Detailed stratified GWAS analysis for severe COVID-19 in four European populations

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

Increased risk of severe clinical course of COVID-19 in carriers of HLA-C*04:01

BACKGROUND

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there has been increasing urgency to identify pathophysiological characteristics leading to severe clinical course in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human leukocyte antigen alleles (HLA) have been suggested as potential genetic host factors that affect individual immune response to SARS-CoV-2. We sought to evaluate this hypothesis by conducting a multicenter study using HLA sequencing.

METHODS

We analyzed the association between COVID-19 severity and HLAs in 435 individuals from Germany (n = 135), Spain (n = 133), Switzerland (n = 20) and the United States (n = 147), who had been enrolled from March 2020 to August 2020. This study included patients older than 18 years, diagnosed with COVID-19 and representing the full spectrum of the disease. Finally, we tested our results by meta-analysing data from prior genome-wide association studies (GWAS).

FINDINGS

We describe a potential association of HLA-C*04:01 with severe clinical course of COVID-19. Carriers of HLA-C*04:01 had twice the risk of intubation when infected with SARS-CoV-2 (risk ratio 1.5 [95% CI 1.1-2.1], odds ratio 3.5 [95% CI 1.9-6.6], adjusted p-value = 0.0074). These findings are based on data from four countries and corroborated by independent results from GWAS. Our findings are biologically plausible, as HLA-C*04:01 has fewer predicted bindings sites for relevant SARS-CoV-2 peptides compared to other HLA alleles.

INTERPRETATION

HLA-C*04:01 carrier state is associated with severe clinical course in SARS-CoV-2. Our findings suggest that HLA class I alleles have a relevant role in immune defense against SARS-CoV-2.

FUNDING

Funded by Roche Sequencing Solutions, Inc.

Metformin Attenuates ROS via FOXO3 Activation in Immune Cells

Forkhead box O 3 (FOXO3) is a transcription factor involved in cell metabolism, inflammation and longevity. Here, we investigated if metformin can activate FOXO3 in human immune cells and affects the subsequent level of reactive oxygen/nitrogen species (ROS/RNS) in immune cells. AMP-activated protein kinase (AMPK) and FOXO3 activation were investigated by immunoblot or flow cytometry (FC) analysis, respectively. FOXO3 target gene expression was quantified by real-time PCR. ROS/RNS measurement using dichlorodihydrofluorescein diacetate (DCFH-DA) dye was investigated by FC. The role of the FOXO3 single nucleotide polymorphisms (SNPs) rs12212067, rs2802292 and rs12206094 on ROS/RNS production was studied using allelic discrimination PCR. Metformin induced activation of AMPK (pT172) and FOXO3 (pS413). ROS/RNS level was reduced in immune cells after metformin stimulation accompanied by induction of the FOXO3 targets mitochondrial superoxide dismutase and cytochrome c. Studies in Foxo3 deficient (Foxo3-/- ) mouse splenocytes confirmed that metformin mediates its effects via Foxo3 as it attenuates ROS/RNS in myeloid cells of wildtype (WT) but not of Foxo3-/- mice. Our results suggest that FOXO3 can be activated by metformin leading to reduced ROS/RNS level in immune cells. This may add to the beneficial clinical effects of metformin observed in large cohort studies on longevity, cardiovascular and cancer risk.

Knockdown of Indy/CeNac2 extends Caenorhabditis elegans life span by inducing AMPK/aak-2

Reducing the expression of the Indy (Acronym for ‘I'm Not Dead, Yet’) gene in lower organisms promotes longevity and leads to a phenotype that resembles various aspects of caloric restriction. In C. elegans, the available data on life span extension is controversial. Therefore, the aim of this study was to determine the role of the C. elegans INDY homolog CeNAC2 in life span regulation and to delineate possible molecular mechanisms. siRNA against Indy/CeNAC2 was used to reduce expression of Indy/CeNAC2. Mean life span was assessed in four independent experiments, as well as whole body fat content and AMPK activation. Moreover, the effect of Indy/CeNAC2 knockdown in C. elegans with inactivating variants of AMPK (TG38) was studied. Knockdown of Indy/CeNAC2 increased life span by 22 ± 3% compared to control siRNA treated C. elegans, together with a decrease in whole body fat content by ~50%. Indy/CeNAC2 reduction also increased the activation of the intracellular energy sensor AMPK/aak2. In worms without functional AMPK/aak2, life span was not extended when Indy/CeNAC2 was reduced. Inhibition of glycolysis with deoxyglucose, an intervention known to increase AMPK/aak2 activity and life span, did not promote longevity when Indy/CeNAC2 was knocked down. Together, these data indicate that reducing the expression of Indy/CeNAC2 increases life span in C. elegans, an effect mediated at least in part by AMPK/aak2.

