Fatal episodes of asthma are associated with profound mucus hypersecretion and mucus plugging of the airways. Despite the association of mucus hypersecretion with the morbidity and mortality of asthma, the mechanisms governing the abnormal production of mucus remain elusive. Recently, we and others have shown that the Th2 cytokine, IL-13, is an important regulator of mucus cell metaplasia and asthma pathogenesis. However, the exact mechanisms by which IL-13 regulates mucus production are not known. The overall goal of this proposal is to define the molecular mechanisms underlying IL-13- induced goblet cell metaplasia (GCM). Our preliminary data suggest that IL-13 induces goblet cell metaplasia and mucus secretion via direct actions on the airway epithelium. Furthermore, a preliminary query of IL-13-induced gene expression patterns suggests that IL-13-induced GCM is associated with the upregulation of epidermal growth factor receptor signaling pathways and the expression of a newly described Ca activated chloride channel. Thus, we hypothesize that IL-13 induces GCM through the coordinate regulation of EGFR signaling pathways and Ca activated chloride channel activity. To test this hypothesis, we propose the following specific aims: 1) to define the exact sequence of events induced by IL-13 in primary murine and human epithelial cells; 2) to determine the role of EGFR signaling pathways in IL-13-induced mucus cell changes; 3) to determine the role that the newly described family of Ca activated chloride channels plays in regulating mucus cell differentiation and mucus release; and 4) to determine the relationship between IL-13-mediated pathways and mucus hypersecretion in human asthma. A better understanding of the mechanisms underlying IL-13-induced mucus hypersecretion should guide the development of novel strategies for the treatment of asthma and other hypersecretory diseases of the lung.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL072987-03
Application #
6931071
Study Section
Special Emphasis Panel (ZHL1-CSR-P (F1))
Program Officer
Banks-Schlegel, Susan P
Project Start
2003-08-06
Project End
2007-07-31
Budget Start
2005-08-01
Budget End
2006-07-31
Support Year
3
Fiscal Year
2005
Total Cost
$372,500
Indirect Cost
Name
Children's Hospital Med Ctr (Cincinnati)
Department
Type
DUNS #
071284913
City
Cincinnati
State
OH
Country
United States
Zip Code
45229
Perkins, Charles; Wills-Karp, Marsha; Finkelman, Fred D (2006) IL-4 induces IL-13-independent allergic airway inflammation. J Allergy Clin Immunol 118:410-9
Finkelman, Fred D; Yang, Mingyan; Perkins, Charles et al. (2005) Suppressive effect of IL-4 on IL-13-induced genes in mouse lung. J Immunol 174:4630-8
Guajardo, Jesus R; Schleifer, Kathleen W; Daines, Michael O et al. (2005) Altered gene expression profiles in nasal respiratory epithelium reflect stable versus acute childhood asthma. J Allergy Clin Immunol 115:243-51
Wills-Karp, Marsha (2004) Interleukin-13 in asthma pathogenesis. Immunol Rev 202:175-90