The role of miRNAs in viral myocarditis, and its possible implication in induction of mRNA-based COVID-19 vaccines-induced myocarditis.

Background: Several reports of unheeded complications secondary to the current mass international rollout of SARS-COV-2 vaccines, one of which is myocarditis occurring with the FDA fully approved vaccine, Pfizer, and others. Main body of the abstract: Certain miRNAs (non-coding RNA sequences) are involved in the pathogenesis in viral myocarditis, and those miRNAs are interestingly upregulated in severe COVID-19. We hypothesize that the use of mRNA-based vaccines may be triggering the release of host miRNAs or that trigger the occurrence of myocarditis. This is based on the finding of altered host miRNA expression promoting virus-induced myocarditis. Short conclusion: In conclusion, miRNAs are likely implicated in myocarditis associated with mRNA vaccines. Our hypothesis suggests the use of miRNA as a biomarker for the diagnosis of mRNA vaccine-induced myocarditis. Additionally, the interplay between viral miRNA and the host immune system could alter inflammatory profiles, hence suggesting the use of therapeutic inhibition to prevent such complications.

Should we vaccinate the better seroconverters or the most vulnerable? Game changing insights for COVID-19 vaccine prioritization policies

BackgroundWith the rapid rise in COVID 19 cases incomparable to the number of vaccinations available, there has been a demand to prioritize the older age groups receiving the vaccine as they have more risk of morbidity and mortality and thus better outcome from vaccination.Main bodySome studies showed a lower seroconversion rate in older group patients;thus, we discuss the necessity to reprioritize vaccinations to younger age groups who have better seroconversion rates, but we may face some ethical dilemma that could hinder our hypothesis. Decreased seroconversion rates in adults are attributable to immuno-senescence which involves a decrease in humoral and cellular-mediated immunity with age. Despite this fact, there remains some ethical dilemma that can hinder widespread vaccination of younger generations, the most important of which is the unknown long-term effects of COVID-19 vaccines due their fast-tracking under the pressure of the pandemic.Short conclusionPrioritizing children vaccination against COVID-19 seems an interesting strategy that can help in containing the pandemic. Resolving some ethical dilemma needs to be done before implementing such strategy.

From HIV to COVID-19, Molecular mechanisms of pathogens' trade-off and persistence in the community, potential targets for new drug development.

Background: On the staggering emergence of the Omicron variant, numerous questions arose about the evolution of virulence and transmissibility in microbes. Main body of the abstract: The trade-off hypothesis has long speculated the exchange of virulence for the sake of superior transmissibility in a wide array of pathogens. While this certainly applies to the case of the Omicron variant, along with influenza virus, various reports have been allocated for an array of pathogens such as human immunodeficiency virus (HIV), malaria, hepatitis B virus (HBV) and tuberculosis (TB). The latter abide to another form of trade-off, the invasion-persistence trade-off. In this study, we aim to explore the molecular mechanisms and mutations of different obligate intracellular pathogens that attenuated their more morbid characters, virulence in acute infections and invasion in chronic infections. Short conclusion: Recognizing the mutations that attenuate the most morbid characters of pathogens such as virulence or persistence can help in tailoring new therapies for such pathogens. Targeting macrophage tropism of HIV by carbohydrate-binding agents, or targeting the TMPRSS2 receptors to prevent pulmonary infiltrates of COVID-19 is an example of how important is to recognize such genetic mechanisms.

The potential role of inhaled nitric oxide for postexposure chemoprophylaxis of COVID-19.

BACKGROUND: Several vaccines have been fast-tracked in an attempt to decrease the morbidity and mortality of COVID-19. However, post-exposure prophylaxis has been overlooked in battling COVID-19. MAIN TEXT: Inhaled nitric oxide is a potential tool in post-exposure prophylaxis of COVID-19. It decreases cytosolic calcium levels, which impairs the action of Furin. SARS-CoV-2 uses Furin to replicate in the respiratory tract. SHORT CONCLUSION: Inhaled nitric oxide could decrease the viral load in the upper respiratory tract, abort clinically symptomatic infection, and prevent subsequent complications. Nitric oxide might be a tool for post-exposure chemoprophylaxis in at-risk groups, especially medical personnel.

