Prevalence of comorbidities and symptoms stratified by severity of illness amongst adult patients with COVID-19: a systematic review

Quercetin inhibits SARS-CoV-2 infection and prevents syncytium formation by cells co-expressing the viral spike protein and human ACE2

BACKGROUND

Several in silico studies have determined that quercetin, a plant flavonol, could bind with strong affinity and low free energy to SARS-CoV-2 proteins involved in viral entry and replication, suggesting it could block infection of human cells by the virus. In the present study, we examined the ex vivo ability of quercetin to inhibit of SARS-CoV-2 replication and explored the mechanisms of this inhibition.

METHODS

Green monkey kidney Vero E6 cells and in human colon carcinoma Caco-2 cells were infected with SARS-CoV-2 and incubated in presence of quercetin; the amount of replicated viral RNA was measured in spent media by RT-qPCR. Since the formation of syncytia is a mechanism of SARS-CoV-2 propagation, a syncytialization model was set up using human embryonic kidney HEK293 co-expressing SARS-CoV-2 Spike (S) protein and human angiotensin converting enzyme 2 (ACE2), [HEK293(S + ACE2) cells], to assess the effect of quercetin on this cytopathic event by microscopic imaging and protein immunoblotting.

RESULTS

Quercetin inhibited SARS-CoV-2 replication in Vero E6 cells and Caco-2 cells in a concentration-dependent manner with a half inhibitory concentration (IC50) of 166.6 and 145.2 µM, respectively. It also inhibited syncytialization of HEK293(S + ACE2) cells with an IC50 of 156.7 µM. Spike and ACE2 co-expression was associated with decreased expression, increased proteolytic processing of the S protein, and diminished production of the fusogenic S2' fragment of S. Furin, a proposed protease for this processing, was inhibited by quercetin in vitro with an IC50 of 116 µM.

CONCLUSION

These findings suggest that at low 3-digit micromolar concentrations of quercetin could impair SARS-CoV-2 infection of human cells partly by blocking the fusion process that promotes its propagation.

Liver injury in COVID-19 patients with non-alcoholic fatty liver disease: an update

The coronavirus disease 2019 (COVID-19) pandemic has revolutionized the priorities of the medical society worldwide. Although most patients infected with SARS-CoV-2 exhibit respiratory symptoms, other organs may also be involved, including the liver, often resulting in liver injury. Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and its prevalence is expected to increase together with the epidemics of type 2 diabetes and obesity. Data about liver injury during COVID-19 are numerous, while overviews of this infection in patients with NAFLD, both in terms of respiratory and liver, are emerging. In this review, we summarise the current research focusing on COVID-19 in NAFLD patients and discuss the association between liver injury in COVID-19 subjects and non-alcoholic fatty liver disease.

In Vitro Evidence of Statins’ Protective Role against COVID-19 Hallmarks

Despite the progressions in COVID-19 understanding, the optimization of patient-specific therapies remains a challenge. Statins, the most widely prescribed lipid-lowering drugs, received considerable attention due to their pleiotropic effects, encompassing lipid metabolism control and immunomodulatory and anti-thrombotic effects. In COVID-19 patients, statins improve clinical outcomes, reducing Intensive Care Unit admission, the onset of ARDS, and in-hospital death. However, the safety of statins in COVID-19 patients has been debated, mainly for statins’ ability to induce the expression of the ACE2 receptor, the main entry route of SARS-CoV-2. Unfortunately, the dynamic of statins’ mechanism in COVID-19 disease and prevention remains elusive. Using different in vitro models expressing different levels of ACE2 receptor, we investigated the role of lipophilic and hydrophilic statins on ACE2 receptor expression and subcellular localization. We demonstrated that the statin-mediated increase of ACE2 receptor expression does not necessarily coincide with its localization in lipid rafts domains, particularly after treatments with the lipophilic atorvastatin that disrupt lipid rafts’ integrity. Through a proteomic array, we analyzed the cytokine patterns demonstrating that statins inhibit the release of cytokines and factors involved in mild to severe COVID-19 cases. The results obtained provide additional information to dissect the mechanism underlying the protective effects of statin use in COVID-19.

Usefulness of C2HEST Score in Predicting Clinical Outcomes of COVID-19 in Heart Failure and Non-Heart-Failure Cohorts

Background: Patients with heart failure represent a vulnerable population for COVID-19 and are prone to having worse prognoses and higher fatality rates. Still, the clinical course of the infection is dynamic, and complication occurrence in particular in patients with heart failure is fairly unpredictable. Considering that individual components of the C2HEST (C2: Coronary Artery Diseases (CAD)/Chronic obstructive pulmonary disease (COPD); H: Hypertension; E: Elderly (Age ≥ 75); S: Systolic HF; T: Thyroid disease) are parallel to COVID-19 mortality risk factors, we evaluate the predictive value of C2HEST score in patients with heart failure (HF) Material and Methods: The retrospective medical data analysis of 2184 COVID-19 patients hospitalized in the University Hospital in Wroclaw between February 2020 and June 2021 was the basis of the study. The measured outcomes included: in-hospital mortality, 3-month and 6-month all-cause-mortality, non-fatal end of hospitalization, and adverse in-hospital clinical events. Results: The heart failure cohort consists of 255 patients, while 1929 patients were assigned to the non-HF cohort. The in-hospital, 3-month, and 6-month mortality rates were highest in the HF cohort high-risk C2HEST stratum, reaching 38.61%, 53.96%, and 65.36%, respectively. In the non-HF cohort, in-hospital, 3-month, and 6-month mortalities were also highest in the high-risk C2HEST stratum and came to 26.39%, 52.78%, and 65.0%, respectively. An additional point in the C2HEST score increased the total death intensity in 10% of HF subjects (HR 1.100, 95% CI 0.968−1.250 p = 0.143) while in the non-HF cohort, the same value increased by 62.3% (HR 1.623, 95% CI 1.518−1.734 p < 0.0001). Conclusions: The C2HEST score risk in the HF cohort failed to show discriminatory performance in terms of mortality and other clinical adverse outcomes during hospitalization. C2HEST score in the non-HF cohort showed significantly better performance in terms of predicting in-hospital and 6-month mortality and other non-fatal clinical outcomes such as cardiovascular events (myocardial injury, acute heart failure, myocardial infarction, cardiogenic shock), pneumonia, sepsis, and acute renal injury.