title: Human CD133+ progenitor cells promote the healing of diabetic ischemic ulcers by paracrine stimulation of angiogenesis and activation of Wnt signaling.
abstract: We evaluated the healing potential of human fetal aorta-derived CD133(+) progenitor cells and their conditioned medium (CD133(+) CCM) in a new model of ischemic diabetic ulcer. Streptozotocin-induced diabetic mice underwent bilateral limb ischemia and wounding. One wound was covered with collagen containing 2x10(4) CD133(+) or CD133(-) cells or vehicle. The contralateral wound, covered with only collagen, served as control. Fetal CD133(+) cells expressed high levels of wingless (Wnt) genes, which were downregulated following differentiation into CD133(-) cells along with upregulation of Wnt antagonists secreted frizzled-related protein (sFRP)-1, -3, and -4. CD133(+) cells accelerated wound closure as compared with CD133(-) or vehicle and promoted angiogenesis through stimulation of endothelial cell proliferation, migration, and survival by paracrine effects. CD133(+) cells secreted high levels of vascular endothelial growth factor (VEGF)-A and interleukin (IL)-8. Consistently, CD133(+) CCM accelerated wound closure and reparative angiogenesis, with this action abrogated by co-administering the Wnt antagonist sFRP-1 or neutralizing antibodies against VEGF-A or IL-8. In vitro, these effects were recapitulated following exposure of high-glucose-primed human umbilical vein endothelial cells to CD133(+) CCM, resulting in stimulation of migration, angiogenesis-like network formation and induction of Wnt expression. The promigratory and proangiogenic effect of CD133(+) CCM was blunted by sFRP-1, as well as antibodies against VEGF-A or IL-8. CD133(+) cells stimulate wound healing by paracrine mechanisms that activate Wnt signaling pathway in recipients. These preclinical findings open new perspectives for the cure of diabetic ulcers.
authors.affiliation: Bristol Heart Institute, University of Bristol, Upper Maudlin Street, Bristol, United Kingdom.
authors.forename: Lucíola S
authors.initials: LS
authors.lastname: Barcelos
authors.forename: Cécile
authors.initials: C
authors.lastname: Duplaa
authors.forename: Nicolle
authors.initials: N
authors.lastname: Kränkel
authors.forename: Gallia
authors.initials: G
authors.lastname: Graiani
authors.forename: Gloria
authors.initials: G
authors.lastname: Invernici
authors.forename: Rajesh
authors.initials: R
authors.lastname: Katare
authors.forename: Mauro
authors.initials: M
authors.lastname: Siragusa
authors.forename: Marco
authors.initials: M
authors.lastname: Meloni
authors.forename: Ilaria
authors.initials: I
authors.lastname: Campesi
authors.forename: Manuela
authors.initials: M
authors.lastname: Monica
authors.forename: Andreas
authors.initials: A
authors.lastname: Simm
authors.forename: Paola
authors.initials: P
authors.lastname: Campagnolo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mangialardi
authors.forename: Lara
authors.initials: L
authors.lastname: Stevanato
authors.forename: Giulio
authors.initials: G
authors.lastname: Alessandri
authors.forename: Costanza
authors.initials: C
authors.lastname: Emanueli
authors.forename: Paolo
authors.initials: P
authors.lastname: Madeddu