Idiopathic pulmonary fibrosis (IPF) is an inexorably progressive disease, but the rate of progression is variable and at times can be catastrophic. The mechanisms that regulate abrupt acceleration or rapid progression of disease are completely unknown. We have reported that aberrant innate sensing of hypomethylated DNA in lung myofibroblasts drives the rapid progression of fibrosis via endosomal TLR9 activation. More recently, we have discovered that a cytoplasmic and nuclear DNA sensor known as DNA- protein kinase (DNA-PK) is also present in human primary fibroblasts, and this sensor is also involved in the responsiveness of IPF fibroblasts to a hypomethylated DNA (i.e. CpG-DNA) signal. Additional preliminary data we have generated suggest that innate DNA sensors promote myofibroblast activation and accelerate fibrosis via a pathway that involves type 1 interferon alpha (IFN?), growth arrest specific-6 (Gas6), and Axl (a Gas6 receptor). Using this framework of published and unpublished data, the present grant will address the following specific hypothesis: hypomethylated DNA drives the activation of DNA sensors in primary human pulmonary fibroblasts leading to myofibroblast differentiation and activation via a targetable IFN?- Gas6-Axl receptor-dependent mechanism. Finally, we have data suggesting that this process is a vicious cycle in which Gas6/Axl interactions drive the expression of TLR9 and DNA-PK in IPF fibroblasts. Thus our proposed studies will focus on the following Specific Aims: 1) Determine the role of innate DNA sensors in the activation of normal and IPF fibroblasts. 2) Determine the role of type 1 IFN? in the activation of normal and IPF fibroblasts. 3) Determine the role of Gas6-Axl in the activation of normal and IPF fibroblasts. We will examine primary human fibroblasts propagated from either stable and progressive forms of IPF or normal lung samples for the presence of DNA sensors and their downstream signaling components. The primary human fibroblasts will be interrogated for the signaling mechanism(s) via which innate DNA sensing drives myofibroblast differentiation, synthetic activity, and invasiveness (i.e. migratory behavior). Finally, we will use a humanized model of IPF initiated by the intravenous introduction of primary human fibroblasts into immunodeficient mice with the goal of further interrogating and therapeutically targeting the DNA sensing mechanisms leading to rapid fibrosis in vivo. Thus, this translational proposal will address the molecular mechanisms through which primary human fibroblasts are activated by exogenous hypomethylated DNA, and will seek to identify therapeutic strategies that interrupt this process during the exacerbation or rapid progression of pulmonary fibrosis.

Public Health Relevance

Idiopathic pulmonary fibrosis (IPF) is a chronic fibro-proliferative disease with profound clinical and economic impact. This proposal will address a mechanism to explain why a distinct subset of IPF patients shows a rapidly progressive form of this disease whereas other IPF patients exhibit a more stable disease phenotype with a more gradual decline in lung function. Thus, this proposal will define mechanisms that contribute to and therapeutic strategies that interrupt the progression of IPF.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL123899-01A1
Application #
8886551
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Harabin, Andrea L
Project Start
2015-09-01
Project End
2019-06-30
Budget Start
2015-09-01
Budget End
2016-06-30
Support Year
1
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Cedars-Sinai Medical Center
Department
Type
DUNS #
075307785
City
Los Angeles
State
CA
Country
United States
Zip Code
90048
Espindola, Milena S; Habiel, David M; Hogaboam, Cory M (2018) Reply to D'Alessandro-Gabazza et al.: Risks of Treating Idiopathic Pulmonary Fibrosis with a TAM Receptor Kinase Inhibitor. Am J Respir Crit Care Med 198:971-973
Espindola, Milena S; Habiel, David M; Narayanan, Rohan et al. (2018) Targeting of TAM Receptors Ameliorates Fibrotic Mechanisms in Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med 197:1443-1456
Griffiths, K; Habiel, D M; Jaffar, J et al. (2018) Anti-fibrotic Effects of CXCR4-Targeting i-body AD-114 in Preclinical Models of Pulmonary Fibrosis. Sci Rep 8:3212
Cavassani, Karen A; Meza, Rebecca J; Habiel, David M et al. (2018) Circulating monocytes from prostate cancer patients promote invasion and motility of epithelial cells. Cancer Med 7:4639-4649
Schuliga, Michael; Pechkovsky, Dmitri V; Read, Jane et al. (2018) Mitochondrial dysfunction contributes to the senescent phenotype of IPF lung fibroblasts. J Cell Mol Med 22:5847-5861
Skalski, Joseph H; Limon, Jose J; Sharma, Purnima et al. (2018) Expansion of commensal fungus Wallemia mellicola in the gastrointestinal mycobiota enhances the severity of allergic airway disease in mice. PLoS Pathog 14:e1007260
Habiel, David M; Espindola, Milena S; Coelho, Ana L et al. (2018) Modeling Idiopathic Pulmonary Fibrosis in Humanized Severe Combined Immunodeficient Mice. Am J Pathol 188:891-903
Habiel, David M; Espindola, Milena S; Jones, Isabelle C et al. (2018) CCR10+ epithelial cells from idiopathic pulmonary fibrosis lungs drive remodeling. JCI Insight 3:
Hartl, Dominik; Tirouvanziam, Rabindra; Laval, Julie et al. (2018) Innate Immunity of the Lung: From Basic Mechanisms to Translational Medicine. J Innate Immun 10:487-501
Cooke, G; Kamal, I; Strengert, M et al. (2018) Toll-like receptor 3 L412F polymorphism promotes a persistent clinical phenotype in pulmonary sarcoidosis. QJM 111:217-224

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