Idiopathic pulmonary fibrosis (IPF) is a disease characterized by progressive scarring of the lungs resulting in deterioration in lung function with a median survival of 3.5 years. Pulmonary fibrosis is thought to be a disorder of abnormal wound healing, wherein the initial trigger to the fibrotic response is injury to the alveolar epithelium, followed by an exuberant, non-resolving wound-healing response. TGF-? is the key cytokine in the pathogenesis of pulmonary fibrosis. TGF-?-driven differentiation of fibroblasts into myofibroblasts is a key process in the pathogenesis of pulmonary fibrosis; however, the mechanisms of myofibroblast activation are not completely understood. In an unbiased approach using microarray studies, we identified Anoctamin-1 (ANO1), also known as TMEM16A, as one of highly upregulated genes in response to TGF-? contributing to the proliferation, migration and differentiation of lung fibroblasts to myofibroblasts. Our data also suggest that ANO1 is increased in the lungs of IPF patients and is localized to the fibrotic areas in the IPF lung. The role of ANO1 in myofibroblast activation and pulmonary fibrosis has been poorly investigated. Since ANO1 is a calcium-activated chloride channel, we evaluated the role of chloride-sensitive protein kinase, With-No-Lysine Kinase-1 (WNK1), which similarly to ANO1 contributed to myofibroblast activation. Based on our preliminary data, we hypothesize that ANO1 is a pro-fibrotic protein promoting myofibroblast activation and pulmonary fibrosis through WNK1 pathway. To test our hypothesis, we propose the following specific aims:
Specific Aim #1. Determine how ANO1-mediated control of intracellular chloride levels activates human lung fibroblasts (HLFs).
Specific Aim #2. Determine the signaling mechanisms of fibroblast activation through ANO1 and WNK1 in HLF.
Specific Aim #3. Elucidate the profibrotic role of ANO1 in the lung in vivo by a conditional knockout of ANO1 in fibroblasts.

Public Health Relevance

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease characterized by parenchymal fibrosis and structural distortion of the lungs, with no effective treatment. The myofibroblast is a key pathologic cell in pathogenesis of pulmonary fibrosis. We propose to elucidate the novel role of calcium-activated chloride channel, Anoctamine-1, and chloride-sensitive protein kinase, WNK1, in a control of myofibroblast differentiation and pulmonary fibrosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL149993-01A1
Application #
10052439
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Craig, Matt
Project Start
2020-08-15
Project End
2024-07-31
Budget Start
2020-08-15
Budget End
2021-07-31
Support Year
1
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637