Nicotine and the nicotinic cholinergic system in COVID-19

The association between tobacco use and COVID-19 diagnoses in three Nordic countries: a pooled analysis

Previous research has suggested an unexpected negative association between smoking and susceptibility to COVID-19. This study, drawing on population-based data from three Nordic countries-Sweden, Norway, and Finland-aims to investigate this association further, capitalizing on diversity introduced by different containment measures. The objective of this research was to examine the association between cigarette smoking and snus (smokeless tobacco) use and the risk of confirmed COVID-19 infection. A pooled analysis integrating original data from 547,685 participants across three countries. We used a multiple imputation approach based on conditional probabilities to impute the systematically missing covariates. The associations between tobacco use and COVID-19 infection were assessed, controlling for potential confounding factors. Current cigarette smokers had a lower risk of a confirmed COVID-19 case, whereas there was an increased risk among snus users. Our sensitivity analysis confirmed that the associations between tobacco use and COVID-19 infection risk are robust, remaining consistent regardless of whether covariate imputation was applied. Findings support a negative association between smoking and SARS-CoV-2 infection, but not the hypothesis that nicotine may be protective against the risk of contracting SARS-CoV-2 infection.

Tobacco, nicotine, and cannabis use and exposure in an Australian Indigenous population during pregnancy: A protocol to measure parental and foetal exposure and outcomes

BACKGROUND

The Australian National Perinatal Data Collection collates all live and stillbirths from States and Territories in Australia. In that database, maternal cigarette smoking is noted twice (smoking <20 weeks gestation; smoking >20 weeks gestation). Cannabis use and other forms of nicotine use, for example vaping and nicotine replacement therapy, are nor reported. The 2021 report shows the rate of smoking for Australian Indigenous mothers was 42% compared with 11% for Australian non-Indigenous mothers. Evidence shows that Indigenous babies exposed to maternal smoking have a higher rate of adverse outcomes compared to non-Indigenous babies exposed to maternal smoking (S1 File).

OBJECTIVES

The reasons for the differences in health outcome between Indigenous and non-Indigenous pregnancies exposed to tobacco and nicotine is unknown but will be explored in this project through a number of activities. Firstly, the patterns of parental and household tobacco, nicotine and cannabis use and exposure will be mapped during pregnancy. Secondly, a range of biological samples will be collected to enable the first determination of Australian Indigenous people's nicotine and cannabis metabolism during pregnancy; this assessment will be informed by pharmacogenomic analysis. Thirdly, the pharmacokinetic and pharmacogenomic findings will be considered against maternal, placental, foetal and neonatal outcomes. Lastly, an assessment of population health literacy and risk perception related to tobacco, nicotine and cannabis products peri-pregnancy will be undertaken.

METHODS

This is a community-driven, co-designed, prospective, mixed-method observational study with regional Queensland parents expecting an Australian Indigenous baby and their close house-hold contacts during the peri-gestational period. The research utilises a multi-pronged and multi-disciplinary approach to explore interlinked objectives.

RESULTS

A sample of 80 mothers expecting an Australian Indigenous baby will be recruited. This sample size will allow estimation of at least 90% sensitivity and specificity for the screening tool which maps the patterns of tobacco and nicotine use and exposure versus urinary cotinine with 95% CI within ±7% of the point estimate. The sample size required for other aspects of the research is less (pharmacokinetic and genomic n = 50, and the placental aspects n = 40), however from all 80 mothers, all samples will be collected.

CONCLUSIONS

Results will be reported using the STROBE guidelines for observational studies.

FORWARD

We acknowledge the Traditional Custodians, the Butchulla people, of the lands and waters upon which this research is conducted. We acknowledge their continuing connections to country and pay our respects to Elders past, present and emerging. Notation: In this document, the terms Aboriginal and Torres Strait Islander and Indigenous are used interchangeably for Australia's First Nations People. No disrespect is intended, and we acknowledge the rich cultural diversity of the groups of peoples that are the Traditional Custodians of the land with which they identify and with whom they share a connection and ancestry.

Nicotinic Acetylcholine Receptors in Glial Cells as Molecular Target for Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by resting tremor, bradykinesia, rigidity, and postural instability that also includes non-motor symptoms such as mood dysregulation. Dopamine (DA) is the primary neurotransmitter involved in this disease, but cholinergic imbalance has also been implicated. Current intervention in PD is focused on replenishing central DA, which provides remarkable temporary symptomatic relief but does not address neuronal loss and the progression of the disease. It has been well established that neuronal nicotinic cholinergic receptors (nAChRs) can regulate DA release and that nicotine itself may have neuroprotective effects. Recent studies identified nAChRs in nonneuronal cell types, including glial cells, where they may regulate inflammatory responses. Given the crucial role of neuroinflammation in dopaminergic degeneration and the involvement of microglia and astrocytes in this response, glial nAChRs may provide a novel therapeutic target in the prevention and/or treatment of PD. In this review, following a brief discussion of PD, we focus on the role of glial cells and, specifically, their nAChRs in PD pathology and/or treatment.

Regulation of Inflammation by IRAK-M Pathway Can Be Associated with nAchRalpha7 Activation and COVID-19

In spite of the vaccine development and its importance, the SARS-CoV-2 pandemic is still impacting the world. It is known that the COVID-19 severity is related to the cytokine storm phenomenon, being inflammation a common disease feature. The nicotinic cholinergic system has been widely associated with COVID-19 since it plays a protective role in inflammation via nicotinic receptor alpha 7 (nAchRalpha7). In addition, SARS-CoV-2 spike protein (Spro) subunits can interact with nAchRalpha7. Moreover, Spro causes toll-like receptor (TLR) activation, leading to pro- and anti-inflammatory pathways. The increase and maturation of the IL-1 receptor-associated kinase (IRAK) family are mediated by activation of membrane receptors, such as TLRs. IRAK-M, a member of this family, is responsible for negatively regulating the activity of other active IRAKs. In addition, IRAK-M can regulate microglia phenotype by specific protein expression. Furthermore, there exists an antagonist influence of SARS-CoV-2 Spro and the cholinergic system action on the IRAK-M pathway and microglia phenotype. We discuss the overexpression and suppression of IRAK-M in inflammatory cell response to inflammation in SARS-CoV-2 infection when the cholinergic system is constantly activated via nAchRalpha7.

COVID-19 and Alzheimer's Disease Share Common Neurological and Ophthalmological Manifestations: A Bidirectional Risk in the Post-Pandemic Future

A growing body of evidence indicates that a neuropathological cross-talk takes place between the coronavirus disease 2019 (COVID-19) -the pandemic severe pneumonia that has had a tremendous impact on the global economy and health since three years after its outbreak in December 2019- and Alzheimer's Disease (AD), the leading cause of dementia among human beings, reaching 139 million by the year 2050. Even though COVID-19 is a primary respiratory disease, its causative agent, the so-called Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), is also endowed with high neuro-invasive potential (Neurocovid). The neurological complications of COVID-19, resulting from the direct viral entry into the Central Nervous System (CNS) and/or indirect systemic inflammation and dysregulated activation of immune response, encompass memory decline and anosmia which are typically associated with AD symptomatology. In addition, patients diagnosed with AD are more vulnerable to SARS-CoV-2 infection and are inclined to more severe clinical outcomes. In the present review, we better elucidate the intimate connection between COVID-19 and AD by summarizing the involved risk factors/targets and the underlying biological mechanisms shared by these two disorders with a particular focus on the Angiotensin-Converting Enzyme 2 (ACE2) receptor, APOlipoprotein E (APOE), aging, neuroinflammation and cellular pathways associated with the Amyloid Precursor Protein (APP)/Amyloid beta (Aβ) and tau neuropathologies. Finally, the involvement of ophthalmological manifestations, including vitreo-retinal abnormalities and visual deficits, in both COVID-19 and AD are also discussed. Understanding the common physiopathological aspects linking COVID-19 and AD will pave the way to novel management and diagnostic/therapeutic approaches to cope with them in the post-pandemic future.

