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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. NONLINEAR PHENOMENA 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] [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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2
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Ferreira LMB, Cardoso VMO, Dos Santos Pedriz I, Souza MPC, Ferreira NN, Chorilli M, Gremião MPD, Zucolotto V. Understanding mucus modulation behavior of chitosan oligomers and dextran sulfate combining light scattering and calorimetric observations. Carbohydr Polym 2023; 306:120613. [PMID: 36746564 DOI: 10.1016/j.carbpol.2023.120613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/30/2022] [Accepted: 01/18/2023] [Indexed: 01/25/2023]
Abstract
This study reports the fundamental understanding of mucus-modulatory strategies combining charged biopolymers with distinct molecular weights and surface charges. Here, key biophysical evidence supports that low-molecular-weight (Mw) polycation chitosan oligosaccharides (COSs) and high-Mw polyanion dextran sulfate (DS) exhibit distinct thermodynamic signatures upon interaction with mucin (MUC), the main protein of mucus. While the COS → MUC microcalorimetric titrations released ~14 kcal/mol and ~60 kcal/mol, the DS → MUC titrations released ~1200 and ~1450 kcal/mol at pH of 4.5 and 6.8, respectively. The MPT-2 titrations of COS → MUC and DS → MUC indicated a greater zeta potential variation at pH = 4.5 (relative variation = 815 % and 351 %, respectively) than at pH = 6.8 (relative variation = 282 % and 136 %, respectively). Further, the resultant binary (COS-MUC) and ternary (COS-DS-MUC) complexes showed opposite behavior (aggregation and charge inversion events) according to the pH environment. Most importantly, the results indicate that electrostatics could not be the driving force that governs COS-MUC interactions. To account for this finding, we proposed a two-level abstraction model. Macro features emerge collectively from individual interactions occurring at the molecular level. Therefore, to understand the outcomes of mucus modulatory strategy based on charged biopolymers it is necessary to integrate both visions into the same picture.
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Affiliation(s)
- Leonardo M B Ferreira
- Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo (USP), 13566-590 São Carlos, Brazil.
| | - Valéria M O Cardoso
- Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo (USP), 13566-590 São Carlos, Brazil
| | - Igor Dos Santos Pedriz
- Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo (USP), 13566-590 São Carlos, Brazil
| | - Maurício P C Souza
- Department of Drugs and Pharmaceutics, School of Pharmaceutical Sciences, São Paulo State University (UNESP), 14800-903 Araraquara, SP, Brazil
| | - Natália N Ferreira
- Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo (USP), 13566-590 São Carlos, Brazil
| | - Marlus Chorilli
- Department of Drugs and Pharmaceutics, School of Pharmaceutical Sciences, São Paulo State University (UNESP), 14800-903 Araraquara, SP, Brazil
| | - Maria P D Gremião
- Department of Drugs and Pharmaceutics, School of Pharmaceutical Sciences, São Paulo State University (UNESP), 14800-903 Araraquara, SP, Brazil
| | - Valtencir Zucolotto
- Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo (USP), 13566-590 São Carlos, Brazil
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3
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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] [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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Mucins and CFTR: Their Close Relationship. Int J Mol Sci 2022; 23:ijms231810232. [PMID: 36142171 PMCID: PMC9499620 DOI: 10.3390/ijms231810232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/27/2022] [Accepted: 08/29/2022] [Indexed: 01/27/2023] Open
Abstract
Mucociliary clearance is a critical defense mechanism for the lungs governed by regionally coordinated epithelial cellular activities, including mucin secretion, cilia beating, and transepithelial ion transport. Cystic fibrosis (CF), an autosomal genetic disorder caused by the dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, is characterized by failed mucociliary clearance due to abnormal mucus biophysical properties. In recent years, with the development of highly effective modulator therapies, the quality of life of a significant number of people living with CF has greatly improved; however, further understanding the cellular biology relevant to CFTR and airway mucus biochemical interactions are necessary to develop novel therapies aimed at restoring CFTR gene expression in the lungs. In this article, we discuss recent advances of transcriptome analysis at single-cell levels that revealed a heretofore unanticipated close relationship between secretory MUC5AC and MUC5B mucins and CFTR in the lungs. In addition, we review recent findings on airway mucus biochemical and biophysical properties, focusing on how mucin secretion and CFTR-mediated ion transport are integrated to maintain airway mucus homeostasis in health and how CFTR dysfunction and restoration of function affect mucus properties.
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Puri V, Kaur VP, Singh A, Singh C. Recent advances on drug delivery applications of mucopenetrative/mucoadhesive particles: A review. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Coronavirus disease 2019 (COVID-19) is a worldwide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has affected millions of lives. Individuals who survive severe COVID-19 can experience sustained respiratory symptoms that persist for months after initial infection. In other airway diseases, abnormal airway mucus contributes to sustained airway symptoms. However, the impact of SARS-CoV-2 on airway mucus has received limited attention. In the current review, we assess literature describing the impact of SARS-CoV-2 on airway pathophysiology with specific emphasis on mucus production. Accumulating evidence suggests that the 2 major secreted airway mucin glycoproteins, MUC5AC and MUC5B, are abnormal in some patients with COVID-19. Aberrations in MUC5AC or MUC5B in response to SARS-CoV-2 infection are likely due to inflammation, though the responsible mechanisms have yet to be determined. Thus, we also provide a proposed model highlighting mechanisms that can contribute to acute and sustained mucus abnormalities in SARS-CoV-2, with an emphasis on inflammatory cells and mediators, including mast cells and histamine. Last, we bring to light the challenges of studying abnormal mucus production in SARS-CoV-2 infections and discuss the strengths and limitations of model systems commonly used to study COVID-19. The evidence to date suggests that ferrets, nonhuman primates, and cats may have advantages over other models to investigate mucus in COVID-19.
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Methods of Sputum and Mucus Assessment for Muco-Obstructive Lung Diseases in 2022: Time to “Unplug” from Our Daily Routine! Cells 2022; 11:cells11050812. [PMID: 35269434 PMCID: PMC8909676 DOI: 10.3390/cells11050812] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 01/27/2023] Open
Abstract
Obstructive lung diseases, such as chronic obstructive pulmonary disease, asthma, or non-cystic fibrosis bronchiectasis, share some major pathophysiological features: small airway involvement, dysregulation of adaptive and innate pulmonary immune homeostasis, mucus hyperproduction, and/or hyperconcentration. Mucus regulation is particularly valuable from a therapeutic perspective given it contributes to airflow obstruction, symptom intensity, disease severity, and to some extent, disease prognosis in these diseases. It is therefore crucial to understand the mucus constitution of our patients, its behavior in a stable state and during exacerbation, and its regulatory mechanisms. These are all elements representing potential therapeutic targets, especially in the era of biologics. Here, we first briefly discuss the composition and characteristics of sputum. We focus on mucus and mucins, and then elaborate on the different sample collection procedures and how their quality is ensured. We then give an overview of the different direct analytical techniques available in both clinical routine and more experimental settings, giving their advantages and limitations. We also report on indirect mucus assessment procedures (questionnaires, high-resolution computed tomography scanning of the chest, lung function tests). Finally, we consider ways of integrating these techniques with current and future therapeutic options. Cystic fibrosis will not be discussed given its monogenic nature.
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Morrison CB, Shaffer KM, Araba KC, Markovetz MR, Wykoff JA, Quinney NL, Hao S, Delion MF, Flen AL, Morton LC, Liao J, Hill DB, Drumm ML, O’Neal WK, Kesimer M, Gentzsch M, Ehre C. Treatment of cystic fibrosis airway cells with CFTR modulators reverses aberrant mucus properties via hydration. Eur Respir J 2022; 59:13993003.00185-2021. [PMID: 34172469 PMCID: PMC8859811 DOI: 10.1183/13993003.00185-2021] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/11/2021] [Indexed: 02/05/2023]
Abstract
QUESTION Cystic fibrosis (CF) is characterised by the accumulation of viscous adherent mucus in the lungs. While several hypotheses invoke a direct relationship with cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction (i.e. acidic airway surface liquid (ASL) pH, low bicarbonate (HCO3 -) concentration, airway dehydration), the dominant biochemical alteration of CF mucus remains unknown. MATERIALS/METHODS We characterised a novel cell line (CFTR-KO Calu3 cells) and the responses of human bronchial epithelial (HBE) cells from subjects with G551D or F508del mutations to ivacaftor and elexacaftor-tezacaftor-ivacaftor. A spectrum of assays such as short-circuit currents, quantitative PCR, ASL pH, Western blotting, light scattering/refractometry (size-exclusion chromatography with inline multi-angle light scattering), scanning electron microscopy, percentage solids and particle tracking were performed to determine the impact of CFTR function on mucus properties. RESULTS Loss of CFTR function in Calu3 cells resulted in ASL pH acidification and mucus hyperconcentration (dehydration). Modulation of CFTR in CF HBE cells did not affect ASL pH or mucin mRNA expression, but decreased mucus concentration, relaxed mucus network ultrastructure and improved mucus transport. In contrast with modulator-treated cells, a large fraction of airway mucins remained attached to naïve CF cells following short apical washes, as revealed by the use of reducing agents to remove residual mucus from the cell surfaces. Extended hydration, but not buffers alkalised with sodium hydroxide or HCO3 -, normalised mucus recovery to modulator-treated cell levels. CONCLUSION These results indicate that airway dehydration, not acidic pH and/or low [HCO3 -], is responsible for abnormal mucus properties in CF airways and CFTR modulation predominantly restores normal mucin entanglement.
