Endothelial NOS is required for SDF-1alpha/CXCR4-mediated peripheral endothelial adhesion of c-kit+ bone marrow stem cells.
In the era of intravascular approaches for regenerative cell therapy, the underlying mechanisms of stem cell migration to non-marrow tissue have not been clarified. We hypothesized that next to a local inflammatory response implying adhesion molecule expression, endothelial nitric oxide synthase (eNOS)-dependent signaling is required for stromal- cell-derived factor-1 alpha (SDF-1alpha)-induced adhesion of c-kit+ cells to the vascular endothelium. SDF-1alpha/tumor necrosis factor-alpha (TNF-alpha)-induced c-kit+-cell shape change and migration capacity was studied in vitro using immunohistochemistry and Boyden chamber assays. In vivo interaction of c-kit+ cells from bone marrow with the endothelium in response to SDF-1alpha/TNF-alpha stimulation was visualized in the cremaster muscle microcirculation of wild-type (WT) and eNOS (-/-) mice using intravital fluorescence microscopy. In addition, NOS activity was inhibited with N-nitro-L-arginine-methylester-hydrochloride in WT mice. To reveal c-kit+-specific adhesion behavior, endogenous leukocytes (EL) and c-kit+ cells from peripheral blood served as control. Moreover, intercellular adhesion molecule-1 (ICAM-1) and CXCR4 were blocked systemically to determine their role in inflammation-related c-kit+-cell adhesion. In vitro, SDF-1alpha enhanced c-kit+-cell migration. In vivo, SDF-1alpha alone triggered endothelial rolling-not firm adherence-of c-kit+ cells in WT mice. While TNF-alpha alone had little effect on adhesion of c-kit+ cells, it induced maximum endothelial EL adherence. However, after combined treatment with SDF-1alpha+TNF-alpha, endothelial adhesion of c-kit+ cells increased independent of their origin, while EL adhesion was not further incremented. Systemic treatment with anti-ICAM-1 and anti-CXCR4-monoclonal antibody completely abolished endothelial c-kit+-cell adhesion. In N-nitro-L-arginine-methylester-hydrochloride-treated WT mice as well as in eNOS (-/-) mice, firm endothelial adhesion of c-kit+ cells was entirely abrogated, while EL adhesion was significantly increased. The chemokine SDF-1alpha mediates firm adhesion c-kit+ cells only in the presence of TNF-alpha stimulation via an ICAM-1- and CXCR4-dependent mechanism. The presence of eNOS appears to be a crucial and specific factor for firm c-kit+-cell adhesion to the vascular endothelium.
Kaminski
Alexander
A
Department of Cardiac Surgery, University of Rostock, Rostock, Germany. alexander.kaminski@med.uni-rostock.de
Ma
Nan
N
Donndorf
Peter
P
Lindenblatt
Nicole
N
Feldmeier
Gregor
G
Ong
Lee-Lee
LL
Furlani
Dario
D
Skrabal
Christian A
CA
Liebold
Andreas
A
Vollmar
Brigitte
B
Steinhoff
Gustav
G
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D002469:Cell Separation; D054377:Chemokine CXCL12 / Q000502:physiology*; D004727:Endothelium / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D005434:Flow Cytometry; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000502:physiology*
C514936:CXCR4 protein, mouse; D054377:Chemokine CXCL12; D019718:Receptors, CXCR4; D052250:Nitric Oxide Synthase Type III; D019009:Proto-Oncogene Proteins c-kit