Project description:Fatal COVID-19 is often complicated by hypoxemic respiratory failure and acute respiratory distress syndrome (ARDS). Mechanisms governing lung injury and repair in ARDS remain poorly understood because there are no biomarker-targeted therapeutics for patients with ARDS. We hypothesized that plasma proteomics may uncover unique biomarkers that correlate with disease severity in COVID-19 ARDS. We analyzed the circulating plasma proteome from 32 patients with ARDS and COVID-19 using an aptamer-based platform, which measures 7289 proteins, and correlated protein measurements with sequential organ failure assessment (SOFA) scores at 2 time points (Days 1 and 7 following ICU admission). We compared differential protein abundance and SOFA scores at each individual time point and identified 119 proteins at Day 1 and 46 proteins at Day 7 that correlated with patient SOFA scores. We modeled the relationship between dynamic protein abundance and changes in SOFA score between Days 1 and 7 and identified 39 proteins that significantly correlated with changes in SOFA score. Using Ingenuity Pathway Analysis, we identified increased ephrin signaling and acute phase response signaling correlated with increased SOFA scores over time, while pathways related to pulmonary fibrosis signaling and wound healing had an inverse relationship with SOFA scores between Days 1 and 7. These findings suggest that persistent inflammation may drive worsened disease severity, while repair processes correlate with improvements in organ dysfunction over time. This approach is generalizable to more diverse ARDS cohorts for identification of protein biomarkers and disease mechanisms as we strive towards targeted therapies in ARDS.
Project description:SARS-CoV-2 is a novel coronavirus that causes acute respiratory distress syndrome (ARDS), death and long-term sequelae. Innate immune cells are critical for host defense but are also the primary drivers of ARDS. The relationships between innate cellular responses in ARDS resulting from COVID-19 compared to other causes of ARDS, such as bacterial sepsis is unclear. Moreover, the beneficial effects of dexamethasone therapy during severe COVID-19 remain speculative, but understanding the mechanistic effects could improve evidence-based therapeutic interventions. To interrogate these relationships, we developed an scRNAseq atlas that is freely accessible (biernaskielab.ca/COVID_neutrophil). We discovered that compared to bacterial ARDS, COVID-19 was associated with distinct neutrophil polarization characterized by either interferon (IFN) or prostaglandin (PG) active states. Neutrophils from bacterial ARDS had higher expression of antibacterial molecules such as PLAC8 and CD83. Dexamethasone therapy in COVID patients rapidly altered the IFNactive state, downregulated interferon responsive genes, and activated IL1R2+ve neutrophils. Dexamethasone also induced the emergence of immature neutrophils expressing immunosuppressive molecules ARG1 and ANXA1, which were not present in healthy controls. Moreover, dexamethasone remodeled global cellular interactions by changing neutrophils from information receivers into information providers. Importantly, male patients had higher proportions of IFNactive neutrophils and a greater degree of steroid-induced immature neutrophil expansion. Indeed, the highest proportion of IFNactive neutrophils was associated with mortality. These results define neutrophil states unique to COVID-19 when contextualized to other life-threatening infections, thereby enhancing the relevance of our findings at the bedside. Furthermore, the molecular benefits of dexamethasone therapy are also defined. The identified molecular pathways can now be targeted to develop improved therapeutics.
Project description:Background: Pulmonary endothelial cell (EC) activation is a key factor in acute respiratory distress syndrome (ARDS). In sepsis, increased glycolysis leads to lactate buildup, which induces lysine lactylation (Kla) on histones and other proteins. However, the role of protein lactylation in EC dysfunction during sepsis-induced ARDS remains unclear. Methods: Integrative lactylome and proteome analysis was performed to identify the global lactylome profiling in lung tissues of septic mice. Cut&Tag analysis were used to identify the transcriptional targets of histone H3 lysine 14 lactylation (H3K14la) in ECs. Results: Septic mice exhibited elevated levels of lactate and H3K14la in lung tissues, particularly in pulmonary ECs. Suppressing glycolysis reduced both H3K14la and EC activation, suggesting a link between glycolysis and lactylation. Moreover, H3K14la was found to be enriched at promoter regions of ferroptosis-related genes such as transferrin receptor (TFRC) and solute carrier family 40 member 1 (SLC40A1), which contributed to EC activation and lung injury under septic conditions. Conclusions: We for the first time reported the role of lactate-dependent H3K14 lactylation in regulating EC ferroptosis to promote vascular dysfunction during sepsis-induced lung injury. Our findings suggest that manipulation of glycolysis/H3K14la/ferroptosis axis may provide novel therapeutic approaches for sepsis-associated ARDS.
Project description:We compared differential gene expression in tracheal aspirates collected mechanically ventilated subjects with COVID-19 ARDS to gene expression in tracheal aspirates from: 1) subjects with ARDS from other casues and 2) mechanically ventilated controls without evidence of pulmonary disease.
Project description:Background: COVID-19 has infected more than 100-million worldwide. Children appear less susceptible to COVID-19 and present with milder symptoms. Cases of children with COVID-19 developing clinical features of Kawasaki-disease have been described. Methods: We utilised SWATH-MS proteomics to determine the plasma proteins expressed in healthy children, children with multisystem inflammatory syndrome (MIS-C) and children with COVID-19 induced ARDS. Pathway analyses were performed to determine the affected pathways. Results: 76 proteins were differentially expressed across the groups, with 85 and 52 proteins specific to MIS-C and COVID-19 ARDS. Complement and coagulation activation were implicated in these clinical phenotypes, however there was contribution of FcGR and BCR activation in MIS-C and scavenging of heme and retinoid metabolism in COVID-19 ARDS. Conclusions: We show proteome differences in MIS-C and COVID-ARDS, although both show complement and coagulation dysregulation. The results may be helpful in developing therapeutic targets that could improve the outcomes for these children.