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Affiliation(s)
- Cameron B. Morrison
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Kendall M. Shaffer
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Kenza C. Araba
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Matthew R. Markovetz
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Jason A. Wykoff
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Nancy L. Quinney
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Shuyu Hao
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill
| | - Martial F. Delion
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Alexis L. Flen
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Lisa C. Morton
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Jimmy Liao
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - David B. Hill
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill,Department of Physics and Astronomy, The University of North Carolina at Chapel Hill
| | - Mitchell L. Drumm
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine
| | - Wanda K. O’Neal
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Mehmet Kesimer
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Martina Gentzsch
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill,Division of Pediatric Pulmonology, The University of North Carolina at Chapel Hill,Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill
| | - Camille Ehre
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill,Division of Pediatric Pulmonology, The University of North Carolina at Chapel Hill,To whom correspondence should be addressed:
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Du J, Lewis OL, Keener JP, Fogelson AL. Modeling and Simulation of the Ion-Binding-Mediated Swelling Dynamics of Mucin-like Polyelectrolyte Gels. Gels 2021; 7:244. [PMID: 34940304 PMCID: PMC8702155 DOI: 10.3390/gels7040244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 12/13/2022] Open
Abstract
Volume phase transitions in polyeletrolyte gels play important roles in many biophysical processes such as DNA packaging, nerve excitation, and cellular secretion. The swelling and deswelling of these charged polymer gels depend strongly on their ionic environment. In this paper, we present an extension to our previous two-fluid model for ion-binding-mediated gel swelling. The extended model eliminates the assumptions about the size similarity between the network and solvent particles, which makes it suitable for investigating of a large family of biologically relevant problems. The model treats the polyeletrolyte gel as a mixture of two materials, the network and the solvent. The dynamics of gel swelling is governed by the balance between the mechanical and chemical forces on each of these two materials. Simulations based on the model illustrate that the chemical forces are significantly influenced by the binding/unbinding reactions between the ions and the network, as well as the resulting distribution of charges within the gel. The dependence of the swelling rate on ionic bath concentrations is analyzed and this analysis highlights the importance of the electromigration of ions and the induced electric field in regulating gel swelling.
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Affiliation(s)
- Jian Du
- Department of Mathematical Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Owen L. Lewis
- Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM 87106, USA;
| | - James P. Keener
- Department of Mathematics and Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; (J.P.K.); (A.L.F.)
| | - Aaron L. Fogelson
- Department of Mathematics and Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; (J.P.K.); (A.L.F.)
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McShane A, Bath J, Jaramillo AM, Ridley C, Walsh AA, Evans CM, Thornton DJ, Ribbeck K. Mucus. Curr Biol 2021; 31:R938-R945. [PMID: 34375594 DOI: 10.1016/j.cub.2021.06.093] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Mucus is a slimy hydrogel that lines the mucosal surfaces in our body, including the intestines, stomach, eyes, lungs and urogenital tract. This glycoprotein-rich network is truly the jack of all trades. As a barrier, it lubricates surfaces, protects our cells from physical stress, and selectively allows the passage of nutrients while clearing out pathogens and debris. As a home to our microbiota, it supports a level of microbial diversity that is unattainable with most culture methods. As a reservoir of complex carbohydrate structures called glycans, it plays critical roles in controlling cell adhesion and signaling, and it alters the behavior and spatial distribution of microbes. On top of all this, mucus regulates the passage of sperm during fertilization, heals wounds, helps us smell, and prevents the stomach from digesting itself, to name just a few of its functions. Given these impressive features, it is no wonder that mucus crosses boundaries of species and kingdoms - mucus gels are made by organisms ranging from the simplest metazoans to corals, snails, fish, and frogs. It is also no surprise that mucus is exploited in everyday applications, including foods, cosmetics, and other products relevant to medicine and industry.
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Affiliation(s)
- Abigail McShane
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02141, USA; National Science Foundation Graduate Research Fellowship Program
| | - Jade Bath
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02141, USA
| | - Ana M Jaramillo
- Pulmonary Sciences, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Caroline Ridley
- Division of Infection, Immunity, and Respiratory Medicine, University of Manchester, Manchester M13 9PT, UK
| | - Agnes A Walsh
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02141, USA
| | - Christopher M Evans
- Pulmonary Sciences, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - David J Thornton
- Division of Infection, Immunity, and Respiratory Medicine, University of Manchester, Manchester M13 9PT, UK.
| | - Katharina Ribbeck
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02141, USA.
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11
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Arias SL, Brito IL. Biophysical determinants of biofilm formation in the gut. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021; 18:100275. [PMID: 34504987 PMCID: PMC8423371 DOI: 10.1016/j.cobme.2021.100275] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The gastrointestinal (GI) tract harbors the most complex microbial ecosystem in the human body. The mucosal layer that covers the GI tract serves as a polymer-based defensive barrier that prevents the microbiome from reaching the epithelium and disseminating inside the body. Colonization of the mucus may result in the formation of structured polymicrobial communities or biofilms, a hallmark in pathologies such as colorectal cancer, inflammatory bowel disease, and chronic gut wounds. However, the mechanisms by which multispecies biofilms establish on the gut mucosa is unknown. Whether mucus-associated biofilms exist as part of a healthy mucosal barrier is still debated. Here, we discuss the impact that diet and microbial-derived polymers has on mucus structure and microcolony formation and highlight relevant biophysical forces that further shape nascent biofilms.
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Affiliation(s)
- Sandra L Arias
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850
| | - Ilana L Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850
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12
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Mussel M, Basser PJ, Horkay F. Ion-Induced Volume Transition in Gels and Its Role in Biology. Gels 2021; 7:20. [PMID: 33670826 PMCID: PMC8005988 DOI: 10.3390/gels7010020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
Incremental changes in ionic composition, solvent quality, and temperature can lead to reversible and abrupt structural changes in many synthetic and biopolymer systems. In the biological milieu, this nonlinear response is believed to play an important functional role in various biological systems, including DNA condensation, cell secretion, water flow in xylem of plants, cell resting potential, and formation of membraneless organelles. While these systems are markedly different from one another, a physicochemical framework that treats them as polyelectrolytes, provides a means to interpret experimental results and make in silico predictions. This article summarizes experimental results made on ion-induced volume phase transition in a polyelectrolyte model gel (sodium polyacrylate) and observations on the above-mentioned biological systems indicating the existence of a steep response.
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Affiliation(s)
- Matan Mussel
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | | | - Ferenc Horkay
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
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Optimizations of In Vitro Mucus and Cell Culture Models to Better Predict In Vivo Gene Transfer in Pathological Lung Respiratory Airways: Cystic Fibrosis as an Example. Pharmaceutics 2020; 13:pharmaceutics13010047. [PMID: 33396283 PMCID: PMC7823756 DOI: 10.3390/pharmaceutics13010047] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 11/17/2022] Open
Abstract
The respiratory epithelium can be affected by many diseases that could be treated using aerosol gene therapy. Among these, cystic fibrosis (CF) is a lethal inherited disease characterized by airways complications, which determine the life expectancy and the effectiveness of aerosolized treatments. Beside evaluations performed under in vivo settings, cell culture models mimicking in vivo pathophysiological conditions can provide complementary insights into the potential of gene transfer strategies. Such models must consider multiple parameters, following the rationale that proper gene transfer evaluations depend on whether they are performed under experimental conditions close to pathophysiological settings. In addition, the mucus layer, which covers the epithelial cells, constitutes a physical barrier for gene delivery, especially in diseases such as CF. Artificial mucus models featuring physical and biological properties similar to CF mucus allow determining the ability of gene transfer systems to effectively reach the underlying epithelium. In this review, we describe mucus and cellular models relevant for CF aerosol gene therapy, with a particular emphasis on mucus rheology. We strongly believe that combining multiple pathophysiological features in single complex cell culture models could help bridge the gaps between in vitro and in vivo settings, as well as viral and non-viral gene delivery strategies.
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14
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Probing the effect of aroma compounds on the hydrodynamic properties of mucin glycoproteins. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:799-808. [PMID: 33185715 PMCID: PMC7701130 DOI: 10.1007/s00249-020-01475-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/12/2020] [Accepted: 10/23/2020] [Indexed: 11/29/2022]
Abstract
Aroma compounds are diverse low molecular weight organic molecules responsible for the flavour of food, medicines or cosmetics. Natural and artificial aroma compounds are manufactured and used by the industry to enhance the flavour and fragrance of products. While the low concentrations of aroma compounds present in food may leave no effect on the structural integrity of the mucosa, the effect of concentrated aroma volatiles is not well understood. At high concentrations, like those found in some flavoured products such as e-cigarettes, some aroma compounds are suggested to elicit a certain degree of change in the mucin glycoprotein network, depending on their functional group. These effects are particularly associated with carbonyl compounds such as aldehydes and ketones, but also phenols which may interact with mucin and other glycoproteins through other interaction mechanisms. This study demonstrates the formation of such interactions in vitro through the use of molecular hydrodynamics. Sedimentation velocity studies reveal that the strength of the carbonyl compound interaction is influenced by compound hydrophobicity, in which the more reactive short chain compounds show the largest increase in mucin-aroma sedimentation coefficients. By contrast, the presence of groups that increases the steric hindrance of the carbonyl group, such as ketones, produced a milder effect. The interaction effects were further demonstrated for hexanal using size exclusion chromatography light scattering (SEC-MALS) and intrinsic viscosity. In addition, phenolic aroma compounds were identified to reduce the sedimentation coefficient of mucin, which is consistent with interactions in the non-glycosylated mucin region.
