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1.
Int J Mol Sci ; 23(3)2022 Jan 19.
Article in English | MEDLINE | ID: covidwho-1625612

ABSTRACT

Repurposing of the anthelminthic drug niclosamide was proposed as an effective treatment for inflammatory airway diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease. Niclosamide may also be effective for the treatment of viral respiratory infections, such as SARS-CoV-2, respiratory syncytial virus, and influenza. While systemic application of niclosamide may lead to unwanted side effects, local administration via aerosol may circumvent these problems, particularly when the drug is encapsulated into small polyethylene glycol (PEG) hydrospheres. In the present study, we examined whether PEG-encapsulated niclosamide inhibits the production of mucus and affects the pro-inflammatory mediator CLCA1 in mouse airways in vivo, while effects on mucociliary clearance were assessed in excised mouse tracheas. The potential of encapsulated niclosamide to inhibit TMEM16A whole-cell Cl- currents and intracellular Ca2+ signalling was assessed in airway epithelial cells in vitro. We achieved encapsulation of niclosamide in PEG-microspheres and PEG-nanospheres (Niclo-spheres). When applied to asthmatic mice via intratracheal instillation, Niclo-spheres strongly attenuated overproduction of mucus, inhibited secretion of the major proinflammatory mediator CLCA1, and improved mucociliary clearance in tracheas ex vivo. These effects were comparable for niclosamide encapsulated in PEG-nanospheres and PEG-microspheres. Niclo-spheres inhibited the Ca2+ activated Cl- channel TMEM16A and attenuated mucus production in CFBE and Calu-3 human airway epithelial cells. Both inhibitory effects were explained by a pronounced inhibition of intracellular Ca2+ signals. The data indicate that poorly dissolvable compounds such as niclosamide can be encapsulated in PEG-microspheres/nanospheres and deposited locally on the airway epithelium as encapsulated drugs, which may be advantageous over systemic application.


Subject(s)
Niclosamide/administration & dosage , Pneumonia/drug therapy , Respiratory System/drug effects , Animals , Asthma/drug therapy , Asthma/metabolism , Asthma/pathology , COVID-19/complications , COVID-19/drug therapy , Cells, Cultured , Disease Models, Animal , Drug Carriers/chemistry , Drug Compounding , Humans , Hydrogels/chemistry , Instillation, Drug , Mice , Microspheres , Mucus/drug effects , Mucus/metabolism , Nanospheres/administration & dosage , Nanospheres/chemistry , Niclosamide/chemistry , Niclosamide/pharmacokinetics , Pneumonia/pathology , Polyethylene Glycols/chemistry , Respiratory Mucosa/drug effects , Respiratory Mucosa/metabolism , Respiratory System/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Trachea
2.
Tissue Cell ; 74: 101679, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1521561

ABSTRACT

BACKGROUND: It is known that SARS-CoV-2 mostly infects the respiratory system causing pneumonia; although it can also affect the gastrointestinal tract (GIT), which covered with a bi-layer of mucus rich in glycosylated proteins that terminated by sialic acid. Therefore; this study aimed to evaluate serum total sialic acid (TSA) in moderate COVID-19 patients with and without GIT manifestations. METHODS: A total of 161 moderate COVID-19 patients without and with GIT manifestations and 50 controls were enrolled into our study. Serum electrolytes levels were measured by using colorimetric or turbidmetric commercial assay kits, while the level of serum TSA was measured by using a commercial ELISA kit. RESULTS: Our results showed that serum TSA level was highly significantly increased in moderate COVID-19 patients with GIT manifestations (81.43 ± 8.91) when compared with controls (61.24 ± 6.41) or even moderate COVID-19 patients without GIT manifestations (69.46 ± 7.03). ROC curve analysis showed that AUC for TSA is 0.84 with 76.2 % sensitivity and 73.7 % specificity in discrimination between moderate COVID-19 patients with and without GIT manifestations. Serum potassium and sodium levels were highly significantly decreased in moderate COVID-19 patients with GIT manifestations when compared with controls or even moderate COVID-19 patients without GIT manifestations; while serum calcium level was found to be significantly decreased in moderate COVID-19 patients with GIT manifestations when compared with controls. CONCLUSION: Finally, we can conclude that SA plays a crucial role in the pathogenesis of GIT complications associated with COVID-19 and could be a potential biomarker for the COVID-19 gastrointestinal complications.


