Elevated Interleukin-10 Levels in COVID-19: Potentiation of Pro-Inflammatory Responses or Impaired Anti-Inflammatory Action?

Mimicking Gene-Environment Interaction of Higher Altitude Dwellers by Intermittent Hypoxia Training: COVID-19 Preventive Strategies

Cyclooxygenase 2 (COX2) inhibitors have been demonstrated to protect against hypoxia pathogenesis in several investigations. It has also been utilized as an adjuvant therapy in the treatment of COVID-19. COX inhibitors, which have previously been shown to be effective in treating previous viral and malarial infections are strong candidates for improving the COVID-19 therapeutic doctrine. However, another COX inhibitor, ibuprofen, is linked to an increase in the angiotensin-converting enzyme 2 (ACE2), which could increase virus susceptibility. Hence, inhibiting COX2 via therapeutics might not always be protective and we need to investigate the downstream molecules that may be involved in hypoxia environment adaptation. Research has discovered that people who are accustomed to reduced oxygen levels at altitude may be protected against the harmful effects of COVID-19. It is important to highlight that the study's conclusions only applied to those who regularly lived at high altitudes; they did not apply to those who occasionally moved to higher altitudes but still lived at lower altitudes. COVID-19 appears to be more dangerous to individuals residing at lower altitudes. The downstream molecules in the (COX2) pathway have been shown to adapt in high-altitude dwellers, which may partially explain why these individuals have a lower prevalence of COVID-19 infection. More research is needed, however, to directly address COX2 expression in people living at higher altitudes. It is possible to mimic the gene-environment interaction of higher altitude people by intermittent hypoxia training. COX-2 adaptation resulting from hypoxic exposure at altitude or intermittent hypoxia exercise training (IHT) seems to have an important therapeutic function. Swimming, a type of IHT, was found to lower COX-2 protein production, a pro-inflammatory milieu transcription factor, while increasing the anti-inflammatory microenvironment. Furthermore, Intermittent Hypoxia Preconditioning (IHP) has been demonstrated in numerous clinical investigations to enhance patients' cardiopulmonary function, raise cardiorespiratory fitness, and increase tissues' and organs' tolerance to ischemia. Biochemical activities of IHP have also been reported as a feasible application strategy for IHP for the rehabilitation of COVID-19 patients. In this paper, we aim to highlight some of the most relevant shared genes implicated with COVID-19 pathogenesis and hypoxia. We hypothesize that COVID-19 pathogenesis and hypoxia share a similar mechanism that affects apoptosis, proliferation, the immune system, and metabolism. We also highlight the necessity of studying individuals who live at higher altitudes to emulate their gene-environment interactions and compare the findings with IHT. Finally, we propose COX2 as an upstream target for testing the effectiveness of IHT in preventing or minimizing the effects of COVID-19 and other oxygen-related pathological conditions in the future.

Levosimendan Increases Survival in a D-Galactosamine and Lipopolysaccharide Rat Model

Levosimendan, a calcium sensitizer, has an organ protective profile through the inhibition of inflammatory mediators and cytokines in critical conditions, such as heart failure, ischemia-reperfusion injury, and sepsis. The survival effect of levosimendan for acute liver failure has not been examined yet. Male Sprague-Dawley rats were examined in the D-galactosamine hydrochloride and lipopolysaccharide (GalN/LPS) model. Levosimendan was injected intraperitoneally before GalN/LPS treatment. Survival was monitored for 7 days. For biochemical analyses, liver and blood samples were collected from the rats at 1 and 8 h after GaIN/LPS treatment. The pretreatment of levosimendan at 4 mg/kg significantly increased survival in GalN/LPS rats. In the liver specimen, levosimendan significantly inhibited the activation of nuclear factor-κB (NF-κB) at 1 h, and significantly decreased the mRNA expression of inflammatory mediators, including inducible nitric oxide synthase and tumor necrosis factor-α (TNF-α), at 8 h. In serum, levosimendan decreased the levels of nitrite, a metabolite of nitric oxide, and TNF-α protein, as well as aspartate aminotransferase and alanine aminotransferase. These results indicated that Levosimendan ameliorated liver dysfunction and survival in acute liver failure model rats through the suppression of NF-κB activation.

Clinical and biochemical characteristics of people experiencing post-coronavirus disease 2019-related symptoms: A prospective follow-up investigation

Background

Post-acute coronavirus disease 2019 (COVID-19) syndrome, also known as long COVID, is a prolonged illness after the acute phase of COVID-19. Hospitalized patients were known to have persisting symptoms of fatigue, headache, dyspnea, and anosmia. There is a need to describe the characteristics of individuals with post-COVID-19 symptoms in comparison to the baseline characteristics.

Purpose

To investigate the clinical and biochemical characteristics of people who recovered from COVID-19 after 6 months of discharge from the hospital.

Methods

This was a prospective follow-up investigation of hospitalized and discharged COVID-19 patients. Adult patients admitted to King Saud University Medical City, Riyadh, Saudi Arabia, with laboratory-confirmed COVID-19 and discharged were recruited. The baseline demographic information, comorbidities, vital signs and symptoms, laboratory parameters, COVID-19 therapy, and outcomes were collected from the medical records. Blood samples were collected for cytokines estimation. A detailed interview about signs and symptoms was undertaken during the follow-up.

Results

Half of the followed-up people reported experiencing at least one of the COVID-19-related symptoms. The mean blood pressure was found higher in follow-up. People with the symptoms were characterized by low lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without any post-COVID-19 symptoms. Cytokines IL-8, VEGF, and MCP-1 were higher in people with the most frequent symptoms.

Conclusion

People with post-COVID-19 symptoms were characterized by lower lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without symptoms. Individuals with the most frequent post-COVID-19 symptoms had higher baseline pro-inflammatory, chemotactic, and angiogenic cytokines.

The effect of ARVs on the MEKKK1 gene promoter, inflammatory cytokine expression and signalling in acute treated Jurkat T cells

ARVs alter the methylation status of the MEKKK1 gene promoter in acute treated Jurkat T cells with inflammatory outcomesInflammation is reduced in patients under going antiretroviral therapy; however the mechanism is not well understood. We investigated DNA methylation of the mitogen-activated protein kinase kinase kinase kinase 1 (MEKKK1) gene promoter in Jurkat T cells to determine whether the antiretroviral drugs, lamivudine, tenofovir disoproxil fumarate, dolutegravir, TLD (a combination of TDF, 3TC and DTG) and efavirenz modify the methylation status of the MEKKK1 gene - a known stimulus of inflammation.Acute antiretroviral treatments (24 h) were not cytotoxic to Jurkat T cells. MEKKK1 promoter hypomethylation occurred in cells treated with 5-aza-2'-deoxycytidine (Aza), TDF and 3TC, and MEKKK1 promoter hypermethylation occurred in cells treated with DTG; however, promoter DNA methylation of the MEKKK1 gene did not influence MEKKK1 gene expression; therefore, these drugs did not epigenetically regulate MEKKK1 and downstream signalling by promoter DNA methylation. Acute TLD and EFV treatments induced inflammation in Jurkat T cells by increasing MEKKK1, MAPK/ERK and NFκB expression, and activating tumour necrosis factor-α (TNF-α) expression. ARVs decreased IL-10 gene expression, showing no anti-inflammatory activity.The data shows that the inflammation caused by ARVs is not related to the methylation status of MEKKK1 gene promoter and suggests an alternative stimulus via post-transcriptional/post-translational modifications may activate the canonical MEKKK1/NFκB pathway that leads to inflammation. Finally, an increase in NFκB activity and pro-inflammatory cytokine activation seemed to occur via the MAPK/ERK pathway following ARV treatments in Jurkat T cells.

