells, macrophages, and dendritic cells, as well as immunoglobins like IgA and IgG have been found in salivary glands. Evidence supports the synthesis of corticosterone, testosterone, and melatonin in salivary glands. Saliva contains many potential biomarkers derived from epithelial cells, gingival crevicular fluid, and serum. High level of matrix metalloproteinases and cytokines are potential markers for oral carcinoma, infectious disease in the oral cavity, and systemic disease. Further research is required to monitor and predict potential salivary biomarkers for health and disease in clinical practice and precision medicine.

Risk of New-Onset Liver Injuries Due to COVID-19 in Preexisting Hepatic Conditions-Review of the Literature

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted the world and caused the 2019 coronavirus disease (COVID-19) pandemic. The clinical manifestations of the virus can vary from patient to patient, depending on their respective immune system and comorbidities. SARS-CoV-2 can affect patients through two mechanisms: directly by targeting specific receptors or by systemic mechanisms. We reviewed data in the latest literature in order to discuss and determine the risk of new-onset liver injuries due to COVID-19 in preexisting hepatic conditions. The particular expression of angiotensin-converting enzyme 2 (ACE2) receptors is an additional risk factor for patients with liver disease. COVID-19 causes more severe forms in patients with non-alcoholic fatty liver disease (NAFLD), increases the risk of cirrhosis decompensation, and doubles the mortality for these patients. The coinfection SARS-CoV-2-viral hepatitis B or C might have different outcomes depending on the stage of the liver disease. Furthermore, the immunosuppressant treatment administered for COVID-19 might reactivate the hepatic virus. The high affinity of SARS-CoV-2 spike proteins for cholangiocytes results in a particular type of secondary sclerosing cholangitis. The impact of COVID-19 infection on chronic liver disease patients is significant, especially in cirrhosis, influencing the prognosis and outcome of these patients.

Toxoplasmosis and symptoms severity in patients with COVID-19 in referral centers in Northern Iran

Toxoplasmosis has been categorized as one of the long-lasting protozoan parasitic infections. It affects almost one-third of the world's population. In recent years, several documented studies have elucidated that infected individuals have a remarkably higher incidence of distinct health problems and show various adverse effects. In the PCR-positive COVID-19 patients in Gonbad-e-Kavus, Kalaleh, and Minoodasht counties in the northern part of Iran from June 2021 to December 2021, we sought to investigate any potential relationships between the severity of COVID-19 symptoms and acute and latent toxoplasmosis caused by Toxoplasma gondii (T. gondii). Whole blood samples of 161 COVID-19 patients with positive PCR. The samples were centrifuged to separate serum and screened for two important antibodies against T. gondii (IgM and IgG) by using ELISA kits for human anti-T. gondii IgM and IgG. Anti-T. gondii IgM and IgG antibodies were detected in 8/161 (5.0%) and 42/161 (26.1%) COVID-19 patients, respectively. No significant relationships were found between Toxoplasma IgM and IgG results with clinical signs, age, sex, contact with animals, comorbidities, and also the mortality rate of people with COVID-19. These findings showed that acute and latent toxoplasmosis infections are common among patients with COVID-19; however, no significant associations were found between toxoplasma infections and the symptoms of COVID-19. Therefore, toxoplasmosis is not considered a risk factor for COVID-19.

The vital role of animal, marine, and microbial natural products against COVID-19

CONTEXT

Since the outbreak of SARS-CoV-2, researchers have been working on finding ways to prevent viral entry and pathogenesis. Drug development from naturally-sourced pharmacological constituents may be a fruitful approach to COVID-19 therapy.

OBJECTIVE

Most of the published literature has focussed on medicinal plants, while less attention has been given to biodiverse sources such as animal, marine, and microbial products. This review focuses on highlighting natural products and their derivatives that have been evaluated for antiviral, anti-inflammatory, and immunomodulatory properties.

METHODS

We searched electronic databases such as PubMed, Scopus, Science Direct and Springer Link to gather raw data from publications up to March 2021, using terms such as 'natural products', marine, micro-organism, and animal, COVID-19. We extracted a number of documented clinical trials of products that were tested in silico, in vitro, and in vivo which paid specific attention to chemical profiles and mechanisms of action.

RESULTS

Various classes of flavonoids, 2 polyphenols, peptides and tannins were found, which exhibit inhibitory properties against viral and host proteins, including 3CLpro, PLpro, S, hACE2, and NF-κB, many of which are in different phases of clinical trials.