Subject(s)
COVID-19/pathology , Gastrointestinal Tract/pathology , N-Acetylneuraminic Acid/blood , Adult , Biomarkers/blood , Enzyme-Linked Immunosorbent Assay , Female , Gastrointestinal Tract/virology , Humans , Male , Middle Aged , Mucus/metabolism , Mucus/virology , SARS-CoV-2
3.
Int J Mol Sci ; 22(21)2021 Oct 21.
Article in English | MEDLINE | ID: covidwho-1480797

ABSTRACT

The intestinal barrier plays an extremely important role in maintaining the immune homeostasis of the gut and the entire body. It is made up of an intricate system of cells, mucus and intestinal microbiota. A complex system of proteins allows the selective permeability of elements that are safe and necessary for the proper nutrition of the body. Disturbances in the tightness of this barrier result in the penetration of toxins and other harmful antigens into the system. Such events lead to various digestive tract dysfunctions, systemic infections, food intolerances and autoimmune diseases. Pathogenic and probiotic bacteria, and the compounds they secrete, undoubtedly affect the properties of the intestinal barrier. The discovery of zonulin, a protein with tight junction regulatory activity in the epithelia, sheds new light on the understanding of the role of the gut barrier in promoting health, as well as the formation of diseases. Coincidentally, there is an increasing number of reports on treatment methods that target gut microbiota, which suggests that the prevention of gut-barrier defects may be a viable approach for improving the condition of COVID-19 patients. Various bacteria-intestinal barrier interactions are the subject of this review, aiming to show the current state of knowledge on this topic and its potential therapeutic applications.


Subject(s)
Bacterial Infections/therapy , Haptoglobins/metabolism , Intestinal Mucosa/metabolism , Probiotics/therapeutic use , Protein Precursors/metabolism , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Bacterial Infections/pathology , Bacterial Physiological Phenomena , Gastrointestinal Microbiome , Humans , Intestinal Mucosa/microbiology , Mucus/metabolism , Tight Junctions/metabolism
4.
Front Immunol ; 12: 701443, 2021.
Article in English | MEDLINE | ID: covidwho-1470757

ABSTRACT

The airway mucus barrier is a primary defensive layer at the airway surface. Mucins are the major structural components of airway mucus that protect the respiratory tract. Respiratory viruses invade human airways and often induce abnormal mucin overproduction and airway mucus secretion, leading to airway obstruction and disease. The mechanism underlying the virus-induced abnormal airway mucus secretion has not been fully studied so far. Understanding the mechanisms by which viruses induce airway mucus hypersecretion may open new avenues to treatment. In this article, we elaborate the clinical and experimental evidence that respiratory viruses cause abnormal airway mucus secretion, review the underlying mechanisms, and also discuss the current research advance as well as potential strategies to treat the abnormal airway mucus secretion caused by SARS-CoV-2.


Subject(s)
Mucus/metabolism , Virus Diseases/metabolism , Animals , Humans , Respiratory System/metabolism
5.
J Ethnopharmacol ; 282: 114574, 2022 Jan 10.
Article in English | MEDLINE | ID: covidwho-1373117

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Gekko gecko is used as a traditional medicine for various diseases including respiratory disorders in northeast Asian countries, mainly Korea, Japan, and China. AIM OF THE STUDY: Allergic asthma is a chronic respiratory disease caused by an inappropriate immune response. Due to the recent spread of coronavirus disease 2019, interest in the treatment of pulmonary disorders has rapidly increased. In this study, we investigated the anti-asthmatic effects of G. gecko extract (GGE) using an established mouse model of ovalbumin-induced asthma. MATERIALS AND METHODS: To evaluate the anti-asthmatic effects of GGE, we evaluated histological changes and the responses of inflammatory mediators related to allergic airway inflammation. Furthermore, we investigated the regulatory effects of GGE on type 2 helper T (Th2) cell activation. RESULTS: Administration of GGE attenuated asthmatic phenotypes, including inflammatory cell infiltration, mucus production, and expression of Th2 cytokines. Furthermore, GGE treatment reduced Th2 cell activation and differentiation. CONCLUSIONS: These results indicate that GGE alleviates allergic airway inflammation by regulating Th2 cell activation and differentiation.