Cytokine Profiling in Different SARS-CoV-2 Genetic Variants

This study is a successor of our previous work concerning changes in the chemokine profile in infection that are associated with different SARS-CoV-2 genetic variants. The goal of our study was to take into account both the virus and the host immune system by assessing concentrations of cytokines in patients infected with different SARS-CoV-2 variants (ancestral Wuhan strain, Alpha, Delta and Omicron). Our study was performed on 340 biological samples taken from COVID-19 patients and healthy donors in the timespan between May 2020 and April 2022. We performed genotyping of the virus in nasopharyngeal swabs, which was followed by assessment of cytokines' concentration in blood plasma. We noted that out of nearly 30 cytokines, only four showed stable elevation independently of the variant (IL-6, IL-10, IL-18 and IL-27), and we believe them to be 'constant' markers for COVID-19 infection. Cytokines that were studied as potential biomarkers lose their diagnostic value as the virus evolves, and the specter of potential targets for predictive models is narrowing. So far, only four cytokines (IL-6, IL-10, IL-18, and IL-27) showed a consistent rise in concentrations independently of the genetic variant of the virus. Although we believe our findings to be of scientific interest, we still consider them inconclusive; further investigation and comparison of immune responses to different variants of SARS-CoV-2 is required.

Alterations in the Kynurenine-Tryptophan Pathway and Lipid Dysregulation Are Preserved Features of COVID-19 in Hemodialysis

Coronavirus disease 2019 (COVID-19)-induced metabolic alterations have been proposed as a source for prognostic biomarkers and may harbor potential for therapeutic exploitation. However, the metabolic impact of COVID-19 in hemodialysis (HD), a setting of profound a priori alterations, remains unstudied. To evaluate potential COVID-19 biomarkers in end-stage kidney disease (CKD G5), we analyzed the plasma metabolites in different COVID-19 stages in patients with or without HD. We recruited 18 and 9 asymptomatic and mild, 11 and 11 moderate, 2 and 13 severely affected, and 10 and 6 uninfected HD and non-HD patients, respectively. Plasma samples were taken at the time of diagnosis and/or upon admission to the hospital and analyzed by targeted metabolomics and cytokine/chemokine profiling. Targeted metabolomics confirmed stage-dependent alterations of the metabolome in non-HD patients with COVID-19, which were less pronounced in HD patients. Elevated kynurenine levels and lipid dysregulation, shown by an increase in circulating free fatty acids and a decrease in lysophospholipids, could distinguish patients with moderate COVID-19 from non-infected individuals in both groups. Kynurenine and lipid alterations were also associated with ICAM-1 and IL-15 levels in HD and non-HD patients. Our findings support the kynurenine pathway and plasma lipids as universal biomarkers of moderate and severe COVID-19 independent of kidney function.

Albumin Infusion May Improve the Prognosis of Critical COVID-19 Patients with Hypoalbuminemia in the Intensive Care Unit: A Retrospective Cohort Study

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused enormous mortality worldwide. Low albumin level is a risk factor for increasing mortality among patients in the intensive care unit (ICU). This study investigated the effect of albumin infusion on critical COVID-19 patients with hypoalbuminemia.

Methods

A total of 114 COVID-19 ICU patients with hypoalbuminemia were recruited from Wuhan Leishenshan Hospital and Zhongnan Hospital of Wuhan University. Clinical features and laboratory variables were collected through electronic medical records. The cohorts were divided into two groups: albumin infusion and non-albumin infusion. Propensity-matched analysis was used to compare patients who received albumin to controls. Statistical analyses were used to investigate the survival time and inflammation-related blood biomarkers between groups.

Results

Lactate dehydrogenase, interleukin (IL)-6, IL-2 receptor, and IL-8 levels were significantly downregulated in the albumin infusion group. Significant upregulations of lymphocyte counts and IL-10 were found in the albumin infusion group. There was a negative association between albumin level and D-dimer or procalcitonin levels after treatment. The albumin infusion group had a significantly longer survival time and shorter hospitalization time than control patients. Notably, a 1g increase in albumin level reduced the risk of death by approximately 7.3% after adjusting for age and sex. Patients with increased albumin levels after treatment had better prognoses than those without.

Conclusion

Albumin administration can regulate COVID-19-related biomarkers and reduce the risk of death in critical patients with hypoalbuminemia. Clinicians should pay more attention to these risk factors. Targeted clinical interventions should be implemented to minimize the negative impacts of hypoalbuminemia and improve disease outcomes.

Biomarkers for differentiation of coronavirus disease 2019 or extracorporeal membrane oxygenation related inflammation and bacterial/fungal infections in critically ill patients: A prospective observational study

Secondary infections in coronavirus disease 2019 (COVID-19) patients are difficult to distinguish from inflammation associated with COVID-19 and/or extracorporeal membrane oxygenation (ECMO). Therefore, highly specific and sensitive biomarkers are needed to identify patients in whom antimicrobial therapy can be safely withheld. In this prospective monocentric study, 66 COVID-19 patients admitted to the intensive care unit (ICU) for ECMO evaluation were included. A total of 46 (70%) patients with secondary infections were identified by using broad microbiological and virological panels and standardized diagnostic criteria. Various laboratory parameters including C-reactive protein (CRP), interleukin (IL)-6, procalcitonin (PCT), and IL-10 were determined at time of study inclusion. The best test performance for differentiating bacterial/fungal secondary infections and COVID-19 and/or ECMO associated inflammation was achieved by IL-10 (ROC-AUC 0.84) and a multivariant step-wise regression model including CRP, IL-6, PCT, and IL-10 (ROC-AUC 0.93). Data obtained in the present study highlights the use of IL-10 to differentiate secondary bacterial/fungal infections from COVID-19 and/or ECMO associated inflammation in severely ill COVID-19 patients.

