title: Irradiation induces homing of donor endothelial progenitor cells in allogeneic hematopoietic stem cell transplantation.
abstract: Functional abnormalities of the endothelial system may be caused by allogeneic hematopoietic stem cell transplantation (HSCT). The aim of this study is to explore the possibility that endothelial progenitor cells (EPCs) can be used in endothelial repair post-HSCT. EPCs were isolated from mouse bone marrow by density centrifugation and differential adherence. Numbers of endothelial cells (ECs) (CD31(+)CD133(-)CD45(-)), EPCs (CD31(+)CD133(+)-CD45(low/-)) and carboxyfluorescein succinimidyl ester (CFSE)-positive cells in peripheral blood, spleen and bone marrow were determined at various time points by flow cytometry. The distribution of labeled EPCs was observed by fluorescence microscopy; morphological alterations of tissues were assessed by light microscopy and transmission electron microscopy. In the irradiated group, the numbers of circulating ECs and EPCs were elevated after pre-conditioning, reaching peaks at days 3 and 5; the counts remained high for about 5 days. In addition, CFSE-labeled cells were visualized in tissue and bone marrow. In conclusion, these results suggest the following: (a) the EPCs derived from mouse bone marrow mononuclear cells express phenotypes characteristic of normal EPCs, (b) irradiation during preconditioning damaged the endothelium, which initiated mobilization of EPCs, and (c) injury to the endothelium also caused extrinsic EPCs home to the damaged tissue.
authors.affiliation: Laboratory of Transplantation and Immunology, Xuzhou Medical College, Xuzhou, People's Republic of China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Zeng
authors.forename: Shuang
authors.initials: S
authors.lastname: Ding
authors.forename: Zhiling
authors.initials: Z
authors.lastname: Yan
authors.forename: Chong
authors.initials: C
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Sang
authors.forename: Jiang
authors.initials: J
authors.lastname: Cao
authors.forename: Hai
authors.initials: H
authors.lastname: Cheng
authors.forename: Kailin
authors.initials: K
authors.lastname: Xu
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000473:pathology / Q000528:radiation effects; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology / Q000528:radiation effects*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology*; D004730:Endothelium, Vascular / Q000473:pathology / Q000528:radiation effects; D006085:Graft Survival / Q000502:physiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D019172:Transplantation Conditioning / Q000009:adverse effects / Q000379:methods; D014184:Transplantation, Homologous; D014916:Whole-Body Irradiation / Q000009:adverse effects*