Nicotine plays a protective role in rats with induced viral pneumonia with polyinosinic-polycytidylic acid through α7nAChR

Objective

To study the effect of nicotine in rat model of pneumonia induced by polyinosinic-polycytidylic acid [Poly (I:C)] and explore the underlying mechanism.

Methods

Twenty-four healthy adult male Sprague-Dawley (SD) rats (200-250 g) were randomly divided into normal saline control group (NS group); Poly (I:C) group; nicotine group (NIC group); and α7 nicotinic acetylcholine receptor (α7nAChR) antagonist group (α-BGT group) (n = 6 each). Rats in the Poly (I: C), NIC, and α-BGT groups were administered 1.5 mg/mL 100 μL Poly (I:C) intranasally to establish pneumonia model. In α-BGT group, 1 μg/kg α-bungarotoxin (α-BGT) was intraperitoneally injected 45 min before intranasal Poly (I:C), and 400 μg/kg nicotine was intraperitoneally injected 15 min after α-BGT injection. The NIC group received an equal volume of NS in place of α-BGT while the other treatments were same. The Poly (I:C) group received equal volume of NS in place of nicotine while the other treatments were same as in NIC group. In the NS group, only NS was administered at all three time points. PaCO2, PaO2, and PaO2/FiO2 levels were determined 24 h after administration of Poly (I:C). After euthanization, rat lung tissues were extracted for pathological examination, and wet weight/dry weight (W/D ratio) was determined. Expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and interferon (IFN)-γ in lung tissue was determined by ELISA. q-PCR was used to detect nuclear factor kappa-B P65 (NF-κBP65).

Results

Compared with NS group, Poly (I:C) and α-BGT groups showed significantly increased W/D ratio, PaCO2, TNF-α, IL-6, IL-1β, and IFN-γ content, NF-κB P65 expression, and reduced PaO2 and PaO2/FiO2 (p < 0.05), along with obvious signs of pathological injury. Nicotine pre-treatment reduced W/D ratio, PaCO2, proinflammatory cytokines, NF-κBP65 expression, and increased PaO2 and PaO2/FiO2 levels. The above effects were negated in α-BGT group.

Conclusion

Pre-administration of nicotine improved Poly (I:C)-induced pneumonia by activating the cholinergic anti-inflammatory pathway.

COVID-19 and tobacco products use among US adults, 2021 National Health Interview Survey

Background

Smoking and vaping are linked to lung inflammation and lowered immune response.

Objective

Examine the prevalence of coronavirus disease 2019 (COVID-19) cases, testing, symptoms, and vaccine uptake, and associations with tobacco product use.

Methods

Data came from the 2021 National Health Interview Survey. The 2021 Sample Adult component included 29,482 participants with a response rate of 50.9%. We investigated COVID-19-related outcomes by tobacco product use status and reported national estimates. Multivariable regression models were performed accounting for demographics (e.g., age, sex, poverty level), serious psychological distress, disability, and chronic health conditions.

Results

In our regression analyses, odds of self-reported COVID-19 infection were significantly lower for combustible tobacco product users (vs. nonusers; adjusted odds ratio [AOR = 0.73; 95% confidence interval [CI] = 0.62-0.85]). Combustible tobacco users also were less likely to report ever testing for COVID-19 (AOR = 0.88; 95% CI = 0.79-0.98), ever testing positive for COVID-19 (AOR = 0.66; 95% CI = 0.56-0.77), and ever receiving COVID-19 vaccine (AOR = 0.58; 95% CI = 0.51-0.66) compared with their nonuser peers. Compared to nonusers, users of any type of tobacco who contracted COVID-19 had higher odds of losing smell (AOR = 1.36; 95%CI = 1.04-1.77), which was more pronounced among exclusive e-cigarette users. The odds of receiving vaccine were lower for all current exclusive tobacco product users compared to nonusers (AORs = 0.40 to 0.70).

Conclusions

Continued monitoring of tobacco product use and its association with respiratory diseases such as COVID-19 is crucial to inform public health policies and programs. In addition, efforts to promote vaccination, especially among tobacco product users, are warranted.

COVID-19: seroprevalence and adherence to preventive measures in Arkhangelsk, Northwest Russia

BACKGROUND

The published estimates of SARS-CoV-2 seroprevalence in Russia are few. The study aimed to assess the SARS-CoV-2 seroprevalence in Arkhangelsk (Northwest Russia), in a year after the start of the pandemic, to evaluate the population adherence to non-pharmaceutical interventions (NPIs), and to investigate characteristics associated with COVID-19 seropositive status.

METHODS

We conducted a SARS-CoV-2 seroprevalence study between 24 February and 30 June 2021 involving 1332 adults aged 40-74 years. Logistic regression models were fit to identify factors associated with seropositive status and with adherence to NPIs.

RESULTS

Less than half (48.9%) of study participants adhered all recommended NPIs. Male sex (odds ratio [OR] 1.7, 95% confidence intervals [CI] 1.3; 2.3), regular employment (OR 1.8, 95% CI 1.3; 2.5) and low confidence in the efficiency of the NPIs (OR 1.9, 95% CI 1.5; 2.5) were associated with low adherence to internationally recommended NPIs. The SARS-CoV-2 seroprevalence rate was 65.1% (95% CI: 62.5; 67.6) and increased to 73.0% (95% CI: 67.1; 85.7) after adjustment for test performance. Regular employment (OR 2.0, 95% CI 1.5; 2.8) and current smoking (OR 0.4, 95% CI 0.2; 0.5) were associated with being seropositive due to the infection.

CONCLUSIONS

Two third of the study population were seropositive in a year after the onset of the pandemic in Arkhangelsk. Individuals with infection-acquired immunity were more likely to have regular work and less likely to be smokers. The adherence to NPIs was not found associated with getting the virus during the first year of the pandemic.

