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1.
EBioMedicine ; 79: 103999, 2022 May.
Article in English | MEDLINE | ID: covidwho-1796985

ABSTRACT

BACKGROUND: Neurological symptoms such as cognitive decline and depression contribute substantially to post-COVID-19 syndrome, defined as lasting symptoms several weeks after initial SARS-CoV-2 infection. The pathogenesis is still elusive, which hampers appropriate treatment. Neuroinflammatory responses and neurodegenerative processes may occur in absence of overt neuroinvasion. METHODS: Here we determined whether intranasal SARS-CoV-2 infection in male and female syrian golden hamsters results in persistent brain pathology. Brains 3 (symptomatic) or 14 days (viral clearance) post infection versus mock (n = 10 each) were immunohistochemically analyzed for viral protein, neuroinflammatory response and accumulation of tau, hyperphosphorylated tau and alpha-synuclein protein. FINDINGS: Viral protein in the nasal cavity led to pronounced microglia activation in the olfactory bulb beyond viral clearance. Cortical but not hippocampal neurons accumulated hyperphosphorylated tau and alpha-synuclein, in the absence of overt inflammation and neurodegeneration. Importantly, not all brain regions were affected, which is in line with selective vulnerability. INTERPRETATION: Thus, despite the absence of virus in brain, neurons develop signatures of proteinopathies that may contribute to progressive neuronal dysfunction. Further in depth analysis of this important mechanism is required. FUNDING: Federal Ministry of Health (BMG; ZMV I 1-2520COR501), Federal Ministry of Education and Research (BMBF 01KI1723G), Ministry of Science and Culture of Lower Saxony in Germany (14 - 76103-184 CORONA-15/20), German Research Foundation (DFG; 398066876/GRK 2485/1), Luxemburgish National Research Fund (FNR, Project Reference: 15686728, EU SC1-PHE-CORONAVIRUS-2020 MANCO, no > 101003651).


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Brain , COVID-19/complications , Cricetinae , Female , Humans , Inflammation , Male , Neurons , Viral Proteins , alpha-Synuclein
2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322033

ABSTRACT

SARS-CoV-2 infection is associated with increased morbidities in men compared to women. Androgens are believed to play an important role in SARS-CoV-2 pathogenesis in men due to the postulated androgen-dependency of ACE2 and TMPRSS2. However, it is yet unclear whether the sex bias is mediated by SARS-CoV-2 infection itself or by other confounding factors. Here, using the golden hamster model, we show that SARS-CoV-2 infection attacks reproductive organs, causes massive dysregulation of sex hormones and induces elevated transcription of the androgen-to-estrogen converting enzyme aromatase CYP19A1 in the lung. In male hamsters, SARS-CoV-2 infection causes severely depleted testosterone and highly elevated estradiol levels. In female hamsters, SARS-CoV-2 infection causes reduced estradiol levels. Hormonal dysregulation in infected animals is followed by severe weight loss compared to control groups treated with poly(I:C) or PBS. Lungs of SARS-CoV-2 infected animals present abundant CYP19A1 expression in the endothelium and in macrophages, particularly in males. Prominent CYP19A1 expression in endothelial cells and macrophages was verified in lung sections of deceased Covid-19 males compared to females. Our results demonstrate that SARS-CoV-2 infection leads to massive dysregulation of sex hormones, which may increase the risk for sex-specific disease outcome particularly in combination with comorbidities. These findings provide insights into the complex metabolic cross talk between SARS-CoV-2 infection and sex hormones.

3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-297003

ABSTRACT

Male sex belongs to one of the major risk factors for severe COVID-19 outcome. However, underlying mechanisms that could affect sex dependent disease outcome are yet unknown. Here, we identified the CYP19A1 gene encoding for the testosterone-to-estradiol metabolizing enzyme CYP19A1 (alias aromatase) as a male abundant host factor that contributes to worsened disease outcome in SARS-CoV-2 infected male hamsters. Pulmonary CYP19A1 transcription is further elevated upon viral infection in males correlating with reduced testosterone and increased estradiol levels. Dysregulated circulating sex hormone levels in male golden hamsters are associated with reduced lung function compared to females. Treatment of SARS-CoV-2 infected hamsters with letrozole, a clinically approved CYP19A1 inhibitor, supported recovery of dysregulated plasma sex hormone levels and was associated with improved lung function and health in male but not female animals compared to placebo controls. Whole human exome sequencing data analysis using a Machine Learning approach revealed a CYP19A1 activity increasing mutation being associated with the development of severe COVID-19 for men. In human autopsy-derived lungs CYP19A1 was expressed to higher levels in men who died of COVID-19, at a time point when most viral RNA was cleared. Our findings highlight the role of the lung as a yet unrecognized but critical organ regulating metabolic responses upon respiratory virus infection. Furthermore, inhibition of CYP19A1 by the clinically approved drug letrozole may pose a new therapeutic strategy to reduce poor long-term COVID-19 outcome.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296455

