Project description:Obesity is a risk factor for developing severe COVID-19. However, the mechanism underlying obesity-accelerated COVID-19 remains unclear. Here, we report results from a study in which K18-hACE2 mice were fed an obesity-inducing western diet (WD) for over 3 months before intranasal infection with SARS-CoV2. After infection, the WD-fed K18-hACE2 mice lost more body weight and had more severe lung inflammation than normal chow (NC)-fed mice. Bulk RNAseq analysis of lungs and adipose tissue revealed that a diverse landscape of various immune cells, inflammatory markers, and pathways are upregulated in obese COVID-19 patients or the WD-fed K18-hACE2 mice when compared with their respective control groups. When compared with infected NC-fed mice in the lung, the infected WD-fed mice had upregulation of IL-6, a well-established marker for severe COVID-19. These results indicate that obesity-accelerated severe COVID-19 caused by SARS-CoV-2 infection in the K18-hACE2 mouse model can be used for dissecting the cellular and molecular mechanisms underlying pathogenesis. Furthermore, in the transcriptome analysis of the lung and adipose tissue obtained from deceased COVID-19 patients, we found upregulation of an array of genes and pathways associated with Inflammation. Both the K18-hACE2 mouse model and human COVID-19 patient data support a link between inflammation and an obesity-accelerated COVID-19 disease phenotype.
Project description:Although most SARS-CoV-2-infected individuals experience mild COVID-19, some patients suffer from severe COVID-19, which is accompanied by acute respiratory distress syndrome and systemic inflammation. To identify factors driving severe progression of COVID-19, we performed single-cell RNA-seq using peripheral blood mononuclear cells (PBMCs) obtained from healthy donors, patients with mild or severe COVID-19, and patients with severe influenza. Patients with COVID-19 exhibited hyper-inflammatory signatures across all types of cells among PBMCs, particularly upregulation of the TNF/IL-1beta-driven inflammatory response as compared to severe influenza. In classical monocytes from patients with severe COVID-19, type I IFN response co-existed with the TNF/IL-1beta-driven inflammation, and this was not seen in patients with milder COVID-19 infection. Based on this, we propose that the type I IFN response exacerbates inflammation in patients with severe COVID-19 infection.
Project description:Manuscript describes the daily dynamics of transcriptional responses in whole blood, from acute to convalescent phase, in severe and non-severe COVID-19 patients.
Project description:Obesity is considered a multifactorial disorder with high heritability (50-75%), probably higher in early-onset and severe cases. Although rare monogenic forms and several genes and regions of susceptibility, including CNVs, have been defined, the genetic causes underlying the disease still remain largely unknown. We aimed to identify novel genetic and genomic abnormalities in a cohort of Spanish children with severe non-syndromic early-onset obesity (EOO). We obtained molecular karyotypes of 157 children with EOO. Large and rare CNVs were validated and segregated in the family. A higher burden of duplication-type CNVs was detected in EOO patients versus controls (OR=1.85, p-value=0.008).
Project description:In order to identify differentially abundant proteins, human plasma samples from COVID-19 patients with either a mild or moderate (MM) or a critical or severe (CS) disease course from acute phase of infection were analyzed on antibody microarrays 998 different proteins by 1,425 antibodies.
Project description:In order to identify differentially abundant proteins, human plasma samples from COVID-19 patients with either a mild or moderate (MM) or a critical or severe (CS) disease course from the acute phases of infection were analyzed on antibody microarrays targeting 351 different proteins by 517 antibodies.
Project description:While critical for host defense, innate immune cells are also pathologic drivers of acute respiratory distress syndrome (ARDS). Innate immune dynamics during COVID-19 ARDS, compared to ARDS from other respiratory pathogens, is unclear. Moreover, mechanisms underlying beneficial effects of dexamethasone during severe COVID-19 remain elusive. Using scRNA-seq and plasma proteomics, we discovered that compared to bacterial ARDS, COVID-19 was associated with expansion of distinct neutrophil states characterized by interferon (IFN) and prostaglandin (PG) signalling. Dexamethasone during severe COVID-19 depleted circulating neutrophils, altered IFNactive neutrophils, downregulated interferon-stimulated gene, and activated IL1R2+ve neutrophils. Dexamethasone also expanded immunosuppressive immature neutrophils and remodeled cellular interactions by changing neutrophils from information receivers into information providers. Male patients had higher proportions of IFNactive neutrophils, preferential steroid-induced immature neutrophil expansion, and possibly different effects on outcome. Our single-cell atlas (www.biernaskielab.ca/COVID_neutrophil) defines COVID-19-enriched neutrophil states and molecular mechanisms of dexamethasone action to develop targeted immunotherapies for severe COVID-19.
Project description:The objective of this experiment was to compare the transcriptomic profile (NanoString platform) of peripheral blood mononuclear cells (PBMCs) from COVID-19 patients with mild disease, and patients with severe COVID-19 with and without dexamethasone treatment, and healthy controls. We analyzed PBMCs from 4 mild COVID patients, 3 severe COVID patients,4 severe COVID patients treated with dexamethasone, and 5 healthy controls