Cholinergic dysfunction in COVID-19: frantic search and hoping for the best

A novel coronavirus known as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a potential cause of acute respiratory infection called coronavirus disease 2019 (COVID-19). The binding of SARS-CoV-2 with angiotensin-converting enzyme 2 (ACE2) induces a series of inflammatory cellular events with cytopathic effects leading to cell injury and hyperinflammation. Severe SARS-CoV-2 infection may lead to dysautonomia and sympathetic storm due to dysfunction of the autonomic nervous system (ANS). Therefore, this review aimed to elucidate the critical role of the cholinergic system (CS) in SARS-CoV-2 infection. The CS forms a multi-faceted network performing diverse functions in the body due to its distribution in the neuronal and non-neuronal cells. Acetylcholine (ACh) acts on two main types of receptors which are nicotinic receptors (NRs) and muscarinic receptors (MRs). NRs induce T cell anergy with impairment of antigen-mediated signal transduction. Nicotine through activation of T cell NRs inhibits the expression and release of the pro-inflammatory cytokines. NRs play important anti-inflammatory effects while MRs promote inflammation by inducing the release of pro-inflammatory cytokines. SARS-CoV-2 infection can affect the morphological and functional stability of CS through the disruption of cholinergic receptors. SARS-CoV-2 spike protein is similar to neurotoxins, which can bind to nicotinic acetylcholine receptors (nAChR) in the ANS and brain. Therefore, cholinergic receptors mainly nAChR and related cholinergic agonists may affect the pathogenesis of SARS-CoV-2 infection. Cholinergic dysfunction in COVID-19 is due to dysregulation of nAChR by SARS-CoV-2 promoting the central sympathetic drive with the development of the sympathetic storm. As well, nAChR activators through interaction with diverse signaling pathways can reduce the risk of inflammatory disorders in COVID-19. In addition, nAChR activators may mitigate endothelial dysfunction (ED), oxidative stress (OS), and associated coagulopathy in COVID-19. Similarly, nAChR activators may improve OS, inflammatory changes, and cytokine storm in COVID-19. Therefore, nAChR activators like varenicline in virtue of its anti-inflammatory and anti-oxidant effects with direct anti-SARS-CoV-2 effect could be effective in the management of COVID-19.

Determination of soluble angiotensin-converting enzyme 2 in saliva samples and its association with nicotine

INTRODUCTION

The Angiotensin-Converting Enzyme 2 (ACE2) is the main receptor of the SARS-CoV-2. There is contradictory evidence on how the exposure to nicotine may module the concentration of soluble ACE2 (sACE2). The aim of this study was to assess the association between nicotine and sACE2 concentrations in saliva samples.

METHODS

Pooled analysis performed with data retrieved from two studies (n = 634 and n = 302). Geometric mean (GM) concentrations of sACE2, both total and relative to the total amount of protein in the sample, were compared according to sociodemographic variables and variables associated to nicotine. Multivariable linear regression models were fitted to explore the associations of sACE2 with nicotine adjusting for sex, age and body mass index. Spearman's rank-correlation coefficients were estimated between the concentrations of nicotine and cotinine, and pack-years, the concentration of relative sACE2 and the isoforms of sACE2.

RESULTS

We observed a significant increase of 0.108‰ and 0.087 ng/μl in the relative and absolute salivary sACE2 GM concentrations, respectively, between the lowest and highest nicotine levels. Similar results were observed for cotinine. These associations did not change in the multivariable linear models. There was a low correlation of nicotine and cotinine concentration with the concentration of relative salivary sACE2 (r_s = 0.153 and r_s = 0.132, respectively), pack-years (r_s = 0.222 and r_s = 0.235, respectively) and with the concentration of isoform 40 KDa (r_s = 0.193 and r_s = 0.140, respectively).

CONCLUSION

Salivary nicotine concentration seems to be limitedly associated with the concentration of sACE2.

Toxin-like Peptides from the Bacterial Cultures Derived from Gut Microbiome Infected by SARS-CoV-2-New Data for a Possible Role in the Long COVID Pattern

It has been 3 years since the beginning of the SARS-CoV-2 outbreak, however it is as yet little known how to care for the acute COVID-19 and long COVID patients. COVID-19 clinical manifestations are of both pulmonary and extra-pulmonary types. Extra-pulmonary ones include extreme tiredness (fatigue), shortness of breath, muscle aches, hyposmia, dysgeusia, and other neurological manifestations. In other autoimmune diseases, such as Parkinson's disease (PD) or Alzheimer's Disease (AD), it is well known that role of acetylcholine is crucial in olfactory dysfunction. We have already observed the presence of toxin-like peptides in plasma, urine, and faecal samples from COVID-19 patients, which are very similar to molecules known to alter acetylcholine signaling. After observing the production of these peptides in bacterial cultures, we have performed additional proteomics analyses to better understand their behavior and reported the extended data from our latest in vitro experiment. It seems that the gut microbiome continues to produce toxin-like peptides also after the decrease of RNA SARS-CoV-2 viral load at molecular tests. These toxicological interactions between the gut/human microbiome bacteria and the virus suggest a new scenario in the study of the clinical symptoms in long COVID and also in acute COVID-19 patients. It is discussed that in the bacteriophage similar behavior, the presence of toxins produced by bacteria continuously after viral aggression can be blocked using an appropriate combination of certain drugs.

Quality of Life and Persistence of Symptoms in Outpatients after Recovery from COVID-19

Background and Objectives: Patients infected with SARS-CoV-2 can have persistent symptoms after acute illness, which affects their quality of life (QoL). Research and data about this topic in Latin American ambulatory patients are scarce. Materials and Methods: We conducted an observational, prospective, transversal, and analytical study. To measure QoL, we used a validated Spanish version of the MOS/RAND 36-Item Short Form Health Survey (SF-36). Results: We included 206 outpatients in the study. A total of 73.3% patients had persistence of one or more symptoms. The most frequent persistent symptoms were fatigue (36.9%), anxiety (26.2%), and headache (24.8%). No statistically significant difference in the SF-36 QoL scores and the frequency of persistent COVID-19 symptoms was found when comparing the ≤5 and >5 months groups, except for myalgia, which was less frequently observed in the >5 months group after COVID-19 (26.2% vs. 14.1%, p < 0.038). Female gender was associated with an increased risk of persistence of symptoms (OR = 2.95, 95% CI 1.56−5.57). Having comorbidities/sequelae attributed to COVID-19 and persistence of COVID-19 symptoms were associated risk factors for poor physical component summary (PCS); on the other hand, female gender, anxiety, and depression were associated with poor mental component summary (MCS). Conclusion: Most outpatients had persistent COVID-19 symptoms after infection. Persistence of symptoms was associated with poor MCS and PCS. It is important to follow-up not only patients discharged from the hospital after SARS-CoV-2 infection, but also those under ambulatory management to provide them with rehabilitation and psychological therapy to improve their QoL.

Old drugs, new tricks: leveraging known compounds to disrupt coronavirus-induced cytokine storm

A major complication in COVID-19 infection consists in the onset of acute respiratory distress fueled by a dysregulation of the host immune network that leads to a run-away cytokine storm. Here, we present an in silico approach that captures the host immune system's complex regulatory dynamics, allowing us to identify and rank candidate drugs and drug pairs that engage with minimal subsets of immune mediators such that their downstream interactions effectively disrupt the signaling cascades driving cytokine storm. Drug-target regulatory interactions are extracted from peer-reviewed literature using automated text-mining for over 5000 compounds associated with COVID-induced cytokine storm and elements of the underlying biology. The targets and mode of action of each compound, as well as combinations of compounds, were scored against their functional alignment with sets of competing model-predicted optimal intervention strategies, as well as the availability of like-acting compounds and known off-target effects. Top-ranking individual compounds identified included a number of known immune suppressors such as calcineurin and mTOR inhibitors as well as compounds less frequently associated for their immune-modulatory effects, including antimicrobials, statins, and cholinergic agonists. Pairwise combinations of drugs targeting distinct biological pathways tended to perform significantly better than single drugs with dexamethasone emerging as a frequent high-ranking companion. While these predicted drug combinations aim to disrupt COVID-induced acute respiratory distress syndrome, the approach itself can be applied more broadly to other diseases and may provide a standard tool for drug discovery initiatives in evaluating alternative targets and repurposing approved drugs.

