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J Biol Chem ; 297(5): 101315, 2021 11.
Article in English | MEDLINE | ID: covidwho-1472025


Coagulopathy is associated with both inflammation and infection, including infections with novel severe acute respiratory syndrome coronavirus-2, the causative agent Coagulopathy is associated with both inflammation and infection, including infection with novel severe acute respiratory syndrome coronavirus-2, the causative agent of COVID-19. Clot formation is promoted via cAMP-mediated secretion of von Willebrand factor (vWF), which fine-tunes the process of hemostasis. The exchange protein directly activated by cAMP (EPAC) is a ubiquitously expressed intracellular cAMP receptor that plays a regulatory role in suppressing inflammation. To assess whether EPAC could regulate vWF release during inflammation, we utilized our EPAC1-null mouse model and revealed increased secretion of vWF in endotoxemic mice in the absence of the EPAC1 gene. Pharmacological inhibition of EPAC1 in vitro mimicked the EPAC1-/- phenotype. In addition, EPAC1 regulated tumor necrosis factor-α-triggered vWF secretion from human umbilical vein endothelial cells in a manner dependent upon inflammatory effector molecules PI3K and endothelial nitric oxide synthase. Furthermore, EPAC1 activation reduced inflammation-triggered vWF release, both in vivo and in vitro. Our data delineate a novel regulatory role for EPAC1 in vWF secretion and shed light on the potential development of new strategies to control thrombosis during inflammation.

Endothelial Cells/metabolism , Guanine Nucleotide Exchange Factors/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphatidylinositol 3-Kinases/metabolism , von Willebrand Factor/metabolism , Animals , COVID-19/metabolism , Disease Models, Animal , Guanine Nucleotide Exchange Factors/deficiency , Guanine Nucleotide Exchange Factors/genetics , Inflammation/metabolism , Mice , Mice, Knockout
Nat Commun ; 12(1): 4636, 2021 07 30.
Article in English | MEDLINE | ID: covidwho-1347938


Chikungunya virus (CHIKV) is a reemerging mosquito-borne virus that causes swift outbreaks. Major concerns are the persistent and disabling polyarthralgia in infected individuals. Here we present the results from a first-in-human trial of the candidate simian adenovirus vectored vaccine ChAdOx1 Chik, expressing the CHIKV full-length structural polyprotein (Capsid, E3, E2, 6k and E1). 24 adult healthy volunteers aged 18-50 years, were recruited in a dose escalation, open-label, nonrandomized and uncontrolled phase 1 trial (registry NCT03590392). Participants received a single intramuscular injection of ChAdOx1 Chik at one of the three preestablished dosages and were followed-up for 6 months. The primary objective was to assess safety and tolerability of ChAdOx1 Chik. The secondary objective was to assess the humoral and cellular immunogenicity. ChAdOx1 Chik was safe at all doses tested with no serious adverse reactions reported. The vast majority of solicited adverse events were mild or moderate, and self-limiting in nature. A single dose induced IgG and T-cell responses against the CHIKV structural antigens. Broadly neutralizing antibodies against the four CHIKV lineages were found in all participants and as early as 2 weeks after vaccination. In summary, ChAdOx1 Chik showed excellent safety, tolerability and 100% PRNT50 seroconversion after a single dose.

Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Chikungunya Fever/immunology , Chikungunya virus/immunology , Viral Vaccines/immunology , Adolescent , Adult , Chikungunya Fever/prevention & control , Chikungunya Fever/virology , Chikungunya virus/classification , Chikungunya virus/physiology , Cytokines/immunology , Cytokines/metabolism , Enzyme-Linked Immunosorbent Assay , Fatigue/chemically induced , Female , Headache/chemically induced , Humans , Immunoglobulin G/immunology , Injections, Intramuscular , Male , Middle Aged , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Vaccination/methods , Viral Vaccines/administration & dosage , Viral Vaccines/adverse effects , Young Adult
Microorganisms ; 9(6)2021 Jun 17.
Article in English | MEDLINE | ID: covidwho-1273484


The COVID-19 pandemic continues to affect millions of people worldwide. Although SARS-CoV-2 is a respiratory virus, there is growing concern that the disease could cause damage and pathology outside the lungs, including in the genital tract. Studies suggest that SARS-CoV-2 infection can damage the testes and reduce testosterone levels, but the underlying mechanisms are unknown and evidence of virus replication in testicular cells is lacking. We infected golden Syrian hamsters intranasally, a model for mild human COVID-19, and detected viral RNA in testes samples without histopathological changes up to one month post-infection. Using an ex vivo infection model, we detected SARS-CoV-2 replication in hamster testicular cells. Taken together, our data raise the possibility that testes damage observed in severe cases of COVID-19 could be partly explained by direct SARS-CoV-2 infection of the testicular cells.