The long-term objectives of our research focus on elucidation of the mechanisms that mediate controlled regulation of the extracellular matrix (ECM) turnover in healthy tissues and uncontrolled ECM turnover under pathological conditions. Excessive deposition of the ECM occurs in fibrotic diseases and is the main pathological manifestation of scleroderma (SSc), while accelerated ECM degradation occurs in the rheumatoid arthritis and during cancer progression and metastasis. During the previous funding period we proposed to test the hypothesis that constitutive upregulation of collagen and other ECM genes in SSc is caused by different expression levels and modification patterns of transcription factors involved in collagen gene expression by SSc fibroblasts. Our recent findings significantly strengthen this hypothesis. We demonstrated that Ets family transcription factors, particularly Fli-1, are important regulators of collagen homeostasis in healthy skin fibroblasts and among the key contributors to the excessive collagen production by SSc fibroblasts. We demonstrated that Fli-1 is a specific repressor of collagen gene transcription in cultured fibroblasts and in healthy skin in vivo. In addition, we made a novel observation that Fli-1 and Ets-1 are targeted by the TGF-beta signaling pathway, which induces rapid hyperacetylation of these proteins in healthy fibroblasts. In contrast, Fli-1 is constitutively hyperacetylated in SSc fibroblasts. Fli-l is also underexpressed in SSc fibroblasts in vitro. Significantly, during active stage of disease, Fli-1 protein is undetectable in fibroblasts in SSc lesions, correlated with increased collagen production. Based on these observations we hypothesize that in human dermal fibroblasts, Ets factors are the critical mediators of the fibrogenic TGF-beta signaling pathway and that alterations of the levels and acetylation status of Fli-1 contribute to dysregulation of ECM deposition in SSc. To test this hypothesis and to establish a direct linkage between Fli-1 and the development of fibrosis in SSc we propose five Specific Aims.
In Specific Aim 1 we will further delineate the role of Fli-1 in the formation of the multiprotein complex that regulates transcription of the COL 1A2 gene, focusing on the TGF-beta induced post-translational modifications of Fli-1, including acetylation and phosphorylation.
In Specific Aim 2 we will employ several approaches, including yeast two-hybrid screens to identify fibroblast-specific proteins that physically interact with Fli-1.
In Specific Aim 3 we will determine whether Fli-1 contributes to phenotypic alterations of SSc fibroblasts.
In Specific Aim 4 we will analyze in vivo expression of Fli-1 protein and its partners, as well as Fli-1 target genes in SSc and healthy skin biopsies.
In Specific Aim 5 we will use established animal models of SSc to determine the contribution of Fli-1 expression to fibrosis development in vivo.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR042334-13
Application #
7216319
Study Section
Special Emphasis Panel (ZRG1-GMA-1 (01))
Program Officer
Mancini, Marie
Project Start
1994-08-10
Project End
2008-03-31
Budget Start
2007-04-01
Budget End
2008-03-31
Support Year
13
Fiscal Year
2007
Total Cost
$247,797
Indirect Cost
Name
Medical University of South Carolina
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Stawski, Lukasz; Marden, Grace; Trojanowska, Maria (2018) The Activation of Human Dermal Microvascular Cells by Poly(I:C), Lipopolysaccharide, Imiquimod, and ODN2395 Is Mediated by the Fli1/FOXO3A Pathway. J Immunol 200:248-259
Toyama, Tetsuo; Looney, Agnieszka P; Baker, Brendon M et al. (2018) Therapeutic Targeting of TAZ and YAP by Dimethyl Fumarate in Systemic Sclerosis Fibrosis. J Invest Dermatol 138:78-88
Stawski, Lukasz; Trojanowska, Maria (2018) Oncostatin M and its role in fibrosis. Connect Tissue Res :1-10
Makino, Katsunari; Makino, Tomoko; Stawski, Lukasz et al. (2017) Anti-connective tissue growth factor (CTGF/CCN2) monoclonal antibody attenuates skin fibrosis in mice models of systemic sclerosis. Arthritis Res Ther 19:134
Takahashi, Takehiro; Asano, Yoshihide; Sugawara, Koji et al. (2017) Epithelial Fli1 deficiency drives systemic autoimmunity and fibrosis: Possible roles in scleroderma. J Exp Med 214:1129-1151
Farina, Antonella; Peruzzi, Giovanna; Lacconi, Valentina et al. (2017) Epstein-Barr virus lytic infection promotes activation of Toll-like receptor 8 innate immune response in systemic sclerosis monocytes. Arthritis Res Ther 19:39
Yamashita, Takashi; Asano, Yoshihide; Taniguchi, Takashi et al. (2017) Glycyrrhizin Ameliorates Fibrosis, Vasculopathy, and Inflammation in Animal Models of Systemic Sclerosis. J Invest Dermatol 137:631-640
Grzegorzewska, Agnieszka P; Seta, Francesca; Han, Rong et al. (2017) Dimethyl Fumarate ameliorates pulmonary arterial hypertension and lung fibrosis by targeting multiple pathways. Sci Rep 7:41605
Looney, Agnieszka P; Han, Rong; Stawski, Lukasz et al. (2017) Synergistic Role of Endothelial ERG and FLI1 in Mediating Pulmonary Vascular Homeostasis. Am J Respir Cell Mol Biol 57:121-131
Makino, Katsunari; Makino, Tomoko; Stawski, Lukasz et al. (2017) Blockade of PDGF Receptors by Crenolanib Has Therapeutic Effect in Patient Fibroblasts and in Preclinical Models of Systemic Sclerosis. J Invest Dermatol 137:1671-1681

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