Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 206
Filter
1.
Dis Model Mech ; 14(1)2021 01 22.
Article in English | MEDLINE | ID: covidwho-1910406

ABSTRACT

Human lifespan is now longer than ever and, as a result, modern society is getting older. Despite that, the detailed mechanisms behind the ageing process and its impact on various tissues and organs remain obscure. In general, changes in DNA, RNA and protein structure throughout life impair their function. Haematopoietic ageing refers to the age-related changes affecting a haematopoietic system. Aged blood cells display different functional aberrations depending on their cell type, which might lead to the development of haematologic disorders, including leukaemias, anaemia or declining immunity. In contrast to traditional bulk assays, which are not suitable to dissect cell-to-cell variation, single-cell-level analysis provides unprecedented insight into the dynamics of age-associated changes in blood. In this Review, we summarise recent studies that dissect haematopoietic ageing at the single-cell level. We discuss what cellular changes occur during haematopoietic ageing at the genomic, transcriptomic, epigenomic and metabolomic level, and provide an overview of the benefits of investigating those changes with single-cell precision. We conclude by considering the potential clinical applications of single-cell techniques in geriatric haematology, focusing on the impact on haematopoietic stem cell transplantation in the elderly and infection studies, including recent COVID-19 research.


Subject(s)
Aging/physiology , Hematopoietic System/physiology , Single-Cell Analysis/methods , Aging/genetics , Animals , Bone Marrow/physiology , DNA Damage , Epigenome , Glycolysis , Hematopoietic Stem Cell Transplantation , Humans , Mutation , Transcriptome
2.
Transbound Emerg Dis ; 68(6): 3443-3452, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1526424

ABSTRACT

The recently emerged novel coronavirus, SARS-CoV-2, is phylogenetically related to bat coronaviruses (CoVs), specifically SARS-related CoVs from the Eurasian bat family Rhinolophidae. As this human pandemic virus has spread across the world, the potential impacts of SARS-CoV-2 on native North American bat populations are unknown, as is the ability of North American bats to serve as reservoirs or intermediate hosts able to transmit the virus to humans or to other animal species. To help determine the impacts of the pandemic virus on North American bat populations, we experimentally challenged big brown bats (Eptesicus fuscus) with SARS-CoV-2 under BSL-3 conditions. We inoculated the bats both oropharyngeally and nasally, and over the ensuing three weeks, we measured infectivity, pathology, virus concentrations in tissues, oral and rectal virus excretion, virus transmission, and clinical signs of disease. We found no evidence of SARS-CoV-2 infection in any examined bat, including no viral excretion, no transmission, no detectable virus in tissues, and no signs of disease or pathology. Based on our findings, it appears that big brown bats are resistant to infection with the SARS-CoV-2. The potential susceptibility of other North American bat species to SARS-CoV-2 remains to be investigated.


Subject(s)
COVID-19 , Chiroptera , Coronaviridae , Animals , COVID-19/veterinary , Humans , North America/epidemiology , Phylogeny , SARS-CoV-2
3.
Biochem Mosc Suppl B Biomed Chem ; 15(2): 147-152, 2021.
Article in English | MEDLINE | ID: covidwho-1467675

ABSTRACT

The review considers complex, controversial, and individual effects of heparin and its derivatives on the bone and circulatory systems in dependence of the dose, the state of the cells and tissues of the recipient. General data on the anticoagulant activity of heparin and its derivatives are presented; special attention is paid to the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis. We also discuss the ability of heparin to bind osteogenic and angiogenic biomolecules in the context of the development of systems for their delivery and sustained controlled release and propose a schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering.

