小鼠脂肪源Flk1^+CD31^-CD34^-细胞促造血恢复作用观察

Observation of effect of mice adipose tissue-derived Flk1^+CD31^-CD34^-cells on supporting hematopoietic reconstitution

目的:观察小鼠成体脂肪源Flk1+CD31-CD34-细胞体内外能否促进造血恢复。方法:用小鼠脂肪源Flk1+CD31-CD34-细胞作滋养层,接种造血细胞,观察培养后1～4周造血细胞数及粒-巨噬细胞系集落形成单位(CFU-GM)的变化,并设对照组。30只经137Cs全身照射0.35Gy的雌性C57BL/6小鼠随机分为3组,空白对照组尾静脉注射生理盐水,对照组注射骨髓有核细胞,实验组注射骨髓有核细胞及脂肪源Flk1+CD31-CD34-细胞,注射后均检测外周血和骨髓有核细胞数及CFU-GM变化,PCR检测受体小鼠体内Y染色体的表达。结果:体外实验中实验组接种后2～4周造血细胞数均高于对照组(P均<0.05),接种后1～4周CFU-GM值均高于对照组(P均<0.05);体内实验中空白对照组小鼠移植后10d左右死亡,实验组小鼠外周血和骨髓有核细胞数、CFU-GM从第2周起均高于对照组(P均<0.05),第4周实验组小鼠骨髓细胞有Y染色体表达。结论:脂肪源Flk1+CD31-CD34-细胞能促进小鼠造血恢复。

Aim ： To explore whether mice adipose tissue-derived Flk1^＋CD31^-CD34^- cells could enhance hematopoiesis recovery in vivo as well as facilitate proliferation and differentiation of hematopoietic cells in vitro. Methods： Hemantopoietic cells were plated onto a feeder layer formed by mice adipose tissue-derived Flk1^＋CD31^-CD34^- cells, cell count and CFU-GM yields were observed dynamically. In addition, the control groups were planned. Totally 30 femal C57BL/6 mice received 0.35 Gy 137Cs were divided into 3 groups. The blank control groups received only saline infusion. The control groups received infusion of bone marrow-derived mononuclear cells, while the experimental groups were systemically infused with adipose tissue-derived Flk1^＋CD31^-CD34^- cells and bone marrow-derived mononuclear cells. Peripheral granulocytic count, cells in the bone marrow and CFU-GM yields in all mice were assayed. At the time, the expression of Y-chromosome in recipient mice were examined by PCR. Results： In vitro, the totle cell count and CFU-GM yields in the experimental group were higher than those of the long-term culture bone marrow cells （ P 〈 0.05 ）. The mice adipose tissue-derived Flk1^＋CD31^-CD34^- cells could sufficiently support the proliferation and differentiation of hemantopoietic cells （P 〈 0.05 ）. In vivo, peripheral granulocytic conut, cells in the bone marrow of one femoral bone and CFU-GM by the second week in the the experimental group were much higher than those of controls （P 〈 0.05 ） , and Y-chromosome-specific PCR to detect the distribution of donor-derived cells in adult adipose tissue-derived Flk1^＋CD31^-CD34^- cells-transplantated mice. Conclusion ： Mice adipose tissue-derived Flk1^＋CD31^-CD34^- cells have the characteristics of enhancing hematopoietic recovery.