Salivary markers and coronavirus disease 2019: insights from cross-talk between the oral microbiome and pulmonary and systemic low-grade inflammation and implications for vascular complications.

To date, coronavirus disease 2019 (COVID-19) has affected over 6.2 million individuals worldwide, including 1.46 million deaths. COVID-19 complications are mainly induced by low-grade inflammation-causing vascular degeneration. There is an increasing body of evidence that suggests that oral dysbiotic taxa are associated with worse prognosis in COVID-19 patients, especially the Prevotella genus, which was retrieved from nasopharyngeal and bronchoalveolar lavage samples in affected patients. Oral dysbiosis may act by increasing the likelihood of vascular complications through low-grade inflammation, as well as impairing respiratory mucosal barrier mechanisms against SARS-CoV-2. Salivary markers can be used to reflect this oral dysbiosis and its subsequent damaging effects on and the lungs and vasculature. Salivary sampling can be self-collected, and is less costly and less invasive, and thus may be a superior option to serum markers in risk stratification of COVID-19 patients. Prospective studies are needed to confirm such hypothesis. Video Abstract: http://links.lww.com/CAEN/A28.

JAK out of the Box; The Rationale behind Janus Kinase Inhibitors in the COVID-19 setting, and their potential in obese and diabetic populations.

The adaptive use of Janus kinase (JAK)-inhibitors has been suggested by rheumatology experts in the management of COVID-19. We recount the rationale behind their use in this setting, and the current evidence for and against their use in this review. JAK-inhibitors role in COVID-19 infection appears to be multifaceted, including preventing viral endocytosis and dampening the effect of excessive chemokines. This drug class may be able to achieve these effects at already preapproved dosages. Concerns arise regarding reactivation of latent viral infections and the feasibility of their use in those with severe disease. Most interestingly, JAK-Inhibitors may also have an additional advantage for diabetic and obese populations, where the dysregulation of JAK-signal transducer and activator of transcription pathway may be responsible for their increased risk of poor outcomes. Targeting this pathway may provide a therapeutic advantage for these patient groups.

PPAR agonists as effective adjuvants for COVID-19 vaccines, by modifying immunogenetics: a review of literature.

BACKGROUND: Several coronavirus vaccine have been fast-tracked to halt the pandemic, the usage of immune adjuvants that can boost immunological memory has come up to the surface. This is particularly of importance in view of the rates of failure of seroconversion and re-infection after COVID-19 infection, which could make the vaccine role and response debatable. Peroxisome proliferator-activated receptors (PPARs) have an established immune-modulatory role, but their effects as adjuvants to vaccination have not been explored to date. It is increasingly recognized that PPAR agonists can upregulate the levels of anti-apoptotic factors such as MCL-1. Such effect can improve the results of vaccination by enhancing the longevity of long-lived plasma cells (LLPCs). The interaction between PPAR agonists and the immune system does not halt here, as T cell memory is also stimulated through enhanced T regulatory cells, antagonizing PD-L1 and switching the metabolism of T cells to fatty acid oxidation, which has a remarkable effect on the persistence of T memory cells. What is even of a more significant value is the effect of PPAR gamma on ensuring a profound secretion of antibodies upon re-exposure to the offending antigen through upregulating lipoxin B4, therefore potentially assisting the vaccine response and deterring re-infection. SHORT CONCLUSION: In view of the above, we suggest the use of PPAR as adjuvants to vaccines in general especially the emerging COVID-19 vaccine due to their role in enhancing immunologic memory through DNA-dependent mechanisms.

Obese communities among the best predictors of COVID-19-related deaths.

Coronavirus disease 2019 (COVID-19) is the largest outbreak to strike the world since the Spanish flu in 1918. Visual examination of the world map shows a wide variation of death tolls between countries. The main goal of our series is to determine the best predictors of such discrepancy. METHODS: This is a retrospective study in which the rate of COVID-19 deaths was correlated with each of the following independent variables: total tests per 1 million population, gross domestic product (GDP), average temperatures per country, ultraviolet index, median age, average BMI per country, food supply, Bacille Calmette-Guerin compulsory status, and passenger traffic. RESULTS: BMI per country proved to be the second best predictor of death rate with an R value of 0.43, and GDP being the best predictor with R = 0.65. CONCLUSION: This article shows a tight correlation between average BMI, food supply per country, and COVID-19-related deaths. Such predisposing factors might operate by upregulating the inflammation pathway in heavily struck countries, leading to easier triggering of the infamous cytokine storm syndrome. Obesity also increases cardiovascular and respiratory morbidities, which are coupled to increased ICU demand and deaths among infected cases.Video abstract: http://links.lww.com/CAEN/A25.

