中文摘要：

目的探讨人脐血源基质细胞（hUCBDSCs）移植重建裸鼠造血微环境对巨核细胞生成的促进作用。方法取63只雌性BALB/c-nu/nu裸鼠,经5.0Gy^60Coγ射线照射后,随机分为对照组、人骨髓基质细胞（hBMSCs）组和hUCBDSCs组（n=21）,分别输注生理盐水、hBMSCs（1×10^5/只）和hUCBDSCs（1×10^5/只）,观察移植后1、3、5、7、10、14、21d裸鼠血小板计数（PLT）变化,以及移植后1、7、14、21d的巨核细胞数、类成纤维细胞集落形成单位（CFU-F）、骨髓象和骨髓病理组织变化。结果3组裸鼠移植后PLT、巨核细胞和CFU-U计数均降低（P〈0.05）,其中hUCBDSCs组裸鼠以上3个指标降低程度最轻（P〈0.05）,且恢复速度优于hBMSCs组和对照组（P〈0.05）。hUCBDSCs组移植后骨髓抑制程度减轻,所有裸鼠均健康存活。结论hUCBDSCs具备修复造血微环境、促进巨核细胞增殖和血小板生成的作用,输注hUCBDSCs可作为一种安全有效的促进放/化疗或造血干细胞移植后血小板数量和功能恢复的方法。

英文摘要：

Objective To observe the reconstruction of hematopoietic inductive microenvironment （HIM） and the recovery of megakaryocytes in nude mouse, after transplantation of human umbilical cord blood-derived stromal cells （hUCBDSCs）. Methyls Sixty- three 6w-old female BALB/c-nu/nu nude mice placed in ventilated Plexiglas boxes were exposed to 5.0Gy ^60Co γ ray （dose rate 120cGy/ min） to damage their hematopoietic microenviroment. The animals received a transplantation of hUCBDSCs 24h after the exposure in a concentration of 1×10^5 cells （0. 3ml of the cell suspension was injected through the tail vein）. Human bone marrow stromal ceils （hBMSCs, 1×10^5 cells/0. 3ml） or equal volume of isotonic sodium chloride were injected through the tail vein as controi. After the transplantation, the changes in platelet count, megakaryocyte count, CFU-F, bone marrow biopsy and pathology were observed on ＋1d, ＋3d, ＋5d, ＋ 7d, ＋10d, ＋14d and ＋21days, respectively. Results Platelet, megakaryocyte and CFU-F counts declined 5--7 days after translpantation （P〈0. 05）. The nadirs of platelet, megakaryocyte and CFU-F counts were 148 ± 18 × 10^9/L, 137 ± 35/slide and 88 ± 3/dish in hUCBDSCs group, being higher than that in hBMSCs group and isotonic NaCl group （P〈0. 05）. The platelet, megakaryocyte and CFU-F counts in hUCBDSCs group recovered 21 days after transplantation to the level of that before transplantation, and they were also higher than that in hBMSCs group and isotonic NaCl group （P〈0. 05）. More fibroblasts were seen to be disposed beside the bone trabecula in orderly fashion in hUCBSCs group than in hBMSC group and isotonic NaCl group. Condusion hUCBSCs transplantation may enhance the recovery of hematopoietic microenviroument in irradiated nude mice, especially the recovery of megakaryocytes and platelets, hUCBDSCs transplantation should be looked as a safe and effective way for recovery of megakaryocytes and platelets after chemotherapy, radiotherapy and hematopoietic stem cel