| Project/Area Number |
12557080
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
Hematology
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
NAKANO Toru Department of Molecular Cell Biology, Research Institute for Microbial Diseases, Osaka University, 微生物病研究所, 教授 (00172370)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OSAWA Masaki Kirin Brewery Research Center, 医薬探索研究所, 研究員(研究職)
MATSUMOTO Kayoko Osaka Red Cross Research Center, 研究部, 課長(研究職)
木村 透 大阪大学, 微生物病研究所, 助教授 (50280962)
鈴木 聡 大阪大学, 微生物病研究所, 講師 (10311565)
大沢 匡毅 麒麟ビール, 医薬探索研究所, 研究員
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 2001: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2000: ¥9,300,000 (Direct Cost: ¥9,300,000)
|
|---|
| Keywords | Hematopoiesis / Embryonic Stem Cell / Cell Differentiation / Transcription Factor / GATA-2 / Gene Regulation / Stroma Cell / 細胞分化 / GATA転写因子 / Myb転写因子 |
|---|
| Research Abstract |
We had established an in vitro differentiation induction method from mouse embryonic stem (ES) cells to hematopoietic cells by co-culturing the ES cells on OP9 stroma cell line (OP9 system). Although OP9 system can give rise to multipotential hematopoietic progenitors, hematopoietic stem cells with self-renewing activity never emerge. To improve the hematopoietic activity, we introduced conditional gene expression method to OP9 system. Combination of tetracycline gene regulating system (Tet-Off system) and OP9 system enabled us to express the desirable genes in the hematopoietic progenitor cells which are developed by OP9 system.
Function of a zinc-finger type transcription factor GATA-2 was examined by the system. When GATA-2 was over-expressed, the numbers of hematopoietic colonies and the percentages of immature hematopoietic cells in individual colonies increased to 10 fold. Previous reports had suggested that GATA-2 inhibited the terminal differentiation of blood cells. However, our data was opposite ; i.e., terminal differentiation into erythroid and megakaryocyte lineages were enhanced. We speculated that this discrepancy should have been due to the adopted experimental system, since the previous studies used the fusion protein of GATA-2 and the ligand binding domain of estrogen receptor (GATA-2/ER) for conditional activation of the transcription factor instead of the authentic GATA-2. Then, we compared the biological functions of GATA-2 and GATA-2/ER. Surprisingly, the function of GATA-2 was opposite to that of GATA-2/ER. Binding capacity and inhibitory transcriptional interaction of GATA-2 to the other hematopoietic transcription factors, PU.1 and c-Myb, were quite different from those of GATA-2/ER.
This study reveals the utility of the combination of OP9 system and Tet-Off system to investigate the molecular mechanisms of hematopoietic differentiation and for the future regenerative medicine.
|