Cognitive dysfunction associated with COVID-19: Prognostic role of circulating biomarkers and microRNAs

COVID-19 is renowned as a multi-organ disease having subacute and long-term effects with a broad spectrum of clinical manifestations. The evolving scientific and clinical evidence demonstrates that the frequency of cognitive impairment after COVID-19 is high and it is crucial to explore more clinical research and implement proper diagnostic and treatment strategies. Several central nervous system complications have been reported as comorbidities of COVID-19. The changes in cognitive function associated with neurodegenerative diseases develop slowly over time and are only diagnosed at an already advanced stage of molecular pathology. Hence, understanding the common links between COVID-19 and neurodegenerative diseases will broaden our knowledge and help in strategizing prognostic and therapeutic approaches. The present review focuses on the diverse neurodegenerative changes associated with COVID-19 and will highlight the importance of major circulating biomarkers and microRNAs (miRNAs) associated with the disease progression and severity. The literature analysis showed that major proteins associated with central nervous system function, such as Glial fibrillary acidic protein, neurofilament light chain, p-tau 181, Ubiquitin C-terminal hydrolase L1, S100 calcium-binding protein B, Neuron-specific enolase and various inflammatory cytokines, were significantly altered in COVID-19 patients. Furthermore, among various miRNAs that are having pivotal roles in various neurodegenerative diseases, miR-146a, miR-155, Let-7b, miR-31, miR-16 and miR-21 have shown significant dysregulation in COVID-19 patients. Thus the review consolidates the important findings from the numerous studies to unravel the underlying mechanism of neurological sequelae in COVID-19 and the possible association of circulatory biomarkers, which may serve as prognostic predictors and therapeutic targets in future research.

COVID-19, obesity, and immune response 2 years after the pandemic: A timeline of scientific advances

In the 2 years since the COVID-19 pandemic was officially declared, science has made considerable strides in understanding the disease's pathophysiology, pharmacological treatments, immune response, and vaccination, but there is still much room for further advances, especially in comprehending its relationship with obesity. Science has not yet described the mechanisms that explain how obesity is directly associated with a poor prognosis. This paper gathers all published studies over the past 2 years that have described immune response, obesity, and COVID-19, a historical and chronological record for researchers and the general public alike. In summary, these studies describe how the cytokine/adipokine levels and inflammatory markers, such as the C-reactive protein, are associated with a higher body mass index in COVID-19-positive patients, suggesting that the inflammatory background and immune dysregulation in individuals with obesity may be expressed in the results and that adiposity may influence the immune response. The timeline presented here is a compilation of the results of 2 years of scientific inquiry, describing how the science has progressed, the principal findings, and the challenges ahead regarding SARS-CoV-2, COVID-19, and emerging variants, especially in patients with obesity.

Dectin-1 as a Potential Inflammatory Biomarker for Metabolic Inflammation in Adipose Tissue of Individuals with Obesity

In obesity, macrophage activation and infiltration in adipose tissue (AT) underlie chronic low-grade inflammation-induced insulin resistance. Although dectin-1 is primarily a pathogen recognition receptor and innate immune response modulator, its role in metabolic syndromes remains to be clarified. This study aimed to investigate the dectin-1 gene expression in subcutaneous AT in the context of obesity and associated inflammatory markers. Subcutaneous AT biopsies were collected from 59 nondiabetic (lean/overweight/obese) individuals. AT gene expression levels of dectin-1 and inflammatory markers were determined via real-time reverse transcriptase-quantitative polymerase chain reaction. Dectin-1 protein expression was assessed using immunohistochemistry. Plasma lipid profiles were measured by ELISA. AT dectin-1 transcripts and proteins were significantly elevated in obese as compared to lean individuals. AT dectin-1 transcripts correlated positively with body mass index and fat percentage (r ≥ 0.340, p ≤ 0.017). AT dectin-1 RNA levels correlated positively with clinical parameters, including plasma C-reactive protein and CCL5/RANTES, but negatively with that of adiponectin. The expression of dectin-1 transcripts was associated with that of various proinflammatory cytokines, chemokines, and their cognate receptors (r ≥ 0.300, p ≤ 0.05), but not with anti-inflammatory markers. Dectin-1 and members of the TLR signaling cascade were found to be significantly associated, suggesting an interplay between the two pathways. Dectin-1 expression was correlated with monocyte/macrophage markers, including CD16, CD68, CD86, and CD163, suggesting its monocytes/macrophage association in an adipose inflammatory microenvironment. Dectin-1 expression was independently predicted by CCR5, CCL20, TLR2, and MyD88. In conclusion, dectin-1 may be regarded as an AT biomarker of metabolic inflammation in obesity.

Plasma SARS-CoV-2 nucleocapsid antigen levels are associated with progression to severe disease in hospitalized COVID-19

BACKGROUND

Studies quantifying SARS-CoV-2 have focused on upper respiratory tract or plasma viral RNA with inconsistent association with clinical outcomes. The association between plasma viral antigen levels and clinical outcomes has not been previously studied. Our aim was to investigate the relationship between plasma SARS-CoV-2 nucleocapsid antigen (N-antigen) concentration and both markers of host response and clinical outcomes.

METHODS

SARS-CoV-2 N-antigen concentrations were measured in the first study plasma sample (D0), collected within 72 h of hospital admission, from 256 subjects admitted between March 2020 and August 2021 in a prospective observational cohort of hospitalized patients with COVID-19. The rank correlations between plasma N-antigen and plasma biomarkers of tissue damage, coagulation, and inflammation were assessed. Multiple ordinal regression was used to test the association between enrollment N-antigen plasma concentration and the primary outcome of clinical deterioration at one week as measured by a modified World Health Organization (WHO) ordinal scale. Multiple logistic regression was used to test the association between enrollment plasma N-antigen concentration and the secondary outcomes of ICU admission, mechanical ventilation at 28 days, and death at 28 days. The prognostic discrimination of an externally derived "high antigen" cutoff of N-antigen ≥ 1000 pg/mL was also tested.

RESULTS

N-antigen on D0 was detectable in 84% of study participants. Plasma N-antigen levels significantly correlated with RAGE (r = 0.61), IL-10 (r = 0.59), and IP-10 (r = 0.59, adjusted p = 0.01 for all correlations). For the primary outcome of clinical status at one week, each 500 pg/mL increase in plasma N-antigen level was associated with an adjusted OR of 1.05 (95% CI 1.03-1.08) for worse WHO ordinal status. D0 plasma N-antigen ≥ 1000 pg/mL was 77% sensitive and 59% specific (AUROC 0.68) with a positive predictive value of 23% and a negative predictive value of 93% for a worse WHO ordinal scale at day 7 compared to baseline. D0 N-antigen concentration was independently associated with ICU admission and 28-day mechanical ventilation, but not with death at 28 days.

CONCLUSIONS

Plasma N-antigen levels are readily measured and provide important insight into the pathogenesis and prognosis of COVID-19. The measurement of N-antigen levels early in-hospital course may improve risk stratification, especially for identifying patients who are unlikely to progress to severe disease.

Evaluation of the immunomodulatory effects of interleukin-10 on peripheral blood immune cells of COVID-19 patients: Implication for COVID-19 therapy

Objective

Several therapies with immune-modulatory functions have been proposed to reduce the overwhelmed inflammation associated with COVID-19. Here we investigated the impact of IL-10 in COVID-19, through the ex-vivo assessment of the effects of exogenous IL-10 on SARS-CoV-2-specific-response using a whole-blood platform.

Methods

Two cohorts were evaluated: in “study population A”, plasma levels of 27 immune factors were measured by a multiplex (Luminex) assay in 39 hospitalized “COVID-19 patients” and 29 “NO COVID-19 controls” all unvaccinated. In “study population B”, 29 COVID-19 patients and 30 NO COVID-19-Vaccinated Controls (NO COVID-19-VCs) were prospectively enrolled for the IL-10 study. Whole-blood was stimulated overnight with SARS-COV-2 antigens and then treated with IL-10. Plasma was collected and used for ELISA and multiplex assay. In parallel, whole-blood was stimulated and used for flow cytometry analysis.