COVID-19 during pregnancy should we really worry from vertical transmission or rather from fetal hypoxia and placental insufficiency? A systematic review

Background: COVID-19 is the largest outbreak to strike humanity. The wide scale of fatalities and morbidities lead to a concurrent pandemic of uncertainty in scientic evidence. Conicting evidences are released on daily basis about the neonatal outcomes of COVID-19 positive mothers. The aim of this study was to use the relevant case reports and series to determine the percentage of newborns who test positive in COVID-19 positive mothers. Secondary outcomes included examining laboratory and placental abnormalities among fetus-mother pairs. Methods: Systematic review was performed on all studies reporting primary data on fetus-mother pairs with COVID-19. Data bases were searched for studies that met our inclusion and exclusion criteria. Results: Final screening revealed 66 studies, from which the primary data of 1787 mother-infant pairs was obtained. Only 2.8% of mother infant pairs were tested positive, and this nding is identical to percentages reported in former coronaviridae outbreaks. Whereas, 20% manifested with intrauterine hypoxia alongside placental abnormalities suggestive of heavy placental vaso-occlusive involvement. Conclusions: These ndings suggest that while vertical transmission is unlikely, there appears to be an underlying risk of placental insuciency due to the prothrombotic tendency observed in COVID-19 infection. Guidelines for proper prophylactic anticoagulation in COVID positive mothers need to be established.

Advanced Echocardiography Techniques: The Future Stethoscope of Systemic Diseases.

Cardiovascular disease (CVD) has been showing patterns of extensive rise in prevalence in the contemporary era, affecting the quality of life of millions of people and leading the causes of death worldwide. It has been a provocative challenge for modern medicine to diagnose CVD in its crib, owing to its etiological factors being attributed to a large array of systemic diseases, as well as its non-binary hideous nature that gradually leads to functional disability. Novel echocardiography techniques have enabled the cardiac ultrasound to provide a comprehensive analysis of the heart in an objective, feasible, time- and cost-effective manner. Speckle tracking echocardiography, contrast echocardiography, and 3D echocardiography have shown the highest potential for widespread use. The uses of novel modalities have been elaborately demonstrated in this study as a proof of concept that echocardiography has a place in routine general practice with supportive evidence being as recent as its role in the concurrent COVID-19 pandemic. Despite such evidence, many uses remain off-label and unexploited in practice. Generalization of echocardiography at the point of care can become a much-needed turning point in the clinical approach to case management. To actualize such aspirations, we recommend further prospective and interventional studies to examine the effect of implementing advanced techniques at the point of care on the decision-making process and evaluate their effectiveness in prevention of cardiovascular morbidities and mortalities.

The potential use of lactate blockers for the prevention of COVID-19 worst outcome, insights from exercise immunology.

Following the decline in Physical Activity (PA) due to COVID-19 restrictions in the form of government mandated lockdowns and closures of public spaces, the modulatory effect of physical exercise on immunity is being heavily revisited. In an attempt to comprehend the wide discrepancy in patient response to COVID-19 and the factors that potentially modulate it, we summarize the findings relating PA to inflammation and immunity. A distinction is drawn between moderate intensity and high intensity physical exercise based on the high lactate production observed in the latter. We hypothesize that, the lactate production associated with high intensity anaerobic exercise is implicated in the modulation of several components of the innate and adaptive immunity. In this review, we also summarize these immunomodulatory effects of lactate. These include increasing serum IL-6 levels, the main mediator of cytokine storms, as well as affecting NK cells, Macrophages, Dendritic cells and cytotoxic T-lymphocytes. The implications of high lactate levels in athletic performance are highlighted where athletes should undergo endurance training to increase VO2 max and minimize lactate production. Tumor models of hypoxia were also reported where lactate levels are elevated leading to increased invasiveness and angiogenesis. Accordingly, the novel lactate blocking strategy employed in cancer treatment is evaluated for its potential benefit in COVID-19 in addition to the readily available beta-blockers as an antagonist to lactate. Finally, we suggest the diagnostic/prognostic purpose of the elevated lactate levels that can be determined through sweat lactate testing. It is the detrimental effect of lactate on immunity and its presence in sweat that qualify it to be used as a potential non-invasive marker of poor COVID-19 outcome.

