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American Journal of Respiratory Cell... Jun 2023
Topics: Humans; Idiopathic Pulmonary Fibrosis; Mucus; Fibrosis; H(+)-K(+)-Exchanging ATPase
PubMed: 36996473
DOI: 10.1165/rcmb.2023-0096ED -
Respiratory Care Sep 2007Effective clearance of inhaled particles requires mucus production and continuous mucus transport from the lower airways to the oropharynx. Mucus production takes place... (Review)
Review
Effective clearance of inhaled particles requires mucus production and continuous mucus transport from the lower airways to the oropharynx. Mucus production takes place mainly in the peripheral airways. Mucus transport is achieved by the action of the ciliated cells that cover the inner surface of the airways (mucociliary transport) and by expiratory airflow. The capacity for mucociliary transport is highest in the peripheral airways, whereas the capacity for airflow transport is highest in the central airways. In patients with airways disease, mucociliary transport may be impaired and airflow transport may become the most important mucus transport mechanism.
Topics: Bronchi; Cough; Exhalation; Humans; Inhalation Exposure; Mucociliary Clearance; Mucus; Respiratory Mucosa
PubMed: 17716383
DOI: No ID Found -
Macromolecular Bioscience Aug 2017The present review is aimed at elucidating relatively new aspects of mucoadhesion/mucus interaction and related phenomena that emerged from a Mucoadhesion workshop held... (Review)
Review
The present review is aimed at elucidating relatively new aspects of mucoadhesion/mucus interaction and related phenomena that emerged from a Mucoadhesion workshop held in Munster on 2-3 September 2015 as a satellite event of the ICCC 13th-EUCHIS 12th. After a brief outline of the new issues, the focus is on mucus description, purification, and mucus/mucin characterization, all steps that are pivotal to the understanding of mucus related phenomena and the choice of the correct mucosal model for in vitro and ex vivo experiments, alternative bio/mucomimetic materials are also presented. Then a selection of preparative techniques and testing methods are described (at molecular as well as micro and macroscale) that may support the pharmaceutical development of mucus interactive systems and assist formulators in the scale-up and industrialization steps. Recent applications of mucoadhesive systems (including medical devices) intended for different routes of administration (oral, gastrointestinal, vaginal, nasal, ocular, and intravesical) and for the treatment of difficult to treat pathologies or the alleviation of symptoms are described.
Topics: Animals; Biomedical Research; Biomimetic Materials; Humans; Mucins; Mucus
PubMed: 28378910
DOI: 10.1002/mabi.201600534 -
Journal of Innate Immunity 2019Animals are usually regarded as independent entities within their respective environments. However, within an organism, eukaryotes and prokaryotes interact dynamically... (Review)
Review
Animals are usually regarded as independent entities within their respective environments. However, within an organism, eukaryotes and prokaryotes interact dynamically to form the so-called metaorganism or holobiont, where each partner fulfils its versatile and crucial role. This review focuses on the interplay between microorganisms and multicellular eukaryotes in the context of host physiology, in particular aging and mucus-associated crosstalk. In addition to the interactions between bacteria and the host, we highlight the importance of viruses and nonmodel organisms. Moreover, we discuss current culturing and computational methodologies that allow a deeper understanding of underlying mechanisms controlling the physiology of metaorganisms.
Topics: Aging; Animals; Computational Biology; Health Status; Host Microbial Interactions; Humans; Microbiota; Models, Biological; Mucus; Symbiosis
PubMed: 30566939
DOI: 10.1159/000495115 -
Seminars in Immunopathology Jan 2024The lungs serve as the primary organ for respiration, facilitating the vital exchange of gases with the bloodstream. Given their perpetual exposure to external... (Review)
Review
The lungs serve as the primary organ for respiration, facilitating the vital exchange of gases with the bloodstream. Given their perpetual exposure to external particulates and pathogens, they possess intricate protective barriers. Cellular adhesion in the lungs is robustly maintained through tight junctions, adherens junctions, and desmosomes. Furthermore, the pulmonary system features a mucociliary clearance mechanism that synthesizes mucus and transports it to the outside. This mucus is enriched with chemical barriers like antimicrobial proteins and immunoglobulin A (IgA). Additionally, a complex immunological network comprising epithelial cells, neural cells, and immune cells plays a pivotal role in pulmonary defense. A comprehensive understanding of these protective systems offers valuable insights into potential pathologies and their therapeutic interventions.
Topics: Humans; Lung; Animals; Mucociliary Clearance; Respiratory Mucosa; Tight Junctions; Cell Adhesion; Mucus
PubMed: 38451292
DOI: 10.1007/s00281-024-01003-y -
Frontiers in Immunology 2021The 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... (Review)
Review
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.
