The overall goal of our work is to elucidate the molecular mechanisms of yolk sac blood island organogenesis. These studies will provide new insights into the relationship between blood and endothelial cell development in the first site of blood cell production. To date, reagents to identify the earliest events in yolk sac hematopoiesis have been lacking. We present novel preliminary data that CD41 expression marks the onset of primitive and definitive hematopoiesis in the murine embryo. We have utilized confocal microscopy to identify the site of emergence of the progenitor cells of both primitive and definitive progenitors and have developed a strategy that permits isolation of primitive erythroid progenitor cells (EryP) from embryos or embryonic stem cell-derived embryoid bodies. We propose 3 aims to define the roles of specific molecules in the process of blood island organogenesis: 1. To determine the mechanism of EryP migration and expansion in the proximal yolk sac. We hypothesize that EryP migration and expansion in the proximal yolk sac are VEGF dependent. 2. To define the mechanism of angioblast and extracellular matrix fibronectin (Fn) interaction that results in blood island organogenesis. We hypothesize that blood island formation and remodeling into a capillary bed is a Fn dependent process whereby angioblasts migrate via integrin-Fn interactions to circumscribe the band of primitive erythroblasts in the proximal yolk sac to form intact blood islands. 3. To determine the mechanism of CD41 bright cell cluster formation. We hypothesize that CD41 bright cell clusters require the expression of Runxl and GATA2 for emergence from the endothelial cells located between blood islands and pre-established capillaries (devoid of blood cells) in the distal yolk sac. These studies will define molecular pathways required for blood island development and remodeling.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL063169-09
Application #
7391197
Study Section
Hematopoiesis Study Section (HP)
Program Officer
Thomas, John
Project Start
1999-07-01
Project End
2009-03-31
Budget Start
2008-04-01
Budget End
2009-03-31
Support Year
9
Fiscal Year
2008
Total Cost
$401,529
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
Arora, Natasha; Wenzel, Pamela L; McKinney-Freeman, Shannon L et al. (2014) Effect of developmental stage of HSC and recipient on transplant outcomes. Dev Cell 29:621-628
Swiers, Gemma; Baumann, Claudia; O'Rourke, John et al. (2013) Early dynamic fate changes in haemogenic endothelium characterized at the single-cell level. Nat Commun 4:2924
Qu, Peng; Shelley, William C; Yoder, Mervin C et al. (2010) Critical roles of lysosomal acid lipase in myelopoiesis. Am J Pathol 176:2394-404
Stumpo, Deborah J; Broxmeyer, Hal E; Ward, Toni et al. (2009) Targeted disruption of Zfp36l2, encoding a CCCH tandem zinc finger RNA-binding protein, results in defective hematopoiesis. Blood 114:2401-10
Pierre, Monique; Yoshimoto, Momoko; Huang, Lan et al. (2009) VEGF and IHH rescue definitive hematopoiesis in Gata-4 and Gata-6-deficient murine embryoid bodies. Exp Hematol 37:1038-53
Rhodes, Katrin E; Gekas, Christos; Wang, Yanling et al. (2008) The emergence of hematopoietic stem cells is initiated in the placental vasculature in the absence of circulation. Cell Stem Cell 2:252-63
Yoshimoto, Momoko; Porayette, Prashanth; Yoder, Mervin C (2008) Overcoming obstacles in the search for the site of hematopoietic stem cell emergence. Cell Stem Cell 3:583-6
Ghiaur, Gabriel; Ferkowicz, Michael J; Milsom, Michael D et al. (2008) Rac1 is essential for intraembryonic hematopoiesis and for the initial seeding of fetal liver with definitive hematopoietic progenitor cells. Blood 111:3313-21
Lux, Christopher T; Yoshimoto, Momoko; McGrath, Kathleen et al. (2008) All primitive and definitive hematopoietic progenitor cells emerging before E10 in the mouse embryo are products of the yolk sac. Blood 111:3435-8
Chan, Rebecca J; Li, Yanjun; Hass, Meredith N et al. (2006) Shp-2 heterozygous hematopoietic stem cells have deficient repopulating ability due to diminished self-renewal. Exp Hematol 34:1230-9

Showing the most recent 10 out of 37 publications