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Vijaykumar K, Leung HM, Barrios A, Wade J, Hathorne HY, Nichols DP, Tearney GJ, Rowe SM, Solomon GM. Longitudinal improvements in clinical and functional outcomes following initiation of elexacaftor/tezacaftor/ivacaftor in patients with cystic fibrosis. Heliyon 2024; 10:e29188. [PMID: 38681615 PMCID: PMC11052906 DOI: 10.1016/j.heliyon.2024.e29188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 03/28/2024] [Accepted: 04/02/2024] [Indexed: 05/01/2024] Open
Abstract
Background Use of elexacaftor/tezacaftor/ivacaftor (ETI) for treatment of cystic fibrosis (CF) has resulted in unprecedented clinical improvements necessitating development of outcome measures for monitoring disease course. Intranasal micro-optical coherence tomography (μOCT) has previously helped detect and characterize mucociliary abnormalities in patients with CF. This study was done to determine if μOCT can define the effects of ETI on nasal mucociliary clearance and monitor changes conferred to understand mechanistic effects of CFTR modulators beyond CFTR activation. Methods 26 subjects, with at least 1 F508del mutation were recruited and followed at baseline (visit 1), +1 month (visit 2) and +6 months (visit 4) following initiation of ETI therapy. Clinical outcomes were computed at visits 1, 2 and 4. Intranasal μOCT imaging and functional metrics analysis including mucociliary transport rate (MCT) estimation were done at visits 1 and 2. Results Percent predicted forced expiratory volume in 1 s (ppFEV1) showed a significant increase of +10.9 % at visit 2, which sustained at visit 4 (+10.6 %). Sweat chloride levels significantly decreased by -36.6 mmol/L and -41.3 mmol/L at visits 2 and 4, respectively. μOCT analysis revealed significant improvement in MCT rate (2.8 ± 1.5, visit 1 vs 4.0 ± 1.5 mm/min, visit 2; P = 0.048). Conclusions Treatment with ETI resulted in significant and sustained clinical improvements over 6 months. Functional improvements in MCT rate were evident within a month after initiation of ETI therapy indicating that μOCT imaging is sensitive to the treatment effect of HEMT and suggests improved mucociliary transport as a probable mechanism of action underlying the clinical benefits.
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Affiliation(s)
- Kadambari Vijaykumar
- Department of Medicine, University of Alabama at Birmingham, AL, United States
- Gregory Fleming James CF Research Center, Birmingham, AL, United States
| | - Hui Min Leung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, United States
| | - Amilcar Barrios
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, United States
| | - Justin Wade
- Gregory Fleming James CF Research Center, Birmingham, AL, United States
| | | | | | - Guillermo J. Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, United States
| | - Steven M. Rowe
- Department of Medicine, University of Alabama at Birmingham, AL, United States
- Gregory Fleming James CF Research Center, Birmingham, AL, United States
| | - George M. Solomon
- Department of Medicine, University of Alabama at Birmingham, AL, United States
- Gregory Fleming James CF Research Center, Birmingham, AL, United States
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2
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Furtado KL, Plott L, Markovetz M, Powers D, Wang H, Hill DB, Papin J, Allbritton NL, Tamayo R. Clostridioides difficile-mucus interactions encompass shifts in gene expression, metabolism, and biofilm formation. bioRxiv 2024:2024.02.01.578425. [PMID: 38352512 PMCID: PMC10862863 DOI: 10.1101/2024.02.01.578425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, Clostridioides diffiicile, independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed C. difficile-mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes C. difficile growth both in vitro and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of C. difficile-mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation in vitro, which may in turn alter viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of C. difficile to human gastrointestinal mucus and highlight a flexibility in metabolism that may influence pathogenesis.
