Vitamin D attenuates COVID-19 complications via modulation of proinflammatory cytokines, antiviral proteins, and autophagy

Macrophages in CRSwNP: Do they deserve more attention?

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.

The Distinct Regulation of the Vitamin D and Aryl Hydrocarbon Receptors in COVID-19

(1) Background: SARS-CoV-2 affects several immune pathways, including the vitamin D (VDR) and the aryl hydrocarbon receptor pathways (AhR). The aim of the study was the evaluation of the VDR and AhR pathways in the blood of COVID-19 patients with regard to the severity of disease. (2) Methods: Observational, single-center, case-control design. A total of 240 samples were selected for exploration. Patients who tested negative for SARS-CoV-2 but suffered from other respiratory infections (ORIs) served as a control group. (3) Results: VDR-specific mRNA in the blood of patients with mild symptoms (131.2 ± 198.6) was significantly upregulated relative to the VDR expression of the ORI group (23.24 ± 42.60; p < 0.0001); however, VDR expression of critically ill patients showed an impaired upregulation (54.73 ± 68.34; p < 0.001). CYP27B1 expression was not significantly regulated during SARS-CoV-2 infection. There was a downregulation of VDR and CYP27B1 compared to survivors. There was no significant difference in 25(OH)-vitamin D3 levels between critically ill patients with regard to survival (24.3 ± 9.4 vs. 27.1 ± 11.3; p = 0.433). (4) Conclusion: The VDR and AhR pathways are distinctively regulated in patients suffering from COVID-19 depending on the severity of disease. A combination treatment of antiviral drugs and vitamin D substitution should be evaluated for potentially improved prognosis in COVID-19.

Exploring demographical, clinical, and dietary determinants of vitamin D deficiency among adults in Douala, Cameroon during the COVID-19 era

Background and aim

Vitamin D deficiency (VDD) is a global public health problem in African populations. This study aimed at determining the prevalence, characteristics, and determinants of VDD in the era of SARS-CoV-2/COVID-19. This study was conducted from January to September 2022 in seven health facilities in Douala, Cameroon.

Methods

A structured, pre-tested questionnaire was administered to each participant to collect participants' information. Molecular detection of the SARS-CoV-2 genome was done. A serum level of 25-hydroxyvitamin D < 20 ng/mL was used to diagnose VDD.

Results

A total of 420 participants were included in the study. A Serum levels of 25(OH) vitamin D were reduced in SARS-CoV-2 (+) patients as compared to SARS-CoV-2 (-) patients (21.69 ± 5.64 ng/mL vs 42.09 ± 20.03 ng/mL, p < 0.0001). The overall prevalence of VDD was 10.2 %. SARS-CoV-2 (+) individuals had nearly two times more risk of being VDD compared to SARS-CoV-2 (-) individuals (aRR = 1.81, p < 0.0001). The risk of VDD was reduced by 46 % and 71 % in those consuming cocoa bean or powder regularly (aRR = 0.54, p = 0.03) and rarely (aRR = 0.29, p = 0.02) as compared to those never consuming it. Likewise, the risk of VDD was reduced by 59 % and 78 % in those consuming sardine fish regularly (aRR = 0.47, p = 0.002) and rarely (aRR = 0.22, p = 0.03). Overall, the association between VDD and SARS-CoV-2 infection was consistent, i.e., reduced risk of VDD in SARS-CoV-2 (-) individuals, after stratification for confounding variables.

Conclusion

This study outlined a high burden of VDD, a strong link between VDD and SARS-CoV-2, and suggests the possible utility of vitamin D supplementation for COVID-19 patients in Cameroon.

Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy

Nearly four years after its first appearance, and having gone from pandemic to endemic, the SARS-CoV-2 remains out of control globally. The purpose of this study was to evaluate the clinical efficacy of vitamin D (VD) in COVID-19 and long COVID-19, explain the discrepancy in clinical outcomes and highlight the potential impact of metformin on VD efficacy in recent articles. Articles from January 2022 to August 2023 were selected for this review. The objective of this study was achieved by reviewing, analyzing, and discussing articles demonstrating (1) the mechanism of action of VD (2) observational or randomized clinical trials (RCTs) that support or not the beneficial clinical effects of VD in COVID-19 or long COVID. (3) genetic and non-genetic reasons for the variation in the effects of VD. Articles were collected from electronic databases such as PubMed, Scopus, MEDLINE, Google Scholar, Egyptian Knowledge Bank, Science Direct, and Cochrane Database of Systematic Reviews. Twenty three studies conducted in vitro or in animal models indicated that VD may act in COVID-19 through protecting the respiratory system by antimicrobial peptide cathelicidins, reducing lung inflammation, regulating innate and adaptive immune functions and up regulation of autophagy gene activity. Our review identified 58 clinical studies that met the criteria. The number of publications supporting a beneficial clinical activity of VD in treating COVID-19 was 49 (86%), including 12 meta-analyses. Although the total patients included in all articles was 14,071,273, patients included in publications supporting a beneficial role of VD in COVID-19 were 14,029,411 (99.7%). Collectively, extensive observational studies indicated a decisive relationship between low VD levels and the severity of COVID-19 and mortality outcomes. Importantly, evidence from intervention studies has demonstrated the effectiveness of VD supplements in treating COVID-19. Furthermore, the results of 4 observational studies supported the beneficial role of VD in alleviating symptoms of long COVID-19 disease. However, eight RCTs and one meta-analysis of RCTs may contain low-grade evidence against a beneficial role of VD in COVID-19. Twenty-five articles have addressed the association between VDR and DBP genetic polymorphisms and treatment failure of VD in COVID-19. Impaired VDR signaling may underlie the variability of VD effects as non-genetic mechanisms. Interestingly, in recent studies, metformin has a beneficial therapeutic role in COVID-19 and long COVID-19, possibly by improving AMPK signaling of the VDR and enhancing the efficacy of the VD. In conclusion, evidence has been significantly strengthened over the past 18 months, with several meta-analyses and RCTs reporting conclusive beneficial effects of VD supplementation against COVID-19 and highlighting metformin to improve VDR sensitivity and efficacy in treating COVID-19 and long COVID-19.

The effect of macronutrient and micronutrient supplements on COVID-19: an umbrella review

BACKGROUND AND AIMS

A healthy diet play an important role in the prevention and even treatment of various diseases. Proper nutrition plays an important role in boosting of immune system. These include the consumption of macronutrients such as proteins, lipids, carbohydrates, and also micronutrients including vitamins. Here, we aimed to systematically review the effects of macronutrients and micronutrients on the prevention and treatment of COVID-19.

METHODS

We searched the databases of PubMed, Scopus, Embase, and Web of Science on December 23, 2023. The records were downloaded into an EndNote file, the duplicates were removed, and the studies underwent a two-phase screening process based on their title/abstracts and full texts. The included articles were screened and underwent inclusion and exclusion criteria. We included the English systematic reviews and meta-analyses that concurred with the aim of our study. The selected articles were assessed by Cochrane's Risk of Bias in Systematic Reviews for the quality check. The data of the eligible studies were extracted in a pre-designed word table and were used for the qualitative synthesis.

RESULTS

A total of 28 reviews were included in this study. Most studies have shown that micronutrients are effective in morbidity and mortality controlling in viral respiratory infections such as COVID-19 but some studies have shown that micronutrients are sometimes not effective in controlling severity. On the other hand, calcifediol was by far the most successful agent in reducing intensive care needs and mortality between studies.

CONCLUSION

Individuals without malnutrition had a reduced risk of SARS-CoV-2 infection and severe disease. The administration of Vitamin D is effective in reducing the morbidity and mortality of COVID-19 patients. Patients with vitamin D deficiency were more prone to experience severe infection, and they were at higher risk of morbidities and mortality. Other micronutrients such as Vitamin A, Vitamin B, and Zinc also showed some benefits in patients with COVID-19. Vitamin C showed no efficacy in COVID-19 management even in intravenous form or in high doses.