Results

Baseline levels of several immune factors, including IL-10, were significantly elevated in COVID-19 patients compared with NO COVID-19 subjects in “study population A”. Among them, IL-2, FGF, IFN-γ, and MCP-1 reached their highest levels within the second week of infection and then decreased. To note that, MCP-1 levels remained significantly elevated compared with controls. IL-10, GM-CSF, and IL-6 increased later and showed an increasing trend over time. Moreover, exogenous addition of IL-10 significantly downregulated IFN-γ response and several other immune factors in both COVID-19 patients and NO COVID-19-VCs evaluated by ELISA and a multiplex analysis (Luminex) in “study population B”. Importantly, IL-10 did not affect cell survival, but decreased the frequencies of T-cells producing IFN-γ, TNF-α, and IL-2 (p<0.05) and down-modulated HLA-DR expression on CD8⁺ and NK cells.

Conclusion

This study provides important insights into immune modulating effects of IL-10 in COVID-19 and may provide valuable information regarding the further in vivo investigations.

Inflammatory pathways in COVID‐19: Mechanism and therapeutic interventions

The 2019 coronavirus disease (COVID‐19) pandemic has become a global crisis. In the immunopathogenesis of COVID‐19, SARS‐CoV‐2 infection induces an excessive inflammatory response in patients, causing an inflammatory cytokine storm in severe cases. Cytokine storm leads to acute respiratory distress syndrome, pulmonary and other multiorgan failure, which is an important cause of COVID‐19 progression and even death. Among them, activation of inflammatory pathways is a major factor in generating cytokine storms and causing dysregulated immune responses, which is closely related to the severity of viral infection. Therefore, elucidation of the inflammatory signaling pathway of SARS‐CoV‐2 is important in providing otential therapeutic targets and treatment strategies against COVID‐19. Here, we discuss the major inflammatory pathways in the pathogenesis of COVID‐19, including induction, function, and downstream signaling, as well as existing and potential interventions targeting these cytokines or related signaling pathways. We believe that a comprehensive understanding of the regulatory pathways of COVID‐19 immune dysregulation and inflammation will help develop better clinical therapy strategies to effectively control inflammatory diseases, such as COVID‐19.

Post-COVID-19 Parkinsonism and Parkinson’s Disease Pathogenesis: The Exosomal Cargo Hypothesis

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease after Alzheimer’s disease, globally. Dopaminergic neuron degeneration in substantia nigra pars compacta and aggregation of misfolded alpha-synuclein are the PD hallmarks, accompanied by motor and non-motor symptoms. Several viruses have been linked to the appearance of a post-infection parkinsonian phenotype. Coronavirus disease 2019 (COVID-19), caused by emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, has evolved from a novel pneumonia to a multifaceted syndrome with multiple clinical manifestations, among which neurological sequalae appear insidious and potentially long-lasting. Exosomes are extracellular nanovesicles bearing a complex cargo of active biomolecules and playing crucial roles in intercellular communication under pathophysiological conditions. Exosomes constitute a reliable route for misfolded protein transmission, contributing to PD pathogenesis and diagnosis. Herein, we summarize recent evidence suggesting that SARS-CoV-2 infection shares numerous clinical manifestations and inflammatory and molecular pathways with PD. We carry on hypothesizing that these similarities may be reflected in exosomal cargo modulated by the virus in correlation with disease severity. Travelling from the periphery to the brain, SARS-CoV-2-related exosomal cargo contains SARS-CoV-2 RNA, viral proteins, inflammatory mediators, and modified host proteins that could operate as promoters of neurodegenerative and neuroinflammatory cascades, potentially leading to a future parkinsonism and PD development.

Inflammatory mediators profile in patients hospitalized with COVID-19: A comparative study

Abnormal inflammatory mediator concentrations during SARS-CoV-2 infection may represent disease severity. We aimed to assess plasma inflammatory mediator concentrations in patients with SARS-CoV-2 in Addis Ababa, Ethiopia. In this study, 260 adults: 126 hospitalized patients with confirmed COVID-19 sorted into severity groups: severe (n=68) and mild or moderate (n=58), and 134 healthy controls were enrolled. We quantified 39 plasma inflammatory mediators using multiplex ELISA. Spearman rank correlation and Mann-Whitney U test were used to identify mechanistically coupled inflammatory mediators and compare disease severity. Compared to healthy controls, patients with COVID-19 had significantly higher levels of interleukins 1α, 2, 6, 7, 8, 10 and 15, C-reactive protein (CRP), serum amyloid A (SAA), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), IFN-γ-inducible protein-10 (IP-10, CXCL10), macrophage inflammatory protein-1 alpha (MIP-1α, CCL3), eotaxin-3 (CCL26), interferon-gamma (IFN-γ), tumor necrosis factor-α (TNF-α), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and fms-like tyrosine kinase 1 (Flt-1). Patients with severe COVID-19 had higher IL-10 and lower macrophage-derived chemokine (MDC, CCL22) compared to the mild or moderate group (P<0.05). In the receiver operating characteristic curve, SAA, IL-6 and CRP showed strong sensitivity and specificity in predicting the severity and prognosis of COVID-19. Greater age and higher CRP had a significant association with disease severity (P<0.05). Our findings reveal that CRP, SAA, VCAM-1, CXCL10, CCL22 and IL-10 levels are promising biomarkers for COVID-19 disease severity, suggesting that plasma inflammatory mediators could be used as warning indicators of COVID-19 severity, aid in COVID-19 prognosis and treatment.

A Real Pandora's Box in Pandemic Times: A Narrative Review on the Acute Cardiac Injury Due to COVID-19

The intricate relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the cardiovascular system is an extensively studied pandemic topic, as there is an ever-increasing amount of evidence that reports a high prevalence of acute cardiac injury in the context of viral infection. In patients with Coronavirus disease 2019, COVID-19, a significant increase in serum levels of cardiac troponin or other various biomarkers was observed, suggesting acute cardiac injury, thus predicting both a severe course of the disease and a poor outcome. Pathogenesis of acute cardiac injury is not yet completely elucidated, though several mechanisms are allegedly involved, such as a direct cardiomyocyte injury, oxygen supply-demand inequity caused by hypoxia, several active myocardial depressant factors during sepsis, and endothelial dysfunction due to the hyperinflammatory status. Moreover, the increased levels of plasma cytokines and catecholamines and a significantly enhanced prothrombotic environment may lead to the destabilization and rupture of atheroma plaques, subsequently triggering an acute coronary syndrome. In the present review, we focus on describing the epidemiology, pathogenesis, and role of biomarkers in the diagnosis and prognosis of patients with acute cardiac injury in the setting of the COVID-19 pandemic. We also explore some novel therapeutic strategies involving immunomodulatory therapy, as well as their role in preventing a severe form of the disease, with both the short-term outcome and the long-term cardiovascular sequelae being equally important in patients with SARS-CoV-2 induced acute cardiac injury.