4.
Vox Sang ; 116(8): 849-861, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1402984

ABSTRACT

Growing evidence suggests that ABO blood group may play a role in the immunopathogenesis of SARS-CoV-2 infection, with group O individuals less likely to test positive and group A conferring a higher susceptibility to infection and propensity to severe disease. The level of evidence supporting an association between ABO type and SARS-CoV-2/COVID-19 ranges from small observational studies, to genome-wide-association-analyses and country-level meta-regression analyses. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues (notably endothelium). There are several hypotheses to explain the differences in SARS-CoV-2 infection by ABO type. For example, anti-A and/or anti-B antibodies (e.g. present in group O individuals) could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell infection. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinins (e.g. present in group O and group B individuals), which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entry into lung epithelial cells. ABO type-associated variations in angiotensin-converting enzyme-1 activity and levels of von Willebrand factor (VWF) and factor VIII could also influence adverse outcomes, notably in group A individuals who express high VWF levels. In conclusion, group O may be associated with a lower risk of SARS-CoV-2 infection and group A may be associated with a higher risk of SARS-CoV-2 infection along with severe disease. However, prospective and mechanistic studies are needed to verify several of the proposed associations. Based on the strength of available studies, there are insufficient data for guiding policy in this regard.


Subject(s)
ABO Blood-Group System , COVID-19 , ABO Blood-Group System/genetics , Blood Grouping and Crossmatching , Humans , Prospective Studies , SARS-CoV-2
6.
Int J Mol Sci ; 21(24)2020 Dec 17.
Article in English | MEDLINE | ID: covidwho-1383876

ABSTRACT

Cell-cell fusion between eukaryotic cells is a general process involved in many physiological and pathological conditions, including infections by bacteria, parasites, and viruses. As obligate intracellular pathogens, viruses use intracellular machineries and pathways for efficient replication in their host target cells. Interestingly, certain viruses, and, more especially, enveloped viruses belonging to different viral families and including human pathogens, can mediate cell-cell fusion between infected cells and neighboring non-infected cells. Depending of the cellular environment and tissue organization, this virus-mediated cell-cell fusion leads to the merge of membrane and cytoplasm contents and formation of multinucleated cells, also called syncytia, that can express high amount of viral antigens in tissues and organs of infected hosts. This ability of some viruses to trigger cell-cell fusion between infected cells as virus-donor cells and surrounding non-infected target cells is mainly related to virus-encoded fusion proteins, known as viral fusogens displaying high fusogenic properties, and expressed at the cell surface of the virus-donor cells. Virus-induced cell-cell fusion is then mediated by interactions of these viral fusion proteins with surface molecules or receptors involved in virus entry and expressed on neighboring non-infected cells. Thus, the goal of this review is to give an overview of the different animal virus families, with a more special focus on human pathogens, that can trigger cell-cell fusion.


Subject(s)
Cell Fusion , Cell Membrane/metabolism , Membrane Fusion , Viral Fusion Proteins/metabolism , Virus Internalization , Viruses/metabolism , Animals , Humans , Viruses/isolation & purification
7.
Infect Genet Evol ; 89: 104733, 2021 04.
Article in English | MEDLINE | ID: covidwho-1386288

ABSTRACT

OBJECTIVE: A recent study on the effects of SARS-CoV-2 infection on the host's transcriptome indicated the perturbation of several pathways associated with neurodegeneration, including but not limited to Parkinson's and Huntington's diseases. The purpose of this study was to determine overlapping pathways between iPD vs. Controls and those associated with SARS-CoV-2 infection. METHODS: Gene set enrichment analyses (GSEA) were performed on gene expression data from tissues donated by idiopathic Parkinson's disease patients (iPD). These included dorsal motor nucleus of the vagus (DMNV), substantia nigra (SN), whole blood (WB) and peripheral blood mononuclear cell samples (PBMC). Enriched pathways detected by GSEA results were subsequently compared to (a) those retrieved by two independently constructed SARS-CoV-2 - host interactomes, as well as (b) previously published pathway data. For all analyses, a false discovery rate (FDR) <0.05 was considered statistically significant. RESULTS: Analysis of iPD data revealed multiple immune response and viral parasitism -related pathways (FDR < 0.05). Head-to-head comparisons as well as confirmatory analyses revealed several pathways and gene ontology (GO) terms overlapping between iPD tissues and SARS-CoV-2 induced transcriptomic changes: "Parkinson's Disease" and "Huntington's Disease" (overlapping in DMNV, ION, SN, and WB; FDR < 0.05), "NAFLD" (overlapping in DMNV, SN, PBMC and WB; FDR < 0.05), mRNA surveillance and proteostasis pathways (All datasets; FDR < 0.5), among others. CONCLUSION: The overlap noted in this comparative transcriptomic study outlines the potential contribution of human coronaviruses in the pathogenesis of iPD. Furthermore, given SARS-CoV-2's neuroinvasive potential, closer scrutiny is warranted towards its contribution in the long-term development of neurodegenerative disease.