Understanding the Immune-Endocrine Effects of Vitamin D in SARS-CoV-2 Infection: A Role in Protecting against Neurodamage

Calcitriol and hydroxyderivatives of lumisterol and tachisterol are secosteroid hormones with immunomodulatory and anti-inflammatory properties. Since the beginning of the COVID-19 pandemic, several studies have correlated deficient serum concentrations of vitamin D3 (calcifediol) with increased severity of the course of SARS-CoV-2 infection. Among systemic complications, subjective (anosmia, ageusia, depression, dizziness) and objective (ischemic stroke, meningoencephalitis, myelitis, seizures, Guillain-Barré syndrome) neurological symptoms have been reported in up to 80% of severe COVID-19 patients. In this narrative review, we will resume the pathophysiology of SARS-CoV-2 infection and the mechanisms of acute and chronic neurological damage. SARS-CoV-2 can disrupt the integrity of the endothelial cells of the blood-brain barrier (BBB) to enter the nervous central system. Invasion of pro-inflammatory cytokines and polarization of astrocytes and microglia cells always in a pro-inflammatory sense together with the pro-coagulative phenotype of cerebral endothelial cells in response to both SARS-CoV-2 and immune cells invasion (immunothrombosis) are the major drivers of neurodamage. Calcitriol and hydroxyderivatives of lumisterol and tachisterol could play an adjuvant role in neuroprotection through mitigation of neuroinflammation and protection of endothelial integrity of the BBB. Dedicated studies on this topic are currently lacking and are desirable to confirm the link between vitamin D3 and neuroprotection in COVID-19 patients.

Impact of Vitamin D on Immunopathology of Hashimoto's Thyroiditis: From Theory to Practice

Hashimoto's thyroiditis (HT) is a common autoimmune disease affecting the thyroid gland, characterized by lymphocytic infiltration, damage to thyroid cells, and hypothyroidism, and often requires lifetime treatment with levothyroxine. The disease has a complex etiology, with genetic and environmental factors contributing to its development. Vitamin D deficiency has been linked to a higher prevalence of thyroid autoimmunity in certain populations, including children, adolescents, and obese individuals. Moreover, vitamin D supplementation has shown promise in reducing antithyroid antibody levels, improving thyroid function, and improving other markers of autoimmunity, such as cytokines, e.g., IP10, TNF-α, and IL-10, and the ratio of T-cell subsets, such as Th17 and Tr1. Studies suggest that by impacting various immunological mechanisms, vitamin D may help control autoimmunity and improve thyroid function and, potentially, clinical outcomes of HT patients. The article discusses the potential impact of vitamin D on various immune pathways in HT. Overall, current evidence supports the potential role of vitamin D in the prevention and management of HT, although further studies are needed to fully understand its mechanisms of action and potential therapeutic benefits.

A Narrative Review on the Potential Role of Vitamin D3 in the Prevention, Protection, and Disease Mitigation of Acute and Long COVID-19

PURPOSE OF REVIEW

The coronavirus disease 2019 (COVID-19) pandemic has challenged global health systems and economies from January 2020. COVID-19 caused by the infectious severe acute respiratory syndrome coronavirus (SARS-CoV-2) has acute respiratory and cardiometabolic symptoms that can be severe and lethal. Long-term physiological and psychological symptoms, known as long COVID-19, persist affecting multiple organ systems. While vaccinations support the fight against SARS-CoV-2, other effective mechanisms of population protection should exist given the presence of yet unvaccinated and at-risk vulnerable groups, global disease comorbidities, and short-lived vaccine responses. The review proposes vitamin D₃ as a plausible molecule for prevention, protection, and disease mitigation of acute and long COVID-19.