Dengue and COVID-19: two sides of the same coin

BACKGROUND

Many countries in Asia and Latin America are currently facing a double burden of outbreaks due to dengue and COVID-19. Here we discuss the similarities and differences between the two infections so that lessons learnt so far from studying both infections will be helpful in further understanding their immunopathogenesis and to develop therapeutic interventions.

MAIN BODY

Although the entry routes of the SARS-CoV-2 and the dengue virus (DENV) are different, both infections result in a systemic infection, with some similar clinical presentations such as fever, headache, myalgia and gastrointestinal symptoms. However, while dengue is usually associated with a tendency to bleed, development of micro and macrothrombi is a hallmark of severe COVID-19. Apart from the initial similarities in the clinical presentation, there are further similarities between such as risk factors for development of severe illness, cytokine storms, endothelial dysfunction and multi-organ failure. Both infections are characterised by a delayed and impaired type I IFN response and a proinflammatory immune response. Furthermore, while high levels of potent neutralising antibodies are associated with protection, poorly neutralising and cross-reactive antibodies have been proposed to lead to immunopathology by different mechanisms, associated with an exaggerated plasmablast response. The virus specific T cell responses are also shown to be delayed in those who develop severe illness, while varying degrees of endothelial dysfunction leads to increased vascular permeability and coagulation abnormalities.

CONCLUSION

While there are many similarities between dengue and SARS-CoV-2 infection, there are also key differences especially in long-term disease sequelae. Therefore, it would be important to study the parallels between the immunopathogenesis of both infections for development of more effective vaccines and therapeutic interventions.

The Associations between Cytokine Levels, Kidney and Heart Function Biomarkers, and Expression Levels of Angiotensin-Converting Enzyme-2 and Neuropilin-1 in COVID-19 Patients

Background: Higher expression of angiotensin-converting enzyme-2 (ACE-2) in addition to neuropilin-1 (NRP-1) can lead to a cytokine storm which is correlated to higher mortality rate and contributes to the progression of renal diseases and the pathogenesis of coronary heart disease (CHD) in COVID-19 patients. Aim: We herein sought to examine correlations between cytokine levels, ACE-2 and NRP-1 expression, renal function biomarkers, and cardiac enzymes in COVID-19 patients. Patients and Methods: For the study, 50 healthy subjects and 100 COVID-19 patients were enrolled. Then, confirmed cases of COVID-19 were divided into two groups—those with moderate infection and those with severe infection—and compared to healthy controls. Serum creatinine, urea, CK-MB, LDH, troponin I, IL-1β, IL-4, IL-10, IL-17, and INF-γ levels were estimated. We also studied the gene expression for ACE-2 and NRP-1 in blood samples utilizing quantitative real-time polymerase chain reaction (qRT-PCR). Results: All COVID-19 patients demonstrated a significant increase in the levels of serum creatinine, urea, CK-MB, LDH, and troponin I, as well as examined cytokines compared to the healthy controls. Furthermore, ACE-2 mRNA and NRP-1 mRNA expression levels demonstrated a significant increase in both severe and moderate COVID-19 patient groups. In the severe group, serum creatinine and urea levels were positively correlated with IL-10, INF-γ, NRP-1, and ACE-2 expression levels. Moreover, LDH was positively correlated with all the examined cytokine, NRP-1, and ACE-2 expression levels. Conclusion: Deficits in renal and cardiac functions might be attributable to cytokine storm resulting from the higher expression of ACE-2 and NRP-1 in cases of COVID-19.

Gene Networks of Hyperglycemia, Diabetic Complications, and Human Proteins Targeted by SARS-CoV-2: What Is the Molecular Basis for Comorbidity?

People with diabetes are more likely to have severe COVID-19 compared to the general population. Moreover, diabetes and COVID-19 demonstrate a certain parallelism in the mechanisms and organ damage. In this work, we applied bioinformatics analysis of associative molecular networks to identify key molecules and pathophysiological processes that determine SARS-CoV-2-induced disorders in patients with diabetes. Using text-mining-based approaches and ANDSystem as a bioinformatics tool, we reconstructed and matched networks related to hyperglycemia, diabetic complications, insulin resistance, and beta cell dysfunction with networks of SARS-CoV-2-targeted proteins. The latter included SARS-CoV-2 entry receptors (ACE2 and DPP4), SARS-CoV-2 entry associated proteases (TMPRSS2, CTSB, and CTSL), and 332 human intracellular proteins interacting with SARS-CoV-2. A number of genes/proteins targeted by SARS-CoV-2 (ACE2, BRD2, COMT, CTSB, CTSL, DNMT1, DPP4, ERP44, F2RL1, GDF15, GPX1, HDAC2, HMOX1, HYOU1, IDE, LOX, NUTF2, PCNT, PLAT, RAB10, RHOA, SCARB1, and SELENOS) were found in the networks of vascular diabetic complications and insulin resistance. According to the Gene Ontology enrichment analysis, the defined molecules are involved in the response to hypoxia, reactive oxygen species metabolism, immune and inflammatory response, regulation of angiogenesis, platelet degranulation, and other processes. The results expand the understanding of the molecular basis of diabetes and COVID-19 comorbidity.

Sex-adjusted approach to baseline variables demonstrated some improved predictive capabilities for disease severity and survival in patients with Coronavirus Disease 19

INTRODUCTION

The study was focused on comparing crude and sex-adjusted hazard ratio calculated by the baseline variables which may have contributed to the severity of the disease course and fatal outcomes in Coronavirus Disease-19 (COVID-19) patients.

METHOD

The study enrolled 150 eligible adult patients with confirmed SARS-CoV-2 infection. There were 61 (40.7%) male patients, and 89 (59.3%) female patients. Baseline information of patients was collected from patient medical records and surveys that the patients had completed on admission to the hospital.

RESULTS

Considerable number of baseline variables stratified according to disease severity and outcomes showed different optimal cut-points (OCP) in men and women. Sex-adjusted baseline data categories such as age; BMI; systolic and diastolic blood pressure; peripheral RBC and platelet counts; haematocrit; percentage of neutrophils, lymphocytes, monocytes, and their ratio; percentage of eosinophils; titre of plasma IL-6, IL-8, IL-10, and IL-17; and CXCL10; and ratio of pro- and anti-inflammatory cytokines demonstrated significant impacts on the development of the severe stage and fatal outcomes by the mean hazard ratio in the Kaplan-Meier and Cox regression models.

CONCLUSION

This study confirmed some improved predictive capabilities of the sex-adjusted approach in the analysis of the baseline predictive variables for severity and outcome of the COVID-19.