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15
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Curnutt A, Smith K, Darrow E, Walters KB. Chemical and Microstructural Characterization of pH and [Ca 2+] Dependent Sol-Gel Transitions in Mucin Biopolymer. Sci Rep 2020; 10:8760. [PMID: 32472040 PMCID: PMC7260187 DOI: 10.1038/s41598-020-65392-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 04/29/2020] [Indexed: 12/22/2022] Open
Abstract
Mucus is responsible for controlling transport and barrier function in biological systems, and its properties can be significantly affected by compositional and environmental changes. In this study, the impacts of pH and CaCl2 were examined on the solution-to-gel transition of mucin, the primary structural component of mucus. Microscale structural changes were correlated with macroscale viscoelastic behavior as a function of pH and calcium addition using rheology, dynamic light scattering, zeta potential, surface tension, and FTIR spectroscopic characterization. Mucin solutions transitioned from solution to gel behavior between pH 4–5 and correspondingly displayed a more than ten-fold increase in viscoelastic moduli. Addition of CaCl2 increased the sol-gel transition pH value to ca. 6, with a twofold increase in loss moduli at low frequencies and ten-fold increase in storage modulus. Changing the ionic conditions—specifically [H+] and [Ca2+] —modulated the sol-gel transition pH, isoelectric point, and viscoelastic properties due to reversible conformational changes with mucin forming a network structure via non-covalent cross-links between mucin chains.
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Affiliation(s)
- Austin Curnutt
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Kaylee Smith
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Emily Darrow
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Keisha B Walters
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, 73019, USA.
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16
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Ehre C. [Mucus buildup: the starting point of cystic fibrosis lung disease pathogenesis]. Med Sci (Paris) 2020; 35:1217-1220. [PMID: 31903945 DOI: 10.1051/medsci/2019234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, États-Unis - Division of Pediatric Pulmonology, University of North Carolina at Chapel Hill, États-Unis
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17
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Atanasova KR, Reznikov LR. Strategies for measuring airway mucus and mucins. Respir Res 2019; 20:261. [PMID: 31752894 PMCID: PMC6873701 DOI: 10.1186/s12931-019-1239-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 11/11/2019] [Indexed: 12/17/2022] Open
Abstract
Mucus secretion and mucociliary transport are essential defense mechanisms of the airways. Deviations in mucus composition and secretion can impede mucociliary transport and elicit airway obstruction. As such, mucus abnormalities are hallmark features of many respiratory diseases, including asthma, cystic fibrosis and chronic obstructive pulmonary disease (COPD). Studying mucus composition and its physical properties has therefore been of significant interest both clinically and scientifically. Yet, measuring mucus production, output, composition and transport presents several challenges. Here we summarize and discuss the advantages and limitations of several techniques from five broadly characterized strategies used to measure mucus secretion, composition and mucociliary transport, with an emphasis on the gel-forming mucins. Further, we summarize advances in the field, as well as suggest potential areas of improvement moving forward.
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Affiliation(s)
- Kalina R Atanasova
- Department of Physiological Sciences, University of Florida, 1333 Center Drive, PO Box 100144, Gainesville, FL, 32610, USA
| | - Leah R Reznikov
- Department of Physiological Sciences, University of Florida, 1333 Center Drive, PO Box 100144, Gainesville, FL, 32610, USA.
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18
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Abstract
Exocytosis of secreted mucins is the final step in their intracellular processing, resulting in their release into the airway lumen to interact with water and ions to form mucus. Mucins are secreted at a low baseline rate and a high stimulated rate, and both rates are regulated by second messengers acting on components of the exocytic machinery. The principal physiologic function of the low baseline rate is to support steady-state mucociliary clearance of inhaled particles and pathogens that enter the airways during normal breathing. Even in the setting of mucin hyperproduction, baseline secretion generally does not induce mucus occlusion. The principal physiologic function of the high stimulated rate of secretion from both submucosal glands and surface goblet cells in proximal airways appears to be to sweep away larger particles, whereas in distal airways it appears to act in concert with mucin hyperproduction to induce mucus occlusion to trap migrating helminths. Pathophysiologically, stimulated mucin secretion in the setting of mucin hyperproduction from allergic or other types of airway inflammation in the absence of helminth infection causes airflow obstruction and infection. Molecular components of the mucin exocytic machinery are increasingly being identified, and surprisingly, many components are not shared between baseline and stimulated machines. The physiologic significance of the presence of two distinct molecular machines is not yet known, such as whether these interact selectively with secretory granules of different sizes or contents. A full understanding of the mechanism and regulation of airway mucin secretion will provide further insight into pathophysiologic processes and may identify therapeutic strategies to alleviate obstructive airway diseases.
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19
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Morrison CB, Markovetz MR, Ehre C. Mucus, mucins, and cystic fibrosis. Pediatr Pulmonol 2019; 54 Suppl 3:S84-S96. [PMID: 31715083 PMCID: PMC6853602 DOI: 10.1002/ppul.24530] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/06/2019] [Indexed: 02/06/2023]
Abstract
Cystic fibrosis (CF) is both the most common and most lethal genetic disease in the Caucasian population. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and is characterized by the accumulation of thick, adherent mucus plaques in multiple organs, of which the lungs, gastrointestinal tract and pancreatic ducts are the most commonly affected. A similar pathogenesis cascade is observed in all of these organs: loss of CFTR function leads to altered ion transport, consisting of decreased chloride and bicarbonate secretion via the CFTR channel and increased sodium absorption via epithelial sodium channel upregulation. Mucosa exposed to changes in ionic concentrations sustain severe pathophysiological consequences. Altered mucus biophysical properties and weakened innate defense mechanisms ensue, furthering the progression of the disease. Mucins, the high-molecular-weight glycoproteins responsible for the viscoelastic properties of the mucus, play a key role in the disease but the actual mechanism of mucus accumulation is still undetermined. Multiple hypotheses regarding the impact of CFTR malfunction on mucus have been proposed and are reviewed here. (a) Dehydration increases mucin monomer entanglement, (b) defective Ca2+ chelation compromises mucin expansion, (c) ionic changes alter mucin interactions, and (d) reactive oxygen species increase mucin crosslinking. Although one biochemical change may dominate, it is likely that all of these mechanisms play some role in the progression of CF disease. This article discusses recent findings on the initial cause(s) of aberrant mucus properties in CF and examines therapeutic approaches aimed at correcting mucus properties.
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Affiliation(s)
- Cameron Bradley Morrison
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Matthew Raymond Markovetz
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Camille Ehre
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Division of Pediatric Pulmonology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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20
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Abstract
Mucus selectively controls the transport of molecules, particulate matter, and microorganisms to the underlying epithelial layer. It may be desirable to weaken the mucus barrier to enable effective delivery of drug carriers. Alternatively, the mucus barrier can be strengthened to prevent epithelial interaction with pathogenic microbes or other exogenous materials. The dynamic mucus layer can undergo changes in structure (e.g., pore size) and/or composition (e.g., protein concentrations, mucin glycosylation) in response to stimuli that occur naturally or are purposely administered, thus altering its barrier function. This review outlines mechanisms by which mucus provides a selective barrier and methods to engineer the mucus layer from the perspective of strengthening or weakening its barrier properties. In addition, we discuss strategic design of drug carriers and dosing formulation properties for efficient delivery across the mucus barrier.
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Affiliation(s)
- T L Carlson
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, USA;
| | - J Y Lock
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, USA
| | - R L Carrier
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, USA; .,Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, USA
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21
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Javitt G, Calvo MLG, Albert L, Reznik N, Ilani T, Diskin R, Fass D. Intestinal Gel-Forming Mucins Polymerize by Disulfide-Mediated Dimerization of D3 Domains. J Mol Biol 2019; 431:3740-3752. [PMID: 31310764 PMCID: PMC6739602 DOI: 10.1016/j.jmb.2019.07.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 01/06/2023]
Abstract
The mucin 2 glycoprotein assembles into a complex hydrogel that protects intestinal epithelia and houses the gut microbiome. A major step in mucin 2 assembly is further multimerization of preformed mucin dimers, thought to produce a honeycomb-like arrangement upon hydrogel expansion. Important open questions are how multiple mucin 2 dimers become covalently linked to one another and how mucin 2 multimerization compares with analogous processes in related polymers such as respiratory tract mucins and the hemostasis protein von Willebrand factor. Here we report the x-ray crystal structure of the mucin 2 multimerization module, found to form a dimer linked by two intersubunit disulfide bonds. The dimer structure calls into question the current model for intestinal mucin assembly, which proposes disulfide-mediated trimerization of the same module. Key residues making interactions across the dimer interface are highly conserved in intestinal mucin orthologs, supporting the physiological relevance of the observed quaternary structure. With knowledge of the interface residues, it can be demonstrated that many of these amino acids are also present in other mucins and in von Willebrand factor, further indicating that the stable dimer arrangement reported herein is likely to be shared across this functionally broad protein family. The mucin 2 module structure thus reveals the manner by which both mucins and von Willebrand factor polymerize, drawing deep structural parallels between macromolecular assemblies critical to mucosal epithelia and the vasculature.