Project description:Acute respiratory distress syndrome (ARDS) is a respiratory failure in critically ill patients, and the molecular mechanisms underlying its pathogenesis and severity are poorly understood. We evaluated mRNA and miRNA in patients with ARDS and elucidated the pathogenesis of ARDS, following mRNA and miRNA integration analysis. Thirty-four ARDS patients were compared with 15 healthy donors. 1233 mRNAs and 6 miRNAs were upregulated and 1580 mRNAs and 13 miRNAs were downregulated in ARDS patients compared healthy donors. In both mRNA and miRNA-targeted mRNA, the canonical pathway analysis showed that PD-1 and PD-L1 cancer immunotherapy pathway was most activated and Th2 pathway was most suppressed. miR-149-3p and several miRNAs were identified as upstream regulators. Integrated analysis of mRNAs and miRNAs showed that T cells were dysfunctional in ARDS patients.
Project description:Acute respiratory distress syndrome (ARDS) is a respiratory failure in critically ill patients, and the molecular mechanisms underlying its pathogenesis and severity are poorly understood. We evaluated mRNA and miRNA in patients with ARDS and elucidated the pathogenesis of ARDS, following mRNA and miRNA integration analysis. Thirty-four ARDS patients were compared with 15 healthy donors. 1233 mRNAs and 6 miRNAs were upregulated and 1580 mRNAs and 13 miRNAs were downregulated in ARDS patients compared healthy donors. In both mRNA and miRNA-targeted mRNA, the canonical pathway analysis showed that PD-1 and PD-L1 cancer immunotherapy pathway was most activated and Th2 pathway was most suppressed. miR-149-3p and several miRNAs were identified as upstream regulators. Integrated analysis of mRNAs and miRNAs showed that T cells were dysfunctional in ARDS patients.
Project description:Cellular senescence is associated with aging but also impacts various physiological and pathological processes such as embryonic development and wound healing. Factors secreted by senescent cells can affect their microenvironment, including local spreading of senescence. Acute severe liver disease is associated with hepatocyte senescence and frequently progresses to multi-organ failure. Why the latter occurs is poorly understood however, the presence of hepatic senescence is associated with poor prognosis and extrahepatic organ failure in acute liver disease. Here, using genetic mouse models of hepatocyte-specific senescence, we demonstrate senescence development in extrahepatic organs and associated organ dysfunction in response to liver senescence. In patients with acute indeterminate hepatitis, the extent of hepatocellular senescence predicts the occurrence of extrahepatic dysfunction, need for liver transplantation and mortality. We identify the Transforming Growth Factor Beta (TGFbeta) pathway as a critical mediator of systemic spread of senescence and TGFbeta inhibition blocks senescence transmission to other organs preventing renal dysfunction. Our results highlight the systemic consequences of organ-specific senescence which, independent of aging, contributes to multi-organ dysfunction.
Project description:Cellular senescence is associated with aging but also impacts various physiological and pathological processes such as embryonic development and wound healing. Factors secreted by senescent cells can affect their microenvironment, including local spreading of senescence. Acute severe liver disease is associated with hepatocyte senescence and frequently progresses to multi-organ failure. Why the latter occurs is poorly understood however, the presence of hepatic senescence is associated with poor prognosis and extrahepatic organ failure in acute liver disease. Here, using genetic mouse models of hepatocyte-specific senescence, we demonstrate senescence development in extrahepatic organs and associated organ dysfunction in response to liver senescence. In patients with acute indeterminate hepatitis, the extent of hepatocellular senescence predicts the occurrence of extrahepatic dysfunction, need for liver transplantation and mortality. We identify the Transforming Growth Factor β (TGFβ) pathway as a critical mediator of systemic spread of senescence and TGFβ inhibition blocks senescence transmission to other organs preventing renal dysfunction. Our results highlight the systemic consequences of organ-specific senescence which, independent of aging, contributes to multi-organ dysfunction.
Project description:The acute respiratory distress syndrome (ARDS) is a common complications of severe COVID-19 and contributes to patient morbidity and mortality. ARDS is a heterogeneous syndrome caused by various insults, and results in acute hypoxemic respiratory failure. Patients with ARDS from COVID-19 may represent a subgroup of ARDS patients with distinct molecular profiles that drive disease outcomes. Here, we hypothesized that longitudinal transcriptomic analysis may identify distinct dynamic pathobiological pathways during COVID-19 ARDS. We identified a patient cohort from an existing ICU biorepository and established three groups for comparison: 1) patients with COVID-19 ARDS that survived hospitalization (COVID survivors, n = 4), 2) patients with COVID-19 ARDS that did not survive hospitalization (COVID non-survivors, n = 5), and 3) patients with ARDS from other causes as a control group (ARDS controls, n = 4). RNA was extracted from peripheral blood mononuclear cells (PBMCs) at 4 time points (Days 1, 3, 7, and 10 following ICU admission) and prepared for RNA sequencing with rRNA depletion and library generation for Illumina. An Illumina NovaSeq X Plus instrument was used to generate 150 base pair paired-end reads, which were aligned to the hg GRCh38.96 reference genome using HiSAT2. Differential expression analysis was performed with DESeq2.