Distinct Cytokine Profiles in Severe COVID-19 and Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is identified as a risk factor for developing severe COVID-19. While NAFLD is associated with chronic low-grade inflammation, mechanisms leading to immune system hyperactivation remain unclear. The aim of this prospective observational study is to analyze cytokine profiles in patients with severe COVID-19 and NAFLD. A total of 94 patients with severe COVID-19 were included. Upon admission, clinical and laboratory data were collected, a liver ultrasound was performed to determine the presence of steatosis, and subsequently, 51 were diagnosed with NAFLD according to the current guidelines. There were no differences in age, sex, comorbidities, and baseline disease severity between the groups. Serum cytokine concentrations were analyzed using a multiplex bead-based assay by flow cytometry. Upon admission, the NAFLD group had higher C-reactive protein, procalcitonin, alanine aminotransferase, lactate dehydrogenase, and fibrinogen. Interleukins-6, -8, and -10 and CXCL10 were significantly higher, while IFN-γ was lower in NAFLD patients. Patients with NAFLD who progressed to critical illness had higher concentrations of IL-6, -8, -10, and IFN-β, and IL-8 and IL-10 appear to be effective prognostic biomarkers associated with time to recovery. In conclusion, NAFLD is associated with distinct cytokine profiles in COVID-19, possibly associated with disease severity and adverse outcomes.

Extracellular ATP and Imbalance of CD4+ T Cell Compartment in Pediatric COVID-19

Severe COVID-19 in children is rare, but the reasons underlying are unclear. Profound alterations in T cell responses have been well characterized in the course of adult severe COVID-19, but little is known about the T cell function in children with COVID-19. Here, we made three major observations in a cohort of symptomatic children with acute COVID-19: 1) a reduced frequency of circulating FoxP3+ regulatory T cells, 2) the prevalence of a TH17 polarizing microenvironment characterized by high plasma levels of IL-6, IL-23, and IL17A, and an increased frequency of CD4+ T cells expressing ROR-γt, the master regulator of TH17 development, and 3) high plasma levels of ATP together with an increased expression of the P2X7 receptor. Moreover, that plasma levels of ATP displayed an inverse correlation with the frequency of regulatory T cells but a positive correlation with the frequency of CD4+ T cells positive for the expression of ROR-γt. Collectively, our data indicate an imbalance in CD4+ T cell profiles during pediatric COVID-19 that might favor the course of inflammatory processes. This finding also suggests a possible role for the extracellular ATP in the acquisition of an inflammatory signature by the T cell compartment offering a novel understanding of the involved mechanisms.

Identifying Immunological and Clinical Predictors of COVID-19 Severity and Sequelae by Mathematical Modeling

Since its emergence as a pandemic in March 2020, coronavirus disease (COVID-19) outcome has been explored via several predictive models, using specific clinical or biochemical parameters. In the current study, we developed an integrative non-linear predictive model of COVID-19 outcome, using clinical, biochemical, immunological, and radiological data of patients with different disease severities. Initially, the immunological signature of the disease was investigated through transcriptomics analysis of nasopharyngeal swab samples of patients with different COVID-19 severity versus control subjects (exploratory cohort, n=61), identifying significant differential expression of several cytokines. Accordingly, 24 cytokines were validated using a multiplex assay in the serum of COVID-19 patients and control subjects (validation cohort, n=77). Predictors of severity were Interleukin (IL)-10, Programmed Death-Ligand-1 (PDL-1), Tumor necrosis factors-α, absolute neutrophil count, C-reactive protein, lactate dehydrogenase, blood urea nitrogen, and ferritin; with high predictive efficacy (AUC=0.93 and 0.98 using ROC analysis of the predictive capacity of cytokines and biochemical markers, respectively). Increased IL-6 and granzyme B were found to predict liver injury in COVID-19 patients, whereas interferon-gamma (IFN-γ), IL-1 receptor-a (IL-1Ra) and PD-L1 were predictors of remarkable radiological findings. The model revealed consistent elevation of IL-15 and IL-10 in severe cases. Combining basic biochemical and radiological investigations with a limited number of curated cytokines will likely attain accurate predictive value in COVID-19. The model-derived cytokines highlight critical pathways in the pathophysiology of the COVID-19 with insight towards potential therapeutic targets. Our modeling methodology can be implemented using new datasets to identify key players and predict outcomes in new variants of COVID-19.

Cytokines from Bench to Bedside: A Retrospective Study Identifies a Definite Panel of Biomarkers to Early Assess the Risk of Negative Outcome in COVID-19 Patients

The main aim of this study was to identify the most relevant cytokines which, when assessed in the earliest stages from hospital admission, may help to select COVID-19 patients with worse prognosis. A retrospective observational study was conducted in 415 COVID-19 patients (272 males; mean age 68 ± 14 years) hospitalized between May 2020 and March 2021. Within the first 72 h from hospital admission, patients were tested for a large panel of biomarkers, including C-reactive protein (CRP), Mid-regional proadrenomedullin (MR-proADM), Interferon-γ, interleukin 6 (IL-6), IL-1β, IL-8, IL-10, soluble IL2-receptor-α (sIL2Rα), IP10 and TNFα. Extensive statistical analyses were performed (correlations, t-tests, ranking tests and tree modeling). The mortality rate was 65/415 (15.7%) and a negative outcome (death and/or orotracheal intubation) affected 98/415 (23.6%) of cases. Univariate tests showed the majority of biomarkers increased in severe patients, but ranking tests helped to select the best variables to put on decisional tree modeling which identified IL-6 as the first dichotomic marker with a cut-off of 114 pg/mL. Then, a good synergy was found between IL-10, MR-proADM, sIL2Rα, IP10 and CRP in increasing the predictive value in classifying patients at risk or not for a negative outcome. In conclusion, beside IL-6, a panel of other cytokines representing the degree of immunoparalysis and the anti-inflammatory response (IP10, sIL2Rα and IL-10) showed synergic role when combined to biomarkers of systemic inflammation and endothelial dysfunction (CRP, MR-proADM) and may also better explain disease pathogenesis and suggests targeted intervention.

The relationship between peripheral immune response and disease severity in SARS-CoV-2-infected subjects: A cross-sectional study

Coronavirus disease 2019 (COVID-19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and marked by an intense inflammatory response and immune dysregulation in the most severe cases. In order to better clarify the relationship between peripheral immune system changes and the severity of COVID-19, this study aimed to evaluate the frequencies and absolute numbers of peripheral subsets of neutrophils, monocytes, and dendritic cells (DCs), in addition to quantifying the levels of inflammatory mediators. One hundred fifty-seven COVID-19 patients were stratified into mild, moderate, severe, and critical disease categories. The cellular components and circulating cytokines were assessed by flow cytometry. Nitric oxide (NOx) and myeloperoxidase (MPO) levels were measured by colourimetric tests. COVID-19 patients presented neutrophilia, with signs of emergency myelopoiesis. Alterations in the monocytic component were observed in patients with moderate to critical illness, with an increase in classical monocytes and a reduction in nonclassical monocytes, in addition to a reduction in the expression of HLA-DR in all subtypes of monocytes, indicating immunosuppression. DCs, especially plasmacytoid DCs, also showed a large reduction in moderate to critical patients. COVID-19 patients showed an increase in MPO, interleukin (IL)-12, IL-6, IL-10, and IL-8, accompanied by a reduction in IL-17A and NOx. IL-10 levels ≥14 pg/ml were strongly related to the worst outcome, with a sensitivity of 78·3% and a specificity of 79·1%. The results of this study indicate the presence of systemic effects induced by COVID-19, which appear to be related to the pathophysiology of the disease, highlighting the potential of IL-10 as a possible prognostic biomarker for COVID-19.

