Patients with cystic fibrosis (CF) and chronic bronchitis, i.e. COPD, exhibit a significantly reduced mucus clearance. The overarching goal of this project is to test the hypothesis that reduced rates of mucociliary and cough clearance in these patients are related to mucus dehydration and the resulting increased adhesion of mucus to cells as well as increased mucus cohesion strength. Both CF and COPD subjects exhibit an increase in ainvay mucus concentration, reflecting: 1) reduced ainway surface solvent (salt/water), e.g., as observed with CFTR dysfunction;2) mucin hypersecretion, as observed with goblet cell hyperplasia;or 3) a combination of the two. Based on our recent theoretical and experimental data, we have developed a novel model, referred to as the """"""""two-gel"""""""" model, that suggests that in addition to a mucus gel, ain/vays exhibit a """"""""periciliary"""""""" layer (PCL), which is also a gel formed by tethered mucins (MUC1, MUC4, and MUC16). Efficient clearance requires hydration of the PCL that is sustained as long as its osmotic pressure is higher than that of the mucus gel layer. Importantly, the osmotic pressure of the mucus layer is largely determined by the concentration of the secreted mucins MUC5AC and MUC5B. To test our two-gel hypothesis, we have developed novel techniques to measure mucus osmotic pressure, adhesion/cohesion strength, viscosity, and elastic modulus and to determine the effect of these physical properties on mucus transport rate for both normal and CF cultures. We propose that reducing mucus concentration, cohesion strength, and mucus adhesion to epithelial cells will restore effective mucus clearance and thus benefit both CF and COPD patients. The novel approach to physical processes in airway surface layer will allow us to identify the optimal combination of rehydration and pharmacological agents to restore/accelerate the rate of mucus clearance. The identified agents that reduce the adhesion/cohesion strength and restore normal mucus clearance will be tested in mouse models of obstructive lung disease (Project II) and in COPD patients (Projects III).

Public Health Relevance

This project focus on the developments and validation of new physical models of airway surface layer and the role of mucus hydration, adhesion and cohesion in controlling mucus clearance. These new ideas lead to systematic developments of new drugs aimed at restoring and maintaining mucus clearance in patients with obstructive lung diseases.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Program Projects (P01)
Project #
Application #
Study Section
Special Emphasis Panel (ZHL1-CSR-Q)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of North Carolina Chapel Hill
Chapel Hill
United States
Zip Code
Abdullah, Lubna H; Coakley, Raymond; Webster, Megan J et al. (2018) Mucin Production and Hydration Responses to Mucopurulent Materials in Normal versus Cystic Fibrosis Airway Epithelia. Am J Respir Crit Care Med 197:481-491
Yu, Dongfang; Saini, Yogesh; Chen, Gang et al. (2018) Loss of ? Epithelial Sodium Channel Function in Meibomian Glands Produces Pseudohypoaldosteronism 1-Like Ocular Disease in Mice. Am J Pathol 188:95-110
Muhlebach, Marianne S; Hatch, Joseph E; Einarsson, Gisli G et al. (2018) Anaerobic bacteria cultured from cystic fibrosis airways correlate to milder disease: a multisite study. Eur Respir J 52:
Livraghi-Butrico, Alessandra; Wilkinson, Kristen J; Volmer, Allison S et al. (2018) Lung disease phenotypes caused by overexpression of combinations of ?-, ?-, and ?-subunits of the epithelial sodium channel in mouse airways. Am J Physiol Lung Cell Mol Physiol 314:L318-L331
Chen, Gang; Volmer, Allison S; Wilkinson, Kristen J et al. (2018) Role of Spdef in the Regulation of Muc5b Expression in the Airways of Naive and Mucoobstructed Mice. Am J Respir Cell Mol Biol 59:383-396
Bennett, William D; Zeman, Kirby L; Laube, Beth L et al. (2018) Homogeneity of Aerosol Deposition and Mucociliary Clearance are Improved Following Ivacaftor Treatment in Cystic Fibrosis. J Aerosol Med Pulm Drug Deliv 31:204-211
Ge, Ting; Grest, Gary S; Rubinstein, Michael (2018) Nanorheology of Entangled Polymer Melts. Phys Rev Lett 120:057801
Reighard, Katelyn P; Ehre, Camille; Rushton, Zachary L et al. (2017) Role of Nitric Oxide-Releasing Chitosan Oligosaccharides on Mucus Viscoelasticity. ACS Biomater Sci Eng 3:1017-1026
Zhou, Jinsheng; Wang, Yanqian; Menard, Laurent D et al. (2017) Enhanced nanochannel translocation and localization of genomic DNA molecules using three-dimensional nanofunnels. Nat Commun 8:807
Livraghi-Butrico, A; Grubb, B R; Wilkinson, K J et al. (2017) Contribution of mucus concentration and secreted mucins Muc5ac and Muc5b to the pathogenesis of muco-obstructive lung disease. Mucosal Immunol 10:829

Showing the most recent 10 out of 76 publications