Circulating markers of extracellular matrix remodelling in severe COVID-19 patients

Background Abnormal remodelling of the extracellular matrix (ECM) has generally been linked to pulmonary inflammation and fibrosis and may also play a role in the pathogenesis of severe COVID-19. To further elucidate the role of ECM remodelling and excessive fibrogenesis in severe COVID-19, we examined circulating levels of mediators involved in various aspects of these processes in COVID-19 patients. Methods Serial blood samples were obtained from two cohorts of hospitalised COVID-19 patients (n = 414). Circulating levels of ECM remodelling mediators were quantified by enzyme immunoassays in samples collected during hospitalisation and at 3-month follow-up. Samples were related to disease severity (respiratory failure and/or treatment at the intensive care unit), 60-day total mortality and pulmonary pathology after 3-months. We also evaluated the direct effect of inactivated SARS-CoV-2 on the release of the different ECM mediators in relevant cell lines. Results Several of the measured markers were associated with adverse outcomes, notably osteopontin (OPN), S100 calcium-binding protein A12 and YKL-40 were associated with disease severity and mortality. High levels of ECM mediators during hospitalisation were associated with computed tomography thorax pathology after 3-months. Some markers (i.e. growth differential factor 15, galectin 3 and matrix metalloproteinase 9) were released from various relevant cell lines (i.e. macrophages and lung cell lines) in vitro after exposure to inactivated SARS-CoV-2 suggesting a direct link between these mediators and the causal agent of COVID-19. Conclusion Our findings highlight changes to ECM remodelling and particularly a possible role of OPN, S100A12 and YKL-40 in the pathogenesis of severe COVID-19

Breakthrough infections with the omicron and delta variants of SARS-CoV-2 result in similar re-activation of vaccine-induced immunity

Background: Results showing that sera from double vaccinated individuals have minimal neutralizing activity against Omicron have been interpreted as indicating the need for a third vaccine dose for protection. However, there is little information about early immune responses to Omicron infection in double vaccinated individuals. Methods: We measured inflammatory mediators, antibodies to the SARS-CoV-2 spike and nucleocapsid proteins, and spike peptide-induced release of interferon gamma in whole blood in 51 double-vaccinated individuals infected with Omicron, in 14 infected with Delta, and in 18 healthy controls. The median time points for the first and second samples were 7 and 14 days after symptom onset, respectively. Findings: Infection with Omicron or Delta led to a rapid and similar increase in antibodies to the receptor-binding domain (RBD) of Omicron protein and spike peptide-induced interferon gamma in whole blood. Both the Omicron- and the Delta-infected patients had a mild and transient increase in inflammatory parameters. <p<Interpretation: The results suggest that two vaccine doses are sufficient to mount a rapid and potent immune response upon infection in healthy individuals of with the Omicron variant

Age sensitivity and effects in A/J APC Min/+ mice (Mus musculus) after exposure to Azoxymethane, a potent carcinogen.

Colon cancer (CRC) is one of the most common cancer types in Norway and the world. Coupled with a high mortality rate, the need for studies on CRC is of great importance. However, to study CRC, the need for suitable and robust animal models arises. The A/J Min/+ model has previously been established as an exemplary model for the studies on hereditary and spontaneous CRC. However, as the A/J Min/+ model displayed increased sensitivity to chemical carcinogens compared to the conventional Min/+ model, a need for characterisation of the age-dependent sensitivity to chemical carcinogens such as the procarcinogen AOM was identified. Due to the novelty of the model, no previous studies have charted the underlying mechanistic pathways which relate to the observed increased sensitivity in the A/J Min/+ model. Mice were injected once with AOM (8 mg/kg), at different ages (neonatal to juvenile) to characterise age-dependent sensitivity and terminated at 13 weeks of age. Screening of selected CYP enzymes involved in the metabolism of AOM was performed with in vitro metabolism of hepatic S9 fraction on mice terminated 24h after AOM exposure. Additionally, hepatic and colonic protein profiles were mapped with a proteomics approach to explore possible pathway modulations associated with CRC. Our results show that exposure to AOM in neonatal mice (7 days old) had no significant effect on the number of intestinal lesions. However, two- and four-week-old mice displayed higher sensitivity than neonatal mice and control. Additionally, our results confirm the involvement of Cyp2e1 in the metabolism of AOM in the A/J Min/+ model. The proteomics approach revealed modulations of CRC related pathways, apoptosis and cytoskeleton alterations. This thesis has provided more in-depth insight into the age-dependent sensitivity to chemical carcinogens in the A/J Min/+ model. The analysis of enzymatic activity and proteomic changes undertaken here has expanded our knowledge on how mechanistic pathways may stimulate the increased sensitivity in the A/J Min/+ model. Nevertheless, further research is needed to accurately characterise the age-dependent sensitivity to AOM in the A/J Min/+ model

Markers of cellular senescence is associated with persistent pulmonary pathology after COVID-19 infection

Background: The lungs are the organ most likely to sustain serious injury from coronavirus disease 2019 (COVID-19). However, the mechanisms for long-term complications are not clear. Patients with severe COVID-19 have shorter telomere lengths and higher levels of cellular senescence, and we hypothesized that circulating levels of the telomere-associated senescence markers chitotriosidase, b-galactosidase, cathelicidin antimicrobial peptide and stathmin 1 (STMN1) were elevated in hospitalized COVID-19 patients compared to controls and could be associated with pulmonary sequelae following hospitalization. Methods: Ninety-seven hospitalized patients with COVID-19 who underwent assessment for pulmonary sequelae at threemonth follow-up were included in the study. b-Galactosidase and chitotriosidase were analysed by fluorescence; stathmin 1 and cathelicidin antimicrobial peptide were analysed by enzyme immuno-assay in plasma samples from the acute phase and after three-months. In addition, the classical senescence markers cyclin-dependent kinase inhibitor 1A and 2A were analysed by enzyme immuno-assay in peripheral blood mononuclear cell lysate after three months. Results: We found elevated plasma levels of the senescence markers chitotriosidase and stathmin 1 in patients three months after hospitalization with COVID-19, and these markers in addition to protein levels of cyclin-dependent kinase inhibitor 2A in cell lysate, were associated with pulmonary pathology. The elevated levels of these markers seem to reflect both age-dependent (chitotriosidase) and age-independent (stathmin 1, cyclin-dependent kinase inhibitor 2A) processes. Conclusions: We suggest that accelerated ageing or senescence could be important for long-term pulmonary complications of COVID-19, and our findings may be relevant for future research exploring the pathophysiology and management of these patients