RECENT FINDINGS

Epidemiological studies have shown that individuals who were deficient in vitamin D₃ had worse COVID-19 health outcomes and mortality rates. Higher doses of vitamin D₃ supplementation may improve health and survivorship in individuals of various age groups, comorbidities, and severity of disease symptoms. Vitamin D₃'s biological effects can provide protection and repair in multiple organ systems affected by SARS-CoV-2. Vitamin D₃ supplementation can potentially support disease-mitigation in acute and long COVID-19.

The association between vitamin D intake with inflammatory and biochemical indices and mortality in critically ill patients with COVID-19: A case-control study

BACKGROUND

The coronavirus disease-2019 (COVID-19) has become a worldwide health issue with widespread hospitalization and dependence on the intensive care unit (ICU). Vitamin D has a key role in modulating immune cells and modulating the inflammatory responses. This study aimed to investigate the association of vitamin D supplementation with inflammatory, biochemical, and mortality indices in critically ill patients with COVID-19.

METHODS

This case-control study was conducted on critically ill COVID-19 patients hospitalized in the ICU including the survived >30 day patients as the case group and dead patients as the control group. The status of vitamin D supplementation and inflammatory and biochemical indices of the patients were retrieved from the medical records. Logistic regression method was used to assess the association between 30 days survival and vitamin D supplement intake.

RESULTS

Compared to the group of COVID-19 patients who died in <30 day, the survived patients had a lower eosinophile level (2.2 ± 0.5 vs. 6 ± 0.0, p < .001) and higher vitamin D supplementation duration (9 ± 4.4 vs. 3.3 ± 1.9 day, p = .001). Vitamin D supplementation had a positive association with survival in COVID-19 patients (OR: 1.98, 95% CI: 1.15-3.40, p < .05). The association remained significant after adjustments fot age, sex, underlying diseases, and smoking.

CONCLUSION

Vitamin D supplementation in critically ill patients with COVID-19 has the potential to increase survivability within the first 30 days of hospitalization.

The Impact of Vitamin D Levels on Clinical Manifestations of Multisystem Inflammatory Syndrome in Children: A Cross-Sectional Study

BACKGROUND

Hyperinflammatory response that resembles Kawasaki disease may develop in children after COVID-19 disease, and it is called multisystem inflammatory syndrome in children. The cause of MIS-C is dysregulated innate immune response and a subsequent cytokine storm that results in endothelial damage. It has been determined that low levels of serum 25(OH)D increase the risk of developing immune-related diseases and disorders.

METHODS

To determine the incidence of hypovitaminosis D, and a possible correlation between 25(OH)D levels and the clinical severity of MIS-C, 21 patients hospitalized in the University Hospital of Split due to MIS-C were evaluated.

RESULTS

Hypovitaminosis D was detected in 95% of MIS-C patients. We found a significant relationship between the severity of MIS-C and 25(OH)D levels, as patients with more severe MIS-C had lower 25(OH)D. MIS-C patients with lower vitamin D levels had worse systolic and diastolic function of the left ventricle according to echocardiograms. There was no relationship between 25(OH)D levels and the tested laboratory inflammatory and cardiac markers.

CONCLUSION

Hypovitaminosis D is very common in children with MIS-C and influences the severity of the disease. VD could be a new potential biomarker in MIS-C, and VD replacement therapy should be considered early on in the treatment of MIS-C.

Severity of COVID-19 patients with coexistence of asthma and vitamin D deficiency