Subject(s)
COVID-19/virology , Parkinson Disease/virology , SARS-CoV-2/physiology , Transcriptome , Case-Control Studies , Gene Expression , Gene Ontology , Humans , Parkinson Disease/genetics
8.
Nat Microbiol ; 6(1): 11-18, 2021 01.
Article in English | MEDLINE | ID: covidwho-1387364

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic is having a catastrophic impact on human health1. Widespread community transmission has triggered stringent distancing measures with severe socio-economic consequences. Gaining control of the pandemic will depend on the interruption of transmission chains until vaccine-induced or naturally acquired protective herd immunity arises. However, approved antiviral treatments such as remdesivir and reconvalescent serum cannot be delivered orally2,3, making them poorly suitable for transmission control. We previously reported the development of an orally efficacious ribonucleoside analogue inhibitor of influenza viruses, MK-4482/EIDD-2801 (refs. 4,5), that was repurposed for use against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is currently in phase II/III clinical trials (NCT04405570 and NCT04405739). Here, we explored the efficacy of therapeutically administered MK-4482/EIDD-2801 to mitigate SARS-CoV-2 infection and block transmission in the ferret model, given that ferrets and related members of the weasel genus transmit the virus efficiently with minimal clinical signs6-9, which resembles the spread in the human young-adult population. We demonstrate high SARS-CoV-2 burden in nasal tissues and secretions, which coincided with efficient transmission through direct contact. Therapeutic treatment of infected animals with MK-4482/EIDD-2801 twice a day significantly reduced the SARS-CoV-2 load in the upper respiratory tract and completely suppressed spread to untreated contact animals. This study identified oral MK-4482/EIDD-2801 as a promising antiviral countermeasure to break SARS-CoV-2 community transmission chains.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/prevention & control , COVID-19/transmission , Cytidine/analogs & derivatives , Hydroxylamines/pharmacology , SARS-CoV-2/drug effects , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Alanine/analogs & derivatives , Alanine/pharmacology , Animals , COVID-19/immunology , Chlorocebus aethiops , Cytidine/pharmacology , Cytokines/immunology , Disease Models, Animal , Disease Transmission, Infectious/prevention & control , Female , Ferrets , Random Allocation , Vero Cells
9.
Nat Commun ; 12(1): 134, 2021 01 08.
Article in English | MEDLINE | ID: covidwho-1387323

