Extracellular Vesicles of COVID-19 Patients Reflect Inflammation, Thrombogenicity, and Disease Severity

Venous thromboembolism and severe COVID-19: a Mendelian randomization trial and transcriptomic analysis

Introduction

Venous thromboembolism (VTE) is known to be intricately linked to severe COVID-19 (sCOVID-19) occurrence. Herein, we employed univariable Mendelian randomization (MR) and transcriptome analysis to predict the causal association and associated signaling networks between VTE and sCOVID-19.

Methods

Potential VTE and sCOVID-19 association was assessed using MR-Egger, weighted median, simple mode, weighted mode, and inverse variance weighted (IVW) regression. We conducted independent univariable analyses involving VTE and sCOVID-19. Using heterogeneity, pleiotropy, and the Leave-One-Out examinations, we performed sensitivity analyses. Thereafter, we performed transcriptome analysis of the GSE164805 dataset to identify differentially expressed genes (DEGs) linked to single nucleotide polymorphisms (SNPs). Lastly, we conducted immune analyses.

Results

Based on our univariable analysis, VTE was a strong indicator of sCOVID-19 development, and it was intricately linked to sCOVID-19. We further conducted sensitivity analysis to demonstrate the reliability of our results. Using differential analysis, we identified 15 major genes, namely, ACSS2, CEP250, CYP4V2, DDB2, EIF6, GBGT1, GSS, MADD, MAPK8IP1, MMP24, YBPC3, NT5DC3, PROCR, SURF6, and YIPF2, which were strongly connected to suppressive adaptive immune as well as augmented inflammatory cells. In addition, we uncovered strong associations with most differential immunologic gene sets, such as, the Major Histocompatibility Complex (MHC), immunoactivators, and immunosuppressors.

Conclusion

Herein, we demonstrated we strong association between VTE and enhanced sCOVID-19 risk. We also identified 15 DEGs which potentially contribute to the shared immunologic pathogenesis between VTE and sCOVID-19.

Integrated analysis of RNA-seq datasets reveals novel targets and regulators of COVID-19 severity

During the COVID-19 pandemic, RNA-seq datasets were produced to investigate the virus-host relationship. However, much of these data remains underexplored. To improve the search for molecular targets and biomarkers, we performed an integrated analysis of multiple RNA-seq datasets, expanding the cohort and including patients from different countries, encompassing severe and mild COVID-19 patients. Our analysis revealed that severe COVID-19 patients exhibit overexpression of genes coding for proteins of extracellular exosomes, endomembrane system, and neutrophil granules (e.g., S100A9, LY96, and RAB1B), which may play an essential role in the cellular response to infection. Concurrently, these patients exhibit down-regulation of genes encoding components of the T cell receptor complex and nucleolus, including TP53, IL2RB, and NCL Finally, SPI1 may emerge as a central transcriptional factor associated with the up-regulated genes, whereas TP53, MYC, and MAX were associated with the down-regulated genes during COVID-19. This study identified targets and transcriptional factors, lighting on the molecular pathophysiology of syndrome coronavirus 2 infection.

Intrinsic factors behind long-COVID: II. SARS-CoV-2, extracellular vesicles, and neurological disorders

With the decline in the number of new Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections, the World Health Organization announced the end of the SARS-CoV-2 pandemic. However, the repercussions of this viral pandemic may remain with us for a longer period of time, as it has remodeled the lives of humankind in many ways, including social and economic. Of course, its most important repercussions remain on the human health level. Long-coronavirus disease (COVID) or post-COVID is a state for which we do not have a concrete definition, a specific international classification of diseases Code, clear diagnostic tools, or well-known effective cures as of yet. In this second article from the Intrinsic Factors behind long-COVID Series, we try to link long-COVID symptoms with their causes, starting from the nervous system. Extracellular vesicles (ECVs) play very complex and ramified roles in the bodies of both healthy and not-healthy individuals. ECVs may facilitate the entry of many bioactive molecules and pathogens into the tissues and cells of the nervous system across the blood-brain barrier. Based on the size, quantity, and quality of their cargo, ECVs are directly proportional to the pathological condition and its severity through intertwined mechanisms that evoke inflammatory immune responses typically accompanied by pathological symptoms over variable time periods according to the type of these symptoms.

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19. Here, we review cfDNA in general, how it has been identified, where it can derive from, its molecular features, and mechanisms of release and clearance. General suitability of cfDNA for diagnostic questions, possible shortcomings and future directions are discussed, with a special focus on coronavirus infection.

Characterization of extracellular vesicles in COVID-19 infection during pregnancy

Introduction: SARS-CoV-2 infection may cause a severe inflammatory response, inflicting severe morbidity and mortality. This risk is modestly increased in pregnant patients. Despite the hypercoagulability and immunosuppression associated with pregnancy, most pregnant women experience a mild COVID-19 infection. Maternal extracellular vesicles (EVs) may interact with endothelial and immune components to facilitate a favorable disease course. This pilot study aimed to explore the characteristics of EVs released during COVID-19 infection occurring during the third trimester of pregnancy. Methods: In this prospective study, blood samples were obtained from 16 healthy non-pregnant (NP), 18 healthy-pregnant (HP), and 22 COVID-19 positive pregnant subjects (CoV-P). Disease course and pregnancy outcomes were assessed and EVs were characterized. Of note, limited volumes of sample acquired from the subjects made it necessary to use smaller and different subsets of samples for each analysis. Results: The majority (91%) of the COVID-19-pregnant subjects (18 mild and 2 moderate disease) experienced good pregnancy-related outcomes. EV concentrations were higher in healthy-pregnant subjects compared to non-pregnant subjects (p = 0.0041) and lower in COVID-19-pregnant subjects compared to healthy-pregnant subjects (p = 0.0150). CD63 exosome marker expression was higher in EVs of healthy-pregnant subjects and COVID-19-pregnant subjects compared to EVs of non-pregnant subjects (p = 0.0149, p = 0.0028, respectively). Similar levels of SARS-CoV-2 entry proteins (ACE-2 and TMPRSS2) were found in all three groups. Cytokine content increased in healthy-pregnant subject-EVs compared to non-pregnant EVs, while IL-2 and IL-6 levels were decreased in COVID-19-pregnant subject-EVs compared to healthy-pregnant subject-EVs (p = 0.043, p = 0.0390, respectively). CD8+, cytotoxic T-cell marker, was lower in non-pregnant EVs compared to healthy-pregnant subject-EVs and to COVID-19-pregnant subjects (p = 0.0108, p < 0.0001, respectively). COVID-19- pregnant subject-EVs demonstrated higher levels of platelet activation marker (CD62P) than non-pregnant (p = 0.0327) and healthy-pregnant subjects (p = 0.0365). Endothelial marker EV-CD144+ was lower in healthy-pregnant subjects versus non-pregnant subjects (p = 0.0093), but similar in COVID-19-pregnant and non-pregnant subjects. Other EVs' coagulation markers/activity, D-Dimer and fibrinogen levels were similar in healthy-pregnant subjects and COVID-19 positive pregnant subjects. Conclusion: COVID-19 positive pregnant subjects' EVs demonstrated an attenuated inflammatory response, with no additional activation of the coagulation system.