Anti-inflammatory response of cardamom extract and prediction of therapeutic window in COVID-19 patients by assessing inflammatory markers using RT-PCR

INTRODUCTION

Molecular diagnostics using RT-PCR has now emerged as the new diagnostic method for clinicians with the dawn of SARS-CoV-2. In India, the popularity and awareness of RT-PCR and particularly the increased availability of testing machines across hospitals has now opened up possibilities of diagnostic tests with RT-PCR. In view of the cytokine storm which is the significant reason for morbidity and mortality of COVID-19 patients, we proposed to test the usefulness of a multiplex RT-PCR test kit that simultaneously measured inflammatory markers namely, IL-6, TNF- α and IL-10 (IFM) all in one tube. The study included a group of patients who were equally allotted to two treatment arms one of which received standard of care along with a food supplement capsule as a natural anti-inflammatory (RECOVEREEZ FORTE™), and the other group received standard of care that included oral Prednisolone tablets in tapered dosage. RECOVEREEZ FORTE™ consists of potent biomolecules from cardamom extract. A natural product with substantial anti-inflammatory action when consumed early at the onset of symptoms is hereby proven by comparing gene expression profile of inflammatory markers with routinely tested inflammatory parameters such as serum IL-6, CRP and LDH. In addition to predicting worse disease outcomes beforehand, RT-PCR assay tests provides an opportunity for identifying therapeutic window aiding in practicing effective treatment strategy for COVID-19. RT-PCR analysis of IFM together being used in a single multiplex kit is being first reported and such a test as a prognosticator for disease progression does seem promising and worthy of clinicians adopting novel testing modalities in clinical practice.

AIM OF THE STUDY

To study the anti-inflammatory response of RECOVEREEZ FORTE™ using RT-PCR based multiplex gene profiling of inflammatory markers in disease prognosis and show its predictability of worsening outcomes and its role in identifying therapeutic window for RECOVEREEZ FORTE™. To show the potentiality of RECOVEREEZ FORTE™ in reducing COVID-19 symptoms and SARS-CoV-2 RT-PCR Ct values of the treatment group.

MATERIALS AND METHODS

This was a short study of a 10-day period where the end point was the negativity of COVID-19 on RT-PCR test or the decline in cycle threshold (Ct) values of the test performed on day 10 when compared to day 0. During the course of the study, patients were given standard treatment and an oral dose of 500 mg of RECOVEREEZ FORTE™ thrice daily, or standard of care and oral Prednisolone in tapered dosage (control group). All essential interventions were included in the standard of care as decided by the attending physician. The RT-PCR results of inflammatory markers were compared to routinely tested parameters such as IL-6, CRP and LDH. Time to clinical improvement was in terms of SARS-CoV-2 RT-PCR test negativity or recovery of COVID-19 symptoms. We enrolled 64 patients, of which 32 were allocated to RECOVEREEZ FORTE ™ group and 32 to the control group.

RESULTS

The RT-PCR analysis of elevated IFM on day 0 corresponded to above normal protein levels of routinely tested parameters such as serum IL-6, CRP and LDH on day 5. Similarly, elevated IFM on day 5 corresponded to above normal protein levels on day 10. Such an association was equally prevalent in both the control group and RECOVEREEZ FORTE™ group, stipulating that RECOVEREEZ FORTE™ may be used as an alternative to steroids. The obtained results indicate that the RT-PCR assessment predicts worse outcomes 5 days earlier. But, the RT-PCR analysis of elevated IFM on day 0 did not correspond to the above normal protein levels of other parameters on day 10. Hence, indicating that the IFM RT-PCR test cannot predict worse outcomes 10 days earlier. Also, RECOVEREEZ FORTE™ when consumed for a period of 10 days normalized LDH values, compared to the control group. Moreover, IFM RT-PCR test identified a 5-day therapeutic window for RECOVEREEZ FORTE™ against inflammation experienced by patients. In addition to the above findings, the authors also observed that majority of the patients belonging to the treatment group showed recovery from symptoms such as fever, cough, sore throat and breathlessness compared to control group by day 5. 12 (37.5%) out of 32 patients and 6 (18.75%) out of 32 patients belonging to the treatment group and control group, respectively, became SARS-CoV-2 negative by day 5, indicating a probable anti-viral action of RECOVEREEZ FORTE™ against SARS-CoV-2.

CONCLUSION

The IFM RT-PCR test possess 5-day early prediction ability and lacks 10-day prediction ability. Treatment with RECOVEREEZ FORTE™ indicates good anti-inflammatory action which is equivalent to steroids. Intake of RECOVEREEZ FORTE ™ for a period of 5 days depicts persistent anti-inflammatory action, recovery of COVID-19 symptoms and a probable anti-viral action. Moreover, an effective normalization of LDH may be rendered by RECOVEREEZ FORTE™ when consumed for a period of 10 days.

Efficacy and Safety of Complementary Therapy With Jing Si Herbal Tea in Patients With Mild-To-Moderate COVID-19: A Prospective Cohort Study

Background

Since late 2019, there has been a global COVID-19 pandemic. To preserve medical capacity and decrease adverse health effects, preventing the progression of COVID-19 to severe status is essential. Jing-Si Herbal Tea (JSHT), a novel traditional Chinese medicine formula was developed to treat COVID-19. This study examined the clinical efficacy and safety of JSHT in patients with mild-to-moderate COVID-19.

Methods

In this prospective cohort study, we enrolled 260 patients with mild-to-moderate COVID-19. The enrolled patients were divided into the JSHT (n = 117) and control (n = 143) groups. Both groups received standard management. The JSHT group was treated with JSHT as a complementary therapy.

Results

Compared with standard management alone, JSHT combined with standard management more effectively improved the reverse transcription–polymerase chain reaction cycle threshold value, C-reactive protein level, and Brixia score in the adult patients with mild-to-moderate COVID-19, especially in the male and older patients (those aged ≥60 years). The results revealed that the patients treated with JSHT combined with standard management had 51, 70, and 100% lower risks of intubation, Medisave Care Unit admission, and mortality compared with those receiving standard management only.

Conclusions

JSHT combined with standard management more effectively reduced the SARS-CoV-2 viral load and systemic inflammation and alleviated lung infiltrates in the patients with mild-to-moderate COVID-19, especially in the male and older patients (those aged ≥60 years). JSHT combined with standard management may prevent critical status and mortality in patients with mild-to-moderate COVID-19. JSHT is a promising complementary therapy for patients with mild-to-moderate COVID-19.

Immune interventions in COVID-19: a matter of time?