ABSTRACT

Understanding the factors that contribute to efficient SARS-CoV-2 infection of human cells may provide insights on SARS-CoV-2 transmissibility and pathogenesis, and reveal targets of intervention. Here, we analyze host and viral determinants essential for efficient SARS-CoV-2 infection in both human lung epithelial cells and ex vivo human lung tissues. We identify heparan sulfate as an important attachment factor for SARS-CoV-2 infection. Next, we show that sialic acids present on ACE2 prevent efficient spike/ACE2-interaction. While SARS-CoV infection is substantially limited by the sialic acid-mediated restriction in both human lung epithelial cells and ex vivo human lung tissues, infection by SARS-CoV-2 is limited to a lesser extent. We further demonstrate that the furin-like cleavage site in SARS-CoV-2 spike is required for efficient virus replication in human lung but not intestinal tissues. These findings provide insights on the efficient SARS-CoV-2 infection of human lungs.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , COVID-19/transmission , Sialic Acids/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment , Animals , Caco-2 Cells , Cell Line, Tumor , Chlorocebus aethiops , Cricetinae , Furin/metabolism , HEK293 Cells , Heparitin Sulfate/metabolism , Humans , Intestinal Mucosa/metabolism , Intestines/virology , Lung/pathology , Lung/virology , SARS-CoV-2/physiology , Severe Acute Respiratory Syndrome/pathology , Vero Cells , Virus Internalization , Virus Replication/physiology
10.
Front Pharmacol ; 11: 579330, 2020.
Article in English | MEDLINE | ID: covidwho-1389228

ABSTRACT

The Syrian golden hamster (Mesocricetus auratus) has recently been demonstrated as a clinically relevant animal model for SARS-CoV-2 infection. However, lack of knowledge about the tissue-specific expression pattern of various proteins in these animals and the unavailability of reagents like antibodies against this species hampers these models' optimal use. The major objective of our current study was to analyze the tissue-specific expression pattern of angiotensin-converting enzyme 2, a proven functional receptor for SARS-CoV-2 in different organs of the hamster. Using two different antibodies (MA5-32307 and AF933), we have conducted immunoblotting, immunohistochemistry, and immunofluorescence analysis to evaluate the ACE2 expression in different tissues of the hamster. Further, at the mRNA level, the expression of Ace2 in tissues was evaluated through RT-qPCR analysis. Both the antibodies detected expression of ACE2 in kidney, small intestine, tongue, and liver. Epithelium of proximal tubules of kidney and surface epithelium of ileum expresses a very high amount of this protein. Surprisingly, analysis of stained tissue sections showed no detectable expression of ACE2 in the lung or tracheal epithelial cells. Similarly, all parts of the large intestine were negative for ACE2 expression. Analysis of tissues from different age groups and sex didn't show any obvious difference in ACE2 expression pattern or level. Together, our findings corroborate some of the earlier reports related to ACE2 expression patterns in human tissues and contradict others. We believe that this study's findings have provided evidence that demands further investigation to understand the predominant respiratory pathology of SARS-CoV-2 infection and disease.

11.
Front Mol Biosci ; 7: 568954, 2020.
Article in English | MEDLINE | ID: covidwho-1389212

ABSTRACT

Because ACE2 is a host cell receptor of the SARS-CoV-2, an investigation of ACE2 expression in normal and virus-infected human tissues is crucial for understanding the mechanism of SARS-CoV-2 infection. We identified pathways associated with ACE2 expression and gene co-expression networks of ACE2 in pan-tissue based on the gene expression profiles in normal human tissues. We found that the pathways significantly associated with ACE2 upregulation were mainly involved in immune, stromal signature, metabolism, cell growth and proliferation, and cancer and other diseases. The number of genes having a significant positive expression correlation with ACE2 in females far exceeded that in males. The estrogen receptors (ESR1 and ESR2) and androgen receptor (AR) genes had a significant positive expression correlation with ACE2. Meanwhile, the enrichment levels of immune cells were positively associated with the expression levels of ESR1 and ESR2, while they were inversely associated with the expression levels of AR in pan-tissue and multiple individual tissues. It suggests that females are likely to have a more robust immune defense system against SARS-CoV-2 than males. ACE2 was upregulated in SARS-CoV-2-infected tissues relative to normal tissues and in SARS-CoV-2-infected males relative to females, while its expression levels had no significant difference between healthy females and males. Numerous immune-related pathways were highly enriched in SARS-CoV-2-infected males relative to females. These data indicate that males are more susceptible and more likely to have an excessive immune response to SARS-CoV-2 infection than females. This study furnishes potentially cues explaining why females have better clinical outcomes of SARS-CoV-2 infections than males and warrant further investigation for understanding the mechanism of SARS-CoV-2 infection.

