[Irradiation-induced homing of donor endothelial progenitor cells in mice allo-HSCT model].
OBJECTIVE
To investigate the effect of allo-HSCT irradiation preconditioning on the homing of donor endothelial progenitor cells (EPCs).


METHODS
The mononuclear cells were collected form mice bone morrows, then cultured in EGM-2 medium. The cells were identified after 5-7 days and were labeled with CFSE. The mice were divided randomly into four groups, control, EPCs transplantation, irradiation, and irradiation EPCs transplantation. The circulating ECs, circulating EPCs and CFSE positive cells in the peripheral blood, spleen and bone morrows of the mice were measured by FCS. The histological examination, electron microscope and immunofluorescence analyses of those tissues were also performed. The distribution of labeled EPCs was observed.


RESULTS
The cells were identified as CD45low, CD133+ CD31+, Dil-ac-LDL+. The number of those cells in the irradiation group increased gradually after preconditioning and reached peak at day 3 or 5 and sustained the peak level for 2 days, which was significantly different from the control (P < 0.05). Under the light microscopy and TEM, damaged endothelium was detected. In the irradiation and EPCs transplantation groups, CFSE labeled cells increased and reached peak at 18 hours, and then decreased till 72 hours. Green fluorescent cells were observed in different tissues at different times, and the strongest fluorescence intensity occurred at 36 hours.


CONCLUSIONS
The EPCs can be induced from mice bone morrow mononuclear cells, with expressed phenotypic characterization. Irradiation in transplantation preconditioning can cause severe endothelium injury, which can start the mobilization of EPCs. The endothelium injury can induce extrinsic EPCs homing to the tissues which are badly injured. Endothelial progenitor cells
Ding
Shuang
S
Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, China.
Xu
Kai-lin
KL
Yan
Zhi-ling
ZL
Chen
Chong
C
Pan
Xiu-ying
XY
Zeng
Ling-yu
LY
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000473:pathology / Q000502:physiology / Q000528:radiation effects*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D007963:Leukocytes, Mononuclear / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011897:Random Allocation; D013234:Stem Cells / Q000473:pathology / Q000502:physiology* / Q000528:radiation effects*; D019172:Transplantation Conditioning / Q000009:adverse effects* / Q000379:methods