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1.
Dis Markers ; 2021: 6803510, 2021.
Article in English | MEDLINE | ID: covidwho-1443673

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most significant public health threat worldwide. Patients with severe COVID-19 usually have pneumonia concomitant with local inflammation and sometimes a cytokine storm. Specific components of the SARS-CoV-2 virus trigger lung inflammation, and recruitment of immune cells to the lungs exacerbates this process, although much remains unknown about the pathogenesis of COVID-19. Our study of lung type II pneumocyte cells (A549) demonstrated that ORF7, an open reading frame (ORF) in the genome of SARS-CoV-2, induced the production of CCL2, a chemokine that promotes the chemotaxis of monocytes, and decreased the expression of IL-8, a chemokine that recruits neutrophils. A549 cells also had an increased level of IL-6. The results of our chemotaxis Transwell assay suggested that ORF7 augmented monocyte infiltration and reduced the number of neutrophils. We conclude that the ORF7 of SARS-CoV-2 may have specific effects on the immunological changes in tissues after infection. These results suggest that the functions of other ORFs of SARS-CoV-2 should also be comprehensively examined.


Subject(s)
COVID-19/metabolism , Chemotaxis , Monocytes/pathology , Neutrophils/pathology , Open Reading Frames/physiology , Pneumonia/pathology , Viral Proteins/metabolism , A549 Cells , Chemokine CCL2/metabolism , Humans , In Vitro Techniques , Monocytes/immunology , Monocytes/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Pneumonia/immunology , Pneumonia/metabolism , SARS-CoV-2/metabolism , Viral Proteins/genetics
2.
Stem Cell Reports ; 16(9): 2274-2288, 2021 09 14.
Article in English | MEDLINE | ID: covidwho-1360129

ABSTRACT

Heart injury has been reported in up to 20% of COVID-19 patients, yet the cause of myocardial histopathology remains unknown. Here, using an established in vivo hamster model, we demonstrate that SARS-CoV-2 can be detected in cardiomyocytes of infected animals. Furthermore, we found damaged cardiomyocytes in hamsters and COVID-19 autopsy samples. To explore the mechanism, we show that both human pluripotent stem cell-derived cardiomyocytes (hPSC-derived CMs) and adult cardiomyocytes (CMs) can be productively infected by SARS-CoV-2, leading to secretion of the monocyte chemoattractant cytokine CCL2 and subsequent monocyte recruitment. Increased CCL2 expression and monocyte infiltration was also observed in the hearts of infected hamsters. Although infected CMs suffer damage, we find that the presence of macrophages significantly reduces SARS-CoV-2-infected CMs. Overall, our study provides direct evidence that SARS-CoV-2 infects CMs in vivo and suggests a mechanism of immune cell infiltration and histopathology in heart tissues of COVID-19 patients.


Subject(s)
COVID-19/pathology , Chemokine CCL2/metabolism , Heart Injuries/virology , Monocytes/immunology , Myocytes, Cardiac/metabolism , Animals , Cell Communication/physiology , Cell Line , Chlorocebus aethiops , Cricetinae , Disease Models, Animal , Humans , Macrophages/immunology , Male , Myocytes, Cardiac/virology , Pluripotent Stem Cells/cytology , Vero Cells
3.
Front Immunol ; 12: 707287, 2021.
Article in English | MEDLINE | ID: covidwho-1359191

ABSTRACT

Background: The outbreak of Coronavirus disease 2019 (COVID-19) has become an international public health crisis, and the number of cases with dengue co-infection has raised concerns. Unfortunately, treatment options are currently limited or even unavailable. Thus, the aim of our study was to explore the underlying mechanisms and identify potential therapeutic targets for co-infection. Methods: To further understand the mechanisms underlying co-infection, we used a series of bioinformatics analyses to build host factor interaction networks and elucidate biological process and molecular function categories, pathway activity, tissue-specific enrichment, and potential therapeutic agents. Results: We explored the pathologic mechanisms of COVID-19 and dengue co-infection, including predisposing genes, significant pathways, biological functions, and possible drugs for intervention. In total, 460 shared host factors were collected; among them, CCL4 and AhR targets were important. To further analyze biological functions, we created a protein-protein interaction (PPI) network and performed Molecular Complex Detection (MCODE) analysis. In addition, common signaling pathways were acquired, and the toll-like receptor and NOD-like receptor signaling pathways exerted a significant effect on the interaction. Upregulated genes were identified based on the activity score of dysregulated genes, such as IL-1, Hippo, and TNF-α. We also conducted tissue-specific enrichment analysis and found ICAM-1 and CCL2 to be highly expressed in the lung. Finally, candidate drugs were screened, including resveratrol, genistein, and dexamethasone. Conclusions: This study probes host factor interaction networks for COVID-19 and dengue and provides potential drugs for clinical practice. Although the findings need to be verified, they contribute to the treatment of co-infection and the management of respiratory disease.