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Affiliation(s)
- Kathleen L. Furtado
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Lucas Plott
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Matthew Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Deborah Powers
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Hao Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - David B. Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Physics and Astronomy, College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason Papin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | | | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
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3
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Donoghue LJ, Markovetz MR, Morrison CB, Chen G, McFadden KM, Sadritabrizi T, Gutay MI, Kato T, Rogers TD, Snead JY, Livraghi-Butrico A, Button B, Ehre C, Grubb BR, Hill DB, Kelada SNP. BPIFB1 loss alters airway mucus properties and diminishes mucociliary clearance. Am J Physiol Lung Cell Mol Physiol 2023; 325:L765-L775. [PMID: 37847709 PMCID: PMC11068428 DOI: 10.1152/ajplung.00390.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 09/22/2023] [Accepted: 10/02/2023] [Indexed: 10/19/2023] Open
Abstract
Airway mucociliary clearance (MCC) is required for host defense and is often diminished in chronic lung diseases. Effective clearance depends upon coordinated actions of the airway epithelium and a mobile mucus layer. Dysregulation of the primary secreted airway mucin proteins, MUC5B and MUC5AC, is associated with a reduction in the rate of MCC; however, how other secreted proteins impact the integrity of the mucus layer and MCC remains unclear. We previously identified the gene Bpifb1/Lplunc1 as a regulator of airway MUC5B protein levels using genetic approaches. Here, we show that BPIFB1 is required for effective MCC in vivo using Bpifb1 knockout (KO) mice. Reduced MCC in Bpifb1 KO mice occurred in the absence of defects in epithelial ion transport or reduced ciliary beat frequency. Loss of BPIFB1 in vivo and in vitro altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC. Finally, we detected colocalization of BPIFB1 and MUC5B in secretory granules in mice and the protein mesh of secreted mucus in human airway epithelia cultures. Collectively, our findings demonstrate that BPIFB1 is an important component of the mucociliary apparatus in mice and a key component of the mucus protein network.NEW & NOTEWORTHY BPIFB1, also known as LPLUNC1, was found to regulate mucociliary clearance (MCC), a key aspect of host defense in the airway. Loss of this protein was also associated with altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC.
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Affiliation(s)
- Lauren J Donoghue
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Cameron B Morrison
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Gang Chen
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Kathryn M McFadden
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Taraneh Sadritabrizi
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Mark I Gutay
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Takafumi Kato
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Troy D Rogers
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Jazmin Y Snead
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Alessandra Livraghi-Butrico
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Division of Pediatric Pulmonology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Barbara R Grubb
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Samir N P Kelada
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
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4
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Vasquez PA, Walker B, Bloom K, Kolbin D, Caughman N, Freeman R, Lysy M, Hult C, Newhall KA, Papanikolas M, Edelmaier C, Forest MG. The power of weak, transient interactions across biology: A paradigm of emergent behavior. Physica D 2023; 454:133866. [PMID: 38274029 PMCID: PMC10806540 DOI: 10.1016/j.physd.2023.133866] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
A growing list of diverse biological systems and their equally diverse functionalities provides realizations of a paradigm of emergent behavior. In each of these biological systems, pervasive ensembles of weak, short-lived, spatially local interactions act autonomously to convey functionalities at larger spatial and temporal scales. In this article, a range of diverse systems and functionalities are presented in a cursory manner with literature citations for further details. Then two systems and their properties are discussed in more detail: yeast chromosome biology and human respiratory mucus.