Cigarettes' use and capabilities-opportunities-motivation-for-behavior model: a multi-country survey of adolescents and young adults

The use of cigarettes among adolescents and young adults (AYA) is an important issue. This study assessed the association between regular and electronic-cigarettes use among AYA and factors of the Capability-Motivation-Opportunity-for-Behavior-change (COM-B) model. A multi-country survey was conducted between August-2020 and January-2021, Data was collected using the Global-Youth-Tobacco-Survey and Generalized-Anxiety-Disorder-7-item-scale. Multi-level logistic-regression-models were used. Use of regular and electronic-cigarettes were dependent variables. The explanatory variables were capability-factors (COVID-19 status, general anxiety), motivation-factors (attitude score) and opportunity-factors (country-level affordability scores, tobacco promotion-bans, and smoke free-zones) controlling for age and sex. Responses of 6,989-participants from 25-countries were used. Those who reported that they were infected with COVID-19 had significantly higher odds of electronic-cigarettes use (AOR = 1.81, P = 0.02). Normal or mild levels of general anxiety and negative attitudes toward smoking were associated with significantly lower odds of using regular-cigarettes (AOR = 0.34, 0.52, and 0.75, P < 0.001) and electronic-cigarettes (AOR = 0.28, 0.45, and 0.78, P < 0.001). Higher affordability-score was associated with lower odds of using electronic-cigarettes (AOR = 0.90, P = 0.004). Country-level-smoking-control policies and regulations need to focus on reducing cigarette affordability. Capability, motivation and opportunity factors of the COM-B model were associated with using regular or electronic cigarettes.

Nicotine patches in patients on mechanical ventilation for severe COVID-19: a randomized, double-blind, placebo-controlled, multicentre trial

Purpose

Epidemiologic studies have documented lower rates of active smokers compared to former or non-smokers in symptomatic patients affected by coronavirus disease 2019 (COVID-19). We assessed the efficacy and safety of nicotine administered by a transdermal patch in critically ill patients with COVID-19 pneumonia.

Methods

In this multicentre, double-blind, placebo-controlled trial conducted in 18 intensive care units in France, we randomly assigned adult patients (non-smokers, non-vapers or who had quit smoking/vaping for at least 12 months) with proven COVID-19 pneumonia receiving invasive mechanical ventilation for up to 72 h to receive transdermal patches containing either nicotine at a daily dose of 14 mg or placebo until 48 h following successful weaning from mechanical ventilation or for a maximum of 30 days, followed by 3-week dose tapering by 3.5 mg per week. Randomization was stratified by centre, non- or former smoker status and Sequential Organ Function Assessment score (< or ≥ 7). The primary outcome was day-28 mortality. Main prespecified secondary outcomes included 60-day mortality, time to successful extubation, days alive and free from mechanical ventilation, renal replacement therapy, vasopressor support or organ failure at day 28.

Results

Between November 6th 2020, and April 2nd 2021, 220 patients were randomized from 18 active recruiting centers. After excluding 2 patients who withdrew consent, 218 patients (152 [70%] men) were included in the analysis: 106 patients to the nicotine group and 112 to the placebo group. Day-28 mortality did not differ between the two groups (30 [28%] of 106 patients in the nicotine group vs 31 [28%] of 112 patients in the placebo group; odds ratio 1.03 [95% confidence interval, CI 0.57–1.87]; p = 0.46). The median number of day-28 ventilator-free days was 0 (IQR 0–14) in the nicotine group and 0 (0–13) in the placebo group (with a difference estimate between the medians of 0 [95% CI -3–7]). Adverse events likely related to nicotine were rare (3%) and similar between the two groups.

Conclusion

In patients having developed severe COVID-19 pneumonia requiring invasive mechanical ventilation, transdermal nicotine did not significantly reduce day-28 mortality. There is no indication to use nicotine in this situation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06721-1.

Inflammatory reflex disruption in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China, in late 2019 and caused coronavirus disease 2019 (COVID-19), which is still a global pandemic. In most infected people, SARS-CoV-2 can only cause moderate symptoms, while in other patients, it leads to severe illness and eventually death. Although the main clinical manifestation of COVID-19 is often seen in the lungs, this disease affects almost all body organs. The excessive and prolonged release of inflammatory cytokines that may occur in COVID-19 patients, known as cytokine storms, stimulates undesired immune responses and can cause various tissues damage. In the current review article, we focus on the potential advantages of the intrinsic cholinergic anti-inflammatory pathway (CAP) as the efferent arm of inflammatory reflex in COVID-19 management. Considering this endogenous protective mechanism against chronic inflammation, we focused on the effects of SARS-CoV-2 in the destruction of this anti-inflammatory system. Several studies indicated the interaction of SARS-CoV-2 with the alpha7 subtype of the nicotinic acetylcholine receptor as the effector molecule of the inflammatory reflex. On the other hand, neurological manifestations have increasingly been identified as significant extrapulmonary manifestations of COVID-19. The rational connection between these findings and COVID-19 pathogenesis may be an important issue in both our understanding and dealing with this disease. COVID-19 is deeply rooted in our daily life and requires an urgent need for the establishment of effective therapeutic options, and all the possible treatments must be considered for the control of such inflammatory conditions.

Nicotine in Inflammatory Diseases: Anti-Inflammatory and Pro-Inflammatory Effects

As an anti-inflammatory alkaloid, nicotine plays dual roles in treating diseases. Here we reviewed the anti-inflammatory and pro-inflammatory effects of nicotine on inflammatory diseases, including inflammatory bowel disease, arthritis, multiple sclerosis, sepsis, endotoxemia, myocarditis, oral/skin/muscle inflammation, etc., mainly concerning the administration methods, different models, therapeutic concentration and duration, and relevant organs and tissues. According to the data analysis from recent studies in the past 20 years, nicotine exerts much more anti-inflammatory effects than pro-inflammatory ones, especially in ulcerative colitis, arthritis, sepsis, and endotoxemia. On the other hand, in oral inflammation, nicotine promotes and aggravates some diseases such as periodontitis and gingivitis, especially when there are harmful microorganisms in the oral cavity. We also carefully analyzed the nicotine dosage to determine its safe and effective range. Furthermore, we summarized the molecular mechanism of nicotine in these inflammatory diseases through regulating immune cells, immune factors, and the vagus and acetylcholinergic anti-inflammatory pathways. By balancing the “beneficial” and “harmful” effects of nicotine, it is meaningful to explore the effective medical value of nicotine and open up new horizons for remedying acute and chronic inflammation in humans.

Toxin-like peptides in plasma, urine and faecal samples from COVID-19 patients

Background: SARS-CoV-2 that causes COVID-19 disease and led to the pandemic currently affecting the world has been broadly investigated. Different studies have been performed to understand the infection mechanism, and the involved human genes, transcripts and proteins. In parallel, numerous clinical extra-pulmonary manifestations co-occurring with COVID-19 disease have been reported and evidence of their severity and persistence is increasing. Whether these manifestations are linked to other disorders co-occurring with SARS-CoV-2 infection, is under discussion. In this work, we report the identification of toxin-like peptides in COVID-19 patients by application of the Liquid Chromatography Surface-Activated Chemical Ionization – Cloud Ion Mobility Mass Spectrometry.  