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Affiliation(s)
- Gabriel Javitt
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | | | - Lis Albert
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nava Reznik
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tal Ilani
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ron Diskin
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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22
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Preska Steinberg A, Wang ZG, Ismagilov RF. Food Polyelectrolytes Compress the Colonic Mucus Hydrogel by a Donnan Mechanism. Biomacromolecules 2019; 20:2675-2683. [PMID: 31244018 DOI: 10.1021/acs.biomac.9b00442] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Systems consisting of a polyelectrolyte solution in contact with a cross-linked polyelectrolyte network are ubiquitous (e.g., biofilms, drug-delivering hydrogels, and mammalian extracellular matrices), yet the underlying physics governing these interactions is not well understood. Here, we find that carboxymethyl cellulose, a polyelectrolyte commonly found in processed foods and associated with inflammation and obesity, compresses the colonic mucus hydrogel (a key regulator of host-microbe interactions and a protective barrier) in mice. The extent of this polyelectrolyte-induced compression is enhanced by the degree of polymer negative charge. Through animal experiments and numerical calculations, we find that this phenomenon can be described by a Donnan mechanism. Further, the observed behavior can be quantitatively described by a simple, one-parameter model. This work suggests that polymer charge should be considered when developing food products because of its potential role in modulating the protective properties of colonic mucus.
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23
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Stowell CP, Stowell SR. Biologic roles of the ABH and Lewis histo-blood group antigens Part I: infection and immunity. Vox Sang 2019; 114:426-442. [PMID: 31070258 DOI: 10.1111/vox.12787] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 12/22/2022]
Abstract
The ABH and Lewis antigens were among the first of the human red blood cell polymorphisms to be identified and, in the case of the former, play a dominant role in transfusion and transplantation. But these two therapies are largely twentieth century innovations, and the ABH and related carbohydrate antigens are not only expressed on a very wide range of human tissues, but were present in primates long before modern humans evolved. Although we have learned a great deal about the biochemistry and genetics of these structures, the biological roles that they play in human health and disease are incompletely understood. This review and its companion, to appear in a later issue of Vox Sanguinis, will focus on a few of the biologic and pathologic processes which appear to be affected by histo-blood group phenotype. The first of the two reviews will explore the interactions of two bacteria with the ABH and Lewis glycoconjugates of their human host cells, and describe the possible connections between the immune response of the human host to infection and the development of the AB-isoagglutinins. The second review will describe the relationship between ABO phenotype and thromboembolic disease, cardio-vascular disease states, and general metabolism.
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Affiliation(s)
- Christopher P Stowell
- Blood Transfusion Service, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Sean R Stowell
- Center for Apheresis, Center for Transfusion and Cellular Therapies, Emory Hospital, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pathology, Emory University School of Medicine, Atlanta, GA, USA
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24
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Hierarchical self-assembly and emergent function of densely glycosylated peptide nanofibers. Commun Chem 2019. [DOI: 10.1038/s42004-019-0154-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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25
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Jaramillo AM, Piccotti L, Velasco WV, Delgado ASH, Azzegagh Z, Chung F, Nazeer U, Farooq J, Brenner J, Parker-Thornburg J, Scott BL, Evans CM, Adachi R, Burns AR, Kreda SM, Tuvim MJ, Dickey BF. Different Munc18 proteins mediate baseline and stimulated airway mucin secretion. JCI Insight 2019; 4:124815. [PMID: 30721150 PMCID: PMC6483006 DOI: 10.1172/jci.insight.124815] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/31/2019] [Indexed: 12/15/2022] Open
Abstract
Airway mucin secretion is necessary for ciliary clearance of inhaled particles and pathogens but can be detrimental in pathologies such as asthma and cystic fibrosis. Exocytosis in mammals requires a Munc18 scaffolding protein, and airway secretory cells express all 3 Munc18 isoforms. Using conditional airway epithelial cell-deletant mice, we found that Munc18a has the major role in baseline mucin secretion, Munc18b has the major role in stimulated mucin secretion, and Munc18c does not function in mucin secretion. In an allergic asthma model, Munc18b deletion reduced airway mucus occlusion and airflow resistance. In a cystic fibrosis model, Munc18b deletion reduced airway mucus occlusion and emphysema. Munc18b deficiency in the airway epithelium did not result in any abnormalities of lung structure, particle clearance, inflammation, or bacterial infection. Our results show that regulated secretion in a polarized epithelial cell may involve more than one exocytic machine at the apical plasma membrane and that the protective roles of mucin secretion can be preserved while therapeutically targeting its pathologic roles.
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Affiliation(s)
- Ana M. Jaramillo
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Institute of Bioscience and Technology, Texas A&M University Health Science Center, Houston, Texas, USA
| | - Lucia Piccotti
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Walter V. Velasco
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Zoulikha Azzegagh
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Felicity Chung
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Usman Nazeer
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Junaid Farooq
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Josh Brenner
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jan Parker-Thornburg
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Brenton L. Scott
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Christopher M. Evans
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver School of Medicine, Aurora, Colorado, USA
| | - Roberto Adachi
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Alan R. Burns
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Silvia M. Kreda
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michael J. Tuvim
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Burton F. Dickey
- Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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26
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Dušková-Smrčková M, Dušek K. How to Force Polymer Gels to Show Volume Phase Transitions. ACS Macro Lett 2019; 8:272-278. [PMID: 35650828 DOI: 10.1021/acsmacrolett.8b00987] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Relatively few polymer gels are known to show volume phase transition where the gels undergo an abrupt change in the degree of swelling by passing through a three-phase equilibrium. Characteristic for such transition is the existence of van der Waals (vdW) loop on the dependence of solvent chemical potential versus polymer concentration. For the χ-induced transition, the existence of vdW loop is determined by the concentration dependence of the interaction function. It is shown that expansive mechanical strains can assist in development of the vdW loop. Systems characterized by continuous change of the degree of swelling transform upon such strain into ones where the degree of swelling changes much and abruptly. Also, expansive modes of strain can make the transition wider and more robust in gels where transition is already observed under free swelling condition. The possibility to induce the volume phase transition by external stresses can be utilized for finding other stimuli sensitive gels, strengthening of gel response, and in modeling of properties of gel constructs by Finite Element Method.
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Affiliation(s)
- Miroslava Dušková-Smrčková
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Karel Dušek
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
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27
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Demouveaux B, Gouyer V, Magnien M, Plet S, Gottrand F, Narita T, Desseyn JL. [Gel-forming mucins structure governs mucus gels viscoelasticity]. Med Sci (Paris) 2018; 34:806-812. [PMID: 30451674 DOI: 10.1051/medsci/2018206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mucus is the first line of innate mucosal defense in all mammals. Gel‑forming mucins control the rheological properties of mucus hydrogels by forming a network in which hydrophilic and hydrophobic regions coexist, and it has been revealed that the network is formed through both covalent links and reversible links such as hydrophobic interactions in order to modulate the structure as a function of the physiological necessities. Here, we review the structure and functions of the mucus in terms of the gel-forming mucins protein-protein interactions, also called interactome. Since it is difficult to characterize the low energy reversible interactions due to their dependence on physico-chemical environment, their role is not well understood. Still, they constitute a promising target to counteract mucus abnormalities observed in mucus-associated diseases.
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Affiliation(s)
- Bastien Demouveaux
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Valérie Gouyer
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Mylène Magnien
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Ségolène Plet
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Frédéric Gottrand
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Tetsuharu Narita
- PSL Research University, UPMC Univ. Paris 06, ESPCI Paris, CNRS UMR 7615, Laboratoire Sciences et Ingénierie de la Matière Molle, 10, rue Vauquelin, 75231, Paris Cedex 05, France - Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japon
| | - Jean-Luc Desseyn
- Inserm, Université de Lille, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
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28
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Yamashita MSDA, Melo EO. Mucin 2 (MUC2) promoter characterization: an overview. Cell Tissue Res 2018; 374:455-463. [PMID: 30218241 DOI: 10.1007/s00441-018-2916-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 08/13/2018] [Indexed: 12/24/2022]
Abstract
Transgenic livestock have been studied with a well-known interest in improving quantitative and qualitative traits. In order to direct heterologous gene expression, it is indispensable to identify and characterize a promoter suitable for directing the expression of the gene of interest (GOI) in a tissue-specific way. The gastrointestinal tract is a desirable target for gene expression in several mammalian models. Throughout the surface of the intestinal epithelium, there is an intricate polymer network, formed by gel-forming mucins (especially MUC2 and MUC5AC, of which MUC2 is the major one), which plays a protective role due to the formation of a physical, chemical and immunological barrier between the organism and the environment. The characterization of the gel-forming mucins is difficult because of their large size and repetitive DNA sequences and domains. The main mucin in the small and large intestine, mucin 2 (MUC2), is expressed specifically in goblet cells. MUC2 plays an important role in intestinal homeostasis and its disruption is associated with several diseases and carcinomas. This mucin is also an important marker for elucidating mechanisms that regulate differentiation of the secretory cell lineage. This review presents the state of the art of MUC2 promoter structure and functional characterization.