Adiponectin attenuates profibrotic extracellular matrix remodeling following cardiac injury by up-regulating matrix metalloproteinase 9 expression in mice

Adiponectin (APN) is a multifunctional adipocytokine that inhibits myocardial fibrosis, dilatation, and left ventricular (LV) dysfunction after myocardial infarction (MI). Coxsackievirus B3 (CVB3) myocarditis is associated with intense extracellular matrix (ECM) remodeling which might progress to dilated cardiomyopathy. Here, we investigated in experimental CVB3 myocarditis whether APN inhibits adverse ECM remodeling following cardiac injury by affecting matrix metalloproteinase (MMP) expression. Cardiac injury was induced by CVB3 infection in APN knockout (APN-KO) and wild-type (WT) mice. Expression and activity of MMPs was quantified by qRT-PCR and zymography, respectively. Activation of protein kinases was assessed by immunoblot. In cardiac myocytes and fibroblasts APN up-regulates MMP-9 expression via activation of 5' adenosine monophosphate-activated protein kinase (AMPK) and extracellular signal-regulated kinase (ERK)1/2 which function as master regulators of inflammation-induced MMP-9 expression. Correspondingly, APN further increased up-regulation of MMP-9 expression triggered by tumor necrosis factor (TNF)α, lipopolysaccharide (LPS) and R-848 in cardiac fibroblasts. In vivo, compared to WT mice cardiac MMP-9 activity and serum levels of carboxy-terminal telopeptide of type I collagen (ICTP) were attenuated in APN-KO mice in subacute (day 7 p.i.) CVB3 myocarditis. Moreover, on day 3 and day 7 post CVB3 infection splenic MMP-9 expression was diminished in APN-KO mice correlating with attenuated myocardial immune cell infiltration in subacute CVB3 myocarditis. These results indicate that APN attenuates adverse cardiac remodeling following cardiac injury by up-regulating MMP-9 expression in cardiac and immune cells. Thus, APN mediates intensified collagen cleavage that might explain inhibition of LV fibrosis and dysfunction.

FOXO3A acts as immune response modulator in human virus-negative inflammatory cardiomyopathy

OBJECTIVE

Inflammatory cardiomyopathy is characterised by inflammatory infiltrates leading to cardiac injury, left ventricular (LV) dilatation and reduced LV ejection fraction (LVEF). Several viral pathogens and autoimmune phenomena may cause cardiac inflammation.The effects of the gain of function FOXO3A single-nucleotide polymorphism (SNP) rs12212067 on inflammation and outcome were studied in a cohort of patients with inflammatory dilated cardiomyopathy (DCMi) in relation to cardiac viral presence.

METHODS

Distribution of the SNP was determined in virus-positive and virus-negative DCMi patients and in control subjects without myocardial pathology. Baseline and outcome data were compared in 221 virus-negative patients with detection of cardiac inflammation and reduced LVEF according to their carrier status of the SNP.

RESULTS

Distribution of SNP rs12212067 did not differ between virus-positive (n=22, 19.3%), virus-negative (n=45, 20.4 %) and control patients (n=18, 23.4 %), indicating the absence of susceptibility for viral infection or inflammation per se (p=0.199). Patients in the virus-negative DCMi group were characterised by reduced LVEF 35.5% (95% CI) 33.5 to 37.4) and increased LVEDD (LV end-diastolic diameter) 59.8 mm (95% CI 58.5 to 61.2). Within the group, SNP and non-SNP carriers had similarly impaired LVEF 39.2% (95% CI 34.3% to 44.0%) vs 34.5% (95% CI 32.4 to 36.5), p=0.083, and increased LVEDD 58.9 mm (95% CI 56.3 to 61.5) vs 60.1 mm (95% CI 58.6 to 61.6), p=0.702, respectively. The number of inflammatory infiltrates was not different in both SNP groups at baseline. Outcome after 6 months showed a significant improvement in LVEF and clinical symptoms in SNP rs12212067 carriers 50.9% (95% CI 45.4 to 56.3) versus non-SNP carriers 41.7% (95% CI 39.2 to 44.2), p≤0.01. The improvement in clinical symptoms and LVEF was associated with a significant reduction in cardiac inflammation (ΔCD45RO⁺ p≤0.05; ΔMac-1⁺ p≤0.05; ΔLFA-1⁺ p≤0.01; ΔCD54⁺ p≤0.01) in the SNP cohort versus non-SNP cohort, respectively. Subgroup analyses identified ΔMac-1⁺, ΔLFA-1⁺, ΔCD3⁺ and Δperforin⁺ as predictors for improvement in cardiac function in SNP-positive patients.