Subject(s)
Anti-Asthmatic Agents/therapeutic use , Asthma/drug therapy , Medicine, East Asian Traditional , Mucus/metabolism , Ovalbumin , Plant Extracts/therapeutic use , Animals , Asthma/chemically induced , Asthma/pathology , Bronchoalveolar Lavage Fluid , COVID-19 , Cytokines/metabolism , Female , Flow Cytometry , Immunoglobulin E/immunology , Inflammation Mediators/metabolism , Lung/pathology , Mice , Mice, Inbred BALB C , Pandemics , Th2 Cells/drug effects , Th2 Cells/immunology , Tryptamines/pharmacology
6.
Dev Cell ; 56(11): 1646-1660.e5, 2021 06 07.
Article in English | MEDLINE | ID: covidwho-1233404

ABSTRACT

Mucus-secreting goblet cells are the dominant cell type in pulmonary diseases, e.g., asthma and cystic fibrosis (CF), leading to pathologic mucus metaplasia and airway obstruction. Cytokines including IL-13 are the major players in the transdifferentiation of club cells into goblet cells. Unexpectedly, we have uncovered a previously undescribed pathway promoting mucous metaplasia that involves VEGFa and its receptor KDR. Single-cell RNA sequencing analysis coupled with genetic mouse modeling demonstrates that loss of epithelial VEGFa, KDR, or MEK/ERK kinase promotes excessive club-to-goblet transdifferentiation during development and regeneration. Sox9 is required for goblet cell differentiation following Kdr inhibition in both mouse and human club cells. Significantly, airway mucous metaplasia in asthmatic and CF patients is also associated with reduced KDR signaling and increased SOX9 expression. Together, these findings reveal an unexpected role for VEGFa/KDR signaling in the defense against mucous metaplasia, offering a potential therapeutic target for this common airway pathology.


Subject(s)
Airway Obstruction/genetics , Metaplasia/genetics , SOX9 Transcription Factor/genetics , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics , Airway Obstruction/metabolism , Airway Obstruction/pathology , Animals , Cell Transdifferentiation/genetics , Disease Models, Animal , Gene Expression Regulation/genetics , Goblet Cells/metabolism , Goblet Cells/pathology , Humans , Interleukin-13/genetics , MAP Kinase Signaling System/genetics , Metaplasia/pathology , Mice , Mucus/metabolism , Single-Cell Analysis
7.
Trends Microbiol ; 29(11): 983-992, 2021 11.
Article in English | MEDLINE | ID: covidwho-1187873

ABSTRACT

Efficient penetration of the mucus layer is needed for respiratory viruses to avoid mucociliary clearance prior to infection. Many respiratory viruses bind to glycans on the heavily glycosylated mucins that give mucus its gel-like characteristics. Influenza viruses, some paramyxoviruses, and coronaviruses avoid becoming trapped in the mucus by releasing themselves by means of their envelope-embedded enzymes that destroy glycan receptors. For efficient infection, receptor binding and destruction need to be in balance with the host receptor repertoire. Establishment in a novel host species requires resetting of the balance to adapt to the different glycan repertoire encountered. Growing understanding of species-specific mucosal glycosylation patterns and the dynamic interaction with respiratory viruses identifies the mucus layer as a major host-range determinant and barrier for zoonotic transfer.


Subject(s)
Host Specificity , Viruses , Glycosylation , Mucins/metabolism , Mucus/metabolism , Polysaccharides/metabolism , Viruses/metabolism
8.
Med Sci Monit ; 27: e928837, 2021 Feb 13.
Article in English | MEDLINE | ID: covidwho-1161104

ABSTRACT

BACKGROUND Coronavirus 2 (SARS-CoV-2) was declared a pandemic by the World Health Organization (WHO) in March 2020. To further reveal the pathologic associations between coronavirus and hypoxemia, we report the findings of 4 complete systematic autopsies of severe acute respiratory syndrome coronavirus 2-positive individuals who died of multiple organ failure caused by severe hypoxemia. MATERIAL AND METHODS We examined the donated corpses of 4 deceased patients who had been diagnosed with severe acute respiratory syndrome coronavirus 2. A complete post-mortem examination was carried out on each corpse, and multiple organs were macroscopically examined. RESULTS The 4 corpses were 2 males and 2 females, with an average age of 69 years. Bilateral lungs showed various degrees of atrophy and consolidation, with diffusely tough and solid texture in the sections. A thromboembolism was found in the main pulmonary artery extending into the atrium in 1 corpse, and significant atherosclerotic plaques tagged in the inner wall of the aortic arch were found in 2 corpses. Two corpses were found to have slightly atrophied bilateral renal parenchyma. Atrophic changes in the spleen were found in 2 corpses. Notably, there were significantly expanded alveolar septa and prominent fibroblastic proliferation. CONCLUSIONS The laboratory data of these corpses showed a progressive decrease in blood oxygen saturation, followed by refractory and irreversible hypoxemia. Clinical and laboratory information and autopsy and histologic presentations of multiple organs showed insufficient air exchange due to abnormalities in the respiratory system, and reduced erythropoiesis in bone marrow may play a role.


