TeKippe Michael, Harrison David E, Chen Jichun
The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA.
Exp Hematol. 2003 Jun;31(6):521-7. doi: 10.1016/s0301-472x(03)00072-9.
To study the effects of transformation-related protein 53 (Trp53) and other genes on hematopoiesis and hematopoietic stem cells (HSCs).
Frequencies of murine bone marrow cells (BMCs) with the Lin(-)Sca-1(+)c-kit(+)CD34- phenotype were analyzed by flow cytometry, and were increased in mice with germ-line deletion of the Trp53 (Trp53(-/-)) gene but not in 25 other deletions of genes involved in cell cycling, development, cancer, or hematopoiesis. Therefore, Trp53(-/-) and wild-type Trp53(+/+) mice were compared using the following assays: complete blood counts, day-9 colony-forming unit spleen (CFU-S), and competitive repopulation. In the latter assay, donor repopulating ability was analyzed at one, three, and five months, while recipient survival and recipient blood and bone marrow cell composition were analyzed at five months, after transplantation.
In comparison to wild-type controls, Trp53(-/-) mice had normal blood and bone marrow cell counts, increased CD11b(+), and decreased CD45R(+) cell proportions in blood and bone marrow, twice as many Lin(-)Sca-1(+)c-kit(+)CD34(-) BMCs, and 37% more day-9 CFU-S. In the competitive repopulation assay, Trp53(-/-) BMCs engrafted lethally irradiated recipients two to four times better than Trp53(+/+) BMCs. The Trp53(-/-) engraftment advantage increased with time in the recipients. Recipients of Trp53(-/-) donors had two to three times more Lin(-)Sca-1(+)c-kit(+)CD34(-) BMCs than recipients of Trp53(+/+) donors at five months after transplantation. However, only 44% of recipients of Trp53(-/-) donors survived five months after trans-plantation, compared with 92% of recipients of Trp53(+/+) donors.
The Trp53-null allele expands bone marrow Lin(-)Sca-1(+)c-kit(+)CD34(-) cells and the overall activity of HSCs; however, it increases recipient mortality.
研究转化相关蛋白53（Trp53）及其他基因对造血作用和造血干细胞（HSCs）的影响。
采用流式细胞术分析具有Lin(-)Sca-1(+)c-kit(+)CD34-表型的小鼠骨髓细胞（BMCs）频率，发现Trp53（Trp53(-/-)）基因种系缺失的小鼠中该频率增加，而在其他25种参与细胞周期、发育、癌症或造血的基因缺失小鼠中未增加。因此，使用以下检测方法比较Trp53(-/-)和野生型Trp53(+/+)小鼠：全血细胞计数、第9天脾集落形成单位（CFU-S）和竞争性重建造血。在后者检测中，移植后1个月、3个月和5个月分析供体的重建造血能力，5个月时分析受体的存活情况以及受体血液和骨髓细胞组成。
与野生型对照相比，Trp53(-/-)小鼠血液和骨髓细胞计数正常，血液和骨髓中CD11b(+)细胞比例增加，CD45R(+)细胞比例降低，Lin(-)Sca-1(+)c-kit(+)CD34(-) BMCs数量是野生型的两倍，第9天CFU-S多37%。在竞争性重建造血检测中，Trp53(-/-) BMCs对致死性照射受体的植入效果比Trp53(+/+) BMCs好2至4倍。Trp53(-/-)的植入优势随受体时间延长而增加。移植后5个月，Trp53(-/-)供体受体的Lin(-)Sca-1(+)c-kit(+)CD34(-) BMCs数量比Trp53(+/+)供体受体多2至3倍。然而，Trp53(-/-)供体受体中只有44%在移植后5个月存活，而Trp53(+/+)供体受体的这一比例为92%。
Trp53无效等位基因可使骨髓Lin(-)Sca-1(+)c-kit(+)CD34(-)细胞及造血干细胞的整体活性增加；然而，它会增加受体死亡率。