Methods: Plasma, urine and faecal samples from COVID-19 patients and control individuals were analysed to study peptidomic toxins’ profiles. Protein precipitation preparation procedure was used for plasma, to remove high molecular weight proteins and efficiently solubilize the peptide fraction; in the case of faeces and urine, direct peptide solubilization was employed.  

Results: Toxin-like peptides, almost identical to toxic components of venoms from animals, like conotoxins, phospholipases, phosphodiesterases, zinc metal proteinases, and bradykinins, were identified in samples from COVID-19 patients, but not in control samples. 

Conclusions: The presence of toxin-like peptides could potentially be connected to SARS-CoV-2 infection. Their presence suggests a possible association between COVID-19 disease and the release in the body of (oligo-)peptides almost identical to toxic components of venoms from animals. Their involvement in a large set of heterogeneous extra-pulmonary COVID-19 clinical manifestations, like neurological ones, cannot be excluded. Although the presence of each individual symptom is not selective of the disease, their combination might be related to COVID-19 by the coexistence of the panel of the here detected toxin-like peptides. The presence of these peptides opens new scenarios on the aetiology of the COVID-19 clinical symptoms observed up to now, including neurological manifestations.

COVID-19-Related Mortality Risk in People With Severe Mental Illness: A Systematic and Critical Review

Background: Increasing clinical evidence suggests that people with severe mental illness (SMI), including schizophrenia spectrum disorders, bipolar disorder (BD), and major depressive disorder (MDD), are at higher risk of dying from COVID-19. Several systematic reviews examining the association between psychiatric disorders and COVID-19-related mortality have recently been published. Although these reviews have been conducted thoroughly, certain methodological limitations may hinder the accuracy of their research findings. Methods: A systematic literature search, using the PubMed, Embase, Web of Science, and Scopus databases (from inception to July 23, 2021), was conducted for observational studies assessing the risk of death associated with COVID-19 infection in adult patients with pre-existing schizophrenia spectrum disorders, BD, or MDD. Methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). Results: Of 1,446 records screened, 13 articles investigating the rates of death in patients with pre-existing SMI were included in this systematic review. Quality assessment scores of the included studies ranged from moderate to high. Most results seem to indicate that patients with SMI, particularly patients with schizophrenia spectrum disorders, are at significantly higher risk of COVID-19-related mortality, as compared to patients without SMI. However, the extent of the variation in COVID-19-related mortality rates between studies including people with schizophrenia spectrum disorders was large because of a low level of precision of the estimated mortality outcome(s) in certain studies. Most studies on MDD and BD did not include specific information on the mood state or disease severity of patients. Due to a lack of data, it remains unknown to what extent patients with BD are at increased risk of COVID-19-related mortality. A variety of factors are likely to contribute to the increased mortality risk of COVID-19 in these patients. These include male sex, older age, somatic comorbidities (particularly cardiovascular diseases), as well as disease-specific characteristics. Conclusion: Methodological limitations hamper the accuracy of COVID-19-related mortality estimates for the main categories of SMIs. Nevertheless, evidence suggests that SMI is associated with excess COVID-19 mortality. Policy makers therefore must consider these vulnerable individuals as a high-risk group that should be given particular attention. This means that targeted interventions to maximize vaccination uptake among these patients are required to address the higher burden of COVID-19 infection in this already disadvantaged group.

Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research

The appearance of the SARS-CoV-2 virus initiated many studies on the effects of the virus on the human body. So far, its negative influence on the functioning of many morphological and physiological units, including the nervous system, has been demonstrated. Consequently, research has been conducted on the changes that SARS-CoV-2 may cause in the cholinergic system. The aim of this study is to review the latest research from the years 2020/2021 regarding disorders in the cholinergic system caused by the SARS-CoV-2 virus. As a result of the research, it was found that the presence of the COVID-19 virus disrupts the activity of the cholinergic system, for example, causing the development of myasthenia gravis or a change in acetylcholine activity. The SARS-CoV-2 spike protein has a sequence similar to neurotoxins, capable of binding nicotinic acetylcholine receptors (nAChR). This may be proof that SARS-CoV-2 can bind nAChR. Nicotine and caffeine have similar structures to antiviral drugs, capable of binding angiotensin-converting enzyme 2 (ACE 2) epitopes that are recognized by SARS-CoV-2, with the potential to inhibit the formation of the ACE 2/SARS-CoV-2 complex. The blocking is enhanced when nicotine and caffeine are used together with antiviral drugs. This is proof that nAChR agonists can be used along with antiviral drugs in COVID-19 therapy. As a result, it is possible to develop COVID-19 therapies that use these compounds to reduce cytokine production. Another promising therapy is non-invasive stimulation of the vagus nerve, which soothes the body’s cytokine storm. Research on the influence of COVID-19 on the cholinergic system is an area that should continue to be developed as there is a need for further research. It can be firmly stated that COVID-19 causes a dysregulation of the cholinergic system, which leads to a need for further research, because there are many promising therapies that will prevent the SARS-CoV-2 virus from binding to the nicotinic receptor. There is a need for further research, both in vitro and in vivo. It should be noted that in the functioning of the cholinergic system and its connection with the activity of the COVID-19 virus, there might be many promising dependencies and solutions.

The Exposome and Immune Health in Times of the COVID-19 Pandemic

Growing evidence supports the importance of lifestyle and environmental exposures-collectively referred to as the 'exposome'-for ensuring immune health. In this narrative review, we summarize and discuss the effects of the different exposome components (physical activity, body weight management, diet, sun exposure, stress, sleep and circadian rhythms, pollution, smoking, and gut microbiome) on immune function and inflammation, particularly in the context of the current coronavirus disease 2019 (COVID-19) pandemic. We highlight the potential role of 'exposome improvements' in the prevention-or amelioration, once established-of this disease as well as their effect on the response to vaccination. In light of the existing evidence, the promotion of a healthy exposome should be a cornerstone in the prevention and management of the COVID-19 pandemic and other eventual pandemics.

Nicotinic Acetylcholine Receptors in the Respiratory Tract

Nicotinic acetylcholine receptors (nAChR) are widely distributed in neuronal and non-neuronal tissues, where they play diverse physiological roles. In this review, we highlight the recent findings regarding the role of nAChR in the respiratory tract with a special focus on the involvement of nAChR in the regulation of multiple processes in health and disease. We discuss the role of nAChR in mucociliary clearance, inflammation, and infection and in airway diseases such as asthma, chronic obstructive pulmonary disease, and cancer. The subtype diversity of nAChR enables differential regulation, making them a suitable pharmaceutical target in many diseases. The stimulation of the α3β4 nAChR could be beneficial in diseases accompanied by impaired mucociliary clearance, and the anti-inflammatory effect due to an α7 nAChR stimulation could alleviate symptoms in diseases with chronic inflammation such as chronic obstructive pulmonary disease and asthma, while the inhibition of the α5 nAChR could potentially be applied in non-small cell lung cancer treatment. However, while clinical studies targeting nAChR in the airways are still lacking, we suggest that more detailed research into this topic and possible pharmaceutical applications could represent a valuable tool to alleviate the symptoms of diverse airway diseases.

Twitter Discourse on Nicotine as Potential Prophylactic or Therapeutic for COVID-19

Background:

An unproven “nicotine hypothesis” that indicates nicotine’s therapeutic potential for COVID-19 has been proposed in recent literature. This study is about Twitter posts that misinterpret this hypothesis to make baseless claims about benefits of smoking and vaping in the context of COVID-19. We quantify the presence of such misinformation and characterize the tweeters who post such messages.