Subject(s)
Autopsy , COVID-19/pathology , COVID-19/virology , Hypoxia/complications , Hypoxia/pathology , Pneumonia/pathology , Pneumonia/virology , SARS-CoV-2/physiology , Aged , Aged, 80 and over , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , COVID-19/complications , Cell Aggregation , Female , Humans , Lung/pathology , Macrophages/pathology , Male , Middle Aged , Mucus/metabolism , Myocardium/pathology , Necrosis , Pneumonia/complications , Thoracic Cavity/pathology
9.
Cell Res ; 30(12): 1078-1087, 2020 12.
Article in English | MEDLINE | ID: covidwho-912896

ABSTRACT

Silent hypoxia has emerged as a unique feature of coronavirus disease 2019 (COVID-19). In this study, we show that mucins are accumulated in the bronchoalveolar lavage fluid (BALF) of COVID-19 patients and are upregulated in the lungs of severe respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected mice and macaques. We find that induction of either interferon (IFN)-ß or IFN-γ upon SARS-CoV-2 infection results in activation of aryl hydrocarbon receptor (AhR) signaling through an IDO-Kyn-dependent pathway, leading to transcriptional upregulation of the expression of mucins, both the secreted and membrane-bound, in alveolar epithelial cells. Consequently, accumulated alveolar mucus affects the blood-gas barrier, thus inducing hypoxia and diminishing lung capacity, which can be reversed by blocking AhR activity. These findings potentially explain the silent hypoxia formation in COVID-19 patients, and suggest a possible intervention strategy by targeting the AhR pathway.


Subject(s)
Interferons/metabolism , Mucus/metabolism , Receptors, Aryl Hydrocarbon/metabolism , Animals , COVID-19/pathology , COVID-19/virology , Cell Line , Epithelial Cells/cytology , Epithelial Cells/metabolism , Epithelial Cells/virology , Humans , Hypoxia , Interferon-beta/pharmacology , Interferon-gamma/pharmacology , Lung/metabolism , Lung/pathology , Macaca , Mice , Mice, Inbred ICR , Mice, Transgenic , Mucins/metabolism , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , Signal Transduction , Up-Regulation/drug effects
10.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L603-L619, 2020 10 01.
Article in English | MEDLINE | ID: covidwho-817848

ABSTRACT

Respiratory cilia are the driving force of the mucociliary escalator, working in conjunction with secreted airway mucus to clear inhaled debris and pathogens from the conducting airways. Respiratory cilia are also one of the first contact points between host and inhaled pathogens. Impaired ciliary function is a common pathological feature in patients with chronic airway diseases, increasing susceptibility to respiratory infections. Common respiratory pathogens, including viruses, bacteria, and fungi, have been shown to target cilia and/or ciliated airway epithelial cells, resulting in a disruption of mucociliary clearance that may facilitate host infection. Despite being an integral component of airway innate immunity, the role of respiratory cilia and their clinical significance during airway infections are still poorly understood. This review examines the expression, structure, and function of respiratory cilia during pathogenic infection of the airways. This review also discusses specific known points of interaction of bacteria, fungi, and viruses with respiratory cilia function. The emerging biological functions of motile cilia relating to intracellular signaling and their potential immunoregulatory roles during infection will also be discussed.


Subject(s)
Bacteria/immunology , Cilia/metabolism , Fungi/immunology , Mucociliary Clearance/physiology , Viruses/immunology , Epithelial Cells/metabolism , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate/immunology , Mucus/metabolism , Respiratory System/immunology
11.
Med Hypotheses ; 143: 110066, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-625121

ABSTRACT

The COVID-19 pandemic has not spared any continent. The disease has affected more than 7,500,000 individuals globally and killed approximately 450,000 individuals. The disease is caused by a very small virus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is an enveloped single-stranded RNA virus with a spike-like structure on its envelope that can interact with the angiotensin-converting enzyme 2 (ACE2) receptor after cleavage. ACE2 receptors are present in the human lungs and other organs. SARS-CoV-2 is a new virus that belongs to the subgenus Sarbecovirus; viruses in this subgenus have spread widely in the previous years and caused outbreaks of severe acute respiratory syndromes.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Models, Immunological , Pneumonia, Viral/immunology , Ageusia/etiology , Angiotensin-Converting Enzyme 2 , Betacoronavirus/pathogenicity , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Expectorants/therapeutic use , Host Microbial Interactions/immunology , Humans , Hypersensitivity/immunology , Hypersensitivity/virology , Mucus/metabolism , Olfaction Disorders/etiology , Pandemics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/complications , Pneumonia, Viral/virology , Respiratory Mucosa/immunology , Respiratory Mucosa/metabolism , Respiratory Mucosa/virology , SARS-CoV-2 , SOXB1 Transcription Factors/metabolism
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