Hypoxia-inducible factor (HIF): The link between obesity and COVID-19.

The COVID-19 death toll has involved to date more than 1 million confirmed deaths. The death rate is even higher in the obese COVID-19 patients, as a result of hypoxia, due to the interplay between adipose tissue hypoxia and obstructive sleep apnea. The discrepancy of manifestations seen in COVID-19 seems to be mediated by a differential immune response rather than a differential viral load. One of the key players of the immune response is HIF. HIF-1ß is a stable constitutively expressed protein in the nucleus; and under hypoxic changes, its activity is unaffected, whereas the HIF-α subunit has a short half-life and because of its degradation by an enzyme known as propyl hydroxylase; under hypoxic conditions, propyl hydroxylase gets deactivated thus leading to the stabilization of HIF-1α. As mentioned before, HIF-1α expression is triggered by hypoxic states, this crippling condition will aggravate the pro-inflammatory characteristics of HIF-1α. The vast majority of decompensated COVID19 cases manifest with drastic lung injury and severe viral pneumonia, the infection-induced hypoxia will the existing hypoxia in obesity. This will additionally augment HIF-1α levels that will provoke the already existing cytokines' storm to fulminant. Consequently, this will directly correlate the effect of a hypoxic environment with the increase of HIF-1α level. HIFɑ exists in two main isoforms HIF-1α and HIF-2α. HIF-1α and HIF-2α act in distinct ways in how they work on different target genes. For example, HIF-2α may act on hemopoietin genes (heme-regulating genes); while HIF-1α acts on EPO. HIF-1α release seems to be markedly augmented in obesity due to adipose tissue hypoxia and obstructive sleep apnea resulting in cyclic hypoxia. HIF-1α can also be secreted by direct viral proteolytic effects. Whereas, HIF-2α is stimulated by chronic hypoxia. HIF-1α exerts detrimental effects on the immune system, characterized by unopposed pro-inflammation at the macrophages, dendritic cells, T cells, and complement levels resulting in cytokines' storm, which is linked to the poor outcomes of COVID-19. On the other hand, HIF-2α role is regulatory and largely opposes the actions mediated by HIF-1α. In view of this, inhibiting HIF-1α release or switching its production to HIF-2α by natural products such as resveratrol or by synthetic drugs, offer a good therapeutic strategy that can prevent COVID-19 worst outcome in infected patients. The approach of breaking the vicious circle between lung damage-induced hypoxia and HIF-1α pro-inflammatory stimulant through drugs is considered to be extremely promising as a therapeutic manner to combat further deterioration of COVID19 cases.

Single cell sequencing unraveling genetic basis of severe COVID19 in obesity.

COVID-19 has shown a substantial variation in the rate and severity by which it impacts different demographic groups. Specifically, it has shown a predilection towards obese patients as well as well as other vulnerable groups including predilection of males over females, old age over young age and black races over Caucasian ones. Single cell sequencing studies have highlighted the role of cell polarity and the co-expression of proteases, such as Furin, along with ACE2 in the genesis of coronavirus disease rather than exclusively link tissue involvement with ACE2 levels thought previously. It has also forged a connection between the genetic and immune cellular mechanisms underlying COVID infection and the inflammatory state of obese patients, offering a more accurate explanation as to why obese patients are at increased risk of poor COVID outcomes. These commonalities encompass macrophage phenotype switching, genetic expression switching, and overexpression of the pro-inflammatory cytokines, depletion of the regulatory cytokines, in situ T cell proliferation, and T cell exhaustion. These findings demonstrate the necessity of single cell sequencing as a rapid means to identify and treat those who are most likely to need hospital admission and intensive care, in the hopes of precision medicine. Furthermore, this study underlines the use of immune modulators such as Leptin sensitizers, rather than immune suppressors as anti-inflammation therapies to switch the inflammatory response from a drastic immunological type 1 response to a beneficial type 2 effective one.

The potential use of ABO blood group system for risk stratification of COVID-19.