Subject(s)
COVID-19/drug therapy , COVID-19/pathology , Computational Biology/methods , Dengue/drug therapy , Dengue/pathology , Protein Interaction Maps/physiology , Antiviral Agents/therapeutic use , Chemokine CCL2/metabolism , Coinfection , Dengue Virus/drug effects , Dexamethasone/therapeutic use , Gene Expression Regulation/genetics , Genistein/therapeutic use , Humans , Intercellular Adhesion Molecule-1/metabolism , Lung/metabolism , Resveratrol/therapeutic use , SARS-CoV-2/drug effects , Signal Transduction
4.
J Biol Chem ; 297(2): 100925, 2021 08.
Article in English | MEDLINE | ID: covidwho-1336599

ABSTRACT

Apart from prevention using vaccinations, the management options for COVID-19 remain limited. In retrospective cohort studies, use of famotidine, a specific oral H2 receptor antagonist (antihistamine), has been associated with reduced risk of intubation and death in patients hospitalized with COVID-19. In a case series, nonhospitalized patients with COVID-19 experienced rapid symptom resolution after taking famotidine, but the molecular basis of these observations remains elusive. Here we show using biochemical, cellular, and functional assays that famotidine has no effect on viral replication or viral protease activity. However, famotidine can affect histamine-induced signaling processes in infected Caco2 cells. Specifically, famotidine treatment inhibits histamine-induced expression of Toll-like receptor 3 (TLR3) in SARS-CoV-2 infected cells and can reduce TLR3-dependent signaling processes that culminate in activation of IRF3 and the NF-κB pathway, subsequently controlling antiviral and inflammatory responses. SARS-CoV-2-infected cells treated with famotidine demonstrate reduced expression levels of the inflammatory mediators CCL-2 and IL6, drivers of the cytokine release syndrome that precipitates poor outcome for patients with COVID-19. Given that pharmacokinetic studies indicate that famotidine can reach concentrations in blood that suffice to antagonize histamine H2 receptors expressed in mast cells, neutrophils, and eosinophils, these observations explain how famotidine may contribute to the reduced histamine-induced inflammation and cytokine release, thereby improving the outcome for patients with COVID-19.


Subject(s)
Famotidine/pharmacology , Histamine Antagonists/pharmacology , SARS-CoV-2/drug effects , Toll-Like Receptor 3/metabolism , A549 Cells , Binding Sites , Caco-2 Cells , Chemokine CCL2/metabolism , Coronavirus 3C Proteases/metabolism , HeLa Cells , Humans , Interferon Regulatory Factor-3/metabolism , Interleukin-6/metabolism , Molecular Docking Simulation , NF-kappa B/metabolism , Protein Binding , SARS-CoV-2/physiology , Signal Transduction , Toll-Like Receptor 3/chemistry , Virus Replication
5.
PLoS One ; 16(6): e0252758, 2021.
Article in English | MEDLINE | ID: covidwho-1261297

ABSTRACT

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) has been implicated in the pathogenesis of experimental kidney disease. ACE2 is on the X chromosome, and in mice, deletion of ACE2 leads to the development of focal segmental glomerulosclerosis (FSGS). The relationship between sex and renal ACE2 expression in humans with kidney disease is a gap in current knowledge. METHODS: We studied renal tubulointerstitial microarray data and clinical variables from subjects with FSGS enrolled in the Nephrotic Syndrome Study Network (NEPTUNE) study. We compared relationships between ACE2 expression and age, estimated glomerular filtration rate (eGFR), urinary albumin to creatinine ratio (UACR), interstitial fibrosis, tubular atrophy, and genes implicated in inflammation and fibrosis in male and female subjects. RESULTS: ACE2 mRNA expression was lower in the tubulointerstitium of males compared to females (P = 0.0026). Multiple linear regression analysis showed that ACE2 expression was related to sex and eGFR but not to age or treatment with renin angiotensin system blockade. ACE2 expression is also related to interstitial fibrosis, and tubular atrophy, in males but not in females. Genes involved in inflammation (CCL2 and TNF) correlated with ACE2 expression in males (TNF: r = -0.65, P < 0.0001; CCL2: r = -0.60, P < 0.0001) but not in females. TGFB1, a gene implicated in fibrosis correlated with ACE2 in both sexes. CONCLUSIONS: Sex is an important determinant of ACE2 expression in the tubulointerstitium of the kidney in FSGS. Sex also influences the relationships between ACE2, kidney fibrosis, and expression of genes involved in kidney inflammation.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Glomerulosclerosis, Focal Segmental/metabolism , Adolescent , Adult , Angiotensin-Converting Enzyme 2/genetics , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Child , Female , Glomerulosclerosis, Focal Segmental/genetics , Glomerulosclerosis, Focal Segmental/pathology , Humans , Kidney/metabolism , Male , Middle Aged , Sex Factors , Transforming Growth Factor beta1/genetics , Transforming Growth Factor beta1/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
6.
J Am Coll Nutr ; 40(4): 327-332, 2021.
Article in English | MEDLINE | ID: covidwho-1087590