Topics: Animals; Humans; Mucus; Respiratory System; Virus Diseases
PubMed: 34650550
DOI: 10.3389/fimmu.2021.701443 -
World Journal of Gastroenterology Aug 2022Little was known about mammalian colon mucus (CM) until the beginning of the 21 century. Since that time considerable progress has been made in basic research addressing... (Review)
Review
Little was known about mammalian colon mucus (CM) until the beginning of the 21 century. Since that time considerable progress has been made in basic research addressing CM structure and functions. Human CM is formed by two distinct layers composed of gel-forming glycosylated mucins that are permanently secreted by goblet cells of the colonic epithelium. The inner layer is dense and impenetrable for bacteria, whereas the loose outer layer provides a habitat for abundant commensal microbiota. Mucus barrier integrity is essential for preventing bacterial contact with the mucosal epithelium and maintaining homeostasis in the gut, but it can be impaired by a variety of factors, including CM-damaging switch of commensal bacteria to mucin glycan consumption due to dietary fiber deficiency. It is proven that impairments in CM structure and function can lead to colonic barrier deterioration that opens direct bacterial access to the epithelium. Bacteria-induced damage dysregulates epithelial proliferation and causes mucosal inflammatory responses that may expand to the loosened CM and eventually result in severe disorders, including colitis and neoplastic growth. Recently described formation of bacterial biofilms within the inner CM layer was shown to be associated with both inflammation and cancer. Although obvious gaps in our knowledge of human CM remain, its importance for the pathogenesis of major colorectal diseases, comprising inflammatory bowel disease and colorectal cancer, is already recognized. Continuing progress in CM exploration is likely to result in the development of a range of new useful clinical applications addressing colorectal disease diagnosis, prevention and therapy.
Topics: Animals; Colon; Colorectal Neoplasms; Dietary Fiber; Humans; Intestinal Mucosa; Mammals; Mucins; Mucus; Polysaccharides
PubMed: 36157924
DOI: 10.3748/wjg.v28.i32.4475 -
Journal of the Royal Society, Interface Jan 2019Hagfish slime is a unique predator defence material containing a network of long fibrous threads each ∼10 cm in length. Hagfish release the threads in a condensed...
Hagfish slime is a unique predator defence material containing a network of long fibrous threads each ∼10 cm in length. Hagfish release the threads in a condensed coiled state known as skeins (∼100 µm), which must unravel within a fraction of a second to thwart a predator attack. Here we consider the hypothesis that viscous hydrodynamics can be responsible for this rapid unravelling, as opposed to chemical reaction kinetics alone. Our main conclusion is that, under reasonable physiological conditions, unravelling due to viscous drag can occur within a few hundred milliseconds, and is accelerated if the skein is pinned at a surface such as the mouth of a predator. We model a single skein unspooling as the fibre peels away due to viscous drag. We capture essential features by considering simplified cases of physiologically relevant flows and one-dimensional scenarios where the fibre is aligned with streamlines in either uniform or uniaxial extensional flow. The peeling resistance is modelled with a power-law dependence on peeling velocity. A dimensionless ratio of viscous drag to peeling resistance appears in the dynamical equations and determines the unraveling time scale. Our modelling approach is general and can be refined with future experimental measurements of peel strength for skein unravelling. It provides key insights into the unravelling process, offers potential answers to lingering questions about slime formation from threads and mucous vesicles, and will aid the growing interest in engineering similar bioinspired material systems.
Topics: Animals; Hagfishes; Hydrodynamics; Models, Biological; Mucus; Predatory Behavior; Seawater; Swimming; Viscosity
PubMed: 30958163
DOI: 10.1098/rsif.2018.0710 -
Current Opinion in Structural Biology Apr 2023Contrary to first appearances, mucus structural biology is not an oxymoron. Though mucus hydrogels derive their characteristics largely from intrinsically disordered,... (Review)
Review
Contrary to first appearances, mucus structural biology is not an oxymoron. Though mucus hydrogels derive their characteristics largely from intrinsically disordered, heavily glycosylated polypeptide segments, the secreted mucin glycoproteins that constitute mucus undergo an orderly assembly process controlled by folded domains at their termini. Recent structural studies revealed how mucin complexes promote disulphide-mediated polymerization to produce the mucus gel scaffold. Additional protein-protein and protein-glycan interactions likely tune the mesoscale properties, stability, and activities of mucins. Evidence is emerging that even intrinsically disordered glycosylated segments have specific structural roles in the production and properties of mucus. Though soft-matter biophysical approaches to understanding mucus remain highly relevant, high-resolution structural studies of mucins and other mucus components are providing new perspectives on these vital, protective hydrogels.
Topics: Mucins; Mucus; Glycoproteins; Polysaccharides; Glycosylation
PubMed: 36753925
DOI: 10.1016/j.sbi.2022.102524 -
Cold Spring Harbor Perspectives in... Nov 2012Our purpose here is not to address specific issues of mucus pathology, but to illustrate how polymer networks theory and its remarkable predictive power can be applied... (Review)
Review
Our purpose here is not to address specific issues of mucus pathology, but to illustrate how polymer networks theory and its remarkable predictive power can be applied to study the supramolecular dynamics of mucus. Avoiding unnecessary mathematical formalization, in the light of available theory, we focus on the rather slow progress and the still large number of missing gaps in the complex topology and supramolecular dynamics of airway mucus. We start with the limited information on the polymer physics of respiratory mucins to then converge on the supramolecular organization and resulting physical properties of the mucus gel. In each section, we briefly discuss progress on the subject, the uncertainties associated with the established knowledge, and the many riddles that still remain.
Topics: Gels; Humans; Hydrophobic and Hydrophilic Interactions; Kinetics; Molecular Conformation; Mucins; Mucus; Phase Transition; Polymers; Respiratory System
PubMed: 23125200
DOI: 10.1101/cshperspect.a009597