During lung development FGF10 (Fibroblast growth factor 10) is secreted by the parabronchial smooth muscle cell (PSMC) progenitors in the distal mesenchyme and activates the canonical WNT signaling pathway in the distally located epithelial progenitors to maintain them and sustain their proliferation. Our recently published results indicate that in the embryonic lung, (-catenin signaling in the PSMC progenitors is also essential for their maintenance and proliferation. The goal in this proposal is to determine if this pathway can be reactivated in adults to promote reepithelialization of damaged airway epithelium. Our preliminary findings illustrate reactivation of this embryonic signaling cascade in the mature PSMCs shortly after naphthalene injury. After naphthalene injury some of the PSMCs show activated TOPGAL activity, as a readout for activated (-catenin signaling, undergo massive proliferation as monitored by BrdU incorporation and reexpress Fgf10. Our data suggest that this paracrine FGF10 signaling by the PSMCs is critical for epithelial repair after naphthalene injury possibly by activating the latent bronchioalveolar stem cells (BASCs) at the Bronchio-alveolar duct junctions (BADJs). Our preliminary data also indicate an additional cellular contribution by the PSMCs in epithelial repair after naphthalene injury. We show that mature PSMCs can dedifferentiate and undergo Mesenchymal to Epithelial Transition (MET) to contribute directly to the epithelial repair process. This suggests a dual major role for the PSMCs in epithelial repair after naphthalene injury. Hypothesis: Dedifferentiation of parabronchial smooth muscle cells and/or their recapitulation of a progenitor like phenotype, is critical for epithelial regeneration after injury.
Aim 1 : To determine the differentiation status of the surrounding (non-epithelial) """"""""niche"""""""" cells after naphthalene injury and their potential paracrine role in epithelial regeneration after naphthalene injury.
Aim 2 : To determine the differentiation status and cellular contribution of the PSMCs to epithelial repair after naphthalene injury.

Public Health Relevance

Remodeling of the airway epithelium is a common pathological feature in chronic lung disease and a predisposing factor in the development of lung cancer. Accordingly, understanding cellular and molecular mechanisms of epithelial maintenance and repair are fundamental to the development of improved therapeutic modalities for the treatment of chronic lung disease. We hypothesize that after epithelial injury, the surrounding non-epithelial cells get reprogrammed to contribute, directly and indirectly be secreting growth factors, to the epithelial repair.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL092967-05
Application #
8423356
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Blaisdell, Carol J
Project Start
2009-03-01
Project End
2014-02-28
Budget Start
2013-03-01
Budget End
2014-02-28
Support Year
5
Fiscal Year
2013
Total Cost
$367,567
Indirect Cost
$131,947
Name
National Jewish Health
Department
Type
DUNS #
076443019
City
Denver
State
CO
Country
United States
Zip Code
80206
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Al Alam, Denise; El Agha, Elie; Sakurai, Reiko et al. (2015) Evidence for the involvement of fibroblast growth factor 10 in lipofibroblast formation during embryonic lung development. Development 142:4139-50
Volckaert, Thomas; De Langhe, Stijn P (2015) Wnt and FGF mediated epithelial-mesenchymal crosstalk during lung development. Dev Dyn 244:342-66
Li, Changgong; Li, Min; Li, Sha et al. (2015) Progenitors of secondary crest myofibroblasts are developmentally committed in early lung mesoderm. Stem Cells 33:999-1012
Carraro, Gianni; Shrestha, Amit; Rostkovius, Jana et al. (2014) miR-142-3p balances proliferation and differentiation of mesenchymal cells during lung development. Development 141:1272-81
Volckaert, Thomas; Campbell, Alice; De Langhe, Stijn (2013) c-Myc regulates proliferation and Fgf10 expression in airway smooth muscle after airway epithelial injury in mouse. PLoS One 8:e71426
Volckaert, Thomas; Campbell, Alice; Dill, Erik et al. (2013) Localized Fgf10 expression is not required for lung branching morphogenesis but prevents differentiation of epithelial progenitors. Development 140:3731-42
El Agha, Elie; Al Alam, Denise; Carraro, Gianni et al. (2012) Characterization of a novel fibroblast growth factor 10 (Fgf10) knock-in mouse line to target mesenchymal progenitors during embryonic development. PLoS One 7:e38452
Tiozzo, Caterina; Danopoulos, Soula; Lavarreda-Pearce, Maria et al. (2012) Embryonic epithelial Pten deletion through Nkx2.1-cre leads to thyroid tumorigenesis in a strain-dependent manner. Endocr Relat Cancer 19:111-122
Tiozzo, Caterina; Carraro, Gianni; Al Alam, Denise et al. (2012) Mesodermal Pten inactivation leads to alveolar capillary dysplasia- like phenotype. J Clin Invest 122:3862-72

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