[Effects of mesenchymal stem cells on expansion potential and adhesion molecules expression of cord blood CD34+ cells].
OBJECTIVE
To explore the effects of bone marrow mesenchymal stem cells (MSCs) on in vitro expansion potential, the adherent molecules expression of cord blood (CB) CD34(+) cells.


METHODS
MSCs were obtained from human bone marrow and their differentiation function and phenotype were identified. CB CD34(+) cells were expanded in culture systems with or without MSC layer. Hematopoietic progenitor cells and adhesion molecules expression were assessed by semisolid culture assay and flow cytometry.


RESULTS
Thy-1, SH2, SB10, CD44, CD13, CD49e and CD29 were highly expressed on MSCs with no expressions of CD34, CD45, HLA-DR, CD14 and CD31. The MSCs could differentiate into adipocytes and osteoblasts under specific induction conditions. After culturing on MSCs layer with supplement of cytokines for 8 days, the absolute numbers of nuclear cells, CD34(+), CD34(+)CD38(-), CD34(+)CD62L(+) cells and CFU-Cs were increased by 145.57 +/- 17.89, 37.47 +/- 13.78, 69.78 +/- 50.07, 10.74 +/- 5.89 and 20.73 +/- 5.54-folds, respectively, being significantly higher than that cultured with cytokines alone. The expression of ALCAM, VLA-alpha4, VLA-alpha5, VLA-beta1, HCAM, PECAM and LFA-1 on CD34(+) cells remained unaffected. The expressions of ICAM-1 and L-selectin were downregulated during expansion, while the absolute numbers of CD34(+)CD62L(+) and CD34(+)CD54(+) cells were increased.


CONCLUSIONS
MSCs layer improves expansion of CB CD34(+) cells while inhibiting their differentiation and retaining their homing ability.
Jang
Er-lie
EL
Institute of Hematology and Blood Diseases Hospital, CAMS & PUMC, Tianjin 300020, China.
Zhou
Zheng
Z
Huang
Yong
Y
Wang
He-hua
HH
Wang
Mei
M
Liu
Qing-guo
QG
Zhou
Shi-yong
SY
Yan
Zhang-song
ZS
Zhai
Wen-jing
WJ
Han
Ming-zhe
MZ
D018952:Antigens, CD34; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells
D018952:Antigens, CD34; D015815:Cell Adhesion Molecules