[在异种移植BALB/c小鼠模型中用肿瘤坏死因子α处理后提高人造血干/祖细胞归巢至骨髓效率的机制研究]

[Study on the mechanism of enhancing homing efficiency of human hematopoietic stem/progenitor cells into bone marrow after manipulation with tumor necrosis factor alpha in xenotransplanted BALB/c mouse model].

作者信息

Dai Hong-sheng, Gao Jing-tao, Zhang Tong-wen, Yang Zhou, Che Yong-zhe, Zheng Yi-zhou

机构信息

State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, CAMS & PUMC, Tianjin 300020, China.

出版信息

Zhonghua Xue Ye Xue Za Zhi. 2009 Feb;30(2):97-102.

PMID:19563019

Abstract

OBJECTIVE

To investigate the role of tumor necrosis factor (TNF) alpha on the homing efficiency of hematopoietic stem/progenitor cells (HS/PC) into bone marrow and its mechanism.

METHODS

CFSE-labeled umbilical cord blood (UCB) CD34+ cells were transplanted into irradiated (control group) or combined with TNF alpha prepared (experimental group) BALB/c recipient mice. The distribution in peripheral blood, liver, lung and homing characteristics in bone marrow and spleen of UCB CD34+ cells, in BALB/c recipient mice were determined 20 hours after xenotransplantation by flow cytometry (FACS) and their homing efficiency was calculated. ELISA was used to measure serum SDF-1 alpha level. CXCR4 expression levels of on UCB CD34+ cells were assessed by FACS pre-/post-manipulation with TNF alpha. SDF-1 alpha expression level in bone marrow and spleen was tested by immunohistochemistry.

RESULTS

UCB CD34+ cells mainly home into recipient mice bone marrow and spleen; The homing efficiency in experimental group bone marrow [(0.65 +/- 0.13)%] was significantly higher than that in control ones [(0.30 +/- 0.09)%, P < 0.01], whereas the homing efficiency in experimental group spleen was dramatically lower than that in control ones (P < 0.01); Treatment with TNF alpha did not affect recipient serum SDF-1 alpha level; After 18 hours co-cultured with TNF alpha, the CXCR4e expression level on UCB CD34+ cells was similar to that on fresh ones; TNF alpha treatment induced significantly higher SDF-1 alpha expression on osteoblastic and stromal cells in bone marrow, and reversed spleen SDF-1 alpha gradient that was originally favorable for CD34+ cells homing.

CONCLUSION

TNF alpha enhances the homing efficiency of HS/PC via up-regulating SDF-1 alpha gradient in bone marrow, and might be an useful enhancer for HS/PC homing in clinical practice.

摘要

目的

探讨肿瘤坏死因子（TNF）α对造血干/祖细胞（HS/PC）归巢至骨髓的效率及其机制的影响。

方法

将羧基荧光素二乙酸琥珀酰亚胺酯（CFSE）标记的脐带血（UCB）CD34⁺细胞移植到经照射的（对照组）或联合制备的TNFα的（实验组）BALB/c受体小鼠体内。异种移植20小时后，通过流式细胞术（FACS）测定BALB/c受体小鼠外周血、肝脏、肺中UCB CD34⁺细胞的分布以及骨髓和脾脏中的归巢特征，并计算其归巢效率。采用酶联免疫吸附测定（ELISA）法检测血清基质细胞衍生因子-1α（SDF-1α）水平。通过FACS在TNFα处理前后评估UCB CD34⁺细胞上的CXCR4表达水平。采用免疫组织化学法检测骨髓和脾脏中SDF-1α表达水平。

结果

UCB CD34⁺细胞主要归巢至受体小鼠的骨髓和脾脏；实验组骨髓中的归巢效率[（0.65±0.13）%]显著高于对照组[（0.30±0.09）%，P<0.01]，而实验组脾脏中的归巢效率显著低于对照组（P<0.01）；TNFα处理不影响受体血清SDF-1α水平；与TNFα共培养18小时后，UCB CD34⁺细胞上的CXCR4表达水平与新鲜细胞相似；TNFα处理显著诱导骨髓中成骨细胞和基质细胞上SDF-1α表达升高，并逆转了原本有利于CD34⁺细胞归巢的脾脏SDF-1α梯度。