Coronavirus disease 2019 (COVID-19)-driven global pandemic triggered innumerable health complications, imposing great challenges in managing other respiratory diseases like asthma. Furthermore, increases in the underlying inflammation involved in the fatality of COVID-19 have been linked with lack of vitamin D. In this research work, we intend to investigate the possible genetic linkage of asthma and vitamin D deficiency with the severity and fatality of COVID-19 using a network-based approach. We identified and analysed 41 and 14 differentially expressed genes (DEGs) of COVID-19 being common with asthma and vitamin D deficiency, respectively, through the comparative differential gene expression analysis and their footprints on signalling pathways. Gene set enrichment analysis for GO terms and signalling pathways reveals key biological activities, including inflammatory response-related pathways (e.g., cytokine- and chemokine-mediated signalling pathways, IL-17, and TNF signalling pathways). Besides, the Protein–Protein Interaction network analysis of those DEGs reveals hub proteins, some of which are reported as inflammatory antiviral interferon-stimulated biomarkers that potentially drive the cytokine storm leading to COVID-19 severity and fatality, and contributes in the early stage of viral replication, respectively. Moreover, the regulatory network analysis found these DEGs associated with antiviral and tumour inhibitory transcription factors and micro-RNAs. Finally, drug–target enrichment analysis yields tetradioxin, estradiol, arsenenous acid, and zinc, which have been reported to be effective in suppressing the pro-inflammatory cytokines production, and other respiratory tract infections. Our results yield shared biomarker-driven key hypotheses followed by network-based analytics, demystifying the mechanistic details of COVID-19 comorbidity of asthma and vitamin D deficiency with their potential therapeutic implications.

The Association between Serum Vitamin D Concentration and New Inflammatory Biomarkers-Systemic Inflammatory Index (SII) and Systemic Inflammatory Response (SIRI)-In Patients with Ischemic Heart Disease

The incidence of ischemic heart disease (IHD) increases every year. This cardiovascular disease has an inflammatory factor in its etiology due to different immune cells that influence atherogenesis. New inflammatory biomarkers—the Systemic Inflammatory Index (SII) and the Systemic Inflammatory Response (SIRI)—attempt to describe the pro- and anti-inflammatory balance and quantify the complex impact of the immune system on atherosclerosis, while vitamin D has a multidirectional impact on the human body, including the cardiovascular and immune systems. Hence, the objective of this research was to analyze the association between SII and SIRI and serum vitamin D concentrations in patients with IHD. A significant correlation was observed between SIRI and 25(OH)D in the whole group and between both biomarkers (SII and SIRI) and 25(OH)D in the group of patients with ACS but not in the group of patients with stable IHD. The role of vitamin D in IHD complications and its association with new inflammatory biomarkers requires further well-designed, large-scale research.

IFI44 is an immune evasion biomarker for SARS-CoV-2 and Staphylococcus aureus infection in patients with RA

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic of severe coronavirus disease 2019 (COVID-19). Staphylococcus aureus is one of the most common pathogenic bacteria in humans, rheumatoid arthritis (RA) is among the most prevalent autoimmune conditions. RA is a significant risk factor for SARS-CoV-2 and S. aureus infections, although the mechanism of RA and SARS-CoV-2 infection in conjunction with S. aureus infection has not been elucidated. The purpose of this study is to investigate the biomarkers and disease targets between RA and SARS-CoV-2 and S. aureus infections using bioinformatics analysis, to search for the molecular mechanisms of SARS-CoV-2 and S. aureus immune escape and potential drug targets in the RA population, and to provide new directions for further analysis and targeted development of clinical treatments.

Methods

The RA dataset (GSE93272) and the S. aureus bacteremia (SAB) dataset (GSE33341) were used to obtain differentially expressed gene sets, respectively, and the common differentially expressed genes (DEGs) were determined through the intersection. Functional enrichment analysis utilizing GO, KEGG, and ClueGO methods. The PPI network was created utilizing the STRING database, and the top 10 hub genes were identified and further examined for functional enrichment using Metascape and GeneMANIA. The top 10 hub genes were intersected with the SARS-CoV-2 gene pool to identify five hub genes shared by RA, COVID-19, and SAB, and functional enrichment analysis was conducted using Metascape and GeneMANIA. Using the NetworkAnalyst platform, TF-hub gene and miRNA-hub gene networks were built for these five hub genes. The hub gene was verified utilizing GSE17755, GSE55235, and GSE13670, and its effectiveness was assessed utilizing ROC curves. CIBERSORT was applied to examine immune cell infiltration and the link between the hub gene and immune cells.

