Wnt3 modulates the characteristics and cobblestone area-supporting activity of human stromal cells.
OBJECTIVE
Our objective was to investigate the expression and significance of Wnt proteins in adult human hematopoietic-supporting stromal cells.


METHODS
Degenerate reverse transcription-polymerase chain reaction was performed to screen telomerized human stromal cells (hTERT-stromal cells) and multipotent mesenchymal cells (hTERT-MSCs) for expression of Wnt genes. We studied the actions of Wnt proteins by overexpressing them in stromal cells and MSCs by retrovirus-mediated gene transfer.


RESULTS
The hTERT-stromal and primary stromal cells expressed Wnt5A, while hTERT-MSCs and primary MSCs expressed Wnt3 and Wnt5A. Gene transfer of Wnt5A slightly reduced the growth rate of hTERT-stromal cells, but did not affect their morphology. In contrast, gene transfer of Wnt3 into both hTERT-stromal cells and hTERT-MSCs enhanced Wnt-betacatenin signaling, and caused remarkable morphological changes and growth retardation. Upon 2-week co-culture, expansion of clonogenic cells on Wnt5A-stromal cells was superior to that on control stromal cells. However, expansion of CD34+ cells on Wnt3-stromal cells did not differ from that on control stromal cells. Moreover, there was a drastic reduction in the formation of cobblestone area (CA) underneath Wnt3-stromal cells compared with that underneath control stromal cells.


CONCLUSIONS
These results suggest that Wnt3 plays an important role in regulating characteristics and CA support activity of stromal cells.
Chiba
Hiroki
H
Forth Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
Kobune
Masayoshi
M
Kato
Junji
J
Kawano
Yutaka
Y
Ito
Yoshinori
Y
Nakamura
Kiminori
K
Asakura
Sumiyo
S
Hamada
Hirofumi
H
Niitsu
Yoshiro
Y
D018952:Antigens, CD34 / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D048708:Cell Growth Processes / Q000235:genetics / Q000502:physiology; D018920:Coculture Techniques; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology; D006801:Humans; D008648:Mesoderm / Q000166:cytology* / Q000502:physiology; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000502:physiology*; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D014161:Transduction, Genetic; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein
D018952:Antigens, CD34; D011506:Proteins; D011518:Proto-Oncogene Proteins; C555507:WNT3 protein, human; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060508:Wnt3 Protein; D019098:Telomerase