DNA Repair Mechanisms are Activated in Circulating Lymphocytes of Hospitalized Covid-19 Patients

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High circulating levels of the homeostatic chemokines CCL19 and CCL21 predict mortality and disease severity in Covid-19

Background Immune dysregulation is a major factor in the development of severe coronavirus disease 2019 (COVID-19). The homeostatic chemokines CCL19 and CCL21 have been implicated as mediators of tissue inflammation, but data on their regulation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is limited. We thus investigated the levels of these chemokines in COVID-19 patients. Methods Serial blood samples were obtained from patients hospitalized with COVID-19 (n = 414). Circulating CCL19 and CCL21 levels during hospitalization and 3-month follow-up were analyzed. In vitro assays and analysis of RNAseq data from public repositories were performed to further explore possible regulatory mechanisms. Results A consistent increase in circulating levels of CCL19 and CCL21 was observed, with high levels correlating with disease severity measures, including respiratory failure, need for intensive care, and 60-day all-cause mortality. High levels of CCL21 at admission were associated with persisting impairment of pulmonary function at the 3-month follow-up. Conclusions Our findings highlight CCL19 and CCL21 as markers of immune dysregulation in COVID-19. This may reflect aberrant regulation triggered by tissue inflammation, as observed in other chronic inflammatory and autoimmune conditions. Determination of the source and regulation of these chemokines and their effects on lung tissue is warranted to further clarify their role in COVID-19

High circulating levels of the homeostatic chemokines CCL19 and CCL21 predict mortality and disease severity in Covid-19

Abstract Background Immune dysregulation is a major factor in the development of severe coronavirus disease 2019 (COVID-19). The homeostatic chemokines CCL19 and CCL21 have been implicated as mediators of tissue inflammation, but data on their regulation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is limited. We thus investigated the levels of these chemokines in COVID-19 patients. Methods Serial blood samples were obtained from patients hospitalized with COVID-19 (n = 414). Circulating CCL19 and CCL21 levels during hospitalization and 3-month follow-up were analyzed. In vitro assays and analysis of RNAseq data from public repositories were performed to further explore possible regulatory mechanisms. Results A consistent increase in circulating levels of CCL19 and CCL21 was observed, with high levels correlating with disease severity measures, including respiratory failure, need for intensive care, and 60-day all-cause mortality. High levels of CCL21 at admission were associated with persisting impairment of pulmonary function at the 3-month follow-up. Conclusions Our findings highlight CCL19 and CCL21 as markers of immune dysregulation in COVID-19. This may reflect aberrant regulation triggered by tissue inflammation, as observed in other chronic inflammatory and autoimmune conditions. Determination of the source and regulation of these chemokines and their effects on lung tissue is warranted to further clarify their role in COVID-19. Clinical Trials Registration NCT04321616 and NCT04381819

Persistent T-cell exhaustion in relation to prolonged pulmonary pathology and death after severe COVID-19: Results from two Norwegian cohort studies

Background: T-cell activation is associated with an adverse outcome in COVID-19, but whether T-cell activation and exhaustion relate to persistent respiratory dysfunction and death is unknown. Objectives: To investigate whether T-cell activation and exhaustion persist and are associated with prolonged respiratory dysfunction and death after hospitalization for COVID-19. Methods: Plasma and serum from two Norwegian cohorts of hospitalized patients with COVID-19 (n = 414) were analyzed for soluble (s) markers of T-cell activation (sCD25) and exhaustion (sTim-3) during hospitalization and follow-up. Results: Both markers were strongly associated with acute respiratory failure, but only sTim-3 was independently associated with 60-day mortality. Levels of sTim-3 remained elevated 3 and 12 months after hospitalization and were associated with pulmonary radiological pathology after 3 months. Conclusion: Our findings suggest prolonged T-cell exhaustion is an important immunological sequela, potentially related to long-term outcomes after severe COVID-19

Persistent T-cell exhaustion in relation to prolonged pulmonary pathology and death after severe COVID-19: Results from two Norwegian cohort studies

Background - T-cell activation is associated with an adverse outcome in COVID-19, but whether T-cell activation and exhaustion relate to persistent respiratory dysfunction and death is unknown. Objectives - To investigate whether T-cell activation and exhaustion persist and are associated with prolonged respiratory dysfunction and death after hospitalization for COVID-19. Methods - Plasma and serum from two Norwegian cohorts of hospitalized patients with COVID-19 (n = 414) were analyzed for soluble (s) markers of T-cell activation (sCD25) and exhaustion (sTim-3) during hospitalization and follow-up. Results - Both markers were strongly associated with acute respiratory failure, but only sTim-3 was independently associated with 60-day mortality. Levels of sTim-3 remained elevated 3 and 12 months after hospitalization and were associated with pulmonary radiological pathology after 3 months. Conclusion - Our findings suggest prolonged T-cell exhaustion is an important immunological sequela, potentially related to long-term outcomes after severe COVID-19