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Affiliation(s)
| | - Eduardo O Melo
- EMBRAPA Genetic Resources and Biotechnology, PqEB Av W5 Norte, Brasilia, DF, 70770-917, Brazil
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29
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Corfield AP. The Interaction of the Gut Microbiota with the Mucus Barrier in Health and Disease in Human. Microorganisms 2018; 6:microorganisms6030078. [PMID: 30072673 PMCID: PMC6163557 DOI: 10.3390/microorganisms6030078] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/25/2018] [Accepted: 07/30/2018] [Indexed: 02/07/2023] Open
Abstract
Glycoproteins are major players in the mucus protective barrier in the gastrointestinal and other mucosal surfaces. In particular the mucus glycoproteins, or mucins, are responsible for the protective gel barrier. They are characterized by their high carbohydrate content, present in their variable number, tandem repeat domains. Throughout evolution the mucins have been maintained as integral components of the mucosal barrier, emphasizing their essential biological status. The glycosylation of the mucins is achieved through a series of biosynthetic pathways processes, which generate the wide range of glycans found in these molecules. Thus mucins are decorated with molecules having information in the form of a glycocode. The enteric microbiota interacts with the mucosal mucus barrier in a variety of ways in order to fulfill its many normal processes. How bacteria read the glycocode and link to normal and pathological processes is outlined in the review.
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Affiliation(s)
- Anthony P Corfield
- Mucin Research Group, School of Clinical Sciences, Bristol Royal Infirmary, Level 7, Marlborough Street, Bristol BS2 8HW, UK.
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30
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Ferreira LM, Alonso JD, Kiill CP, Ferreira NN, Buzzá HH, Martins de Godoi DR, de Britto D, Assis OBG, Seraphim TV, Borges JC, Gremião MPD. Exploiting supramolecular interactions to produce bevacizumab-loaded nanoparticles for potential mucosal delivery. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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31
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Nguyen TL, Perlman CE. Tracheal acid or surfactant instillation raises alveolar surface tension. J Appl Physiol (1985) 2018; 125:1357-1367. [PMID: 29771610 DOI: 10.1152/japplphysiol.00397.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Whether alveolar liquid surface tension, T, is elevated in the acute respiratory distress syndrome (ARDS) has not been demonstrated in situ in the lungs. Neither is it known how exogenous surfactant, which has failed to treat ARDS, affects in situ T. We aim to determine T in an acid-aspiration ARDS model before and after exogenous surfactant administration. In isolated rat lungs, we combine servo-nulling pressure measurement and confocal microscopy to determine alveolar liquid T according to the Laplace relation. Administering 0.01 N (pH 1.9) HCl solution by alveolar injection or tracheal instillation, to model gastric liquid aspiration, raises T. Subsequent surfactant administration fails to normalize T. Furthermore, in normal lungs, tracheal instillation of control saline or exogenous surfactant raises T. Lavaging the trachea with saline and injecting the lavage solution into the alveolus raises T, suggesting that tracheal instillation may wash T-raising airway contents to the alveolus. Adding 0.01 N HCl or 5 mM CaCl2-either of which aggregates mucins-to tracheal lavage solution reduces or eliminates the effect of lavage solution on alveolar T. Following tracheal saline instillation, liquid suctioned directly out of alveoli through a micropipette contains mucins. Additionally, alveolar injection of gastric mucin solution raises T. We conclude that 1) tracheal liquid instillation likely washes T-raising mucins to the alveolus and 2) even exogenous surfactant that could be delivered mucin-free to the alveolus might not normalize T in acid-aspiration ARDS. NEW & NOTEWORTHY We demonstrate in situ in isolated lungs that surface tension is elevated in an acid-aspiration acute respiratory distress syndrome (ARDS) model. Following tracheal liquid instillation, also in isolated lungs, we directly sample alveolar liquid. We find that liquid instillation into normal lungs washes mucins to the alveolus, thereby raising alveolar surface tension. Furthermore, even if exogenous surfactant could be delivered mucin-free to the alveolus, exogenous surfactant might fail to normalize alveolar surface tension in acid-aspiration ARDS.
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Affiliation(s)
- Tam L Nguyen
- Department of Biomedical Engineering, Stevens Institute of Technology , Hoboken, New Jersey
| | - Carrie E Perlman
- Department of Biomedical Engineering, Stevens Institute of Technology , Hoboken, New Jersey
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Meldrum OW, Yakubov GE, Bonilla MR, Deshmukh O, McGuckin MA, Gidley MJ. Mucin gel assembly is controlled by a collective action of non-mucin proteins, disulfide bridges, Ca 2+-mediated links, and hydrogen bonding. Sci Rep 2018; 8:5802. [PMID: 29643478 PMCID: PMC5895598 DOI: 10.1038/s41598-018-24223-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 03/27/2018] [Indexed: 12/24/2022] Open
Abstract
Mucus is characterized by multiple levels of assembly at different length scales which result in a unique set of rheological (flow) and mechanical properties. These physical properties determine its biological function as a highly selective barrier for transport of water and nutrients, while blocking penetration of pathogens and foreign particles. Altered integrity of the mucus layer in the small intestine has been associated with a number of gastrointestinal tract pathologies such as Crohn’s disease and cystic fibrosis. In this work, we uncover an intricate hierarchy of intestinal mucin (Muc2) assembly and show how complex rheological properties emerge from synergistic interactions between mucin glycoproteins, non-mucin proteins, and Ca2+. Using a novel method of mucus purification, we demonstrate the mechanism of assembly of Muc2 oligomers into viscoelastic microscale domains formed via hydrogen bonding and Ca2+-mediated links, which require the joint presence of Ca2+ ions and non-mucin proteins. These microscale domains aggregate to form a heterogeneous yield stress gel-like fluid, the macroscopic rheological properties of which are virtually identical to that of native intestinal mucus. Through proteomic analysis, we short-list potential protein candidates implicated in mucin assembly, thus paving the way for identifying the molecules responsible for the physiologically critical biophysical properties of mucus.
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Affiliation(s)
- Oliver W Meldrum
- ARC Centre of Excellence in Plant Cell Walls, The University of Queensland, St Lucia, 4072, Qld, Australia.,Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, 4072, Qld, Australia
| | - Gleb E Yakubov
- ARC Centre of Excellence in Plant Cell Walls, The University of Queensland, St Lucia, 4072, Qld, Australia. .,School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Qld, Australia.
| | - Mauricio R Bonilla
- ARC Centre of Excellence in Plant Cell Walls, The University of Queensland, St Lucia, 4072, Qld, Australia.,School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Qld, Australia
| | - Omkar Deshmukh
- School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Qld, Australia
| | - Michael A McGuckin
- Chronic Disease Biology and Care Program, Mater Research Institute - The University of Queensland, Translational Research Institute, Woolloongabba, QLD 4102, Australia
| | - Michael J Gidley
- ARC Centre of Excellence in Plant Cell Walls, The University of Queensland, St Lucia, 4072, Qld, Australia.,Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, 4072, Qld, Australia
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33
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Demouveaux B, Gouyer V, Gottrand F, Narita T, Desseyn JL. Gel-forming mucin interactome drives mucus viscoelasticity. Adv Colloid Interface Sci 2018; 252:69-82. [PMID: 29329667 DOI: 10.1016/j.cis.2017.12.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022]
Abstract
Mucus is a hydrogel that constitutes the first innate defense in all mammals. The main organic component of mucus, gel-forming mucins, forms a complex network through both reversible and irreversible interactions that drive mucus gel formation. Significant advances in the understanding of irreversible gel-forming mucins assembly have been made using recombinant protein approaches. However, little is known about the reversible interactions that may finely modulate mucus viscoelasticity, which can be characterized using rheology. This approach can be used to investigate both the nature of gel-forming mucins interactions and factors that influence hydrogel formation. This knowledge is directly relevant to the development of new drugs to modulate mucus viscoelasticity and to restore normal mucus functions in diseases such as in cystic fibrosis. The aim of the present review is to summarize the current knowledge about the relationship between the mucus protein matrix and its functions, with emphasis on mucus viscoelasticity.
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Affiliation(s)
| | - Valérie Gouyer
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Frédéric Gottrand
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Tetsuharu Narita
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France; Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Jean-Luc Desseyn
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France.
