[Biological characteristics of mesenchymal stem cells in human umbilical cord blood and their supporting capacities in ex vivo expansion of CD34+ hematopoietic stem cells].
OBJECTIVE
To explore the biological characteristics of mesenchymal stem cells (MSC) derived from umbilical cord blood (UCB) and their supporting capacities in ex vivo expansion of hematopoietic stem/progenitor cells (HSPCs).


METHODS
Low-density mononuclear cells (MNCs) from UCB were cultured in IMDM containing 20% FBS to form confluent adherent cells through 15 passages. Some cytokines in the conditioned medium were determined with ELISA. UCB-derived adherent cells were displayed with antibodies and analyzed with flow cytometry. The supporting capacity of UCB-derived adherent cells for ex vivo expansion of CD34(+) cells was assayed by co-culture in a two step culture. UCB-derived adherent cells were induced for chondrogenic differentiation with chondrogenic medium, and the induced cells were analyzed for the type II pro-collagen gene expression with RT-PCR.


RESULTS
The mean number of adherent fibroblast like colonies derived from UCB was (3.5 +/- 0.7)/10(6) MNCs. UCB-derived MSCs could survive for at least 15 passages of expansion. In their undifferentiated status, UCB-derived MSCs were CD13(+), CD29(+), CD90(+), CD105(+), CD166(+), SH2(+), SH3(+), SH4(+), CD45(-), CD34(-), and CD14(-). Stem cell factor (SCF), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) could be detected in the supernatant of the cultures. The MSCs cultured in chondrogenic media could differentiate into chondrogenic cells and express type II pro-collagen mRNA. UCB-derived MSCs could support the proliferation and differentiation of UCB CD34(+) cells in vitro.


CONCLUSIONS
UCB-derived MSCs are similar to those derived from adult bone marrow and can support the proliferation of hematopoietic stem/progenitor cells.
Wang
Li-juan
LJ
College of Life Sciences, Zhejiang University, Hangzhou 310012, China.
Zhang
Ye-ping
YP
Wang
Jin-fu
JF
Wu
Yi-fan
YF
Xiang
Ying
Y
Xie
Chun-gang
CG
Jia
Bing-bing
BB
Harrington
Jenny
J
McNiece
Ian K
IK
D018952:Antigens, CD34 / Q000378:metabolism; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D024043:Collagen Type II / Q000235:genetics; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005312:Fetal Blood / Q000166:cytology*; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D018952:Antigens, CD34; D024043:Collagen Type II; D016207:Cytokines