骨髓腔内途径脐血与间质干细胞共移植对造血重建的实验研究

目的：探讨骨髓腔内输注（IBM）脐血与间质干细胞（MSCs）对大鼠造血重建、骨髓MSCs恢复的影响，并研究供体MSCs植入状态以探讨MSCs的作用机制。方法：BrdU标记F344大鼠骨髓MSCs通过双侧胫骨IBM或尾静脉注射（IV）与胎鼠及新生大鼠外周血（FNPB）共移植Wistar雌鼠。监测受鼠存活状况、造血免疫重建、HSCs植入水平及骨髓MSCs恢复情况，并以免疫荧光法检测受鼠骨髓MSCs的来源。结果：(1)2个共移植组60 d存活率均为100%，单纯FNPB移植组仅为66.7%。(2)共移植组的外周血象、骨髓造血干祖细胞集落产率明显高于单纯FNPB移植组，尤以骨髓腔共移植组最佳。(3)2个共移植组的HSCs植入水平无统计学差异，而骨髓腔共移植组明显高于单纯FNPB移植组（P＜0.05）。(4)30 d时各移植组MSCs的增殖能力未达正常水平，但仍以骨髓腔共移植组的恢复情况最佳（P＜0.05）。(5)仅少部分受体可发现供、受体源性MSCs嵌合。 结论：脐血与MSCs共移植可促进受体骨髓MSCs恢复和造血重建，提高HSCs植入率；IBM途径应用安全，促进造血恢复的作用优于IV途径。

Effects of cotransplantation of umbilical cord blood and mesenchymal stem cells by intra-bone marrow injection on hematopoietic reconstitution in a rat model

AIM: To investigate the effects of cotransplantation of mesenchymal stem cells (MSCs) and umbilical cord blood (UCB) by intra-bone marrow (IBM) injection on the hematopoietic reconstitution and recovery of bone marrow MSCs in the recipients. METHODS: Wistar female rats were transplanted with fetal and neonatal peripheral blood (FNPB) and BrdU-labeled MSCs separated from BMNCs of F344 rats. The MSCs were infused by IBM injection in bilateral tibiae or intravenous injection (IV), while the FNPB was all via IBM route. The survival rate, reconstitution of hematopoietic and immunological function, engraftment level of HSCs and recovery of bone marrow (BM)-MSCs in recipients were monitored. The origins of BM-MSCs of recipients were examined by immunofluorescence assay. RESULTS: (1)The survival rate in the two cotransplantation groups was 100% at day 60, while that in FNPB group was only 66.7%. (2)The counts of peripheral blood cells and BM hematopoietic stem/progenitor cell colonies of the recipients were better in cotransplantation groups than those in FNPB group, especially in the FNPB (IBM)+MSC (IBM) group. (3)No significant difference between of engraftment level of HSCs in the two cotransplantation groups was observed. The percentage of RT1A1 cells subset in FNPB (IBM)+MSC (IBM) group was much higher than that in FNPB group (P<0.05). (4)At day 30, the growth characteristic of recipient BM-MSCs was still below normal, but that in FNPB (IBM)+MSC (IBM) group was the best of all the experiment groups (P<0.05). (5)The donor MSCs coexisted with host MSCs in only a few recipient rats. CONCLUSION: The cotransplantation of MSCs and FNPB can accelerate the recovery of recipient BM-MSCs and hematopoietic reconstitution, promote the engraftment level of HSCs. Cotransplantation by IBM route is safe and has better effects on hematopoietic reconstitution than by IV route.