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Affiliation(s)
- Paula A. Vasquez
- Department of Mathematics, University of South Carolina, United States of America
| | - Ben Walker
- Department of Mathematics, University of California at Irvine, United States of America
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, United States of America
| | - Daniel Kolbin
- Department of Biology, University of North Carolina at Chapel Hill, United States of America
| | - Neall Caughman
- Department of Mathematics, University of North Carolina at Chapel Hill, United States of America
| | - Ronit Freeman
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, United States of America
| | - Martin Lysy
- Department of Statistics and Actuarial Science, University of Waterloo, Canada
| | - Caitlin Hult
- Department of Mathematics, Gettysburg College, United States of America
| | - Katherine A. Newhall
- Department of Mathematics, University of North Carolina at Chapel Hill, United States of America
| | - Micah Papanikolas
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, United States of America
| | - Christopher Edelmaier
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, United States of America
- Center for Computational Biology, Flatiron Institute, United States of America
| | - M. Gregory Forest
- Department of Mathematics, University of North Carolina at Chapel Hill, United States of America
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, United States of America
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5
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Ling KM, Stick SM, Kicic A. Pulmonary bacteriophage and cystic fibrosis airway mucus: friends or foes? Front Med (Lausanne) 2023; 10:1088494. [PMID: 37265479 PMCID: PMC10230084 DOI: 10.3389/fmed.2023.1088494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/11/2023] [Indexed: 06/03/2023] Open
Abstract
For those born with cystic fibrosis (CF), hyper-concentrated mucus with a dysfunctional structure significantly impacts CF airways, providing a perfect environment for bacterial colonization and subsequent chronic infection. Early treatment with antibiotics limits the prevalence of bacterial pathogens but permanently alters the CF airway microenvironment, resulting in antibiotic resistance and other long-term consequences. With little investment into new traditional antibiotics, safe and effective alternative therapeutic options are urgently needed. One gathering significant traction is bacteriophage (phage) therapy. However, little is known about which phages are effective for respiratory infections, the dynamics involved between phage(s) and the host airway, and associated by-products, including mucus. Work utilizing gut cell models suggest that phages adhere to mucus components, reducing microbial colonization and providing non-host-derived immune protection. Thus, phages retained in the CF mucus layer result from the positive selection that enables them to remain in the mucus layer. Phages bind weakly to mucus components, slowing down the diffusion motion and increasing their chance of encountering bacterial species for subsequent infection. Adherence of phage to mucus could also facilitate phage enrichment and persistence within the microenvironment, resulting in a potent phage phenotype or vice versa. However, how the CF microenvironment responds to phage and impacts phage functionality remains unknown. This review discusses CF associated lung diseases, the impact of CF mucus, and chronic bacterial infection. It then discusses the therapeutic potential of phages, their dynamic relationship with mucus and whether this may enhance or hinder airway bacterial infections in CF.
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Affiliation(s)
- Kak-Ming Ling
- Wal-Yan Respiratory Research Centre, Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA, Australia
| | - Stephen Michael Stick
- Wal-Yan Respiratory Research Centre, Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
- Division of Paediatrics, Medical School, The University of Western Australia, Perth, WA, Australia
- Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, WA, Australia
| | - Anthony Kicic
- Wal-Yan Respiratory Research Centre, Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA, Australia
- Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, WA, Australia
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6
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Markovetz MR, Hibbard JE, Plott LM, Bacudio LG, Kissner WJ, Ghio A, Kumar PA, Arora H, Hill DB. Normalizing salt content by mixing native human airway mucus samples normalizes sample rheology. Front Physiol 2023; 14:1111647. [PMID: 36969580 PMCID: PMC10036356 DOI: 10.3389/fphys.2023.1111647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Across the globe, millions of people are affected by muco-obstructive pulmonary diseases like cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In MOPDs, the airway mucus becomes hyperconcentrated, increasing viscoelasticity and impairing mucus clearance. Research focused on treatment of MOPDs requires relevant sources of airway mucus both as a control sample type and as a basis for manipulation to study the effects of additional hyperconcentration, inflammatory milieu, and biofilm growth on the biochemical and biophysical properties of mucus. Endotracheal tube mucus has been identified as a prospective source of native airway mucus given its several advantages over sputum and airway cell culture mucus such as ease of access and in vivo production that includes surface airway and submucosal gland secretions. Still, many ETT samples suffer from altered tonicity and composition from either dehydration, salivary dilution, or other contamination. Herein, the biochemical compositions of ETT mucus from healthy human subjects were determined. Samples were characterized in terms of tonicity, pooled, and restored to normal tonicity. Salt-normalized ETT mucus exhibited similar concentration-dependent rheologic properties as originally isotonic mucus. This rheology agreed across spatial scales and with previous reports of the biophysics of ETT mucus. This work affirms previous reports of the importance of salt concentration on mucus rheology and presents methodology to increase yield native airway mucus samples for laboratory use and manipulation.