As the COVID-19 pandemic is still ongoing, and considering the lack of efficacy of antiviral strategies to this date, and the reactive hyperinflammation leading to tissue lesions and pneumonia, effective treatments targeting the dysregulated immune response are more than ever required. Immunomodulatory and immunosuppressive drugs have been repurposed in severe COVID-19 with contrasting results. The heterogeneity in the timing of treatments administrations could be accountable for these discrepancies. Indeed, many studies included patients at different timepoints of infection, potentially hiding the beneficial effects of a time-adapted intervention. We aim to review the available data on the kinetics of the immune response in beta-coronaviruses infections, from animal models and longitudinal human studies, and propose a four-step model of severe COVID-19 timeline. Then, we discuss the results of the clinical trials of immune interventions with regards to the timing of administration, and finally suggest a time frame in order to delineate the best timepoint for each treatment.

Differential Co-Expression Network Analysis Reveals Key Hub-High Traffic Genes as Potential Therapeutic Targets for COVID-19 Pandemic

Background

The recent emergence of COVID-19, rapid worldwide spread, and incomplete knowledge of molecular mechanisms underlying SARS-CoV-2 infection have limited development of therapeutic strategies. Our objective was to systematically investigate molecular regulatory mechanisms of COVID-19, using a combination of high throughput RNA-sequencing-based transcriptomics and systems biology approaches.

Methods

RNA-Seq data from peripheral blood mononuclear cells (PBMCs) of healthy persons, mild and severe 17 COVID-19 patients were analyzed to generate a gene expression matrix. Weighted gene co-expression network analysis (WGCNA) was used to identify co-expression modules in healthy samples as a reference set. For differential co-expression network analysis, module preservation and module-trait relationships approaches were used to identify key modules. Then, protein-protein interaction (PPI) networks, based on co-expressed hub genes, were constructed to identify hub genes/TFs with the highest information transfer (hub-high traffic genes) within candidate modules.

Results

Based on differential co-expression network analysis, connectivity patterns and network density, 72% (15 of 21) of modules identified in healthy samples were altered by SARS-CoV-2 infection. Therefore, SARS-CoV-2 caused systemic perturbations in host biological gene networks. In functional enrichment analysis, among 15 non-preserved modules and two significant highly-correlated modules (identified by MTRs), 9 modules were directly related to the host immune response and COVID-19 immunopathogenesis. Intriguingly, systemic investigation of SARS-CoV-2 infection identified signaling pathways and key genes/proteins associated with COVID-19's main hallmarks, e.g., cytokine storm, respiratory distress syndrome (ARDS), acute lung injury (ALI), lymphopenia, coagulation disorders, thrombosis, and pregnancy complications, as well as comorbidities associated with COVID-19, e.g., asthma, diabetic complications, cardiovascular diseases (CVDs), liver disorders and acute kidney injury (AKI). Topological analysis with betweenness centrality (BC) identified 290 hub-high traffic genes, central in both co-expression and PPI networks. We also identified several transcriptional regulatory factors, including NFKB1, HIF1A, AHR, and TP53, with important immunoregulatory roles in SARS-CoV-2 infection. Moreover, several hub-high traffic genes, including IL6, IL1B, IL10, TNF, SOCS1, SOCS3, ICAM1, PTEN, RHOA, GDI2, SUMO1, CASP1, IRAK3, HSPA5, ADRB2, PRF1, GZMB, OASL, CCL5, HSP90AA1, HSPD1, IFNG, MAPK1, RAB5A, and TNFRSF1A had the highest rates of information transfer in 9 candidate modules and central roles in COVID-19 immunopathogenesis.

Conclusion

This study provides comprehensive information on molecular mechanisms of SARS-CoV-2-host interactions and identifies several hub-high traffic genes as promising therapeutic targets for the COVID-19 pandemic.

Hamster organotypic kidney culture model of early-stage SARS-CoV-2 infection highlights a two-step renal susceptibility

Kidney pathology is frequently reported in patients hospitalized with COVID-19, the pandemic disease caused by the Severe acute respiratory coronavirus 2 (SARS-CoV-2). However, due to a lack of suitable study models, the events occurring in the kidney during the earliest stages of infection remain unknown. We have developed hamster organotypic kidney cultures (OKCs) to study the early stages of direct renal infection. OKCs maintained key renal structures in their native three-dimensional arrangement. SARS-CoV-2 productively replicated in hamster OKCs, initially targeting endothelial cells and later disseminating into proximal tubules. We observed a delayed interferon response, markers of necroptosis and pyroptosis, and an early repression of pro-inflammatory cytokines transcription followed by a strong later upregulation. While it remains an open question whether an active replication of SARS-CoV-2 takes place in the kidneys of COVID-19 patients with AKI, our model provides new insights into the kinetics of SARS-CoV-2 kidney infection and can serve as a powerful tool for studying kidney infection by other pathogens and testing the renal toxicity of drugs.

IL-10 as a Th2 Cytokine: Differences Between Mice and Humans

The discovery of IL-10 more than 30 years ago marked the beginning of our understanding of how cytokines regulate immune responses, based on cross-regulation between Th1 and Th2 cytokines. Although multiple cell types were shown to produce IL-10, its identity as a Th2 cytokine remained strong because it was rigidly associated with Th2 clones in mice, whereas both Th1 and Th2 clones could secrete IL-10 in humans. However, as new Th1/Th2 cell functionalities emerged, anti-inflammatory action of IL-10 gained more attention than its inhibitory effect on Th1 cells, which may occur as an indirect consequence of suppression of APCs. This notion is also supported by the discovery of regulatory T cells, whose suppressor functions involve the mediation of IL-10, among other molecules. From this perspective, we discuss the functionalities of IL-10 by highlighting important differences between mice and humans with an emphasis on the Th1 and Th2 paradigm.

Interpreting 'anti-inflammatory' cytokine responses to exercise: focus on interleukin-10

Circulating concentrations of canonically pro- and anti-inflammatory cytokines are commonly measured when evaluating the anti-inflammatory effects of exercise. An important caveat to interpreting systemic cytokine concentrations as evidence for the anti-inflammatory effects of exercise is the observed dissociation between circulating cytokine concentrations and cytokine function at the tissue/cellular level. The dichotomization of cytokines as pro- or anti-inflammatory also overlooks the context dependence of cytokine function, which can vary depending on the physiological state being studied, the cytokine's cellular source/target, and magnitude of cytokine responses. We re-evaluate our current understanding of anti-inflammatory cytokine responses to exercise by highlighting nuances surrounding the interpretation of altered systemic cytokine concentrations as evidence for changes in inflammatory processes occurring at the tissue/cellular level. We highlight the lesser known pro-inflammatory and immunostimulatory actions of the prototypical anti-inflammatory cytokine, interleukin (IL)-10, including the potentiation of interferon gamma production during endotoxaemia, CD8⁺ T cell activation in tumour bearing rodents and cancer patients in vivo, and CD8⁺ T lymphocyte and natural killer cell activation in vitro. IL-10's more well-established anti-inflammatory actions can also be blunted following exercise training and under chronic inflammatory states such as type 2 diabetes (T2D) independently of circulating IL-10 concentrations. The resistance to IL-10's anti-inflammatory action in T2D coincides with blunted STAT3 phosphorylation and can be restored with small-molecule activators of IL-10 signalling, highlighting potential therapeutic avenues for restoring IL-10 action. We posit that inferences based on altered circulating cytokine concentrations alone can miss important functional changes in cytokine action occurring at the tissue/cellular level.