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34
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Bansil R, Turner BS. The biology of mucus: Composition, synthesis and organization. Adv Drug Deliv Rev 2018; 124:3-15. [PMID: 28970050 DOI: 10.1016/j.addr.2017.09.023] [Citation(s) in RCA: 326] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/24/2017] [Accepted: 09/27/2017] [Indexed: 02/06/2023]
Abstract
In this review we discuss mucus, the viscoelastic secretion from goblet or mucous producing cells that lines the epithelial surfaces of all organs exposed to the external world. Mucus is a complex aqueous fluid that owes its viscoelastic, lubricating and hydration properties to the glycoprotein mucin combined with electrolytes, lipids and other smaller proteins. Electron microscopy of mucosal surfaces reveals a highly convoluted surface with a network of fibers and pores of varying sizes. The major structural and functional component, mucin is a complex glycoprotein coded by about 20 mucin genes which produce a protein backbone having multiple tandem repeats of Serine, Threonine (ST repeats) where oligosaccharides are covalently O-linked. The N- and C-terminals of this apoprotein contain other domains with little or no glycosylation but rich in cysteines leading to dimerization and further multimerization via SS bonds. The synthesis of this complex protein starts in the endoplasmic reticulum with the formation of the apoprotein and is further modified via glycosylation in the cis and medial Golgi and packaged into mucin granules via Ca2+ bridging of the negative charges on the oligosaccharide brush in the trans Golgi. The mucin granules fuse with the plasma membrane of the secretory cells and following activation by signaling molecules release Ca2+ and undergo a dramatic change in volume due to hydration of the highly negatively charged polymer brush leading to exocytosis from the cells and forming the mucus layer. The rheological properties of mucus and its active component mucin and its mucoadhesivity are briefly discussed in light of their importance to mucosal drug delivery.
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35
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Quinton PM. Both Ways at Once: Keeping Small Airways Clean. Physiology (Bethesda) 2017; 32:380-390. [DOI: 10.1152/physiol.00013.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/07/2017] [Accepted: 07/07/2017] [Indexed: 12/13/2022] Open
Abstract
The small airways of the lungs are under constant assault from the pathogens and debris in the air that they must conduct to alveoli. Although hygiene is of paramount importance for respiratory health, the underlying principles of airway clearance have not been well integrated or established. Newly emerging concepts of simultaneous absorption and secretion of airway surface liquid (ASL) and the role of [Formula: see text] in the maturation of mucins have advanced from experimental evidence as well as observations from the congenital disease cystic fibrosis (CF) to present a novel model that integrates microanatomy with organ physiology to meet the constant challenge of cleaning small airways.
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36
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Brandolini L, d'Angelo M, Antonosante A, Villa S, Cristiano L, Castelli V, Benedetti E, Catanesi M, Aramini A, Luini A, Parashuraman S, Mayo E, Giordano A, Cimini A, Allegretti M. Differential protein modulation by ketoprofen and ibuprofen underlines different cellular response by gastric epithelium. J Cell Physiol 2017; 233:2304-2312. [DOI: 10.1002/jcp.26102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 07/14/2017] [Indexed: 01/14/2023]
Affiliation(s)
| | - Michele d'Angelo
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Andrea Antonosante
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Sara Villa
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Loredana Cristiano
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Vanessa Castelli
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Elisabetta Benedetti
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Mariano Catanesi
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Andrea Aramini
- Dompé Farmaceutici Spa; via Campo di Pile; L'Aquila Italy
| | - Alberto Luini
- Institute of Protein Biochemistry (IBP); National Research Council (CNR); Napoli Italy
| | | | - Emilia Mayo
- Institute of Protein Biochemistry (IBP); National Research Council (CNR); Napoli Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine; Department of Biology; Temple University; Philadelphia Pennsylvania
- Department of Medicine; Surgery and Neuroscience; University of Siena; Siena Italy
| | - Annamaria Cimini
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
- Sbarro Institute for Cancer Research and Molecular Medicine; Department of Biology; Temple University; Philadelphia Pennsylvania
- Gran Sasso National Laboratory (LNGS); National Institute for Nuclear Physics (INFN); Assergi Italy
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Lafforgue O, Bouguerra N, Poncet S, Seyssiecq I, Favier J, Elkoun S. Thermo-physical properties of synthetic mucus for the study of airway clearance. J Biomed Mater Res A 2017; 105:3025-3033. [PMID: 28758330 DOI: 10.1002/jbm.a.36161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 05/24/2017] [Accepted: 07/24/2017] [Indexed: 11/09/2022]
Abstract
In this article, dynamic viscosity, surface tension, density, heat capacity and thermal conductivity, of a bronchial mucus simulant proposed by Zahm et al., Eur Respir J 1991; 4: 311-315 were experiementally determined. This simulant is mainly composed of a galactomannan gum and a scleroglucan. It was shown that thermophysical properties of synthetic mucus are dependant of scleroglucan concentrations. More importantly and for some scleroglucan concentrations, the syntetic mucus, exhibits, somehow, comparable thermophysical properties to real bronchial mucus. An insight on the microstructure of this simulant is proposed and the different properties enounced previously have been measured for various scleroglucan concentrations and over a certain range of operating temperatures. This synthetic mucus is found to mimic well the rheological behavior and the surface tension of real mucus for different pathologies. Density and thermal properties have been measured for the first time. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3025-3033, 2017.
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Affiliation(s)
- O Lafforgue
- Aix-Marseille Université, CNRS, Ecole Centrale de Marseille, Laboratoire M2P2 UMR 7340, 38 rue F. Joliot-Curie, Technopôle de Château-Gombert, Marseille, 13451, France
| | - N Bouguerra
- Université de Sherbrooke, Faculté de génie, Département de génie mécanique, 2500 Boulevard de l'Université, Sherbrooke, QC, J1K 2R1, Canada
| | - S Poncet
- Aix-Marseille Université, CNRS, Ecole Centrale de Marseille, Laboratoire M2P2 UMR 7340, 38 rue F. Joliot-Curie, Technopôle de Château-Gombert, Marseille, 13451, France.,Université de Sherbrooke, Faculté de génie, Département de génie mécanique, 2500 Boulevard de l'Université, Sherbrooke, QC, J1K 2R1, Canada
| | - I Seyssiecq
- Aix-Marseille Université, CNRS, Ecole Centrale de Marseille, Laboratoire M2P2 UMR 7340, 38 rue F. Joliot-Curie, Technopôle de Château-Gombert, Marseille, 13451, France
| | - J Favier
- Aix-Marseille Université, CNRS, Ecole Centrale de Marseille, Laboratoire M2P2 UMR 7340, 38 rue F. Joliot-Curie, Technopôle de Château-Gombert, Marseille, 13451, France
| | - S Elkoun
- Université de Sherbrooke, Faculté de génie, Département de génie mécanique, 2500 Boulevard de l'Université, Sherbrooke, QC, J1K 2R1, Canada
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38
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Böni LJ, Zurflüh R, Widmer M, Fischer P, Windhab EJ, Rühs PA, Kuster S. Hagfish slime exudate stabilization and its effect on slime formation and functionality. Biol Open 2017; 6:1115-1122. [PMID: 28619721 PMCID: PMC5550916 DOI: 10.1242/bio.025528] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/02/2017] [Indexed: 01/16/2023] Open
Abstract
Hagfish produce vast amounts of slime when under attack. The slime is the most dilute hydrogel known to date, and is a highly interesting material for biomaterial research. It forms from a glandular secrete, called exudate, which deploys upon contact with seawater. To study slime formation ex vivo and to characterize its material properties, stabilization of the sensitive slime exudate is crucial. In this study, we compared the two main stabilization methods, dispersion in high osmolarity citrate/PIPES (CP) buffer and immersion in oil, and tested the influence of time, temperature and pH on the stability of the exudate and functionality of the slime. Using water retention measurements to assess slime functionality, we found that CP buffer and oil preserved the exudate within the first 5 hours without loss of functionality. For longer storage times, slime functionality decreased for both stabilization methods, for which the breakdown mechanisms differed. Stabilization in oil likely favored temperature-sensitive osmotic-driven swelling and rupture of the mucin vesicles, causing the exudate to gel and clump. Extended storage in CP buffer resulted in an inhibited unraveling of skeins. We suggest that a water soluble protein glue, which mediates skein unraveling in functional skeins, denatures and gradually becomes insoluble during storage in CP buffer. The breakdown was accentuated when the pH of the CP buffer was raised from pH 6.7 to pH 8.5, probably caused by increased denaturation of the protein glue or by inferior vesicle stabilization. However, when fresh exudate was mixed into seawater or phosphate buffer at pH 6-9, slime functionality was not affected, showing pH insensitivity of the slime formation around a neutral pH. These insights on hagfish exudate stabilization mechanisms will support hagfish slime research at a fundamental level, and contribute to resolve the complex mechanisms of skein unraveling and slime formation.
