Pathologic mucus is a major problem in asthma exacerbations, contributing significantly to mechanisms of airflow obstruction, and playing a major role in death from asthma. Despite this important role for mucus in asthma exacerbations, the mechanism underlying the formation of rubbery occlusive mucus in asthma have been poorly understood, and mucolytic therapies are limited in number, efficacy, and tolerability. Recently, the Fahy lab has shown that excessive numbers of mucin disulfide bonds represent a therapeutic target in pathologic mucus gels. In addition, the lab has shown that disulfide bonds can be broken with reducing agents such as N-acetyl cysteine (NAC). Because of the significant limitations of NAC as a therapeutic, we have collaborated with the Oscarson lab at University College Dublin to explore the utility of reducing agents using thiol-modified saccharides (thiol-saccharides). The rationale behind choosing a carbohydrate scaffold is that they are polar, cheap, natural, often crystalline, and, with their abundance of hydroxyl groups as well as chiral centers, offer easy access to analogues for structure activity relationship (SAR) studies. Preliminary data show high mucolytic efficacy for a candidate thiol-saccharides with multiple advantages over NAC, including faster onset of action and better potency. We propose three Aims to advance understanding of mucus pathology in acute severe asthma and to hasten a new drug development program for thiol-saccharides as a novel mucolytic treatment for mucus pathology in acute asthma.
Aim 1 will explore the role of oxidative stress as a mechanism of mucus pathology in acute severe asthma.
Aim 2 will synthesize a library of thiol-saccharides and evaluate their physicochemical properties, aerosolization characteristics, and stability as spray dried compounds with the goal to optimize formulation of their delivery as a dry powder.
Aim 3 will test whether thiol- saccharides can effectively liquefy mucus in acute severe asthma.

Public Health Relevance

Asthma exacerbations are a major public health problem, and mucus contributes significantly to the pathogens of asthma exacerbations. Available mucolytics have significant limitations of cost and convenience that restrict their application in practice. Or project proposes to address an unmet need for a well-tolerated and easily delivered mucolytic drug whose target of disulfide linkages make it relevant to diseases associated with heightened oxidative stress, including acute severe asthma.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL080414-10
Application #
9295050
Study Section
Lung Cellular, Molecular, and Immunobiology Study Section (LCMI)
Program Officer
Noel, Patricia
Project Start
2005-07-01
Project End
2020-04-30
Budget Start
2017-05-01
Budget End
2018-04-30
Support Year
10
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94118
Lachowicz-Scroggins, Marrah E; Gordon, Erin D; Wesolowska-Andersen, Agata et al. (2018) Cadherin-26 (CDH26) regulates airway epithelial cell cytoskeletal structure and polarity. Cell Discov 4:7
Wong-McGrath, Kelly; Denlinger, Loren C; Bleecker, Eugene R et al. (2018) Internet-Based Monitoring in the Severe Asthma Research Program Identifies a Subgroup of Patients With Labile Asthma Control. Chest 153:378-386
Dunican, Eleanor M; Elicker, Brett M; Gierada, David S et al. (2018) Mucus plugs in patients with asthma linked to eosinophilia and airflow obstruction. J Clin Invest 128:997-1009
MacNee, William; Fahy, John V; Nicod, Laurent P et al. (2017) Purpose of the Conference: The 2017 Transatlantic Conference on Lung Diseases. Ann Am Thorac Soc 14:S313
Gordon, Erin D; Simpson, Laura J; Rios, Cydney L et al. (2016) Alternative splicing of interleukin-33 and type 2 inflammation in asthma. Proc Natl Acad Sci U S A 113:8765-70
Kerr, Sheena C; Fischer, Gregory J; Sinha, Meenal et al. (2016) FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection. PLoS Pathog 12:e1005555
Lachowicz-Scroggins, Marrah E; Yuan, Shaopeng; Kerr, Sheena C et al. (2016) Abnormalities in MUC5AC and MUC5B Protein in Airway Mucus in Asthma. Am J Respir Crit Care Med 194:1296-1299
Peters, Michael C; McGrath, Kelly Wong; Hawkins, Gregory A et al. (2016) Plasma interleukin-6 concentrations, metabolic dysfunction, and asthma severity: a cross-sectional analysis of two cohorts. Lancet Respir Med 4:574-584
Fahy, John V (2016) Asthma Was Talking, But We Weren't Listening. Missed or Ignored Signals That Have Slowed Treatment Progress. Ann Am Thorac Soc 13 Suppl 1:S78-82
MacNee, William; Fahy, John V; Nicod, Laurent P et al. (2016) Purpose of the Conference: 2016 Transatlantic Airway Conference. Ann Am Thorac Soc 13 Suppl 5:S395

Showing the most recent 10 out of 35 publications