ABSTRACT

Objective: Vitamin D deficiency is common in the general population and diabetic patients, and supplementation with vitamin D is widely used to help lower oxidative stress and inflammation. The cytokine storm in SARS-CoV2 infection has been linked with both diabetes and Vitamin D deficiency. This study examined the hypothesis that supplementation with vitamin D, in combination with l-cysteine (LC), is better at reducing oxidative stress and thereby, more effective, at inhibiting the secretion of the pro-inflammatory cytokines, Interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in U937 monocytes exposed to high glucose concentrations. Methods: U937 monocytes were pretreated with 1,25 (OH)2 vitamin D (VD, 10 nM) or LC (250 µM) or VD + LC for 24 h and then exposed to control or high glucose (HG, 25 mM) for another 24 h. Results: There were significantly greater reactive oxygen species (ROS) levels in monocytes treated with HG than those in controls. Combined supplementation with VD and LC showed a more significant reduction in ROS (46%) in comparison with treatment with LC (19%) or VD (26%) alone in monocytes exposed to HG. Similarly, VD supplementation, together with LC, caused a more significant inhibition in the secretion of IL-8 (36% versus 16%) and MCP-1 (46% versus 26%) in comparison with that of VD (10 nM) alone in high-glucose treated monocytes. Conclusions: These results suggest that combined supplementation with vitamin D and LC has the potential to be more effective than either VD or LC alone in lowering the risk of oxidative stress and inflammation associated with type 2 diabetes or COVID-19 infection. Further, this combined vitamin D with LC/N-acetylcysteine may be a potent alternative therapy for SARS-CoV2 infected subjects. This approach can prevent cellular damage due to cytokine storm in comorbid systemic inflammatory conditions, such as diabetes, obesity, and hypertension.


Subject(s)
COVID-19/drug therapy , Cysteine/administration & dosage , Oxidative Stress/drug effects , SARS-CoV-2/immunology , Vitamin D/administration & dosage , COVID-19/immunology , Chemokine CCL2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Dietary Supplements , Drug Therapy, Combination , Glucose/administration & dosage , Humans , Interleukin-8/metabolism , Monocytes/immunology , Monocytes/virology , U937 Cells , Vitamin D Deficiency/drug therapy , Vitamin D Deficiency/immunology , Vitamin D Deficiency/virology
7.
EMBO Mol Med ; 12(10): e13038, 2020 10 07.
Article in English | MEDLINE | ID: covidwho-722035

ABSTRACT

Early in the COVID-19 pandemic, type 2 diabetes (T2D) was marked as a risk factor for severe disease and mortality. Inflammation is central to the aetiology of both conditions where variations in immune responses can mitigate or aggravate disease course. Identifying at-risk groups based on immunoinflammatory signatures is valuable in directing personalised care and developing potential targets for precision therapy. This observational study characterised immunophenotypic variation associated with COVID-19 severity in T2D. Broad-spectrum immunophenotyping quantified 15 leucocyte populations in peripheral circulation from a cohort of 45 hospitalised COVID-19 patients with and without T2D. Lymphocytopenia and specific loss of cytotoxic CD8+ lymphocytes were associated with severe COVID-19 and requirement for intensive care in both non-diabetic and T2D patients. A morphological anomaly of increased monocyte size and monocytopenia restricted to classical CD14Hi CD16- monocytes was specifically associated with severe COVID-19 in patients with T2D requiring intensive care. Increased expression of inflammatory markers reminiscent of the type 1 interferon pathway (IL6, IL8, CCL2, INFB1) underlaid the immunophenotype associated with T2D. These immunophenotypic and hyperinflammatory changes may contribute to increased voracity of COVID-19 in T2D. These findings allow precise identification of T2D patients with severe COVID-19 as well as provide evidence that the type 1 interferon pathway may be an actionable therapeutic target for future studies.


Subject(s)
COVID-19/pathology , Diabetes Mellitus, Type 2/pathology , Monocytes/physiology , Aged , COVID-19/complications , COVID-19/virology , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Diabetes Mellitus, Type 2/complications , Female , Humans , Immunophenotyping , Inflammation/etiology , Interleukin-6/genetics , Interleukin-6/metabolism , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/metabolism , Lipopolysaccharide Receptors/metabolism , Lymphopenia/diagnosis , Male , Middle Aged , Monocytes/cytology , Monocytes/pathology , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index
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