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Affiliation(s)
- L J Böni
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - R Zurflüh
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - M Widmer
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - P Fischer
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - E J Windhab
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
| | - P A Rühs
- Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - S Kuster
- Department of Health Science and Technology, ETH Zürich, 8092 Zürich, Switzerland
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39
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Gel-forming mucins form distinct morphologic structures in airways. Proc Natl Acad Sci U S A 2017; 114:6842-6847. [PMID: 28607090 PMCID: PMC5495256 DOI: 10.1073/pnas.1703228114] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gel-forming mucins, the primary macromolecular components of airway mucus, facilitate airway clearance by mucociliary transport. In cystic fibrosis (CF) altered mucus properties impair mucociliary transport. Airways primarily secrete two closely related gel-forming mucins, MUC5B and MUC5AC. However, their morphologic structures and associations in airways that contain abundant submucosal glands and goblet cells are uncertain. Moreover, there is limited knowledge about mucins in airways not affected by inflammation, infection, or remodeling or in CF airways. Therefore, we examined airways freshly excised from newborn non-CF pigs and CF pigs before secondary manifestations develop. We found that porcine submucosal glands produce MUC5B, whereas goblet cells produce predominantly MUC5AC plus some MUC5B. We found that MUC5B emerged from submucosal gland ducts in the form of strands composed of multiple MUC5B filaments. In contrast, MUC5AC emerged from goblet cells as wispy threads and sometimes formed mucin sheets. In addition, MUC5AC often partially coated the MUC5B strands. Compared with non-CF, MUC5B more often filled CF submucosal gland ducts. MUC5AC sheets also accumulated in CF airways overlying MUC5B strands. These results reveal distinct morphology and interactions for MUC5B and MUC5AC and suggest that the two mucins make distinct contributions to mucociliary transport. Thus, they provide a framework for understanding abnormalities in disease.
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40
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Abdullah LH, Evans JR, Wang TT, Ford AA, Makhov AM, Nguyen K, Coakley RD, Griffith JD, Davis CW, Ballard ST, Kesimer M. Defective postsecretory maturation of MUC5B mucin in cystic fibrosis airways. JCI Insight 2017; 2:e89752. [PMID: 28352653 DOI: 10.1172/jci.insight.89752] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In cystic fibrosis (CF), airway mucus becomes thick and viscous, and its clearance from the airways is impaired. The gel-forming mucins undergo an ordered "unpacking/maturation" process after granular release that requires an optimum postsecretory environment, including hydration and pH. We hypothesized that this unpacking process is compromised in the CF lung due to abnormal transepithelial fluid transport that reduces airway surface hydration and alters ionic composition. Using human tracheobronchial epithelial cells derived from non-CF and CF donors and mucus samples from human subjects and domestic pigs, we investigated the process of postsecretory mucin unfolding/maturation, how these processes are defective in CF airways, and the probable mechanism underlying defective unfolding. First, we found that mucins released into a normal lung environment transform from a compact granular form to a linear form. Second, we demonstrated that this maturation process is defective in the CF airway environment. Finally, we demonstrated that independent of HCO3- and pH levels, airway surface dehydration was the major determinant of this abnormal unfolding process. This defective unfolding/maturation process after granular release suggests that the CF extracellular environment is ion/water depleted and likely contributes to abnormal mucus properties in CF airways prior to infection and inflammation.
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Affiliation(s)
- Lubna H Abdullah
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Jessica R Evans
- Department of Physiology and Biophysics, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - T Tiffany Wang
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Amina A Ford
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Alexander M Makhov
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Kristine Nguyen
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Raymond D Coakley
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Jack D Griffith
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - C William Davis
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Stephen T Ballard
- Department of Physiology and Biophysics, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Mehmet Kesimer
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, USA
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41
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Chairatana P, Nolan EM. Defensins, lectins, mucins, and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut. Crit Rev Biochem Mol Biol 2017; 52:45-56. [PMID: 27841019 PMCID: PMC5233583 DOI: 10.1080/10409238.2016.1243654] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/19/2016] [Accepted: 09/28/2016] [Indexed: 02/08/2023]
Abstract
In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors - enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A - that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.
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Affiliation(s)
- Phoom Chairatana
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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42
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Corfield A. Eukaryotic protein glycosylation: a primer for histochemists and cell biologists. Histochem Cell Biol 2017; 147:119-147. [PMID: 28012131 PMCID: PMC5306191 DOI: 10.1007/s00418-016-1526-4] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2016] [Indexed: 12/21/2022]
Abstract
Proteins undergo co- and posttranslational modifications, and their glycosylation is the most frequent and structurally variegated type. Histochemically, the detection of glycan presence has first been performed by stains. The availability of carbohydrate-specific tools (lectins, monoclonal antibodies) has revolutionized glycophenotyping, allowing monitoring of distinct structures. The different types of protein glycosylation in Eukaryotes are described. Following this educational survey, examples where known biological function is related to the glycan structures carried by proteins are given. In particular, mucins and their glycosylation patterns are considered as instructive proof-of-principle case. The tissue and cellular location of glycoprotein biosynthesis and metabolism is reviewed, with attention to new findings in goblet cells. Finally, protein glycosylation in disease is documented, with selected examples, where aberrant glycan expression impacts on normal function to let disease pathology become manifest. The histological applications adopted in these studies are emphasized throughout the text.
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Affiliation(s)
- Anthony Corfield
- Mucin Research Group, School of Clinical Sciences, Bristol Royal Infirmary, University of Bristol, Bristol, BS2 8HW, UK.
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43
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The innate immune properties of airway mucosal surfaces are regulated by dynamic interactions between mucins and interacting proteins: the mucin interactome. Mucosal Immunol 2016; 9:1442-1454. [PMID: 27072609 PMCID: PMC5063652 DOI: 10.1038/mi.2016.27] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 03/01/2016] [Indexed: 02/04/2023]
Abstract
Chronic lung diseases such as cystic fibrosis, chronic bronchitis, and asthma are characterized by hypersecretion and poor clearance of mucus, which are associated with poor prognosis and mortality. Little is known about the relationship between the biophysical properties of mucus and its molecular composition. The mucins MUC5B and MUC5AC are traditionally believed to generate the characteristic biophysical properties of airway mucus. However, the contribution of hundreds of globular proteins to the biophysical properties of mucus is not clear. Approximately one-third of the total mucus proteome comprises distinct, multi-protein complexes centered around airway mucins. These complexes constitute a discrete entity we call the "mucin interactome". The data suggest that while the majority of these proteins interact with mucins via electrostatic and weak interactions, some interact through very strong hydrophobic and/or covalent interactions. Using reagents that interfere with protein-protein interactions, the complexes can be disassembled, and mucus rheology can be dramatically altered. Using MUC5B-glutathione S-transferase (GST) and MUC5B-galectin-3 as a representative of these interactions, we provide evidence that individual mucin protein interactions can alter the biophysical properties of mucus and modulate the biological function of the protein. We propose that the key mechano- and bio-active functions of mucus depend on the dynamic interactions between mucins and globular proteins. These observations challenge the paradigm that mucins are the only molecules that confer biophysical properties of mucus. These observations may ultimately lead to a greater understanding of the system and guide the development of strategies for more effective interventions using better therapeutic agents.
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44
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Abstract
Colonic mucus is a key biological hydrogel that protects the gut from infection and physical damage and mediates host-microbe interactions and drug delivery. However, little is known about how its structure is influenced by materials it comes into contact with regularly. For example, the gut abounds in polymers such as dietary fibers or administered therapeutics, yet whether such polymers interact with the mucus hydrogel, and if so, how, remains unclear. Although several biological processes have been identified as potential regulators of mucus structure, the polymeric composition of the gut environment has been ignored. Here, we demonstrate that gut polymers do in fact regulate mucus hydrogel structure, and that polymer-mucus interactions can be described using a thermodynamic model based on Flory-Huggins solution theory. We found that both dietary and therapeutic polymers dramatically compressed murine colonic mucus ex vivo and in vivo. This behavior depended strongly on both polymer concentration and molecular weight, in agreement with the predictions of our thermodynamic model. Moreover, exposure to polymer-rich luminal fluid from germ-free mice strongly compressed the mucus hydrogel, whereas exposure to luminal fluid from specific-pathogen-free mice-whose microbiota degrade gut polymers-did not; this suggests that gut microbes modulate mucus structure by degrading polymers. These findings highlight the role of mucus as a responsive biomaterial, and reveal a mechanism of mucus restructuring that must be integrated into the design and interpretation of studies involving therapeutic polymers, dietary fibers, and fiber-degrading gut microbes.
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45
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Georgiades P, di Cola E, Heenan RK, Pudney PDA, Thornton DJ, Waigh TA. A combined small-angle X-ray and neutron scattering study of the structure of purified soluble gastrointestinal mucins. Biopolymers 2016; 101:1154-64. [PMID: 25041765 PMCID: PMC4654235 DOI: 10.1002/bip.22523] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 07/02/2014] [Indexed: 11/10/2022]
Abstract
The structures of purified soluble porcine gastric (Muc5ac) and duodenal (Muc2) mucin solutions at neutral and acidic pH were examined using small-angle X-ray scattering and small-angle neutron scattering experiments. We provide evidence for the morphology of the network above the semidilute overlap concentration and above the entanglement concentration. Furthermore, we investigated the gelation of both types of mucin solutions in response to a reduction in pH, where we observed the formation of large-scale heterogeneities within the polymer solutions, typical of microphase-separated gels. The concentration dependence of the inhomogeneity length scale (Ξ) and the amplitude of the excess scattering intensity [I(ex) (0)] are consistent with previously studied gelled synthetic polymeric systems. The persistence lengths of the chains were found to be similar for both Muc5ac and Muc2 from Kratky plots of the neutron data (8 ± 2 nm).