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Affiliation(s)
- Matthew R. Markovetz
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jacob E. Hibbard
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lucas M. Plott
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lawrence G. Bacudio
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - William J. Kissner
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Andrew Ghio
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Chapel Hill, NC, United States
| | - Priya A. Kumar
- Department of Anesthesiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Outcomes Research Consortium, Cleveland, OH, United States
| | - Harendra Arora
- Department of Anesthesiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Outcomes Research Consortium, Cleveland, OH, United States
| | - David B. Hill
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- *Correspondence: David B. Hill,
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7
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Rouillard KR, Markovetz MR, Kissner WJ, Boone WL, Plott LM, Hill DB. Altering the viscoelastic properties of mucus-grown Pseudomonas aeruginosa biofilms affects antibiotic susceptibility. Biofilm 2023; 5:100104. [PMID: 36711323 PMCID: PMC9880403 DOI: 10.1016/j.bioflm.2023.100104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023] Open
Abstract
The viscoelastic properties of biofilms are correlated with their susceptibility to mechanical and chemical stress, and the airway environment in muco-obstructive pulmonary diseases (MOPD) facilitates robust biofilm formation. Hyperconcentrated, viscoelastic mucus promotes chronic inflammation and infection, resulting in increased mucin and DNA concentrations. The viscoelastic properties of biofilms are regulated by biopolymers, including polysaccharides and DNA, and influence responses to antibiotics and phagocytosis. We hypothesize that targeted modulation of biofilm rheology will compromise structural integrity and increase antibiotic susceptibility and mucociliary transport. We evaluate biofilm rheology on the macro, micro, and nano scale as a function of treatment with a reducing agent, a biopolymer, and/or tobramycin to define the relationship between the viscoelastic properties of biofilms and susceptibility. Disruption of the biofilm architecture is associated with altered macroscopic and microscopic moduli, rapid vector permeability, increased antibiotic susceptibility, and improved mucociliary transport, suggesting that biofilm modulating therapeutics will improve the treatment of chronic respiratory infections in MOPD.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Matthew R. Markovetz
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William J. Kissner
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William L. Boone
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lucas M. Plott
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - David B. Hill
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina, Chapel Hill, NC, 27599, USA,Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Corresponding author. Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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8
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Hill DB, Button B, Rubinstein M, Boucher RC. Physiology and pathophysiology of human airway mucus. Physiol Rev 2022; 102:1757-1836. [PMID: 35001665 PMCID: PMC9665957 DOI: 10.1152/physrev.00004.2021] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 01/27/2023] Open
Abstract
The mucus clearance system is the dominant mechanical host defense system of the human lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid pumping and cough-dependent mechanisms, and mucus transport rates are heavily dependent on mucus concentration. Importantly, mucus transport rates are accurately predicted by the gel-on-brush model of the mucociliary apparatus from the relative osmotic moduli of the mucus and periciliary-glycocalyceal (PCL-G) layers. The fluid available to hydrate mucus is generated by transepithelial fluid transport. Feedback interactions between mucus concentrations and cilia beating, via purinergic signaling, coordinate Na+ absorptive vs Cl- secretory rates to maintain mucus hydration in health. In disease, mucus becomes hyperconcentrated (dehydrated). Multiple mechanisms derange the ion transport pathways that normally hydrate mucus in muco-obstructive lung diseases, e.g., cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), non-CF bronchiectasis (NCFB), and primary ciliary dyskinesia (PCD). A key step in muco-obstructive disease pathogenesis is the osmotic compression of the mucus layer onto the airway surface with the formation of adherent mucus plaques and plugs, particularly in distal airways. Mucus plaques create locally hypoxic conditions and produce airflow obstruction, inflammation, infection, and, ultimately, airway wall damage. Therapies to clear adherent mucus with hydrating and mucolytic agents are rational, and strategies to develop these agents are reviewed.
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Affiliation(s)
- David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, North Carolina
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael Rubinstein
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Mechanical Engineering and Materials Science, Biomedical Engineering, Physics, and Chemistry, Duke University, Durham, North Carolina
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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9
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Bengtson CD, Kim MD, Salathe M. Is CF airway inflammation still relevant in the era of highly effective modulators? J Cyst Fibros 2022; 21:901-903. [PMID: 36028422 DOI: 10.1016/j.jcf.2022.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Charles D Bengtson
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Michael D Kim
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Matthias Salathe
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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