Results

A total of 199 DEGs were extracted from the GSE93272 and GSE33341 datasets. KEGG analysis of enrichment pathways were NLR signaling pathway, cell membrane DNA sensing pathway, oxidative phosphorylation, and viral infection. Positive/negative regulation of the immune system, regulation of the interferon-I (IFN-I; IFN-α/β) pathway, and associated pathways of the immunological response to viruses were enriched in GO and ClueGO analyses. PPI network and Cytoscape platform identified the top 10 hub genes: RSAD2, IFIT3, GBP1, RTP4, IFI44, OAS1, IFI44L, ISG15, HERC5, and IFIT5. The pathways are mainly enriched in response to viral and bacterial infection, IFN signaling, and 1,25-dihydroxy vitamin D3. IFI44, OAS1, IFI44L, ISG15, and HERC5 are the five hub genes shared by RA, COVID-19, and SAB. The pathways are primarily enriched for response to viral and bacterial infections. The TF-hub gene network and miRNA-hub gene network identified YY1 as a key TF and hsa-mir-1-3p and hsa-mir-146a-5p as two important miRNAs related to IFI44. IFI44 was identified as a hub gene by validating GSE17755, GSE55235, and GSE13670. Immune cell infiltration analysis showed a strong positive correlation between activated dendritic cells and IFI44 expression.

Conclusions

IFI144 was discovered as a shared biomarker and disease target for RA, COVID-19, and SAB by this study. IFI44 negatively regulates the IFN signaling pathway to promote viral replication and bacterial proliferation and is an important molecular target for SARS-CoV-2 and S. aureus immune escape in RA. Dendritic cells play an important role in this process. 1,25-Dihydroxy vitamin D3 may be an important therapeutic agent in treating RA with SARS-CoV-2 and S. aureus infections.

Deciphering the Potential of Pre and Pro-Vitamin D of Mushrooms against Mpro and PLpro Proteases of COVID-19: An In Silico Approach

Vitamin D’s role in combating the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the virus causing COVID-19, has been established in unveiling viable inhibitors of COVID-19. The current study investigated the role of pre and pro-vitamin D bioactives from edible mushrooms against Mpro and PLpro proteases of SARS-CoV-2 by computational experiments. The bioactives of mushrooms, specifically ergosterol (provitamin D₂), 7-dehydrocholesterol (provitamin-D₃), 22,23-dihydroergocalciferol (provitamin-D₄), cholecalciferol (vitamin-D₃), and ergocalciferol (vitamin D₂) were screened against Mpro and PLpro. Molecular docking analyses of the generated bioactive protease complexes unravelled the differential docking energies, which ranged from −7.5 kcal/mol to −4.5 kcal/mol. Ergosterol exhibited the lowest binding energy (−7.5 kcal/mol) against Mpro and PLpro (−5.9 kcal/mol). The Molecular Mechanics Poisson–Boltzmann Surface Area (MMPBSA) and MD simulation analyses indicated that the generated complexes were stable, thus affirming the putative binding of the bioactives to viral proteases. Considering the pivotal role of vitamin D bioactives, their direct interactions against SARS-CoV-2 proteases highlight the promising role of bioactives present in mushrooms as potent nutraceuticals against COVID-19.

Progress in preclinical studies of macrophage autophagy in the regulation of ALI/ARDS

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with high morbidity and mortality that poses a major challenge in critical care medicine. The development of ALI/ARDS involves excessive inflammatory response, and macrophage autophagy plays an important role in regulating the inflammatory response in ALI/ARDS. In this paper, we review the effects of autophagy in regulating macrophage function, discuss the roles of macrophage autophagy in ALI/ARDS, and highlight drugs and other interventions that can modulate macrophage autophagy in ALI/ARDS to improve the understanding of the mechanism of macrophage autophagy in ALI/ARDS and provide new ideas and further research directions for the treatment of ALI/ARDS.