Methods:

Twitter premium API was used to download tweets (n = 17,533) that match terms indicating (a) nicotine or vaping themes, (b) a prophylactic or therapeutic effect, and (c) COVID-19 (January-July 2020) as a conjunctive query. A constraint on the length of the span of text containing the terms in the tweets allowed us to focus on those that convey the therapeutic intent. We hand-annotated these filtered tweets and built a classifier that identifies tweets that extrapolate the nicotine hypothesis to smoking/vaping with a positive predictive value of 85%. We analyzed the frequently used terms in author bios, top Web links, and hashtags of such tweets.

Results:

21% of our filtered COVID-19 tweets indicate a vaping or smoking-based prevention/treatment narrative. Qualitative analyses show a variety of ways therapeutic claims are being made and tweeter bios reveal pre-existing notions of positive stances toward vaping.

Conclusion:

The social media landscape is a double-edged sword in tobacco communication. Although it increases information reach, consumers can also be subject to confirmation bias when exposed to inadvertent or deliberate framing of scientific discourse that may border on misinformation. This calls for circumspection and additional planning in countering such narratives as the COVID-19 pandemic continues to ravage our world. Our results also serve as a cautionary tale in how social media can be leveraged to spread misleading information about tobacco products in the wake of pandemics.

NAChRDB: A Web Resource of Structure-Function Annotations to Unravel the Allostery of Nicotinic Acetylcholine Receptors

Nicotinic acetylcholine receptors (nAChRs) comprise a large and ancient family of allosteric ion channels mediating synaptic transmission. The vast knowledge about nAChRs has become difficult to navigate. NAChRDB is a web-accessible resource of curated residue-level functional annotations of neuromuscular nAChRs. Interactive three-dimensional (3D) visualization and sequence alignment give further context to this rich and growing collection of experimental observations and computational predictions. NAChRDB is freely available at https://crocodile.ncbr.muni.cz/Apps/NAChRDB/, with interactive tutorials and regular updates to the content and web interface. No installation or user registration is required. NAChRDB is accessible through any modern internet browser on desktops and mobile devices. By providing immediate and systematic access to practical knowledge gained through decades of research, NAChRDB represents a powerful educational tool and helps guide discovery by revealing gaps in current knowledge and aiding the interpretation of results of molecular and structural biology experiments or computational studies.

Attenuation of clinical and immunological outcomes during SARS-CoV-2 infection by ivermectin

The devastating pandemic due to SARS-CoV-2 and the emergence of antigenic variants that jeopardize the efficacy of current vaccines create an urgent need for a comprehensive understanding of the pathophysiology of COVID-19, including the contribution of inflammation to disease. It also warrants for the search of immunomodulatory drugs that could improve disease outcome. Here, we show that standard doses of ivermectin (IVM), an anti-parasitic drug with potential immunomodulatory activities through the cholinergic anti-inflammatory pathway, prevent clinical deterioration, reduce olfactory deficit, and limit the inflammation of the upper and lower respiratory tracts in SARS-CoV-2-infected hamsters. Whereas it has no effect on viral load in the airways of infected animals, transcriptomic analyses of infected lungs reveal that IVM dampens type I interferon responses and modulates several other inflammatory pathways. In particular, IVM dramatically reduces the Il-6/Il-10 ratio in lung tissue and promotes macrophage M2 polarization, which might account for the more favorable clinical presentation of IVM-treated animals. Altogether, this study supports the use of immunomodulatory drugs such as IVM, to improve the clinical condition of SARS-CoV-2-infected patients.

Toxin-like peptides in plasma, urine and faecal samples from COVID-19 patients

Background: SARS-CoV-2 that causes COVID-19 disease and led to the pandemic currently affecting the world has been broadly investigated. Different studies have been performed to understand the infection mechanism, and the involved human genes, transcripts and proteins. In parallel, numerous clinical extra-pulmonary manifestations co-occurring with COVID-19 disease have been reported and evidence of their severity and persistence is increasing. Whether these manifestations are linked to other disorders co-occurring with SARS-CoV-2 infection, is under discussion. In this work, we report the identification of toxin-like peptides in COVID-19 patients by application of the Liquid Chromatography Surface-Activated Chemical Ionization - Cloud Ion Mobility Mass Spectrometry.   Methods: Plasma, urine and faecal samples from COVID-19 patients and control individuals were analysed to study peptidomic toxins' profiles. Protein precipitation preparation procedure was used for plasma, to remove high molecular weight proteins and efficiently solubilize the peptide fraction; in the case of faeces and urine, direct peptide solubilization was employed.   Results: Toxin-like peptides, almost identical to toxic components of venoms from animals, like conotoxins, phospholipases, phosphodiesterases, zinc metal proteinases, and bradykinins, were identified in samples from COVID-19 patients, but not in control samples.  Conclusions: The presence of toxin-like peptides could potentially be connected to SARS-CoV-2 infection. Their presence suggests a possible association between COVID-19 disease and the release in the body of (oligo-)peptides almost identical to toxic components of venoms from animals. Their involvement in a large set of heterogeneous extra-pulmonary COVID-19 clinical manifestations, like neurological ones, cannot be excluded. Although the presence of each individual symptom is not selective of the disease, their combination might be related to COVID-19 by the coexistence of the panel of the here detected toxin-like peptides. The presence of these peptides opens new scenarios on the aetiology of the COVID-19 clinical symptoms observed up to now, including neurological manifestations.

Lower Gene Expression of Angiotensin Converting Enzyme 2 Receptor in Lung Tissues of Smokers with COVID-19 Pneumonia

Angiotensin-converting enzyme 2 (ACE-2) is the main cell entry receptor for severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2), thus playing a critical role in causing Coronavirus disease 2019 (COVID-19). The role of smoking habit in the susceptibility to infection is still controversial. In this study we correlated lung ACE-2 gene expression with several clinical/pathological data to explore susceptibility to infection. This is a retrospective observational study on 29 consecutive COVID-19 autopsies. SARS-CoV-2 genome and ACE-2 mRNA expression were evaluated by real-time polymerase chain reaction in lung tissue samples and correlated with several data with focus on smoking habit. Smoking was less frequent in high than low ACE-2 expressors (p = 0.014). A Bayesian regression also including age, gender, hypertension, and virus quantity confirmed that smoking was the most probable risk factor associated with low ACE-2 expression in the model. A direct relation was found between viral quantity and ACE-2 expression (p = 0.028). Finally, high ACE-2 expressors more frequently showed a prevalent pattern of vascular injury than low expressors (p = 0.049). In conclusion, ACE-2 levels were decreased in the lung tissue of smokers with severe COVID-19 pneumonia. These results point out complex biological interactions between SARS-CoV-2 and ACE-2 particularly concerning the aspect of smoking habit and need larger prospective case series and translational studies.

Novel Pharmacotherapies in Parkinson's Disease

Parkinson’s disease (PD), an age-related progressive neurodegenerative condition, is associated with loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc), which results in motor deficits characterized by the following: akinesia, rigidity, resting tremor, and postural instability, as well as nonmotor symptoms such as emotional changes, particularly depression, cognitive impairment, gastrointestinal, and autonomic dysfunction. The most common treatment for PD is focused on dopamine (DA) replacement (e.g., levodopa = L-Dopa), which unfortunately losses its efficacy over months or years and can induce severe dyskinesia. Hence, more efficacious interventions without such adverse effects are urgently needed. In this review, following a general description of PD, potential novel therapeutic interventions for this devastating disease are examined. Specifically, the focus is on nicotine and nicotinic cholinergic system, as well as butyrate, a short chain fatty acid (SCFA), and fatty acid receptors.

