A motif within the N-terminal domain of TSP-1 specifically promotes the proangiogenic activity of endothelial colony-forming cells.
Thrombospondin-1 (TSP-1) gives rise to fragments that have both pro- and anti-angiogenic effects in vitro and in vivo. The TSP-HepI peptide (2.3 kDa), located in the N-terminal domain of TSP-1, has proangiogenic effects on endothelial cells. We have previously shown that TSP-1 itself exhibits a dual effect on endothelial colony-forming cells (ECFC) by enhancing their adhesion through its TSP-HepI fragment while reducing their proliferation and differentiation into vascular tubes (tubulogenesis) in vitro. This effect is likely mediated through CD47 binding to the TSP-1 C-terminal domain. Here we investigated the effect of TSP-HepI peptide on the angiogenic properties of ECFC in vitro and in vivo. TSP-HepI peptide potentiated FGF-2-induced neovascularisation by enhancing ECFC chemotaxis and tubulogenesis in a Matrigel plug assay. ECFC exposure to 20 μg/mL of TSP-HepI peptide for 18 h enhanced cell migration (p < 0.001 versus VEGF exposure), upregulated alpha 6-integrin expression, and enhanced their cell adhesion to activated endothelium under physiological shear stress conditions at levels comparable to those of SDF-1α. The adhesion enhancement appeared to be mediated by the heparan sulfate proteoglycan (HSPG) syndecan-4, as ECFC adhesion was significantly reduced by a syndecan-4-neutralising antibody. ECFC migration and tubulogenesis were stimulated neither by a TSP-HepI peptide with a modified heparin-binding site (S/TSP-HepI) nor when the glycosaminoglycans (GAGs) moieties were removed from the ECFC surface by enzymatic treatment. Ex vivo TSP-HepI priming could potentially serve to enhance the effectiveness of therapeutic neovascularisation with ECFC.
Departamento de Biologia Celular, Laboratório de Biologia da Célula Endotelial e da Angiogênese (LabAngio), Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, UERJ, Rio de Janeiro, RJ, Brazil. juvbiodias@gmail.com
Juliana Vieira
JV
Dias
Zahia
Z
Benslimane-Ahmim
Marion
M
Egot
Anna
A
Lokajczyk
Françoise
F
Grelac
Isabelle
I
Galy-Fauroux
Luiz
L
Juliano
Bernard
B
Le-Bonniec
Cristina Maeda
CM
Takiya
Anne-Marie
AM
Fischer
Olivier
O
Blanc-Brude
Verônica
V
Morandi
Catherine
C
Boisson-Vidal
D000818:Animals; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D018919:Neovascularization, Physiologic / Q000502:physiology*; D019700:Thrombospondin 1 / Q000737:chemistry / Q000502:physiology*
D019700:Thrombospondin 1