12.
Biochem Biophys Res Commun ; 565: 64-71, 2021 08 06.
Article in English | MEDLINE | ID: covidwho-1251023

ABSTRACT

Neutrophil extracellular traps (NETs) are extracellular webs of DNA, histones and granular contents that are released by neutrophils to control infections. However, NETs that is not properly regulated can propagate inflammation and thrombosis. It was recognized that viruses can induce NETs. As a synthetic analog of viral double-stranded (ds) RNA, polyinosinic-polycytidylic acid [poly(I:C)] is known to induce inflammation and thrombosis. However, whether and how poly(I:C) modulates NETs remains unclear. Here, we have demonstrated that poly(I:C) induced extracellular DNA traps in human neutrophils in a dose-dependent manner. Further, poly(I:C) or dsRNA virus elevated the levels of myeloperoxidase-DNA complexes and citrullinated histone H3, which are specific markers of NETs, in both neutrophil supernatants and mouse plasma. Interestingly, a potent peptidylarginine deiminase 4 (PAD4) inhibitor, BB-CL-Amidine (BB-CLA) or PAD4 knockdown effectively prevented poly(I:C)-induced NETs formation and release. In addition, BB-CLA abrogated poly(I:C)-triggered neutrophil activation and infiltration, and vascular permeability in lungs. BB-CLA also attenuated poly(I:C)-induced thrombocytopenia in circulation, fibrin deposition and thrombus formation in tissues. Taken together, these results suggest that viral mimetic poly(I:C) may induce NETs-dependent inflammation and thrombosis through PAD4, and that inhibiting PAD4 may become a good strategy to protect against viral infection-caused inflammation/thrombosis-related pathological conditions of diseases.


Subject(s)
Extracellular Traps/drug effects , Inflammation/metabolism , Neutrophils/drug effects , Poly I-C/pharmacology , Protein-Arginine Deiminase Type 4/metabolism , Thrombosis/metabolism , Amidines/pharmacology , Animals , Cells, Cultured , Chlorocebus aethiops , Humans , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Neutrophil Activation/drug effects , Neutrophils/metabolism , Protein-Arginine Deiminase Type 4/antagonists & inhibitors , Thrombosis/pathology
13.
Nat Med ; 27(3): 546-559, 2021 03.
Article in English | MEDLINE | ID: covidwho-1319033

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2+TMPRSS2+ cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.


Subject(s)
COVID-19/epidemiology , COVID-19/genetics , Host-Pathogen Interactions/genetics , SARS-CoV-2/physiology , Sequence Analysis, RNA/statistics & numerical data , Single-Cell Analysis/statistics & numerical data , Virus Internalization , Adult , Aged , Aged, 80 and over , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/virology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/pathology , COVID-19/virology , Cathepsin L/genetics , Cathepsin L/metabolism , Datasets as Topic/statistics & numerical data , Demography , Female , Gene Expression Profiling/statistics & numerical data , Humans , Lung/metabolism , Lung/virology , Male , Middle Aged , Organ Specificity/genetics , Respiratory System/metabolism , Respiratory System/virology , Sequence Analysis, RNA/methods , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Single-Cell Analysis/methods
14.
Clin Infect Dis ; 73(2): e503-e512, 2021 07 15.
Article in English | MEDLINE | ID: covidwho-1315661