The Cholinergic and ACE-2-Dependent Anti-Inflammatory Systems in the Lung: New Scenarios Emerging From COVID-19

The renin angiotensin system and the cholinergic anti-inflammatory pathway have been recently shown to modulate lung inflammation in patients with COVID-19. We will show how studies performed on this disease are starting to provide evidence that these two anti-inflammatory systems may functionally interact with each other, a mechanism that could have a more general physiological relevance than only COVID-19 infection.

SARS-Cov-2 spike protein fragment 674-685 protects mitochondria from releasing cytochrome c in response to apoptogenic influence

In spite of numerous studies, many details of SARS-Cov-2 interaction with human cells are still poorly understood. The 674–685 fragment of SARS-Cov-2 spike protein is homologous to the fragment of α-cobratoxin underlying its interaction with α7 nicotinic acetylcholine receptors (nAChRs). The interaction of 674–685 peptide with α7 nAChR has been predicted in silico. In the present paper we confirm this prediction experimentally and investigate the effect of SARS-Cov-2 spike protein peptide on mitochondria, which express α7 nAChRs to regulate apoptosis-related events. We demonstrate that SARS-Cov-2 spike protein peptide 674–685 competes with the antibody against 179–190 fragment of α7 nAChR subunit for the binding to α7-expressing cells and mitochondria and prevents the release of cytochrome c from isolated mitochondria in response to 0.5 mM H₂O₂ but does not protect intact U373 cells against apoptogenic effect of H₂O_2. Our data suggest that the α7 nAChR-binding portion of SARS-Cov-2 spike protein prevents mitochondria-driven apoptosis when the virus is uncoated inside the cell and, therefore, supports the infected cell viability before the virus replication cycle is complete.

Nicotine upregulates ACE2 expression and increases competence for SARS-CoV-2 in human pneumocytes

The coronavirus disease 2019 (COVID-19) pandemic has a variable degree of severity according to underlying comorbidities and life-style. Several research groups have reported an association between cigarette smoking and increased severity of COVID-19. The exact mechanism of action is largely unclear. We exposed low angiotensin-converting enzyme 2 (ACE2)-expressing human pulmonary adenocarcinoma A549 epithelial cells to nicotine and assessed ACE2 expression at different times. We further used the nicotine-exposed cells in a virus neutralisation assay. Nicotine exposure induces rapid and long-lasting increases in gene and protein expression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor ACE2, which in turn translates into increased competence for SARS-CoV-2 replication and cytopathic effect. These findings show that nicotine worsens SARS-CoV-2 pulmonary infection and have implications for public health policies.

A potential interaction between the SARS-CoV-2 spike protein and nicotinic acetylcholine receptors

Changeux et al. (Changeux et al. C. R. Biol. 343:33-39.) recently suggested that the SARS-CoV-2 spike protein may interact with nicotinic acetylcholine receptors (nAChRs) and that such interactions may be involved in pathology and infectivity. This hypothesis is based on the fact that the SARS-CoV-2 spike protein contains a sequence motif similar to known nAChR antagonists. Here, we use molecular simulations of validated atomically detailed structures of nAChRs and of the spike to investigate the possible binding of the Y674-R685 region of the spike to nAChRs. We examine the binding of the Y674-R685 loop to three nAChRs, namely the human α4β2 and α7 subtypes and the muscle-like αβγδ receptor from Tetronarce californica. Our results predict that Y674-R685 has affinity for nAChRs. The region of the spike responsible for binding contains a PRRA motif, a four-residue insertion not found in other SARS-like coronaviruses. The conformational behavior of the bound Y674-R685 is highly dependent on the receptor subtype; it adopts extended conformations in the α4β2 and α7 complexes but is more compact when bound to the muscle-like receptor. In the α4β2 and αβγδ complexes, the interaction of Y674-R685 with the receptors forces the loop C region to adopt an open conformation, similar to other known nAChR antagonists. In contrast, in the α7 complex, Y674-R685 penetrates deeply into the binding pocket in which it forms interactions with the residues lining the aromatic box, namely with TrpB, TyrC1, and TyrC2. Estimates of binding energy suggest that Y674-R685 forms stable complexes with all three nAChR subtypes. Analyses of simulations of the glycosylated spike show that the Y674-R685 region is accessible for binding. We suggest a potential binding orientation of the spike protein with nAChRs, in which they are in a nonparallel arrangement to one another.

COVID-19: Why does disease severity vary among individuals?

The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is responsible for the current pandemic, coronavirus disease 2019 (COVID-19). While all people are susceptible to the SARS-CoV-2 infection, the nature and severity of the disease vary significantly among individuals and populations. Importantly, reported disease burdens and case fatality rates differ considerably from country to country. There are, however, still uncertainties about the severity of the disease among individuals or the reason behind a more severe disease in some cases. There is a strong possibility that the severity of this disease depends on a complicated interaction between the host, virus, and environment, which leads to different clinical outcomes. The objective of this article is to point out the essential influential factors related to the host, virus, and environment affecting the clinical outcome of COVID-19.

Drug repurposing for COVID-19 via knowledge graph completion

OBJECTIVE

To discover candidate drugs to repurpose for COVID-19 using literature-derived knowledge and knowledge graph completion methods.

METHODS

We propose a novel, integrative, and neural network-based literature-based discovery (LBD) approach to identify drug candidates from PubMed and other COVID-19-focused research literature. Our approach relies on semantic triples extracted using SemRep (via SemMedDB). We identified an informative and accurate subset of semantic triples using filtering rules and an accuracy classifier developed on a BERT variant. We used this subset to construct a knowledge graph, and applied five state-of-the-art, neural knowledge graph completion algorithms (i.e., TransE, RotatE, DistMult, ComplEx, and STELP) to predict drug repurposing candidates. The models were trained and assessed using a time slicing approach and the predicted drugs were compared with a list of drugs reported in the literature and evaluated in clinical trials. These models were complemented by a discovery pattern-based approach.

RESULTS

Accuracy classifier based on PubMedBERT achieved the best performance (F1 = 0.854) in identifying accurate semantic predications. Among five knowledge graph completion models, TransE outperformed others (MR = 0.923, Hits@1 = 0.417). Some known drugs linked to COVID-19 in the literature were identified, as well as others that have not yet been studied. Discovery patterns enabled identification of additional candidate drugs and generation of plausible hypotheses regarding the links between the candidate drugs and COVID-19. Among them, five highly ranked and novel drugs (i.e., paclitaxel, SB 203580, alpha 2-antiplasmin, metoclopramide, and oxymatrine) and the mechanistic explanations for their potential use are further discussed.

CONCLUSION

We showed that a LBD approach can be feasible not only for discovering drug candidates for COVID-19, but also for generating mechanistic explanations. Our approach can be generalized to other diseases as well as to other clinical questions. Source code and data are available at https://github.com/kilicogluh/lbd-covid.