ABSTRACT

Obesity increases the risk for poor outcome in patients with coronavirus disease-19 (COVID-19). However, the role of adipose tissue for viral propagation and potential metabolic implications are not understood. We detected SARS-CoV-2 in adipose tissue of overweight but not lean male COVID-19 patients. SARS-CoV-2 replicates to high titres in cultured mature adipocytes, a process depending on lipid accumulation and mobilization. After intranasal inoculation, we observed high viral replication in fat depots of Golden Syrian hamsters, demonstrating dissemination from the respiratory tract and subsequent propagation in adipose tissue. Following induction of pro-inflammatory responses, expression of de novo lipogenesis enzymes was suppressed in adipose tissue. This specific down-regulation was reflected by lipidomic alterations in plasma of SARS-CoV-2 infected hamsters as well as in hospitalized COVID-19 patients. Overall, our study highlights that adipose tissue is an important site of SARS-CoV-2 replication, contributing to dysregulation of systemic lipid metabolism.<br><br>Funding: This study was supported by a rapid response grant from the Federal Ministry of Health (BMG;ZMV I 1-2520COR501 to GG), by DFG grants SCHE522/4-1 (LS) and SFB1328, project- ID:335447727 (JH). As part of the National Network University Medicine (NUM) funded by the Federal Ministry of Education and Research (BMBF, Germany), this work was funded within the research consortium DEFEAT PANDEMIcs, grant number 01KX2021 (FH, PL, KP, BO).<br><br>Declaration of Interests: The authors declare no competing interests.<br><br>Ethics Approval Statement: The Ethics Committee of the Hamburg Chamber of Physicians reviewed and approved the studies (PV7311, 2020-10353-BO-ff, WF-051/20, WF-053/20). For the preparation of primary human white adipocytes, biopsies of subcutaneous and visceral adipose tissues were taken during bariatric surgery at the Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf. All participants signed an informed consent and the study was approved by the Ethics Committee of the Hamburg Chamber of Physicians (PV4889).

6.
Front Immunol ; 12: 640842, 2021.
Article in English | MEDLINE | ID: covidwho-1207697

ABSTRACT

Neutrophil extracellular traps (NETs) have been identified as one pathogenetic trigger in severe COVID-19 cases and therefore well-described animal models to understand the influence of NETs in COVID-19 pathogenesis are needed. SARS-CoV-2 infection causes infection and interstitial pneumonia of varying severity in humans and COVID-19 models. Pulmonary as well as peripheral vascular lesions represent a severe, sometimes fatal, disease complication of unknown pathogenesis in COVID-19 patients. Furthermore, neutrophil extracellular traps (NETs), which are known to contribute to vessel inflammation or endothelial damage, have also been shown as potential driver of COVID-19 in humans. Though most studies in animal models describe the pulmonary lesions characterized by interstitial inflammation, type II pneumocyte hyperplasia, edema, fibrin formation and infiltration of macrophages and neutrophils, detailed pathological description of vascular lesions or NETs in COVID-19 animal models are lacking so far. Here we report different types of pulmonary vascular lesions in the golden Syrian hamster model of COVID-19. Vascular lesions included endothelialitis and vasculitis at 3 and 6 days post infection (dpi), and were almost nearly resolved at 14 dpi. Importantly, virus antigen was present in pulmonary lesions, but lacking in vascular alterations. In good correlation to these data, NETs were detected in the lungs of infected animals at 3 and 6 dpi. Hence, the Syrian hamster seems to represent a useful model to further investigate the role of vascular lesions and NETs in COVID-19 pathogenesis.


Subject(s)
COVID-19/pathology , Disease Models, Animal , Extracellular Traps/immunology , Lung/pathology , SARS-CoV-2/pathogenicity , Vasculitis/pathology , Animals , COVID-19/immunology , COVID-19/virology , Cricetinae , Lung/immunology , Lung/virology , Mesocricetus , Vasculitis/immunology , Viral Proteins/metabolism
7.
Cell Rep ; 31(3): 107549, 2020 04 21.
Article in English | MEDLINE | ID: covidwho-100496

ABSTRACT

Importin-α adaptor proteins orchestrate dynamic nuclear transport processes involved in cellular homeostasis. Here, we show that importin-α3, one of the main NF-κB transporters, is the most abundantly expressed classical nuclear transport factor in the mammalian respiratory tract. Importin-α3 promoter activity is regulated by TNF-α-induced NF-κB in a concentration-dependent manner. High-level TNF-α-inducing highly pathogenic avian influenza A viruses (HPAIVs) isolated from fatal human cases harboring human-type polymerase signatures (PB2 627K, 701N) significantly downregulate importin-α3 mRNA expression in primary lung cells. Importin-α3 depletion is restored upon back-mutating the HPAIV polymerase into an avian-type signature (PB2 627E, 701D) that can no longer induce high TNF-α levels. Importin-α3-deficient mice show reduced NF-κB-activated antiviral gene expression and increased influenza lethality. Thus, importin-α3 plays a key role in antiviral immunity against influenza. Lifting the bottleneck in importin-α3 availability in the lung might provide a new strategy to combat respiratory virus infections.


Subject(s)
Influenza A virus/immunology , Influenza, Human/immunology , Orthomyxoviridae Infections/immunology , alpha Karyopherins/biosynthesis , A549 Cells , Animals , Cell Line, Tumor , Chlorocebus aethiops , Down-Regulation , Female , HEK293 Cells , Humans , Influenza, Human/genetics , Influenza, Human/virology , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/virology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Vero Cells , alpha Karyopherins/genetics , alpha Karyopherins/immunology
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