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is primarily an acute respiratory tract infection. Distinctively, a substantial proportion of COVID-19 patients develop olfactory dysfunction. Especially in young patients, loss of smell can be the first or only symptom. The roles of inflammatory obstruction of the olfactory clefts, inflammatory cytokines affecting olfactory neuronal function, destruction of olfactory neurons or their supporting cells, and direct invasion of olfactory bulbs in causing olfactory dysfunction are uncertain. METHODS: We investigated the location for the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from the olfactory epithelium (OE) to the olfactory bulb in golden Syrian hamsters. RESULTS: After intranasal inoculation with SARS-CoV-2, inflammatory cell infiltration and proinflammatory cytokine/chemokine responses were detected in the nasal turbinate tissues. The responses peaked between 2 and 4 days postinfection, with the highest viral load detected at day 2 postinfection. In addition to the pseudo-columnar ciliated respiratory epithelial cells, SARS-CoV-2 viral antigens were also detected in the mature olfactory sensory neurons labeled by olfactory marker protein, in the less mature olfactory neurons labeled by neuron-specific class III ß-tubulin at the more basal position, and in the sustentacular cells, resulting in apoptosis and severe destruction of the OE. During the entire course of infection, SARS-CoV-2 viral antigens were not detected in the olfactory bulb. CONCLUSIONS: In addition to acute inflammation at the OE, infection of mature and immature olfactory neurons and the supporting sustentacular cells by SARS-CoV-2 may contribute to the unique olfactory dysfunction related to COVID-19, which is not reported with SARS-CoV-2.


Subject(s)
COVID-19 , Olfactory Receptor Neurons , Animals , Cricetinae , Humans , Mesocricetus , Olfactory Mucosa , SARS-CoV-2
15.
Int J Mol Sci ; 21(20)2020 Oct 09.
Article in English | MEDLINE | ID: covidwho-1298152

ABSTRACT

Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels responsible for rapid neural and neuromuscular signal transmission. Although it is well documented that 16 subunits are encoded by the human genome, their presence in airway epithelial cells (AECs) remains poorly understood, and contribution to pathology is mainly discussed in the context of cancer. We analysed nAChR subunit expression in the human lungs of smokers and non-smokers using transcriptomic data for whole-lung tissues, isolated large AECs, and isolated small AECs. We identified differential expressions of nAChRs in terms of detection and repartition in the three modalities. Smoking-associated alterations were also unveiled. Then, we identified an nAChR transcriptomic print at the single-cell level. Finally, we reported the localizations of detectable nAChRs in bronchi and large bronchioles. Thus, we compiled the first complete atlas of pulmonary nAChR subunits to open new avenues to further unravel the involvement of these receptors in lung homeostasis and respiratory diseases.


Subject(s)
Lung/metabolism , Protein Subunits/metabolism , Receptors, Nicotinic/metabolism , Adult , Age Factors , Cell Cycle , Epithelial Cells/metabolism , Gene Expression Regulation , Humans , Protein Subunits/chemistry , Protein Subunits/genetics , Receptors, Nicotinic/chemistry , Receptors, Nicotinic/genetics , Respiratory Mucosa/metabolism , Respiratory Mucosa/pathology , Signal Detection, Psychological , Smoking , Transcription, Genetic
16.
Methods Mol Biol ; 2099: 137-159, 2020.
Article in English | MEDLINE | ID: covidwho-1292550

ABSTRACT

Since 2012, monthly cases of Middle East respiratory syndrome coronavirus (MERS-CoV) continue to cause severe respiratory disease that is fatal in ~35% of diagnosed individuals. The ongoing threat to global public health and the need for novel therapeutic countermeasures have driven the development of animal models that can reproducibly replicate the pathology associated with MERS-CoV in human infections. The inability of MERS-CoV to replicate in the respiratory tracts of mice, hamsters, and ferrets stymied initial attempts to generate small animal models. Identification of human dipeptidyl peptidase IV (hDPP4) as the receptor for MERS-CoV infection opened the door for genetic engineering of mice. Precise molecular engineering of mouse DPP4 (mDPP4) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology maintained inherent expression profiles, and limited MERS-CoV susceptibility to tissues that naturally express mDPP4, notably the lower respiratory tract wherein MERS-CoV elicits severe pulmonary pathology. Here, we describe the generation of the 288-330+/+ MERS-CoV mouse model in which mice were made susceptible to MERS-CoV by modifying two amino acids on mDPP4 (A288 and T330), and the use of adaptive evolution to generate novel MERS-CoV isolates that cause fatal respiratory disease. The 288-330+/+ mice are currently being used to evaluate novel drug, antibody, and vaccine therapeutic countermeasures for MERS-CoV. The chapter starts with a historical perspective on the emergence of MERS-CoV and animal models evaluated for MERS-CoV pathogenesis, and then outlines the development of the 288-330+/+ mouse model, assays for assessing a MERS-CoV pulmonary infection in a mouse model, and describes some of the challenges associated with using genetically engineered mice.


