Our long-term goal is to identify the mechanism(s) that Fanconi anemia (FA) proteins have in protecting hematopoietic stem/progenitor cells (HS/Ps) from apoptosis in order to design targeted therapies for prevention/treatment of bone marrow failure in FA. 80% of FA patient deaths are a direct result of a progressive marrow failure. Thus, understanding mechanisms involved in the apoptotic predisposition of FA HS/Ps is of critical importance and clinically relevant. Currently, little is known regarding the function(s) that individual FA proteins have in maintaining HS/Ps survival. Using a murine model of FA type C, we previously showed that Fancc -/- stem cells have a marked reduction in repopulating ability and Fame -/- progenitors exhibit enhanced inhibitory cytokine-induced apoptosis. Preliminary data also show that Fancc /- progenitors are hypersensitive to oxidants. Our central hypothesis is that loss of IIS/Ps via altered inhibitory cytokine and oxidant apoptotic signaling has a crucial role in the development of marrow failure in FA-C patients. Previous structure-function studies in cell lines demonstrated 2 FANCC functions, separable by FANCC"""""""" mutants. One (1) function was to protect from genotoxins, and the other was to enhance survival after IFN-y/TNF-a treatment by inhibiting double-stranded RNA-dependent kinase (PKR)-mediated apoptosis. While these studies begin to clarify distinct FANCC functions in cell lines, a critical yet unanswered question is whether these 2 functions exhibit equally important roles in enhancing the survival of primary HS/Ps. Furthermore, our preliminary data suggest that FANCC may protect cells from TNF-a and oxidant induced apoptosis through an apoptosis signal-regulating kinase 1 (ASK1) dependent pathway. We hypothesize that Fancc -/- cells exhibit both altered ASK1 and PKR apoptotic signaling, which contribute to the pro-apoptotic phenotype of Fancc -/ HS/Ps after oxidant or inhibitory cytokine treatment. The goals of this application are, 1) to determine whether PKR-dependent and -independent FANCC functions enhance Fancc -/- stem cell repopulating ability and protect from inhibitory cytokine and genotoxin treatment in vivo, 2) to determine whether ASK1 participates in Fancc -/- HS/Ps hypersensitivity to apoptotic stimuli and repopulating ability, and 3) to investigate whether inhibitory cytokine hypersensitivity in primary Fancc -/- cells involves alterations in both ASK1 and PKR apoptotic signaling.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL077175-03
Application #
7258877
Study Section
Hematopoiesis Study Section (HP)
Program Officer
Qasba, Pankaj
Project Start
2005-07-01
Project End
2009-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
3
Fiscal Year
2007
Total Cost
$287,299
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Pediatrics
Type
Schools of Medicine
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Liu, Ying; Ballman, Kimberly; Li, Deqiang et al. (2012) Impaired function of Fanconi anemia type C-deficient macrophages. J Leukoc Biol 91:333-40
Rhee, David B; Wang, Yisong; Mizesko, Melissa et al. (2010) FANCC suppresses short telomere-initiated telomere sister chromatid exchange. Hum Mol Genet 19:879-87
Saadatzadeh, M Reza; Bijangi-Vishehsaraei, Khadijeh; Kapur, Reuben et al. (2009) Distinct roles of stress-activated protein kinases in Fanconi anemia-type C-deficient hematopoiesis. Blood 113:2655-60
Case, Jamie; Ingram, David A; Haneline, Laura S (2008) Oxidative stress impairs endothelial progenitor cell function. Antioxid Redox Signal 10:1895-907
Haneline, Laura S (2008) Redox regulation of stem and progenitor cells. Antioxid Redox Signal 10:1849-52
Li, Binghui; Jia, Nan; Waning, David L et al. (2007) Cul4A is required for hematopoietic stem-cell engraftment and self-renewal. Blood 110:2704-7
Ingram, David A; Krier, Theresa R; Mead, Laura E et al. (2007) Clonogenic endothelial progenitor cells are sensitive to oxidative stress. Stem Cells 25:297-304
Haneline, Laura S; White, Hilary; Yang, Feng-Chun et al. (2006) Genetic reduction of class IA PI-3 kinase activity alters fetal hematopoiesis and competitive repopulating ability of hematopoietic stem cells in vivo. Blood 107:1375-82
Bijangi-Vishehsaraei, Khadijeh; Saadatzadeh, M Reza; Werne, Adam et al. (2005) Enhanced TNF-alpha-induced apoptosis in Fanconi anemia type C-deficient cells is dependent on apoptosis signal-regulating kinase 1. Blood 106:4124-30