Idiopathic pulmonary fibrosis (IPF) is a progressive and frequently fatal disorder for which there are currently no effective treatment strategies. The current proposal focuses on Interleukin-1 (IL-1), a potent, pro-inflammatory cytokine that induces multiple signaling cascades in fibroblasts. These signals serve in host defense but, paradoxically, may contribute to inflammatory tissue injury and to fibrosis of the lung and other organs. IL-1 stimulates Ca2+ release and expression of multiple cytokines and inflammatory factors such as matrix metalloproteinases (MMPs) that drive extracellular matrix degradation via mitogen activated protein (MAP) kinase pathways. Currently, the mechanisms by which IL-1-induced signals are moderated or terminated are incompletely understood. Our studies to date have determined that in fibroblasts, IL-1-induced signaling requires focal adhesions (FA) and that IL-1 signals are dissipated by FA dispersing peptides that we have developed. Our recent studies indicate the importance of two protein tyrosine phosphatases (PTP), SHP- 2 and PTP(, in the regulation of IL-1-induced FA maturation and IL-1 induced signals. We discovered that SHP-2 mediates functional interactions between focal adhesions and the endoplasmic reticulum that are crucial for ER Ca2+ release;these interactions, together with focal adhesions, are central determinants of IL-1 signaling. Our hypothesis is that the PTP( in FA mediates maturation and remodeling of FA in response to IL- 1. In these multi-molecular signaling platforms, PTP( interacts with and dephosphorylates SHP-2, leading to recruitment and activation of additional signaling and scaffold molecules that are essential for Ca2+ release from the endoplasmic reticulum, signaling to ERK, and MMP-1 and 3 secretion.
In Specific Aim 1 we will determine how PTP( regulates FA-dependent IL-1 signaling leading to ERK activation and MMP-1 and 3 secretion. We will use cultured human lung fibroblasts from normals and IPF lungs and murine fibroblasts from SHP-2 or PTP(-null embryos, reconstituted with wild type or mutant proteins, as in vitro models to study FA-restricted signaling. ERK activation and MMP1 and 3 release will be used as outcomes of IL-1 signaling to assess the impact of SHP-2 and PTP(.
In Specific Aim 2, we will determine the role of PTP( in regulating IL-1 signaling through focal adhesions and the ER. We will examine the molecular determinants of PTP( and SHP-2 interactions and how they regulate the IP3 receptor and other FA-dependent signals leading to MMP expression.
In Specific Aim 3, we will assess the roles of PTP( and MMP3 in vivo in a murine model of bleomycin-induced pulmonary fibrosis. We will also examine potential alterations in PTP( and SHP-2 expression and/or activation in samples of banked lung tissue from patients with pulmonary fibrosis. These samples will be used to determine if there are alterations in the expression of SHP2 and PTP( mRNA and protein in the lungs of these patients that are associated with severity of pulmonary fibrosis. As IL-1 is a critical mediator of chronic inflammatory conditions such as pulmonary fibrosis, elucidation of IL-1 signaling pathways is fundamental in the identification of specific targets for effective anti-inflammatory agents. This is exemplified by small molecule inhibitors of specific PTP and peptides designed to selectively interfere with pro-fibrotic pathways as potential therapeutics. PROJECT NARRATIVE: Pulmonary fibrosis (scarring of the lung) is a progressive and usually fatal disorder for which there is currently no effective therapy. It is currently believed that the scarring process is started by damage to the lining cells of the lung (epithelium), perhaps as the result of a viral infection or from environmental pollutants. We have discovered that Interleukin-1, a small molecule secreted by the cells lining the lung, strongly promotes pathways leading to scarring in the lung. We propose to characterize these pathways with the aim of identifying specific targets for therapies to curtail this devastating process.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL090669-03
Application #
7879340
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Reynolds, Herbert Y
Project Start
2008-07-08
Project End
2012-06-30
Budget Start
2010-07-01
Budget End
2011-06-30
Support Year
3
Fiscal Year
2010
Total Cost
$390,000
Indirect Cost
Name
National Jewish Health
Department
Type
DUNS #
076443019
City
Denver
State
CO
Country
United States
Zip Code
80206
Wang, Qin; Wang, Yongqiang; Downey, Gregory P et al. (2016) A ternary complex comprising FAK, PTP? and IP3 receptor 1 functionally engages focal adhesions and the endoplasmic reticulum to mediate IL-1-induced Ca2+ signalling in fibroblasts. Biochem J 473:397-410
Schmidt, Eric P; Kuebler, Wolfgang M; Lee, Warren L et al. (2016) Adhesion Molecules: Master Controllers of the Circulatory System. Compr Physiol 6:945-73
Aschner, Yael; Zemans, Rachel L; Yamashita, Cory M et al. (2014) Matrix metalloproteinases and protein tyrosine kinases: potential novel targets in acute lung injury and ARDS. Chest 146:1081-1091
Burnham, Ellen L; Janssen, William J; Riches, David W H et al. (2014) The fibroproliferative response in acute respiratory distress syndrome: mechanisms and clinical significance. Eur Respir J 43:276-85
Redente, Elizabeth F; Keith, Rebecca C; Janssen, William et al. (2014) Tumor necrosis factor-? accelerates the resolution of established pulmonary fibrosis in mice by targeting profibrotic lung macrophages. Am J Respir Cell Mol Biol 50:825-37
Wang, Qin; Wang, Yongqiang; Fritz, Dominik et al. (2014) Interactions of the protein-tyrosine phosphatase-? with the focal adhesion targeting domain of focal adhesion kinase are involved in interleukin-1 signaling in fibroblasts. J Biol Chem 289:18427-41
Aschner, Yael; Khalifah, Anthony P; Briones, Natalie et al. (2014) Protein tyrosine phosphatase ? mediates profibrotic signaling in lung fibroblasts through TGF-? responsiveness. Am J Pathol 184:1489-502
Rajshankar, Dhaarmini; Sima, Corneliu; Wang, Qin et al. (2013) Role of PTP? in the destruction of periodontal connective tissues. PLoS One 8:e70659
Zemans, Rachel L; McClendon, Jazalle; Aschner, Yael et al. (2013) Role of ?-catenin-regulated CCN matricellular proteins in epithelial repair after inflammatory lung injury. Am J Physiol Lung Cell Mol Physiol 304:L415-27
Dengler, Viola; Downey, Gregory P; Tuder, Rubin M et al. (2013) Neutrophil intercellular communication in acute lung injury. Emerging roles of microparticles and gap junctions. Am J Respir Cell Mol Biol 49:1-5

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