title: Integrin αIIb (CD41) plays a role in the maintenance of hematopoietic stem cell activity in the mouse embryonic aorta.
abstract: Integrins are transmembrane receptors that play important roles as modulators of cell behaviour through their adhesion properties and the initiation of signaling cascades. The αIIb integrin subunit (CD41) is one of the first cell surface markers indicative of hematopoietic commitment. αIIb pairs exclusively with β3 to form the αIIbβ3 integrin. β3 (CD61) also pairs with αv (CD51) to form the αvβ3 integrin. The expression and putative role of these integrins during mouse hematopoietic development is as yet unknown. We show here that hematopoietic stem cells (HSCs) differentially express αIIbβ3 and αvβ3 integrins throughout development. Whereas the first HSCs generated in the aorta at mid-gestation express both integrins, HSCs from the placenta only express αvβ3, and most fetal liver HSCs do not express either integrin. By using αIIb deficient embryos, we show that αIIb is not only a reliable HSC marker but it also plays an important and specific function in maintaining the HSC activity in the mouse embryonic aorta.
authors.affiliation: Present address: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Boisset
authors.forename: Thomas
authors.initials: T
authors.lastname: Clapes
authors.forename: Reinier
authors.initials: R
authors.lastname: Van Der Linden
authors.forename: Elaine
authors.initials: E
authors.lastname: Dzierzak
authors.forename: Catherine
authors.initials: C
authors.lastname: Robin
keywords: Aorta; CD41; Fetal liver; Hematopoietic stem cells; Integrin; Mouse development; Placenta