Factors Modulating COVID-19: A Mechanistic Understanding Based on the Adverse Outcome Pathway Framework

Addressing factors modulating COVID-19 is crucial since abundant clinical evidence shows that outcomes are markedly heterogeneous between patients. This requires identifying the factors and understanding how they mechanistically influence COVID-19. Here, we describe how eleven selected factors (age, sex, genetic factors, lipid disorders, heart failure, gut dysbiosis, diet, vitamin D deficiency, air pollution and exposure to chemicals) influence COVID-19 by applying the Adverse Outcome Pathway (AOP), which is well-established in regulatory toxicology. This framework aims to model the sequence of events leading to an adverse health outcome. Several linear AOPs depicting pathways from the binding of the virus to ACE2 up to clinical outcomes observed in COVID-19 have been developed and integrated into a network offering a unique overview of the mechanisms underlying the disease. As SARS-CoV-2 infectibility and ACE2 activity are the major starting points and inflammatory response is central in the development of COVID-19, we evaluated how those eleven intrinsic and extrinsic factors modulate those processes impacting clinical outcomes. Applying this AOP-aligned approach enables the identification of current knowledge gaps orientating for further research and allows to propose biomarkers to identify of high-risk patients. This approach also facilitates expertise synergy from different disciplines to address public health issues.

A correlational analysis of COVID-19 incidence and mortality and urban determinants of vitamin D status across the London boroughs

One of the biggest challenges of the COVID-19 pandemic is the heterogeneity in disease severity exhibited amongst patients. Among multiple factors, latest studies suggest vitamin D deficiency and pre-existing health conditions to be major contributors to death from COVID-19. It is known that certain urban form attributes can impact sun exposure and vitamin D synthesis. Also, long-term exposure to air pollution can play an independent role in vitamin D deficiency. We conducted a correlational analysis of urban form and air quality in relation to the demographics and COVID-19 incidence and mortality across 32 London boroughs between March 2020 and January 2021. We found total population, number of residents of Asian ethnicity, 4-year average PM₁₀ levels and road length to be positively correlated with COVID-19 cases and deaths. We also found percentage of households with access to total open space to be negatively correlated with COVID-19 deaths. Our findings link COVID-19 incidence and mortality across London with environmental variables linked to vitamin D status. Our study is entirely based on publicly available data and provides a reference framework for further research as more data are gathered and the syndemic dimension of COVID-19 becomes increasingly relevant in connection to health inequalities within large urban areas.

The effects of high dose vitamin D supplementation as a nutritional intervention strategy on biochemical and inflammatory factors in adults with COVID-19: Study protocol for a randomized controlled trial

Introduction: Low serum vitamin D has been shown to be a risk factor for Coronavirus 2019 (COVID-19). The aim of this study was to assess the effects of high dose vitamin D supplementation on hs-CRP, ESR and clinical outcomes, including duration of hospitalization, quality of life and New York Heart Association (NYHA) Functional Classification, in adults with COVID-19. Methods: This double-blind, randomized control trial will be conducted on patients with RT-PCR and/or chest CT scan diagnosis of COVID-19 admitted in Imam Reza Hospital, Mashhad, Iran. Participants will be randomized into control and intervention groups based on randomization sampling. The intervention group will receive soft gel containing 50,000 IU vitamin D on the first day followed by 10,000 IU/day through a supplement drop daily for 29 days. The control group will receive 1000 IU vitamin D daily through supplement drop and a placebo soft gel. All participants will undergo laboratory assessment including inflammatory markers, serum 25)OH)D, complete blood count (CBC), liver and renal profile, lipid profile and erythrocyte sedimentation rate (ESR) at baseline and at day 30. The mortality rate will be recorded in both groups. Results: Data will be presented using descriptive statistics. Comparison of changes in study parameters over the study period will be performed using analysis of covariance adjusting for possible confounders. Conclusions: The findings of this will provide evidence on the effects of high dose vitamin D supplementation on inflammatory markers in hospitalized COVID-19 patients.

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.