DISCUSSION AND CONCLUSIONS

The synergistic effects of logical combinations with different mechanisms of action emphasizes their value in COVID19 management, such as iota carrageenan nasal spray, ermectin oral drops, omega-3 supplementation, and a quadruple treatment of zinc, quercetin, bromelain, and vitamin C. Though in vivo efficacy of these compounds has yet to be established, these bioproducts are potentially useful in counteracting the effects of SARS-CoV-2.

Proteolysis and Deficiency of α1-Proteinase Inhibitor in SARS-CoV-2 Infection

The SARS-CoV-2 pandemic had stimulated the emergence of numerous publications on the α1-proteinase inhibitor (α1-PI, α1-antitrypsin), especially when it was found that the regions of high mortality corresponded to the regions with deficient α1-PI alleles. By analogy with the data obtained in the last century, when the first cause of the genetic deficiency of α1-antitrypsin leading to elastase activation in pulmonary emphysema was proven, it can be supposed that proteolysis hyperactivation in COVID-19 may be associated with the impaired functions of α1-PI. The purpose of this review was to systematize the scientific data and critical directions for translational studies on the role of α1-PI in SARS-CoV-2-induced proteolysis hyperactivation as a diagnostic marker and a therapeutic target. This review describes the proteinase-dependent stages of viral infection: the reception and penetration of the virus into a cell and the imbalance of the plasma aldosterone-angiotensin-renin, kinin, and blood clotting systems. The role of ACE2, TMPRSS, ADAM17, furin, cathepsins, trypsin- and elastase-like serine proteinases in the virus tropism, the activation of proteolytic cascades in blood, and the COVID-19-dependent complications is considered. The scientific reports on α1-PI involvement in the SARS-CoV-2-induced inflammation, the relationship with the severity of infection and comorbidities were analyzed. Particular attention is paid to the acquired α1-PI deficiency in assessing the state of patients with proteolysis overactivation and chronic non-inflammatory diseases, which are accompanied by the risk factors for comorbidity progression and the long-term consequences of COVID-19. Essential data on the search and application of protease inhibitor drugs in the therapy for bronchopulmonary and cardiovascular pathologies were analyzed. The evidence of antiviral, anti-inflammatory, anticoagulant, and anti-apoptotic effects of α1-PI, as well as the prominent data and prospects for its application as a targeted drug in the SARS-CoV-2 acquired pneumonia and related disorders, are presented.

Paxlovid administration in elderly patient with COVID-19 caused by Omicron BA.2.0: A case report

RATIONALE

Paxlovid has shown the potential decreasing the hospitalization rate of mild or moderate coronavirus disease 2019 (COVID-19) and death in few of clinical trials, and is expected to the most promising medicine targeting Severe Acute Respiratory Syndrome Coronavirus 2 (SRAS-COV-2). However, there are no enough evidences to show it effectiveness for all patients with SARS-COV-2, especially among elderly patients and newest Omicron variant.

PATIENT CONCERNS AND DIAGNOSIS

A 79 year's old female patient was admitted to hospital because of the moderate COVID-19 caused by the Omicron variant BA2.0. He presented the initial syndromes including Xerostomia, cough and fever. Chest computed tomography (CT) scanning at admission showed the exudation lesions on lung. The laboratory examination revealed that there are increased C-reactive protein (CRP), Ferritin and erythrocytesedimentationrate (ESR) and decreased white blood cells.

INTERVENTIONS

The oral Paxlovid (Nirmatrelvir/Ritonavir) was administrated on second day after admission.

OUTCOMES

The syndromes of Xerostomia, cough and fever was improved on third day after use of Paxlovid. The levels of CRP, ESR and counts of white blood cells returned the normal after three days of admission. The chest CT scanned on the third and sixth day after Paxlovid used showed the absorption of lesions. The examination of SARS-COVS viral nucleic acid turned negative at fifth day of admission.

LESSONS

As a result, we would consider that Paxlovid is a suitable oral drug for elderly patients with SARS-COV2 even Omicron variant, it's benefit to improve patient's symptom and signs and can prevents COVID-19 with the high-risk factors from severe disease, although it didn't shorten the time for viral nucleic acid to turn negative.