Subject(s)
Coronavirus Infections/virology , Dipeptidyl Peptidase 4/genetics , Disease Models, Animal , Mice/genetics , Middle East Respiratory Syndrome Coronavirus/physiology , Respiratory Distress Syndrome/virology , Animals , CRISPR-Cas Systems , Coronavirus Infections/pathology , Dipeptidyl Peptidase 4/metabolism , Disease Susceptibility , Female , Genetic Engineering , Humans , Lung/virology , Male , Mice, Inbred C57BL , Respiratory Distress Syndrome/pathology
17.
J Obstet Gynaecol Can ; 42(3): 301-303, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-1291550

ABSTRACT

Vulvovaginal atrophy (VVA) resulting from estrogen deprivation at menopause often results in distressing vaginal dryness and dyspareunia. Fewer than 25% of affected women seek help for this condition citing embarrassment, cultural values, an aging or unavailable partner and concerns about use of estrogens following the Women's Health Initiative. Available non-hormonal treatments, such as moisturizers, while affording some relief can be messy to apply and do not prevent disease progression. A new oral selective estrogen receptor modulator, ospemifene, has been found to have strong estrogenic activity in vaginal tissues without adverse estrogenic effects at other sites.


Subject(s)
Atrophy/drug therapy , Menopause , Selective Estrogen Receptor Modulators/administration & dosage , Tamoxifen/analogs & derivatives , Vagina/drug effects , Vulva/drug effects , Aged , Atrophy/pathology , COVID-19/drug therapy , Dyspareunia/drug therapy , Female , Humans , Menopause/physiology , Middle Aged , Postmenopause , Selective Estrogen Receptor Modulators/therapeutic use , Tamoxifen/administration & dosage , Tamoxifen/therapeutic use , Vagina/pathology , Vulva/pathology
18.
Acta Pharmacol Sin ; 41(12): 1539-1546, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-1269381

ABSTRACT

The pandemic of coronavirus disease 2019 (COVID-19) and its pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have become the greatest current threat to global public health. The highly infectious SARS-CoV-2 virus primarily attacks pulmonary tissues and impairs gas exchange leading to acute respiratory distress syndrome (ARDS) and systemic hypoxia. The current pharmacotherapies for COVID-19 largely rely on supportive and anti-thrombi treatment and the repurposing of antimalarial and antiviral drugs such as hydroxychloroquine and remdesivir. For a better mechanistic understanding of COVID-19, our present review focuses on its primary pathophysiologic features: hypoxia and cytokine storm, which are a prelude to multiple organ failure and lethality. We discussed a possible link between the activation of hypoxia inducible factor 1α (HIF-1α) and cell entry of SARS-CoV-2, since HIF-1α is shown to suppress the angiotensin-converting enzyme 2 (ACE2) receptor and transmembrane protease serine 2 (TMPRSS2) and upregulate disintegrin and metalloproteinase domain-containing protein 17 (ADAM17). In addition, the protein targets of HIF-1α are involved with the activation of pro-inflammatory cytokine expression and the subsequent inflammatory process. Furthermore, we hypothesized a potential utility of so-called "hypoxic conditioning" to activate HIF-1α-induced cytoprotective signaling for reduction of illness severity and improvement of vital organ function in patients with COVID-19. Taken together, we would propose further investigations into the hypoxia-related molecular mechanisms, from which novel targeted therapies can be developed for the improved management of COVID-19.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Animals , COVID-19/physiopathology , COVID-19/virology , Cytokine Release Syndrome/virology , Drug Development , Drug Repositioning , Humans , Hypoxia/drug therapy , Hypoxia/virology , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Molecular Targeted Therapy , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity
19.
Cell Biosci ; 11(1): 110, 2021 Jun 13.
Article in English | MEDLINE | ID: covidwho-1268191