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Affiliation(s)
- Pantelis Georgiades
- Biological Physics, Department of Physics and Astronomy, University of Manchester, Manchester, M60 1QD, UK; Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
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Karaulov AV, Gurina NN, Novikov DV, Fomina SG, Novikov VV. [Role of MUC1 Expression in Tumor Progression]. ACTA ACUST UNITED AC 2016; 71:392-6. [PMID: 29297994 DOI: 10.15690/vramn736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mucin 1 (MUC1) is a multistructural and multifunctional protein that is involved in regulating diverse cellular activities. This strongly glycosylated transmembrane protein forms a mucous gel on the surface of epithelial cells that protects the cells from injury. MUC1 acts as a signaling molecule and transcription factor modulating metabolism and resistance to bacterial-induced inflammation. This article presents a review of the relationship between structural and functional changes of the MUC1 and the characteristics of cancer cells. The alteration in MUC1 expression level, a number of structural forms, protein glycosylation and localization occurs in cancer cells. These alterations lead to metabolic reprogramming associated with proliferation, resistance to hypoxia and angiogenesis which affects the survival of cancer cells. Furthermore, cancer cells can take advantage of MUC1 interaction with adhesion molecules for invasion and metastasis. Thus, MUC1 plays a key role both in the homeostasis of epithelial cells and in cancer progression. Understanding the role of MUC1 expression in tumor cells survival is important for the development of new monitoring and therapeutic approaches for the treatment MUC1 positive maligancies.
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Gianotti A, Capurro V, Scudieri P, Galietta LJV, Moran O, Zegarra-Moran O. Pharmacological rescue of mutant CFTR protein improves the viscoelastic properties of CF mucus. J Cyst Fibros 2015; 15:295-301. [PMID: 26677762 DOI: 10.1016/j.jcf.2015.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND In CF patients, the defective ion transport causes a simultaneous reduction of fluid, Cl(-) and HCO3(-) secretion. We aimed to demonstrate that the resulting altered properties of mucus can be recovered using lumacaftor, a CFTR corrector. METHODS The micro-rheology of non-CF and CF mucus was analysed using Multiple Particle Tracking. RESULTS The diffusion coefficient of nano-beads imbedded in mucus from CF human bronchial epithelium was lower than in non-CF mucus, and the elastic and viscous moduli were higher. We found that 25% correction of F508del-CFTR mutation with lumacaftor was enough to improve significantly CF mucus properties. Surprisingly, also incubation with amiloride, a compound that reduces fluid absorption but might not change the secretion of HCO3(-) towards the airway surface fluid, improved CF mucus properties. CONCLUSION CF mucus properties can be recovered by either improving the hydration of the airways or recovering Cl(-) and HCO3(-) secretion across the mutated protein treated with a corrector compound.
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Affiliation(s)
- Ambra Gianotti
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, via Gaslini, 5, 16148 Genoa, Italy
| | - Valeria Capurro
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, via Gaslini, 5, 16148 Genoa, Italy
| | - Paolo Scudieri
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, via Gaslini, 5, 16148 Genoa, Italy
| | - Luis J V Galietta
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, via Gaslini, 5, 16148 Genoa, Italy
| | - Oscar Moran
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via de Marini, 6, 16149 Genoa, Italy
| | - Olga Zegarra-Moran
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, via Gaslini, 5, 16148 Genoa, Italy.
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Hoffmann W. TFF2, a MUC6-binding lectin stabilizing the gastric mucus barrier and more (Review). Int J Oncol 2015. [PMID: 26201258 DOI: 10.3892/ijo.2015.3090] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The peptide TFF2 (formerly 'spasmolytic polypeptide'), a member of the trefoil factor family (TFF) containing two TFF domains, is mainly expressed together with the mucin MUC6 in the gastric epithelium and duodenal Brunner's glands. Pathologically, TFF2 expression is observed ectopically during stone diseases, chronic inflammatory conditions and in several metaplastic and neoplastic epithelia; most prominent being the 'spasmolytic polypeptide-expressing metaplasia' (SPEM), which is an established gastric precancerous lesion. TFF2 plays a critical role in maintaining gastric mucosal integrity and appears to restrain tumorigenesis in the stomach. Recently, porcine TFF2 has been shown to interact with the gastric mucin MUC6 and thus stabilize the gastric mucus barrier. On the one hand, TFF2 binds to MUC6 via non-covalent lectin interactions with the glycotope GlcNAcα1→4Galβ1→R. On the other hand, TFF2 is probably also covalently bound to MUC6 via disulfide bridges. Thus, implications for the complex multimeric assembly, cross-linking, and packaging of MUC6 as well as the rheology of gastric mucus are discussed in detail in this review. Furthermore, TFF2 is also expressed in minor amounts in the immune and nervous systems. Thus, similar to galectins, its lectin activity would perfectly enable TFF2 to form multivalent complexes and cross-linked lattices with a plethora of transmembrane glycoproteins and thus modulate different signal transduction processes. This could explain the multiple and diverse biological effects of TFF2 [e.g., motogenic, (anti)apoptotic, and angiogenic effects]. Finally, a function during fertilization is also possible for TFF domains because they occur as shuffled modules in certain zona pellucida proteins.
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Affiliation(s)
- Werner Hoffmann
- Institute of Molecular Biology and Medicinal Chemistry, Otto-von-Guericke-University Magdeburg, D-39120 Magdeburg, Germany
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Ismail N, Giribabu N, Muniandy S, Salleh N. Estrogen and progesterone differentially regulate the levels of cystic fibrosis transmembrane regulator (CFTR), adenylate cyclase (AC), and cyclic adenosine mono-phosphate (cAMP) in the rat cervix. Mol Reprod Dev 2015; 82:463-74. [PMID: 26018621 DOI: 10.1002/mrd.22496] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/15/2015] [Indexed: 12/14/2022]
Abstract
The consistency of the cervical mucus changes with the reproductive cycle, which we hypothesized involved changing levels of cystic fibrosis transmembrane regulator (CFTR), adenylate cyclase (AC), and cyclic adenosine mono-phosphate (cAMP). We therefore measured the abundance of each in the rat cervix under estrogen and progesterone influence to determine if the activity of these components could explain the changes in the consistency of cervical mucus. Ovariectomised adult female rats were treated with three days of either estrogen (1 μg/kg/day) or progesterone (20 mg/kg/day), or three days of estrogen followed by two days of either vehicle or progesterone or estrogen plus progesterone. In some groups, mifepristone (7 mg/kg/day) was concurrently given with progesterone. Animals were then sacrificed, and the cervix was harvested for protein and mRNA expression analyses by Western blot and real-time PCR, respectively. The distribution of proteins was investigated by immunohistochemistry, and levels of cAMP were determined by enzyme-linked immunosorbent assay (ELISA). Cftr mRNA, AC protein, and cAMP levels in cervical homogenates as well as the tissue distribution of CFTR and AC in endocervical epithelia were highest under estrogen influence; the opposite pattern was seen under progesterone influence. Cervical lumen circumference was highest under estrogen and lowest under progesterone. The effects of progesterone were antagonized by mifepristone. Therefore, increased abundance of CFTR, AC, and cAMP under estrogen influence could account for the increased fluid accumulation within the cervical lumen, which would contribute to lower cervical mucus consistency, whereas progesterone reverses this effect at the molecular and organ level.
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Affiliation(s)
- Nurain Ismail
- Department of Physiology, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Nelli Giribabu
- Department of Physiology, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Sekaran Muniandy
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Naguib Salleh
- Department of Physiology, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia
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SNAP23 is selectively expressed in airway secretory cells and mediates baseline and stimulated mucin secretion. Biosci Rep 2015; 35:BSR20150004. [PMID: 26182382 PMCID: PMC4613665 DOI: 10.1042/bsr20150004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/14/2015] [Indexed: 11/17/2022] Open
Abstract
Airway mucin secretion is important pathophysiologically and as a model of polarized epithelial regulated exocytosis. We find the trafficking protein, SNAP23 (23-kDa paralogue of synaptosome-associated protein of 25 kDa), selectively expressed in secretory cells compared with ciliated and basal cells of airway epithelium by immunohistochemistry and FACS, suggesting that SNAP23 functions in regulated but not constitutive epithelial secretion. Heterozygous SNAP23 deletant mutant mice show spontaneous accumulation of intracellular mucin, indicating a defect in baseline secretion. However mucins are released from perfused tracheas of mutant and wild-type (WT) mice at the same rate, suggesting that increased intracellular stores balance reduced release efficiency to yield a fully compensated baseline steady state. In contrast, acute stimulated release of intracellular mucin from mutant mice is impaired whether measured by a static imaging assay 5 min after exposure to the secretagogue ATP or by kinetic analysis of mucins released from perfused tracheas during the first 10 min of ATP exposure. Together, these data indicate that increased intracellular stores cannot fully compensate for the defect in release efficiency during intense stimulation. The lungs of mutant mice develop normally and clear bacteria and instilled polystyrene beads comparable to WT mice, consistent with these functions depending on baseline secretion that is fully compensated.
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