Combined effect of traditional Chinese herbal-based formulations Jing Si herbal tea and Jing Si nasal drop inhibits adhesion and transmission of SARS-CoV2 in diabetic SKH-1 mice

Multiple studies show increased severity of SARS-CoV2-infection in patients with comorbidities such as hypertension and diabetes. In this study, we have prepared two herbal-based formulations, a pleiotropic herbal drink (Jin Si Herbal Tea, JHT) and a nasal drop (Jin Si nasal drop, JND), to provide preventive care against SARS-CoV2 infection. The effect of JHT and JND was determined in SARS-CoV2-S-pseudotyped lentivirus-infected bronchial and colorectal cell lines and in SKH-1 mouse models. For preliminary studies, ACE2 receptor abundant bronchial (Calu-3) and colorectal cells (Caco-2) were used to determine the effect of JHT and JND on the host entry of various variants of SARS-CoV2-S-pseudotyped lentivirus. A series of experiments were performed to understand the infection rate in SKH-1 mice (6 weeks old, n = 9), find the effective dosage of JHT and JND, and determine the combination effect of JHT and JND on the entry and adhesion of various variant SARS-CoV2-S-pseudotyped lentiviruses, which included highly transmissible delta and gamma mutants. Furthermore, the effect of combined JHT and JND was determined on diabetes-induced SKH-1 mice against the comorbidity-associated intense viral entry and accumulation. In addition, the effect of combined JHT and JND administration on viral transmission from infected SKH-1 mice to uninfected cage mate mice was determined. The results showed that both JHT and JND were effective in alleviating the viral entry and accumulation in the thorax and the abdominal area. While JHT showed a dose-dependent decrease in the viral load, JND showed early inhibition of viral entry from day 1 of the infection. Combined administration of 48.66 mg of JHT and 20 µL of JND showed rapid reduction in the viral entry and reduced the viral load (97-99%) in the infected mice within 3 days of treatment. Moreover, 16.22 mg of JHT and 20 µL JND reduced the viral infection in STZ-induced diabetic SKH-1 mice. Interestingly, combined JHT and JND also inhibited viral transmission among cage mates. The results, therefore, showed that combined administration of JHT and JND is a novel and an efficient strategy to potentially prevent SARS-CoV2 infection.

COVID-19 Vaccination in Kidney Transplant Candidates and Recipients

Kidney transplant candidates and kidney transplant recipients (KTRs) are at particular risk of severe complications of COVID-19 disease. In Western countries, mortality in affected hospitalized KTRs ranges between 19% and 50%. COVID-19 vaccination remains the most important measure to prevent the severity of infection in candidates and recipients of kidney transplant. However, the uraemic condition may affect the vaccine-induced immunity in patients with advanced chronic kidney disease (CKD) and in KTRs. Retention of uraemic toxins, dysbiosis, dysmetabolism, and dialysis can diminish the normal response to vaccination, leading to dysfunction of inflammatory and immune cells. In KTRs the efficacy of vaccines may be reduced by the immunosuppressive medications, and more than half of kidney transplant recipients are unable to build an immune response even after four administrations of anti-COVID-19 vaccines. The lack of antibody response leaves these patients at high risk for SARS-CoV-2 infection and severe COVID-19 disease. The aim of the present review is to focus on the main reasons for the impaired immunological response among candidates and kidney transplant recipients and to highlight some of the present options available to solve the problem.

Chemical Constituents, Quantitative Analysis, Anti-SARS-CoV-2 and Antioxidant Activities of Herbal Formula “Ping An Fang Yu Yin”

COVID-19 is a global pandemic infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The herbal formula, Ping An Fang Yu Yin (PAFYY), has been used to prevent respiratory viral infections for many years. This study aims to evaluate the effect of PAFYY on SARS-CoV-2 infection, oxidative stress, and inflammation via in vitro, investigate the chemical composition by full constituent quantitative analysis, and verify its anti-viral potential against SARS-CoV-2 using in silico. In this study, a total of eleven compounds, twenty amino acids, saccharide compositions, and trace elements were found and quantitatively determined by chromatographic techniques. PAFYY displayed free radical scavenging activity (DPPH, SC50: 1.24 ± 0.09 mg/mL), SOD activity (68.71 ± 1.28%), inhibition of lipoxygenase activity (75.96 ± 7.64 mg/mL) and interfered the interaction of SARS-CoV-2 spike protein and angiotensin-converting enzyme 2 (48.04 ± 3.18%). Furthermore, in-silico analysis results supported that liquiritin, 3,5-dicaffeoylquinic acid, and luteolin-7-O-glucoside with the highest affinity between SARS-CoV-2 RBD and human angiotensin-converting enzyme II (hACE2) receptor. Our findings suggest that PAFYY has the potential for anti-SARS-CoV-2 infection, anti-oxidation stress, and anti-inflammation, and may be used as supplements for amelioration or prevention of COVID-19 symptoms, as well as the representative compounds can be used for quality control of PAFYY in the future.