ABO blood groups is a cheap and affordable test that can be immediately retrieved from COVID-19 patients at the diagnosis. There is increasing evidence that non-O blood groups have both higher susceptibility and higher severity of COVID-19 infections. The reason behind such relationship seems elusive. Regarding susceptibility, Non-O individuals have Anti-A antibodies which can prevent viral entry across ACE-2 receptors, moreover, Non-O individuals are at higher risk of autoimmunity, hypercoagulable state, and dysbiosis resulting in an augmented tendency for vascular inflammatory sequelae of COVID-19. We can conclude, on the diagnostic level, that ABO blood groups can be potentially used for risk stratification of affected COVID-19 patients, to anticipate the deterioration of patients at higher risk for complications. On a therapeutic level, plasma from normal O blood group individuals might potentially replace the use of convalescent serum for the treatment of COVID-19.

Is it infection or rather vascular inflammation? Game-changer insights and recommendations from patterns of multi-organ involvement and affected subgroups in COVID-19.

Coronavirus disease 2019 (COVID-19) is a serious illness that has rapidly spread throughout the globe. The seriousness of complications puts significant pressures on hospital resources, especially the availability of ICU and ventilators. Current evidence suggests that COVID-19 pathogenesis majorly involves microvascular injury induced by hypercytokinemia, namely interleukin 6 (IL-6). We recount the suggested inflammatory pathway for COVID-19 and its effects on various organ systems, including respiratory, cardiac, hematologic, reproductive, and nervous organ systems, as well examine the role of hypercytokinemia in the at-risk geriatric and obesity subgroups with upregulated cytokines' profile. In view of these findings, we strongly encourage the conduction of prospective studies to determine the baseline levels of IL-6 in infected patients, which can predict a negative outcome in COVID-19 cases, with subsequent early administration of IL-6 inhibitors, to decrease the need for ICU admission and the pressure on healthcare systems. Video abstract: http://links.lww.com/CAEN/A24.

A multicenter consensus: A role of furin in the endothelial tropism in obese patients with COVID-19 infection.

Furin, a cleavage enzyme, is increasingly recognized in the pathogenesis of metabolic syndrome. Its cleavage action is an essential activation step for the endothelial pathogenicity of several viruses including SARS-CoV-2. This Furin-mediated endothelial tropism seems to underlie the multi-organ system involvement of COVID-19; which is a feature that was not recognized in the older versions of coronaviridae. Obese and diabetic patients, males, and the elderly, have increased serum levels of Furin, with its increased cellular activity; this might explain why these subgroups are at an increased risk of COVID-19 related complications and deaths. In contrast, smoking decreases cellular levels of Furin, this finding may be at the origin of the decreased severity of COVID-19 in smokers. Chinese herbal derived luteolin is suggested to be putative Furin inhibitor, with previous success against Dengue Fever. Additionally, Furin intracellular levels are largely dependent on concentration of intracellular ions, notably sodium, potassium, and magnesium. Consequently, the use of ion channel inhibitors, such as Calcium Channel blockers or Potassium Channel blockers, can prevent cellular transfection early in the course of the illness. Nicotine patches and Colchicine have also been suggested as potential therapies due to Furin mediated inhibition of COVID-19.

Possible molecular and paracrine involvement underlying the pathogenesis of COVID-19 cardiovascular complications.

Coronavirus disease 2019 (COVID-19) has been declared a pandemic on 11 March 2020 by the WHO. Despite being mainly a respiratory virus, cardiac complications have been described. These range from sudden cardiac death to subtle diastolic dysfunction after recovery from COVID-19. The commonest cardiac presentation to date is acute heart failure resulting from biventricular or left ventricular hypokinesis and elevation of cardiac troponins. It has been shown that COVID-19 downregulates angiotensin-converting enzyme-2, which has protective effects on the endothelium and cardiomyocytes. It has also been proven that COVID-19 induces a state of hypercytokinaemia, some cytokines such as interleukin-1 and interleukin-6 have an injurious effect on the myocardium and endothelium, respectively. Such pathogenic mechanisms might play a crucial role in induction of cardiomyocyte injury and impaired myocardial perfusion probably through coronary endothelial dysfunction. The understanding and linking of such mechanisms might help in tailoring drug repurposing for treatment or prophylaxis of COVID-19 cardiovascular complications.