CONCLUSION

FOXO3A might act as modulator of the cardiac immune response, diminishing cardiac inflammation and injury in pathogen-negative DCMi.

Novel effects of Foxo3a on immune system and cardiac remodeling after myocardial infarction

Background

Fibroblast/myofibroblast transdifferentiation following acute cardiac injury (MI) is a major mechanism of scar formation and adverse remodeling regulated by TGFβ/SMAD3 signaling. Myofibroblasts represent phenotypically modulated cells characterized by α-smooth muscle actin (α-SMA) and constitute the main source of extracellular matrix proteins such as collagen type I in the healing infarct wound. Moreover, the recruitment of a specific monocyte/macrophages subset (Ly6Chigh and Ly6Clow) control the healing process in the infarcted wound. The forkhead transcription factor FOXO3a has recently been shown to inhibit cardiac hypertrophy by different stressors and is involved in the immune response following injury.

Purpose

We hypothesized that FOXO3a, a key regulator of cell differentiation, cell cycle and size as well as the stress response, might inhibit matricellular remodeling following myocardial infarction by regulating transdifferentiation of fibroblasts into myofibroblasts. Moreover, we hypothesized that Foxo3a−/− mice favor the recruitment of monocytes of the type Ly6Clow leading to an anti-inflammatory profile and thus the remodeling after injury.

Methods

Acute myocardial infarction was induced in FOXO3−/− and WT mice (FVB background) by permanent LAD ligation. The myocardial infarction size was determined via ECHO. Myofibroblast trans-differentiation and fibrosis markers were analyzed by QT-PCR and protein analysis. The differentiation of macrophages studied via FACS. IP/IF and Western blotting were used to test for a direct interaction between FOXO3a and SMAD3 in vitro.

Results

FOXO3a−/− mice showed significantly higher survival rates compared to WT littermates. Myocardial inflammation (Mac-1, LFA, CD3, CD45), injury markers such as Troponin T were similar in both groups on day 4 post-MI. Myocardial expression of alpha smooth muscle actin (ASMA) and Collagen1A1 (Col1A1), as well as numbers of cardiac CD11b+/F4–80+/Ly6clow macrophages was significantly enhanced in FOXO3a−/− mice 15 days post infarction. Moreover, Foxo3a−/− mice showed larger fibrotic areas following MI. Mechanistically, immunoprecipitation showed direct interaction of FOXO3a with SMAD3a that was enhanced following activation of the transcription factor leading to diminished SMAD3 downstream gene expression.

Conclusion

Our results indicate that FOXO3a acts as a direct inhibitor of TGF-β regulated myofibroblast differentiation and matrix remodeling via FOXO3a-SMAD3 interaction following MI. Moreover, a Foxo3a deficiency might lead to the recruitment of monocytes type Ly6Clow leading to an anti-inflammatory profile in the infarct wound. Therefore, FOXO3a collectively regulates cardiac hypertrophy and fibrosis/scar formation following MI. Thus, targeting the FOXO3a-SMAD3 signaling axis might be of future therapeutic interest.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Resaerch Foundation

First effectiveness data of lenvatinib and pembrolizumab as first-line therapy in advanced anaplastic thyroid cancer: a retrospective cohort study

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare and aggressive neoplasm. We still lack effective treatment options, so survival rates remain very low. Here, we aimed to evaluate the activity of the combination of lenvatinib and pembrolizumab as systemic first-line therapy in ATC.

METHODS

In a retrospective analysis, we investigated the activity and tolerability of combined lenvatinib (starting dose 14 to 24 mg daily) and pembrolizumab (200 mg every three weeks) as first-line therapy in an institutional cohort of ATC patients.

RESULTS

Five patients with metastatic ATC received lenvatinib and pembrolizumab as systemic first-line therapy. The median progression-free survival was 4.7 (range 0.8-5.9) months, and the median overall survival was 6.3 (range 0.8-not reached) months. At the first follow-up, one patient had partial response, three patients had stable disease, and one patient was formally not evaluable due to interference of assessment by concomitant acute infectious thyroiditis. This patient was then stable for more than one year and was still on therapy at the data cutoff without disease progression. Further analyses revealed deficient DNA mismatch repair, high CD8+ lymphocyte infiltration, and low macrophage infiltration in this patient. Of the other patients, two had progressive disease after adverse drug reactions and therapy de-escalation, and two died after the first staging. For all patients, the PD-L1 combined positive score ranged from 12 to 100%.

CONCLUSIONS

The combination of lenvatinib and pembrolizumab was effective and moderately tolerated in treatment-naïve ATC patients with occasional long-lasting response. However, we could not confirm the exceptional responses for this combination therapy reported before in pretreated patients.