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.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL108808-03
Application #
8686928
Study Section
Special Emphasis Panel (ZHL1-CSR-Q)
Project Start
Project End
Budget Start
2014-06-01
Budget End
2015-05-31
Support Year
3
Fiscal Year
2014
Total Cost
$374,451
Indirect Cost
$121,651
Name
University of North Carolina Chapel Hill
Department
Type
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Pandiyarajan, C K; Rubinstein, Michael; Genzer, Jan (2016) Surface-Anchored Poly(N-isopropylacrylamide) Orthogonal Gradient Networks. Macromolecules 49:5076-5083
Sesma, Juliana I; Weitzer, Clarissa D; Livraghi-Butrico, Alessandra et al. (2016) UDP-glucose promotes neutrophil recruitment in the lung. Purinergic Signal 12:627-635
Livraghi-Butrico, A; Grubb, B R; Wilkinson, K J et al. (2016) Contribution of mucus concentration and secreted mucins Muc5ac and Muc5b to the pathogenesis of muco-obstructive lung disease. Mucosal Immunol :
Leuty, Gary M; Tsige, Mesfin; Grest, Gary S et al. (2016) Tension Amplification in Tethered Layers of Bottle-Brush Polymers. Macromolecules 49:1950-1960
Baeza, Guilhem P; Dessi, Claudia; Costanzo, Salvatore et al. (2016) Network dynamics in nanofilled polymers. Nat Commun 7:11368
Button, Brian; Anderson, Wayne H; Boucher, Richard C (2016) Mucus Hyperconcentration as a Unifying Aspect of the Chronic Bronchitic Phenotype. Ann Am Thorac Soc 13 Suppl 2:S156-62
Yu, Dongfang; Davis, Richard M; Aita, Megumi et al. (2016) Characterization of Rat Meibomian Gland Ion and Fluid Transport. Invest Ophthalmol Vis Sci 57:2328-43
Choueiri, Rachelle M; Galati, Elizabeth; Thérien-Aubin, Héloïse et al. (2016) Surface patterning of nanoparticles with polymer patches. Nature 538:79-83
Ramsey, Kathryn A; Rushton, Zachary L; Ehre, Camille (2016) Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins. J Vis Exp :
Bennett, William D; Henderson, Ashley G; Donaldson, Scott H (2016) Hydrator Therapies for Chronic Bronchitis. Lessons from Cystic Fibrosis. Ann Am Thorac Soc 13 Suppl 2:S186-90

Showing the most recent 10 out of 65 publications