ABSTRACT

The COVID-19 pandemic is having a tremendous impact on humanity. Although COVID-19 vaccines are showing promising results, they are not 100% effective and resistant mutant SARS-CoV-2 strains are on the rise. To successfully fight against SARS-CoV-2 and prepare for future coronavirus outbreaks, it is essential to understand SARS-CoV-2 protein functions, their host interactions, and how these processes convey pathogenicity at host tissue, organ and systemic levels. In vitro models are valuable but lack the physiological context of a whole organism. Current animal models for SARS-CoV-2 research are exclusively mammals, with the intrinsic limitations of long reproduction times, few progeny, ethical concerns and high maintenance costs. These limitations make them unsuitable for rapid functional investigations of virus proteins as well as genetic and pharmacological screens. Remarkably, 90% of the SARS-CoV-2 virus-host interacting proteins are conserved between Drosophila and humans. As a well-established model system for studying human diseases, the fruit fly offers a highly complementary alternative to current mammalian models for SARS-CoV-2 research, from investigating virus protein function to developing targeted drugs. Herein, we review Drosophila's track record in studying human viruses and discuss the advantages and limitations of using fruit flies for SARS-CoV-2 research. We also review studies that already used Drosophila to investigate SARS-CoV-2 protein pathogenicity and their damaging effects in COVID-19 relevant tissues, as well as studies in which the fly was used as an efficient whole animal drug testing platform for targeted therapeutics against SARS-CoV-2 proteins or their host interacting pathways.

20.
Br J Haematol ; 194(3): 518-529, 2021 08.
Article in English | MEDLINE | ID: covidwho-1266318

ABSTRACT

The COVID-19 pandemic has been the most significant health crisis in recent global history. Early studies from Wuhan highlighted COVID-19-associated coagulopathy and a significant association with mortality was soon recognised. As research continues across the world, more evidence is emerging of the cross-talk between the innate immune system, coagulation activation and inflammation. Immunothrombosis has been demonstrated to play a key role in the pathophysiology of severe COVID-19, with extracellular histones and neutrophil extracellular traps detected in the plasma and cardiopulmonary tissues of critically ill patients. Targeting the components of immunothrombosis is becoming an important factor in the treatment of patients with COVID-19 infection. Recent studies report outcomes of intermediate and therapeutic anticoagulation in hospitalised patients with varying severities of COVID-19 disease, including optimal dosing and associated bleeding risks. Immunomodulatory therapies, including corticosteroids and IL-6 receptor antagonists, have been demonstrated to significantly reduce mortality in COVID-19 patients. As the pandemic continues, more studies are required to understand the driving factors and upstream mechanisms for coagulopathy and immunothrombosis in COVID-19, and thus potentially develop more targeted therapies for SARS-CoV-2 infection, both in the acute phase and in those who develop longer-term symptom burden.


Subject(s)
COVID-19/complications , Thrombosis/etiology , Animals , Blood Coagulation , COVID-19/blood , COVID-19/immunology , COVID-19/therapy , Disease Management , Humans , Immunogenic Cell Death , Inflammation/blood , Inflammation/etiology , Inflammation/immunology , Inflammation/therapy , SARS-CoV-2/immunology , Thrombosis/blood , Thrombosis/immunology , Thrombosis/therapy
SELECTION OF CITATIONS
SEARCH DETAIL