Smoking and COVID-19: A Scoping Review

Smoking affects a person’s overall health and damages nearly every organ of the body. Since smoking tobacco affects and damages the lungs, it increases the risk of respiratory infections and makes it easier for the coronavirus disease (COVID-19) to invade the lung tissue, causing more severe symptoms and increasing the risk of death. However, debates are still ongoing as to the effect of cigarette smoking on vulnerability to COVID-19. Some studies, where active smokers were underrepresented among patients with COVID-19, claimed that a “smoker’s paradox” may exist in COVID-19 and that smokers are protected from infection and severe complications of COVID-19. However, other studies reported the opposite trend. The objective of this study is to review the findings of epidemiological and in vitro studies about the association between smoking and the risk of contracting COVID-19, taking into account disease severity. Several epidemiological studies have found a higher smoking prevalence among COVID-19 infected patients. Also, studies had shown that people with respiratory diseases caused by tobacco use are at higher risk of developing severe COVID-19 symptoms. Studies have shown that in vitro, the acute exposure allows for more severe proximal airway epithelial disease from SARS-CoV-2 by reducing the mucosal innate immune response and the proliferation of airway basal stem cells and has implications for disease spread and severity in people exposed to cigarette smoke, with a more severe viral infection and cell death. Smoker patients with different comorbidities are at higher risk of contracting the COVID-19 virus and have a worse prognosis for the virus as well as for their comorbidities. Further investigations of the interaction between smoking and COVID-19 are warranted to accurately assess the risk of contracting COVID-19 among smokers, and the progression to mechanical ventilation or death in patients who suffer from it.

Alcohol- and Cigarette-Use Related Behaviors During Quarantine and Physical Distancing Amid COVID-19 in Indonesia

Background: In light of the coronavirus disease 2019 (COVID-19) pandemic, Indonesia implemented large-scale social restrictions (pembatasan sosial berskala besar/PSBB) to combat the spread of COVID-19, which might influence addictive behaviors. The current study aimed to explore the fluctuation of substance use during the pandemic and association of physical distancing and related factors toward consumption of alcohol and cigarettes. Method: An online survey was conducted from April 28 to June 1, 2020. Data regarding sociodemographic information, physical distancing profile, alcohol and cigarette usages, Alcohol Use Disorders Identification Test (AUDIT), Cigarette Dependence Scale (CDS), Symptom Checklist-90, and Pittsburg Sleep Quality Index (PSQI) were collected. A total of 4,584 respondents from all 34 provinces in Indonesia completed the survey. Data were summarized descriptively and analyzed using chi-square, ANOVA, and multinomial regression on SPSS 23.0 for Windows. Results: This study found that during the COVID-19 pandemic in Indonesia alcohol consumption was 9.50% and daily cigarette smoking was 20.3%. Around 44.5% and 47.6% of respondents reported stable alcohol consumption and cigarette consumption, respectively. The mean AUDIT score was 3.52 ± 4.66 and the mean CDS score was 24.73 ± 8.86. Physical distancing was not correlated to any substance use changes. Increased alcohol consumption was negatively correlated with being unmarried and positively correlated with a higher PSQI score. Decreased alcohol use positively correlated with living in PSBB-implementing provinces and higher AUDIT scores when compared to stable alcohol drinking. Increased cigarette smoking was positively correlated with being male, unmarried, and higher CDS scores. Reduced cigarette smoking was negatively correlated with living in provinces implementing PSBB, higher CDS scores, and phobic anxiety, hostility, and psychoticism subscales of SCL-90. Discussion and Conclusion: The prevalence of alcohol and cigarette consumption changes showed a similar trend with other available studies in other countries. This study established that substance use was mainly sustained with a smaller proportion of respondents amplifying their substance usages. The changes were correlated with PSBB policy but not the practice of physical distancing. Psychiatry and addiction services in Indonesia should be strengthened to cope with the increased burden of psychological distress. Future studies should conduct more comparisons to determine whether the overall rising intensity of consumption was maintained post-pandemic and delineate acute psychopathologies' effects on substance use.

Spotlight on COVID-19: from biology to therapy and prevention

In this COVID-19 Focus Issue, we highlight a collection of recently published The FEBS Journal articles that consider the broader aspects of the COVID-19 pandemic, ranging from the debunking of urban myths to highlighting some of the most pressing questions concerning SARS-CoV-2 infection, treatment, prevention and pathology. The collection comprises two review articles, six Viewpoints, two research papers and one commentary. We hope that these articles will provide readers with an informative and interesting overview that will promote further critical analysis of currently available data and observations on COVID-19.

The FEBS Journal in 2021: a sharp reminder that science really matters

The FEBS Journal, a leading multidisciplinary journal in the life sciences, continues to grow in visibility and impact. Here, the Editor-in-Chief Seamus Martin discusses developments at the journal over the past year and the impact of the COVID-19 crisis on research activities.

Evaluation of Smoking and Asymptomatic COVID-19 Disease in Health Professionals

Aim: This study was conducted to assess smoking status and COVID-19 clinical severity in health professionals of a pandemic health center. Methods: A retrospective study design based on data reports of a tertiary hospital between March 2020 and June 2020 was realized. A comparison between the clinical disease severity and smoking status was analyzed by the SPSS 22.0 software statistic program at a significance level of p <0.05 value. Results: 150 participants (age 31.19±8.92 years; 48% female) were evaluated for the COVID disease clinical severity between the smokers (10.6%; 16/150) and non-smokers. The presence of asymptomatic (carriers) clinical disease (24%; 36/150) was found to be statistically significant in favor of smokers (8/16) versus non-smokers (28/134). Nicotine dependence level and Fagerstrom score had no clinical difference. Also, the occupation was significant for disease severity. Smokers among permanent workers with COVID versus doctors and nurses had a higher percentage in belong to the asymptomatic clinic (26/36) despite the higher rate of smoking (11/16). Conclusion: It was emphasized that higher rates of asymptomatic disease among smokers than that of symptomatic disease. Our study might contribute to epidemic control efforts that would help to explain the asymptomatic clinic and the different rates between smokers and non-smokers. Keywords: COVID-19, medical staff, nicotine dependence, smoking

A Systematic Review and Meta-Analysis of Hospitalised Current Smokers and COVID-19

SARS-CoV-2 is a new coronavirus that has caused a worldwide pandemic. It produces severe acute respiratory disease (COVID-19), which is fatal in many cases, characterised by the cytokine release syndrome (CRS). According to the World Health Organization, those who smoke are likely to be more vulnerable to infection. Here, in order to clarify the epidemiologic relationship between smoking and COVID-19, we present a systematic literature review until 28th April 2020 and a meta-analysis. We included 18 recent COVID-19 clinical and epidemiological studies based on smoking patient status from 720 initial studies in China, the USA, and Italy. The percentage of hospitalised current smokers was 7.7% (95% CI: 6.9-8.4) in China, 2.3% (95% CI: 1.7-2.9) in the USA and 7.6% (95% CI: 4.2-11.0) in Italy. These percentages were compared to the smoking prevalence of each country and statistically significant differences were found in them all (p < 0.0001). By means of the meta-analysis, we offer epidemiological evidence showing that smokers were statistically less likely to be hospitalised (OR = 0.18, 95% CI: 0.14-0.23, p < 0.01). In conclusion, the analysis of data from 18 studies shows a much lower percentage of hospitalised current smokers than expected. As more studies become available, this trend should be checked to obtain conclusive results and to explore, where appropriate, the underlying mechanism of the severe progression and adverse outcomes of COVID-19.